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This study poses the question of whether putting the focus solely on species diversity may overlook other aspects related to the responses of biological communities.

Daniel Montoya, researcher at the Theoretical and Experimental Ecology Station in Moulis, France, and leader of this study, explained to us: “Human actions challenge nature in many ways. Ecologists and practitioners tend to assess the impact of human activities on biodiversity only by measuring the extinction rates of species. However, biodiversity comprises elements other than single species, such as the interactions among species and their stability over time and space.”

“These additional, sometimes overlooked properties are key for the functioning of ecosystems”, he added. “They are the missed component of biodiversity loss that accompanies or precede species extinctions”.

Interactions between species are lost faster than the species themselves

Despite biodiversity changes beyond species extinctions being previously reported, the authors of this study did not expect the substantial changes that habitat loss imposes on the stability of natural communities. Their results support theoretical and empirical findings showing that interactions among species are lost faster than the species themselves. In addition, they suggest that habitat loss affects the stability of biological communities, that is, the temporal and spatial variability of population biomasses. The magnitude of these responses is mediated by changes in how dominant species interact with each other within the remaining habitat.

This study also found that the way habitat is lost is key for the response of biodiversity. Natural habitats can be destroyed randomly or in a clustered way – for example, by the construction of a road or the creation of new urban areas. The spatial configuration of the loss differentially constraints the mobility of individual animals, which further impacts biodiversity and the stability of populations in the remaining fragments of intact habitat. This leads them to question the way habitat is destroyed in real landscapes around the world. The authors showed that it depends on the spatial scale we are looking at. They explored several scenarios of habitat loss and their results suggests that community responses are approximately gradual and predictable.

This study also relates with recent research exploring changes in local diversity fostered by global change, currently under a hot debate. “We suggest that, irrespective of a positive, negative or neutral change in local diversity, the spatial pattern of habitat loss largely influences the structure and dynamics of biodiversity in very different, contrasting way” said M. Lurgi (Swansea University, U.K), co-author in the study.

Finally, these results can help environmental science and policy maker. The researchers suggests that conservation efforts focusing on alleviating the effects of natural habitat loss would benefit from including several aspects of community structure and stability, in addition to species persistence, into assessment and management plans, and urge for the integration of the type of spatial configuration of habitat loss into conservation planning, as it can strongly determine the response of communities.