Transcript The vegetation of the park lawns of Munich

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