The study, which modelled different varieties of natural land-cover loss, showed that the pattern in which natural land cover is lost is as important as the amount of loss itself.

"We need to manage both natural land cover loss and fragmentation," said Matthew Mitchell of the University of Queensland, Australia. "We often don't think about how the structure of a landscape impacts ecosystem service provision. Our study shows that we can't just conserve natural land cover and ecosystems, and assume that this will automatically maximize service provision. We also have to understand how the spatial location of those ecosystems will impact ecosystem services."

The loss of natural land cover is a theme of growing interest among researchers. Recent studies have shown that more than 70% of the world's forests are within one kilometre of an edge, and the effects have often been negative. For example, the abundance and diversity of species, as well as certain ecosystem processes like nutrient retention and pollination, have fallen.

Land-cover loss often happens in a fragmentary fashion, but until now we knew little about the effect of different levels of fragmentation. When clearing a certain amount of natural land cover for fields, for example, it's possible to clear one big, standalone patch, or to clear many smaller patches – and this choice could be crucial for the provision of pollination, pest regulation, human recreation and other ecosystem services.

Mitchell, who carried out the research with colleagues whilst at McGill University, Canada, modelled seven different patterns of land-cover loss that increased in fragmentation level. The researchers assumed that the "flow" of ecosystem services was greater in a patch of modified land the closer it was to a fragment of natural land cover.

"Pollinators, especially insect pollinators, often use natural ecosystems like forests or meadows as [their] habitat, and then disperse from these places into fields," explained Mitchell. "The farther you get from these habitats, the fewer pollinators or pest predators you encounter, which can reduce the amount of [the] ecosystem service provided."

The researchers found that, in general as the natural land cover dropped, there came a threshold point when ecosystem services dropped suddenly. More surprisingly, however, the study showed there was a "tradeoff" between the conservation of natural land cover and the maximization of ecosystem services – in other words, that some loss of natural land cover, with attendant fragmentation, actually improved the ecosystem services.

"Returning to the pollination example, in this case managing the landscape to have an intermediate level of fragmentation might maximize pollination over a landscape structure that has a single large patch of forest or one that has lots of very small patches," said Mitchell.

The team reported their findings in Environmental Research Letters (ERL).