辽河三角洲湿地的景观破碎化分析

利用遥感、ＧＩＳ手段对辽河三角洲的湿地景观进行研究,并选用６种不同的方法对研究区的景观破碎化程度进行分析．结果表明,研究区的景观破碎化程度较低,总体斑块密度为０．２８６个·ｋｍ－２,廊道密度为１．０９８ｋｍ·ｋｍ－２,聚集度指数为０．９５５．景观破碎化与人类活动密切相关,随着人类活动的增加,景观破碎化程度加深．廊道景观的发展是景观破碎化的前提与动因．     

Evaluation of Florida Palustrine Wetlands: Application of USEPA Levels 1, 2, and 3 Assessment Methods

Three categories of wetland assessment methods have been recognized by the United States Environmental Protection Agency, including Level 1—Landscape-scale Assessment; Level 2—Rapid Field Methods; and Level 3—Intensive Biological and Physico–Chemical Measures. This study incorporates wetland assessment methods for each assessment level, including the Level 1 Landscape Development Intensity (LDI) index, Level 2 Wetland Rapid Assessment Procedure (WRAP), and Level 3 Florida Wetland Condition Index (FWCI). Using a neighborhood analysis in Geographic Information Systems (GIS), an LDI index map was created using 1995 land use, creating a calculated LDI index value for each 30 m² area in Florida. Level 1–3 assessment procedures were employed at 193 palustrine emergent (n = 75) and forested (n = 118) wetlands. Significant correlations were found among the multiple Level 1–3 assessment procedures using the nonparametric Spearman’s correlation coefficient for pair-wise comparisons of LDI and WRAP, LDI and diatom FWCI, WRAP and diatom FWCI, LDI and macrophyte FWCI, WRAP and macrophyte FWCI, LDI and macroinvertebrate FWCI, and WRAP and macroinvertebrate FWCI (|r| > 0.50, P < 0.01). Defining the relationship between Level 1–3 assessment methods may be used to estimate the more intensive and species assemblage-specific Level 3 FWCI assessment scores for wetlands with Level 1 or Level 2 scores. Inferences can then be made as to wetland condition based on established correlations with intensive assessment methods.     

Landscape patterns and their changes in Sichuan Ruoergai Wetland National Nature Reserve

In Sichuan Ruoergai Wetland National Nature Reserve, the changes in landscape patterns over a period of 17 years – from 1990 to 2007 – have been studied by means of RS, GIS technologies and field validation. In the reserve, the seven landscape patterns – river, lake, swamp, seasonal swamp, meadow, shrub and desert – were subject to the current study. The results show that the swamp, seasonal swamp, and meadow are the dominant landscape types occupying over 90% of the reserve’s total area. Over the past 17 years, the distribution area of swamp has been decreased by 3.81%, while that of seasonal swamp and meadow has been increased by 2.58% and 2.09%, respectively. In addition, the desert area has expanded by 1.19% since 2000. The nature reserve can be characterized by patch diversity, causing landscape fragmentation over the years; the total number of patches increased to 585 from 544 and the average area of the patches decreased to 283.49 h m² from 304.29 h m² – to the detriment of the wetland functions such as carbon sink and habitats for wild animals. In the study, the causes of the alternations are discussed as mainly resulting from climate change and human disturbances such as overgrazing, drainage, and unmanaged tourism. The study results provide a scientific basis at a strategic scale for the efficient conservation and management implementation of nature reserve zoning and assessment of landscape ecological functions and conservation values.     

Relationship between landscape structure metrics and wetland nutrient retention function: A case study of Liaohe Delta, China

The relationship between landscape pattern and the function of nutrient reduction in the natural reed marsh of Liaohe Delta is studied with the help of some landscape metrics. The results discovered that not all the metrics selected are explanative in representing the function of nutrient reduction. Network connectivity, area size, and source to centre metrics are closely related to the simulation results from different pattern scenarios, while other metrics like area-weighted mean shape, fractal, contagion and aggregation are not related with the reduction process at all. Different metrics should be chosen according to the purpose of the study, based on the criteria of simplicity, generality and ecological meaning.     

