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1.
Wetland biodiversity means mainly the types of wetland ecosystem and biological species diversity. Biodiversity includes all species of plants, animals and microbes, all gene possessed by them and all ecosystems consisting of them and environment. According to the origin and genesis, China’s wetlands can be divided into natural wetland ecosystems including mires, lakeshores, bottomland, seashore, wet meadow, etc., and artificial wetland ecosystem including paddy field. Then based on geomorphological type, these ecosystems can be divided into 15 subsystems, then based on soil substrata and ecological niche conditions, they can be subdivided into 15 classes, finally according to construction species of plants, several types can be divided into. They are not only the expression of ecosystem diversity, but also the base for biological communities subsistence. This peculiar ecological niche provides a complex and perfect special habitat for various animal and plant communities. In this special habitat, there exist various biological types from monomolecular microbes to higher plants and animals, especially some endangered and rare plants and animals. According to the statistics, there are more than 300 species of birds in China wetlands, making up one-third of the total number of China’s birds. Wetlands not only good place for waterbirds living, but also the important environment on which wild animals and plant rely for existence. There are 65 species of mammals, 50 species of reptiles, 45 species of amphibious animals, 1040 species of fish, 825 species of higher plants, 639 species of angiosperm, 10 species of gymnosperm, 12 species of pteridophyte and 164 species of bryophyte investigated in China’s wetlands.  相似文献   

2.
STUDY ON WETLAND BIODIVERSITY IN CHINA   总被引:5,自引:0,他引:5  
STUDYONWETLANDBIODIVERSITYINCHINA吕宪国,王荣芬STUDYONWETLANDBIODIVERSITYINCHINA¥LuXianguo;WangRongfen(ChangchunInstituteofGeography...  相似文献   

3.
Wetland research has become a hot spot linking multiple disciplines presently. Wetland classification and mapping is the basis for wetland research. It is difficult to generate wetland data sets using traditional methods because of the low accessibility of wetlands, hence remote sensing data have become one of the primary data sources in wetland research. This paper presents a case study conducted at the core area of Honghe National Nature Reserve in the Sanjiang Plain, Northeast China. In this study, three images generated by airship, from Thematic Mapper and from SPOT 5 were selected to produce wetland maps at three different wetland landscape levels. After assessing classification accuracies of the three maps, we compared the different wetland mapping results of 11 plant communities to the airship image, 6 plant ecotypes to the TM image and 9 landscape classifications to the SPOT 5 image. We discussed the different characteristics of the hierarchical ecosystem classifications based on the spatial scales of the different images. The results indicate that spatial scales of remote sensing data have an important link to the hierarchies of wetland plant ecosystems displayed on the wetland landscape maps. The richness of wetland landscape information derived from an image closely relates to its spatial resolution. This study can enrich the ecological classification methods and mapping techniques dealing with the spatial scales of different remote sensing images. With a better understanding of classification accuracies in mapping wetlands by using different scales of remote sensing data, we can make an appropriate approach for dealing with the scale issue of remote sensing images.  相似文献   

4.
Multiple natural and human factors in estuarine wetlands result in complicated land surface characteristics with distinct spatial and temporal heterogeneities, thereby contributing to the difficulty in identifying spatiotemporal variations and influencing factors of plant diversity. A unique estuarine wetland gradient system(UEWGS) consisting of soil, vegetation, heat, distance, landscape, and anthropogenic gradients was established based on the ecological features of estuarine wetland through remote sensing and field investigation methods. It resolved the complicated land surface characteristics, covered all aspects of factors influencing plant diversity, and possessed distinct spatiotemporal heterogeneities. The Yellow River Delta, the largest estuarine wetland in the northern China, was selected as the study area to demonstrate UEWGS in four seasons in 2017. A total of 123 species were recorded with considerable seasonal difference. Phragmites australis, Suaeda salsa, and Tamarix chinensis were the dominant species, and crop species also played important roles. In single effect, all aspects of gradients exerted significant influences, yet only vegetation gradient possessed significant influences in all seasons. In comprehensive effect, soil, vegetation, heat, and distance gradients showed significant gross influences. Moisture content in soil gradient and net primary productivity in vegetation gradient possessed significant net influences in all seasons and can be considered as the main driving factor and indicator, respectively, of plant diversity. The results validated the significance of UEWGS in revealing the plant diversity spatiotemporal characteristics and influencing factors, and UEWGS possessed universal applicability in the spatiotemporal analysis of plant diversity in estuarine areas.  相似文献   

