Findings from a new scientific study, released today by the Countryside Survey Partnership, show that the total effect of changes to small patches of land over a number of years could be one of the factors in the decline of pollinating insects such as bees.
The Countryside Survey Integrated Assessment report examines the status and trends of ecological processes that have value for individuals or society within Great Britain. Headline messages from the report concern different ecosystem services, including pollination, soils, and the quality of freshwaters and their relationship with biodiversity.
The analysis reveals that between 1990 and 2007 the number of wild plant species that provide nectar for bees has decreased, in small patches of semi natural habitat. These small but highly significant changes combine to make a total reduction in the areas supporting wild nectar providing plants that pollinators rely on.
Environment Secretary, Caroline Spelman, said:
“Pollinating insects are vital to our existence, helping to provide the food on our tables. It is important that we investigate the causes of the decline and take action to address it. The UK has some of the best environmental scientists in the world and using their skills we are gathering more information on changes to our land and the effects this has on species and habitats. This survey will help us analyse what effects policy decisions have and where and how we need to take action.”
Lead author of the Integrated Assessment, Dr Simon Smart from the Centre for Ecology & Hydrology, said:
“Quantifying ecosystem services and understanding the interactions between them provides a significant challenge for scientists, one which we’re only just developing techniques to investigate. This new analysis, possible because of a unique national dataset, delivers, for the first time, evidence that key global change phenomena such as air pollution and land use change have affected delivery of ecosystems services across the British countryside over the last two decades. As well as measuring different services, such as pollination, we’ve also determined possible causes of changes in services over time, and even modelled what might happen under a number of ‘what if’ scenarios.”
The report concludes that the decline is mainly due to nectar providing plants being crowded out by the growth of more competitive plant species. This overgrowth may be related to reduced management and air pollution where the deposition of nitrogenous compounds from the air acts like a fertilizer. In one habitat type - streamside margins - this reduced management has had benefits for freshwater quality, indicating the importance of not considering single ecosystem benefits in isolation.
The in-depth study of the habitats, soils and landscape features was carried out by scientists using specially developed electronic recording tools and web-enabled data systems to improve the efficiency of data collection. Many of the same sites have been monitored for each survey since 1978, but additional sites have been added in each survey to improve estimates of change in specific geographical areas.