香港米埔自然保护区保护与管理经验及启示

随着深圳市城市发展步伐的不断加快,福田红树林自然保护区受到水体污染、人为干扰、病虫害及外来物种等各方面影响,导致其生态系统出现不同程度的退化。通过赴香港米埔自然保护区考察与学习,分析了香港米埔自然保护区精细化管理、生态系统日趋稳定及教育宣传等经验,提出了深圳福田乃至全国红树林自然保护区保护与管理对策和建议。     

Nature and geochemistry of surface sediments of the mangrove environment along the Egyptian Red Sea coast

Grain size and geochemical analyses have been carried out on 58 samples collected from different areas of mangrove environment of the Egyptian Red Sea coast. The texture characteristics of mangrove sediments show that the mean size decreases in sediments of coastal areas while increase in island sediments and the sediment type generally changes from sand to slightly gravelly muddy sand. The sediments are composed mainly of poorly sorted, negatively nearly symmetrical and leptokurtic fine sands. Cluster analysis showed that, distribution of gravel, sand and mud fractions is related to bottom facies and type of sediment source. Generally, sand fraction is the main category among the three constituents. Geochemically the factor controlling the carbonate content of studied sediments includes material supply of biogenic and terrigenous components. Therefore, sediments of Hamata area, km 17 south Safaga, Wadi El-Gemal Island and Abu-Minqar Island are terrigenous sediments, while sediments of km 37 north Quseir are highly carbonates. In general organic matter is higher in the mangrove sediments relative to adjacent areas. The high organic matter in the mangrove sediments is primarily due to the high supply from primary productivity, terrestrial and reworked sediments. Texture is the main controlling factor for the organic matter enrichment. Spatial variations in the phosphorus content in the different studied localities are related to the sources of phosphorus to the area. In comparison, cluster analysis indicates that phosphorus might be transported from terrestrial source to the sea through wadis draining the excavated Upper Cretaceous phosphate rocks. Also, the abundance of phosphorus content may be attributed to phosphatization of calcareous skeletons. Our observations provide knowledge on the physico-chemical effects and will be useful in the management and suitable development of the areas under study. In addition it represent database in the future.     

The state of legislation and policy protecting Australia's mangrove and salt marsh and their ecosystem services

Saline coastal wetlands, such as mangrove and coastal salt marsh, provide many ecosystem services. In Australia, large areas have been lost since European colonization, particularly as a result of drainage, infilling and flood-mitigation works, often starting in the mid-19th century and aimed primarily towards converting land to agricultural, urban or industrial uses. These threats remain ongoing, and will be exacerbated by rapid population growth and climate change in the 21st century. Establishing the effect of wetland loss on the delivery of ecosystem services is confounded by the absence of a nationally consistent approach to mapping wetlands and defining the boundaries of different types of coastal wetland. In addition, climate change and its projected effect on mangrove and salt marsh distribution and ecosystem services is poorly, if at all, acknowledged in existing legislation and policy. Intensifying climate change means that there is little time to be complacent; indeed, there is an urgent need for proper valuation of ecosystem services and explicit recognition of ecosystem services within policy and legislation. Seven actions are identified that could improve protection of coastal wetlands and the ecosystem services they provide, including benchmarking and improving coastal wetland extent and health, reducing complexity and inconsistency in governance arrangements, and facilitating wetland adaptation and ecosystem service delivery using a range of relevant mechanisms. Actions that build upon the momentum to mitigate climate change by sequestering carbon – ‘blue carbon’ – could achieve multiple desirable objectives, including climate-change mitigation and adaptation, floodplain rehabilitation and habitat protection.     

雷州半岛红树林海区的鱼类种类调查

对雷州半岛8个红树林分布区设站位进行了生物多样性调查,其中获得鱼类127种,分别隶属于15目58科100属。以鲈形目最多,共27科49属65种,占51.2％。种类出现最多的科为(鱼叚)虎鱼科。采获种类最多的站位为北潭。各站位之间鱼类种类具有一定的差异性。调查获得的鱼类体型偏小,大部分种类具有食用价值,其中16种已为人工增养殖的对象。     

Deforestation in the Ayeyarwady Delta and the conservation implications of an internationally-engaged Myanmar

Myanmar is a country of huge biodiversity importance that is undergoing major political change, bringing with it new international engagement. This includes access to international markets, which will likely spur investment in export-oriented agriculture, leading to increased pressures on already threatened ecosystems. This scenario is illustrated in the Ayeyarwady Delta, the country's agricultural heartland sustaining high deforestation rates. Using the Delta as a model system, we use an integrated approach to inquire about whether and how imminent agricultural reforms associated with an internationally-engaged Myanmar could introduce new actors and incentives to invest in agricultural expansion that could affect deforestation rates. We use a novel remote sensing analysis to quantify deforestation rates for the Delta from 1978 to 2011, develop business-as-usual deforestation scenarios, and contextualize those results with an analysis of contemporary policy changes within Myanmar that are expected to alter the principal drivers of land-cover change. We show that mangrove systems of Myanmar are under greater threat than previously recognized, and that agriculture has been the principle driver of deforestation on the Delta. The centrality of agriculture to the Myanmar economy indicates that emerging policies are likely to tip the scales towards agricultural expansion, agro-industrial investment and potentially greater rates of deforestation due to the introduction of well-funded investors, insufficient land tenure agreements, and low governance effectiveness. The broad national challenge is to initiate environmental governance reforms (including safeguards) in the face of significant pressures for land grabbing and opportunistic resource extraction.     

