(MERI) Does biodiversity restoration enhance the capacity of ecosystem functions to buffer climate extremes?

The role of species diversity as a driver of ecosystem stability - or the ability of an ecosystem to maintain a relatively stable state in the face of environmental fluctuations - has a long history in ecology. Indeed, numerous studies show that high plant species richness increases the stability of ecosystem functions, such as plant production, and their capacity to resist and recover from abrupt perturbations, such as climate extremes, which are increasing in intensity and frequency with climate change1. The mechanistic basis for such relationships is still open to debate, but it is mostly put down to the insurance hypothesis2: put simply, high levels of plant diversity provide an insurance against declines in ecosystem functioning following a perturbation, such as a drought; while some species fail, others are able to resist and/or rapidly recover, thereby stabilizing ecosystem function. The importance of understanding how plant diversity influences the stability of ecosystem functions couldn’t be more relevant than it is today: ecosystems are being increasingly challenged by extreme events, such as droughts and heat waves, and, as such, there is an increasing need to come up with ways to mitigate against them. One possible way of achieving this is through the enhancement of botanical diversity in agricultural grasslands, which for many years has been a major goal of European Agricultural Policy. We have shown in our past work that grassland diversity restoration can bring additional benefits for various ecosystem functions and services, such as soil carbon storage and nutrient retention3,4. But it remains unclear whether biodiversity restoration also enhances the stability of ecosystem functions, such as plant production and nutrient cycling, and their capacity to resist and recover from extreme weather events.

This studentship will redress this gap in understanding by exploring the mechanisms by which grassland diversity restoration influences the stability of ecosystem functions of key importance for both agricultural production and environmental protection. The student will test the hypotheses that increased plant diversity as a result of restoration management enhances the temporal stability of ecosystem functions, such as plant production, nutrient retention, and greenhouse gas fluxes, and their capacity to resist and recover from extreme weather events, especially drought. This will be tested using a long-term (25 year) grassland biodiversity restoration experiment at Colt Park Meadows, Ingleborough National Nature Reserve in the Yorkshire Dales3, and an extensive network of grasslands of varying management intensity across England5. The student will use a combination of long-term records of plant production in diversity restoration treatments, combined with experimental testing of the stability of various ecosystem functions over annual and inter-annual timescales, and of their resistance and resilience to simulated drought to identify mechanisms involved.

The student will be trained in the measurement of multiple ecosystem functions and in advanced statistical methods for assessing data. The student will have access to world-class facilities in the Soil and Ecosystem Ecology Laboratory at The University of Manchester, which houses state-of-art facilities for the analysis of soil nutrient and carbon dynamics, soil organisms and ecosystem processes, including greenhouse gas fluxes. The student will also have access to brand new, state of the art growth facilities at Firs Experimental Station, including glasshouse and controlled environment chambers. The student will join a large team of researchers, including postgraduate students and postdoctoral scientists, within the Soil and Ecosystem Ecology Laboratory, and a team of scientists and conservationists working at Colt Park on different aspects of grassland management for multiple ecosystem services and biodiversity conservation.