Master thesis Summer term 2011 The effect of native forest dynamics upon the arrangements of species in oak forests-analysis of heterogeneity effects at the example of epigeal arthropods Die Auswirkungen natürlicher Walddynamiken auf die Artengefüge in Eichenwäldern: Untersuchung von Heterogenitätseffekten am Beispiel epigäischer Raubarthropoden Study course: Ecology, Evolution and Nature conservation (M.Sc.) University of Potsdam presented by Marco Langer 757463 1. Evaluator: Prof. Dr. Monika Wulf, Institut für Landnutzungssysteme Leibniz-Zentrum für Agrarlandschaftsforschung e.V. 2. Evaluator: Tim Mark Ziesche, Landeskompetenzzentrum Eberswalde Published online at the Institutional Repository of the University of Potsdam: URL http://opus.kobv.de/ubp/volltexte/2011/5558/ URN urn:nbn:de:kobv:517-opus-55588 http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55588 Abstract The heterogeneity in species assemblages of epigeal spiders was studied in a natural forest and in a managed forest. Additionally the effects of small-scale microhabitat heterogeneity of managed and unmanaged forests were determined by analysing the spider assemblages of three different microhabitat structures (i. vegetation, ii. dead wood. iii. litter cover). The spider were collected in a block design by pitfall traps (n=72) in a 4-week interval. To reveal key environmental factors affecting the spider distribution abiotic and biotic habitat parameters (e.g. vegetation parameters, climate parameters, soil moisture) were assessed around each pitfall trap. A TWINSPAN analyses separated pitfall traps from the natural forest from traps of the managed forest. A subsequent discriminant analyses revealed that the temperature, the visible sky, the plant diversity and the mean diameter at breast height as key discriminant factors between the microhabitat groupings designated by The TWINSPAN analyses. Finally a Redundant analysis (RDA) was done revealing similar environmental factors responsible for the spider species distribution, as a good separation of the different forest types as well as the separation of the microhabitat groupings from The TWINSPAN. Overall the study revealed that the spider communities differed between the forest types as well as between the microhabitat structures and thus species distribution changed within a forest stand on a fine spatial scale. It was documented that the structure of managed forests affects the composition of spider assemblages compared to natural forests significantly and even small scale-heterogeneity seems to influence the spider species composition. I Abstract................................................................................................................................. I Figures .............................................................................................................................. IV Tables ................................................................................................................................. VII Acknowledgements ............................................................................................................ IX 1 Introduction .................................................................................................................. 1 2 Methods ........................................................................................................................ 4 2.1 Description of the study area ................................................................................... 4 2.2 Site selection and study design ............................................................................... 7 2.3 Data acquisition ....................................................................................................... 9 2.3.1 Invertebrate sampling .......................................................................................... 9 2.3.2 Microhabitat measurements ...............................................................................10 2.4 Data Evaluation ......................................................................................................14 2.4.1 Pitfall traps .........................................................................................................14 2.4.2 Soil samples .......................................................................................................14 2.4.3 Additional evaluation ..........................................................................................15 2.5 Statistical analysis ..................................................................................................16 2.5.1 Species accumulation ........................................................................................16 2.5.2 Dominance .........................................................................................................17 2.5.3 Jaccard and Sørensen coefficient of the community...........................................18 2.5.4 Dominance identity .............................................................................................19 2.5.5 Multidimensional scaling ....................................................................................20 2.5.6 Guild composition ...............................................................................................20 2.5.7 Ecological type ...................................................................................................21 2.5.8 Diversity .............................................................................................................22 2.5.8.1 Shannon-Wiener-Index ................................................................................22 2.5.8.2 Evenness .....................................................................................................23 2.5.9 Rarefaction .........................................................................................................24 2.5.9.1 Hurlbert curve and estimation of α-diversity .................................................24 2.5.10 Spearman´s rank correlation coefficient .............................................................25 2.5.11 Habitat preference and Indicator analysis ...........................................................25 2.5.12 Twinspan analysis ..............................................................................................26 2.5.13 Discriminant analysis ..........................................................................................27 2.5.14 Redundancy analysis (RDA) ..............................................................................27 3 Results .........................................................................................................................28 3.1 Environmental parameters .....................................................................................28 3.1.1 Vegetation ..........................................................................................................28 3.1.2 Dead wood distribution .......................................................................................31 II 3.1.3 Climate of the local population ...........................................................................35 3.1.4 Soil parameters ..................................................................................................37 3.2 Faunistic .................................................................................................................40 3.2.1 Spectrum of species ...........................................................................................40 3.2.2 Species accumulation ........................................................................................44 3.2.3 Dominance .........................................................................................................46 3.2.4 Faunal similarity .................................................................................................46 3.2.5 Multidimensional scaling ....................................................................................48 3.2.6 Guild composition ...............................................................................................51 3.2.7 Ecological type ...................................................................................................53 3.2.8 Shannon- Weaver Diversity/ Evenness ..............................................................54 3.2.9 Rarefaction .........................................................................................................55 3.2.9.1 HURLBERT curve to examine the α-diversity ..............................................55 3.2.10 Species correlation to environmental parameters ...............................................59 3.2.11 Habitat preference of species .............................................................................60 3.2.12 Indicator species analysis ..................................................................................61 3.2.13 TWINSPAN analysis ..........................................................................................63 3.2.14 Discriminant analysis ..........................................................................................65 3.2.15 RDA analysis......................................................................................................68 4 Discussion ...................................................................................................................71 4.1 Relevance ..............................................................................................................71