EMMA · Enhancing Mangrove restoration through Microtopographic Analysis

Mangroves are tropical forests located at the land–sea transition that deliver vital ecosystem services, including carbon sequestration and coastal protection. To reverse decades of deforestation, global interest in mangrove restoration has grown, yet more than half of projects fail. This low success rate is linked to insufficient understanding of the fine-scale topographic and hydrological conditions that govern seedling establishment and survival. Tidal mudflats, where restoration typically occurs, are not uniformly flat but shaped by microtopographic features such as creek levees and ridge–runnel systems. Previous research has only assessed suitable topography at large scales (hundreds of metres to kms), overlooking these features. Aerial imagery suggests that natural mangrove expansion aligns with microtopographies, but this has never been systematically studied. This represents a critical knowledge gap, as microtopographies may provide sheltered, elevated niches that enhance propagule retention, seedling survival, and growth. The objective of EMMA is to investigate how microtopographies control mangrove establishment and survival, and whether they can initiate biogeomorphic feedbacks that expand suitable habitat over time. I hypothesize that (1) early expansion aligns with microtopographic features such as creeks and ridges, (2) survival depends on topographic, hydrological, and morphological conditions shaped by these features, and (3) colonization of microtopographies initiate positive feedbacks that facilitate further establishment. I will combine UAV-based LiDAR and hyperspectral surveys with field experiments and biophysical modelling to quantify the role of microtopographies in seedling establishment and growth. The outcomes will provide a scientific basis for adaptive restoration strategies that target high-potential microtopographic areas, increasing survival rates, reducing costs, and improving the long-term success of global mangrove restoration.