5.
As an important indicator of the structural and functional stability of wetland landscapes, hydrological connectivity plays an important role in maintaining the stability of wetland ecosystems. Large-scale human activities have led to significant changes in the hydrological connectivity pattern of wetlands in Naoli River Basin since 1950 s. Combined with the availability of wetland habitat and the spreading capacity of aquatic birds, hydrological connectivity indices of marsh wetlands were calculated in the studied area, and the temporal and spatial changes were analyzed from 1950 s to 2015. The results indicate that:(1) the hydrological connectivity index of the marsh wetlands shows a growth trend with increasing distance threshold. All patches of marsh wetlands linked together when the distance threshold reached 35--40 km;(2) the optimal distance of hydrological connectivity is about 10 km for marsh wetlands of whole Naoli River Basin;(3) the total hydrological connectivity of marsh wetlands decreased in the Naoli River Basin from 1950 s to 2015. Although the hydrological connectivity index increased after 2005, the fragmentation of the landscape has not been improved. The analysis of the wetland hydrological connectivity can provide a scientific basis for the ecological restoration and protection of the wetland in the Naoli River Basin.  相似文献   

6.
Amplicon sequencing of functional genes is a powerful technique to explore the diversity and abundance of microbes involved in biogeochemical processes. One such key process, denitrification, is of particular importance because it can transform nitrate(NO3-) to N2 gas that is released to the atmosphere. In nitrogen limited alpine wetlands, assessing bacterial denitrification under the stress of wetland desertification is fundamental to understand nutrients, especially nitrogen cycling in alpine wetlands, and thus imperative for the maintenance of healthy alpine wetland ecosystems. We applied amplicon sequencing of the nirS gene to analyze the response of denitrifying bacterial community to alpine wetland desertification in Zoige, China. Raw reads were processed for quality, translated with frameshift correction, and a total of 95,316 nirS gene sequences were used for rarefaction analysis, and 1011 OTUs were detected and used in downstream analysis. Compared to the pristine swamp soil, edaphic parameters including water content, organic carbon, total nitrogen, total phosphorous, available nitrogen, available phosphorous and potential denitrification rate were significantly decreased in the moderately degraded meadow soil and in severely degraded sandy soil. Diversity of the soil nirS-type denitrifying bacteria communities increased along the Zoige wetland desertification, and Proteobacteria and Chloroflexi were the dominant denitrifying bacterial species. Genus Cupriavidus(formerly Wautersia), Azoarcus, Azospira, Thiothrix, and Rhizobiales were significantly(P0.05) depleted along the wetland desertification succession. Soil available phosphorous was the key determinant of the composition of the nirS gene containing denitrifying bacterial communities. The proportion of depleted taxa increased along the desertification of the Zoige wetland, suggesting that wetland desertification created specific physicochemical conditions that decreased the microhabitats for bacterial denitrifiers and the denitrification related genetic diversity.  相似文献   

7.
Invasive plant species are exerting a serious threat to biological diversity in many regions of the world. To understand plant invasions this study aims to test which of the two plant invasiveness hypotheses; ‘low native diversity' vs. ‘high native diversity', is supported by the regional distribution patterns of invasive plant species in the Himalayas,Nepal. This study is based on data retrieved from published literatures and herbarium specimens. The relationship between invasive plant species distribution patterns and that of native plant species is elucidated by scatter plots, as well as by generalized linear models. The native plant species and invasive plant species have similar distribution patterns and the maximum number of invasive plant species is found in the same altitudinal range where the highest richness for native tree species is found. There is a clear trend of higher invasive plant richness in regions where native tree species richness is relatively high.Consequently, the native plant richness is highest in the central phytogeographic region, followed by the eastern and the western regions, respectively. The invasive plant species also follows a similar trend.Additionally, the invasive plant species richness was positively correlated with anthropogenic factors such as human population density and the number of visiting tourists. This study supports the hypothesis that ‘high native diversity' supports or facilitates invasive plant species. Further, it indicates that nativeand invasive plant species may require similar natural conditions, but that the invasive plant species seem more dependent and influenced by anthropogenic disturbance factors.  相似文献   