东方白鹳幼鸟在繁殖区生境选择的跟踪研究

鸟类的生境选择与气候、栖息地及人为干扰有关,而在不同生活史阶段因其自身需求及环境资源的变化也将出现差异。为明晰该一过程和规律,基于东方白鹳(Ciconia boyciana)在三江平原的卫星跟踪数据,按照时间序列通过核密度分析法(95%水平)得到繁殖季节(7—10月)跟踪个体的活动范围变化,据此将该时期细分为在巢期与离巢游荡期两个阶段,在巢期活动范围窄且高度聚集于单一区域,而离巢游荡期活动范围分散于三江平原东部和北部的多个地点。后采用Maxent模型对两个阶段的适宜生境空间分布及其主要因子进行评估发现,在巢期和离巢期主要影响因子分别为(在巢期贡献率/离巢期贡献率):土地覆被类型(11.8%/30.6%)、水体(23.8%/31.2%)、相对湿度(8.1%/15.5%)、草本沼泽(28.6%/3.2%)及相对风速(13.2%/2.1%);离巢期的较适宜生境(0.4—1)比在巢期扩大近两倍,且对人为活动表现出更强的耐受性。本研究结果可用于东方白鹳及其他迁徙鸟类繁殖相关的动态保护与有效综合管理。     

江南丘陵稻田湿地景观生态系统功能与效益研究──以攸县为例

在对江南丘陵典型区域──湖南省攸县的稻田湿地进行分类的基础上,分析了稻田湿地的空间格局和功能,并采用ＡＨＰ法对其综合效益进行了评价．结果表明,攸县稻田湿地可分为淹育性、渗育性、潴育性和潜育性稻田湿地４种类型,其空间优势度分别为４．１７、２６．４、１２．３２和３１．２５．稻田湿地的能量产投比为４．６８,Ｎ、Ｐ、Ｋ的产投比分别为０．５９、１．５９和１．２３,其综合效益为０．６６．     

中国河口湿地研究现状及展望

河口湿地由于其发育和形成过程较为特殊,加上其丰富的动植物资源以及重要的经济地位,已成为我国湿地研究领域的一个新热点.本文在分析中国河口湿地分布与特征的基础上,从河口湿地生物多样性、河口湿地生态过程及动态变化、河口湿地的形成和发育机制、河口湿地景观格局及动态演变、河口湿地恢复与重建、河口湿地的人地关系、河口湿地与全球变化、河口湿地评价以及数字河口湿地建设等方面总结了我国河口湿地研究现状.尽管中国河口湿地研究的方向和成果已经比较丰富,但与国外相比,在技术和理念上还存在一定差距.结合国外河口湿地研究的最新动态,提出了中国河口湿地未来研究的4个重要方向：河口湿地的人地关系、河口湿地的恢复和重建、河口湿地与全球变化以及河口湿地综合信息系统建设.     

Comparison of land use/land cover change and landscape patterns in Honghe National Nature Reserve and the surrounding Jiansanjiang Region,China

Land use and land cover change (LUCC) determines landscape patterns and affects the ability of ecosystems to provide the services and biodiversity on which humans ultimately depend. The Honghe National Nature Reserve is a biodiversity-rich area in the Jiansanjiang region of northeast China. In this study, the LUCC and landscape patterns were compared between the reserve and the Jiansanjiang region. With remote sensing (RS) and geographic information system (GIS) procedures, satellite images from 1989, 2001 and 2010 were used to calculate dynamics of LUCC amplitudes, landscape pattern index, transition matrix. The influence of LUCC on the wetland landscape of the nature reserve was discussed in the context of broader LUCC analyses. The results showed that land uses in the studied regions changed remarkedly over the time period; swamp area declined significantly as arable land increased. The ecological landscape index showed that distinct landscape patches were small, scattered and highly fragmented, moving toward a more monotonous landscape. Anthropogenic activities such as farming directly decreased the wetland landscape diversity. Furthermore, anthropogenic factors diminished wetland areas indirectly through climatic factors, namely air temperature and precipitation levels. National and regional policies on agriculture and water use have been highly influential, and the Honghe National Nature Reserve is highly susceptible to land use changes in the surrounding Jiansanjiang region.     

