Patterns and mechanisms of plant community assembly in an industrially degraded ecosystem [Elektronische Ressource] / von Markus Wagner

Frank Wagner

Sujets

• Social work

Informations

• Publié par: friedrich-schiller-universitat_jena
• Publié le: 01 janvier 2004
• Nombre de lectures: 8
• Langue: English
• Poids de l'ouvrage: 5 Mo

Extrait

Patterns and Mechanisms of Plant
Community Assembly in an Industrially
Degraded Ecosystem



Dissertation
zur Erlangung des akademischen Grades
doctor rerum naturalium (Dr. rer. nat.)








vorgelegt dem Rat der Biologisch-Pharmazeutischen Fakultät
der Friedrich-Schiller-Universität Jena



von Diplom-Biologe Markus Wagner
geboren am 06. Dezember 1970 in Baden-Baden



Jena, den 28. Juli 2003
































Gutachter:
1.: ..........................................................................................................
2.: ......................................
3.: ..........................................................................................................
Tag der Doktorprüfung: .....................
Tag der öffentlichen Verteidigung: ...................................................... Contents

List of tables iv

List of figures v

1 Introduction 1

2 The Steudnitz field site 2
2.1 Geography and solid geology…………………………………………………………………..2
2.2 Climate…………………………………………….…3
2.3 Site history…………………………………………………………………………...3
2.4 Environmental impact of the fertiliser production at the Steudnitz site………………………..5
2.5 Soil conditions……………………………………………………………………………….…6
2.6 Previous investigations and the extent of earlier investigations on plant communities………..8

3 The conceptual framework of this study: environmental-filter concepts 10
3.1 Assembly rules………………………………………………………………………………..10
3.2 Limited membership and environmental filters……………………………………………….11

4 Influence of seed dispersal capacity and seedling salt tolerance on order of colonisation 15
4.1 Introduction……..………………………………………………………………………….…15
4.2 Methods……..…………………………...16
4.2.1Role of dispersal type………………………………………………………………….....16
4.2.2 Role of seedling salt tolerance………………………...…16
4.2.2.1 Experiental design………………………………………………………………….16
4.2.2.2 Data analysis…………………………………..……17
4.3 Results……………………………………………………………………………………...…17
4.4 Discussion………………………………..19
4.4.1 The method used for salt tolerance characterisation……………………………………..19
4.4.2 Order of colonisation…………………………………………….....20

5 Soil seed bank 22
5.1 Introduction……………………………………………………………………………...……22
5.2 Methods……………………………….....23
5.2.1 Sampling methods……………………………………………………………………….23
5.2.2 Data analysis and seed bank classification………………………....24
5.3 Results………………………………………………………………………………………...25
5.3.1 Seed bank composition…………………………………………………………………..25
5.3.2 Vertical profile and seed bank classification……………………………………….……28
5.4 Discussion……………………………………………………………..…30
5.4.1 Methodological aspects…………………………………………….30
5.4.2 Seed bank composition and vertical distribution………………………………………...30
i 5.4.3 Seed bank classification………………………………………………………………….31
5.4.4 Soil seed bank and plant community assembly………………….…32

6 Spatial vegetation patterns and underlying soil gradients 34
6.1 Introduction…………………………………………………………………………………...34
6.2 Methods………………………………….35
6.2.1 Field methods…………………………………………………………………………….35
6.2.2 Soil analysis………………………...35
6.2.3 Exploratory data analysis………………………………………………………………...36
6.2.3.1 Correlation between abiotic parameters………………………36
6.2.3.2 Pairwise association between plant species……………………………………...…36
6.2.3.3 Ordination…………………………………………………………………………..37
6.3 Results………………………………………………………………………………………...38
6.3.1 Correlation between abiotic parameters………………………………………………....38
6.3.2 Pairwise association between plant species……………………...…39
6.3.3 Ordination……………………………………………………………………..41
6.3.3.1 Canonical Correspondence Analysis (CCA)……….……………………………....41
6.3.3.2 General Linear Models……………………………………..……………43
6.4 Discussion……………………………………………………………………………………..46
6.4.1 Correlation between soil parameters…………………………………………………….46
6.4.2 Pairwise association between plant species……………...47
6.4.3 Canonical Corresponence Analysis……………………………………………………...48
6.4.3.1 CCA model quality………………………………....48
6.4.3.2 Main environmental gradients……………………………………………………...48
6.4.3.3 Abiotic vs. biotic filter……………………………………………………………...49
6.4.3.4 Life history strategy – a trait with predictive value for assembly in this study?…..50

7 Nutrient imbalance and plant community structure: a nutrient addition experiment 54
7.1 Introduction…………………………………………………………………………………...54
7.2 Methods……………………………….…55
7.2.1 Experimental design……………………………………………………………………..55
7.2.2 Data analysis…………………………………..57
7.2.2.1 Univariate community characteristics……………………………………………...57
7.2.2.2 Species-specific response and community response………….58
7.3 Results…………………………………………………………………………………..…….59
7.3.1 Univariate community characteristics…………………………………………………...59
7.3.2 Species-specific response and community response………………….………62
7.4 Discussion…………………………………………………………………………………..…69
7.4.1 Nutrient limitation…………………………….69
7.4.2 Species-specific response to treatments……………………………………….…………71
7.4.3 Changes in community structure……………………………………………...72
ii
8 Conclusions and directions for future research 75
8.1 Plant community assembly at the Steudnitz site……………………………………………...75
8.1.1 Early colonisation and priority effects………………………………………………...…75
8.1.2 Curently-operating environmental filters….……………………………………………..77
8.2 Abiotic stress and plant community assembly in industrial ecosystems…………...…………78
8.3 Directions for future research…………………………………………………………………80

Summary 82

Zusammenfassung 84

References 86

Appendices A1-A9

Acknowledgements


























iiiList of Tables

Table 2.1. Soil parameters (means ± standard deviation) from the years 1990 (1991), 1996 (1997)
and 1999 in the proximal part of the Steudnitz lower slope. .........................……..........................................7

Table 5.1. Number of species in te vegetation, seed bank density and number of species per seed
bank sample (pooled 0-10 cm) for the years 2000-2002. ......……................................................................26

Table 5.2. Summary of the repeated measures ANOVAs for average number of species per
subsample (two depths: 0-5 cm, 5-10 cm) and average number of seeds per dm³ soil (three
depths: 0-2 cm, 2-5 cm, 5-10 cm). ...................................................................................................…….....27

Table 5.3. Seed bank persistence of 26 species occurring in the vegetation or soil seed bank at the
Steudnitz field site. ……...............................................................................................................................29

Table 6.1. Spearman rank correlation coefficients for pairwise correlations between 10 abiotic
factors (9 soil parameters and slope angle). ............................……..............................................................39

Table 6.2. Explanatory power of the Canonical Correspondence Analysis of the 140 lower slope
1 m² relevés. .…….........................................................................................................................................41

Table 7.1. Summary of the different treatments applied in the fertiliser addition experiment. .....……...…....56

Table 7.2.