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1.
Many studies have chronicled the early development of vegetation in wetlands created as mitigation for wetland impacts; however,
very few studies have followed the floristics of wetlands that are more than 10 years post-creation. This article reports
the results of vegetation composition and structural analysis within eleven 20-yr-old created non-tidal, emergent wetlands.
Vegetation and inundation were sampled in 173 plots within 11 wetlands during the 1992 and 1994 growing seasons. A drought
occurred in 1993, thus analyses characterized vegetative response and included weighted average (weighted by the tolerance
of the species to excess soil moisture), species richness, species composition, and life history strategy. Weighted average
and species richness increased in 7 and 10 of the 11 sites, respectively. There was little change among most species including
Typha latifolia and Scirpus cyperinus, the two species with highest importance values (IV). However, among the top 10 species ranked by IV, two aquatic species
decreased and a facultative species increased. Only one of the 10 most important species, Eleocharis obtusa, was an annual and only one, Salix nigra, was a woody perennial and the IV of both species declined during the study. After 20 years, a transition from annual to
perennial graminoid life histories is suggested; however, succession from emergent to shrub–scrub or forested wetland is not
indicated. 相似文献
2.
Luca Marazzi Evelyn E. Gaiser Vivienne J. Jones Franco A. C. Tobias Anson W. Mackay 《Freshwater Biology》2017,62(2):274-290
- We explored controls of algal taxon richness (hereafter richness) in complex and hydrologically dynamic flood‐pulsed wetlands by comparing results from independent studies in two globally important subtropical wetlands: the Okavango Delta (Botswana) and the Florida Everglades (U.S.A.). In both wetlands, the flood pulse hydrology is regulated by distinct wet and dry seasons, and creates floodplain landscapes with heterogeneous habitats; algal growth is limited by phosphorus (P); and water uses threaten ecosystem function. To inform future comparisons of algal richness and distribution patterns, we assessed the role of hydrology and P as key controls of richness, and identified indicator taxa of desiccation disturbance and P scarcity in these wetlands under increasing hydrological, nutrient, and habitat changes.
- We used the intermediate disturbance hypothesis, and the species‐energy theory to explain algal richness patterns, and the competitive, stress‐tolerant, ruderal (CSR) framework to classify indicator taxa. We collected algal samples, environmental data and information expected to influence community structure (water depth, relative depth change, P concentrations, hydroperiod and habitat type) over several years at sites representing a broad range of environmental characteristics. To account for sample size differences, we estimated algal richness by determining the asymptote of taxon accumulation curves. Using multiple regression analysis, we assessed if and how water depth, depth change, P, hydroperiod, and habitat type influence richness within each wetland. We then compared the strength of the relationships between these controlling features and richness between wetlands. Using indicator species analysis on relative abundance data, we classified C, S and R indicator taxa associated with shorter/longer hydroperiod, and lower/higher P concentrations.
- In either wetland, we did not observe the negative unimodal relationship between site‐specific richness and water depth change that was expected following the intermediate disturbance hypothesis. It is possible that this relationship exists at more highly resolved temporal scales than the semi‐annual to annual scales hypothesised here. However, as nutrient flows and algal habitats depend on these wetlands' flood pulse, maintaining the Okavango's natural pulse, and increasing freshwater flow in the Everglades would help protect these wetlands' algal diversity. Chlorophyta richness (Okavango), and total, Bacillariophyta, Chlorophyta and cyanobacteria richness (Everglades) increased with higher P concentrations, as per species‐energy theory. In the Okavango, we classified 6 C and 49 R indicator taxa (e.g. many planktonic Chlorophyta), and in the Everglades, 15 C, 1 S and 9 R taxa (e.g. benthic Bacillariophyta and planktonic/benthic Chlorophyta), and one stress‐ and disturbance‐tolerant cyanobacterium species.
- Our results offer baseline information for future comparisons of richness, and abundance of C, S and R indicator taxa in subtropical wetlands; this can be used to quantify how algal communities may respond to potential changes in hydrology and P due to water diversion, anthropogenic nutrient loads, and climate change. Examining microhabitat heterogeneity, nitrogen and light availability, and grazing pressure in such wetlands would further illuminate patch‐scale controls of richness and life‐history strategy distribution in algal communities.
