Presentation on theme: "PENGELOLAAN RTH KOTA Sumber:. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry 2007. 33(3):220–226. David J. Nowak,"— Presentation transcript:
PENGELOLAAN RTH KOTA Sumber:
Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Urban forests in the coterminous United States are estimated to produce ≈61 million metric tons (67 million tons) of oxygen annually, enough oxygen to offset the annual oxygen consumption of approximately two-thirds of the U.S. population. Although oxygen production is often cited as a significant benefit of trees, this benefit is relatively insignificant and of negligible value as a result of the large oxygen content of the atmosphere. Other benefits of the urban forest are more critical to environmental quality and human health than oxygen production by urban trees.
. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Urban vegetation, particularly trees, provides numerous benefits that can improve environmental quality and human health in and around urban areas. These benefits include improvements in air and water quality, building energy conservation, cooler air temperatures, reductions in ultraviolet radiation, and many other environmental and social benefits (Nowak and Dwyer 2007). 1.Nowak, D.J., and J.F. Dwyer Understanding the benefits and costs of urban forest ecosystems, pp. 25–46. In Urban and Community Forestry in the Northeast. Kuser, J., Ed. Springer Science and Business Media, New York, NY.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Urban forests produce large amounts of oxygen. However, with the large and relatively stable amount of oxygen in the atmosphere and extensive production by aquatic systems, this tree benefit is relatively insignificant. Tree impacts on important atmospheric trace chemicals such as carbon dioxide and air pollutants (ozone, particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead) will have greater significant impacts on human health and environmental quality. Urban forest carbon sequestration and air pollution removal along with other environmental impacts of urban forests (e.g., water quality improvement, lower air temperatures, reduced ultraviolet radiation loads) need to be better incorporated within local and regional planning efforts to improve environmental quality and enhance the quality of urban life.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Oxygen Production by Trees Net oxygen production by trees is based on the amount of oxygen produced during photosynthesis minus the amount of oxygen consumed during plant respiration (Salisbury and Ross 1978): Photosynthesis: n(CO2) + n(H2O) + light → (CH2O)n + nO2 Respiration: (CH2O)n + nO2 → n(CO2) + n(H2O) + energy If carbon dioxide uptake during photosynthesis exceeds carbon dioxide release by respiration during the year, the tree will accumulate carbon (carbon sequestration). Thus, a tree that has a net accumulation of carbon during a year (tree growth) also has a net production of oxygen. The amount of oxygen produced is estimated from carbon sequestration based on atomic weights: net O2 release (kgyr) = net C sequestration (kgyr) × Salisbury, F.B., and C.W. Ross Plant Physiology. Wadsworth Publishing Company, Belmont, CA. 422 pp.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Tree Biomass The net amount of oxygen produced by a tree during a year is directly related to the amount of carbon sequestered by the tree, which is tied to the accumulation of tree biomass. Biomass for each measured tree was calculated using equations from the literature with inputs of dbh and tree height (Nowak et al. 2002a). Equations that predict aboveground biomass were converted to whole tree biomass based on a belowground to aboveground ratio of 0.26 (Cairns et al. 1997). Equations that compute fresh weight biomass were multiplied by species- or genus- specific conversion fac tors to yield dry weight biomass. These conversion factors, derived from average moisture contents of species given in the literature, averaged 0.48 for conifers and 0.56 for hardwoods (Nowak 1994). 1.Cairns, M.A., S. Brown, E.H. Helmer, and G.A. Baumgardner Root biomass allocation in the world’s upland forests. Oecologia 111:1–11. 2.Nowak,D.J Atmospheric carbon dioxide reduction by Chicago’s urban forest, pp. 83–94. In Chicago’s Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project. McPherson, E.G., Nowak, D.J., and Rowntree, R.A., Eds. USDA Forest Service General Technical Report NE-186, Radnor, PA. 3.Nowak, D.J., D.E. Crane, J.C. Stevens, and M. Ibarra. 2002a. Brooklyn’s Urban Forest. General Technical Report NE- 290, U.S. Department of Agriculture, Forest Service, Northeastern Research Station, Newtown Square, PA. 107 pp.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Tree Biomass Open-grown, maintained trees tend to have less aboveground biomass than predicted by forest-derived biomass equations for trees of the same diameter at breast height (Nowak 1994). To adjust for this difference, biomass results for open-grown urban trees were multiplied by a factor of 0.8 (Nowak 1994). No adjustment was made for trees found in more natural stand conditions (e.g., vacant lands, forest preserves). Because deciduous trees drop their leaves annually, only carbon stored in woody biomass was calculated for these trees. Total tree dry weight biomass (above- and belowground) was converted to total stored carbon by multiplying by Nowak,D.J Atmospheric carbon dioxide reduction by Chicago’s urban forest, pp. 83–94. In Chicago’s Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project. McPherson, E.G., Nowak, D.J., and Rowntree, R.A., Eds. USDA Forest Service General Technical Report NE-186, Radnor, PA.
Pertumbuhan pohon kota dan penangkapan karbon Rata-rata pertumbuhan diameter pohon dari rata-rata guna-lahan dan kelas diameter ditambahkan pada diameter pohon saat sekarang (tahun ke X) untuk estimasi diameter pohon tahun ke X+1 estimate tree diameter in year x + 1. Untuk pohon kota dalam vegetasi hutan, rata-rata pertumbuhan dbh diperkirakan sebesar 0.38 cm/ tahun (Smith and Shifley 1984); untuk pohon pada vegetasi taman kota, rata-rata pertumbuhan dbh sebesar 0.61 cm/tahun (deVries 1987); untuk pohon yang tumbuh di tempat yang lebih terbuka, laju pertumbuhan dbh didasarkan pada hasil penelitian Nowak (1994). Rata-rata pertumbuhan tinggi pohon dihitung berdasarkan pada formula Fleming (1988) dan faktor pertumbuhan dbh untuk pohon ini bersifat spesifik. 1.deVries, R.E A preliminary investigation of the growth and longevity of trees in Central Park. New Brunswick, NJ, Rutgers University, MS thesis. 2.Fleming, L.E Growth estimation of street trees in central New Jersey. New Brunswick, NJ, Rutgers University. MS thesis. 3.Nowak,D.J Atmospheric carbon dioxide reduction by Chicago’s urban forest, pp. 83–94. In Chicago’s Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project. McPherson, E.G., Nowak, D.J., and Rowntree, R.A., Eds. USDA Forest Service General Technical Report NE-186, Radnor, PA. 4.Smith, W.B., and S.R. Shifley Diameter Growth, Survival, and Volume Estimates for Trees in Indiana and Illinois. Res. Pap. NC-257. U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN. Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Pertumbuhan pohon kota dan penangkapan karbon Laju pertumbuhan pohon ditentukan oleh kondisi tajuk pohon. Faktor koreksinya sebanding dengan persentase kematian tajuk ( semakin besar tingkat kematian tajuk, laju pertumbuhan pohon semakin lambat) dan asumsinya adalah kematian tajuk kurang dari 25% mempunyai pengaruh yang sangat kecil (dapat diabaikan) terhadap laju pertumbuhan dbh. Untuk pohon dnegan kondisi yang cukup baik (tingkat kematian tajuk kurang dari 25%), tidak perlu koreksi laju pertumbuhan; untuk pohon yang kondisinya buruk ( tingkat kematian tajuk 26% hingga 50%), laju pertumbuhan pohon dikalikan dengan faktor 0.76; untuk pohon yang kritis (tingkat kematian tajuk 51% - 75%) faktor koreksinya 0.42; pohon yang sedang mengalami kematian (tingkat kematian tajuk 76% - 99%) faktor koreksinya 0.15; dan pohon yang mati faktor koreksinya 0. Perbedaan estimasi simpanan karbon antara tahun ke X dan tahun ke X+1 merupakan jumlah neto karbon yang ditangkap dan disimpan setiap tahun.
Pertumbuhan pohon kota dan penangkapan karbon Kematian pohon mengakibatkan pelepasan karbon yang tersimpan dalam biomasa pohon. Untuk estimasi jumlah karbon yang ditangkap oleh pohon kota setelah dekomposisi, emisi karbon yang dihaislkan oleh dekomposisi bahan organik setelah pohon mati harus dipertimbangkan. Untuk menghitung potensial pelepasan karbon dari kematian pohon dan dekomposisi biomasanya, estimasi laju mortalitas tahunan sesuai dnegan kondisi habitatnya dapat diperoleh dari penelitian mortalitas pohon-jalur hijau jalan raya (Nowak 1986). Mortalitas tahunan diestimasi sebesar 1.9% untuk pohon yang mempunyai dbh 0-3 inch dalam kondisi pertumbuhan yang bagus (tingkat kematian tajuk kurang dari 10%); 1.5% untuk pohon yang dbh nya lebih besar dari 3 inch pada kondisi yang bagus; 3.3% untuk pohon yang cukup baik (tingkat kematian tajuk 11% - 25%); 8.9% untuk kondisi buruk; 13.1% untuk kondisi pohon kritis; 50% untuk pohon yang sedang mengalami kematian; dan 100% untuk pohon yang mati. 1.Nowak, D.J Silvics of an urban tree species: Norway maple (Acer platanoides L.). Syracuse, NY, State University of New York, College of Environmental Science and Forestry, MS thesis. Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Urban Tree Growth and Carbon Sequestration. Two types of decomposition rates were used: 1.Rapid release for aboveground biomass of trees that are projected to be removed and 2.Delayed release for standing dead trees and tree roots of removed trees. Trees that are removed from urban sites are not normally developed into wood products that provide for long-term carbon storage (i.e., removed trees are often burned or mulched); therefore, they will most likely release their carbon relatively soon after removal.
.. Oxygen Production by Urban Trees in the United States. Arboriculture & Urban Forestry (3):220–226. David J. Nowak, Robert Hoehn, and Daniel E. Crane Urban Tree Growth and Carbon Sequestration If dead trees are not removed annually, they have an increased probability of being measured in the tree sample, and decomposition rates must reflect this difference. All trees on vacant, transportation, and agriculture land uses, and 50% of trees in parks, were assumed to be left standing (i.e., not removed) because these trees are likely within forest stands and/or away from intensively maintained sites. These trees were assumed to decompose over a period of 20 years. Data on tree decomposition rates are limited. However, using decomposition rates from 10 to 50 years had little effect on overall net decomposition within a single year. Trees on all other land uses were assumed to be removed within 1 year of tree death. For removed trees, aboveground biomass was assumed to be mulched with a decomposition rate of 3 years; below-ground biomass was assumed to decompose in 20 years. Although no mulch decomposition studies could be found, studies on decomposition reveal that 37% to 56% of carbon in tree roots and 48% to 67% of carbon in twigs is released within the first 3 years (Scheu and Schauermann 1994). 1.Scheu, S., and J. Schauermann Decomposition of roots and twigs: Effects of wood type (beech and ash), diameter, site of exposure and macro fauna exclusion. Plant and Soil 163:13–24.
