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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: David Coomes, Plant Sciences

Co-Supervisor: Emily Lines, Geography

Brief summary: 
Large areas of degraded pastureland in the Southern Alps are being taken out of agricultural production and allowed to passively rewild, but the effectiveness of this government policy remains poorly understood. Working with local partner Manaaki Whenua Landcare Research and involving extensive field work alongside remote sensing, the project will quantify how landscapes that undergoing passive restoration following agricultural abandonment are evolving. Using time-series of multispectral imagery, the recovery of native woody vegetation will be tracked through time, comparing rewilded sites with matched regions that remain under grazing management. The significance of recovering forest fragments as carbon sinks will be evaluated and compared with carbon dynamics in intact native woodlands. This study is pertinent to global conservation in the UN's decade of restoration.
Importance of the area of research concerned: 
New Zealand’s unique flora and fauna is under threat from multiple pressures. Woodland clearance by settlers reduced the extent of native vegetation causing large-scale biodiversity. Now vast areas of human-created grasslands in the Southern Alps, that were used as extensive pastureland over the past century, are being allowed to rewild passively. However, the trajectory of natural ecosystem recovery remains poor understood in these montane systems. A combination of remote sensing technologies and field approaches are needed to fill this knowledge gaps. The UN has declared the 2020s as the decade of restoration, recognising the global imperative to reverse biodiversity decline and mitigate climate change by using natural systems are carbon stores. Given the international impetus, there has never been a more important moment for developing a scientific understanding of restoration processes.
Project summary : 
Large swaths of degraded pastureland in the Southern Alps have been purchased by the government and allowed to rewild, but the effectiveness of this policy remains poorly understood. Nature’s recovery is largely passive, as few resources are available for active restoration, but the trajectory of change is poorly quantified. Using time-series of multispectral imagery, the recovery of native woody vegetation will be tracked through time, comparing rewilded sites with matched regions that remain under grazing management. The significance of recovering forest fragments as carbon sinks will be evaluated using NASA’s GEDI data (measurements of forest structure from space), and compared with carbon dynamics in intact native woodlands. The possibility of using hyperspectral imagery to assess woodland compositional changes will also be explored.
What will the student do?: 
Working closely with biologists and remote sensing scientists at Manaaki Whenua Landcare Research, NZ’s largest conservation and environmental research organisation, the student will collect field data and analyse high-resolution imagery to track changes over time and evaluate the drivers of woodland recovery. * Using multispectral imagery, the recovery of native woody vegetation to high country regions will be tracked through time. * NASA’s GEDI will be used to evaluate the carbon stocks in regenerating woodlands. One possibility is to compare the carbon sink in the restoration area with that in the intact forests around Wellington, where detailed maps of forest carbon over 8049-km2 of land are available thanks to an airborne lidar survey conducted in 2013. * Extensive field surveys will be conducted to quantify the recovery not only of plants but also of poorly documented taxa, such as the soil biota. These data will be used to evaluate drivers of recovery (e.g. topographic position and proximity to remnant native bush). * The possibility of mapping woody species composition in these regenerating woodland using hyperspectral imaging will also be explored
References - references should provide further reading about the project: 
Mason et al. (2013) Functional Traits Reveal Processes Driving Natural Afforestation at Large Spatial Scales https://doi.org/10.1371/journal.pone.0075219
Young et al. (2016) One hundred years of vegetation change at Cass, eastern South Island high country, New Zealand Journal of Ecology 40. https://doi.org/10.20417/nzjecol.40.38
Coomes et al. (2020) Airborne laser scanning of natural forests in New Zealand reveals the influences of wind on forest carbon. Forest Ecosystem 5. https://doi.org/10.1186/s40663-017-0119-6
Applying
You can find out about applying for this project on the Department of Plant Sciences page.
Dr Emily Lines
Department of Plant Sciences Graduate Administrator
David Coomes