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Publié par | universitat_bayreuth |
Publié le | 01 janvier 2009 |
Nombre de lectures | 19 |
Langue | English |
Poids de l'ouvrage | 2 Mo |
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Volume 5 . 2009
ISSN 1862-9075
BayCEER-online
Volker Audorff
Vegetation ecology of springs:
ecological, spatial and
temporal patterns
BayCEER-online
ISSN 1862-9075
BayCEER-online is the internet publication series of the University of Bayreuth,
Bayreuth Center of Ecology and Environmental Research (BayCEER)
© 2009 by Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth
The use of general descriptiver names, registered names, trademarks, etc. in this publication does not
imply, even in the absence of a specific statement, that such names are exempt from the relevant
protective laws and regulations and therefore free for general use.
Cover design: Schlags & Schlösser Kommunikation GmbH, 95444 Bayreuth, Germany
WorldWideWeb: http://www.bayceer.uni-bayreuth.de
BayCEER-online Volume 5 / 2009
Die vorliegende Arbeit von Herrn Volker Audorff, geb. am 06.12.1969 in
Marktredwitz, wurde in der Zeit von Februar 2003 bis Januar 2009 in Bayreuth am
Lehrstuhl für Biogeografie unter der Betreuung von Prof. Dr. Carl Beierkuhnlein
angefertigt.
Vollständiger Abdruck der von der Fakultät für Biologie, Chemie und Geowissen‐
schaften der Universität Bayreuth genehmigten Dissertation zur Erlangung des
akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.).
Dissertation eingereicht am: 08. Januar 2009
Zulassung durch die Promotionskommission: 14. Januar 2009
Wissenschaftliches Kolloquium: 25. Mai 2009
Amtierender Dekan: Prof. Dr. Axel Müller
Prüfungsausschuss
1. Prof. Dr. Carl Beierkuhnlein (Erstgutachter)
2. Prof. Dr. Björn Reineking (Zweitgutachter)
3. Prof. Dr. Stefan Peiffer (Vorsitz)
4. PD Dr. Gregor Aas
5. PD Dr. Gian‐Reto Walther
Tales sunt aquae, quales terrae, per quas fluunt.
Plinius der Ältere
Contes
Contents
Summary 1
Zusammenfassung 3
Introduction 5
Background 5
Research objectives and hypotheses 9
Synopsis 12
Outline of the manuscripts 12
Summarising conclusions and emerging research challenges 13
References 17
List of manuscripts and specification of own contribution 21
Manuscript 1 23
The role of hydrological and spatial factors for the vegetation of Central
European springs
Manuscript 2 47
Drivers of species composition in siliceous spring ecosystems:
groundwater chemistry, catchment traits or spatial factors?
Manuscript 3 69
Is the delineation of niche attributes a matter of spatial scale?
Manuscript 4 91
Inter‐annual vegetation dynamics in forest springs
Manuscript 5 107
Are bryophytes better indicators for inter‐annual changes in spring water
quality than vascular plants?
List of publications 126
Acknowledgements 129
Statement 131
Summary
Summary
Acidification is a phenomenon, which affected the forested catchments of the northern
hemisphere severely over recent decades. Acidic depositions depleted the buffering
capacities of soil and groundwater, what lead to an impairment of forests, headwaters, and
lakes. Even though the depositions were reduced considerably since the early 1990s, the
recovery of catchments was found to occur time‐delayed. The grade of recovery was found to
vary significantly between regions.
Biomonitoring is an appropriate tool to detect spatial and temporal patterns of ecosystem
alterations, such as acidification and recovery. However, to know the interrelationships
between organisms and their environment is an indispensable precondition for the
identification of indicator species. The complexity of ecosystems and ecological processes
hampers this quest oftentimes. Springs provide a natural setin g that minimises such
constraints. Compared to other habitat types, external factors are less relevant, which makes
it easier to relate changes in species abundances to changes in their environment. Studying
this species‐environment relationship, here the response of plant species to the acidification
of the spring waters was of particular interest.
In a survey of five regions in Central Europe ‐ taking spatial, hydrophysical as well as
hydrochemical parameters of the springs into account ‐ it was clearly shown that the species
composition of springs is essentially determined by the spring water chemistry, and more
precisely by the gradient of acidity and nutrient availability. This connection was reflected by
spatial patterns within and between the regions. These patterns provide useful ecological
information about spring water quality and in return about the acidity status of their forested
catchments.
Including catchment traits ‐ like bedrock, climatic parameters, and forest vegetation ‐ in the
analyses, these emerged to be relevant for the species composition of springs, but less than
the spring water chemistry. A path analysis showed that the catchments affect the vegetation
of springs not directly, but indirectly via the determination of spring water quality. Hence, the
catchments are a part of the functional chain, which is driven by the atmospheric depositions.
The pH‐value was found to represent the gradient of acidity and nutrient availability best. It
can serve as a proxy measure that can be related to species occurrence and to species
dynamics respectively, aiming to identify indicator species for assessing the status and
alterations of spring water quality.
With the aim to delineate niche optima and amplitudes, which in return can serve