Biomass and carbon stocks in mangrove ecosystems of Kerala,southwest coast of India

Background:Mangroves are important tropical carbon sinks,and their role in mitigating climate change is well documented across the globe.However,the ecosystem carbon stocks in the mangroves of India have not been studied comprehensively.Data from this region is very limited for providing sufficient insights and authentic evaluation of carbon stocks on a regional scale.In this study,we evaluated the ecosystem carbon stock and its spatial variation in mangroves of Kerala,southwest coast of India.Results:The mean biomass stored in mangrove vegetation of Kerala is 117.11±1.02 t/ha(ABG=80.22±0.80,BGB=36.89±0.23 t/ha).Six mangrove species were found distributed in the study area.Among the different species,Avicennia marina had the highest biomass(162.18 t/ha)and least biomass was observed in Sonneratia alba(0.61 t/ha).The mean ecosystem carbon stock of mangrove systems in Kerala was estimated to be 139.82 t/ha,equivalent to 513.13 t CO2 e/ha with the vegetation and soil storing 58.56 t C/ha and 81.26 t C/ha respectively.Conclusion:The present study reveals that Kerala mangroves store sizable volume of carbon and therefore need to be preserved and managed sustainably,to retain along with the increase in carbon storage.This features the need of broadening mangrove cover as well as restoring deteriorated land in the past 50 years.Although mangrove forests in this region are protected by the Kerala Forest Department,they have been frequently facing illegal encroachment,prawn cultivation,and coastal erosion.

Impact of coastal development on mangrove cover in Kilim river, Langkawi Island, Malaysia

We examined the impact of various coastal developments on mangrove cover along the Kilim River, Langkawi Island, Malaysia between 1996 and 2008. We analysed images from Systeme Probatoire d＇Observation de la Tarre （SPOT） of Kilim River using supervised classification and Principal Component Analysis （PCA）. Over 8% （176.83 ha] of mangrove cover was degraded along the Kilim River from its total area of 2153.07 ha during the past 14 years. We identified several causes of mangrove degradation, including mangrove clearing （38%）, mangrove conversion to commercial area （21%）, residential area （19%）, agriculture （12%）, aquaculture （12%） and wake current （6%）. Langkawi is one of the main tourism islands in Malaysia. Tthe pace of coastal development throughout the entire island including Kilim River had suppressed the mangroves propagation over the years. Long term monitoring of mangrove ecosystems is essentials to ensure the survival and sustainability of mangrove associated biodiversity.

Mangrove Ecosystem Services: Indus Delta (PQA), Sindh

Mangroves of the Indus Delta are the world’s fifth largest assemblage, and the largest in the arid zone. Mangroves of Indus delta (PQA) provide immense benefits, products and unrecognized regulatory services. Products of Direct Economic Value: Fish, Minerals and food. There are Products of Natural System (intangible) supplies of rich nutrients to support productivity. Coastal communities benefit in a multitude of ways from Mangrove ecosystems. Collectively, these benefits are known as ecosystem services. The ecological role of mangrove ecosystems in the Indus Deltaic area of Port Qasim Authority (PQA) is, economically and socially significant. The Mangroves are well known for their high biological productivity and their consequent importance provided to the coastal community in terms of services and products of direct and indirect value to the adjacent coastal waters. Mangrove Ecosystem services are regularly involved in the provisioning of food and services and the decomposition of organic wastes. They export organic matter, mainly in detritus form of leaf litter to the marine environment, thus providing a highly nutritious food source for themselves and for the Benthic and terrestrial animals found in the mangrove areas, as well as for those in neighboring estuarine and marine ecosystems. Apart from nutrient export, mangroves also contribute to offshore fisheries by acting as nurseries and shelters for many species of commercially important finfish and crustaceans. Degradation of Indus Deltaic mangrove in PQA would destabilize the economic potential and the livelihood of communities’ which include services and benefits offered by the mangrove ecosystem. Rehabilitation and conservation of mangroves ecosystem in PQA is essential for sustained biological productivity in the region.