3.
Effects of hydrology on spatial patterns of soil development in created riparian wetlands 总被引：4，自引：0，他引：4
Surficial soil development was studied in four wetland basins created on the floodplain of the Des Plaines River near Chicago,
Illinois, USA. These studies determined changes in the spatial distribution of plant-available nutrients as a result of establishing
two different wetland hydrologic regimes. Three wetland basins had mineral soils and one an organic soil. A geostatistical
analysis including kriging of collected data indicated that all soil parameters showed significant changes in their spatial
structure as a result of the water inputs and unidirectional flows. The degree of spatial variability as indicated by autocorrelation
in the soil data (i.e., points closer to one another are more similar than points further apart due to the influence of landscape
processes) declined for all parameters except Mg+2. Temporal changes in the spatial patterns of extractable phosphorus (P) and percent organic carbon (OC) tended to be inverse;
P declined in areas where OC increased and vice versa. The spatial pattern of these changes was dissimilar in the mineral
soils as compared to the organic soil and was related to patterns of primary productivity. Zones of P uptake and OC accumulation
were also related to wetland hydrology and primary productivity. Changes in the distribution of nutrients, particularly P,
may be viewed as a result of nutrient spirals within the wetlands. By comparison, the reorganization in the concentrations
of K+ and Ca+2 appear to have been mediated by cation exchange processes. The formation of new concentration gradients was strongly related
to both flow pathways and the different water inflow rates. The formation of concentration gradients in exchangeable cations
was not reflected in the average concentrations within each basin. Mean values changed significantly in only a few instances.
Reducing data in this way missed important biogeochemical changes occurring within the experimental wetland basins.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Bia A. Almeida Esther Sebastián-González Luiz dos Anjos Andy J. Green 《Freshwater Biology》2020,65(12):2196-2210
- The restoration of degraded areas and the creation of artificial ecosystems have partially compensated for the continuing loss of natural wetlands. However, the success of these wetlands in terms of the capacity of supporting biodiversity and ecosystem functions is unclear. Research is needed to improve our understanding of the value of restored and constructed wetlands for functional diversity of freshwater fauna.
- We compared natural, restored, and artificially created wetlands present within the Doñana Natural Space, Spain and valued as important for waterbirds. We evaluated if these wetlands are equivalent in terms of waterbird functional trait diversity and composition, during both the wintering and breeding seasons. We modelled functional diversity measures and functional group species richness describing species diet, body mass, and foraging techniques with generalised linear mixed models in 20 wetlands monitored between 2006 and 2011. We used three different statistical approaches to evaluate the robustness of our results.
- Artificial wetlands constructed for conservation failed to reach the functional diversity of natural and restored wetlands. Unexpectedly, artificial ponds constructed for fish production performed better, and even exceeded natural wetlands for functional richness during winter. Fish ponds stood out as having a unique functional composition, connected with increase in richness of opportunistic gulls and decrease of species sensitive to high salinity. Overall, the functional structure of breeding communities was more affected by wetland type than wintering communities.
- Our findings suggest that compensating the loss of natural wetlands with restored and artificial wetlands results in systems with altered waterbird-supported functions, such as seed dispersal or nutrient cycling. Protection of natural Mediterranean wetlands is vital to maintain the original diversity and composition of waterbird functional traits. Furthermore, restoration must be prioritised over the creation of artificial wetlands, which, even when intended for conservation, may not provide an adequate replacement.
5.
Leah K. Swartz Winsor H. Lowe Erin L. Muths Blake R. Hossack 《Restoration Ecology》2020,28(1):206-214
Habitat loss and degradation are leading causes of biodiversity declines, therefore assessing the capacity of created mitigation wetlands to replace habitat for wildlife has become a management priority. We used single season occupancy models to compare the occurrence of larvae of four species of pond‐breeding amphibians in wetlands created for mitigation, wetlands impacted by road construction, and unimpacted reference wetlands along a highway corridor in the Greater Yellowstone Ecosystem, United States. Created wetlands were shallow and had less aquatic vegetation and surface area than impacted and reference wetlands. Occupancy of barred tiger salamander (Ambystoma mavortium) and boreal chorus frog (Pseudacris maculata) larvae was similar across wetland types, whereas boreal toads (Anaxyrus boreas) occurred more often in created wetlands than reference and impacted wetlands. However, the majority of created wetlands (>80%) dried partially or completely before amphibian metamorphosis occurred in both years of our study, resulting in heavy mortality of larvae and, we suspect, little to no recruitment. Columbia spotted frogs (Rana luteiventris), which require emergent vegetation that is not common in newly created wetlands, occurred commonly in impacted and reference wetlands but were found in only one created wetland. Our results show that shallow created wetlands with little aquatic vegetation may be attractive breeding areas for some amphibians, but may result in high mortality and little recruitment if they fail to hold water for the entire larval period. 相似文献
6.