Pertumbuhan pohon kota dan penangkapan karbon Estimasi emisi karbon dari dekomposisi biomasa pohon didasarkan pada peluang kematian pohon di dalam tahun mendatang dan peluang pohon ditebang, dengan formula: Emisi = C × Mc × Σpi((Dremove) + (Dstand)) Dremove = (pabyi)(1dm) + ((1−pab)yi)(1dr) Dstand = ((yi−1)yi)(1dr) Dimana : Emisi = kontribusi individu pohon pada emisi karbon; C = simpanan karbon pada tahun mendatang; Mc = peluang mortalitas berdasarkan kelas-kondisi pertumbuhan pohon; i = Kelas dekomposisi (berdasarkan pada jumlah tahun sebelum pohon mati atau ditebang); pi = proporsi populasi pohon dalam landuse pada kelas dekomposisi i; pab = proporsi biomasa bagian pohon di atas tanah; yi = jumlah tahun sebelum pohon ditebang (yi → ∞ untuk pohon mati yang tidak pernah ditebang (dekomposisi alamiah); dm = Laju dekomposi untuk biomasa mulsa di atas tanah (3 tahun); dan dr = Laju dekomposi untuk pohon hidup dan akar pohon (20 tahun). Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Konsumsi Oksigen Manusia Rata-rata konsumsi oksigen orang dewasa sebesar 0.84 kg/hari (1.85 lb/day) (Perry dan LeVan, 2003). Nilai ini digunakan untuk estimasi berapa banyak konsumsi oksigen manusia dapat dipenuhi oleh produksi oksigen hutan kota setiap tahun. Untuk estimasi jumlah konsumsi oksigen manusia dapat dipenuhi oleh hutan kota, produksi oksigen hutan kota dibagi dnegan rata-rata konsumsi oksigen tahunan setiap orang. 1.Perry, J., and M.D. LeVan Air Purification in Closed Environments: Overview of Spacecraft Systems. U.S. Army Natrick Soldier Center. jocotas/ColPro_Papers/Perry-LeVan.pdf.http://nsc.natick.army.mil/ Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Produksi oksigen oleh pohon ternyata beragam dengan ukuran pohon. Berdasarkan data dari Minneapolis, Minnesota (Nowak et al., 2006b), pohon yang mempunyai dbh 1–3 dapat memproduksi ≈2.9 kg O2/tahun (6.4 lb O2/year); pohon-pohon dengan dbh 9–12 : 22.6 kg O2/tahun (49.9 lb O2/year); pohon dnegan dbh 18–21 : 45.6 kg O2/tahun (100.5 lb O2/year); pohon-pohon dnegan dbh 27–30 : 91.1 kg O2/tahun (200.8 lb O2/year); dan pohon-pohon yang mempunyai dbh lebih dari 30 : kg O2/tahun (243.2 lb O2/year). 1.Nowak, D.J., R. Hoehn, D.E. Crane, J.C. Stevens, and J.T. Walton. 2006b. Assessing Urban Forest Effects and Values: Minneapolis’ Urban Forest. Resource Bulletin NE U.S. Department of Agriculture, Forest Service, Northeastern Research Station, Newtown Square, PA. 20 pp. Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Produksi oksigen merupakan salah satu dari manfaat-manfaat lingkungan yang dihasilkan oleh pohon, dan pohon-pohon kota dapat menghasilkan sejumlah oksigen yang signifikan. Akan tetapi, apakah produksi oksigen ini mampu menciptakan manfaat lingkungan yang signifikan dibandingkan dnegan manfaat lingkungan lainnya, seperti penangkapan karbon dan penyerapan polusi udara? Di perkotaan Amerika Serikat, penangkapan karbon tahunan oleh hutan kota diestimasi sebesar 22.8 juta metric tons (25.1 juta tons) yang nilainya setara dengan ≈$460 juta per tahun (Nowak dan Crane, 2002). Penyerapan polusi udara di perkotaan Amerika Serikat diestimasi sebesar 711,000 metric tons (784,000 tons) yang nilainya setara $3.8 milyar setahun (Nowak et al., 2006a). 1.Nowak, D.J., and D.E. Crane Carbon storage and sequestration by urban trees in the USA. Environmental Pollution 116:381– Nowak, D.J., D.E. Crane, and J.C. Stevens. 2006a. Air pollution removal by urban trees and shrubs in the United States. Urban Forestry and Urban Greening 4:115–123. Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Pohon kota dapat memperbaiki kualitas udara kota (Cardelino dan Chameides 1990; Taha 1996; Nowak et al., 2000, 2006a). Perubahan kecil pada kandungan polutan udara dapat berdampak besar terhadap kualitas udara dan kesehatan manusia, sehingga efek-efek hutan kota terhadap polusi udara sangat besar. Badan perlindungan lingkungan di Amerika Serikat (U.S. Environmental Protection Agency) telah menyatakan bahwa tutupan pohon kota menjadi sarana potensial untuk membantu memperbaiki kualitas kualitas udara kota sesuai dnegan baku mutu udara kota (U.S. Environmental Protection Agency 2004; Nowak, 2005). 1.Cardelino, C.A., and W.L. Chameides Natural hydrocarbons, urbanization, and urban ozone. Journal of Geophysical Research 95:13971– Nowak, D.J., K.L. Civerolo, S.T. Rao, G. Sistla, C.J. Luley, and D.E. Crane A modeling study of the impact of urban trees on ozone. Atmospheric Environment 34: 1610– Nowak, D.J., D.E. Crane, and J.C. Stevens. 2006a. Air pollution removal by urban trees and shrubs in the United States. Urban Forestry and Urban Greening 4:115– Nowak,D.J Strategic tree planting as an EPA encouraged pollutant reduction strategy: How urban trees can obtain credit in State Implementation Plans. Sylvan Communities. Summer/Fall:23–27. 5.Taha, H Modeling impacts of increased urban vegetation on ozone air quality in the South Coast Air Basin. Atmospheric Environment 30:3423– U.S. Environmental Protection Agency Incorporating Emerging and Voluntary Measures in a State Implementation Plan (SIP). U.S. Environmental Protection Agency, Research Triangle Park, NC. oarpg/t1/memoranda/evm_ievm_g.pdfhttp://www.epa.gov/ttn/ Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Secara umum, pengaruh pohon-pohon terhadap polutan kimia mikro dalam atmosfir (bahan kimia yang merupakan komponen mikro dari keseluruhan atmosfir) akan mempunyai dampak relatif jauh lebih besar terhadap kualitas lingkungan dan kesehatan manusia, dibandingkan dengan bahan kimia seperti oksigen yang jumlahnya snagat besar dalam atmosfir. Perubahan yang relatif kecil pada polutan kimia mikro mempunyai dampak signifikan terhadap kesehatan lingkungan dan kesehatan manusia (misalnya dampak ozone, materi partikulat, oksida nitrogen, dan oksida belerang) dan perubahan iklim (misalnya dampak CO2). Nowak,D.J., R. Hoehn dan D.E. Crane Oxygen Production by Urban Trees in the United States. Arboriculture and Urban Forestry, 33(3):220–226.
Drought and Oxidative Load in the Leaves of C 3 Plants: a Predominant Role for Photorespiration?. Ann Bot (2002) 89 (7): G. NOCTOR, S. VELJOVIC‐JOVANOVIC, S. DRISCOLL, L. NOVITSKAYA and C.H. FOYER Although active oxygen species are produced at high rates in both the chloroplasts and peroxisomes of the leaves of C 3 plants, most attention has focused on the potentially damaging consequences of enhanced chloroplastic production in stress conditions such as drought. This article attempts to provide quantitative estimates of the relative contributions of the chloroplast electron transport chain and the glycolate oxidase reaction to the oxidative load placed on the photosynthetic leaf cell. Rates of photorespiratory H 2 O 2 production were obtained from photosynthetic and photorespiratory flux rates, derived from steady‐state leaf gas exchange measurements at varying irradiance and ambient CO 2. Assuming a 10 % allocation of photosynthetic electron flow to the Mehler reaction, photorespiratory H 2 O 2 production would account for about 70 % of total H 2 O 2 formed at all irradiances measured. When chloroplastic CO 2 concentration rates are decreased, photorespiration becomes even more predominant in H 2 O 2 generation. At the increased flux through photorespiration observed at lower ambient CO 2, the Mehler reaction would have to account for more than 35 % of the total photosynthetic electron flow in order to match the rate of peroxisomal H 2 O 2 production. The potential signalling role of H 2 O 2 produced in the peroxisomes is emphasized, and it is demonstrated that photorespiratory H 2 O 2 can perturb the redox states of leaf antioxidant pools. We discuss the interactions between oxidants, antioxidants and redox changes leading to modified gene expression, particularly in relation to drought, and call attention to the potential significance of photorespiratory H 2 O 2 in signalling and acclimation.
Satoo, T Notes on Kittredge’s method of estimation of amount of leaves of forest stand. Japan Forestry Soc., Vol. 44, Satoo, T Production and distribution of dry matter in forest ecosystems.Tokio Univ. Forests., № 16, Ada tiga metode yang terkenal untuk menduga biomasa tanaman (tegakan) hidup, yaitu (Satoo, 1962; Satoo, 1966): 1.Metode rata-rata pohon, tidak cukup akurat, terutama untuk menilai biomasa tahuj pohon, karena rata-rata pohon menurut diameternya ternyata tidak sama dengan rata-rata pohon menurut indeks-indeks lainnya; 2.Metode hubungan luas-dasar pohon-model dengan populasi pohon, yang lebih akurat dibandingkan dnegan metode (no 1), karena dilakukan pemilihan yang hati-hati pohon-model menurut diameter dan tinggi batang; panjang, kerapatan dan diameter tajuk; 3.Metode Regresi, dianggap paling universal dan akurat. Pohon-model (pohon sampel) dipilih sedemikian rupa sehingga dapat mewakili populasi pohon menurut diameter batangnya, dan tinggi pohon.