Impact of trimming intensity on the growth of mangrove in Iran

Mangrove forests in southern Iran are of high ecological and economic importance.These forests are being threatened because of uncontrolled harvesting to provide fodder for livestock.The objective of this study is to provide recommendations for appropriate harvesting intensities by quantifying the effect of different harvesting intensities on vegetative and vigor characteristics of mangrove trees.This study was conducted using a randomized complete block design comprising four treatments(10.00%,20.00%,and 30.00% trimming,along with a control)replicated three times.Vegetative characteristics were measured before and after trimming(five-year period)and analyzed using generalized linear model statistical analysis.The growths of the average diameter of canopy,canopy area,canopy volume,canopy height,tree height,and collar diameter in the control treatment were all significantly higher than those in the trimming treatments.In addition,there was a decreasing trend in leaf fresh and dry mass,leaf area index,total area of canopy leaves,and health status of tree in the trimming treatments.For example,the percentage change in fresh and dry leaf mass in the control treatment was positive(29.87% and 38.31%,respectively),whereas the trimming treatments of 10.00%,20.00% and 30.00% had negative effects(-7.01% and -4.79%,-11.32% and -14.30%,and -15.84% and -17.29%,respectively).In addition,the changes in leaf area index in the control(4.95%)and 30.00% trimming(-24.57%)treatments were the highest and lowest,respectively.The percentage change in soil organic matter in the control,10.00%,20.00%,and 30.00% treatments were 22.94%,-9.90%,-16.91%,and -18.68%,respectively.The study demonstrated that gray mangrove trees were highly sensitive to canopy trimming,with even minimal trimming intensities negatively affecting vegetative growth and soil organic matter.Therefore,it is recommended that cutting and trimming of mangrove trees should be prevented even at low intensity to preserve mangrove ecosystem health and resilience against environmental stressors.

Application of Principal Component Analysis(PCA)to the Evaluation and Screening of Multiactivity Fungi

Continued innovation in screening methodologies remains important for the discovery of high-quality multiactive fungi,which have been of great significance to the development of new drugs.Mangrove-derived fungi,which are well recognized as prolific sources of natural products,are worth sustained attention and further study.In this study,118 fungi,which mainly included Aspergillus spp.(34.62%)and Penicillium spp.(15.38%),were isolated from the mangrove ecosystem of the Maowei Sea,and 83.1%of the cultured fungi showed at least one bioactivity in four antibacterial and three antioxidant assays.To accurately evaluate the fungal bioactivities,the fungi with multiple bioactivities were successfully evaluated and screened by principal component analysis(PCA),and this analysis provided a dataset for comparing and selecting multibioactive fungi.Among the 118 mangrove-derived fungi tested in this study,Aspergillus spp.showed the best comprehensive activity.Fungi such as A.clavatonanicus,A.flavipes and A.citrinoterreus,which exhibited high comprehensive bioactivity as determined by the PCA,have great potential in the exploitation of natural products and the development of new drugs.This study demonstrated the first use of PCA as a time-saving,scientific method with a strong ability to evaluate and screen multiactive fungi,which indicated that this method can affect the discovery and development of new drugs.

Accumulation of polycyclic aromatic hydrocarbons from contaminated soil by Kandelia candel

The purpose of this study was to investigate the accumulation behavior of two typical PAHs, phenanthrene （PHE） and fluoranthene （FLA）, uptaken by the mangrove Kandelia candel in various treated sandy soils. The experiment lasted for three months. Soil and plant samples were collected after 3, 6, 9 and 13 weeks of the incubation and the levels of PAHs were analyzed using a GC/MS （HP6890-5975B）. The results showed that the root accumulations of PHE and FLA were elevated with the increase of the PAH concentrations in the soil. With prolonged exposure time, PHE and FLA concentrations of the roots increased significantly in comparison with the control. PHE and FLA concentrations of root after 13 weeks of treatment ranged from 0.28 to 4.36 #g.g-1 and 0.79 to 35.76 pg.g 1 respectively. The calculated mean values of the root concentration factors were 0.58 for PHE and 0.71 for FLA. This indicated that root accumulation of FLA was greater than PHE, which would result from the higher octanol-water partition coefficient （Kow） of FLA. These results underline the ability of mangroves to remove PAHs from contaminated marine substrates and hence their potential use in bioremediation and the removal of PAHs from the marine food chain.