Comparing disturbance gradients and bird-based indices of biotic integrity for ranking the ecological integrity of Great Lakes coastal wetlands

We compared different methods for generating indices of biotic integrity (IBIs) for Great Lakes coastal wetlands using bird community data collected by participants in Bird Studies Canada's Great Lakes Marsh Monitoring Program (GLMMP) including: rank sum and multivariate approaches for defining landscape disturbance gradients; and generalist-specialist (IBI-1), multimetric (IBI-2), and probabilistic (IBI-3) approaches for calculating IBIs. Scores from the multivariate disturbance gradient, IBI-1, and IBI-3 increased rapidly at the impaired and unimpaired ends of the impaired-to-unimpaired spectrum, whereas scores from the rank sum disturbance gradient and IBI-2 increased rapidly only at the unimpaired end. IBIs with metrics that both increased and decreased along the landscape disturbance gradient were more sensitive for identifying especially impaired and unimpaired sites (i.e., IBI-1 and IBI-3) compared to IBIs with metrics that only increased (i.e., IBI-2). Scores from all but one of the IBIs were significantly correlated with scores of at least one of the landscape disturbance gradients and scores from all three of the IBIs were significantly moderately correlated with each other (r_s = 0.3–0.7). Site ranks arranged from impaired to unimpaired differed by 25–50 positions out of 142 possible positions depending on the pair of IBIs chosen. Much of the variation that we observed could be explained by differences among IBIs in the metrics that contributed most to impaired and unimpaired sites. Thus, we recommend the following not only for IBI users assessing the integrity of Great Lakes coastal wetlands, but also any other ecosystem where multiple landscape disturbance gradients and IBIs are available for use: (1) use multivariate instead of rank sum approaches for defining landscape disturbance gradients; (2) use IBIs with metrics that both increase and decrease along the landscape disturbance gradient instead of IBIs with metrics that only increase or only decrease; and (3) ensure that site-level species lists are reasonably complete, particularly for species that disproportionately contribute to especially impaired and unimpaired scores. Following these guidelines will increase the sensitivity and accuracy of IBIs for identifying especially impaired and unimpaired sites and ultimately result in better conservation.     

Constructing multimetric indices and testing ability of landscape metrics to assess condition of freshwater wetlands in the Northeastern US

Using data collected for the Environmental Protection Agency's (EPA) 2011 National Wetland Condition Assessment (NWCA), we developed separate multimetric indices (MMIs) for vegetation, soil, algae taxa, and water to assess condition of freshwater wetlands in the northeastern US. This study represents the first attempt at developing multiple biotic and abiotic MMIs of wetland condition over this large of an area, and is only possible because of the high quality data collected by the NWCA. We chose metrics that distinguished between reference and most disturbed sites, had a signal:noise ratio > 2, and were not strongly correlated with other metrics, latitude, or longitude. The vegetation and soil MMIs were the best performing indices, with good separation between reference and most disturbed sites, and included commonly used condition metrics (e.g., pH and P concentration for soil, and percent cover of exotic species for vegetation). The algae MMI was the weakest index, with considerable overlap between reference and most disturbed sites. For areas smaller than our study, algae taxa may be suitable for wetland MMIs. However, in our study area, many algae taxa followed strong latitudinal or longitudinal gradients, and could not be considered for the algae MMI. Small sample size and several metrics with a high signal:noise ratio were the major limitations of the water MMI. We also examined how well landscape (level 1) and rapid assessment (level 2) metrics predicted MMIs using random forest regression. Agricultural land use surrounding wetlands was an important predictor for all four MMIs, although the soil, algae and water MMI models performed best when intensive (level 3) vegetation metrics were also included in the random forest regression models. Based on these results, we recommend wetland assessment programs employ a combination of landscape and rapid assessment monitoring at many sites, along with level 3 monitoring at a subset of sites. We developed these MMIs to evaluate freshwater wetland condition for a long-term monitoring program in Acadia National Park. These MMIs are also applicable to a range of wetland types covering 11 states in the northeastern United States and can be calculated using a downloadable spreadsheet that calculates and rates each MMI using raw metric values.     

