Quantifying the Consequences of Spatio-temporal Dynamics of Mangroves Forests in the Provision of Ecosystem Goods and Services

Quantifying the Consequences of Spatio-temporal Dynamics of Mangroves Forests in the Provision of Ecosystem Goods and Services

Ecosystems

Office of Research and Development (ORD), Center for Public Health and Environmental Assessment (CPHEA)

Research Triangle Park, NC

12 months

Mangrove forests provide important ecosystem goods and services to the world’s dense coastal population and support important functions of the biosphere. The forests are under threat from both natural (e.g. typhoons, sea level rise) and anthropogenic forces (rapid economic development, population growth). The loss of these ecosystems can lead to the loss of critical functions of mangroves including coastal protection, carbon sequestration and biodiversity—thus threatening the resiliency and vitality of coastal social-ecological systems. However, our scientific understanding is limited in regards to the rates, patterns and causes of changes to mangrove forest cover and their impact in providing ecosystem goods and services. The proposed research aims to examine dynamics of mangrove forests and associated change in ecosystem good and services of from 1985 to present.

All available time series of Landsat TM, ETM+, and OLI and Sentinel-2 imagery will be pre-processed to generate surface reflectance products. Pre-processing steps include Top of Atmosphere (ToA) reflectance conversion, cloud/haze removal, and surface reflectance conversion. Landsat and Sentinel-2 data will be the major data sources for the mangrove forest cover change analysis supplemented by very high-resolution satellite data (e.g. WorldView, GeoEye) and field inventory data. Random forest algorithm will be used for image classification. The Continuous Change Detection and Classification (CCDC) and the Vegetation Change Tracker (VCT) and Support Vector Machine (SVM) algorithms will be used to map mangrove forest conversion, disturbance, and regrowth on an annual basis. Extensive fieldwork will be required to collect ground truth for identifying the causes of mangrove change and validating Landsat/Sentinel-2 imagery-derived change. The very high-resolution satellite imagery (<5 m resolution) will complement on-the-ground data collection for the accuracy assessment.

We will conduct a rigorous large-scale evaluation of the drivers of mangrove loss and the effectiveness of current conservation practices (e.g. protected areas) at conserving mangroves and reducing blue carbon emissions. Specifically, we will apply quasi-experimental techniques (combining propensity score and covariate matching, differences-in-differences, and post-matching bias adjustments) to assess whether current management practices prevented mangrove loss between 1985 and 2015, building on recent work on the effects of protected areas on mangrove loss in Indonesia by one member of the proposed research team and colleagues (Miteva, Murray and Pattanayak, 2015).

To value the protection services provided by mangroves in sheltering coastal communities from extreme weather events, such as typhoons, we will (i) compare the damages measured in terms of household properties and assets, agricultural assets, and number of deaths in coastal villages with thinner mangrove cover compared to villages with relatively thicker mangrove cover; and (ii) estimate the economic value of storm surge damages in coastal communities with different mangrove areas, densities, species, and disturbance regime. We will use the damage-cost approach (Barbier and Enchelmeyer, 2014) in valuing the protection services provided by mangrove ecosystems against storm related damages. This method takes into account the actual damages brought by the super typhoon in areas with mangrove forests compared to the damages in areas without mangrove forest.

We will compile the species-specific information on distribution, population status and major threats for each of the mangrove birds, mammals and amphibian species. Each species’ probability of extinction will be assessed under the Categories and Criteria of the IUCN Red List of Threatened Species. Spatio-temporal analysis will be performed to examine the impact of mangrove forest cover change and forest fragmentation to these species. Particular areas of biodiversity concern in Southeast Asian mangroves will be identified.

As part of our effort to quantify the role of mangrove forest fragmentation on biodiversity, we will calculate metapopulation capacity for species endemic to mangrove forests. We will use an occupancy based, spatially explicit metapopulation (SEM) model that has been modified to include self-colonization term in order to prioritize large, contiguous patches (Schnell et al., 2013). This model works by estimating a population's extinction risk as a function of patch size as well as the colonization rate from all nearby occupied patches. The colonization rate increases with patch size and decreases with inter-patch distance. With this model, we can estimate the metapopulation capacity of a landscape to determine the likelihood of long-term persistence of a species given the spatial arrangement of mangrove fragments.

Specific objectives are:

1. Develop a methodology to detect and monitor mangrove forests’ status and dynamics (conversion, modification and disturbance) using earth observation satellite data on an annual basis; identify the rates, patterns and causes of mangrove forests cover conversion, modifications and disturbances.
2. Quantify and, where possible, monetize the role and value of mangrove forests in providing ecosystem goods and services including carbon sequestration, storm protection and biodiversity conservation, and explore economic potential for conserving mangroves based exclusively on their ecosystem goods and services.
3. Assess efficacy, at large spatial scales, of mangrove restoration projects in generating mangrove ecosystems and the services they provide.
4. Enumerate the changes in ecosystem goods and services in the past ~30 years, and project for the next 50-100 years.

The GRIP intern will have the opportunity to:

• Work with researchers from diverse background coming from government, academia and the private sector.
• Take a leadership role in their area of expertise or interest.
• Play an active role or primary authorship role in publishing peer reviewed publications.
• Present research results at national and international conferences.
• Network with leading scientists from around the world.
• Take a leading role in preparing proposals.

Chandra Giri, giri.chandra@epa.gov