8.
基于加权Voronoi图的北京市湿地功能分区研究   总被引:1,自引:0,他引:1  
湿地功能分区是城市湿地生态系统健康恢复、管理改善,以及资源可持续利用的重要前提。本文以北京湿地为例,利用客观赋权的主成分分析法对湿地生态服务功能进行综合评价;并结合空间分析中的Voronoi图空间分区方法,通过利用牛顿-断裂点模型确定属性权重的主要步骤,构建基于加权Voronoi图的城市湿地功能分区模型,开展"自下而上"定量化的北京湿地功能分区研究。结果表明:(1)北京湿地功能综合评价中,密云水库湿地的功能综合值最大,表明该湿地生态服务功能作用最重要。(2)北京湿地功能分区分为三级框架,其中包括4个一级核心湿地功能区、15个二级核心湿地功能区、43个三级核心湿地单元。(3)湿地资源功能价值量与湿地斑块空间关系的相结合,实现了属性和空间双重距离约束的湿地功能分区,促进了湿地生态系统服务价值评估在决策管理中的深入应用,为城市湿地功能区划提供技术支持。  相似文献   

9.
The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau river ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and river ecology. In this study, the composition, abundance, and diversity of periphytic protozoa were investigated across four seasons from 2008 to 2009 to better understand their spatio-temporal patterns and relationship to the environment. Our investigation shows that periphytic protozoa in the Niyang River contained 15 genera, belonged to Tubulinea, Alveolata, Discosea and Rhizaria, Alveolata possessed most genera, up to nine, with highest share in abundance, exceeding 50%, Difflugia and Glaucoma were dominant genera. Moreover, four diversity indices of periphytic protozoa, including species richness, total abundance, Shannon-Wiener diversity index and Pielou's evenness index, displayed a significant descending trend as the seasons continued, in the order of winter, spring, summer and autumn; with a significant difference existing between winter and summer(or autumn) for Shannon-Wiener diversity index and species richness( P 0.05). Four of these diversity indices also presented a V-shaped pattern between the upper middle course of the Niyang River and the confluence of the Niyang River and Yarlung Zangbo River, with the lowest value occurred in the middle course of the Niyang River. However, no significant variation was found through the Niyang River( P 0.05). In addition, canonical correlation analysis(CCA) shows that the densities of Difflugia, Glaucoma is, Enchelydium, Cyphoderia, and Enchelys correlate with water temperature, alkalinity, hardness, pH, and dissolved oxygen, respectively. Lastly, the relationship between periphytic protozoa diversity and the environmental factors of the Niyang River can be predicted using classification and regression trees(CART) annalysis, which suggests that the total abundance and Shannon-Wiener diversity index would be higher when the elevation is above 3 308 m. On the other hand, the Shannon-Wiener diversity index and Pielou's evenness index would be lower when pH and ammoniacal nitrogen have lower or higher values. Finally yet importantly, close attention should be paid to periphytic protozoa and its environment to ensure sustainable development of the Niyang River ecosystem.  相似文献   

10.
Four soil types(peat, marsh, meadow, and sandy) in the Zoige Plateau of China are associated with the severity of wetland degradation. The effects of wetland degradation on the structure and abundance of fungal communities and cellulase activity were assessed in these 4 soil types at 3 depths using DGGE(Denatured Gradient Gel Electrophoresis), q PCR(Quantitative Real-time PCR),and 3,5-dinitrosalicylic acid assays. Cellulase activity and abundance of the fungal community declined in parallel to the level of wetland degradation(from least to most disturbed). DGGE analysis indicated a major shift in composition of fungal communities among the4 soil types consistent with the level of degradation.Water content(WC), organic carbon(OC), total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were strongly correlated with cellulase activity and the structure and abundance of the fungal community.The results indicate that soil physicochemical properties(WC, OC, TN, TP, AN, and AP), cellulase activity, and diversity and abundance of fungal communities are sensitive indicators of the relative level of wetland degradation. WC was the major factorinvolved in Zoige wetland degradation and lower WC levels contributed to declines in the abundance and diversity of the fungal community and reduction in cellulase activity.  相似文献   