The ecological condition of geographically isolated wetlands in the southeastern United States: The relationship between landscape level assessments and macrophyte assemblages

Geographically isolated wetlands (GIWs) are common features of the Dougherty Plain physiographic region in southwestern Georgia. Due to lack of protection at the state and federal levels, these wetlands are threatened by intensive agricultural and silvicultural land uses common in the region. Recently, the ecological condition of such GIWs was assessed for the southeastern United States using the Landscape Development Intensity Index (LDI), a practical assessment tool that relies on remotely sensed land use and land cover (LULC) data surrounding isolated wetlands to rapidly predict wetland condition. However, no assessments have been attempted for GIWs in the Dougherty Plain specifically. Our goal was to develop a framework to guide and refine remote assessment of wetland condition within this agriculturally intense region of the southeastern USA. In this study, we characterized human disturbances associated with isolated wetlands in the Dougherty Plain, and paired the rapid assessment of GIWs using LDI with an intensive assessment of wetland plant communities. Specifically, we: (1) examined how macrophyte assemblages and vegetation metrics vary across a human disturbance gradient in the Dougherty Plain; (2) compared multiple condition assessment outcomes using variations of the LDI method that differed in spatial extent and resolution of LULC categories; and (3) determined the predicted condition of GIWs in the Dougherty Plain as indexed by LDI and compared with region-wide assessments of GIWs of the southeastern USA. Generally, the relationship between wetland plant communities and surrounding land use supported the assumptions of the LDI index in that wetlands surrounded by agricultural land use classes featured distinct plant communities relative to those surrounded by forested land use classes. Our results indicated that finer spatial resolution of LULC data improved the predictive ability of LDI. However, based on incongruence between wetland vegetation composition and LDI scores in some forested landscapes, this study identified limitations of the LDI assessment method, particularly when applied in regions in which prescribed fire is an important ecological driver of vegetation and habitat. Thus, we conclude that LDI may be biased toward an overestimation of reference condition GIWs, even though the habitat may be functionally degraded by the absence of natural processes such as fire. Regardless, relative to the assessment of the entire southeastern US, a greater proportion of total GIWs of the Dougherty Plain were identified as impaired due to the intensity of irrigated agricultural land use.     

湿地退化的经济成因分析

运用环境经济学中的外部性与产权等理论,结合天然湿地的一些经济属性,对湿地退化的经济学原因进行探讨与分析,以期为湿地保护提供理论基础。湿地的“椎公共资源性”决定了在湿地资源的使用过程中不能排除他人使用这种财产的权利,以至造成对湿地的抢先使用和过度开发：从外部性理论的角度分析,湿地保护的正外部性行为未得到应有补偿,湿地破坏的负外部性行为未付出应有代价,缺乏正反两种外部性的补偿与制约是造成湿地退化的主要原因之一：湿地资源的特点决定其产权不完整,湿地保护者无法完整拥有湿地带来的所有收益或无法控制湿地收益的稳定,故而对湿地保护不足;湿地资源具有稀缺性,但由于其许多效益缺乏市场或湿地资源价格偏低,使得市场无法真实反映湿地资源的价值,造成湿地资源退化或丧失。     

Classification and inventory of wetlands: A global overview

Classification of wetlands is extremely problematical, definition of the term wetland being a difficult and controversial starting point. Although considerable effort has gone into the development of national and regional wetland classifications, the only attempt at establishing a global system has been under the auspices of the Ramsar Convention on Wetlands of International Importance. In view of the fact that the Ramsar Convention has 70 Contracting Parties world-wide, it is suggested that the Convention's definition and classification system should be adopted generally for international purposes. Much of the world has been covered by preliminary wetland inventories, but there is an urgent need to extend coverage to those areas not yet included. It is essential that all inventory projects give adequate attention to meeting the real information needs of agencies and individuals which have an impact on the conservation and wise use of wetlands. Attention should also be given to providing for wide dissemination and regular updating of information and establishment of procedures for monitoring ecological change at the sites identified.     

Marsh wetland degradation risk assessment and change analysis: A case study in the Zoige Plateau,China

Wetlands play an important role in regional development and environmental protection. Under the impact of natural and artificial factors, the plateau wetlands have degenerated and even disappeared, resulting in serious problems for society and the ecological environment. It is necessary to establish a reasonable risk assessment method to evaluate the risk of wetland degradation, and then to analyze changes in the range and features of risk. For this work, the Zogie Plateau wetland was selected as the study area. For this site, a wetland degradation risk assessment method was established based on the conceptual model of Ecological Risk Assessment (ERA). The method included nine indicators used to analyze the wetland hazard index, wetland vulnerability index, and wetland degradation risk synthetically. From the spatial-temporal pattern, the wetland degradation risk was analyzed using data from 2000 to 2014. The calculated results revealed the following: (1) from 2000 to 2014, the wetland hazard index (WHI) showed a trend of increase, the value of which increased from 0.29 to 0.42, with a growth rate of 44.83%. Similarly, the wetland vulnerability index (WVI) significantly increased from 0.30 to 0.54, with a growth rate of 80%. Over the same time, the total wetland area decreased from 3910.25 km² to 2777.38 km², a reduction of 28.97%. (2) Using the equidistant method, the risk value was divided into three risk grades. The wetland degradation risk in the whole region is increasing, and the risk rank has changed from the low risk zone (0.092) to the medium risk zone (0.25). The degradation risk becomes greater with distance from the center to fringe areas.     

