Predicting ecological and evolutionary responses to climate change in habitat and ecological networks: the impact of variation within species

Lead Research Organisation: University of Bristol
Department Name: Biological Sciences

Abstract

Rapid climate change and habitat fragmentation are expected to disrupt ecological interactions between species, even before extinctions due to direct loss of suitable habitat occur. Such disruptions are likely to have serious implications for the services that ecosystems provide for human health and agriculture. In particular, asynchronies are likely to develop in flowering time both between plant populations, and between these plants and their pollinators. These mismatches could substantially reduce both the spatial connectivity of populations, and the ecological resilience of plant-pollinator networks. Attempts to predict such effects assume that traits such as flowering times and flower morphology change little in space and time within a species. However, recent studies of flower traits and emergence time within and between populations reveal very high levels of heritability, which could generate rapid evolutionary change in flower morphology and pollinator visitation. The CASE partner, the Avon Wildlife Trust, has been quick to adopt a 'Living landscape' approach to its conservation to maximise the capacity for species to adapt. Pollination networks on its grassland reserves are already being studied by Dr Michael Pocock (NERC fellow; 2008-11).This studentship will develop a close collaboration between the AWT and the UoB to explore the impact of phenotypic variation and evolutionary change within and between sites of the cowslip, Primula veris, and extrapolate these effects across the reserve network as a whole. Field observations suggest large differences in flower morphology between sites, and in its pollinators, especially when individuals on neutral and calcareous grassland are compared. Flowers are typically pollinated by bee species. P. veris usually flowers for a short period at a site, and produces abundant seed that is typically dispersed close to the parental plant, so detectable neutral genetic differentiation is possible even at small spatial scales (10s of metres). Objectives are: 1.Quantify variation in microclimate, flowering times and morphology within and between reserves in P. veris. Relate this variation to visitation rates by different pollinators, and variation in insect mouthpart size. Assess levels of local adaptation by correlating local microclimate with flowering time, and testing for significant differences between sites (Oct 2010-July 2013) 2.Partition variation in flowering traits into genetic and environmental components. Assess how much of this variation is present between versus within sites, suggesting local adaptation, and confirm fitness effects of this differentiation using reciprocal transplants of seed in the field. (May 2010-July 2012) 3.Estimate current gene flow between plant populations at 15 different sites using 400 AFLP markers and 30 allozyme markers. Relate this to observed levels of overlap in flowering time and pollinator abundance between and within sites. (Aug-May 2010-13). 4.Assess to what extent variation within species and the potential for evolutionary change will affect the generation of asynchrony in flowering time, or maintain ecological networks by causing evolution of flower morphology under different climate change scenarios. Extrapolate these data across larger spatial scales to assess the effectiveness of the 'Living Landscape' networks in generating ecosystem resilience, once within-species variation is included in models (July-Oct 2010-3). Wider significance: Maintaining ecological interactions in the face of global change is a key NERC priority. This will be the first study to estimate genetic and ecological variation in life-history traits in a single species, and assess how maintaining a given networks of distinct habitat reserves is likely to maximise ecological resilience. These data will also inform the value of translocation programmes, which are advocated by some practitioners as critical for conservation in a changing world.

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