PhD defence: Kenneth Grogan

Kenneth Grogan defends his PhD thesis:

  

Tropical forest monitoring in Southeast Asia using remotely sensed optical time series - forest transformation and the impact of natural rubber plantations

  

Supervisors

Associate Professor Rasmus Fensholt, IGN

Professor Patrick Hostert, Humboldt-Universität

  

Assessment Committee

Associate Professor Martin Rudbeck Jepsen, IGN (chair)

Professor Lars Eklundh, Dept. of Physical Geography and Ecosystem Science, Lund University

Professor Martin Herold, Wageningen UR, Environmental Sciences  

  

After the PhD defence there will be a reception in ‘Rød stue’, Øster Voldgade 10, Area 6, First floor – and everybody is welcome.

Summary

Despite the importance of tropical forest ecosystems, they continue to be transformed at an alarming rate. In Southeast Asia, the historical deforestation narrative of a growing population gradually encroaching upon forest land is being replaced by the dominating influence of large-scale plantations. In particular, the global demand for natural rubber (Hevea brasiliensis) has been reported as the cause of widespread forest conversion. A critical component of forest conservation strategies, such as Reduced Emissions from Deforestation and forest Degradation (REDD+), relies upon the monitoring of forest cover using satellite remote sensing technology. This PhD research explores the utility of optical satellite imagery to monitor forest loss and conversions to natural rubber plantations in Southeast Asia, with a specific focus on Cambodia in the post-2000 era. By using Landsat and MODIS satellite imagery coupled with advanced time series analysis, Cambodia’s forest cover was found to be experiencing rapid change, with a gross forest cover loss of 24%. Forest clearance rates tripled after 2010 compared to the early 2000s, suggesting the country is at the initial phase of the forest transition curve. Forest-to-rubber conversions were estimated to be responsible for 20% of total forest clearances, and annual forest-to-rubber conversion rates were found to be highly correlated to global rubber prices at local and national scales. Although global rubber markets can be linked to forest cover change, the effects of land policy in Cambodia, and beyond, have also played a major role in the transformation process.

 

The thesis is available from the PhD administration office 04.1.417