Linking biotic attack with tree mortality & canopy condition in droughted tropical rainforest

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Geosciences


We propose an international network to explore this key knowledge gap in understanding the effects of pests and pathogens in accelerating tropical rainforest tree mortality during drought. The project will deliver an integrated and focused anlaysis, using expertise in plant physiology, forest ecology and microbial and insect ecology. It will also make use of the unique leverage of the world's only long-term drought experiment network in tropical forests. We will use field-based workshops at two current tropical forest drought experiments, in Australia and Brazil, to bring together experts in plant function, the effects of pest and pathogen ('biotic') attack on woody tissue, and vegetation modelling. New ground-based and remotely-sensed measurements will be examined to test for relationships between measures of biotic attack and metrics of plant function during experimental drought. We will compare responses in different tree size classes, tree species groups, and at the level of the forest ecosystem (large experimental plot treatment).

The outcome will be new insights into the causes of tropical rainforest tree death from drought, in relation to plant physiology and insect or microbial attack. This insight will be delivered in the form of new data, new scientfic articles and information that can be used by vegetation modellers to predict the effects of drought on tropical forests in the future.

The group of experts built using these funds will form a pre-eminent multi-disciplinary consortium in the subject area, capable of advancing the subject into the future for the benefit of the science, interested environmental policy makers and university educators.

Planned Impact

We propose to build a team to explore the relationships between new measures of biotic attack in the stem and canopy of droughted rainforest trees, with mesurements of their physiological function and with their risk of drought-related mortality (as quantified using current NERC support).

The outcomes and impacts will be (i) new multi-disciplinary datasets; (ii) at least two papers (a review and a new-data paper) and new insights to support model development; and (iii) a unique consortium ready to address large emerging science opportunities (UK, EU, global) with significant potential impact on international environmental policy and natural resource management.

This proposal will generate new collaborations with experts globally (USA, Australia, Europe, Brazil). It adds substantial novelty to NE/J011002/1 upon which it builds, but without which it would not be feasible. It comprises an advanced scoping and synthesis study to address a key gap in understanding of the climate vulnerability in tropical forests, and will enable testing and standardisation of a powerful but new combination of methods. The international partners bring specific new expertise and capability and the outcomes will include synthesis and comparative papers, and a unique multi-disciplinary group with substantial future funding leverage.

We envisage long term impacts as this group will be the first to address the question of tropical rainforest vulnerability to drought in this integrated way. We expect to deliver unique research capacity and insight through the testing of new methods, transferring that information into modelling contexts and expanding a key research area that has lagged plant ecological research but is now recognised as potentialy key to understanding how future climates may affect rainforest functioning and diversity in the coming century.

Our outputs will have wide potential impact, used by: (i) the ecological science community; (ii) the Earth system modelling community; (iii) the ecosystem services analysis community; (iv) policy making bodies such as government departments and international development banks (eg. IDB); and (v) conservation bodies and related interest groups.
Description We do not yet have synthesised results as the project workshops have is only recently been completed. We are working on the data collected so far. We have substantially extended the use of new equipment to address our limited knowledge of tree internal cavities in relation to taxon, climate and climate stress and this will extend our initial goals in a useful and productive way.
Key findings to date include: (i) first evidence of biotic attack in trees stems resulting from drought; (ii) evidence of significant differences i ncanopy structure following long term drought; evidence of signficant differences in hyperspectral reflectance properties of droughted vs non-droughted canopy tree leaves. These data will be worked up into papers in the coming months; the paper deliver process will reflect the investigative nature of this grant, as post doc could be funded on it (as is normal with IoF grants).
Exploitation Route We hope that the new information from this grant will be ground-breaking in that few other groups, if any, have considered how to quantify pest and pathogen damage in the way we are trying to. We hope this will build expertise to allow further work in this important area, that may hold one of the keys to understanding how drought leads to death in rainforest trees. Our findings in 2018 (data analysis so far) suggest that we have identified a clear signal of biotic attack in droughted rainforest trees; we will work further on this in the coming months.
Sectors Agriculture, Food and Drink,Education,Environment,Government, Democracy and Justice,Culture, Heritage, Museums and Collections

Description They have been used in communication activities with the local collaborative partner in Brazil - this provides increased awareness and helps with building 'societal' support for the research. The second regional partner, in Australia, James Cook University has also been fully engaged. A full second international workshop was held in autumn 2018, where the range of planned measurements was delivered. We now have datasets on canopy structure, soil condition and termite abundance, on tree stem condition and, individually for the Australian site, leaf reflective properties. Our workshop series completed with plans for more than one paper using the above data.
Sector Education,Environment
Impact Types Cultural,Societal