. Atroschenko, O.A Geographical information systems in forestry. Naukovyvisnyk NAU, № 20, Kyiv. Existing methodologies for assessing phytomass components of trees and stands are possible to separate by approaches: 1.Weight method involves weighing tree phytomass fractions in the forest and taking samples for determining moisture content; 2.Stereometric method includes measuring volumetric indices of stem and branches with further re-calculation to mass units using indices of wood and bark density; 3.Complex method combines weight and stereometric methods; 4.Pipe-model method is based on estimating components of tree crown phytomass based on theories of balanced system of xylem water transport of plants; 5.Aerospace methods aim on finding stochastic relations between decoded tree and stand indices and corresponding phytomass parameters; 6.Method of generalization rests upon analyzing published studies for different regions and deriving needed normative for assessing separate fractions of phytomass and bioproductivity of stands; 7.Use of GIS-systems and technologies is a rather new and high-technology method which is based upon use of modern findings in the sphere of information technologies and GIS- systems (Atroschenko, 1999).
Heinrich, D. and M. Hergt Dtv-Atlas Ecology. 4 Haulage, Mekanisme untuk menjaga stabilitas relatif suhu udara di bumi adalah radiasi matahari dan efek rumah kaca. Sekitar 30% energi matahari (gelombang pendek) yang mencapai bumu dipantulkan kembali ke ruang angkasa. Kalau energi sisanya (sekitar 70%), yang diserap sebagai radiasi infra-merah oleh uap air, awan dan tanah, dipantulkan kembali ke ruang angkasa, maka suhu bumi akan sema dnegan -18 °С. Refleksi radiasi infra-merah oleh bumi (terutama oleh uap air dan gas rumah kaca) memanaskannya hingga sekitar 15 °С (ΔT = 33 °С). Komposisi bahan kimia berikut mempunyhai efek pemanasan udara atmosfir : 1.Uap air ( sebesar 62%, 20,6°С); 2.Karbon dioxide (sebesar 21,8%, 7,2°С); 3.Ozone (sebesar 7,3%, 2,4°С); 4.Nitrous oxide (sebesar 4,2%, 1,4°С); 5.Methane (sebesar 2,4%, 0,8°С); 6.Fluoro-chloro-carbons (sebesar 2,1%, 0,7°С) (Heinrich dan Hergt, 1998).
1.Pasternak, V.P Productivity control in artificial spruce stands of Carpathian mountains. Kyiv. 2.Lakyda, P.I Growth and productivity models for artificial pine stands of Polesye of USSR. Kyiv. 3.Lishchuk M.E Growth and productivity of stands of softwood broadleaved tree species in Ukrainian Polissya.Kharkiv. Transformasi data dilakukan berdasarkan derivasi rata-rata tinggi pohon dari tinggi maksimum yang diketahui dengan model regresi: Pohon Norway spruce (Pasternak, 1990): Untuk Pohon Scots pine (Lakyda, 1986): Untuk pohon Birch (Lishchuk, 1988): dimana : Н – rata-rata tinggi suatu populasi tegakan; Ht – tinggi maksimum populasi tegakan; А – umur populasi tegakan.
Lakyda, P.I Productivity of forest stands of Ukraine by components of aboveground phytomass. Thesis (specialty “Forest inventory and forest mensuration”. Kyiv. Penangkapan karbon dan produksi oksigen dari hutan kota berkaitan erat dengan produksi biomasa melalui fotosintesis. Perhitungan penangkapan karbon dan produksi oksigen didasarkan pada analisis data biomasa tanaman. Oleh karena itu diperlukan deskripsi algoritma estimasi biomasa tegakan hutan dan karbon yang disimpan. Algoritma ini telah diimplementasikan oleh Lakyda (1997) dalam Paket Program CARBON (Lakyda, 1997).
1.Lakida, P Forest phytomass estimation for Ukraine / WP – Laxenburg, IIASA. 2.Lakida, P., Nilsson, S., Shvidenko, A Estimation of forest phytomass for selected countries of the former European USSR / WP – Laxenburg, IIASA. 3.Lakida, P., Nilsson, S., Shvidenko, A Forest Phytomass and Carbon in European Russia / WP –Laxenburg, IIASA. 4.Lakyda, P.I Productivity of forest stands of Ukraine by components of aboveground phytomass: abstract of Dr. Hab. Thesis (specialty “Forest inventory and forest mensuration”. Kyiv. The most adequate way to estimate phytomass and carbon sequestration of forests is to use large scale data of standing stock and mathematical models. Practical realization of this approach is tightly connected with finding coupling coefficients of phytomass components and stem wood volume based upon experimental data, which characterizes bioproductivity of modal forest stands (Lakyda, 1997). Calculation of conversion coefficients of phytomass fractions to standing stock of forest stands is shown below (Lakida, 1996; Lakida et al., 1995; Lakida et al., 1996): Rv=Mfr/Vst where : Rv– conversion coefficient of fraction of stand phytomass (leaves, branches, rootsetc.) to volume of stemwood, tons per cubicmeter; Mfr – mass of certain fraction of stand phytomass, tons; Vst – volume of stand stemwood over bark, m3.
Lakyda, P.I Productivity of forest stands of Ukraine by components of aboveground phytomass: abstract of Dr. Hab. Thesis (specialty “Forest inventory and forest mensuration”. Kyiv.. From this relation it was possible to estimate the fraction of stemwood over bark: Rv = Pst, where : Rv signifies base density of each phytomass component. This gave the possibility to control authenticity of sample data used for calculation of conversion coefficients. Practical application of Rv in the process of calculating phytomass components of forest stands is expressed in following equation: Mfr = Vst·Rv.
Further estimation of overall phytomass of stands was accompanied with calculation of conversion coefficients Rv for stand phytomass components listed below (Lakyda, 1997): Rv(f) – leaves (needles); Rv(br) – branches (wood and bark of crown branches); Rv(st) – stems (wood and bark of stems); Rv(ab) – above ground phytomass of a stand; Rv(bl) – below ground phytomass of a stand; Rv(us)–phytomass of an understorey (undergrowth, understorey (underwood), vegetation and their root systems). Overal stand phytomass Rv(tot)is calculated as a sum of listed components. Lakyda, P.I Productivity of forest stands of Ukraine by components of aboveground phytomass: abstract of Dr. Hab. Thesis (specialty “Forest inventory and forest mensuration”. Kyiv..
Finding analytical relations of change in Rv coefficients, implemented in the CARBON programme, of main phytomass components and mensurational indices of stands was done for every tree species using multiple regression method. Stand age (A), average height (H), average diameter (D), site index class (bonity index, B) and relative stand density (P) were considered as independent variables. Stand age and site index class were assumed to be main independent variables in Rv models. Three kinds of allometric relations were used for modeling Rv coefficients: Rv=b0Ab1Bb2exp(b3A),(6) Rv= b0Ab1Bb2,(7) Rv= b0Ab1,(8) where : А– average stand age, years; В – site index class code; b0, b1, b2, b3 – regression coefficients. Lakyda, P.I Productivity of forest stands of Ukraine by components of aboveground phytomass: abstract of Dr. Hab. Thesis (specialty “Forest inventory and forest mensuration”. Kyiv..
. Plant Physiol. Aug 2005; 138(4): 2292–2298. Fractionation of the Three Stable Oxygen Isotopes by Oxygen-Producing and Oxygen- Consuming Reactions in Photosynthetic Organisms. Yael HelmanYael Helman, Eugeni Barkan, Doron Eisenstadt, Boaz Luz, and Aaron Kaplan Eugeni BarkanDoron EisenstadtBoaz Luz The triple isotope composition (δ 17 O and δ 18 O) of dissolved O 2 in the ocean and in ice cores was recently used to assess the primary productivity over broad spatial and temporal scales. However, assessment of the productivity with the aid of this method must rely on accurate measurements of the 17 O/ 16 O versus 18 O/ 16 O relationship in each of the main oxygen-producing and -consuming reactions. Data obtained here showed that cleavage of water in photosystem II did not fractionate oxygen isotopes; the δ 18 O and δ 17 O of the O 2 evolved were essentially identical to those of the substrate water. The fractionation slopes for the oxygenase reaction of Rubisco and respiration were identical (0.518 ± 0.001) and that of glycolate oxidation was ± There was a considerable difference in the slopes of O 2 photoreduction (the Mehler reaction) in the cyanobacterium Synechocystis sp. strain PCC 6803 (0.497 ± 0.004) and that of pea (Pisum sativum) thylakoids (0.526 ± 0.001). These values provided clear and independent evidence that the mechanism of O 2 photoreduction differs between higher plants and cyanobacteria. We used our method to assess the magnitude of O 2 photoreduction in cyanobacterial cells maintained under conditions where photorespiration was negligible. It was found that electron flow to O 2 can be as high as 40% that leaving photosystem II, whereas respiratory activity in the light is only 6%. The implications of our findings to the evaluation of specific O 2 -producing or -consuming reactions, in vivo, are discussed.
Function of Carbon Sequestration and Oxygen Release of Rubber Plantations and Its Value Estimation. Jiang Jusheng, Wang Rusong Acta Ecologica SinicaActa Ecologica Sinica [2002, 22(9): ] Rubber trees can not only produce rubber and high quality wood but also provide significant ecological service that has been neglected for a long time. The ecological service and its value of the rubber plantations were studied. The carbon sequestration in the rubber tree was determined by means of biomass of mean rubber tree, and the oxygen release was then derived based on the photosynthesis. The results showed that the carbon sequestration from the atmosphere totaled 4.11 million tones/year and that the oxygen release totaled 2.99 million tones/year. THe values of the CO_2 and O_2 were estimated RMB billion yuan and RMB1.20 billion yuan when calculated by using the methods of the carbon tax and the cost of oxygen production respectively. The sum of the values was 28.7 times of that of their direct products (such as rubber, timber, etc). The CO_2 sequestration of the rubber plantations was 4.7 times of that of the tropical rainforest.photosynthesis The CO2 sequestration and O2 release of the rubber plantation in China has totaled million tones and 82.1 million tones respectively over the last 50 years, which has been playing important role in reducing the global green house effect.
