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1.
The vulnerability of coastal areas in the Alligator Rivers Region (northern Australia) to predicted climate change and potential sea level rise was assessed as part of a national study. The coastal area is composed of a number of estuarine and freshwater habitats that are intricately interlinked and can not be effectively managed in isolation of each other. The outcomes of the assessment focused on the floodplain environments of the region, but are also applicable to the broader wetland environments that occur across the northern Australian wet-dry tropics. The management regime in the region is based on traditional Aboriginal ownership of much of the land, which is leased to the federal government as a national park. Scientific research has been intensive; however, important questions have been raised about the collation and effective use of this information. The vulnerability assessment framework required effective use of this information and cooperation with the management authority to identify change scenarios and management and research responses. A climate change scenario was established as the basis for predicting biophysical change in the coastal and wetland environments. The predictions suggest that large-scale change will occur and many of the existing values derived from these areas (i.e., usage by traditional Aboriginal occupants, and nature conservation) could be degraded or even lost. Recommended management responses include the initiation of specific monitoring, empowerment of local bodies to take active management steps, and to increase awareness of the likely consequences of change. Further data coordination and review are needed to ascertain the validity of the predictions and the concomitant management responses.  相似文献   

2.
EARTH University is a small agronomic university with a theme of sustainability in eastern Costa Rica. Several natural and constructed wetlands on its campus are used for research, water quality improvement, and higher education. It has become an important location for research and teaching on humid tropical wetland ecology and management. A 112-ha flow-through Raphia taedigera (Arecaceae) forested wetland is being used for climate change research, focusing on carbon sequestration and methane generation. Methane emissions are measured seasonally and are comparable to rates in tropical wetlands published elsewhere. Carbon sequestration by the wetland appears to be substantially higher than similar flow-through temperate zone wetlands. Treatment wetlands are used on campus to improve water quality of effluents from an animal farm, a dairy plant, a landfill, and a banana paper plant. Water quality was substantially improved in all of these wetlands except the landfill leachate wetland. All of these campus wetlands have been integrated into the four-year education program of EARTH University and 22 undergraduate projects have been completed on wetlands over the past 14 years.  相似文献   

3.
Pollution of rivers is an increasing problem that affects biological diversity and structure of natural ecosystem. The present study reported the results of the preliminary analysis of diatom and macroinvertebrate communities of river Picentino (Italy, Campania) in respect of the WFD/60/2000/EC. Because of the sensitive to a variety of environmental factors the two categories of organism are used as excellent indicators of changes taking place in water ecosystems, especially eutrophication. Sampling of benthic diatoms and macroinvertebrates has been carried out in five stations along the river during April–May 2014 in order to apply the ICMi and the STAR_ICMi and assess river quality. The data showed a diversification in diatomic and macroinvertebrate communities in relation to environmental stresses and level of pollution, with the disappearance of species higher sensitive to eutrophication and organic load in the upper course of the river. River water quality was found to deteriorate from the upperstream to the downstream because of the increasing of human impact and the intensive agriculture activity along the river.We conclude that the monitoring of diatomic and macroinvertebrate communities could give detailed information about the ecological status of rivers. However it is necessary to increase the achieved data by monitoring other biological communities in order to define adequated strategies to save and preserve the rivers habitat.  相似文献   

4.
The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability . Here, we compare wetland conditions between two 30‐year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland ‐ dependent species.  相似文献   

5.
A survey of 18 watercourses of the Tiber River basin was carried out to define the ecological niche breadth of some aquatic bryophyte species in relation to environmental factors. Aquatic bryophytes were sampled and water environmental parameters were measured at 99 stations distributed along the catchment (from the headwater regions to the downstream reaches). The datasets of the collected species and environmental data were analyzed by using a multivariate statistical analysis (PCA biplot). Ecological responses of the recorded aquatic bryophytes were obtained using a fuzzy set approach, and were compared with data from literature. The results show that the presence of the aquatic bryophytes in watercourses is affected negatively by the reduction of water velocity, clearness, substratum size and the worsening quality of the water physico-chemical status. In fact, aquatic bryophytes show a general preference for stations characterized by medium-large granulometry, and fast-flowing, clear, oxygenated (mean value 9.2 mg/l), cool waters (mean value 15.0 °C), with low loads of nutrients, particularly ammonia (mean value 0.10 mg/l) and phosphates (mean value 0.09 mg/l). However, ecological responses reveal different patterns in the distribution of aquatic bryophyte species mainly in relation to water physico-chemical parameters (e.g. temperature, conductivity, ammonia, phosphates). E.g. Palustriella commutata var. commutata, Cratoneuron filicinum, Fissidens viridulus and Cinclidotus aquaticus show high preference for clear, turbulent and fast-flowing waters, with temperature below 12 °C, conductivity below 300 μS/cm, and concentrations about 0.01 mg/l for phosphates, not exceeding 0.10 mg/l for ammonium ions and 0.90 mg/l for nitrates. Leptodictyum riparium and Riccia fluitans are for their part more linked to turbid and slow waters affected by eutrophication, showing optimum values for about 0.30 mg/l for ammonia concentration, 0.90 mg/l for nitrates and 0.11 and 0.22 mg/l for phosphates respectively. Conversely, Fontinalis antipyretica is not closely related to specific conditions, showing wide ecological ranges for most of the analyzed environmental factors. This paper has evaluated and discussed the possible use of sampled species as bioindicators for biomonitoring of the water quality.  相似文献   