景观规划：概念、起源与发展

对目前地理学、景观生态学等领域中所存在的关于景观概念的多种不同解释进行了分析和总结,并将景观与土地、环境和风景等经常引起混乱的概念术语也做了分析对比．在此基础上,讨论了景观规划的概念内涵和它所基于的景观概念,并通过对景观规划的起源与发展过程的总结和分析,将景观规划的起源与发展归纳为３个阶段：１９世纪中后期到２０世纪初期的的起源阶段;５０、６０年代景观规划领域的形成阶段和７０年代以后的景观规划与景观生态学融合发展阶段     

Creating riverine wetlands: Ecological succession, nutrient retention, and pulsing effects

Successional patterns, water quality changes, and effects of hydrologic pulsing are documented for a whole-ecosystem experiment involving two created wetlands that have been subjected to continuous inflow of pumped river water for more than 10 years. At the beginning of the growing season in the first year of the experiment (1994), 2400 individuals representing 13 macrophyte species were introduced to one of the wetland basins. The other basin was an unplanted control. Patterns of succession are illustrated by macrophyte community diversity and net aboveground primary productivity, soil development, water quality changes, and nutrient retention for the two basins. The planted wetland continued to be more diverse in plant cover 10 years after planting and the unplanted wetland appeared to be more productive but more susceptible to stress. Soil color and organic content continued to change after wetland creation and wetlands had robust features of hydric soils within a few years of flooding. Organic matter content in surface soils in the wetlands increased by approximately 1% per 3-year period. Plant diversity and species differences led to some differences in the basins in macrophyte productivity, carbon sequestration, water quality changes and nutrient retention. The wetlands continued to retain nitrate–nitrogen and soluble reactive phosphorus 10 years after their creation. There are some signs that sediment and total phosphorus retention are diminishing after 10 years of river flow. Preliminary results from the beginnings of a flood pulsing experiment in the two basins in 2003–2004 are described for water quality, nutrient retention, aboveground productivity, and methane and nitrous oxide gaseous fluxes.     

Mitigation under Section 404 of the Clean Water Act: where it comes from, what it means

The requirement to mitigate impacts to wetlands and streams is a frequently misunderstood policy with a long and complicated history. We narrate the history of mitigation since the inception of the Clean Water Act Section 404 permit program in 1972, through struggles between the US Environmental Protection Agency and the US Army Corps of Engineers, through the emerging importance of wetland conservation on the American political landscape, and through the rise of market-based approaches to environmental policy. Mitigation, as it is understood today, was not initially foreseen as a component of the Section 404 permitting program, but was adapted from 1978 regulations issued by the Council on Environmental Quality as a way of replacing the functions of filled wetlands where permit denials were unlikely. EPA and the Corps agreed in 1990 to define mitigation as the three steps of avoidance, minimization, and compensation, principles which must be applied to permit decisions in the form of the environmental criteria in EPA’s 404(b)(1) Guidelines. Through the 1980s and 1990s, the compensation component of mitigation has become nearly the sole focus of mitigation policy development, and has been the subject of numerous guidance documents and memoranda since 1990. Avoidance and minimization have received far less policy attention, and this lack of policy development may represent a missed opportunity to implement effective wetland conservation.

景观指数分类、应用及构建研究

在景观生态学研究中,理解与把握景观格局变化的生态学原则至关重要,用景观指数描述景观格局及变化,建立格局与景观过程之间的联系,是景观生态学最常用的定量化研究方法,本文在综合前人对景观指数的基础上,对景观指数研究从景观指数的分类研究,指数对景观格局的描述研究,指数之间的相关性研究及指数构建研究等4方面进行了总结,并从单个景观指数与指数体系两个层次上提出了判定景观指数优劣及景观指数应用的一般性原则。