Summary
This study reviewing the drivers of population change over 400 species and three taxonomic groups in the United Kingdom (U.K.) finds that intensive agricultural management (e.g. livestock grazing) and climate change are the strongest contributors to population changes, whether those impacts be negative or positive. Using IUCN Red List and E.U. Habitats and Bird Directives data, agricultural management is found to have a predominantly deleterious effect on species richness and diversity, of high significance given agriculture’s status as accounting for the largest percentage of impact. Conversely, low-intensity management of agricultural land and habitat creation had the greatest positive impact on species populations. A strength of the study is the allowance for conclusions broad enough to make results applicable over many species, places, and time. A limitation is the study of drivers of change in isolation, due to knowledge gaps about how the drivers interact with each other, as they are expected to do. Implications of the study include a need to restructure agricultural practices and food production in a way that is conducive to conservation of biodiversity, namely through changes to existing and future public policy.
Action to reduce anthropogenic impact on the environment and species within it will be most effective when targeted towards activities that have the greatest impact on biodiversity. To do this effectively we need to better understand the relative importance of different activities and how they drive changes in species’ populations. Here, we present a novel, flexible framework that reviews evidence for the relative importance of these drivers of change and uses it to explain recent alterations in species’ populations. We review drivers of change across four hundred species sampled from a broad range of taxonomic groups in the UK. We found that species’ population change (~1970–2012) has been most strongly impacted by intensive management of agricultural land and by climatic change. The impact of the former was primarily deleterious, whereas the impact of climatic change to date has been more mixed. Findings were similar across the three major taxonomic groups assessed (insects, vascular plants and vertebrates). In general, the way a habitat was managed had a greater impact than changes in its extent, which accords with the relatively small changes in the areas occupied by different habitats during our study period, compared to substantial changes in habitat management. Of the drivers classified as conservation measures, low-intensity management of agricultural land and habitat creation had the greatest impact. Our framework could be used to assess the relative importance of drivers at a range of scales to better inform our policy and management decisions. Furthermore, by scoring the quality of evidence, this framework helps us identify research gaps and needs.