Tahir,H.M.M dan T.A. Yousif Modeling the effect of Urban Trees on Atmospheric Oxygen Concentration in Khartoum State. Jour. of Nat. Res. and Env. Studies, 1 (2): Tahir dan Yousif (2013) melakukan penelitian efek pohon kota terhadap konsnetrasi oksigen udara Kota Khartoum. Konsnetrasi oksigen udara kota dicatat selama setahun. Pengukuran konsnetrasi oksigen secara spontan dilakukan secara simultan pada lahan terbuka kosong dan di bawah pohon pada ketinggian meter yang mencerminkan lingkungan hidupnya manusia. Analisis regresi linear menggunakan data konsnetrasi oksigen di bawah pohon sebagai peubah dependent dan konsentrasi oksigen di lahan terbuka sebagai peubah independent. Penelitian ini membuktikan bahwa kuantifikasi efek hutan kota terhadap konsnetrasi oksigen udara kota dapat diketahui dengan cukup akurat menggunakan model regresi empirik. Peningkatan konsentrasi oksigen udara kota di lokasi di bawah tegakan pohon kota berkisar antara 0.2% - 0.9% di smeua lokasi.
Trend graph for oxygen concentration (%) under the tree (O2sh) and in bare land (O2sun ) at Al Kadaru Modeling the effect of Urban Trees on Atmospheric Oxygen Concentration in Khartoum State. H.M. M. Tahir and T.A. Yousif JOURNAL OF NATURAL RESOURCES AND ENVIRONMENTAL STUDIES, 1 (2): 7-12.
Relationship between atmospheric oxygen concentration (%) under the trees (O2sh) and in bare land (O2sun ) in Khartoum state. Modeling the effect of Urban Trees on Atmospheric Oxygen Concentration in Khartoum State. H.M. M. Tahir and T.A. Yousif JOURNAL OF NATURAL RESOURCES AND ENVIRONMENTAL STUDIES, 1 (2): O2sun O2sh
Geochemical Journal, Vol. 38, pp. 77 to 88, 2004 Oxygen and carbon isotopic ratios of tree-ring cellulose in a conifer-hardwood mixed forest in northern Japan T. NAKATSUKA, K. OHNISHI, T. HARA, A. SUMIDA, D. MITSUISHI, N. KURITA and S.UEMURA Oxygen and carbon isotopic ratios (δ18O and δ13C) were analyzed for cellulose extracted from tree rings of 5 oak trees (Quercus crispula) and 4 fir trees (Abies sachalinensis) standing in a 1 ha plot of a sub-boreal conifer-hardwood mixed forest, northern Japan. The δ18O variations were well correlated between individual trees of Q. crispula (canopy trees) and A. sachalinensis (recently grown-up sub-canopy trees), although A. sachalinensis had about 1‰ higher δ18O values than Q. crispula on average and there was an apparent one-year phase lag between δ18O variations of the two species. The similar inter-annual variation in δ18O among different individuals and species suggests a common environmental control. Contrary to δ18O, the inter- annual variations in δ13C did not possess any common trends among individual trees for either Q. crispula or A. sachalinesis, suggesting that the ecological effects, such as spatial heterogeneities in δ13C and/or concentration of CO2 in canopy air and/or competition for light with neighboring trees, regulate the δ13C of photosynthetic products in each tree. Seasonal variations of the δ18O and δ13C within annual tree rings of Q. crispula showed random and cyclic characteristics, respectively. The difference between the annual patterns of δ 18O and δ13C supports the idea that δ18O is controlled by some environmental factors, which change from year to year, but δ13C is primarily governed by physiological conditions of the tree itself, which repeat regularly in every growing season.
Geochemical Journal, Vol. 38, pp. 77 to 88, 2004 Oxygen and carbon isotopic ratios of tree-ring cellulose in a conifer-hardwood mixed forest in northern Japan T. NAKATSUKA, K. OHNISHI, T. HARA, A. SUMIDA, D. MITSUISHI, N. KURITA and S.UEMURA The historical variation in of tree-ring cellulose in Q. crispula has negative correlations with those in both of winter and summer precipitation amounts, whereas it does not show any relationship with temperature, probably due to multiple source areas of water vapor for the precipitation at the studied area. Because the δ18O of precipitation in northern Japan is positively correlated with air temperature, the correlation between δ 18O and winter precipitation suggests that, in a year of heavy snowfall, the soil in this forest retains larger amount of lower δ18O water derived from snowmelt, which is taken by roots of Q. crispula in summer. On the other hand, the negative correlation with summer precipitation cannot be elucidated by the δ18O of rainfall, but must be explained by a higher relative humidity in the growing season in a year of larger summer rainfall. Our results confirm the potential of δ18O of tree-ring cellulose to reconstruct past climate in a forest with a heavy snowfall, and suggest the importance of the hydrological knowledge in an atmosphere-soil-plant system for the utilization of treering δ18O in paleoenvironmental purposes.
. The influence of vegetation activity on the Dole effect and its implications for changes in biospheric productivity in the mid-Holocene. Proc. R. Soc. Lond. B 22 March 1999 vol. 266 no D. J. Beerling The Dole effect is defined as the difference between the oxygen isotope composition of atmospheric oxygen and seawater (currently 23.5 parts per thousand) and reflects the balance between processes and fractionations associated with O 2 consumption and production by the terrestrial and marine biospheres. Isotopic records from ice cores and ocean sediments provide a means of assessing variations in the Dole effect during the late Quaternary but the biogeochemical interpretation of these changes is limited because we are currently unable to account adequately for vegetation effects on the global isotopic balance of atmospheric O 2. Here, I show that the previously unquantified influence of canopy transpiration on the isotopic composition of atmospheric water vapour now closes the mass balance budget for the isotopes of atmospheric O 2 under the current climate. Using this new finding, the effects of vegetation on the Dole effect have been assessed at the global scale for the mid–Holocene (6000 years ago). The results indicate that the small reduction in the Dole effect in the mid–Holocene represented a fall in the ratio of terrestrial to marine gross primary production from 1.8 to 1.0. Improved understanding of the environmental and physiological processes controlling the oxygen isotopic composition of plants and their feedback on the isotopes of atmospheric O 2 offers considerable promise in quantitatively accounting for the changes in biospheric productivity associated with the Dole effect over glacial–interglacial cycles. In addition, such work should provide an as yet unexploited basis for testing the results of climate models against the oxygen isotope composition of Quaternary plant fossils.
How many trees are needed to provide enough oxygen for one person? Luis Villazon, Thursday 23rd August Trees release oxygen when they use energy from sunlight to make glucose from carbon dioxide and water. Like all plants, trees also use oxygen when they split glucose back down to release energy to power their metabolisms. Averaged over a 24-hour period, they produce more oxygen than they use up; otherwise there would be no net gain in growth. It takes six molecules of CO2 to produce one molecule of glucose by photosynthesis, and six molecules of oxygen are released as a by-product. A glucose molecule contains six carbon atoms, so that’s a net gain of one molecule of oxygen for every atom of carbon added to the tree. A mature sycamore tree might be around 12m tall and weigh two tonnes, including the roots and leaves. If it grows by five per cent each year, it will produce around 100kg of wood, of which 38kg will be carbon. Allowing for the relative molecular weights of oxygen and carbon, this equates to 100kg of oxygen per tree per year. A human breathes about 9.5 tonnes of air in a year, but oxygen only makes up about 23 percent of that air, by mass, and we only extract a little over a third of the oxygen from each breath. That works out to a total of about 740kg of oxygen per year.
. Tree Facts Carbon sequestration, air quality, and climate change 1.A tree can absorb as much as 48 pounds of carbon dioxide per year, and can sequester one ton of carbon dioxide by the time it reaches 40 years old. 2.One large tree can provide a supply of oxygen for two people. Energy 1.According to the USDA Forest Service, “Trees properly placed around buildings can reduce air conditioning needs by 30 percent and save percent in energy used for heating.” 2.The net cooling effect of a young, healthy tree is equivalent to ten room-size air conditioners operating 20 hours a day.
. Tree Facts Water 1.In one day, one large tree can lift up to 100 gallons of water out of the ground and discharge it into the air. 2.For every five percent of tree cover added to a community, stormwater runoff is reduced by approximately two percent. Recreation and Wildlife 1.Healthy trees provide wildlife habitat and contribute to the social and economic well-being of landowners and community residents.
. Tree Facts EPA Urban Heat Island Effects 1.Reduced energy use: Trees and vegetation that directly shade buildings decrease demand for air conditioning. 2.Improved air quality and lower greenhouse gas emissions: By reducing energy demand, trees and vegetation decrease the production of associated air pollution and greenhouse gas emissions. They also remove air pollutants and store and sequester carbon dioxide. 3.Enhanced storm water management and water quality: Vegetation reduces runoff and improves water quality by absorbing and filtering rainwater. 4.Reduced pavement maintenance: Tree shade can slow deterioration of street pavement, decreasing the amount of maintenance needed. 5.Improved quality of life: Trees and vegetation provide aesthetic value, habitat for many species, and can reduce noise
The Effect of Temperature on the Rate of Photosynthesis By Bob Barber, eHow Contributor, last updated April 17, 2014 Read more: photosynthesis.html#ixzz3qGsExmtnhttp://www.ehow.com/about_ _effect-temperature-rate- photosynthesis.html#ixzz3qGsExmtn Plants produce sugar and oxygen from carbon dioxide, water and sunlight. This process is called photosynthesis. Photosynthesis is a series of chemical reactions. Heat speeds up chemical reactions by adding kinetic energy to the reactants. Therefore, heat speeds up photosynthesis, unless another factor, such as weak light, limits photosynthesis. However, there is a wild card. Too much heat destroys enzymes-- complex proteins which greatly increase the rate of photosynthesis. So heat speeds up photosynthesis---to a point. Once heat begins to destroy enzymes, photosynthesis drastically slows. Read more: photosynthesis.html#ixzz3qGs8SjGHhttp://www.ehow.com/about_ _effect-temperature-rate- photosynthesis.html#ixzz3qGs8SjGH
. _temperature_and_light_graph_(pl).png, Jiří Janoušek original image author, image modified by Bob Barber, English text, explanations added Read more: photosynthesis.html#ixzz3qGsa3mZ0http://www.ehow.com/about_ _effect-temperature-rate- photosynthesis.html#ixzz3qGsa3mZ0 X
. Source of Oxygen Formed by Photosynthesis By Jennifer Sobek, eHow Contributor Read more: photosynthesis.html#ixzz3qGrpbDrjhttp://www.ehow.com/info_ _source-oxygen-formed- photosynthesis.html#ixzz3qGrpbDrj Photosynthesis is the process that plants and some bacteria undergo by using the energy from the sun to make sugar and oxygen. The glucose is further converted into ATP (adenosine triphosphate), or the energy that is used for all living things. The oxygen formed by photosynthesis comes from the water that is introduced through the plant's roots. The elements involved in photosynthesis are sunlight, water and carbon dioxide. The water enters the plant through its roots and the carbon dioxide gets into the plant through small openings in the leaves called stomata. The photosynthetic reaction takes place within the chloroplasts in the leaves. A chloroplast is the food producer of the cell and can only be found in plant cells. Chloroplasts contain the green pigment called chlorophyll, which gives a leaf its color.