11.
STUDY ON WETLAND LOSS AND ITS REASONS IN CHINA   总被引:2,自引:2,他引:0  
1INTRODUCTIONWetlandsaretheecosystemswithmanyfunctionsandhavebeenprovidinguswitharangeoffunctionsandbenefitssuchaswatersupplyflowregulationsendimentretentionmoderationofclimatepreventionofsalinewaterintrusionetc.Althoughwetlandoccupyonlyabout6%…  相似文献   

12.
Species diversity exhibit a close relationship with ecosystem services, and making clear the relationship can help us understand the service value and functional mechanism of ecosystems and take measures to promote human well-being. Here, we used species survey data and multi-source habitat factors to simulate the spatial distribution of species richness and four types of ecosystem services(water production, net primary productivity, carbon storage, and habitat quality) in Sanjiangyuan National Park located in Qinghai Province, China. We also analyzed the spatial distribution pattern and explored the spatial relationship between species richness and ecosystem services through Geo Detector analyses. We found that high species richness in Sanjiangyuan National Park was shown to be mainly distributed in areas with high vegetation growth on both sides of rivers. The effect of climate on the spatial distribution of species richness in the park is the highest among all the selected environmental variables. For the relationship between species diversity and ecosystem services, the relative correlation strength of single ecosystem service varied among the three main ecosystems(grassland, meadow, and wetland) and all relations are positive.  相似文献   

13.
The Qinghai-Tibet Plateau encompasses a large quantity of wetlands, some of which have been degraded to varying severity levels. In the literature, a number of degradation indicators have been proposed to evaluate ecological health of wetlands, but their effectiveness in the plateau environment remains unknown. In this study, we assessed the effectiveness of three degradation indicators, soil moisture content at 10 cm deep, vegetative cover, and density of pika burrows. The degradation severity of wetlands in Maduo County on the Qinghai-Tibet Plateau is enumerated at four levels, intact, slight, moderate and severe. Analysis of 106 samples collected in the field demonstrates that the density of pika burrows is the least reliable indicator. By comparison, vegetative cover and underlying soil moisture content are more reliable, even though neither is a perfect indicator as the difference among adjacent levels of severity as revealed by t-test is not always statistically significant. The imperfection of vegetative cover as an indicator is due to its variation among different types of wetlands. The limitation of moisture content is attributed to its non-linear relationship with wetland degradation. Above the threshold of about 50% in moisture content wetlands are unlikely to be degraded. It is recommended that moisture be measured at the point near the surface and vegetative cover be further differentiated by species in order to improve their effectiveness.  相似文献   

14.
The alpine wetlands in QTP(Qinghai-Tibetan Plateau) have been profoundly impacted along with global climate changes. We employ satellite datasets and climate data to explore the relationships between alpine wetlands and climate changes based on remote sensing data. Results show that: 1) the wetland NDVI(Normalized Difference Vegetation Index) and GPP(Gross Primary Production) were more sensitive to air temperature than to precipitation rate. The wetland ET(evapotranspiration) across alpine wetlands was greatly correlated with precipitation rate. 2) Alpine wetlands responses to climate changes varied spatially and temporally due to different geographic environments, variety of wetland formation and human disturbances. 3) The vegetation responses of the Zoige wetland was the most noticeable and related to the temperature, while the GPP and NDVI of the Qiangtang Plateau and Gyaring-Ngoring Lake were significantly correlated with both temperature and precipitation. 4) ET in the Zoige wetland showed a significantly positive trend, while ET in Maidika wetland and the Qiangtang plateau showed a negative trend, implying wetland degradation in those two wetland regions. The complexities of the impacts of climate changes on alpine wetlands indicate the necessity of further study to understand and conserve alpine wetland ecosystems.  相似文献   

