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1.
中国海岸带围垦遥感分析   总被引:10,自引:5,他引:5  
吴文挺  田波  周云轩  舒敏彦  戚纤云  胥为 《生态学报》2016,36(16):5007-5016
海岸带围垦是沿海区域缓解人口增长与城镇扩张所带来土地压力的重要途径和方式。建国以来,中国大陆沿海围垦大量滨海湿地以满足社会经济发展所导致的土地需求,对滨海湿地的资源、生态和环境造成影响和胁迫。为掌握近35年来中国大陆沿海地区的围填海状况,以5a为间隔,选取1985—2010年间Landsat系列卫星影像数据,基于遥感与GIS技术,解译6个年份的围垦岸线,计算分析围垦面积,研究并提出围垦强度系数。结果表明,1985—2010年,中国大陆沿海共围垦土地755183 hm~2,年均围垦30207 hm~2,围垦强度达到1.7 hm~2a~(-1)km~(-1),围垦总量趋势表现先减少后增加。环渤海经济圈与长三角经济圈围垦强度最大,其围垦总量占到全国总体的85.7%。围垦的时空分布及其利用形式受沿海区域自然地理条件和地区经济发展水平的制约和影响。  相似文献   

2.
This study provides an integrated approach using geographical information system (GIS) based on a multi-criteria approach (MCDA) to assess coastal vulnerability, resulting from human activity, population density, erosion, and climate change-induced sea level rise. A coastal vulnerability index (CVI) for erosion and floods was calculated and mapped (~24 km in length; ~400 m in width, and 11.47 km2 in surface) for the lagoon barrier of Nador located on the Mediterranean coast of Morocco. Results suggest that 54% (~13 km) of the shoreline is moderately vulnerable, while 42% (~10 km) is highly vulnerable and only 4% (1 km) present a low vulnerability. The vulnerability map of the socio-economic activities indicates that most wetlands and forest areas 83% (~31 ha) and 50% (~440 ha) respectively, present low vulnerability. 52% percent of artificial areas (~23 ha), 73% of agricultural land (~128 ha), and 41% of natural areas (~363 ha) present moderate vulnerability. However, the level of vulnerability of the remaining artificial and agricultural areas classifies from high to very high. The north-western sector was classified as the most vulnerable area, characterized by an erosion (?0.6 m/yr to ?1.20 m/yr) for 70% of this area, while the south-eastern part shows a low to moderate vulnerability marked by an erosion (?0.1 m/yr to ?1m/yr) for 40% of this area. Coastal vulnerability maps have potential as decision tools to prepare and respond to sea level rise, and identify exposed coastal zones, as such contributing to national climate action and disaster risk reduction sustainable development goals (goals 13 and 11, respectively).  相似文献   

3.
Coastal upwelling regions, which are affected by equatorward‐wind variability, are among the most productive areas of the oceans. It has been suggested that global warming will lead to a general strengthening of coastal upwelling, with important ecological implications and an impact on fisheries. However, in the case of the Iberian upwelling, the long‐term analysis of climatological variables described here reveals a weakening in coastal upwelling. This is linked to a decrease of zonal sea level pressure gradient, and correlated with an observed increase of sea surface temperature and North Atlantic Oscillation. Weakening of coastal upwelling has led to quantifiable modifications of the ecosystem. In outer shelf waters a drop in new production over the last 40 years is likely related to the reduction of sardine landings at local harbors. On the other hand, in inner shelf and Ria waters, the observed weakening of upwelling has slowed down the residual circulation that introduces nutrients to the euphotic layer, and has increased the stability of the water column. The drop in nutrient levels has been compensated by an increase of organic matter remineralization. The phytoplankton community has responded to those environmental trends with an increase in the percentage of dinoflagellates and Pseudonitzschia spp. and a reduction in total diatoms. The former favors the proliferation of harmful algal blooms and reduces the permitted harvesting period for the mussel aquaculture industry. The demise of the sardine fishery and the potential threat to the mussel culture could have serious socio‐economic consequences for the region.  相似文献   

4.
Mexico has two main types of coasts, an Amero-trailing-edge coast along the Gulf of Mexico and a collision coast along the Pacific, each of which determine the characteristics of their coastal lagoons. The lagoons along the Gulf of Mexico are extensive, tropical and rich in seagrass beds and mangroves, and among these Laguna Madre has 84 species of fishes. In contrast, the lagoons along the Pacific are small, closed, mostly oligohaline and usually lack seagrass beds, and among these Laguna Salinas del Padre has 19 species of fishes. This marked difference in species richness, in turn, has a direct effect on the size and value of the fisheries, as these are regional in the first case and local and seasonal in the second.  相似文献   

