首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The use of multiple stable isotopes in the study of trophic relationships in temperate estuaries has usually been limited to euhaline systems, in which phytoplankton, benthic microalgae, andSpartina alterniflora are major sources of organic matter for consumers. Within large estuaries such as Chesapeake Bay, however, many species of consumers are found in the upper mesohaline to oligohaline portions. These lower salinity wetlands have a greater abundance of macrophytes that use C3 photosynthesis to fix carbon, in addition toS. alterniflora, which fixes carbon via the C4 photosynthetic pathway. In a broad survey of the biota and sediments of a brackish tidal creek tributary to Chesapeake Bay, combined δ13C and δ34S measurements disclosed a balanced contribution to secondary production from phytoplankton, C3 macrophytes,Spartina sp., and benthic microalgae. Surface sediment δ13C suggested that the organic matter from C3 plants was derived both from allochthonous sources (terrestrial runoff) and from autochthonous production (marsh macrophytes). Unlike most estuarine systems studied to date, which are dominated by algae (phytoplankton and benthic microalgae) and C4 macrophytes, C3 plants are of greater importance in the diets of consumers in this low-salinity creek system.  相似文献   

2.
In order to document the effect of the recent drought and the resulting marine intrusion event on plant-community shifts in a Louisiana estuary, we analyzed two vegetation data sets collected in Barataria estuary in 1997 and 2000 and compared community shifts to surface salinity changes at four points along the estuarine gradient within the study area. We used the major vegetation types identified in our previous research of larger data sets and tested the use of a simple vegetation classification technique. This vegetation classification technique is based primarily on the dominant and co-dominant species, and secondarily on the number of taxa observed. To distinguish vegetation types with similar dominant species but different associated species, the vegetation classification technique used a salinity score derived from the species composition. Surface water salinity increases were reflected by a change in species composition in the mesohaline to fresh marshes. The largest species composition shift observed was the shift from oligohaline wiregrass (species rich vegetation type dominated bySpartina patens) to mesohaline wiregrass (vegetation type dominated byS. patens with few other species). Shifts in vegetation composition may have been enhanced by the presence of the major dominant species at a low abundance in other vegetation types. The vegetation classification technique used could classify over 95% of the stations. This vegetation classification technique provides a simple method to classify Louisiana's coastal vegetation based on plant species composition.  相似文献   

3.
We compared nekton densities over a range of measured flooding conditions and locations withinPhragmites australis andSpartina alterniflora (salt marsh cordgrass) at the Charles Wheeler Salt Marsh, located on the lower Housatonic River estuary in southwestern Connecticut. Nekton were sampled on nine spring high tide events from May to October 2000 using bottomless lift nets positioned between 0–5 and 10–20 m from the creek edge. Flooding depth, duration, and frequency were measured from each vegetation type during each sampling month. Benthic macroinvertebrate density was also measured within each vegetation type in May, July, and September. Frequency of flooding was 52% lower and flooding depth and duration were also significantly reduced inP. australis relative toS. alterniflora. A total of 4,197 individuals representing 7 species, mostlyPalaemonetes pugio (dagger-blade grass shrimp) andFundulus heteroclitus (common mummichog), were captured.P. pugio densities were significantly greater inS. alterniflora as were benthic macroinvertebrate density and taxa richness during May, but not during June or October. Total fish density was not significantly different betweenP. australis andS. alterniflora and was independent of location on the marsh. Significantly more juvenileF. heteroclitus were collected withinS. alterniflora relative toP. australis in June and July, suggesting that recruitment of this species may be lower inP. australis habitat. Fish density generally did not vary predictably across the range of flooding depth and duration; there was a positive relationship between flooding depth and fish density inS. alterniflora. The measured reduction in flooding frequency (52%) withinP. australis at the Housatonic site would result in an average total monthly fish use, expressed as density, of 447 ind m−2 forP. australis and 947 ind m−2 forS. alterniflora. WhenP. australis expansion results in reduction of flooding frequency and duration, nekton community composition can change, access to the marsh surface is reduced twofold, and nursery habitat function may be impaired.  相似文献   

4.
Destruction of tidal wetlands has led to a growing interest in the restoration and creation of new wetland habitat. However, while natural stands of vegetation have been successfully duplicated, less is understood about the establishment of faunal communities in created or restored tidal marshes. Infauna, which may form an important link between detrital production and commercially important finfish and decapods, have received limited attention in vegetated marsh habitats. We examined the infauna, changes in vegetation composition, and selected physical parameters in created marshes of different ages. Infauna were sampled using standard core sampling techniques. Vegetation composition and changes in relative abundance were observed using plot-point techniques. Vegetation plots indicated ongoing replacement ofSpartina alterniflora bySchoenoplectus robustus, a pattern supported by comparisons of vegetation at one of the sites to that reported in a previous study. Infauna exhibited significant differences between sites of different ages, with the intermediate-age site having intermediate densities for several taxa. These results suggest that both infauna and vegetation in created marshes undergo long-term change (ongoing after 10–20 yr), with both the plant and infaunal communities having qualitatively similar overall species composition to natural marsh areas.  相似文献   

