TY - JOUR

T1 - Tree species identity, canopy structure and prey availability differentially affect canopy spider diversity and trophic composition

AU - Wildermuth, Benjamin

AU - Dönges, Clemens

AU - Matevski, Dragan

AU - Penanhoat, Alice

AU - Seifert, Carlo L.

AU - Seidel, Dominik

AU - Scheu, Stefan

AU - Schuldt, Andreas

N1 - Funding Information: We thank Christian Ammer and Serena Müller for project organization, and the foresters of the RTG 2300 sites for collaboration. We thank Michael Hohner, Theo Blick, Simeon Indzhow, Tobias Bauer, Alexander Bach and Isabell Scheibert for helping during spider identification. We are grateful for methodological advice from Jochen Drescher and Jens Dyckmans. Funding Information: Open Access funding enabled and organized by Projekt DEAL. This study was funded by Deutsche Forschungsgemeinschaft (DFG) under the grant number 316045089/GRK 2300. Publisher Copyright: © 2023, The Author(s).

PY - 2023/10

Y1 - 2023/10

N2 - Forest canopies maintain a high proportion of arthropod diversity. The drivers that structure these communities, however, are poorly understood. Therefore, integrative research connecting tree species identity and environmental stand properties with taxonomic and functional community composition of canopy arthropods is required. In this study, we investigated how the taxonomic, functional and trophic composition of arboreal spider communities is affected by tree species composition and associated differences in canopy structure and prey availability in temperate forests. We sampled canopy spiders as well as their potential prey using insecticidal fogging in monospecific and mixed stands of native European beech, native Norway spruce and non-native Douglas fir. Trophic metrics were obtained from stable isotope analysis and structural canopy properties were assessed with mobile laser scanning. Monospecific native spruce stands promoted local canopy spider abundance and diversity, but native beech and beech–conifer mixtures had the highest diversity at landscape scale. Spider community composition differed between monospecific stands, with broadleaf–conifer mixtures mitigating these differences. Irrespective of tree species identity, spider abundance, taxonomic diversity, functional richness and isotopic richness increased in structurally heterogeneous canopies with high prey abundances, but functional evenness and trophic divergence decreased. Our study shows that canopy spiders are differentially affected by tree species identity, canopy structure and prey availability. Broadleaf–conifer mixtures mitigated negative effects of (non-native) conifers, but positive mixture effects were only evident at the landscape scale. Structurally heterogeneous canopies promoted the dominance of only specific trait clusters. This indicates that intermediate heterogeneity might result in high stability of ecological communities.

AB - Forest canopies maintain a high proportion of arthropod diversity. The drivers that structure these communities, however, are poorly understood. Therefore, integrative research connecting tree species identity and environmental stand properties with taxonomic and functional community composition of canopy arthropods is required. In this study, we investigated how the taxonomic, functional and trophic composition of arboreal spider communities is affected by tree species composition and associated differences in canopy structure and prey availability in temperate forests. We sampled canopy spiders as well as their potential prey using insecticidal fogging in monospecific and mixed stands of native European beech, native Norway spruce and non-native Douglas fir. Trophic metrics were obtained from stable isotope analysis and structural canopy properties were assessed with mobile laser scanning. Monospecific native spruce stands promoted local canopy spider abundance and diversity, but native beech and beech–conifer mixtures had the highest diversity at landscape scale. Spider community composition differed between monospecific stands, with broadleaf–conifer mixtures mitigating these differences. Irrespective of tree species identity, spider abundance, taxonomic diversity, functional richness and isotopic richness increased in structurally heterogeneous canopies with high prey abundances, but functional evenness and trophic divergence decreased. Our study shows that canopy spiders are differentially affected by tree species identity, canopy structure and prey availability. Broadleaf–conifer mixtures mitigated negative effects of (non-native) conifers, but positive mixture effects were only evident at the landscape scale. Structurally heterogeneous canopies promoted the dominance of only specific trait clusters. This indicates that intermediate heterogeneity might result in high stability of ecological communities.

KW - Araneae

KW - Arboreal arthropods

KW - Functional diversity

KW - LiDAR

KW - Mixed-species forestry

KW - Trophic niche

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=85171286672&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/d7f074b6-232a-3589-9e57-bf11cc12c7fa/

U2 - 10.1007/s00442-023-05447-1

DO - 10.1007/s00442-023-05447-1

M3 - Journal articles

C2 - 37709958

AN - SCOPUS:85171286672

VL - 203

SP - 37

EP - 51

JO - Oecologia

JF - Oecologia

SN - 0029-8549

IS - 1-2

ER -