Interactions between sources of environmental change: How do resource quality and coloured environments drive multi-trophic eco-evolutionary dynamics?

Environmental variation is in all natural ecosystems. Understanding how it affects individuals within a species, changes their population size and interactions between species is the bedrock of ecology. Seasonal patterns in weather, periods of drought or flooding and large-scale regional climate changes, such as El Niño, are examples of environmental variation across the world. Given the future impacts of climate change on biodiversity, this fundamental ecological process is now an incredibly important and urgent issue for scientists and society. Recent climate warming has resulted in a range of species responses, such as latitudinal and altitudinal shifts in the geographic distribution of populations and changes in the timing of key life cycle events, which may increase extinction risks. For example, El Niño events are increasing in frequency, which will have a dramatic impact on biodiversity across large regions of the world. These changes in environmental variation will affect our ability to predict how species and their interactions will respond to climate change, with important implications for the management of natural populations, such as fisheries and biological pest control.
Changes in environmental conditions can be thought of in a similar way to the different colours in the visible light spectrum. Rapid environmental changes dominate in "blue" environments (short wavelengths are most important in blue light); slow changes dominate in "red" environments (long wavelengths are most important in red light); "white" environments are random; an equal mixture of fast and slow changes. We will focus on how species respond to two sources of environmental variation that may interact with each other; fluctuations in temperature (specifically the colour of those fluctuations), a key driver of species' responses to climate change, and variation in food quality, which is a measure of environmental degradation. We will study the impact of these environmental changes on the relationship between an insect and a parasitic wasp in lab experiments. The insect is a pest around the world, so we will learn about how pest species will respond to climate change. Parasitic wasps are a highly diverse group of organisms that play a crucial role in ecological communities and in regulating insect crop pests. As well as informing us about how predators and prey respond to environmental variation generally, we will learn whether this might lead to more pest problems in the future. Laboratory systems have been used to answer questions in ecology and evolution that are extremely difficult to address in the field. When combined with mathematical models, as we propose to do, they have greatly improved our understanding of invasion, biological control and harvesting.
The theory underlying the impact of environmental variation on biodiversity has received considerable attention recently, but we will develop this theory to more accurately reflect the biology of many species. Some species only reproduce once a year (the focus of previous theory), but many others reproduce continuously throughout the year (the focus of this study), facing constantly changing conditions within and across seasons. We are also interested in whether environmental change will affect important traits of species, such as how long they take to develop or if their body size changes, and how those changes affect their abundance. To fully understand these continuously reproducing populations that may be adapting to environmental change, we have to develop new mathematical approaches. We will develop the theory of environmental variation and link this to our laboratory system. We will study whether environmental variation causes potentially unexpected patterns in population size and whether it will change the risk of species going extinct. The novel experiments will test how well the models work, improving them by updating them with the new information from the experiments.

Who will benefit?
The primary users of this project will be the academic community, particularly empirical and theoretical biologists in the areas of biodiversity, population ecology and evolution, community ecology and invasion biology. The novel mathematical models we develop will provide a general framework that can be applied to a wide range of study systems, from molecules, genes, neurones, individuals, populations, communities, spatial patches and ecosystems. The mathematical theory of coloured noise in continuous-time equations will be of interest to the wide range of academics involved in the study of stochastic processes (engineering, physics, mathematics, economics). Additionally, by studying pests and their natural enemies, our work has the potential to benefit those involved in applied science nationally and internationally, particularly entomologists and industry involved in the risk assessment and development of biological control agents of economically important pests in horticulture and agriculture. This aspect of our project will likely be promoted as a result of Leeds being a member of the N8 Universities, which have combined resources to focus on sustainable agriculture. The reduction of crop yields by pests and how this will be impacted by climate change is a major concern in the broad field of food security, especially in light of increasingly strict control over the use of chemical pesticides. Thus, our work may also add to the body of scientific information that could be used by policy makers concerned with sustainable agricultural intensification. As a result of NERC-funded work, SMS engaged with policy makers in the EU as a member of the EFSA working group developing guidance for the release of GM insects in Europe. The Department of Biosciences at Swansea University is developing collaborative links with the Royal Agricultural University. These links will allow us to share the outcomes of this work directly with relevant academics and, through their networks, policy developers and other non-academic beneficiaries. The project will also be of interest to the public with concerns about climate change, conservation and for those whom Lepidoptera are a charismatic species. We also expect our work to be of interest to organisations such as FERA (land use, biological control), land managers and other bodies involved in environmental stewardship.
How will they benefit?
Understanding how species will respond to climate change and environmental variation more generally will reveal important links between species and our environment and help explain why some species become pests, why some invade or alter their ranges. These processes are threats to biodiversity and major challenges to ecologists, land managers and policy makers. Although this project may not lead directly to recommended changes in species or habitat management that may mitigate against future changes in the environment, it will provide one more piece of the jigsaw by revealing the potential response of communities to changes in the spatio-temporal structure of environmental variation (e.g. currently occurring with El Niño). Our proposal will deepen our understanding of this issue and so be of great academic and applied interest. This project provides a framework for disseminating information on environmental change impacts more broadly, a subject that can be made enticing for an applied and general audience, particularly in the areas of ecosystem service provision in agricultural landscapes, the biological control of pests and the sustainable intensification of agriculture. SMS and MSF have strong track records of publishing their research in general science/ecology/pest control journals, thereby maximising the reach of their work and demonstrating their ability to write for non-specialist audiences. The links with the Royal Agricultural University will also enable us to identify and develop partnerships with key non-academic stakeholders.