Effects of crop management at the landscape scale on biodiversity : a review and research perspectives
Résumé
Agricultural activity, through farming practices and landscape changes, is an important driver of
biodiversity and ecosystem service provision. While the relationship between land-use and biodiversity
is widely studied, few studies consider the "hidden" heterogeneity of agricultural landscapes represented
by crop management. Indeed, most species living in agroecosystems are affected by the intensity and
spatial distribution of farming practices, which can be as—or even more—influential as the diversity of
crops and non-crop habitats. The objective of our review is to assess 1) how crop management was
described at the landscape scale and 2) the estimated effects on biodiversity and potential of ecosystem
service provision. According to a Web of Science request, we retrieved 133 original studies dealing with
the broad notion of crop management at the landscape scale and rejected studies only considering landcover and land-use metrics. Three components of crop management are studied in analyzed papers:
effect of agricultural system (i.e., organic vs. conventional farming), effect of crop rotation, and effect of
individual farming practices (e.g., soil tillage, pesticide or nitrogen use). Natural enemies, insect pests,
pollinators, birds, and weeds are the primary organisms for which the effect of crop management at the
landscape scale has been studied. Overall, preliminary results show that many studies examine the
effect of a single component of crop management (in most cases, the effect of organic farming) and do
not compare the effects of crop management at the local and landscape scales. Extensiveness of crop
management in the landscape seems to benefit biodiversity and the provision of ecosystem services.
While expansion of organic farming in the landscape benefits to pollinators and weeds, diversification
of rotation has positive effect on bird. Individual farming practices have shown species and practicesdependent effects, suggesting that the direction of effect is not obvious and deserves to be studied. Our
findings suggest that the interest for crop management in the landscape needs to be reinforced in
ecological studies. A better knowledge of their impact on biodiversity would allow intensifying the joint
landscape-scale management of both heterogeneities of land use and crop management.