The vegetation of the park lawns in Munich A diploma thesis in biology about vegetation ecology and city ecology Table of contents 1 Introduction 2 Means and techniques 3 Results 4 Discussion 5 Summary 1 Introduction Def.: Park lawns are grasslands in • Gardens • Parks • Sports grounds that become regular cut and stepped on. They are mowed according to their height and the weather up to 35 times per year. 1 Introduction Interrelation of the site factors light sun climate temperature water ground water soil nitrogen time age use cutting PLANT species number fauna earthworms competition pointer values 2 Means and techniques 2 Means and techniques A. Abiotical factors 5° 6° 7° 8° 9° 10° 16 physical variables 95% 90% 85% 80% 10° Air temperature [°C] B. Biotical factors C. Use factors Relative air humidity [%] 49 site factors (vegetation) 6 care factors (mowing) 2 Means and techniques A. Abiotical factors List of biotic influence factors – won by maps or aerial photograph • Climate air temperature [°C], relative air humidity [%] • Exposition sun-exposed face [m²], entire face [m²] • Position geographical coordinates, GPS east/north [m] • Sea level distance to the middle sea level [m] • Groundwater state middle [m], variation [m], distance [m] • Soil types arranged according to usable humidity 2 Means and techniques B. Biotical factors List of biotic factors – won by fieldwork • Growth form therophytes (1-2a), geophytes (earth plants) • Species number number of different plant species per site • Neophytes foreign plants or grade of human influence • Legumes (Fabales) distinguish burdened and extensive sites • Light-number forest plants have a small light compatibility • Temperature-nu. optimal 15 °C at day and 10 °C at night • Nitrogen-number nutrient supply or degree of fertilization • Salt-number osmotic budget or transpiration coefficient 2 Means and techniques C. Use factors today 1613 The use on some sites is since over 300 years the same (Hofgarten). 1795 today Step load through bumpkin paths in the English Garden 2 Means and techniques C. Use factors List of the six use factors – raised by research • Age • time [a] and influence of natural succession R-strategists are replaced by C-strategists • Step load stress-tolerant S-strategists (Poa annua) • Cut frequency cuts per year [aˉ¹ ], mowing is the strongest disturbance to the vegetation • Sum of the cuts adaptation to the cutting over time • Cut technique sickle mower, spindle mower, girder mower and sheep • Degree of human influence describes the intensity of use and disturbance 3 Results 3 Results A. Descriptive statistic raw data (frequency) Species number (x) and frequency (y) Artenzahl 60 50 Frequency 40 30 20 Std.abw. = 7,96 10 M ittel = 14 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. N = 195,00 0 5 10 15 20 25 30 35 40 Species number Artenzahl B. Analytical statistic mathematical processing (correlation, regression) 3 Results B. Analytical statistic Correlation (PEARSON) – math. relationship when coefficient > 0,5 Disturbance indicators Flower meadows Temperature, groundwater state (distance) Relative air humidity, soil type (usable humidity) Therophytes (1-2a), Light-number, Temperaturenumber, Nitrogen-number, Salt-number Age, cut frequency, sum of cuts, step load, degree of human influence Fabales, herbs, grasses, species number, diversity, number of neophytes, geophytes, hemikryptophytes Cut technique (e.g. sheep) 3 Results B. Analytical statistic number Species Artenzahl Regression curve of a biotical factor - number of different sorts of Fabales (x) with species number (y) 50 40 30 20 The species number is strongly positively correlated with the number of legumes 10 0 1 2 3 4 5 6 7 Fabales Number of different sorts of Fabales 3 Results B. Analytical statistic Species number 50 Species number Species number Species number Regression curves of the pointer values Light-number and Nitrogen-number (x) with species number (y) 40 30 20 10 0 6,5 7,0 7,5 8,0 Light-number Light-number The regression curve shows that the species number has an optimum (17.9 species) with the Light-number of 6.89. 50 40 30 20 10 0 4,0 4,5 5,0 5,5 6,0 6,5 7,0 7,5 Nitrogen-number Nitrogen-number The Nitrogen-number correlates negatively with the species number. 3 Results B. Analytical statistic Regression curve of a use factor – number of cuts per year (x) with species number (y) number Species Kind number 50 40 30 20 In adornment lawns the species number is higher than in most park lawns. 10 0 0 10 20 Cut frequency [1/a] 30 Number of cuts per year 3 Results B. Analytical statistic Cluster analysis – section of a hierarchical dendrogram (similarity tree) of the species, the upper ones resemble more Strong light plants (Achillea millefolium), very small growing (Poa trivialis), meagreness hands (Holcus lanatus) 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) 3 Results B. Analytical statistic degree of human influence step load cut frequency cut technique sum of cuts age Disturbance indicators species number Flower meadows Canonical correspondence analysis – ordination of use factors 3 Results B. Analytical statistic Nitrogennumber degree of geophytes number of neophytes human influence Salt-number step load therophytes cut frequency cut technique Temp.-number Light-number sum of cuts H. rosulata (Bellis perennis ) herbs age species number Disturbance indicators Flower meadows Fabales grasses CCA – ordination of use factors and biotical factors 4 Discussion 4. Discussion Progressive (natural) and regressive (anthropogen) succession final stage temporary stage forest shrubs, shrubbery pioneer stage grasses, herbs raw earth fallow years Progressive succession spindle mower girder mower chainsaw Regressive succession 4 Discussion 4. Discussion Transformation of park lawns into species-rich flower meadows Mowing once or twice annually Sage smooth oat meadow (Arrhenatherion elatioris) Girder mower or spindle mower Sickle mower shreds the blade of grass Cut height more than 7 cm Insects and macrofauna can survive (lizards) Nutrients in the upper ground must be reduced through impoverishment Semination on raw earth or overseeding Nitrogen entry through the air is 50 kg haˉ¹ aˉ¹ The plants must develop fully before they are mowed (= 5 g mˉ² aˉ¹) Best by the means of the hay flower sowing with autochthonous seed 5 Summary 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. 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. The vegetation of the park lawns in Munich Jörn Kimpel