15.
The high Zoige Basin (Ruoergai Plateau) on the eastern Tibetan Plateau is a fault depression formed during intensive uplifting of the Tibetan Plateau. The wetland is globally important in biodiversity and is composed of marshes, bogs, fens, wet meadows and shallow water interspersed with low hills and sub-alpine meadows. Most of the Zoige wetlands have long been one of the most important grazing lands in China. Recent rangeland policy has allowed grazing, and usable wetland areas have been being legally allocated to individuals or groups of households on a long-term lease basis. Privatizafion of the wetland has impacted the Zoige wetlands in aspects of hydrologic condition, landscape and biodiversity. The uneven spatial distribution of water resources onprivatelands has led to the practice of extracting ground water, which has decreased the perched water table in Zoige. Fencing off the rangelands and grazing on expanding sand dunes have affected landscapes. Variation in the water table has led to the changes in vegetation diversity, resulting in the changes in wildlife and aquatic diversities and ecosystem processes. Making use all year round of the pasture that was previously grazed only in summer has shrunk the daily activity space of wildlife, and the newly erected fences blocked the movement of wild animals looking for food in the snow to lower and open areas. To maintain the favorable conditions of the Zoige wetland ecosystem, the author suggests that, in addition to biophysical research and implementation of conservation practices, there is an immediate need to initiate an integrated management program, increase public awareness of wetland functions and provide better training for the local conservation staff.  相似文献   

16.
Accurate wetland delineation is the basis of wetland definition and mapping, and is of great importance for wetland management and research. The Zoigê Plateau on the Qinghai-Tibet Plateau was used as a research site for research on alpine wetland delineation. Several studies have analyzed the spatiotemporal pattern and dynamics of these alpine wetlands, but none have addressed the issues of wetland boundaries. The objective of this work was to discriminate the upper boundaries of alpine wetlands by coupling ecological methods and satellite observations. The combination of Landsat 8 images and supervised classification was an effective method for rapid identification of alpine wetlands in the Zoigê Plateau. Wet meadow was relatively stable compared with hydric soils and wetland hydrology and could be used as a primary indicator for discriminating the upper boundaries of alpine wetlands. A slope of less than 4.5° could be used as the threshold value for wetland delineation. The normalized difference vegetation index(NDVI) in 434 field sites showed that a threshold value of 0.3 could distinguish grasslands from emergent marsh and wet meadow in September. The median normalized difference water index(NDWI) of emergent marsh remained more stable than that of wet meadow and grasslands during the period from September until July of the following year. The index of mean density in wet meadow zones was higher than the emergent and upland zones. Over twice the number of species occurred in the wet meadow zone compared with the emergent zone, and close to the value of upland zone. Alpine wetlands in the three reserves in 2014 covered 1175.19 km2 with a classification accuracy of 75.6%. The combination of ecological methods and remote sensing technology will play an important role in wetland delineation at medium and small scales. The correct differentiation between wet meadow and grasslands is the key to improving the accuracy of future wetland delineation.  相似文献   

17.
Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteristics of changes in wetland plant communities in two of the largest lakes in Yunnan Province, Dianchi and Erhai lakes. We collected records of native and alien plant communities in the two lakes from literature published from the 1950s to current period. We calculated plant community types and their area in some historical periods when related data were reported, and analyzed the relationship between changes in plant communities and water pollution. In Dianchi Lake, 12 community types of native plant communities, covering over 80% of the surface in the 1950s and 1960s, were reduced to four types covering 2.4% by the late 2000s. Alien plant communities started to appear in the lake in the late 1970s, and have since come to cover 4.9% of the lake surface, thereby becoming dominant. In Erhai Lake, 16 community types of native plant communities, covering 47.1% of the lake surface in the late 1970s, declined to 10 community types, covering 9.3% of the surface, by the late 2000s. Alien plant communities appeared in the middle 1980s, and at present cover 0.7% of the surface area. It was indicated that changes in plant communities were significant related to water eutrophication. The area occupied by native and alien plant communities was, respectively, negatively and positively related to the content of nutrients in water. This showed lacustrine pollution played an important role in native plant loss and alien plant invasion in the two plateau lakes.  相似文献   