According to Dr. Mike Farabee, of Estrella Mountain Community College, the chemical equation for the photosynthetic reaction that takes place is expressed as 6H2O + 6CO2 --> C6H12O6 + 6O2. Oxygen and glucose are the products of photosynthesis, while water and carbon dioxide are the reactants. Once the water enters the root, it travels up to the leaves through the plant cells called xylem. Carbon dioxide isn't able to negotiate through the waxy layer that covers the leaf, but it gets in through the stomata. By the same token, the oxygen that is produced during photosynthesis leaves the leaf through the same stomata For photosynthesis to occur, there must be sunlight. Without sunlight, there won't be that energy that the chloroplasts need to stimulate the electrons. The series of reactions that take place converts the energy into ATP and NADPH (a substance that helps in the production of carbohydrates). The NADPH comes from the introduction of carbon dioxide into the equation. A living organism isn't able to directly use the light energy, but converts it into a C-C bond (a covalent carbon bond) through a series of reactions. Source of Oxygen Formed by Photosynthesis By Jennifer Sobek, eHow Contributor Read more: photosynthesis.html#ixzz3qGrpbDrjhttp://www.ehow.com/info_ _source-oxygen-formed- photosynthesis.html#ixzz3qGrpbDrj
Zhang, X., Zhou, P., Zhang, W., Zhang, W. dan Y.Wang. (2013). Selection of Landscape Tree Species of Tolerant to Sulfur Dioxide Pollution in Subtropical China. Open Journal of Forestry, 3, Sulfur dioxide (SO 2 ) is a major air pollutant, especially in developing countries. Many trees are seriously impaired by SO 2, while other species can mitigate air pollution by absorbing this gas. Planting appropriate tree species near industrial complexes is critical for aesthetic value and pollution mitigation. In this study, six landscape tree species typical of a subtropical area were investigated for their tolerance of SO 2 : Cinnamomum camphora (L.) J. Presl., Ilex rotunda Thunb., Lysidice rhodostegia Hance, Ceiba insignis (Kunth) P. E. Gibbs & Semir, Cassia surattensis Burm. f., and Michelia chapensis Dandy. We measured net photosynthesis rate, stomatal conductance, leaf sulfur content, relative water content, relative proline content, and other parameters under 1.31 mg·m -3 SO 2 fumigation for eight days. The results revealed that the six species differed in their biochemical characteristics under SO 2 stress. Based on these data, the most appropriate species for planting in SO 2 polluted areas was I. rotunda, because it grew normally under SO 2 stress and could absorb SO 2.
F. Ramdani, "Extraction of Urban Vegetation in Highly Dense Urban Environment with Application to Measure Inhabitants’ Satisfaction of Urban Green Space," Journal of Geographic Information System, Vol. 5 No. 2, 2013, pp doi: /jgis /jgis Urban environment has functioned not only for ecological reason but also for socioeconomic function, due to this reason extraction of urban vegetation in highly dense urban environment becomes more important to understand the inhabitants’ satisfaction of urban green space. With a medium resolution of satellite imagery, the precision is very low. We used high resolution of WorldView-2 satellite to raise the accuracy. We chose Depok City in West Java as a case study area, analyse four multispectral bands, and apply TCT algorithm for getting vegetation density. The relationship between vegetation density and inhabitants’ satisfaction was calculated by Geo-statistical technique based on administrative boundary. We extracted three types of urban vegetation density: good, mid and low. The final result shows that the inhabitants are mostly satisfied with good density of urban vegetation in the city forest inside Campus University of Indonesia.
D.J. NOWAK, R. E. HOEHN III, D.E. CRANE, J.C. STEVENS, dan C.L.FISHER Assessing Urban Forest Effects and Values. Chicago Urban Forest USDA FOREST SERVICE, 11 CAMPUS BLVD SUITE 200, NEWTOWN SQUARE PA An analysis of trees in Chicago, IL, reveals that this city has about 3,585,000 trees with canopies that cover 17.2 percent of the area. The most common tree species are white ash, mulberry species, green ash, and tree-of-heaven. Chicago’s urban forest currently stores about 716,000 tons of carbon valued at $14.8 million. In addition, these trees remove about 25,200 tons of carbon per year ($521,000 per year) and about 888 tons of air pollution per year ($6.4 million per year). Trees in Chicago are estimated to reduce annual residential energy costs by $360,000 per year. The structural, or compensatory, value is estimated at $2.3 billion. Information on the structure and functions of the urban forest can be used to inform urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Chicago area.
Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa Penyerapan polusi udara oleh pohon-pohon kota di Chicago diestimasi dnegan menggunakan Model UFORE dengan data lapangan dan data polusi jam-jaman, dat data cuaca selama tahun 2000 (Nowak et al., 2010). Penyerapan polutan udara paling besar adalah ozone (O3), diikuti oleh materi partikulat di bawah 10 microns (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), dan karbon monoxide (CO). Pohon diestimasi mampu menyerap 888 ton polutan udara (CO, NO2, O3, PM10, SO2) setiap tahun dnegan nilai setara dengan $6.4 juta.
Rata-rata persentasi penyerapan polusi udara selama siang hari, pada musim pohon berdaun lebah diestimasi sebesar: O3 0.45% PM % SO2 0.44% NO2 0.27% CO 0.002% Perbaikan kualitas lingkungan “Peak 1-hour” selama musim berdaun untuk daerah-daerah yang banyak pohonnya, diestimasi sebesar: O3 13.4% PM10 9.9% SO2 14.1% NO2 6.3% CO 0.05% Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa
Penangkapan dan Simpanan Karbon Climate change is an issue of global concern. Urban trees can help mitigate climate change by sequestering atmospheric carbon (from carbon dioxide) in tissue and by reducing energy use in buildings, and consequently reducing carbon dioxide emissions from fossil-fuel based power plants. Trees reduce the amount of carbon in the atmosphere by sequestering carbon in new tissue growth every year. The amount of carbon annually sequestered is increased with healthier trees and larger diameter trees. Gross sequestration by trees in Chicago is about 25,200 tons of carbon per year with an associated value of $521,000. Net carbon sequestration in the Chicago urban forest is estimated at about 17,700 tons. Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa
Carbon storage by trees is another way trees can infl uence global climate change. As trees grow, they store more carbon by holding it in their accumulated tissue. As trees die and decay, they release much of the stored carbon back to the atmosphere. Thus, carbon storage is an indication of the amount of carbon that can be released if trees are allowed to die and decompose. Maintaining healthy trees will keep the carbon stored in trees and when trees die, utilizing the wood in long-term wood products or to help heat buildings or produce energy will help reduce carbon emissions from wood decomposition or from power plants. Trees in Chicago are estimated to store 716,000 tons of carbon ($14.8 million). Of all the species sampled, silver maple stores and sequesters the most carbon (approximately 14.8% of the total carbon stored and 10.7% of all sequestered carbon). Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa
Trees Affect Energy Use in Buildings Trees affect energy consumption by shading buildings, providing evaporative cooling, and blocking winter winds. Trees tend to reduce building energy consumption in the summer months and can either increase or decrease building energy use in the winter months, depending on the location of trees around the building. Estimates of tree effects on energy use are based on fi eld measurements of tree distance and direction to space-conditioned residential buildings. Based on average state energy costs in February 2009, trees in Chicago are estimated to reduce energy costs from residential buildings by $360,000 annually. Trees are estimated to slightly increase the amount of carbon released by fossil-fuel based power plants. However, this estimated increase in emissions (1,200 tons) is more than offset by annual carbon sequestration by trees (25,200 tons). Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa
Urban vegetation can directly and indirectly affect local and regional air quality by altering the urban atmospheric environment. Four main ways that urban trees affect air quality are: 1.Temperature reduction and other microclimatic effects 2.Removal of air pollutants 3.Emission of volatile organic compounds (VOC) and tree maintenance emissions 4.Energy conservation in buildings and consequent power plant emissions The cumulative and interactive effects of trees on climate, pollution removal, and VOC and power plant emissions determine the overall impact of trees on air pollution. Cumulative studies involving urban tree impacts on ozone have revealed that increased urban canopy cover, particularly with low VOC emitting species, leads to reduced ozone concentrations in cities. Local urban forest management decisions also can help improve air quality. Nowak,D.J., R. E. Hoehn, D.E. Crane, J.C. Stevens dan C.L.Fisher Assessing urban forest effects and values. Usda forest service, 11 campus blvd suite 200, newtown square pa
. D.J. NOWAK, R. E. HOEHN III, D.E. CRANE, J.C. STEVENS, dan C.L.FISHER Assessing Urban Forest Effects and Values. USDA FOREST SERVICE, 11 CAMPUS BLVD SUITE 200, NEWTOWN SQUARE PA Urban forest management strategies to help improve air quality include: StrategiAlasan-alasannya Increase the number of healthy treesPeningkatan penyerapan polutan Sustain existing tree coverMaintain pollution removal levels Maximize use of low VOC-emitting treesReduces ozone and carbon monoxide formation Sustain large, healthy treesLarge trees have greatest per-tree effects Use long-lived treesReduce long-term pollutant emissions from planting and removal Use low maintenance treesReduce pollutants emissions from maintenance activities Reduce fossil fuel use in maintaining vegetationReduce pollutant emissions Plant trees in energy conserving locationsReduce pollutant emissions from power plants Plant trees to shade parked carsReduce vehicular VOC emissions Supply ample water to vegetationEnhance pollution removal and temperature reduction Plant trees in polluted or heavily populated areasMaximizes tree air quality benefi ts Avoid pollutant-sensitive speciesImprove tree health Utilize evergreen trees for particulate matterYear-round removal of particles
J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5): With effective planning and management, urban trees and forests will provide a wide range of important benefits to urbanites. These include a more pleasant, healthful, and comfortable environment to live, work, and play in, savings in the costs of providing a wide range of urban services, and substantial improvements in individual and community wellbeing. Urban forestry plans should begin with consideration of the contribution that trees and forests can make to people's needs. Planning and management efforts should focus on how the forest can best meet those needs. Past planning and management efforts have not been as effective as they might have been because planners and managers have underestimated the potential benefits that urban trees and forests can provide, and have not understood the planning and management efforts needed to provide those benefits, particularly the linkages between benefits and characteristics of the urban forest and its management.