6.
7.
There are global calls for new ecosystem-based fisheries management (EBFM) approaches. Scientific support for EBFM includes assessing ecosystem indicators of biological communities, environmental conditions, and human activities. As part of a broader research project we have synthesized a suite of traditional and new indicators for the Grand Bank in Atlantic Canada, which we share here. This is an ideal ecosystem for indicator analysis because it experienced dramatic changes over the past three decades, including a collapse in fish biomass that had profound socio-economic consequences. We exploit the wealth of data for this ecosystem to investigate how individual indicators reflect observed changes in the ecosystem, and then illustrate two applications of this indicator suite. Correlations were used to show that relationships among the fish functional groups changed after the collapse, and that a subset of indicators is sufficient to characterize each ecosystem category. Lagged correlations highlighted how changes in the drivers and pressures are often not immediately manifest in the fish community structure. We also organized indicators into the DPSIR (driver-pressure-state-impact-response) management framework. This exercise illustrated that indicator categorization is contextual and not straightforward, and we advocate for use of simpler categories that clearly show what is actionable. Additional future analyses that can be performed with our newly published suite of indicators are recommended.  相似文献   

8.
Aim The plant diversity of one location on the Guiana Shield, Kaieteur National Park in Guyana, is used to examine the various hypothesized origins of the flora and to evaluate which may best explain the current plant distributions. Location Kaieteur National Park is located on eastern edge of the Potaro Plateau in central Guyana, South America. The species examined have distributions that vary from local to global. Methods The distribution patterns of the families, genera and species known from Kaieteur are examined using generalized distribution patterns. Results Data on distribution patterns, elevation and habitat were gathered from 131 flowering plant families, 517 genera and 1227 species. These plants represent all taxa that are currently known to occur in the area of the original Kaieteur National Park. Families tend to have cosmopolitan or pantropical distribution, genera are mostly neotropical and at the species level, most species are restricted to the Guiana Shield (c. 40%), northern South America (69%) or neotropical (96%) in distribution, each level inclusive of the previous. Conclusions The flora at the study site in Kaieteur National Park has its strongest affinity with the Guiana Shield; 42.1% of the species have a distribution that corresponds with the Shield or is more restricted within the Shield. There is a distinct flora on the Guiana Shield and its affinities lie with the flora of northern South American and beyond that, the neotropics. The flora is not closely affiliated with the floras of the Brazilian Shield, the Amazon, the Andes, the eastern coastal forests of Brazil, southern South America, or Africa as has been previous suggested.  相似文献   

9.
At least 10% of the wetlands in Mexico are situated in the State of Veracruz on the central Gulf coast. The region has been intensively used for agriculture by humans for the last thousand years and today pastureland for cattle ranching is the dominant element of the landscape. We present a study of the wetland vegetation in a series of representative and internationally significant freshwater wetlands near the coastal lagoon La Mancha in Veracruz State. We obtained eleven wetland types formed by three wetland communities dominated by trees (mangrove or swamps), eight dominated by herbaceous species which we classified as marsh, five of which were native emergent marsh, one was a non-native emergent marsh and two were floating-leaved marsh. The highest diversity values were found in the Annona swamp, followed by the Sagittaria marsh and the Rhizophora–Laguncularia–Avicennia mangrove. CCA ordination showed that water level, disturbance and species number were the major factors explaining variation along axis 1, and on axis 2 conductivity, salinity, and bulk density. Wetland size was a major factor in both axes. We examined the interplay of intrinsic and extrinsic factors that give rise to the nature and diversity of wetland types that characterize the important wetland landscapes in this part of Mexico, being disturbance by human activities an important factor that favors the appearance of diverse species combinations.  相似文献   

