Maria Rachelle Gallmann
Crab Community state and activity in typhoon Haiyan hit mangrove forests in Bantayan Island, Cebu, Philippines (completed June 2016; Cum Laude)
Mangrove crabs (primarily of the families Sesarmidae and Ocypodidae), due to the effects of their activities on propagule consumption, leaf litter, and burrowing, are considered important ecosystem bio-engineers in mangrove forests. Therefore, the crab communities may play an important role in the recovery process of mangroves disturbed by a typhoon such that of Typhoon Haiyan. The thesis will examine the crab community characteristics (abundance, diversity, size/weight) and activity (burrowing and feeding) in mangrove sites in Bantayan Island with different gradients of typhoon damage. As the site consists of both natural and planted mangrove stands, a comparison of the crab community between these stands will also be made.
Christine Ghie Legaspi
An Assessment of the Post-typhoon Correlation of Mangrove Seedling Regeneration and Sediment Characteristics in Bantayan Island, Cebu (completed June 2016)
Typhoon Haiyan brought storm surges and strong currents that greatly damaged the mangrove forests as well as the coastal communities depending on its ecosystem services. This study will evaluate post-typhoon mangrove recovery by examining the relationship of mangrove seedling regeneration and sediment status. Seedling regeneration will be measured through species abundance and diversity, survival and growth rate. Sediment properties that will be measured will include grain size, organic matter, temperature, pH, salinity, and redox. Data will be compared between planted and natural mangroves to test the hypothesis that natural mangrove stands recover faster than the planted mangrove stands.
Using microbial community structure and activity as soil regeneration indicator in mangroves damaged by Typhoon Haiyan (completed June 2016; Magna Cum Laude)
The microbial communities in tropical mangrove ecosystems form the base of the mangrove food chain and continuously cycle essential nutrients and dissolved organic matter to make it available to higher organisms. Thus, there is a close relationship among microbial communities, nutrients and mangrove plants. In recent years, extreme weather events have been a cause of the destruction of mangrove ecosystems. This thesis seeks to use microbial community structure and enzymatic activity as indicators of soil regeneration in mangroves damaged by Typhoon Haiyan.
Anne Brigitte Lim
(Part-Time) Research Assistant (completed December 2015)
Using the 210Pb dating method to evaluate the sedimentation rate and adaptation of Philippine mangroves against sea level rise
Sediment accumulation of a mangrove area may be traced back on a 100-year timeline using the 210Pb dating method. However, this approach has not yet been implemented on studies of mangrove ecosystems in the Philippines. This thesis will test the hypotheses that sediment accretion matches sea-level rise at four mangrove sites of the Philippine Islands that were hit by Super Typhoon Haiyan. Sediment accretion rate will be measured by using the 210Pb dating method. The results of this method will be validated by determining the 137Cs concentration of the samples. To test the hypothesis, sedimentation rates will be compared to local rates of sea-level rise to determine the forests’ adaptation (or vulnerability) to keep pace with sea-level rise.