Rozainah Binti Mohamad Zakaria

Projecting Global Mangrove Species and Community Distributions under Climate Change

Given the multitude of ecosystem services provided by mangroves, it is important to understand their potential responses to global climate change. Extensive reviews of the literature and manipulative experiments suggest that mangroves will be impacted by climate change, but few studies have tested these predictions over large scales using statistical models. We provide the first example of applying species and community distribution models (SDMs and CDMs, respectively) to coastal mangroves worldwide. Species distributions were modeled as ensemble forecasts using BIOMOD. Distributions of mangrove communities with high species richness were modeled in three ways: as the sum of the separate SDM outputs, as binary hotspots (with >3 species) using a generalized linear model, and continuously using a general boosted model. Individual SDMs were projected for 12 species with sufficient data and CDMs were projected for 30 species into 2080 using global climate model outputs and a range of sea-level rise projections. Species projected to shift their ranges polewards by at least 2 degrees of latitude consistently experience a decrease in the amount of suitable coastal area available to them. Central America and the Caribbean are forecast to lose more mangrove species than other parts of the world. We found that the extent and grain size, at which continuous CDM outputs are examined, independent of the grain size at which the models operate, can dramatically influence the number of pseudo-absences needed for optimal parameterization. The SDMs and CDMs presented here provide a first approximation of how mangroves will respond to climate change given simple correlative relationships between occurrence records and environmental data. Additional, precise georeferenced data on mangrove localities and concerted efforts to collect data on ecological processes across large-scale climatic gradients will enable future research to improve upon these correlative models.

Long-Term Assessment of an Innovative Mangrove Rehabilitation Project: Case Study on Carey Island, Malaysia

Wave energy and storm surges threaten coastal ecology and nearshore infrastructures. Although coastal structures are conventionally constructed to dampen the wave energy, they introduce tremendous damage to the ecology of the coast. To minimize environmental impact, ecofriendly coastal protection schemes should be introduced. In this paper, we discuss an example of an innovative mangrove rehabilitation attempt to restore the endangered mangroves on Carey Island, Malaysia. A submerged detached breakwater system was constructed to dampen the energy of wave and trap the sediments behind the structure. Further, a large number of mangrove seedlings were planted using different techniques. Further, we assess the possibility of success for a future mangrove rehabilitation project at the site in the context of sedimentology, bathymetry, and hydrogeochemistry. The assessment showed an increase in the amount of silt and clay, and the seabed was noticeably elevated. The nutrient concentration, the pH value, and the salinity index demonstrate that the site is conducive in establishing mangrove seedlings. As a result, we conclude that the site is now ready for attempts to rehabilitate the lost mangrove forest.

Isolation and characterization of microsatellite loci in an endangered palm, Johannesteijsmannia lanceolata (Arecaceae)

PREMISE OF THE STUDYnMicrosatellite markers were developed for Johannesteijsmannia lanceolata to assess the genetic diversity and mating system of this alarmingly endangered species.nnnMETHODS AND RESULTSnA total of 31 polymorphic microsatellite markers were developed for J. lanceolata using the enrichment protocol. These markers were screened on 24 samples from a natural population. The number of alleles ranged from four to 20, while the observed heterozygosity ranged from 0.391 to 1.000. The 31 loci were further tested for transferability on J. altifrons, J. magnifica, and J. perakensis. Generally, all loci showed positive amplifications in these three Johannesteijsmannia species, except Jla124 (J. magnifica) and Jla168b (J. magnifica and J. perakensis).nnnCONCLUSIONSnThese microsatellite markers could be employed to study the population genetics and mating system of J. lanceolata and other Johannesteijsmannia species.