University of Oulu

Cahill, J. R. A., Merckx, T., Van Dyck, H., Fernández, M., and Matthysen, E.. 2021. Lower density of arthropod biomass in small high‐Andes Polylepis fragments affects habitat use in insectivorous birds. Ecosphere 12( 3):e03401. 10.1002/ecs2.3401

Lower density of arthropod biomass in small high‐Andes Polylepis fragments affects habitat use in insectivorous birds

Saved in:
Author: Cahill, Jennifer R. A.1; Merckx, Thomas2,3; Van Dyck, Hans2;
Organizations: 1Centro de Biodiversidad y Genética, Facultad de Ciencias y Tecnología, Universidad Mayor de San Simón, Cochabamba, Bolivia
2Behavioural Ecology and Conservation Group, Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCLouvain), Louvain‐la‐Neuve, Belgium
3Department of Ecology and Genetics, University of Oulu, Oulu, Finland
4Evolutionary Ecology Research Group, University of Antwerp, Antwerp, Belgium
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.4 MB)
Persistent link:
Language: English
Published: John Wiley & Sons, 2021
Publish Date: 2021-03-09


Polylepis forests are endemic to the high‐Andes, with trees characterized by multi‐layered, exfoliating bark‐providing protection against harsh, high‐elevation conditions, both for individual trees and the wide array of organisms dependent on them. However, Polylepis habitat has suffered severe human‐induced land conversion and currently mainly occurs as fragmented remnants only. Here, we studied the effects of fragment size on local ambient temperature and on biomass of bark and its bark‐dwelling arthropods. We did so by comparing multiple samples at the edge and interior of both large and small fragments, while also accounting for branch size, tree width, and tree structure. Because arthropod biomass is likely to impact higher trophic levels, we also studied abundance and foraging behavior of two bird species specialized on Polylepis forest. We show that arthropod biomass was relatively higher in wider, larger trees, which were preferred for foraging by both bird species. Moreover, we show that small forest fragments are not only environmentally less buffered but are also characterized by lower amounts of bark and lower densities of bark‐dwelling arthropods than larger fragments. Our study highlights the conservation value of large trees. Also, we advise it is now timely to test to what degree restoration efforts to increase fragment size could mitigate the negative effects of reduced arthropod biomass for higher trophic levels of endemic specialist insectivores.

see all

Series: Ecosphere
ISSN: 2150-8925
ISSN-E: 2150-8925
ISSN-L: 2150-8925
Volume: 12
Issue: 3
Article number: e03401
DOI: 10.1002/ecs2.3401
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: This study was supported by VLIR‐IUC funding to JC and to the Centro de Biodiversidad y Genética—Universidad Mayor de San Simón.
Copyright information: © 2021 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.