Impacts of habitat fragmentation in a warming world

Global warming is now an undeniable reality, with species range shifts, seasonal shifts in life cycle events, and reduced body size recognised as three universal responses to increasing temperature. The Intergovernmental Panel on Climate Change has forecast an average 1.5-4.5 C increase in global surface temperatures, with even stronger increases predicted for Arctic areas. In addition, the small species pool and geographic isolation of high latitude ecosystems makes them particularly vulnerable, with recent suggestions that they may act as early-warning indicators to the potential impacts of global warming. At the same time, humans are exerting great change on natural ecosystems, with habitat fragmentation recognised as one of the major threats to biodiversity. Agricultural expansion to meet growing global food demands has seen natural landscapes divided up into smaller, and more isolated fragments by monocultures of commercially important crops. My research will study the interaction of these two major components of global change and the effect they have on terrestrial communities. I will determine the manner in which natural communities assemble - a critical process in harvested ecosystems, which are continually reset to early stages of succession. I will then assess how warming and fragmentation alter this process and how detrimental that might be to the ecosystem services we derive. I will also determine the impact of warming and fragmentation on the structure of terrestrial food webs, with a particular interest in how loss of larger predators may undermine pest control in agricultural systems. This will have important implications for crop yield and quality. I will assess the resilience of these communities to extreme events, by simulating severe flooding in my study systems. And I will improve our predictability of warming impacts on terrestrial ecosystems by testing predictive models with the data I collect. The findings will help to inform conservation management in the face of continuing global change, as well as agriculture and land use policy, and our general understanding of how natural communities respond to climatic and human-induced disturbances.

The following four sectors are the most likely non-academic beneficiaries of this research:
(1) Agricultural bodies in the UK, such as the Agriculture and Horticulture Development Board (ADHB) and the Home Grown Cereals Authority (HGCA), which support and advise the Department for Environment, Food, and Rural Affairs (DEFRA).
(2) Conservation bodies, such as Natural England, the Environment Agency, and the Wildlife Trusts in the UK, and Landvernd, the Icelandic Environment Association.
(3) Energy companies in Iceland, such as the National Energy Authority of Iceland (Orkustofnun) and Reykjavik Geothermal Limited.
(4) The general public, including UK schools, farmers, and ecotourism.

The field experiment at Silwood Park will examine the impact of warming and habitat fragmentation on grain yield and quality. This research is directly aligned with many of the goals of the HGCA, which also financially supports similar research programmes to help inform government agricultural policies through the ADHB and DEFRA. The findings may also contribute to future food security in the UK and internationally, by informing cereal farmers how to maximise their crop through promotion of biological control of pests. This approach may also promote successful organic farming over the use of pesticides, which can be harmful to the environment and human health.

The research at both Silwood Park and Hengill, Iceland may also help conservation bodies mitigate against the impacts of future global change, by making informed decisions about potential ecosystem-level impacts of habitat fragmentation, warming, and flooding. The development of models predicting the impact of warming and habitat isolation on food web structure will be particularly relevant to planning for and managing future environmental change. Environmental agencies in Iceland will also have baseline data on the ecological importance of geothermal areas to inform geothermal energy companies about the destructive potential of expansion, particularly for ecotourism - one of the country's largest industries.

Outreach activities will ensure the research informs and inspires a younger generation of environmentalists. Science exhibitions at the Natural History Museum and the Royal Society's headquarters in London provide the opportunity to interact directly with families and young adults. Media coverage will also transmit the research findings to as broad an audience as possible (see Pathways to Impact for full details).