5.
Pogue MG 《ZooKeys》2010,(52):57-64
Schinia psamatheasp. n. is described from the southern coastal plain in Georgia and the East Gulf coastal plain in Florida and Alabama in habitats associated with sandy soil or dunes. Adult males and females and their genitalia are described and illustrated. Schinia psamathea is compared to Schinia saturata (Grote).  相似文献   

6.
海岸带地区是元素循环最活跃的自然区域之一,微生物作为地球元素循环的主要驱动者,对该区域生态系统中物质转化与能量流动起着至关重要的作用。本文从典型海岸带生态系统:海岸带湿地、海草床与海藻森林、近岸水体出发,围绕微生物参与的碳、氮循环过程以及其中的温室气体排放情况,综述了在全球气候变化与人为活动干扰的作用下,海岸带地区的微生物群落对外界环境变化的响应机制以及生态功能维持机制,最后对海岸带系统中微生物生态研究进行了初步的展望。  相似文献   

7.
Less than 1% of Staphylinidae are known to be confined to coastal habitats. To explore the origins of coastal colonization within the tribe Athetini Casey, we present a revised molecular phylogeny. The dataset comprised partial mitochondrial COI, COII, 16S rDNA, NADH1, partial nuclear 18S rDNA and 28S rDNA. We chose a total of 95 species in 51 genera, including 14 coastal species in eight genera and 21 outgroup species from other aleocharine tribes. The concatenated dataset was analysed simultaneously by both parsimony‐ and model‐based (Bayesian and maximum likelihood) methods. The tribe Athetini was not supported as a monophyletic group, but together with the tribes Tachyusini, Ecitocharini and Hygronomini did form a monophylum. The ecological association of species with a coastal habitat was mapped onto a phylogeny to assess the evolution of habitat specialization in the Athetini lineage. The results reveal that five independent origins of coastal colonization have occurred throughout the tribe Athetini: (a) Osakatheta + Adota minuta + coastal Atheta (Badura) (clade A); (b) Adota (clade B); (c) Pontomalota + Tarphiota + Thinusa (clade C); (d) Iotarphia (clade D); and (e) Psammostiba (clade E). The low species number of the coastal Athetini compared with the entire Athetini lineage indicates that coastal habitats are harsh environments and so only a few species were able to colonize this habitat. The following changes in classification are proposed: (a) Ad. minuta Lee and Ahn is removed from the genus Adota and tentatively included in Atheta (Badura); (b) The genus Saphocallus Sharp is transferred from Athetini to Geostibini.  相似文献   

8.
M. Maeda  N. Taga 《Hydrobiologia》1981,76(1-2):49-55
Deoxyribonuclease (DNase) activity in seawater of Tokyo Bay was determined during 1972 and 1973. The activity was dependent on substrate (deoxyribonucleic acid) concentration within the range from o to io mg/l. During the summer the activity was high in the inner part of the bay and decreased on approaching the mouth of the bay. The intensity of activity was very high compared with the standing crop of particulate deoxyribonucleic acid (DNA) and this high activity corresponded with rapid decrease of the amount of nucleic acid with increasing depth in the water columns in the bay.During the investigation carried out in 1972 the activity fluctuated, being weak in May and November and high during the summer months. The profiles for activity did not coincide with those for chlorophyll-a, particulate DNA and seston, except in September. These non-parallel relations are discussed in terms of the distribution patterns of phytoplankton and bacteria.  相似文献   

9.
苏北海岸带有孔虫Ammonia beccarii微环境分布的初步研究   总被引:1,自引:0,他引:1  
本文通过对苏北海岸从北到南采样,统计有孔虫的个数,着重分析Ammonia beccarii(毕克卷转虫),并结合样品粒度分析、化学分析,试图寻找这单一属种的分布规律,发现.Ammonia beccarii的丰度、活体百分含量、优势度沿海岸线变化与有孔虫群的变化有较好的对应关系,但优势度在有孔虫群落中并不明显,基本在20%以下;Ammonia beccarii在分布上有如下特征:滩面上丰度与活体百分含量较大,在海滩、河口环境较小,在人工泻湖中极大;在南北方向上的分布变化没有显著规律;在沉积物中,一般在中值粒径较小(Mdφ≤0.8)或较大(Mdφ≥5.44)的沉积物中,Ammonia beccarii是不适宜生长的;另外,有机质含量可能是限制.Ammonia beccarii生长的一个条件。  相似文献   

