Presentation on theme: "The vegetation of the park lawns in Munich"— Presentation transcript:
1 The vegetation of the park lawns in Munich A diploma thesis in biologyabout vegetation ecology and city ecologyThe topic of my lecture is the vegetation of the park lawns in Munich. Welcome to the presentation of my diploma thesis. My name is Joern Kimpel. Everyone can convince himself through a visit of the English Garden or his private garden, that there are different shapes of park lawns.
2 Table of contents 1 Introduction 2 Means and techniques 3 Results 4 Discussion5 SummaryFirst I want to tell you about the contents of my presentation. We start with the introduction and work through point by point over the means and techniques, the results and the discussion up to the summary. First I explain the basics then the results. As you can see all you need for the fieldwork is a paper block, a ball-point pen and a magnifier.Sometimes an umbrella is very useful.
3 Def.: Park lawns are grasslands in 1 IntroductionDef.: Park lawns are grasslands inGardensParksSports groundsPresent job deals with the vegetation ecology of the Munich park lawns. The purpose of the diploma thesis is to give a survey of the local plant societies. The most frequent vegetation models of park lawns are cutting-lawns and step lawns. They are mowed up to 35 times per year. These intense well-kept lawns become more and more converted to landscape lawns and biotope faces. The relationship between usage and number of species stands in the foreground of this work. Except for this crucial question the question is handled, how the current use can be improved from nature conservation aspects.that become regular cut and stepped on.They are mowed according to their height and the weather up to 35 times per year.
4 Interrelation of the site factors 1 IntroductionInterrelation of the site factorslight climate water soilPLANTfauna competition time usesun temperature ground water nitrogenspecies numberearthworms pointer values age cuttingOn this topic of the city ecology one finds only few works. Park lawns are even poorer than meadows. They appertain definitely to the plant society Lolio-Cynosuretum, nevertheless they are distinguished by it. The selection of certain species associated by the cattle is missing. There are different opinions about the most important effective factors: for example climate, soil, disturbance or competition, time and disturbance. In this effect wickerwork we see factors and under each one an example.A pointer value is the ecological behavior of a plant at a site under competition. So a species can be compared with other species. For example there are climatic values like light or soil values like nitrogen for every sort of plant. These testet pointer values are listed in special ecology books.
5 Relative air humidity [%] 2 Means and techniques2 Means and techniquesA. Abiotical factors physical variables5°6°7°8°95%9°90%10°85%80%The means and techniques part describes the theoretic basics. I distinguish the factors in abiotical, biotical and use factors.In part A 16 physical variables are raised out of maps for the data base, for example temperature and relatice air humidity. The city air is drier and fog-poorer and forms climate districts as we can see here.The 49 biotical influencing factors in part B handle the vegetation.Then 6 use factors describe the impact of human influence like mowing in part C.All factors are classified mathematically.For example there are five classes for the air temperature classified from 1 to 5.10°Air temperature [°C]Relative air humidity [%]B. Biotical factors site factors (vegetation)C. Use factors care factors (mowing)
6 2 Means and techniquesA. Abiotical factorsList of biotic influence factors – won by maps or aerial photographClimate air temperature [°C], relative air humidity [%]Exposition sun-exposed face [m²], entire face [m²]Position geographical coordinates, GPS east/north [m]Here you see the list of abiotical influence factors. They were won by geographical or meteorological maps or aerial photograph. Analogue and digital types of maps or photograph were used.The climate maps that you have seen before are from a special meteorological investigation of the Munich city climate. Through the processing of digital aerial photos the sun-exposed face and the entire face can be estimated (photogrammetry).The geographical position (GPS coordinates) and the sea level of the sites is given by a digital map.The groundwater state, its middle, variation and distance are from a geo-hydrologic map. The four different soil types can be found in a geological map of Munich.You see that the prominent site Munich delivers plenty information for an evaluation.Sea level distance to the middle sea level [m]Groundwater state middle [m], variation [m], distance [m]Soil types arranged according to usable humidity
