Agricultural landscapes that contain a wider diversity of land-use types support invertebrates with a broader range of roles in the ecosystem, finds a study in Nature Communications. This suggests that maintaining diverse landscapes may be more important for the functioning of agricultural ecosystems than the effects of small-scale farmland intensification.
Different species within an ecological community may share similarities in some of their biological traits, such as the way that they disperse or their capacity to reproduce. It is known that communities with a wider diversity of traits provide better functioning of ecosystems - for example, more efficient cycling of nutrients - and may also be better able to cope with environmental change, since greater diversity means a higher probability of key organisms surviving disturbance.
David Perovic and colleagues study this diversity by collecting more than 36,000 invertebrates representing almost 600 different species from agricultural landscapes in Germany, measuring how traits shared by members of the community are affected by the landscape in which they are found. They find that areas characterised by low diversity in land use (the proportion of forests, grasslands and farms in an area) and highly intensive agriculture are dominated by larger invertebrates that are much less-specialised in their feeding habits.
Simplification of the landscape mosaic and increased farm-scale intensification therefore act as ecological 'filters' by allowing only these larger, generalist species to persist, thereby making the invertebrate community more homogeneous in the types of functions it can provide. These findings imply that it is likely that key specialist functions provided by smaller invertebrates, such as pollination of specific plants, will be lost in simpler landscapes, and suggests that management regimes aimed at enhancing ecosystem functioning would benefit more from increasing the diversity of the landscape than simply reducing intensification on farms.
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