Physical/Biological Environment and Processes Urban and community forests can strongly influence the physical/biological environment and mitigate many impacts of urban development by moderating climate, conserving energy, carbon dioxide, and water, improving air quality, controlling rainfall runoff and flooding, lowering noise levels, harboring wildlife, and enhancing the attractiveness of cities. These benefits may be partially offset by problems that vegetation can pose such as pollen production, hydrocarbon emissions, green waste disposal, water consumption, and displacement of native species by aggressive exotics. Urban forests can be viewed as a "living technology," a key component of the urban infrastructure that helps maintain a healthy environment for urban dwellers. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Air quality. Trees exchange gases with the atmosphere and capture particulates that can be harmful to people. The rate at which trees remove gaseous pollutants such as ozone, carbon monoxide, and sulphur dioxide depends primarily on the amount of foliage, number and condition of the stomata, and meteorological conditions. Results from computer studies indicate that trees can reduce appreciably the amount of ozone in polluted air. Pine trees in Los Angeles were projected to remove from the atmosphere (under 400 meters) about 8% of the ozone and decrease the concentration around the leaves by 49% (Rich, 1971). 1.Rich, S Effects of trees and forests in reducing air pollution, pp In Little, S and J.H. Noyes (eds) Trees and Forests in an Urbanizing Environment. USDA Cooperative Extension Service, University of Massachusetts, Amherst. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Urban hydrology. Urban forests can play an important role in urban hydrologic processes by reducing the rate and volume of stormwater runoff, flooding damage, stormwater treatment costs, and water quality problems. Runoff estimates for an intensive storm event in Dayton, Ohio showed that the existing tree canopy reduced potential runoff by 7% and a modest increase in canopy cover would reduce runoff by nearly 12% (Sanders, 1984). Runoff reductions could be further enhanced by directing runoff to landscape plantings. 1.Sanders, R.A Urban vegetation impacts on the urban hydrology of Dayton Ohio. Urban Ecol. 9: J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
URBAN HYDROLOGY By reducing runoff, trees function like retention/ detention structures that are essential to many communities. Savings in stormwater management costs from trees in Tucson were calculated at $0.18 per tree per year or $600,000 over 500,000 trees and 40 years (McPherson, 1991). Reduced runoff due to rainfall interception can also reduce stormwater treatment costs in many communities. 1.McPherson, E.G Economic modeling for large scale tree plantings. In E. Vine, D. Crawley, and P. Centolella (Eds). Energy Efficiency and the Environment: Forging the Link, Chapter 19, American Council for an Energy-Efficient Economy, Washington DC. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
URBAN HYDROLOGY Water use by landscape vegetation is an important issue in arid and semi-arid regions where water resources are increasingly scarce; but also in other areas where drought can bring about restrictions on watering. We know that annual water costs can be twice as great as cooling energy savings from shade for high water use species such as mulberry (McPherson and Dougherty, 1989.). However, energy savings have the indirect effect of conserving water at power plants. In Tucson, 16% of the annual irrigation requirement for each tree was offset by water conserved at the power plant due to energy savings provided by the tree. 1.McPherson, E.G. and E. Dougherty Selecting trees for shade in the Southwest. J. Arboric. 15: J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Noise reduction. Field tests have shown that properly designed plantings of trees and shrubs significantly reduce noise. Wide belts of tall dense trees combined with soft ground surfaces can reduce apparent loudness by 50% or more (Cook, 1978; Reethof dan McDaniel, ) Noise reduction from plantings along roadsides in urbanized areas is often limited due to narrow roadside planting space. Buffer plantings in these circumstances are typically more effective at screening views than reducing noise. 1.Cook, D.I Trees, solid barriers, and combinations: Alternatives for noise control, pp In Hopkins, G. (ed.) Proceedings of the National Urban Forestry Conference, USDA Forest Service, State University of New York College of Environmental Science and Forestry, Syracuse, NY. 2.Reethof, G. and O.H. McDaniel Acoustics and the urban forest, pp In Hopkins, G. (ed.) Proceedings of the National Urban Forestry Conference, USDA Forest Service, State University of New York College of Environmental Science and Forestry, Syracuse, NY. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5): Ecological benefits. Urban forests promote ecological stability by providing habitat for wildlife, conserving soil, and enhancing biodiversity. Although the value of these benefits is seldom quantified, they are important to many urban dwellers and to the long term stability of urban ecosystems. Surveys have found that most citydwellers enjoy and appreciate wildlife in their day to day lives (Shaw, Magnum dan Lyons. 1985). 1.Shaw, W.W., Magnum, W.R., and J.R. Lyons Residential enjoyment of wildlife resources by Americans. Leis. Sci. 7:
J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5): Ecological benefits. To enhance wildlife habitat, numerous communities havedeveloped programs to preserve valuable existing natural areas and to restore the habitat on degraded lands. For example, restoration of urban riparian corridors and their linkages to surrounding natural areas have facilitated the movement of wildlife and dispersal of flora. Usually habitat creation and enhancement increases biodiversity and complements many other beneficial functions of the urban forest (Johnson, Barker dan Johnson, 1990). 1.Johnson, C.W., F.S.Barker and W.S. Johnson Urban and Community Forestry. USDA Forest Service, Ogden UT.
With effective planning and management, urban trees and forests will provide a wide range of important benefits to urbanites. These include a more pleasant, healthful, and comfortable environment in which to live, work, and play, savings in the costs of providing a wide range of urban services, and substantial improvements in individual and community well-being (Dwyer, et al., 1992).. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Urban forests can enhance the city environment by influencing temperature, wind, humidity, rainfall, soil erosion, flooding, air quality, scenic quality, and plant and animal diversity. Each of these influences has significant implications for the well-being of urbanites. But there are also environmental problems that may be associated with the urban forest, such as the generation of pollen, hydrocarbons, and green waste; water and energy consumption; obscured views; and displacement of native species of plants (Dwyer, et al., 1992).. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
A well planned and managed urban forest can reduce costs for heating and cooling, health care, driving to exurban areas for recreation and leisure, stormwater management, and damage from flooding, erosion, and polluted air. Substantial increases in revenues can also be associated with urban trees and forests, including the sale of real estate (individual gains), real estate and business taxes (government gains), and tourism (individuals and government may gain). Costs associated with urban forests include establishment and care of the forest; repair of forest-induced damage to other parts of the urban infrastructure (particularly sidewalks and utilities); blocked solar collectors, and foregone opportunities for activities such as gardening and sports (Dwyer, et al., 1992).. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Many important benefits and costs of urban forests that contribute significantly to the wellbeing of urbanites are not easily reflected in dollars and cents. Psychological benefits associated with urban forests include more pleasant environments for a wide range of activities, improvements in the esthetic environment (sights, sounds, smells), relief from stress (which can lead to improved physical health), enhanced feelings and moods, increased enjoyment of everyday life, and a stronger feeling of connection between people and their environment. Psychological costs can include fears of crime, animals, insects, disease (i.e., Lyme disease), darkness, and falling trees or limbs; and the displeasure of messiness and clutter (Dwyer, et al., 1992). J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Benefits attributed to urban trees and forests extend beyond individuals to society. Societal benefits include a stronger sense of community, empowerment to improve neighborhood conditions, promotion of environmental responsibility and ethics, and enhanced economic development (business, commerce, employment). Societal costs include money and other resources that must be diverted from other social programs (Dwyer, et al., 1992). J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Urban forestry plans should begin with consideration of the contribution that trees and forests can make to people's needs. Planning and management efforts should focus on how the forest can best meet those needs. Past planning and management efforts have not been as effective as they might have been because planners and managers have underestimated the potential benefits that urban trees and forests can provide, and have not understood the planning and management efforts needed to provide those benefits, particularly the linkages between benefits and characteristics of the urban forest and its management (Dwyer, et al., 1992).. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
Urban trees and forests promise to be even more consequential in the years ahead. Increasing interest in cost-effective and "minimum impact“ approaches for improving the quality of the urban environment suggests that trees will play increasingly important roles in efforts to enhance airquality and improve urban hydrologic processes. Worldwide concern for "global warming" suggests increasing interest in trees for sequestering carbon and reducing carbon dioxide emissions. Associated concern for efficient use of energy resources will bring increasing attention to trees as a means of reducing heating and cooling costs as well as for encouraging urbanites to spend leisure time in the urban environment rather than driving to more remote areas. As we learn more about the functioning of the urban ecosystem and the role of trees and forests in that system, it is likely that these resources will assume new roles in efforts to manage the urban environment. (Dwyer, et al., 1992).. J.F. Dwyer, E. G.McPherson, H.W. Schroeder, and R.A. Rowntree ASSESSING THE BENEFITS AND COSTS OF THE URBAN FOREST. Journal of Arboriculture 18(5):
T.ShakeelT.Shakeel and T.M. Conway, Individual households and their trees: Fine-scale characteristics shaping urban forest. Urban Forestry & Urban Greening 01/2014; 13(1): In urban areas, the pattern of trees is often a result of municipal policy, built form, neighborhood socioeconomic conditions, and the actions of local actors. Recent research has focused on the role of neighborhood socioeconomics, and begun to explore the underlying causes of uneven distributions of urban forests associated with different socioeconomic groups. To date, little work has explored property-level tree conditions in relation to disaggregated household characteristics and actions, yet the household is the scale where most decisions about residential tree planting and care are made. This study examines the role of property-level built conditions, household socioeconomics, and residents’ actions and attitudes in relation to property-level canopy cover and tree density. The study area is four neighborhoods in the City of Mississauga (ON, Canada). Regression analyses were conducted to explore significant variables related to the two tree measures for all properties together and separately by neighborhood. The results indicate that property conditions and residents actions are more important in relation to tree variations than socioeconomic factors. Additionally, several significant factors have opposite relationships with percent canopy cover and tree density. These results highlight the need to consider property-level built conditions, residents’ actions, and multiple measures of the urban forest to better understand the patterns of trees in cities.
