Presentation on theme: "Site Productivity and Land Classification"— Presentation transcript:
1Site Productivity and Land Classification Lecture 13:Forest Ecology 550
2Objectives Discuss indirect ways to measure site productivity Briefly discuss land classificationIntroduce ecosystem process modelsWhat role can remote sensing play in estimating forest species composition, structure, and function.
3Site Productivity Definition Sites potential to produce one or more natural resourcesSustainableManage for multiple resources
4Site Productivity: indirect measurement approaches 1) Site index: Forest measurement to measure site qualityBased on height of the dominant and co-dominant trees based on some standard ageAge depends on location and stand typeTypically 50 years but..
5Forest Productivity: Site Index Curve Anamorphic curves
6Site index curves: Pros/cons Easy and inexpensiveHeight growth is less sensitive than basal area growth to stocking density.Consvery site dependent (soils, topography, aspect)Differs among speciesRequires trees growing on the siteCannot capture dynamic nature of tree growth and global change
7Site Productivity: indirect measurement approaches 2) Overstory tree speciesEach species occupies its own nicheBlack spruce image from:
8Site Productivity: indirect measurement approaches 2) Overstory tree speciesEach species occupies its own nicheAdvantagesAllows you to make quick assumptions about a given areaDisadvantagesChallenging for species that are able to exist in a wide range of climates
9Site Productivity: Indirect measurement approaches 3) understory speciesDefinition: use of understory species to make classifications of siteAdvantages:More sensitive to micro-climate differencesIndicator speciesDisadvantagesWhat about disturbanceIndicator species: have such a small ecological niche that their presence or absence can mean different things.Marsh marigold: fen indicator species
10Site Productivity: Indirect measurement approaches 3) understory speciesOther examples:Ephemerals often have a narrow ecological niche
11Site Productivity: Indirect measurement approaches 4) Ecological Site ClassificationPrimary means is through Habitat TypingIdentified by distinct understory plant assemblagesnatural vegetation to identify ecologically equivalent landscape unitsgrowthnatural resource use potential
12Soil usually sand to loamy sand. At least two species present:low sweet blueberry, wintergreen,sweet fern, pipsissewa, cow wheat, witch hazel, maple-leafviburnum, pointed leaf tick treefoilwitch hazel, maple-leafviburnum, pointedleaf tick treefoilSpecies on right rareor absent blueberry,wintergreenor absentAt least 2 presenthoneysuckle, twistedstalk, partridgeberry,yellow beadlilly, shieldfern, ironwoodSum of the coverage >2x’s the sum of speciesIn right boxtrailing arbutus, bearberry, reindeer mosshazelnut, falseSoloman’s seal,barren strawberryAQVibPMVQAEAQV
13Examples of WI Habitat Types Epigaea:Vaccinium angustifoliumMaianthemum canadense:Viburnum acerfolium (maple-leaf viburnum):Osmorihza:coptis_goldenthread:
14Examples of WI Habitat Types MaianthemumCoptisSweet anise/osmorhiza
15Habitat Types: Comparisons in WI Litterfall C and N generally increase from low quality to high quality habitat typeFor more general information about specific habitat types please feel free to check the website listed below.
16Habitat Types Advantages Disadvantages Fairly detailed Qualitative formulaeDisadvantagesMay take some time to identify the factors in the stand
17Site Productivity: Indirect Measurement Approaches 5) Environmental Relationships/factorsSimple relationships between one of more variable and tree growth.from E.C. Steinbrenner Forest soil productivity relationships. In Forest Soils of the Douglas-fir Region).
18Environmental relationships/factors cont.. from E.C. Steinbrenner Forest soil productivity relationships.In Forest Soils of the Douglas-fir Region).
20Site Productivity: Indirect Measurement Approaches 6) Ecosystem Process Modelsbased on biophysical and ecological principlesevery physiological process model has some level of empiricism
21PPT evaporation LAI transpiration LAI Soil water Soil water outflow General Outline for the conceptual framework of biome-BGCPPTevaporationLAItranspirationLAISoil waterphotosynthesisSoil wateroutflowrespiration
22Remember our radiation lecture? We can see in this figure that red is strongly absorbed by vegetation and infra red is strongly reflected.
23Site Productivity: Indirect Measurement Approaches 7) Remote SensingCommon Vegetation indices derived from radiation reflectance measured using satellitesSimple ratio = (near infra-red(NIR)/red (R) wavelength)Normalized Difference Vegetation Index(NDVI)= (NIR - R)/(NIR + R)
24Site Productivity: Indirect Measurement Approaches 7) Remote SensingNormalized Difference Vegetation Index(NDVI)= (NIR - R)/(NIR + R)See Tom’s book about this a bit more.
25Remote Sensing: Global Classification of Vegetation
26Predicted versus Measured LAI What does ETM mean on this slide presentation?Corn LAI= *CCIca R2=0.63Soy LAI= *CCIsa R2=0.27ETM+ predictions of Aug. LAICorn LAI= *CCIcj R2=0.61Soy LAI= *CCIsj R2=0.58ETM+ predictions of July LAI
28Generally how do you get the remote sensed values?
29Modis GPP project GPP (gC m-2 d-1) = PAR * fAPAR * g Where: PAR = from climate modelfAPAR = from MODIS reflectancesg ( gC MJ-1) = GPP / APARMODIS g from lookup tableSpatial Resolution is 1 kmTemporal Res. is 8-day mean
31Remote Sensing Disturbance - Disturbances are an important component of any forest ecosystem- Disturbances have no effect on the C budget if the system is insteady stateFire frequency and extent hasincreased 270% in recent decadesIn Saskatchewan and Manitoba98199519898150 km
32Fire scar profiles taken from 2003 NDVI seasonal data. Hudson Bay2003 NDVI 3-date Compositemax leaf areaFire dateleaf expansionNDVI: normalized difference vegetation index. NDVI=(near infrared-vis)/ (near infrared + Vis)snowmelt2003 fireFire scar profiles taken from 2003 NDVI seasonal data.Selected burn areas shown in image on the right.2002 MODIS Image Manitoba-Saskatchewan