10.
11.
杜荻  吕永龙  陈春赐  曹天正 《生态学报》2022,42(12):4719-4728
海岸带生态系统为人类提供了食物、水等丰富的物质以及文化、休闲等生态系统服务。但由于全氟化合物等污染物的排放和气候变化的影响,海岸带地区环境日益恶化、资源枯竭、极端气候灾害加剧。这些问题直接导致了海岸带水质下降、近海生物多样性减少、生物群落结构变化,海岸带生态系统可持续发展受到影响。全氟化合物在自然环境中难以降解,会沿食物链在生物体内累积和放大进而对人类健康造成风险。随着氟化工产业在我国的快速发展、新型全氟化合物的不断更替以及气候变化的加剧,全氟化合物对海岸带生态的影响面临着极大的不确定性。为了更好地服务海岸带生态系统的可持续发展,目前仍需要加快完善立法保障,在全国范围内对全氟化合物进行监测;将海洋与陆地作为一个有机整体,统筹陆地影响和海岸带管控,严格控制污染物的排放。  相似文献   

12.
Summary

An overview of the water quality status of False Bay identified the bacterial/viral water quality of stormwater and rivers discharging near contact recreation beaches to be the management concern of highest priority. A second water quality concern is the potential impact of nutrients being discharged into False Bay on the surf zone and bay ecosystems. Heavy metals, hydrocarbons and industrial chemical discharges into the Bay are not regarded as a serious water quality threat. Much of the future development planned for Metropolitan Cape Town will impact on the volume and water quality of rivers, groundwater, stormwater and wastewater flowing into False Bay; hence the need for an integrated catchment management approach to the management of the bay.

An assessment of the constraints facing the holistic management of the bay and catchment concludes that the four main concerns are: (1) a lack of key research information on the options for stormwater management, and on the loading and potential impacts of nutrients being discharged into the surf zone and bay ecosystems; (2) jurisdictional fragmentation, and the lack of coordinated policy and planning between different local and government authorities and other users; (3) legislative fragmentation; and (4) a lack of private sector and public consultation by authorities. Preliminary ideas on the structure of a management body for False Bay and its catchment which address the concerns listed above are presented.  相似文献   

13.
A summary is presented of estimates of distribution and growth of filamentous algae and its effect on the structure and functioning of epibenthic fauna and fish communities in shallow bays on the Swedish west coast. As a consequence of coastal eutrophication vegetation cover has gradually increased during the last decade, and during 1990's most bays in the Skagerrak-Kattegat area were variously covered with filamentous algae during spring and summer (May–July). In some areas filamentous algae (mainlyCladophora andEnteromorpha) completely covered the bottom. In field studies it was demonstrated that increased cover and dominance of filamentous algae result in structural changes of the epibenthic fauna community. Field studies showed that species richness and biomass of epibenthic fauna increased in a sandy bay with a moderate increase (30 to 50%) of filamentous algae cover. At higher cover (90%), biomass of epibenthic fauna was reduced, however, to the same level as for the sandy habitat, although the dominant epibenthic species were different. Heavy growth of epiphytic filamentous algae on eelgrass resulted in reduced biomass and a shift in the species composition of the epibenthic fauna community. Fish assemblage structure was also related to changes in vegetation. In eelgrass beds, fish species numbers were reduced with increasing cover of epiphytic filamentous algae, and at rocky bottoms with kelp algae (dominated byFucus), fish biomass decreased with increasing cover of attached filamentous algae. Further, foraging efficiency of juvenile cod and settling success of plaice were reduced as a response to increasing dominance of filamentous algae.  相似文献   

