Lasting influences of past land-surface conditions on species assemblages
Terrestrial biodiversity is affected by anthropogenic land change globally. Most land on Earth has been altered by humans at some point in the past, leaving behind landscapes with complex histories. As we continue to change the land, local biodiversity might therefore be influenced not only by the conditions at the time of biodiversity sampling, but also by past land change. Local biodiversity can be affected by past land change through so called “carry-over” and “biotic lag” effects. The effects of the short-term past on biodiversity might thus exacerbate existing effects of land change during sampling conditions, which however has rarely been quantified likely because of a lack of knowledge about the past.
Satellite data can provide internally consistent information on how land has changed in the short-term past. In this study, we combine a global dataset of local biodiversity records with temporal profiles of remotely-sensed indicators. This allows us to assess land changes in the short-term past that occurred before biodiversity was sampled. We then compared these temporal profiles between sites of biodiversity recording and estimated the difference in effect between the short-term past and the period reflecting sampling conditions on biodiversity estimates.
Our results show that biodiversity in the present is more affected by differences in the short-term past than by conditions one year before biodiversity sampling. However we find large differences between taxa and functional groups. Our investigation highlights the importance of historical land change on biodiversity and has implications for conservation planning and ecological models, which may consider to take the effect of past land change into account.