7 B. Biotical factors List of biotic factors – won by fieldwork 2 Means and techniquesB. Biotical factorsList of biotic factors – won by fieldworkGrowth form therophytes (1-2a), geophytes (earth plants)Species number number of different plant species per siteNeophytes foreign plants or grade of human influenceLegumes (Fabales) distinguish burdened and extensive sitesThe more a site is mowed the more the plants are selected by their growth form. Therophytes for example have more chances to flower and to propagate as they live for a short time. They can adapt to the rhythm of mowing. A geophyte or earth plant as we see on the photo is the Meadow saffron (Colchium autumnale). Geophytes can survive by their spring onion under earth. The reason why sweetness grasses can survive cutting easily is, that their basal meristeme or growth tissue are not destroyed while mowing. They can rise again after step load, through corresponding growth at the knots. So we can find, similar to the alpine meadows, a high species number of stress resistant grasses.The new immigrants are called Neophytes among the plants. They have come to central Europe since the discovery of Amerika. The number of Neophytes determines the degree of human influence.Legumes is a plant family that can fix the aerial nitrogen in its roots. So one can find only a few different species of Fabales on eutrophic or fertilized sites.The pointer values are enormous important. They show the compatibility of the plants to influence factors under competition.Most of the plants are herbs from a forest society, so they don`t like intensive sunlight.Over a temperature of 55°C the proteins get irreversibly denaturised.The nitrogen number marks the degree of fertilization. Plants which can only grow on poor soils are disadvantaged to nitrophile plants.The optimum of most plants is near a very small salt concentration. The salt concentration in city grounds is higher because of air pollution, salt scattering in the winter and fertilization.Light-number forest plants have a small light compatibilityTemperature-nu optimal 15 °C at day and 10 °C at nightNitrogen-number nutrient supply or degree of fertilizationSalt-number osmotic budget or transpiration coefficient
8 The use on some sites is since over 300 years the same (Hofgarten). 2 Means and techniquesC. Use factorstoday1613The use on some sites is since over 300 years the same (Hofgarten).The Hofgarten is over 300 years old. Its use is the same today. The English Garden was long-time used for agriculture. Now there are park lawns. It is to be mentioned in this case that Munich allowed the entering of the lawns as a first city in Bumpkin or wild paths can not be prevented either with barriers, as they satisfy the needs of the park visitors.1795todayStep load through bumpkin paths in the English Garden
9 C. Use factors List of the six use factors – raised by research 2 Means and techniquesC. Use factorsList of the six use factors – raised by researchAge time [a] and influence of natural successionR-strategists are replaced by C-strategistsStep load stress-tolerant S-strategists (Poa annua)Cut frequency cuts per year [aˉ¹ ], mowing is the strongest disturbance to the vegetationSum of the cuts adaptation to the cutting over timeOver a long time of use more and more species can settle in a site.First comers, pioneer plants or ruderale species (R-strategists like Chenopodium bonus-henricus ) are the first to grow on raw earth.After a few years the park lawn vegetation consists of many competition-strong species (C strategists like Poa pratensis or Taraxacum officinale).The step load is to the cut the second-greatest stress factor. Here particularly stress-tolerant grasses can survive (for example Poa annua). Too strong step load results in open places in the sod.The cut frequency is the strongest disturbance to be able to influence the vegetation. Species like Trifolium repens can get along with the conditions as they can spread vegetative.As cut technique there are three kinds of mowers and the use of sheep in the northern part of the English Garden.The natural succession is interrupted through the human being, so that only hemicryptophytes (Plantago major = creeper) and few geophytes can settle in the park lawns. The climax society with wood plants can never be reached.The degree of human influence is sorted by the intensity of use. It reaches from play grounds up to flower meadows.Cut technique sickle mower, spindle mower, girder mower and sheepDegree of human describes the intensity of influence use and disturbance
10 Species number (x) and frequency (y) 3 Results3 ResultsDescriptive statisticraw data (frequency)Species number (x) and frequency (y)The frequency of the factor species number. Easy to recognize is the normal distribution curve. The average species number is 14. The standard deviation is 7.96 Park lawns have a small species number.FrequencyIn part A of the result part the won data is shown by means of descriptive statistic such as frequency, standard deviation, minima, maxima or percentage.In the last part B the data is processed by mathematical analysing software for example correlation or regression.The most important question is, of what the species number depends.Species numberB. Analytical statisticmathematical processing (correlation, regression)
11 B. Analytical statistic 3 ResultsB. Analytical statisticCorrelation (PEARSON) – math. relationship when coefficient > 0,5Disturbance indicatorsFlower meadowsTemperature,groundwater state (distance)Relative air humidity,soil type (usable humidity)Therophytes (1-2a),Light-number, Temperature-number, Nitrogen-number,Salt-numberFabales, herbs, grasses,species number, diversity,number of neophytes,geophytes, hemikryptophytesAge, cut frequency,sum of cuts, step load,degree of human influenceCut technique(e.g. sheep)To collect data is easy, to interpret it is difficult. In this section the mathematical relationships of the site factors to each other are described. First I want you to get to know the correlation coefficient by Pearson. Here one can form two different groups, the disturbance indicators and the flower meadows. The factors correlate positive within the group and correlate negative with the other group. A correlation of two features is not absolutely tantamount to a functional or causal connection. Age is in the left group because of the accumulation of all disturbance factors over time.
