Biodiversity-ecosystem functioning (B-EF) research has been dominated by studies at relatively small spatial and short temporal scales and by experiments in artificially established plant or animal communities. However, real-world ecosystem functioning is also driven by processes at larger spatial scales (e.g. landscape) and it remains unclear to what extent these large-scale mechanisms modify B-EF-relationships. To fill this gap of knowledge, we tested effects of species and landscape-element diversity on ecosystem functioning at the landscape scale using a comparative study design across Switzerland (Central Europe).
Species diversity measures were derived from a national biodiversity monitoring programme that provided species inventories for vascular plants, butterflies and breeding birds for 520 plots 1-km² in size. Landscape-element diversity metrics were derived from land cover point data provided by the Federal Statistical Office. Ecosystem functioning indices were derived from remotely-sensed data (MODIS EVI) and included vegetation activity and land surface phenology including growing season length. All data cover at least a decade, and we thus also were able to test for effects on the stability of these indices.
Results/Conclusions
Our results show that the diversity of landscape elements (including Shannon's diversity, patch richness and edge density of land cover) is positively related to total and individual species diversity of plants, butterflies and birds in Swiss landscapes. The effect of plants and birds was stronger than the one of butterflies, which seem to be related to altitude effects. Furthermore, landscape-scale diversity appears to be a significant driver of land surface phenology. Landscape-element as well as plant species diversity appeared to significantly prolong the vegetation growing season length, mainly by an earlier start of the season but also to some extent by a postponed end of the season. The resistance of vegetation activity to a severe drought in 2003 and stability expressed as 1/CV over the 2000-2015 period was significantly enhanced by both landscape-element and plant species diversity.
Our results demonstrate that diversity effects on real-world ecosystem functioning and stability at the landscape scale are significant and stress the crucial role of landscape-element diversity as an important factor of species diversity and ecosystem functioning.