10.
The Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA), commonly referred to as ‘The Breaux Act’, has provided some of the resources necessary to begin implementing a comprehensive, large-scale, long-term coastal wetland restoration program for Louisiana USA. Due to the dynamic nature of this ecosystem and the uncertainty associated with large-scale restoration, adaptive management principles were embedded throughout CWPPRA’s organizational structure, planning process, project implementation, and monitoring program to facilitate achieving the mandates associated with the Breaux Act. Feedback loops were established within and between each of the programmatic components to encourage continuous learning, which is central to adaptive management. The knowledge gained has led to institutionalized change in projects as well as the program. This paper describes how the formation of the CWPPRA Task Force and associated committees and groups resulted in an integrated coast-wide process for planning, selection, construction, operation, maintenance, monitoring, and scientific evaluation of 84 restoration projects implemented or scheduled for implementation throughout coastal Louisiana.  相似文献   

11.
新疆鸟类环志与回收   总被引:2,自引:0,他引:2  
马鸣  Pau J.LEADER  Geoff J.CAREY  Barry WILLIAMS 《动物学研究》2002,23(2):105-105,106,112,135
2001年8月与14-26日在新疆阿勒泰,吐鲁番的8个环志地点进行了秋际鸟类环志工作。环志鸟类233只,约33种,多以莺亚科(Sylviinae)和鸫亚科(Turdinae)的种类为主。其中的新疆歌鸲(Luscinia sp.)等17种鸟类均属于中国首次环志种类,占环志种数的53%。  相似文献   

12.
Denny  Patrick 《Hydrobiologia》2001,458(1-3):21-31
African wetlands have important functions and values in terms of the water cycle, water quality management and biodiversity conservation. Especially relevant is their importance in food security, the provision of tradable products, and cultural and aesthetic values for local riparian communities.In Africa, knowledge of the processes, functions and values of wetlands is slim: indeed, in many regions, wetland inventories are yet to be produced. A research strategy is proposed to address some of these issues recommending an intrinsically linked, two-pronged approach: i.e. (i) studies for inventories, assessment and monitoring of wetlands and (ii) research into processes, structure and functioning of wetland ecosystems. The former has an immediate urgency whilst the latter has a long-term perspective. It is argued that curiosity-driven, (basic) research should go hand-in-hand with problem-orientated (applied) studies. Basic research is essential for a nation's scientific and technical empowerment and development. Priority topics include studies on biological diversity and integrated studies on wetlands and water resources (including water quality and the functions and values of wetland buffers).There is clear evidence of a shortage of expertise from within Africa for these topics and the reasons are discussed. Amongst others, blame is directed towards aid strategies from the industrial North and individual research programmes by `Northern' scientists in Africa. However, commitment in Africa to the actual process of scientific research is also wanting. Overall, the North have failed to stimulate a critical mass for research whilst the South suffer from a lack of momentum and from chronic under-investment.A research, training and capacity-building scheme is presented as a viable option for ameliorating the dearth of wetland resource professionals in Africa in which partnerships and networking of institutes from the North and South is encouraged.  相似文献   

13.
白洋淀湖滨湿地岸边带氨氧化古菌与氨氧化细菌的分布特性   总被引:12,自引:0,他引:12  
摘要:本研究通过分子生物学分析方法,以amoA基因为标记,考察了氨氧化古菌(Ammonia-Oxidizing Archaea, AOA)和氨氧化细菌(Ammonia-Oxidizing Bacteria,AOB)在华北平原的白洋淀这一典型湖泊的湖滨湿地岸边带系统中的生物多样性和丰度分布。在前人的研究中,氨氧化古菌在海洋、原生态土壤和人为干扰土壤等环境中主导氨氧化过程的完成。但本研究发现,在湿地岸边带系统中氨氧化过程并不是完全由氨氧化古菌主导完成,即氨氧化古菌和氨氧化细菌在不同区域分别占据主导地位。根据主导微生物的不同,可以将湿地岸边带区域划分为陆相区、中间区和湖相区。在湿地岸边带陆相区,氨氧化古菌主导氨氧化过程,氨氧化古菌的amoA基因丰度是氨氧化细菌的526倍(AOA:1.23?108每克干土;AOB:2.34?105每克干土);在岸边带湖相区,氨氧化细菌主导氨氧化过程,氨氧化古菌的amoA基因丰度只有氨氧化细菌的1/50倍(AOA:3.17?106每克干土;AOB:1.39?108每克干土);在岸边带中间区,两种微生物对氨氧化过程的贡献相当,二者的amoA基因丰度也相当 (AOA:9.83?106, AOB:4.08?106)。研究还发现,湿地中间区的微生物生物多样性高于陆相区和湖相区。在湿地中间区,氨氧化古菌和氨氧化细菌的生物多样性都最高,分别有5和7个操作分类单元(OTUs);相比之下,岸边带陆相区和湖相区的多样性依次降低,陆相区的氨氧化古菌和氨氧化细菌分别有3和6个操作分类单元,湖相区的氨氧化古菌和氨氧化细菌分别有2和6个分类单元。本研究的两个结论进一步反映了湿地岸边带极强的空间异质性。  相似文献   