12 B. Analytical statistic 3 ResultsB. Analytical statisticRegression curve of a biotical factor - number of different sorts of Fabales (x) with species number (y)Species numberNitrogen fertilizing inhibits Legumes with their bacteria (Rhizobium is an Azotobacter) fixing nitrogen, max. 300 kg haˉ¹ aˉ¹ (30 g mˉ² aˉ¹). So the species number rises with the number of different sorts of fabales. On a poor soil is a higher species number. One speaks of the clover fatigue on eutrophic sites.The species number isstrongly positivelycorrelated with thenumber of legumesNumber of different sorts of Fabales
13 B. Analytical statistic 3 ResultsB. Analytical statisticRegression curves of the pointer values Light-number and Nitrogen-number (x) with species number (y)Species numberSpecies numberThe regression curve shows that the species number has an optimum (17.9 species) with the Light-number of 6.89 that is 30% relative illumination.The Nitrogen-number correlates negatively with the species number.The scale of the pointer values has nine parts.Light-numberNitrogen-numberThe regression curve shows that the species number has an optimum (17.9 species) with the Light-number of 6.89.The Nitrogen-number correlates negatively with the species number.
14 B. Analytical statistic 3 ResultsB. Analytical statisticRegression curve of a use factor– number of cuts per year (x) with species number (y)Species numberThe diagram of number of cuts per year and the species number shows that there are meadows with 1 to 3 cuts, park lawns with 12 to 22 cuts per year and adornment lawns that are cut 35 times. The last ones you can find in the Hofgarten or nearby the castle Nymphenburg.In adornment lawns the species number is higher than in most park lawns.Number of cuts per year
15 B. Analytical statistic 3 ResultsB. Analytical statisticCluster analysis – section of a hierarchical dendrogram (similarity tree) of the species, the upper ones resemble moreStrong light plants (Achillea millefolium),very small growing (Poa trivialis),meagreness hands (Holcus lanatus)The result of a special ecological program is a hierarchical dendrogram (similarity tree). This dendrogram is the similarity tree of the species. One can distinguish certain groups of species. The top of the dendrogram build the stress-tolerable plants (S-strategists). They have in common a small growth and can live on poor soil.Then the step-resistant plants follow with dryness-resistant grasses with extreme cut comptability.Finally the bigger rosette plants follow with average-high meadow plants and humidity indicators.The following species belong more and more to the highgrowing meadows (Anthriscus sylvestris, Trifolium pratense) and clearings (Festuca rubra ssp. rubra, Rumex acetosa). This goes on to the forest society, which plants differ most in all influence factors. One can say in conclusion that with increasing biomass and leaf surface the similarity of the plant species to each other decreases. The plants follow the natural progession.Step plants (Plantago media),dryness-resistant grasses (Elymus repens),extreme cut compatibility (Agrostis stolonifera)Rosette plants (Bellis perennis),average-high meadow plants (Veronica filiformis), humidity indicators (Ranunculus repens)
16 B. Analytical statistic 3 ResultsB. Analytical statisticdegree of human influenceThe dimensionless vectors indicate the relationships between the use factors. Are there two vectors opposite, they are correlated negatively with each other. If they lie they next to each other or being parallel, the factors are similar or correlated positively with each other. The longer the vector is, the more effective it is for the whole system. The cut frequency vector faces the species number directly.One can as distinguish like the Pearson-correlation between disturbance indicators at the left and flower meadows at the right.Disturbance indicatorsFlower meadowsCanonical correspondence analysis – ordination of use factors