14.
J. G. Shiber 《Hydrobiologia》1981,83(2):181-195
Trace metal concentrations were determined in six species of intertidal organisms common to the coast of Ras Beirut, Lebanon. Lead, cadmium, nickel, iron, and zinc were highest in the polychaete,Hermodice carunculata, but the eggs of the sea urchin,Arbacia lixula, had similar iron levels and the sea anemone,Actinia equina, had zinc concentrations which also approached levels in the polychaete. The highest copper occurred in the shore crab,Pachygrapsus transversus, while chromium was highest in the eggs ofArbacia lixula.Cystoseira spinosa, the only alga studied, had average copper and iron concentrations similar to those found in the same species in another study. Together with the sea urchin eggs,C. spinosa exhibited the most variable zinc levels in the present investigation. The fish,Thalassoma pavo, which is rather common along the rocky coastal areas of Lebanon, appeared to have fairly high concentrations of certain elements in relation to levels reported in species of fish from other locations.Sewage, garbage, industrial and agricultural waste materials all enter the Mediterranean from Lebanon without prior treatment, which along with increased land erosion, probably contribute substantially to the availability of metals to the biota studied. It is suggested that more work on trace elements in coastal organisms from the eastern Mediterranean basin be undertaken before any conclusive statements are made. Such work should also investigate the various physiological and biochemical factors involved in metal uptake and retention by each species.  相似文献   

15.
T. Lam Hai 《Hydrobiologia》1985,128(2):161-174
A monthly zooplankton survey has been conducted from March 1982 to March 1983 at three shallow stations of Thau, a northern-mediterranean lagoon. These stations differ by their distance from the entry of sea-water in the lagoon. Parameters such as pH, temperature, dissolved oxygen, conductivity and turbidity have been measured simultaneously with the sampling in the same water layer. The zooplankton collected corresponds to species usually found in marine neritic communities. In the spring, species richness is maximum. During the summer, meroplankton forms dominant populations in the communities. Autumn is marked by a reduction of the number of species and of the abundance in both components, holoplankton and meroplankton. Few species are present in the winter holoplankton while meroplankton disappears practically from the samples. The sites under observation are subjected to unpredictable changes, in water movement as well as in the organization of the zooplankton communities. These modifications are strongly influenced by weather conditions.  相似文献   

16.
Chua Thia-Eng 《Hydrobiologia》1997,352(1-3):159-166
Coastal environmental management requires timely and appropriate policy, management and technological interventions to address a host of interrelated environmental problems arising from unplanned and unregulated coastal developments. These interventions can only be effective if they are based on sound scientific (including socioeconomic) information. Thus, science plays a significant role in the environmental management of coastal and marine areas. This paper highlights the essential components of environmental coastal management that require scientific interventions, particularly in providing the scientific basis for policy interventions, and preventive and/or mitigating measures. The integration and packaging of scientific information for management actions require an interdisciplinary effort to address identified management problems. Scientific research should respond to management needs and make contributions to the better understanding of ecosystems and their responses to human interventions. Scientific information urgently required for management includes an understanding of interactions in coastal resource systems, identification, evaluation and prioritization of management issues, management strategies and actions, and development of methodologies and tools for environmental management. Obstacles to management-oriented research have also been identified to include defective perception among scientists, defective communication between scientists and decision makers, intellectual and cultural arrogance, and inadequate technical and management capability at the local level. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
Anthropogenic activities on coastal watersheds increase nutrient concentrations of groundwater. As groundwater travels downslope it transports these nutrients toward the adjoining coastal water. The resulting nutrient loading rates can be significant because nutrient concentrations in coastal groundwaters may be several orders of magnitude greater than those of receiving coastal waters. Groundwater-borne nutrients are most subject to active biogeochemical transformations as they course through the upper 1 m or so of bottom sediments. There conditions favor anaerobic processes such as denitrification, as well as other mechanisms that either sequester or release nutrients. The relative importance of advective vs. regenerative pathways of nutrient supply may result in widely different rates of release of nutrients from sediments. The relative activity of denitrifiers also may alter the ratio of N to P released to overlying waters, and hence affect which nutrient limits growth of producers. The consequences of nutrient (particularly nitrate) loading include somewhat elevated nutrient concentrations in the watercolumn, increased growth of macroalgae and phytoplankton, reduction of seagrass beds, and reductions of the associated fauna. The decline in animals occurs because of habitat changes and because of the increased frequency of anoxic events prompted by the characteristically high respiration rates found in enriched waters.  相似文献   

