Wildlife-friendly farming benefits rare birds, bees and plants

Abstract

Agricultural intensification is a leading cause of global biodiversity loss, especially for threatened and near-threatened species. One widely implemented response is 'wildlife-friendly farming', involving the close integration of conservation and extensive farming practices within agricultural landscapes. However, the putative benefits from this controversial policy are currently either unknown or thought unlikely to extend to rare and declining species. Here, we show that new, evidence-based approaches to habitat creation on intensively managed farmland in England can achieve large increases in plant, bee and bird species. In particular, we found that habitat enhancement methods designed to provide the requirements of sensitive target biota consistently increased the richness and abundance of both rare and common species, with 10-fold to greater than 100-fold more rare species per sample area than generalized conventional conservation measures. Furthermore, targeting landscapes of high species richness amplified beneficial effects on the least mobile taxa: plants and bees. Our results provide the first unequivocal support for a national wildlife-friendly farming policy and suggest that this approach should be implemented much more extensively to address global biodiversity loss. However, to be effective, these conservation measures must be evidence-based, and developed using sound knowledge of the ecological requirements of key species.

Figure 1.

The number (±s.e.) of rare and common (a) plant and (b) bumble-bee species, and (c) Hedge's d (±95% CIs) comparing bird species number, recorded on general and evidence-based habitats with a cereal crop control. Species richness of common and rare plants was highest on evidence-based habitats and similar between general and control habitats (common, F_2,76 = 112.39, p < 0.001; rare, F_2,76 = 17.16, p < 0.001). The same pattern was seen for species richness of common and rare bumble-bees, except that common bees were also more diverse on general than control habitats (common: F_2,73 = 75.38, p < 0.001; rare: F_2,73 = 6.70, p < 0.01). Common and rare bird numbers were higher (signified by d > 0) in the evidence-based habitat compared with both the general habitat and the control, and the latter two treatments had similar numbers (d was not significantly different to 0). White bars represents common species, grey bars represents rare species.

Figure 2.

Poisson regressions of rare species richness recorded on evidence-based habitats against richness of rare species in the surrounding 10 × 10 km square for (a) plants, (b) bumble-bees and (c) birds. The fitted relationship is shown for cases with a slope significantly greater than 0 (i.e. plants and bumble-bees). Dashed lines indicate 95 % CIs. The χ² and significance of the slope are given, along with the χ²/d.f. ratio of the full model. A value less than 2 for this ratio indicates good model fit. A jitter has been applied to the points for clarity. Data for rare species comprised post-1970 occurrence records held by the UK Biological Records Centre.