PHD Project

October 10, 2023

Biodiversity for woodland resilience: the long-term functional ecology of tree diversity

Woodland scenes

The benefits of biodiversity for forest resilience and delivery of many ecosystem services underpin “nature-based solutions”. However, there are major gaps in knowledge of the ecological mechanisms, leading to serious over-generalisation and weak evidence base for policy and management. Resilience of European woodlands is threatened by climate-change-linked escalation of catastrophic tree pathogens and pests. We recently found striking results that (i) diversity of neighbouring trees (lower proportion of conspecifics) can increase ash susceptibility to dieback disease, which challenges ecological theory; (ii) trajectory of tree-species composition in unmanaged semi-natural ancient woodland is rapidly diverging from site-environment predictions, through differential species’ performance mediated by invasive-species and disturbance impacts. To advance fundamental scientific knowledge and the evidence-base for management of resilient woodland ecosystems, this project will address four research questions:

  1. What is the relative effect on tree recruitment, growth and survival of species identity, functional traits or relative size/distance/crown-position of neighbouring trees?
  2. How do these tree-neighbourhood effects interact with site environment and disturbance regime/pathogens/browsing?
  3. How are these diversity effects influenced by the spatial scale of tree species mixing?
  4. What is the relative importance of (i) small- and (ii) larger-scale ecological interactions and (iii) landscape-scale mixed-species portfolio, for a resilient woodland resource delivering both biodiversity conservation and climate-change mitigation?

To address these questions, we have an unprecedented opportunity to use two long-term-ecological-research, National-Nature-Reserve woodland sites: Lady Park Wood, Monmouthshire (longest-monitored (since 1945) and most-accurately tree-mapped set of woodland permanent sample plots (PSP)); Coed Dolgarrog, Conwy (PSPs stratified across woodland types, scheduled for 20-year re-enumeration in 2025). The research will combine standard PSP re-measurement with high-tech, including terrestrial laser scanning/rangefinder; leaf-level gas-exchange; digital-image analysis of mammal herbivory; modelling of tree-neighbourhood, disturbance and invasive-species impacts. Multidisciplinary scenario development and analysis will be used to draw-out evidence for resilience management and policy.

Eligibility.

Enthusiastic and academically-able graduates from a wide range of environmental, biological and geographical degree subjects are eligible for this project. If in doubt get in touch for a chat.

Email address for enquiries.

j.healey@bangor.ac.uk