Aims Biodiversity–ecosystem function experiments can test for causal relationships between planting diversity and community productivity. Planting diversity is routinely introduced as a design element in created wetlands, yet substantive support for the finding that early diversity positively affects ecosystem functioning is lacking for wetlands. We conducted a 2-year diversity–productivity experiment using freshwater wetland mesocosms to investigate community biomass production as affected by planted macrophyte functional richness.Methods A richness gradient of macrophytes in four emergent wetland plant functional groups was established in freshwater mesocosms for two consecutive years. Species-specific aboveground morphological traits of plant size were measured at peak growth in both years; rooting depth was measured for each species in the second year. Aboveground biomass (AGB) and belowground biomass (BGB) were harvested after peak growth in the second year; first year AGB was estimated from morphological traits in constructed regression equations. Net richness effects (i.e. both complementarity effects and selection effects) were calculated using an additive partitioning method.Important findings Species richness had a positive effect on community AGB relative to monocultures in the first year. In the second year, mean AGB was significantly reduced by competition in the most species-rich mixtures and all mixtures underyielded relative to the average monoculture. Competition for soil resources was weaker belowground, whereby root distribution at depths>20cm was reduced at the highest richness levels but overall BGB production was not affected. Changes in species biomass were strongly reflected by variation in species morphological traits, and species above and belowground performances were highly correlated. The obligate annual (Eleocharis obtusa), a dominant competitor, significantly contributed to the depression of perennial species' growth in the second growing season. To foster primary productivity with macrophyte richness in early successional communities of created wetlands where ruderal strategies are favored and competition may be stronger than species complementarity, unsystematic planting designs such as clustering the same or similar species could provide protection for some individuals. Additionally, engineering design elements fostering spatial or temporal environmental variability (e.g. microtopography) in newly created wetlands helps diversify the responses of wetland macrophyte species to their environment and could allow for greater complementarity in biomass production. 相似文献
7.
Most megadiversity regions lack basic wild animal diversity information such as species lists. This absence of basic knowledge restricts the development and effectiveness of conservation action plans, which are urgently needed for animal groups such as amphibians, the most threatened vertebrate group in the world. In this study, we estimated Brazilian anuran diversity based on species range distribution shapes and evaluated factors that likely affect species lists, such as current taxonomy knowledge, current number of specimens collected in each region, biome characteristics, and anuran size (snout–vent length). We were able to demonstrate differences among the distributional patterns of species within each biome and each Brazilian federative state and among certain factors that influence their diversity, such as latitudinal variation. In this integrative study, we provide zoogeographic information about the richest (in terms of anuran biodiversity) country in the world (at least 849 described species, about 60% of which are endemic), which may be fundamental to future conservation actions in Brazil. 相似文献
8.
截止2020年1月31日,贵州省共记录两栖动物2目11科30属97种,其中贵州省特有种20种。与《贵州两栖动物志》（1986）相比,共增加了35种。本文基于近40年来两栖动物分类学和系统学的相关研究成果,整理并修订贵州省两栖动物物种与分布名录。更正了38种两栖类的名称,删除1种。对贵州的两栖动物新分布区进行了总结和区系组成分析,结果表明,贵州省的两栖动物以西南区种和华中华南区种为主,华中华南及西南区种和华中区种次之,华南区种最少,另有外来入侵种1种。根据中国脊椎动物红色名录,共有3种极危、6种濒危、21种易危、12种近危、36种无危和5种数据缺乏。 相似文献
9.
