Advances in Microclimate Ecology Arising from Remote Sensing

This paper reviews the use of remote sensing in detecting microclimates in forests. We look into how we could combine remotely sensed data along with data from weather stations to map microclimates in forests in great detail, highlighting some opportunities they provide for ecology, conservation and climate change research.

Zellweger, F.; De Frenne, P.; Lenoir, J.; Rocchini D.; Coomes D.A.

Trends in Ecology & Evolution
2019

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Airborne laser scanning of natural forests in New Zealand reveals the influences of wind on forest carbon

This study shows that forests in New Zealand facing in the direction of westerly storms are shorter and store less carbon than more sheltered forests. However, these forests develop the highest carbon density for a given height when compared with 14 other tropical forests studied using the same approach, suggesting that although wind kept these forests short, it has not impeded basal area growth. The study also found that models based on top-of-canopy height are almost as accurate as complex tree-centric approaches in estimating forest carbon.

Coomes, D.A.; Šafka, D.; Shepherd, J.; Dalponte, M.; Holdaway, R.

Forest Ecosystems 5 (1), 10
2018

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Canopy structure and topography jointly constrain the microclimate of human‐modified tropical landscapes

Local‐scale microclimatic conditions in forest understoreys play a key role in shaping the composition, diversity and function of these ecosystems. Consequently, understanding what drives variation in forest microclimate is critical to forecasting ecosystem responses to global change, particularly in the tropics where many species already operate close to their thermal limits and rapid land‐use transformation is profoundly altering local environments. Yet our ability to characterize forest microclimate at ecologically meaningful scales remains limited, as understorey conditions cannot be directly measured from outside the canopy. To address this challenge, we established a network of microclimate sensors across a land‐use intensity gradient spanning from old‐growth forests to oil‐palm plantations in Borneo. We then combined these observations with high‐resolution airborne laser scanning data to characterize how topography and canopy structure shape variation in microclimate both locally and across the landscape. In the processes, we generated high‐resolution microclimate surfaces spanning over 350 km2, which we used to explore the potential impacts of habitat degradation on forest regeneration under both current and future climate scenarios. We found that topography and vegetation structure were strong predictors of local microclimate, with elevation and terrain curvature primarily constraining daily mean temperatures and vapour pressure deficit (VPD), whereas canopy height had a clear dampening effect on microclimate extremes. This buffering effect was particularly pronounced on wind‐exposed slopes but tended to saturate once canopy height exceeded 20 m—suggesting that despite intensive logging, secondary forests remain largely thermally buffered. Nonetheless, at a landscape‐scale microclimate was highly heterogeneous, with maximum daily temperatures ranging between 24.2 and 37.2°C and VPD spanning two orders of magnitude. Based on this, we estimate that by the end of the century forest regeneration could be hampered in degraded secondary forests that characterize much of Borneo’s lowlands if temperatures continue to rise following projected trends.

Jucker, T.; Hardwick, S.R.; Both, S.; Elias, D.M.O.; Ewers, R.M.; Milodowski, D.T.; Swinfield T.; Coomes, D.A.

Global change biology 24 (11), 5243-5258
2018

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Larger fragments have more late‐successional species of woody plants than smaller fragments after 50 years of secondary succession

In 1959, a dam was constructed in Zhejiang, China, creating the Thousand Island Lake with isolated islands of different sizes that were originally hilltops. The vegetation on these isolated patches has been undisturbed since the construction of the dam and gradually gone through succession into secondary forests. In this study, we show that the patch size was an important predictor of forest succession, with larger patches accumulating more late succession species and smaller patches remaining in earlier stages of succession.

Liu, J.; Coomes, D.A.; Hu, G.; Liu, J.; Yu, J.; Luo, Y.; Yu, M.

Journal of Ecology
2018

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Assessing the Progress of REDD+ Projects towards the Sustainable Development Goals

Almost a decade since the establishment of Reducing Emissions from Deforestation and Degradation (REDD+), this study investigates the extent to which REDD+ projects are delivering on the promise of co-benefits and the elusive ‘triple-win’ for climate, biodiversity, and local communities. The Climate, Community and Biodiversity Alliance (CCB) is among several leading REDD+ certification standards that are designed to support the delivery of social and environmental co-benefits, and ‘socially-just’ carbon. This study uses an in-depth content analysis of 25 subnational REDD+ project documents to assess the extent to which REDD+ project objectives align with Sustainable Development Goals (SDG) targets, and evaluates the reporting of progress towards meeting these objectives. Currently the CCB standards address a relatively small subset of SDG targets. Despite this, we find that REDD+ projects aspire to work on a much broader set of SDG target objectives, thus going beyond what the CCB Standards require for REDD+ validation. However, although reviewed REDD+ projects have these aspirations, very few are actively monitoring impact against the goals. There is a gap between aspiration and reported progress at the goal level, and for each project: on average, only a third of SDGs that are being targeted by REDD+ projects are showing ‘improvement’. The analysis shows which global goals are most frequently targeted, and which are the least. It also allows an analysis of which projects are following through most effectively in terms of monitoring progress towards the SDGs. This assessment provides insights into the priorities of REDD+ project proponents, suggesting that REDD+ has unfulfilled potential to elicit positive change in relation to the SDGs. Our analysis also shows that there is considerable potential for the safeguarding bodies to do more to ensure that real improvements are made, and reported against, aligning REDD+ projects more strongly with global development agendas.

Milbank, C.; Coomes, D.A.; Vira, B.

Forests 9 (10), 589
2018

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