Climate change and the phenology of moths and their hostplants in England and Wales

Abstract

The impact of Global Climatic Change (GCC) on the phenology of species has been well established. Consequential impacts of altered phenology on the interactions in an ecosystem has been hypothesised, with some evidence of species decline as a result. However, the drivers of phenological changes are less well understood, knowledge of which could be key to predicting the impacts of GCC on phenology of organisms in the future, and the potential impacts on ecosystem functioning. In this thesis, this contribution seeks to determine the drivers of moth phenology and their hostplants in England and Wales, whether their phenology varied in space, and whether their phenology was losing synchrony. To achieve this data was obtained from the National Moth Recording Scheme, Garden Moth Scheme, Woodland Trust Nature’s Calendar, and Met Office. Linear Mixed Effects (LME) models were used to analyse phenological shifts for 149 moth species and 132 plant species, followed by an in-depth analysis of four moth species and five hostplants using Integrated Nested Laplace Approximations (INLA). Overall, the LME analyses found a significant difference in the phenology of moths and plants with different life history strategies, with a consistent impact of temperature on phenological shifts. The INLA analyses demonstrated spatial variation in moth phenological shifts, but there was no spatial variation in the hostplant phenology, and only Spilosoma lutea had a significant spatial relationship with its hostplant Hedera helix. These findings demonstrate that large scale phenological studies should consider how species with different life history traits may respond to GCC. Further, as S. lutea is a pupa overwintering polyphagous species, this highlighted that species with generalist diets may still be impacted by GCC and should not be discounted from studies on phenological asynchrony.