莫莫格湿地生态演变及水源解决途径探析

湿地的生态演变是区域性生态演变的前奏，而水是生态环境的控制性因素。     

钦州港红树林鱼类群落时间变化格局及其与潮差等环境因子关系

于2011-10-2012-09研究了广西钦州港红树林水域鱼类的物种组成、群落变化及与环境因子的关系.发现该水域鱼类共计55种,隶属于10目27科47属,虾虎鱼科物种最多.该水域鱼类优势种明显,其中青斑细棘虾虎鱼和中华乌塘鳢分别为鱼类群落的第一和第二优势种.物种数、个体数和生物量从1 ～12月的月份变化可分为上升一稳定波动一下降3个阶段.夏、秋季鱼类物种及个体较多,冬季与其他季节间物种数、个体数和生物量存在显著差异.冬季物种多样性指数和均匀度指数较高,夏、秋季物种丰富度指数和优势度指数较高.无度量多维排序结果显示鱼类群落分离明显,表明季节、月份间群落结构变化明显.典范对应分析结果显示鱼类群落与水温、盐度、pH、潮差显著相关,且相关性大小依次降低.此外,研究还表明：鱼类物种数和个体数与潮差和水温呈显著正相关,与盐度和pH呈显著负相关.     

基于神经网络和数据融合的红树林群落分类研究

及时准确地掌握红树林群落现状信息可为保护和修复红树林生态系统提供重要的决策依据。对红树林群落进行遥感分类在实际应用中具有较大的意义。但红树林各群落间的光谱差异很微弱,有必要采用多源遥感数据融合的方法来提高分类的精度。本文以珠海淇澳岛红树林区为例,使用SAR图像与TM图像,探讨了监督分类、非监督分类以及神经网络分类3种分类方法和IHS融合、小波融合以及主成分融合3种融合方法对红树林群落进行分类的效果。结果表明,对SAR与TM主成分融合图像应用神经网络分类方法能够取得最好的分类效果。     

Effects of land use and changes in cover on the transformation and transportation of iron:A case study of the Sanjiang Plain,Northeast China

Wetland reclamation has been ongoing in the Sanjiang Plain since the mid-1950s,which has resulted in major changes in wetlands and the agriculture ecosystem in the region that have influenced the iron output to the Sea of Okhotsk and limited the primary productivity in the North Pacific Ocean.This study was conducted to investigate the chemical forms of iron in different aquatic environments(agricultural water including groundwater,paddy water,and canal water;wetland water including marsh water,marsh stream...     

红树林放线菌的筛选与抗真菌和抗肿瘤活性的测定

通过从深圳福田红树林根际于不同季节采集的3份土样和2份水样中分离得到95株放线菌,94%的放线菌为链霉菌属。测定95株放线菌发酵液对9种病原真菌的抗菌活性,其中31.6%的放线菌发酵液有不同程度的抗病原真菌作用。同时采用MTT法测定了它们对肺癌细胞A549、白血病细胞株K562两种肿瘤细胞的细胞毒活性,其中21%放线菌发酵液具有细胞毒活性。s33、s62、s65和s68这个4株放线菌发酵液具有抑制5种以上真菌的作用,并且对两种肿瘤细胞株均有作用。     

红树林土壤纤维素酶产生菌筛选及产酶条件研究

采用CMC唯一碳源平板法和内切葡聚糖酶、外切葡聚糖酶和β-葡萄糖苷酶等3种酶平板鉴别法从海南红树林土壤中分离到109个有阳性信号的菌株,经发酵产酶复筛选出一株产纤维素酶活相对较高的真菌HBZ003。经鉴定该菌为产紫青霉(Penicillium purpurogenum)。通过发酵产酶条件优化,获得最佳培养基组成为:麸皮8 g/L,CMC 2 g/L,(NH4)2SO43 g/L,KNO32 g/L,KH2PO43 g/L,NaCl 6 g/L,CaCl20.5 g/L;发酵条件为250mL三角瓶中装培养液100mL,在pH4.0、30℃,160 r/min条件下振荡培养5 d,测得发酵液中CMCase和FPA分别为16.04U和4.08 U。     

Characterizing patterns of plant distribution in a southern California salt marsh using remotely sensed topographic and hyperspectral data and local tidal fluctuations