This study explores the relationship between microtopography and soil nutrients (and trace elements), comparing results for created and reference wetlands in Virginia, and examining the effects of disking during wetland creation. Replicate multiscale tangentially conjoined circular transects were used to quantify microtopography both in terms of elevation and by two microtopographic indices. Corresponding soil samples were analyzed for moisture content, total C and N, KCl-extractable NH4 –N and NO3 –N, and Mehlich-3 extractable P, Ca, Mg, K, Al, Fe, and Mn. Means and variances of soil nutrient/element concentrations were compared between created and natural wetlands and between disked and nondisked created wetlands. Natural sites had higher and more variable soil moisture, higher extractable P and Fe, lower Mn than created wetlands, and comparatively high variability in nutrient concentrations. Disked sites had higher soil moisture, NH4 –N, Fe, and Mn than did nondisked sites. Consistently low variances (Levene test for inequality) suggested that nondisked sites had minimal nutrient heterogeneity. Across sites, low P availability was inferred by the molar ratio (Mehlich-3 [P/(Al + Fe)] < 0.06); strong intercorrelations among total C, total N, and extractable Fe, Al, and P suggested that humic–metal–P complexes may be important for P retention and availability. Correlations between nutrient/element concentrations and microtopographic indices suggested increased Mn and decreased K and Al availability with increased surface roughness. Disking appears to enhance water and nutrient retention, as well as nutrient heterogeneity otherwise absent from created wetlands, thus potentially promoting ecosystem development. 相似文献
10.
2009～2010年对北京松山国家级自然保护区两栖爬行类进行了4次调查,调查到两栖爬行类11种,隶属于2目7科。古北界10种,东洋界1种。对比1991年的调查结果,此次调查未发现丽斑麻蜥、赤链蛇、红点锦蛇、团花锦蛇、双斑锦蛇、虎斑颈槽蛇6种爬行类。草地生境两栖爬行类物种多样性最高。中国林蛙(主要分布于溪流)和山地麻蜥(主要分布于岩壁)分别是种群数量最多的两栖类和爬行类物种。在保护实践中可优先保护两栖爬行类物种多样性较高的关键区域,以提高保护成效。 相似文献
11.
12.
Influence of physical processes on the design, functioning and evolution of restored tidal wetlands in California (USA) 总被引：1，自引：0，他引：1
J. Haltiner J. B. Zedler K. E. Boyer G. D. Williams J. C. Callaway 《Wetlands Ecology and Management》1997,4(2):73-91
The performance of two intertidal wetland mitigation projects constructed by the California Department of Transportation (Caltrans) in the Sweetwater Marsh National Wildlife Refuge (SMNWR) in San Diego Bay was evaluated over 5 years. Most of the Sweetwater wetland complex has been altered this century, including diking (with subsequent subsidence), filling, modification of the tidal regime, freshwater inflow and sediment fluxes. The mitigation project goals included a range of functional criteria intended to support two endangered bird species (light-footed clapper rail and California least tern) and one endangered plant (salt marsh bird's-beak). While the mitigation projects have achieved some of the performance criteria established in the regulatory permits (particularly, those related to fish), vegetation criteria for one of the bird species have not been met. The initial grading (in relation to local tidal datums) should support the target plant species, but growth has been less than required. Shortcomings of the habitat include elevated soil and groundwater salinity, low nutrient levels (especially nitrogen, which is readily leached from the coarse substrate), and eroding topography (where a single oversized and overly sinous channel and the lower-than-natural marshpalin result in high velocity surface water flow and erosion). The failure to achieve a large plain at low-marsh elevations highlights the importance of a more complete understanding of the relationship between the site physical processes (topography, hydrology, climate, geomorphology), substrate conditions, and biotic responses.Corresponding editor: R.E. Turner 相似文献
13.
深圳湾湿地两栖爬行动物及其保护 总被引：6，自引：0，他引：6
深圳湾湿地共有两栖动物８种,隶属于１目４科,有爬行动物２３种,隶属于３目（亚目）２０科．分析了深圳湾湿地两栖爬行动物的区系特点、种群数量变化和现状,在此基础上提出了保护两栖爬行动物的建议和对策． 相似文献
14.