17 B. Analytical statistic 3 ResultsB. Analytical statisticdegree of human influenceIn this ordination we can see bioticalal factors together with use factors. One can distinguish between disturbance indicators at the left and flower meadows at the right.Disturbance indicatorsFlower meadowsCCA – ordination of use factors and biotical factors
18 4 Discussion4. DiscussionProgressive (natural) and regressive (anthropogen) successionfinal stageforesttemporary stageshrubs, shrubberypioneer stagegrasses, herbsraw earthfallowPark lawns are similar to small clearings what concerns the light. If the human being renounced completely the hay, the park lawns would develop slowly to a forest. The human being counteracts this natural succession through measures as deforestation and hay. One speaks then of regressive succession and a subclimax society.If the sites of the adornment lawns are cut very often, these sites develop to extreme biotopes (ecological niche) because they are disturbed frequently. So we can find in the cutting-lawns a higher species number than in regular park lawns.The forest herbs are distinguished from each other strongly in the growth form.The environmental factors in the forest are adjusted.The cutting-lawns are very similar in the growth form.The environmental factors are very different there. The extreme circumstances like light or cutting require a small growth form.yearsProgressive successionspindle mowergirder mowerchainsawRegressive succession
19 4 Discussion4. DiscussionTransformation of park lawns into species-rich flower meadowsMowing once or twice annuallySage smooth oat meadow (Arrhenatherion elatioris)Girder mower or spindle mowerSickle mower shreds the blade of grassCut height more than 7 cmInsects and macrofauna can survive (lizards)Nutrients in the upper ground must be reduced through impoverishmentThe majority of park visitors tended with a questioning towards a blossom-rich meadow.A lime half dry grassland therefore a sage smooth oat meadow (Arrhenatherion elatioris) is an ideal plant society in my opinion. It is mowed only once more rarely twice annually. The species number can most simply be increased if one lowers the cut frequency. The nitrogen entry through the air must be calculated with average 50 kg of ha¯¹ a¯¹ (= 5 g of m¯² a¯¹).Nitrogen entry through the air is 50 kg haˉ¹ aˉ¹(= 5 g mˉ² aˉ¹)The plants must develop fully before they are mowedSemination on raw earth or overseedingBest by the means of the hay flower sowing with autochthonous seed
20 5. Summary Synecological investigation of the Munich park lawns The vegetation of the Munich park lawns is very similar; the faces are often mowed, which results in a small species variety. The nutrient number, the growth form geophytes and the disturbance through the human being are the strongest site factors of the entire investigation.The most important abiotical factors are the relative air humidity, the groundwater state and the air temperature.The effective biotical factors are stress indicators like Nitrogen-number, Salt-number and the growth form therophytes.The most influence of the use factors has the cut frequency on the species number. It is therefore the factor which can be changed at the easiest for a higher species number if one wants to convert the park lawns into species-rich flower meadows.On the photo you see the hay flower seeding. Hay from the Garchinger Heath is distributed onto raw lime gravel on a receiver face.I suggest a transformation of the faces into meadows which are cut two or three times per year. In order to get a beautifully flourishing meadow, one must seed meager lawn species with the method of the hay flower seeding.
21 The vegetation of the park lawns in Munich Finally I show you a satellite photo of Munich. As you can see, 20% is covered with vegetation. I hope you have the possibility to enjoy during beautiful weather in the summer the cool microclimate of the city parks. Thanks for your attention. Has anybody got a question?Jörn Kimpel