Monitoring Mangrove forest landcover changes in the coastline of Bangladesh from 1976 to 2015

Abstract

This study used multi-date Landsat images to quantify mangrove cover changes in the whole of Bangladesh from 1976 to 2015. Images were pre-processed with an atmospheric correction using Dark Object Subtraction (DOS) and Relative Radiometric Normalization (RRN) using Pseudo-Invariant Features (PIFs). Land Use/Land Cover (LU/LC) classification map was generated using Maximum Likelihood (MaxLike) algorithm, indicating the areal extent of mangroves increased by 3.1% between 1976 and 2015, where 1.79% of this increase occurred between 2000 and 2015. Though mangrove areas remained almost constant in the Sundarbans, Chakaria Sundarbans has almost disappeared between 1976 and 1989. The overall accuracy of Landsat MSS, TM, ETM+, and L8 OLI classified images were 80%, 80%, 87%, and 97% respectively. The study also found deforestation, shrimp & salt farm, coastal erosion and sedimentation, and mangrove plantation could be responsible for mangrove changes in Bangladesh.     

Abilities and genes for PAH biodegradation of bacteria isolated from mangrove sediments from the central of Thailand

PAH-degrading bacteria, including Novosphingobium sp. PCY, Microbacterium sp. BPW, Ralstonia sp. BPH, Alcaligenes sp. SSK1B, and Achromobacter sp. SSK4, were isolated from mangrove sediments. These isolates degraded 50–76% of 100 mg/l phenanthrene within 2 weeks. Strains PCY and BPW also degraded pyrene at 98% and 71%, respectively. Furthermore, all of them probably produced biosurfactants in the presence of hydrocarbons. Interestingly, PCY has a versatility to degrade various PAHs. Molecular techniques and plasmid curing remarkably revealed the presence of the alpha subunit of pyrene dioxygenase gene (nidA), involving in its pyrene/phenanthrene degrading ability, located on megaplasmid of PCY which has never before been reported in sphingomonads. Moreover, genes encoding ferredoxin, reductase, extradiol dioxygenase (bphA3A4C) and exopolysaccharide biosynthetase, which may be involved in PAH degradation and biosurfactant production, were also found in PCY. Therefore, we conclude that these isolates, especially PCY, can be the candidates for use as inoculums in the bioremediation.     

湛江红树林保护区水鸟监测及水鸟资源现状

介绍了湛江红树林保护区近年来持续进行的鸟类监测调查相关方法及目前区内水鸟资源现状。经过数年调查,保护区已积累了大量丰富的数据,区内水鸟种类和数量已基本摸清,对鸟类保护中存在的问题进行了分析并提出了相关建议。     

Influence of mangrove reforestation on heavy metal accumulation and speciation in intertidal sediments

To investigate the influence of mangrove reforestation on heavy metal accumulation and speciation in intertidal sediments, core sediments from a restored mangrove forest and adjacent mud flat in Yifeng Estuary (southeastern China) were analyzed. The chemical speciation of heavy metals (Pb, Zn, Cu, Cr and Ni) was determined according to a sequential extraction procedure. Special attention was paid to the upper 20 cm of sediment, in which metal accumulation was enhanced and speciation was obviously modified. Mangrove reforestation decreased the concentrations of all metals in the acid-soluble fraction and increased metal concentrations in the oxidizable fraction. Increased Pb, Zn and Cu concentrations and decreased Ni and Cr concentrations were observed in the reducible fraction. These results suggest that mangrove reforestation facilitated the accumulation of heavy metals in the upper sediment layers but decreased their bioavailability and mobility.     

Evaluation of solid residues removed from a mangrove swamp in the São Vicente Estuary, SP, Brazil

Mangrove swamps are found in estuaries along the coastal plains of tropical regions and have be subjected to heavy occupation and use pressure due to their privileged locations and abundance of biological resources. The present work evaluated the ecological characteristics and solid wastes accumulated in eight areas along the Santos - São Vicente Estuary Complex. The superficially deposited residues at each sampling site were collected and subsequently washed, drained, counted, weighed and separated into classes according to their composition and predominant use. The predominant litter type in terms of density was plastic (62.81%) and, by weight, wood (55.53%). The greatest deposition of residues was associated with areas that were less inclined and that had low plant density levels, indicating that the presence of obstacles was not critical for retaining floating residues in mangrove areas. The presence of the most frequently encountered types of solid waste residues could be explained by local activities.