18.
Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional ecological security greatly. Since the 21 th century, returning farmlands to wetlands was widely adopted for natural restoration in the Sangjiang Plain. As the first reflection of wetland restoration, vegetation succession of restored D. angustifolia wetlands should be fully assessed. In this study, vegetation investigation was carried out in three restored D. angustifolia wetlands with 5, 8 and 12 yr restoration, respectively. Meanwhile, a natural D. angustifolia wetland was selected as reference wetland. Results showed that community composition changed greatly and there was visible community succession. Community dominant species changed from composite to gramineae as restoration time increasing.At first, weeds community appeared in the restored wetlands, especially the xerophytes developed to the pioneer species rapidly. And then, mesophytes and wetland species became the dominant species in the restored wetlands. Finally, wetland species, especially D. angustifolia, occupied the dominant position of restored community. Shannon-wiener index(H) and Simpson index(D) both decreased to close to natural D. angustifolia wetlands. Compared with natural D. angustifolia wetland, species composition and diversity in restored wetlands were more complex and higher. As restoration time increasing, there were not significant differences between community characteristics of restored wetlands and natural wetland. All these suggested that vegetation in reclaimed D. angustifolia wetland could be restored naturally, but its restored period is 10 yr at least. From another angle, it is important to protect current natural wetlands.  相似文献   

19.
Decades of commercial planting and other anthropogenic processes are posing a threat to the riparian landscapes of the Cauvery river basin, which supports a high floral diversity. Despite this, the habitats in the upstream sections of the River Cauvery are still intact, as they are located in sacred groves. To understand the dynamism of riparian forests exposed to anthropogenic pressures, the upstream stretch of Cauvery extending from Kushalanagara to Talacauvery (~102 km) was categorized into two landscapes: agro ecosystem and sacred (i.e. preserved). The tree species were sampled using belt transects at 5 km intervals and the regeneration status of endemic species assessed using quadrats. A total of 128 species belonging to 47 families, and representing 1,590 individuals, was observed. Amongst them, 65% of unique species were exclusive to sacred landscapes. A rarefaction plot confirmed higher species richness for the sacred compared to the agro ecosystem landscapes, and diversity indices with more evenness in distribution were evident in sacred landscapes. A significant loss of endemic tree species in the agro ecosystem landscapes was found. Overall, this study demonstrates that an intense biotic pressure in terms of plantations and other anthropogenic activities have altered the species composition of the riparian zone in non-sacred areas. A permanent policy implication is required for the conservation of riparian buffers to avoid further ecosystem degradation and loss of biodiversity.  相似文献   

20.
In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We aimed to evaluate the patterns of biodiversity and structure of plant communities from rocky outcrops in high altitude grasslands of three areas at the Caparaó National Park, southeastern Brazil, by sampling 300 randomly distributed plots. Then, we compared the floristic composition, relative abundance, and biological and vegetation spectra among areas. We classified species as endemic and non-endemic and verified the occurrence of endangered species. Species richness was evaluated by rarefaction analysis on the sampling units. The importance value and species abundance distribution (SAD) models were assessed. We also performed an indicator species analysis. We sampled 58 species belonging to 49 genera and 32 families. The number of species decreased with increasing altitude, with significant differences being observed among areas regarding richness, abundance, and cover. Of the total number of species, 10 are endemic to the Caparaó National Park and 17 are listed on the Brazilian Red List of endangered species. The dominant families on all peaks were Asteraceae and Poaceae. The SAD models showed lognormal and geometric distributions, corroborating the fact that 10 species that were common to all three areas were also the most dominant ones in the communities and showed the highest importance values, which ranged between 35% and 60%. Indicator species analysis revealed that 28 species (48.27%) were indicators. Of these, 42.85% had maximum specificity, meaning that they occurred only in one area. Thus, the number of species per life form ratio was similar among areas, yet vegetation spectra differed, especially for hemicryptophytes. The altimetric difference among the areas showed to be a very important driver in the community assembly, influencing the evaluated variables, however, other drivers as soil depth, slope and water could also influence the community structure on a smaller and local spatial scale.  相似文献   

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