14.
Abstract

Human-induced and natural stress factors can affect fine roots and ectomycorrhizas. Therefore they have potential utility as indicators of environmental change. We evaluated, through meta-analysis, the magnitude of the effects of acidic deposition, nitrogen deposition, increased ozone levels, elevated atmospheric carbon dioxide, and drought on fine roots and ectomycorrhizal (ECM) characteristics. Ectomycorrhizal colonization was an unsuitable parameter for environmental change, but fine root length and biomass could be useful. Acidic deposition had a significantly negative impact on fine roots, root length being more sensitive than root biomass. There were no significant effects of nitrogen deposition or elevated tropospheric ozone on the quantitative root parameters. Elevated CO2 had a significant positive effect. Drought had a significantly negative effect on fine root biomass. The negative effect of acidic deposition and the positive effect of elevated CO2 increased over time, indicating that effects were persistent contrary the other factors. The meta-analysis also showed that experimental conditions, including both laboratory and field experiments, were a major source of variation. In addition to quantitative changes, environmental changes affect the species composition of the ectomycorrhizal fungal community.  相似文献   

15.
The tracking of land use since 1990 presents a major challenge in greenhouse gas (GHG) reporting under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol because there is often limited availability of data, especially for the base year of 1990. There is even less land management and soil moisture data, which are needed to track climate change mitigation activities since soil moisture is one of the main drivers of GHG emissions of organic soils. Information is also needed for the reporting of land-based activities such as grazing land management or wetland drainage and rewetting of organic soils. Different spatial and thematic resolutions of land-use data produce inconsistent time series with a strong overestimation of land-use change (LUC) if not adequately accounted for. Our aim was to create a consistent time series of land use since 1990 that is in line with GHG reporting under the UNFCCC and the Kyoto Protocol by combining official cadastral data with colour-infrared aerial photography used for biodiversity monitoring in six federal states in northern and eastern Germany. We developed a generic hierarchical classification by land use, management and drainage status, and a translation key for data harmonisation into a consistent time series. This time series enabled the quantification of LUC on organic soils between 1992 and 2013 in a spatially explicit manner. Furthermore we used this time series to develop indicators for changes in land management and drainage to evaluate the success of protection statuses on peatland restoration.The study area encompassed one million hectares, half of which had some type of legal nature protection status. Areas with no protection status tended to become more intensively farmed and drier, while highly protected areas (e.g. Natura 2000) showed the opposite trend. Land-use trends also differed greatly between federal states. In Schleswig-Holstein organic soils tended to become drier during the study period, while in Mecklenburg-Western Pomerania they tended to become wetter overall. The trends and differences in LUC between federal states were linked to German reunification, changes in the European Common Agricultural Policy (CAP) and Germany's Renewable Energy Act (EEG). A large-scale peatland protection programme also had major impact.In conclusion, our study demonstrates how data derived for biodiversity monitoring and other highly detailed land-use data can be used to track changes in land use, management and drainage status in accordance with the reporting requirements under the UNFCCC and the Kyoto Protocol.  相似文献   