. K.Perini, and A. Magliocco Effects of vegetation, urban density, building height, and atmospheric conditions on local temperatures and thermal comfort. Urban Forestry & Urban Greening 01/2014. K.Perini This paper shows the effects of several variables, which co-cause the Urban Heat Island effect on temperature distribution and outdoor thermal comfort (by using the Predicted Mean Vote, PMV) on dense urban environments. The study is conducted by means of a three-dimensional microclimate model, ENVI-met 3.1, which forecasts the microclimatic changes within urban environments. The effects of building density (% of built area) and canyon effect (building height) on potential temperature, mean radiant temperature, and Predicted Mean Vote distribution are quantified. The influence of several types of green areas (vegetation on the ground and on roofs) on temperature mitigation and on comfort improvements is investigated for different atmospheric conditions and latitudes in a Mediterranean climate. The research quantifies the effects of the variables investigated on temperature distributions and in determining outdoor comfort conditions. Vegetation on the ground and on roofs mitigates summer temperatures, decreases the indoor cooling load demand, and improves outdoor comfort. The results of the study demonstrate that density and height of buildings in a city area influence potential temperature, mean radiant temperature, and Predicted Mean Vote distribution; for most of the cases examined higher density causes higher temperatures and with taller buildings vegetation has higher cooling effects. Considering the cooling effect of vegetation, a difference can be noticed depending on the amount of green areas and vegetation type. The results of this study show also that vegetation is more effective with higher temperatures and lower relative humidity values in mitigating potential temperatures, mean radiant temperatures, and PMV and in decreasing the cooling load demand.
Jim, C.YJim, C.Y. and W.Y.Chen Ecosystem services and valuation of urban forests in China. Cities, 26 (4): Urban forests are integral components of urban ecosystems, which could generate significant ecosystem services, such as offsetting carbon emission, removing air pollutants, regulating the microclimate, and recreation. These ecosystem services contribute to improving environmental quality, quality of life, and sustainable urban development. Despite a long history of inserting vegetation in human settlements in China, modern scientific study of this natural-cum-cultural resource did not start until the 1990s. Specifically, the identification and valuation of ecosystem services provided by urban forests are relatively new but fast growing research fields. This paper reviews studies on the major ecosystem services provided by urban forests in China, including microclimatic amelioration (mainly evapotranspiration-cooling effects), carbon dioxide sequestration, oxygen generation, removal of gaseous and particulate pollutants, recreational and amenity. Various valuation techniques have been applied, most of which are still at the embryonic stage. There are rooms to improve the research scope and methods. Some pertinent research gaps and implications on current and future development of urban forestry in China were distilled from the research findings.
Lafortezza,R.R., C. G.Giuseppe, S.G.Giovanni and C.C.Davies Benefits and well-being perceived by people visiting green spaces in periods of heat stress. Urban Forestry and Urban Greening, 8 (2): In urban environments, green spaces have proven to act as ameliorating factors of some climatic features related to heat stress, reducing their effects and providing comfortable outdoor settings for people. In addition, green spaces have demonstrated greater capacity, compared with built-up areas, for promoting human health and well- being. In this paper, we present results of a study conducted in Italy and the UK with the general goal to contribute to the theoretical and empirical rationale for linking green spaces with well-being in urban environments. Specifically, the study focused on the physical and psychological benefits and the general well-being associated with the use of green spaces on people when heat stress episodes are more likely to occur. A questionnaire was set up and administered to users of selected green spaces in Italy and the UK (n=800). Results indicate that longer and frequent visits of green spaces generate significant improvements of the perceived benefits and well-being among users. These results are consistent with the idea that the use of green spaces could alleviate the perception of thermal discomfort during periods of heat stress
Helena, N., H.Terry, C.M.Hagerhall, L.A.G. Fry Components of small urban parks that predict the possibility for restoration. Urban Forestry and Urban Greening, 8 (4): In densifying cities, small green spaces such as pocket parks are likely to become more important as settings for restoration. Well-designed small parks may serve restoration well, but earlier research on restorative environments does not provide detailed information about the specific components of the physical environment that support restoration. In this study we assessed the extent to which hardscape, grass, lower ground vegetation, flowering plants, bushes, trees, water, and size predicted the judged possibility for restoration in small urban green spaces. We took individual parks as the units of analysis. The parks were sampled from Scandinavian cities, and each park was represented by a single photo. Each photo was quantified in terms of the different objective park components and also rated on psychological variables related to restoration. The ratings on the psychological variables being away, fascination, likelihood of restoration, and preference were provided by groups of people familiar with such parks. The variables most predictive of the likelihood of restoration were the percentage of ground surface covered by grass, the amount of trees and bushes visible from the given viewing point, and apparent park size. Formal mediation analyses indicated distinctive patterns of full and partial mediation of the relations between environmental components and restoration likelihood by being away and fascination. Our results provide guidance for the design of small yet restorative urban parks.
. Nagendra,H. and D.Gopal Street trees in Bangalore: Density, diversity, composition and distribution. Urban Forestry and Urban Greening, 9 (2): Once renowned as India's "garden city", the fast growing southern Indian city of Bangalore is rapidly losing tree cover in public spaces including on roads. This study aims to study the distribution of street trees in Bangalore, to assess differences in tree density, size and species composition across roads of different widths, and to investigate changes in planting practices over time. A spatially stratified approach was used for sampling with 152 transects of 200 m length distributed across wide roads (with a width of 24 m or greater), medium sized roads (12-24 m) and narrow roads (less than 12 m). We find the density of street trees in Bangalore to be lower than many other Asian cities. Species diversity is high, with the most dominant species accounting for less than 10% of the overall population. Narrow roads, usually in congested residential neighborhoods, have fewer trees, smaller sized tree species, and a lower species diversity compared to wide roads. Since wide roads are being felled of trees across the city for road widening, this implies that Bangalore's street tree population is being selectively denuded of its largest trees. Older trees have a more diverse distribution with several large sized species, while young trees come from a less diverse species set, largely dominated by small statured species with narrow canopies, which have a lower capacity to absorb atmospheric pollutants, mitigate urban heat island effects, stabilize soil, prevent ground water runoff, and sequester carbon. This has serious implications for the city's environmental and ecological health. These results highlight the need to protect large street trees on wide roads from tree felling, and to select an appropriate and diverse mix of large and small sized tree species for new planting
Hamada,S.S. and T. Ohta Seasonal variations in the cooling effect of urban green areas on surrounding urban areas. Urban Forestry and Urban Greening, 9 (1): We measured air temperature in an urban green area that includes forest and grassland and in the surrounding urban area for a full year in Nagoya, central Japan, to elucidate seasonal variations of the difference in air temperature between urban and green areas. We determined the range of the "cool-island" effect as well as the relationship between vegetation cover and air temperature throughout the year. The temperature difference between urban and green areas was large in summer and small in winter. The maximum air temperature difference was 1.9 °C in July 2007, and the minimum was -0.3 °C in March The difference was larger during the day than during the night in summer, whereas in winter the opposite relationship was true. However, winter diurnal variation was not particularly noticeable, a behaviour thought to be related to reduced shading by deciduous trees in the green area. During the night, the cooling effect of the green area reached m into the urban area. During the day, the cooling effect between August and October 2006 exceeded 300 m and varied widely, although there was no correlation beyond 500 m. The correlation between air temperature and forest-cover ratio within a radius of 200 m from each measurement site was significant from 16:00 to 19:00. There was also a correlation during the night; this correlation was weakest in the early morning. The effect of the forest-cover ratio on air temperature was most pronounced in August 2006 and June 2007.
Stoffberg, G. H., Van Rooyen, M.W.W., Van Der Linde, M.J., Groeneveld, T.H.T Carbon sequestration estimates of indigenous street trees in the City of Tshwane, South Africa. Urban Forestry and Urban Greening, 9 (1): Amelioration of global warming presents opportunities for urban forests to act as carbon sinks, and thereby could possibly be included in the potential future carbon trade industry. The City of Tshwane Metropolitan Municipality provided a strategy in 2002 to plant 115,200 indigenous street trees in the period These trees hold a monetary carbon value in their potential future growth. In order to calculate the carbon sequestration potential, the growth rates of Combretum erythrophyllum, Searsia lancea and Searsia pendulina were determined. Combined species growth regressions of C. erythrophyllum-S. lancea and S. lancea-S. pendulina are also presented. Combretum erythrophyllum has the fastest growth rate while those of S. lancea and S. pendulina are slower. The results from growth regression relationships were used in a generic allometric biomass regression to calculate the carbon sequestration rate of each species, which was extrapolated to determine the total quantity of carbon to be sequestrated by the street trees over a 30-year period ( ). It is estimated that the tree planting will result in 200,492 tonnes CO2 equivalent reduction and that 54,630 tonnes carbon will be sequestrated. The carbon dioxide reductions could be valued at more than US$ 3,000,000. But this estimate should also be viewed in the context of the limitations presented in this study. This illustrates that when future carbon trade becomes operational for urban forests these forests could become a valuable source of revenue for the urban forestry industry, especially in developing countries.
Onishi,A., Cao, X., Ito, T., Shi, F., and H.Imura Evaluating the potential for urban heat- island mitigation by greening parking lots. Urban Forestry and Urban Greening, 9 (4): Artificial urban land uses such as commercial and residential buildings, roads, and parking lots covered by impervious surfaces can contribute to the formation of urban heat islands (UHIs), whereas vegetation such as trees, grass, and shrubs can mitigate UHIs. Considering the increasing area of parking lots with little vegetation cover in Nagoya, Japan, this study evaluated the potential for UHI mitigation of greening parking lots in Nagoya. The relationships between land surface temperature (LST) and land use/land cover (LULC) in different seasons were analyzed using multivariate linear regression models. Potential UHI mitigation was then simulated for two scenarios: (1) grass is planted on the surface of each parking lot with coverage from 10 to 100% at an interval of 10% and (2) parking lots are covered by 30% trees and 70% grass. The results show that different LULC types play different roles in different seasons and times. On average, both scenarios slightly reduced the LST for the whole study area in spring or summer. However, for an individual parking lot, the maximum LST decrease was 7.26 °C in summer. This research can help us understand the roles of vegetation cover and provide practical guidelines for planning parking lots to mitigate UHIs
Lo, A. and C.Y.Jim Willingness of residents to pay and motives for conservation of urban green spaces in the compact city of Hong Kong. Urban Forestry and Urban Greening, 9 (2): People attach multiple values to urban green spaces which play varied roles in cities. Properly designed monetary valuation surveys can ascertain their non-market value and underlying motives. This study investigates Hong Kong residents' recreational use of urban green spaces and assesses the monetary value of these areas. A total of 495 urban residents from different neighbourhoods and socio-economic groups were interviewed. About 70% of the respondents visited urban green spaces at least weekly. Major companions during patronage were family members and then children. Exercises and clean air topped the list of visit purposes. The recreational pattern is associated with the cramped private living condition that pushes people to public open areas which are construed as extension of home space. The valuation question solicited overwhelming support, with over 80% of the respondents willing to pay to recover a possible loss of urban green spaces area by 20%. It yielded a monthly average payment of HK$77.43 (approx USD) per household for five years. Non- instrumental aspects played some role in the respondents' bidding decision. The findings could assist green space planning and nature conservation, and hinted the need to consider the pluralistic community views and expectations in relevant public policies.
