共查询到19条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
根据国际《湿地公约》中的湿地定义,分析了长江中下游湿地面临的主要生态问题,提出了加强长江中下游湿地生态保护、促进经济与社会可持续发展的对策和建议。 相似文献
5.
从建湖县“九龙口”省级风景名胜区湿地的实际出发,分析了湿地生态保护的必要性,根据保护原则,提出了相应的保护措施。 相似文献
6.
基于“压力—状态—响应”模型和分形理论的湿地生态健康评价 总被引:5,自引:0,他引:5
科学评价湿地生态系统健康是湿地管理和保护的重要前提。以海河流域河北衡水湖湿地为例,采用"压力—状态—响应"(PSR)模型对其健康评价进行探讨研究,并对该模型的压力、状态和响应部分分别建立相应的指标体系;该指标体系不仅将生态、经济、社会要素结合起来,而且考虑了湿地所处地区的社会经济结构、湿地所具有的功能以及管理部门、个人及企业等对保护湿地所采取的措施。同时,根据湿地生态系统具有自组织、自相似的特征,基于分形理论对其进行评价。计算分析时首先对选择的各指标进行归一化处理,然后采用最小二乘法求解拟合曲线斜率的方法来计算分维数(D),由1/D得到脆弱度,以此作为评价健康程度的依据。计算结果表明,D=0.5826,则脆弱度为1.7164,表明衡水湖湿地生态系统处于不健康程度。该湿地亟待开展进一步的科学管理和生态保护。 相似文献
7.
浙江省生物多样性保护对策研究 总被引:5,自引:0,他引:5
由于森林的破坏与片段化、湖泊面积缩小、水域污染、滩涂湿地围垦和物种资源过度开发利用等原因,使生物多样性严重受协。在对浙江省生物多样性保护进行系统研究的基础上,提出了浙江省生物多样性保护的目标和主要对策。 相似文献
8.
9.
10.
11.
12.
Custer TW Custer CM Johnson KM Hoffman DJ 《Environmental pollution (Barking, Essex : 1987)》2008,155(2):217-226
Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch. 相似文献
13.
The purpose of this research was to determine the abundance of the nitrogen-fixing shrub, Alnus incana ssp. rugosa (speckled alder), in shrub wetlands of the Adirondack Mountain region of New York State and to determine whether its abundance affects the concentration or accumulation of inorganic nitrogen in wetland substrates. Alder/willow wetlands are the second most common wetland type in the Adirondack region. The Adirondack Park Agency's digital GIS database of wetland types was used to determine the areal extent of alder/willow wetlands in the Adirondacks. Randomly selected wetlands were sampled to determine the size and abundance of alder. Alder densities averaged approximately 7000 stems ha(-1) and alder was present in 75% of the wetlands. As an indication of short-term accumulation of NO(3-) and NH4(+) in wetland substrates, ion exchange resins were used to sample ground water in high and low alder density wetlands as well as from wetlands lacking alder and dominated by conifers. Additionally, NO(3-) and NH(4+) concentrations in ground water samples were measured. NH(4+) accumulation levels from exchange resins were low for all wetland types while groundwater NH(4+) concentration was highest in the low-density alder sites. Wetlands with high alder density had approximately six times higher NO(3-) accumulation than other wetlands. Substrate groundwater NO(3-) concentrations in wetlands of high-density alder exceeded by three times levels in low or no alder wetlands, showing the importance of alder to local N budgets. To assess the recovery of shrub wetlands from acidification, future studies should determine the fate of fixed N in wetland systems. 相似文献
14.
In southern Sweden, wetlands are constructed to remove nitrogen (N) in agricultural catchments. The possible effects of such wetlands on riverine phosphorus (P) were also estimated using input-output data from three well-monitored wetlands. This was done to formulate a simple model for removal of P that is dependent on inflow characteristics. Next, the N- and P-reducing effects of wetlands were modeled on a catchment scale (1900 km2) using the HBV-NP model and various assumptions about the wetland area and location. All three wetlands functioned as sinks for total P (tot-P) and for total suspended solids (TSS) with a removal of 10% to 31% and 28% to 50%, respectively. Mean P-removal rates of 17-49 kg ha(-1) yr(-1) were well simulated with the model. Catchment scale simulations indicated that wetlands were more efficient (in percentage of load) as traps for P than for N and that this may motivate the construction of wetlands for P removal far upstream from the catchment outlet. 相似文献
15.
