Detecting the signature of environmental change in partially observed ecological networks
In the face of rapid and widespread environmental change, developing a thorough understanding of ecosystems and the species and interactions within them is vital to conservation and management. Characterising ecosystems through network structure and dynamics enables an understanding of how different components of ecosystems interact, how these interactions influence stability of communities, and how ecosystems might be conserved (Harvey et al., 2017). This project will use network analysis of a forest ecosystem in combination with a long-term Lepidopteran data set to develop an understanding of ecological dynamics in a temperate rainforest ecosystem.
Forest ecosystems are vulnerable to the effects of climate change, in addition to other pressures including logging and grazing. Scotland’s temperate rainforest is a rare ecosystem in the UK today, requiring further study and conservation efforts. Lepidoptera, particularly moths, are an important component of terrestrial ecosystems, playing vital roles as herbivores, prey, and pollinators, and potentially acting as indicators of ecosystem condition (Bachand et al., 2014). Changes in moth diversity and species composition over time have been documented in the UK, and could provide indications of wider ecological change (Coulthard et al., 2019). The study of trophic and pollination networks incorporating moths provides important insight into the structure and stability of forest ecosystem networks.
Long-term ecological monitoring is important to understand how ecosystems change over time, particularly in light of climate change. Combining long-term ecological monitoring with network-level analyses could provide a powerful method of detecting and predicting ecological change. The Rothamsted Insect Survey has had a light trap collecting macro moths at the Scottish Centre for Ecology and the Natural Environment (SCENE) since 1968, creating a valuable long term data set on moth abundance and diversity spanning more than 50 years. During this time, close to half a million moths across 369 species have been collected. Ecological data over such a long time-series is uncommon and provides a valuable opportunity to examine changes and fluctuations in an important ecosystem, the ancient oak woodland around Loch Lomond. Analysis of these data in 2003 found increasing species richness and changes in phenology of some species (Salama, Knowler & Adams, 2007). However, there has as yet been little opportunity to examine how these changes may have affected or been driven by the wider ecosystem.
This project will characterise the current ecological networks comprising trophic interactions, seed dispersal, and pollination relationships involving Lepidoptera and the organisms directly linked to them in the ecosystem, together with their dependencies on woodland vegetation phenology.
The project is organized around two primary objectives:
1) To characterise the trophic network of the temperate rainforest around Loch Lomond that is centred on Lepidoptera
2) To use historical data on one trophic level (moths) in combination with models of the structure of the current network to make inferences about the structure and dynamics of the network in the past, providing insight about how the wider ecosystem may have changed.