Research Update

Dr Cecilia Dahlsjö and Professor Yadvinder Malhi

During the inaugural year of the ash dieback project in Wytham Woods we have been busy setting up and installing equipment and experiments that will enable us to monitor the ecological impact of the fungal disease across the Woods. We have 15 plots spread out across Wytham Woods that act as experimental habitats dedicated to this work.

You may have spotted green mesh traps on stilts about a metre above ground. These are designed to collect fallen litter from which we calculate the rate of litterfall throughout the year. Our soil reparation collars are not far away. These are used to measure monthly carbon emissions from the soil which is linked to root, microbial and insect activity. We have microclimate stations in the centre of each plot, recording climatic data at 10-minute intervals, providing a detailed account of daily and seasonal trends.

In October we started a leaf decomposition experiment which will give us insight into the prospective impact of ash dieback on the litter environment and decomposition rates. We have also set up equipment which allows us to monitor the activity and movements of small mammals, birds, and bats, and we have started monitoring invertebrate and microbial communities using standardised sampling methods. Over the next four years this project will gather data which will enable us to understand how ash dieback will affect nutrient cycling, habitat structure, predation pressure, and woodland connectivity.

Abigail Bailey

Have you wondered what the tent-like structures pitched in the wooded area behind the Wytham Chalet are? Well, these are malaise traps, which capture low-flying insects as well as climbing ground-dwelling species, and funnel them into the chamber at the top of the trap. They are part of the Global Malaise Trap Project that has been set up by the Centre for Biodiversity Genomics in Canada to monitor terrestrial arthropods (invertebrates such as insects and spiders) at research sites across the world.

The project aims to identify the different species at each of these recording sites, using DNA sequencing technology to ‘barcode’ each individual species captured to build up a picture of global invertebrate populations. The data will form a reference database which will help us to fill in the knowledge gap regarding our understanding of the diversity of invertebrate species that currently exists.

The planet is facing catastrophic species decline across all ecosystems and habitats, and our attention is often focussed on the loss of charismatic vertebrate species. However, we are becoming increasingly aware of the ‘quiet extinction’ of invertebrate species globally. There is a concern many invertebrate species will become extinct without us even being aware of their existence.

With invertebrate species playing a crucial role in ecosystem functioning (for example, as food for birds and animals, as well as acting as pollinators and nutrient-cyclers) it is vital that we are able to carefully monitor any changes to invertebrate diversity and species composition which may disrupt the fine balance of global ecosystems with unknown downstream consequences.

Another local site is at Long Mead ancient floodplain meadow in Eynsham. It will be interesting to see the difference in species composition of invertebrates collected at the rare floodplain meadow habitat location and those collected a couple of miles away in the ancient woodland of Wytham Woods.

It is hoped that the participation of each Global Malaise Trap monitoring unit will help to build the jigsaw of our understanding of invertebrate diversity and species composition worldwide, at a time when it is facing great change.