Armand M. Kuris 《Hydrobiologia》1993,265(1-3):1-14
The Netherlands occupy 41,864 km2 of which about 6,600 km2 (16%) have been classified as internationally important wetlands. About 3000 km2 (7%) have been included in the Ramsar Convention list of internationally important wetlands.
The situation of the wetlands in The Netherlands has seen large changes during the last 2000 years. Thousands of km2 of peatlands have disappeared; thousands of km2 of coastal salt marshes and a similar area of shallow lakes have been reclaimed for agriculture.
The Dutch wetlands occupy a key position in the bird migration of the West-Palaearctic flyway.
The hydrology of The Netherlands and of Dutch wetlands is dominated by the river Rhine. Hence, nutrients and contaminants
imported by the Rhine and from other sources have a major impact on Dutch wetlands. Reduction of pollution and eutrophication
is a major requirement for conservation of Dutch wetlands. Dutch politics appears to be moving in this direction. 相似文献
15.
Recovery of physical conditions and processes is increasingly emphasized in ecosystem restoration. We examined a restoration project aimed at recovery of groundwater levels and base flows on an undammed desert river. We sampled streamside plant communities and hydrology annually (2003–2008) at six restoration sites at two farms (Three Links Farm and H&E Farm) after groundwater pumping was curtailed for restoration purposes, and at six reference sites. Vascular plant cover was recorded, and species were classified into functional groups based on water needs and life history. Synthetic vegetation metrics and community composition were compared between restoration sites and perennial‐flow reference sites representing target conditions. Perennial sites had higher cover, species richness, relative cover of hydric perennials and hydric annuals, and lower wetland indicator scores than non‐perennial sites, but did not differ in relative cover of non‐native species. Perennial sites had distinct species composition and high species constancy among years. Streamside vegetation was similar at Three Links Farm and perennial reference sites, indicating restoration success; streamside vegetation at H&E Farm differed from target conditions according to most measures. Hydrology is a key factor shaping desert streamside plant communities. However, single river sites may respond differently to hydrologic restoration. Contrasts in site response were likely due to differences in hydrogeomorphic context, exacerbated by drought. Understanding the constraints on restoration response is critical for setting realistic restoration goals and anticipating time frames of ecosystem change. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
16.
- As anthropogenic activities continue to impact ecosystems around the world, the ability to monitor and manage ecosystem health and function increases in importance. Despite this need for monitoring, management projects are often limited by the funding, time and personnel required to gather field data. These costs only increase when considering large dynamic ecosystems, such as pulsed wetlands, that have spatially and temporally variable habitat conditions, thus requiring frequent field measurements across the landscape.
- The ability to use sensory data can drastically reduce the resources required to monitor field conditions, but can limit the scope and resolution at which data can be measured. Using the Florida Everglades as a model system because of its extensive monitoring and instrumentation network, we compared the effectiveness of large‐scale sensory models of hydrological data with models that incorporate additional fine‐scale habitat variables to account for variations in the dry season densities of small fishes and macroinvertebrates.
- Since the magnitude of aquatic faunal densities during the dry season greatly affect higher trophic groups, such as wading birds and alligators, the ability to understand the drivers on fish and crayfish densities is of high importance for Everglades restoration and management plans.
- We found that models using only sensory hydrological variables supported the same hypotheses as models that incorporated additional habitat variables, but the degree of fit was reduced considerably and varied depending on species group. Species more heavily dependent on water for reproduction and survival, such as fish, tended to have better fitting models than species less dependent on water, such as crayfish. Additionally, sensory‐only models were able to detect different responses between size classes of fish to the processes that drive their concentration into drying pools of water, with large fish (>2.5 cm) densities influenced more by landscape structure and small fish (<2.5 cm) densities influenced more by hydroperiod.
- Our results support the use of sensory data to identify important variables affecting populations for management and restoration efforts. However, the degree to which sensory variables are able to fit species data is dependent upon the ability of sensors to measure major ecosystem drivers and the scale at which sensors can measure environmental change. Although tradeoffs exist between coarse sensory data and finer site‐specific measurements, the benefits of sensory data will increase as the scale of ecosystem management and restoration increases.
17.
