Climate change in the Peruvian Amazon: assessing and modelling the role of invertebrates in wood decay and carbon cycling under changing flood dynamics

Accurately measuring carbon fluxes in tropical forests is important due to their role in understanding and mitigating climate change. However, gaps remain in our understanding of factors affecting wood decomposition, an important component of the carbon cycle (Figure 1). Invertebrates which are a functionally dominant force in tropical forests play a direct role in wood decomposition as well as an interactive role with the microbial and fungal communities which drive wood decay. These factors have never been assessed in the Western Amazon region, which means an important aspect of the global carbon cycle is yet to be fully understood. This project will address this gap in knowledge through a mixture of field experiments and remote sensing.

The forest composition of Western Amazonia is driven by fluvial dynamics, with a difference of 10 metres in height between high water season and low water season. This phenomenon influences the spatial and temporal distribution of termites and hence wood decay processes, leading to seasonal changes in the carbon cycle of the region.

Repeated extreme floods and severe droughts have increased in frequency over recent decades. Modelled future predictions project a consistent amplification of seasonality in precipitation for Western Amazonia. The impact of flooded forest dynamics on termites and hence wood decomposition and carbon cycling has been demonstrated experimentally in other regions, but never in Peru. Therefore understanding how these projected changes in fluvial dynamics in Western Amazonia will impact termites and wood decay processes will increase accuracy of future global carbon cycling models.

This study will use on the ground exclusion experiments and carbon flux monitoring through field work in the Peruvian Amazon to assess the role of termites in wood decay over the flooded forest annual cycle. These observations will be extrapolated to a landscape scale with remotely sensed observations of the extent of flooded forest to model how termite-driven contribution to wood decay and subsequently the carbon cycle will change under predicted climate change scenarios.

This project will involve field work in the Pacaya-Samiria Reserve, Peru. Assessing the functional contribution of termites to wood decay is a standard procedure achieved with wood blocks. These will be placed over representative areas and sub-types of forest, with exclusion experiments used to quantify the mass loss due to termites, microbial and fungal process.

Carbon flux measurements will be taken over the course of the year under different forest types through the annual flood cycle.

Flood monitoring using remotely sensed imagery will be used to assess the spatial coverage and temporal duration of flood pulses and dry seasons.

The results of the exclusion experiments will be used to quantify the changes in wood decomposition, termite activity and carbon cycling over the course of annual flooding. These will then be used to model these processes under current conditions and under future climate scenarios.

The CASE partner is Operation Wallacea who have worked in the Pacaya-Samiria Reserve, Peru for over 10 years, providing a baseline of information on standing wood dynamics and wildlife impacts in which this study can be situated.The local NGO FundAmazonia will be project partners in Peru with Dr Richard Bodmer as the local collaborating scientist. Dr Richard Bodmer is Honorary Professor in Conservation at the University of Kent and has been working in the Amazon for over 30 years.

Dr Kirsten Barrett is an expert in using remotely sensed data to study ecosystem processes such as disturbance recovery cycles, primarily in boreal forest ecosystems as well as tundra and tropical forests. She currently leads a NERC funded project on persistent forest loss following wildfires in Siberia.Dr Moya Burns is an insect community ecologist with expertise in saproxylic fauna and forest insect dynamics. She has worked in the Pacaya-Samiria Reserve, Peru for three years leading long-term monitoring of insect populations in response to changing climate conditions.

Entry requirements
Applicants are required to hold/or expect to obtain a UK Bachelor Degree 2:1 or better in a relevant subject. The University of Leicester English language requirements apply where applicable.

How to apply
Please refer to the CENTA Studentship application information on our website for details of how to apply.

As part of the application process you will need to:
• Complete a CENTA Funding form – to be uploaded to your PhD application
• Complete and submit your PhD application online. Indicate project CENTA2-GGE10-BAR2 in the funding section.
• Complete an online project selection form Apply for CENTA2-GGE10-BAR2