Liu, C. and X. Li Carbon storage and sequestration by urban forests in Shenyang, China. Urban Forestry and Urban Greening, 11 (2): Urban forests can play an important role in mitigating the impacts of climate change by reducing atmospheric carbon dioxide (CO 2). Quantification of carbon (C) storage and sequestration by urban forests is critical for the assessment of the actual and potential role of urban forests in reducing atmospheric CO 2. This paper provides a case study of the quantification of C storage and sequestration by urban forests in Shenyang, a heavily industrialized city in northeastern China. The C storage and sequestration were estimated by biomass equations, using field survey data and urban forests data derived from high-resolution QuickBird images. The benefits of C storage and sequestration were estimated by monetary values, as well as the role of urban forests on offsetting C emissions from fossil fuel combustion. The results showed that the urban forests in areas within the third-ring road of Shenyang stored 337,000t C (RMB92.02 million, or $ million), with a C sequestration rate of 29,000t/yr (RMB7.88 million, or $ 1.19 million). The C stored by urban forests equaled to 3.02% of the annual C emissions from fossil fuel combustion, and C sequestration could offset 0.26% of the annual C emissions in Shenyang. In addition, our results indicated that the C storage and sequestration rate varied among urban forest types with different species composition and age structure. These results can be used to help assess the actual and potential role of urban forests in reducing atmospheric CO 2 in Shenyang. In addition, they provide insights for decision-makers and the public to better understand the role of urban forests, and make better management plans for urban forests.
. Cameron, W.F.R., T. Blanuša, J.E.Taylor, A.Salisbury, A.J.Halstead, B.Henricot and K.Thompson The domestic garden - Its contribution to urban green infrastructure. Urban Forestry and Urban Greening, 11 (2): Domestic gardens provide a significant component of urban green infrastructure but their relative contribution to eco-system service provision remains largely un-quantified. 'Green infrastructure' itself is often ill-defined, posing problems for planners to ascertain what types of green infrastructure provide greatest benefit and under what circumstances. Within this context the relative merits of gardens are unclear; however, at a time of greater urbanization where private gardens are increasingly seen as a 'luxury', it is important to define their role precisely. Hence, the nature of this review is to interpret existing information pertaining to gardens/gardening. per se, identify where they may have a unique role to play and to highlight where further research is warranted. The review suggests that there are significant differences in both form and management of domestic gardens which radically influence the benefits. Nevertheless, gardens can play a strong role in improving the environmental impact of the domestic curtilage, e.g. by insulating houses against temperature extremes they can reduce domestic energy use. Gardens also improve localized air cooling, help mitigate flooding and provide a haven for wildlife. Less favourable aspects include contributions of gardens and gardening to greenhouse gas emissions, misuse of fertilizers and pesticides, and introduction of alien plant species. Due to the close proximity to the home and hence accessibility for many, possibly the greatest benefit of the domestic garden is on human health and well-being, but further work is required to define this clearly within the wider context of green infrastructure.
Soares,A. L., F.C.Castro Rego, E.G. McPherson, J.R.Simpson, P.J. Peper and Q. Xiao Benefits and costs of street trees in Lisbon, Portugal. Urban Forestry and Urban Greening, 10 (2): It is well known that urban trees produce various types of benefits and costs. The computer tool i-Tree STRATUM helps quantify tree structure and function, as well as the value of some of these tree services in different municipalities. This study describes one of the first applications of STRATUM outside the U.S. Lisbon's street trees are dominated by Celtis australis L., Tilia spp., and Jacaranda mimosifolia D. Don, which together account for 40% of the 41,247 trees. These trees provide services valued at $8.4 million annually, while $1.9 million is spent in their maintenance. For every $1 invested in tree management, residents receive $4.48 in benefits. The value of energy savings ($6.20/tree), CO2 reduction ($0.33/tree) and air pollutant deposition ($5.40/tree) were comparable to several other U.S. cities. The large values associated with stormwater runoff reduction ($47.80/tree) and increased real estate value ($144.70/tree) were substantially greater than values obtained in U.S. cities. Unique aspects of Lisbon's urban morphology and improvement programs are partially responsible for these differences
Jim,C. Y. and L.L.H.Peng Weather effect on thermal and energy performance of an extensive tropical green roof. Urban Forestry and Urban Greening, 11 (1): This study investigated the weather effect on thermal performance of a retrofitted extensive green roof on a railway station in humid-subtropical Hong Kong. Absolute and relative (reduction magnitude) ambient and surface temperatures recorded for two years were compared amongst antecedent bare roof, green roof, and control bare roof. The impacts of solar radiation, relative humidity, soil moisture and wind speed were explored. The holistic green-roof effect reduced daily maximum tile surface temperature by 5.2°C and air temperature at 10cm height by 0.7°C, with no significant effect at 160cm. Green-roof passive cooling was enhanced by high solar radiation and low relative humidity typical of sunny summer days. High soil moisture supplemented by irrigation lowered air and vegetation surface temperature, and dampened diurnal temperature fluctuations. High wind speed increased evapotranspiration cooling of green roof, but concurrently cooled bare roof. Heat flux through green roof was also weather-dependent, with less heat gain and more heat loss on sunny days, but notable decline in both attributes on cloudy days. On rainy days, green roof assumed the energy conservation role with slight increase instead of reduction in cooling load. Daily cooling load was 0.9kWhm -2 and 0.57kWhm -2, respectively for sunny and cloudy summer days, with negligible effect on rainy days. The 484m 2 green roof brought potential air-conditioning energy saving of 2.80×10 4kWh each summer, equivalent to electricity tariff saving of HK$2.56×10 4 and upstream avoidance of CO 2 emission of 27.02t at the power plant. The long-term environmental and energy benefits could justify the cost of green roof installation on public buildings.
Joye, Y., K.Willems, M.Brengman and K.L. Wolf The effects of urban retail greenery on consumer experience: Reviewing the evidence from a restorative perspective. Urban Forestry and Urban Greening, 9 (1): Over the last three decades solid empirical evidence for the positive influence of greenery on human psychological and cognitive functioning has been steadily accruing. Based on this evidence, researchers and practitioners increasingly realize the importance of urban greening as a strategic activity to promote human wellbeing. Although commercial and retail activities constitute a significant and influential component of urban contexts, a concern is that the stakeholders involved (e.g. merchants) can sometimes be reluctant to integrate vegetation in commercial districts. This can be an important stumbling block for the process of urban greening. In this paper we introduce the concept of Biophilic Store Design (BSD) as the retail design strategy to consciously tap the beneficial effects of vegetation. The central aim of this paper is to demonstrate that the reluctance of certain retail stakeholders to integrate greening practices like BSD is unjustified. Two lines of evidence in support of this claim will be discussed. On the one hand, we sketch a conceptual framework which supports the view that BSD can have restorative effects for those implied in store environments. On the other hand, we review Wolf's multi-study research program on the effects of urban greening on consumer behavior, attitudes, and perceptions. These two lines of evidence show that commercial activities and urban greening are not to be considered as antagonistic but as mutually reinforcing practices.
Cavanagh, J.A.E., P.Zawar-Reza, J.G. Wilson Spatial attenuation of ambient particulate matter air pollution within an urbanised native forest patch. Urban Forestry and Urban Greening, 8 (1): Of interest to researchers and urban planners is the effect of urban forests on concentrations of ambient air pollution. Although estimates of the attenuation effect of urban vegetation on levels of air pollution have been put forward, there have been few monitored data on small-scale changes within forests, especially in urban forest patches. This study explores the spatial attenuation of particulate matter air pollution less than 10 μ in diameter (PM 10) within the confines of an evergreen broadleaved urban forest patch in Christchurch, New Zealand, a city with high levels of PM 10 winter air pollution. The monitoring network consisted of eight monitoring sites at various distances from the edge of the canopy and was operated on 13 winter nights when conditions were conducive for high pollution events. A negative gradient of particulate concentration was found, moving from higher mean PM10 concentrations outside the forest (mean=31.5 μg m -3) to lower concentrations deep within the forest (mean=22.4 μg m -3). A mixed-effects model applied to monitor meteorological, spatial and pollution data indicated temperature and an interaction between wind speed and temperature were also significant (P≤0.05) predictors of particulate concentration. These results provide evidence of the potential role that urban forest patches may play in mitigating particulate matter air pollution and should be considered in plans for improving urban air quality.
. Zhao, M., F.J.Escobedo and C.L.Staudhammer Spatial patterns of a subtropical, coastal urban forest: Implications for land tenure, hurricanes, and invasives. Urban Forestry and Urban Greening, 9 (3): Spatial patterns of tree structure and composition were studied to assess the effects of land tenure, management regimes, and the environment on a coastal, subtropical urban forest. A total of 229 plots in remnant natural areas, private residential, public non-residential, and private non-residential land tenures were analyzed in a 1273km 2 study area encompassing the urbanized portion of Miami-Dade County, USA. Statistical mixed models of structure, composition, location, and land tenure data were used to analyze spatial patterns across the study area. A total of 1200 trees were measured of which 593 trees (49%) were located in residential areas, 67 (6%) in public non-residential areas, 135 trees (11%) in private non- residential areas, and 405 (34%) in remnant, natural areas. A total of 107 different tree species belonging to 90 genera were sampled. Basal area in residential land tenures increased towards the coast while private residential land tenures and natural areas had higher species diversity than non-residential areas. Tree height, crown light exposure, and crown area might indicate the effects of past hurricane impacts on urban forest structure. Land tenure, soil types, and urban morphology influenced composition and structure. Broadleaf evergreen trees are the most common growth form, followed by broadleaf deciduous, palms, and conifers. Exotic tree species originated mainly from Asia and 15% of all trees measured were considered exotic-highly invasive species. We discuss the use of these results as an ecological basis for management and resilience towards hurricane damage and identifying occurrence of invasive, exotic trees.