《Ecohydrology》2017,10(7)
Forested wetlands dominated by black ash (Fraxinus nigra ) are currently threatened by the rapid expansion of the exotic emerald ash borer (EAB; Agrilus planipennis , Coleoptera: Buprestidae) in North America, and very little is known about the hydrology and ecology of black ash wetlands. The ecohydrological response of forested wetlands following a canopy disturbance has the potential to affect critical ecosystem services, and the degree of this effect may largely depend on the wetland's hydrogeological setting. The main objectives of this study were to characterize the hydrologic connectivity of uninfested black ash wetlands and evaluate the water table response to a simulated EAB disturbance. We hypothesized that black ash wetlands in northern Michigan were (a) seasonally connected to, and derived the majority of their water from groundwater, and (b) wetland water tables would be elevated following a simulated EAB infestation due to decreased transpiration with the loss of black ash. The results indicate that the black ash wetland sites received most of their water from groundwater discharge. Significantly smaller site transpiration fluxes and significantly slower rates of drawdown were detected during the growing season in the girdled and ash‐cut treatment sites, and these responses collectively produced significantly elevated wetland water tables when compared to control sites in the latter portions of the growing season. However, the wetlands' strong connection with groundwater sources likely buffered the magnitude of hydrological responses associated with the loss of black ash from the landscape. 相似文献
18.
克隆植物生长型的研究进展 总被引：17，自引：3，他引：17
克隆植物生长型的研究进展陈尚李自珍王刚（国家海洋局第一海洋研究所,青岛２６６００３）（兰州大学,７３００００）ＡｄｖａｎｃｅｓｉｎＲｅｓｅａｒｃｈｅｓｏｆＧｒｏｗｔｈＦｏｒｍｏｆｔｈｅＣｌｏｎａｌＰｌａｎｔ．ＣｈｅｎＳｈａｎｇ（ＦｉｒｓｔＩｎｓｔｉｔ... 相似文献
19.
安徽省两栖爬行动物名录修订 总被引：1，自引：0，他引：1
参考两栖爬行动物分类学和分子系统学的最新研究成果, 收集了近年来安徽省两栖爬行类相关的研究资料, 整理成安徽省两栖爬行类物种与分布名录。截止到2018年11月30日, 安徽省共记录两栖动物2目9科26属44种, 其中安徽特有种3种; 爬行动物3目11科48属72种, 其中安徽特有种1种。与《安徽两栖爬行动物志》(1991)相比, 共增加了12种, 删除1个物种, 更改了29个物种的名称。区系分析表明, 东洋界种类91种(78.4%), 古北界种类10种(8.7%), 广布型15种(12.9%)。列入《国家重点保护野生动物名录》的有4种, 列入《中国脊椎动物红色名录》的有112种。 相似文献
20.
Phragmites australis (common reed) has expanded in many wetland habitats. Its ability to exclude other plant species has led to both control and eradication programs. This study examined two control methods—herbicide application or a herbicide‐burning combination—for their efficacy and ability to restore plant biodiversity in non‐tidal wetlands. Two Phragmites‐dominated sites received the herbicide glyphosate. One of these sites was burned following herbicide application. Plant and soil macroinvertebrate abundance and diversity were evaluated pre‐treatment and every year for four years post‐treatment using belt transects. The growth of Phragmites propagules—seeds, rhizomes, and rooted shoots—was examined in the greenhouse and under bare, burned, or vegetated soil conditions. Both control programs greatly reduced Phragmites abundance and increased plant biodiversity. Plant re‐growth was quicker on the herbicide‐burn site, with presumably a more rapid return to wetland function. Re‐growth at both sites depended upon a pre‐existing, diverse soil seed bank. There were no directed changes in soil macroinvertebrate abundance or diversity and they appeared unaffected by changes in the plant community. Phragmites seeds survived only on bare soils, while buried rhizomes survived under all soil conditions. This suggests natural seeding of disturbed soils and inadvertent human planting of rhizomes as likely avenues for Phragmites colonization. Herbicide control, with or without burning, can reduce Phragmites abundance and increase plant biodiversity temporarily. These changes do not necessarily lead to a more diverse animal community. Moreover, unless Phragmites is eradicated and further human disturbance is prohibited, it will likely eventually re‐establish dominance. 相似文献