16.
The alcoholic beverageparakari, a unique fermentation product of cassava (Manihot esculenta Crantz) by the Wapisiana of Guyana, involves the use of a starch-hydrolyzing (amylolytic) mold (Rhizopus sp., Mucoraceae, Zygomycota) followed by a solid-state ethanol fermentation. A detailed study was made of theparakari manufacturing process in the Wapisiana village of Aishalton, South Rupununi, Guyana. Thirty steps were involved inparakari manufacture and these exhibited a high degree of sophistication, including the use of specific cassava varieties, control of culture temperature, and boosting of inoculum potential with purified starch additives. During the fermentation process, changes in glucose content, pH, taste, smell, and culture characteristics were reported for the fermenting mash.Parakari is the only known example of an indigenous New World fermentation that utilizes an amylolytic mold. Manufacture ofparakari is analogous to similar dual fermentations of the Orient, yet independently derived.  相似文献   

17.
This comparison of ethnic relations in two countries, Trinidad and Tobago, and Guyana, supplements the research findings of synchronic studies of "the social construction of race" by offering a historically based framework to understand particular and local instances of ethnic relations. Drawing on a long historical study of Trinidad and Tobago, and Guyana, I argue that the institutional sources of definition of key "ethnicities" have shifted through the centuries. "Ethnicities" have been successively defined by the institutions of capital, state and community. While these institutions have overlapped in time they are not equally important at a given moment in the matter of defining "ethnicity". The content of the definitions has also varied significantly. At present political communities and the family are the major social institutions that determine "ethnic" content.  相似文献   

18.
Fourteen species of bats are reported for the first time from Guyana (Saccopteryx gymnura, Micronycteris brachyotis, M. homezi, Lichonycteris obscura, Anoura latidens, Vampyressa pusilla, Vampyrodes caraccioli, Eptesicus chiriquinus, Cynomops paranus, Molossops neglectus, Molossus sp., Molossus coibensis, Molossus sinaloae, and Promops centralis) bringing the known bat diversity for the country to 121 species. Information including measurements, reproductive data, distribution, and taxonomy are provided for these species. Seven of these new records were collected in the Iwokrama International Rain Forest Programme site in central Guyana. Eighty-six bat species are now documented from Iwokrama Forest which is the highest species diversity for bats reported from any protected area in the world. There are, however, few tropical sites that have relatively complete inventories. A summary for bat species diversity in southern Venezuela, Guyana, Suriname, and French Guiana indicates that at least 146 species of bats are known from the Guianan subregion. Intense inventory surveys, especially in the often neglected subcanopy, suggest that species richness is probably underestimated in most Neotropical areas. Likewise, species-level diversity in the Guianan subregion is higher than previously suggested. Surveying and monitoring biodiversity are critical to developing a National Protected Areas System in Guyana.  相似文献   

19.
This paper presents the results of a study conducted at the request of the Government of Guyana by the Centre for the Study of Biological Diversity at the University of Guyana, and the Smithsonian Institution. The purpose of the study was to evaluate the utility of using systematic collections in identifying areas with a high priority for conservation. A biodiversity database and a gazetteer were assembled and interpreted primarily through the use of maps generated in ARC/INFO and ArcView. The data were examined to determine coverage and completeness, and while in general the results support a continued use of the methodology for making informed decisions in conservation related issues, several recommendations are offered in order to enhance the data. The primary use of the results of this study is in the identification of areas of interest for conservation and in the location of eleven areas covering most ecoregions in Guyana that are in need of additional study. The eleven areas have been chosen to avoid areas that are already allocated to logging and mining concessions or Amerindian lands. While it is true that this study would benefit from additional data and further analysis of those data, it is also true that decisions concerning areas for conservation in Guyana are being made in the near future, and if any data are to be used in this process, it will be those data presented in this paper.  相似文献   

20.
Sediment from 9 lakes and lagoons in 3 North African countries was analysed for a suite of organochlorine insecticides and polychlorinated biphenyls (PCBs). Residues of -HCH and pp-DDE were detected in most cores, and radiometric dating of the sediment enabled time profiles to be constructed which are indicative of recent use of the insecticide lindane and previous use of the insecticide DDT in the region. Absolute concentrations of these pesticides were relatively low compared to reported values for other world-wide locations, but exceeded recommended Canadian and Dutch environmental quality standards at several sites. Maximum fluxes of -HCH and pp-DDE (190 and 95 g m–2 yr–1, respectively) were relatively high and comparable to some sediments in North America and the United Kingdom. Other organochlorine pesticides including dieldrin were detected at low levels in some samples. Selected PCB congeners were detected at trace levels at 2 sites only, indicating low levels of industrial contamination at the sampling locations. Tropical and sub-tropical regions of the world have been suggested to be contemporary sources of globally distributed organochlorine contaminants. These data are discussed with respect to this hypothesis.  相似文献   

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