Niche Properties of Central European Spiders: Shading, Moisture and the Evolution of the Habitat Niche

• Published in: Global ecology and biogeography Vol. 16; no. 4; pp. 440 - 448
• Main Authors: Entling, Wiebke, Schmidt, Martin H., Bacher, Sven, Brandl, Roland, Nentwig, Wolfgang
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing 01.07.2007; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Araneae; Biogeography; Biological and medical sciences; Biological taxonomies; correspondence analysis; Ecological genetics; Ecological niches; environmental gradients; Forest habitats; Fundamental and applied biological sciences. Psychology; General aspects; General aspects. Techniques; Generalities; Habitat conservation; habitat specialization; habitat types; indirect gradient analysis; niche position; niche width; Species; Spiders; Synecology; Wildlife habitats; Europe; Biogeography; niche width; Araneida; Shading; Ecology; habitat specialization; Araneae; spiders; indirect gradient analysis; Arachnida; Specialization; Correspondence analysis; habitat types; Arthropoda; Humidity; Ecological niche; Habitat; niche position; Invertebrata; Width; environmental gradients
• ISSN: 1466-822X; 1466-8238
• DOI: 10.1111/j.1466-8238.2006.00305.x

Aim: Niche theory emphasizes the importance of environmental conditions for the distribution and abundance of species. Using a macroecological approach our study aimed at identifying the important environmental gradients for spiders. We generated numerical values of niche position and niche width. We also investigated relationships between these niche properties as well as the degree of phylogenetic conservatism in order to draw conclusions about the evolution of the habitat niche. Location: Central Europe: lowlands of Austria, Belgium, Germany, Luxembourg, the Netherlands and Switzerland. Methods: We analysed 244 published spider communities from 70 habitat types by correspondence analysis. The resulting community scores were used to test for correlations with habitat characteristics. Species scores were used to derive niche position (mean scores) and niche width (standard deviation of scores). To test for niche conservatism we estimated variance components across the taxonomic hierarchy. Results: The first two axes of the correspondence analysis were correlated with shading and moisture, respectively. Niche width had a hump-shaped relationship to both environmental gradients. β-diversity was strikingly higher in open habitats than in forests. Habitat niche conservatism was lower than phylogenetic conservatism in body size. Main conclusions: Environmental factors are important drivers for the β-diversity of spiders, especially across open habitats. This underlines the importance of preserving the whole range of moisture conditions in open habitats. Narrow niches of species occurring at the ends of both environmental gradients indicate that adaptations to extreme habitats lead to constraints in ecological flexibility. Nevertheless, the habitat niche of species seems to evolve much faster than morphological or physiological traits.