UC Berkeley

Regenerating forests play a crucial role in climate change mitigation, biodiversity conservation, soil and water protection as well provide several other ecosystem and financial services, while helping compensate for the carbon emitted from deforestation and forest degradation. They in fact serve as a Nature-based Solution (NbS), contributing significantly to forest carbon markets and ecotourism. Nevertheless, climate change – in particular altered precipitation patterns and increased frequency of extreme weather events – poses severe threats to these forests and hinder their growth and resilience. Moreover, anthropogenic stressors, such as deforestation, land conversion, and pollution, further exacerbate these challenges. Unsurprisingly, the impact of these stressors varies across different forest ecosystems. For instance, tropical forests face unique challenges due to their sensitivity to climate variations and require tailored approaches for regeneration as compared to mangroves which have unique adaptations to high temperature and saline environments. Given the limitations of fieldwork – in terms of time, labor, safety, frequency, scalability and cost – there is a need to invest in state-of-the-art remote sensing technologies which can help improve our understanding of the subject.

In this work, I analyzed the impacts of climate, environmental and anthropogenic variables on regenerating forests using GEDI spaceborne LiDAR (Light Detection and Ranging) and moderate resolution satellite remote sensing (Landsat) data, in addition to exploring their role as Nature-based Solutions (NbS) for supporting forest carbon markets and ecotourism sector. In chapter two, I investigated how water availability, forest age, and topographic elevation affect the maximum canopy heights of secondary tropical forests in the Brazilian Amazon utilizing NASA GEDI spaceborne LiDAR data. My results revealed that water availability significantly influences canopy height in 30 to 35 year-old trees at elevations below 500 m and precipitation thresholds up to 1500 mm, with potential implications for forest structure, ecosystem functioning, and carbon sequestration under varying climate conditions. In chapter three, I focused on developing a mangrove forest regeneration age map (using Landsat imagery from 1986-2023) for the GCC (Gulf Cooperation Council) countries and identifying the drivers of successful mangrove afforestation. My results showed that only 8.5% of secondary mangrove forests were older than 30 years, with 41.3% being younger than five years. The key drivers identified included lower elevation, slope, higher soil moisture, lower temperatures, proximity to freshwater sources, lower population density, and greater distance from urban areas. In chapter four, I examined how regenerating forests can serve as NbS and help enhance forest carbon markets and promote ecotourism, while emphasizing the role of remote sensing in providing accurate data on carbon sequestration and improving ecosystem management and conservation. Overall, my research aims to utilize remote sensing methods to advance our understanding of how regenerating tropical forests and mangroves are impacted by various climate, environmental and anthropogenic factors, and how they can serve as effective NbS.