Assessment of heavy metal pollution in wetland soils from the young and old reclaimed regions in the Pearl River Estuary, South China 总被引:16,自引:0,他引:16
Bai J Xiao R Cui B Zhang K Wang Q Liu X Gao H Huang L 《Environmental pollution (Barking, Essex : 1987)》2011,159(3):817-824
Soils were sampled in three types of wetlands from the young (A) and old (B) reclaimed regions of the Pearl River Estuary. They were analyzed for total concentrations of heavy metals to investigate their distributions and pollution levels in both regions. Results showed that most heavy metals in ditch and riparian wetlands did not significantly differ from those in reclaimed wetlands in A region, while significantly lower for Cd, Cu, Pb, and Zn in reclaimed wetlands in B region, suggesting higher effects of long-term reclamation. Iron, Cr and Cu were identified as metal pollutants of primary concern and had higher contributions to the total toxic units compared to other metals. Almost all metals exceeded their lowest effect levels and Fe and Cr even exceeded the severe effect levels. Multivariate analysis shows that Fe and Mn are controlled by parent rocks and other metals mainly originate from anthropogenic source. 相似文献
16.
An S Li H Guan B Zhou C Wang Z Deng Z Zhi Y Liu Y Xu C Fang S Jiang J Li H 《Ambio》2007,36(4):335-342
Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% costal wetlands) because of the wetland reclamation during China's long history of civilization, and the population pressure and the misguided policies over the last 50 years. Recently, with an improved understanding that healthy wetland ecosystems play a vital role in her sustainable economic development, China started major efforts in wetland conservation, as signified by the policy to return reclaimed croplands to wetlands, the funding of billions of dollars to restore degraded wetlands, and the national plan to place 90% of natural wetlands under protection by 2030. This paper describes the current status of the natural wetlands in China, reviews past problems, and discusses current efforts and future challenges in protecting China's natural wetlands. 相似文献
17.
2种人工湿地的水力停留时间及净化效果 总被引:2,自引:0,他引:2
以复合垂直流人工湿地(IVCW)和水平潜流人工湿地(HSCW)为研究对象,研究了2种湿地运行的季节性最佳水力停留时间(HRT)参数,并监测了2种湿地在最佳HRT参数下运行时对污水的净化效果。结果显示:(1)在IVCW中,最佳HRT在春、秋季为8~10 h;夏季为6 h;冬季为12 h。在HSCW中,最佳HRT在春、秋季为10~12 h;夏季为6~8h;冬季为24~36 h。(2)2种湿地对COD的去除率均无显著的季节性差异;湿地进水中NH4+-N/TN比值与TN去除率显著负相关;不同季节下IVCW对TN的去除效果均高于HSCW。(3)水温对TN、TP去除率的影响在IVCW中比HSCW中的明显;水温高时,2种湿地中的TN去除率较高,IVCW中的TP去除率也较高,但HSCW中的TP去除率则较低,它们间均未达到显著的相关性。 相似文献
18.
构建小试试验研究了正反粒径混合级配填铺与正粒径级配填铺(组合填料为钢渣与灰岩)的垂直潜流人工湿地单元对生活污水中各主要指标的降解效果,同时比较分析了填料填铺方式对缓解人工湿地堵塞问题的影响.结果表明,当原水COD在134.72~653.33 mg/L、NH3-N在42.72~272.60mg/L,TN在107.40~6... 相似文献
19.
The wet landscape approach to oil sands tailings reclamation in the Athabasca Oil Sands region involves creating wetlands from fluid tailings in mined-out pits. We measured time to metamorphosis, thyroid hormone status, and detoxification enzyme (EROD) induction in Wood frog (Lithobates sylvaticus) tadpoles raised on reclaimed oil sands wetlands of different ages [young (≤7 yr) vs. old (>7 yr)] and compared data with tadpoles raised on reference (control) wetlands. Metamorphosis was delayed or never occurred in tadpoles raised in young tailings; those exposed to older tailings developed similarly to those in reference wetlands. Thyroid hormone disruption likely played an important role in the metamorphosis delay as the T3:T4 ratio was lowest in tadpoles raised in young, tailings-affected wetlands. Our findings suggest tailings wetlands become less toxic with age, and that these amphibians will be able to complete their life cycle in tailing wetlands that have sufficiently detoxified with age. 相似文献