Press release: Mosaic landscapes enhance functional diversity of animals

Nr. 244/2015 - 21.10.2015

Agroecologists from Göttingen University find that landscape diversity compensates intensive land use practices

(pug) Conserving biodiversity is essential for ensuring sustainability of natural, semi-natural and managed systems. Management and policy presently focus on local actions, but the ecological processes that govern community diversity operate at much larger scales. This means that local management strategies may be ineffective if the surrounding landscape is not supportive of biodiversity. Extended areas of single land-uses across the landscape are perhaps the most serious threat to biodiversity, more so than intense management in production systems.

Although pollination is most commonly emphasized when speaking of arthropod biodiversity, arthropods (mostly insects and spiders) represent an essential component in other ecosystem functions, including biological control and nutrient recycling. Conservation of their biodiversity is therefore essential for ecosystem function and sustainability, in managed as well as in nature systems. However, studies which consider the arthropod community as a whole are rare. As part of the DFG Biodiversity Exploratories Project, a recent study lead by Dr. Catrin Westphal from the Agroecology group at the University of Göttingen focused on entire arthropod communities inhabiting managed grasslands across Germany, a study unprecedented in community size and spatial scale.

The work tracked changes in species characteristics within communities in different landscape and in-field management scenarios. In-field management actions aimed at increasing grassland productivity – fertilizer inputs, grazing intensity and mowing frequency – have been shown to affect the local diversity of well-studied arthropods, such as pollinators. Intense management, coupled with landscape simplification, strongly homogenizes arthropod communities and reduces the diversity present in the community and therefore its ability to respond to future changes in land-use or climate.

“Conservation management and policy need to be focused on landscape-level patterns and on ensuring a diversity of land-uses surrounding managed fields. This offers the potential to increase sustainable intensity in agricultural landscapes even in the face of future global change,” says Dr. Westphal.

“In the face of continued global changes – in land-use pressure and climate – it is especially important to conserve communities which are functionally diverse, rather than just have high species numbers. It is important that the species found in the community fill different niches and have different life-history characteristics to increase what’s called response diversity, so that the community can cope if and when these changes occur,” says Dr. David Perović, a co-author of the study.

The study demonstrates that although in-field management intensity can strongly homogenize arthropod communities, these effects are dependent on landscape context, especially the diversity of surrounding land-uses. The effectiveness of local actions to encourage arthropods can be strongly mitigated by the landscape settings that surround managed fields, which means that the focus of management and policy should be scaled up to address these processes.

“The homogenization related to intense in-field management can be strongly mitigated by landscape complexity, thus conserving function diversity and more sensitive species,” adds the study’s lead author Dr. Sagrario Gámez-Virués. “Management and policy need to be extended to this scale in order to be effective in conserving functional diversity and those more sensitive species, and therefore offer sustainability.”

Original publication: Sagrario Gámez-Virués et al. (2015). Landscape simplification filters species traits and drives biotic homogenization. Nature Communications. Doi: 10.1038/ncomms9568.

Contact:
Dr. David Perović
Fujian Agriculture and Forestry University
Institute of Applied Ecology
Fuzhou, Fujian, China
Email: davidjperovic@outlook.com

Dr. Catrin Westphal
University of Göttingen
Faculty of Agricultural Sciences - Agroecology
Grisebachstraße 6, 37077 Göttingen
Phone: +49 0551 39-22257
Email: cwestph@gwdg.de
Web: www.uni-goettingen.de/en/agroecology/74726.html