18.
Jost  Günter  Pollehne  Falk 《Hydrobiologia》1997,352(1-3):107-115
This paper presents the results of a long-term survey of the hydrography, nutrients and phytoplankton in Tolo Harbour carried out between 1982 and 1992. Some nutrients such as total inorganic nitrogen, ammonia and total phosphorus increased during the 10 year period, but chlorophyll a, which indicated algal biomass, did not show an increasing trend. The phytoplankton of Tolo Harbour consisted largely of diatoms. Dinoflagellates and minor algal groups such as cryptomonads and small flagellates constituted a smaller fraction of the phytoplankton population. Densities of diatoms and minor algal groups increased in some stations, but the density of dinoflagellates remained relatively unchanged during the study period. Most nutrient variables were negatively correlated with densities of diatom and total phytoplankton, and positively correlated with densities of minor algal groups. While dinoflagellate densities were positively correlated with total nitrogen in some stations, no correlation existed between dinoflagellate density and most of the nutrient variables. Our results show that there is a gradual change in phytoplankton community in Tolo Harbour,most notably in the nutrient-rich inner harbour waters, with the smaller algae assuming increasing abundance. Thus there was a net increase in density of total phytoplankton even though chlorophyll a concentrations did not increase. No evidence was found in this study to show that increased nutrient loading would inevitably lead to increase in densities of dinoflagellates in Tolo Harbour. Instead, dinoflagellate densities showed stronger correlations with physical variables such as temperature, pH and salinity. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

19.
Sea level rise (SLR) threatens coastal wetlands worldwide, yet the fate of individual wetlands will vary based on local topography, wetland morphology, sediment dynamics, hydrologic processes, and plant‐mediated feedbacks. Local variability in these factors makes it difficult to predict SLR effects across wetlands or to develop a holistic regional perspective on SLR response for a diversity of wetland types. To improve regional predictions of SLR impacts to coastal wetlands, we developed a model that addresses the scale‐dependent factors controlling SLR response and accommodates different levels of data availability. The model quantifies SLR‐driven habitat conversion within wetlands across a region by predicting changes in individual wetland hypsometry. This standardized approach can be applied to all wetlands in a region regardless of data availability, making it ideal for modeling SLR response across a range of scales. Our model was applied to 105 wetlands in southern California that spanned a broad range of typology and data availability. Our findings suggest that if wetlands are confined to their current extents, the region will lose 12% of marsh habitats (vegetated marsh and unvegetated flats) with 0.6 m of SLR (projected for 2050) and 48% with 1.7 m of SLR (projected for 2100). Habitat conversion was more drastic in wetlands with larger proportions of marsh habitats relative to subtidal habitats and occurred more rapidly in small lagoons relative to larger sites. Our assessment can inform management of coastal wetland vulnerability, improve understanding of the SLR drivers relevant to individual wetlands, and highlight significant data gaps that impede SLR response modeling across spatial scales. This approach augments regional SLR assessments by considering spatial variability in SLR response drivers, addressing data gaps, and accommodating wetland diversity, which will provide greater insights into regional SLR response that are relevant to coastal management and restoration efforts.  相似文献   

20.
三大沿海城市群滨海湿地的陆源人类活动影响模式   总被引:2,自引:0,他引:2  
王毅杰  俞慎 《生态学报》2013,33(3):998-1010
随着陆源人类活动对滨海湿地的干扰日益强烈,研究滨海湿地陆源人类活动影响规律对于滨海湿地资源管理和保护具有重要的现实意义.以我国三大沿海城市群(环渤海湾、长江三角洲、珠江三角洲)滨海湿地为研究对象,分别选取围海造地(直接因子)和流域污染物(营养盐、非点源无机污染物)输入(间接因子)表征1990-2000年间滨海湿地的陆源人类活动影响强度及规律.研究发现,虽然围海造地仍然以农业用地为主(>50%),但城市建设用地比例随人口城市化率增高而增加,以珠江三角洲城市群最高;在环渤海湾和珠江三角洲城市群区域超过60%的滨海湿地面积受到高或中等污染物输入强度影响,长江三角洲城市群区域则有44.7%的滨海湿地面积处于中等污染物输入强度及以上.通过叠加围海造地和污染物输入双重陆源人类活动的综合影响强度表明,珠江三角洲城市群平均强度指数达到0.79,且处于中等及以上影响强度区域面积比例达到78%,均高于其他两个城市群滨海湿地区域.空间分析结果表明,陆源人类活动对滨海湿地的强影响区域多集中分布于河流人海口、较为发达城市滨海区以及海岸线附近.  相似文献   

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