We used LiDAR topographic data, AVIRIS hyperspectral data, and locally measured tidal fluctuations to characterize patterns of plant distribution within a southern California salt marsh (Carpinteria Salt Marsh (CSM)). LiDAR data required ground truthing and correction before they were suitable for use. Twenty to forty percent of the uncertainty associated with LiDAR was due to variance in the elevation of the target surface, the balance was attributed to error inherent in the LiDAR system. The incidence of LiDAR penetration of plant canopy cover (i.e., registration of ground elevation) was only three percent. The depth of LiDAR penetration into the plant canopy varied according to plant species composition; plant species-specific corrections significantly improved LiDAR accuracy (58% reduction in overall uncertainty) and with the use of ground-based surveys, reduced overall RMSE to an average of 6.3 cm in vegetated areas. A supervised classification of AVIRIS data was used to generate a vegetation map with six classification types; overall classification accuracy averaged 59% with a kappa coefficient of 0.40. The vegetation classification map was overlaid with a LiDAR-based digital elevation model (DEM) to compute elevation distributions and frequencies of tidal inundation. The average elevations of the dominant plant classifications found in CSM (e.g., Salicornia virginica, Jaumea carnosa, and salt-grass mix, a mixture of multiple marsh plant species) occurred within a 17 cm range, a vertical change that resulted in a 7% difference in the period of tidal inundation.     

Associations between Breeding Marsh Bird Abundances and Great Lakes Hydrology

We used Great Lakes hydrologic data and bird monitoring data from the Great Lakes Marsh Monitoring Program from 1995–2002 to: 1) evaluate trends and patterns of annual change in May-July water levels for Lakes Ontario, Erie, and Huron-Michigan, 2) report on trends of relative abundance for birds breeding in Great Lakes coastal marshes, and 3) correlate basin-wide and lake-specific annual indices of bird abundance with Great Lakes water levels. From 1995–2002, average May, June, and July water levels in all lake basins showed some annual variation, but Lakes Erie and Huron-Michigan had identical annual fluctuation patterns and general water level declines. No trend was observed in Lake Ontario water levels over this period. Abundance for five of seven marsh birds in Lake Ontario wetlands showed no temporal trends, whereas abundance of black tern (Chlidonias niger) declined and that of swamp sparrow (Melospiza georgiana) increased from 1995–2002. In contrast, abundances of American coot (Fulica americana), black tern, common moorhen (Gallinula chloropus), least bittern (Ixobrychus exilis), marsh wren (Cistorthorus palustris), pied-billed grebe (Podilymbus podiceps), sora (Porzana carolina), swamp sparrow, and Virginia rail (Rallus limicola) declined within marshes at Lakes Erie and Huron/Michigan from 1995–2002. Annual abundances of several birds we examined showed positive correlations with annual lake level changes in non-regulated Lakes Erie and Huron/Michigan, whereas most birds we examined in Lake Ontario coastal wetlands were not correlated with suppressed water level changes of this lake. Overall, our results suggest that long-term changes and annual water level fluctuations are important abiotic factors affecting abundance of some marsh-dependent birds in Great Lakes coastal marshes. For this reason, wetland bird population monitoring initiatives should consider using methods in sampling protocols, or during data analyses, to account for temporal and spatial components of hydrologic variability that affect wetlands and their avifauna.     

Four general principles for the management and conservation of wetlands in large lakes: The role of water levels,nutrients, competitive hierarchies and centrifugal organization

The most important factor in shoreline wetlands is variation in water depth. Superimposed upon this are gradients of soil fertility, ranging from sandy, open shorelines to sheltered, fertile bays. The use of both transplant and pot experiments shows that competitive hierarchies rapidly arise in wetland vegetation and that species are sorted along exposure and depth gradients according to their relative competitive abilities. These patterns can be summarized in the centrifugal organization model, in which competitive dominants occupy preferred core habitats and where different species and vegetation types are then arrayed outward along different constraint gradients ( Wisheu & Keddy 1992 ). Knowledge of these general patterns provides an essential tool for managing lakes and reservoirs in order to maintain and enhance biological diversity.     

人工曝气与生态湿地相结合改善清河口水环境

针对清河入河口现状水污染的特点,利用现状低洼坑塘,采用人工曝气和生态湿地相结合的组合工艺,对河道水体进行处理,可有效地去除水中的有机物污染和黑臭,减少水体中营养物质含量,改善水色及透明度,使清河口水环境得到明显改善.