5.
  相似文献   

6.
We investigated whether within wetland environmental conditions or surrounding land cover measured at multiple scales were more influential in structuring regional vegetation patterns in estuarine tidal wetlands in the Pacific Northwest, USA. Surrounding land cover was characterized at the 100, 250, and 1,000 m, and watershed buffer scales. Vegetation communities were characterized by high species richness, lack of monotypic zonation, and paucity of invasive species. The number of species per site ranged between 4 and 20 (mean?±?standard deviation?=?10.2?±?3.1). Sites supported a high richness (mean richness of native species 8.7?±?2.8) and abundance of native macrophytes (mean relative abundance 85 %?±?19 %). Vegetation assemblages were dominated by a mix of grasses, sedges, and herbs with Sarcocornia pacifica and Distichlis spicata being common at sites in the oceanic zone of the estuary and Carex lyngbyei and Agrostis stolonifera being common at the fresher sites throughout the study area. The vegetation community was most strongly correlated with salinity and land cover within close proximity to the study site and less so with land cover variables at the watershed scale. Total species richness and richness of native species were negatively correlated with the amount of wetland in the buffer at all scales, while abundance of invasive species was significantly correlated to within wetland factors, including salinity and dissolved phosphorus concentrations. Landscape factors related to anthropogenic disturbances were only important at the 100-m buffer scale, with anthropogenic disturbances further from the wetland not being influential in shaping the vegetation assemblage. Our research suggests that the traditional paradigms of tidal wetland vegetation structure and environmental determinants developed in east coast US tidal wetlands might not hold true for Pacific Northwest wetlands due to their unique chemical and physical factors, necessitating further detailed study of these systems.  相似文献   

7.
This paper examines how perennial Aster tripolium and annual Salicornia procumbens salt marshes alter the biomass, density, taxon diversity, and community structure of benthic macrofauna, and also examines the role of elevation, sediment grain size, plant cover, and marsh age. Core samples were collected on a fixed grid on an intertidal flat in the Westerschelde estuary (51.4° N, 4.1° E) over 5 years (2004–2008) of salt marsh development. In unvegetated areas, macrobenthic biomass, density, and taxon diversity were highest when elevation was highest, benthic diatoms were most abundant, and sediment median grain size was smallest. In contrast, in salt marsh areas, macrobenthic biomass and taxon diversity increased with median grain size, while the effects of elevation and diatom abundance on macrobenthic biomass, density, and diversity were not significant. In fine sediments, macrofaunal community structure in the salt marsh was particularly affected; common polychaetes such as Nereis diversicolor, Heteromastus filiformis, and Pygospio elegans had low abundance and oligochaetes had high abundance. Marsh age had a negative influence on the density of macrofauna, and A. tripolium stands had lower macrofaunal densities than the younger S. procumbens stands. There were no significant effects of marsh age, plant cover, and vegetation type on macrobenthic biomass, taxon diversity, and community structure. The results highlight that ecosystem engineering effects of salt marsh plants on macrofauna are conditional. Organic enrichment of the sediment and mechanical hindering of macrofaunal activity by plant roots are proposed as plausible mechanisms for the influence of the salt marsh plants on macrofauna.  相似文献   

8.
A probabilistic mathematical model of bivalve suspension-feeding in estuaries is based on bivalve abundance, filtering capacities, and water mixing parameters. We applied the model to five regions of the upper Chesapeake Bay, ranging from shallow tidal fresh habitats to deep mesohaline habitats, for the years 1985 to 1987. Model results indicated that existing suspension-feeding bivalves could consume more than 50% of annual primary production in shallow freshwater and oligohaline reaches of the upper Chesapeake Bay and Potomac River. In deep mesohaline portions of the Chesapeake Bay and Potomac River, suspension-feeding bivalves could consume only 10% of primary production. Independent estimates of benthic carbon demand based on benthic production supported the model predictions. Hydrodynamics of large estuaries restrict the potential of benthic suspension-feeders to crop phytoplankton production because the width and depth of these estuaries limit transport of pelagic waters to the littoral flanks of the estuaries where benthic suspension-feeders can be abundant. Benthic suspension-feeders are dominant consumers in shallow segments of the Chesapeake Bay system, but are suppressed in deeper segments. The suppression is below that set by hydrodynamic limits, and may be due to periodic hypoxia or other factors. Our results suggest that the proposed use of suspension-feeding bivalves to improve water quality of large estuaries will be limited by the depth and width of the estuary, unless the bivalves are suspended in the water column by artificial means.  相似文献   

9.
Salt marsh ecosystems provide many critical ecological functions, yet they are subject to considerable disturbance ranging from direct human alteration to increased inundation due to climate change. We assessed emergent salt marsh plant characteristics in the Tuckerton Peninsula, a large expanse (~ 2000 ha) of highly inundated habitat along the southern New Jersey coast, USA. Key salt marsh plant parameters were monitored in the heavily grid-ditched northern segment, Open Marsh Water Management (OMWM) altered central segment, and the shoreline altered southern segment of the peninsula in the summer months of 2011 and 2013. Plant species composition and three metrics of abundance and structure (maximum canopy height, percent areal cover, and shoot density) were examined among marsh segments, along transects within segments, seasonally by month and between years. Despite seasonal or annual variability, the northern segment of the marsh differed in plant species composition from the central and southern segments. This difference was partly due to greater percent areal cover in the northern segment of upper marsh species such as Spartina patens and Distichlis spicata. S. patens also exhibited higher shoot densities in the northern segment than the central segment. Despite the higher abundance of upper marsh species, marsh surface elevations were lower in the northern segment than in the central or southern segments, suggesting the influence of altered hydrology due to human activities. Understanding current variation in the emergent salt marsh vegetation along the peninsula will help inform future habitat change in other coastal wetlands of New Jersey and the mid-Atlantic region subject to natural and anthropogenic drivers.  相似文献   

10.
Laguna de la Leche, north coastal Cuba, is a shallow (≤ 3 m), oligohaline (∼ 2.0-4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ∼6200 to ∼ 4800 cal yr BP, the area was an oligohaline lake. The period from ∼ 4800 to ∼ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ∼ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ∼ 1700 cal yr BP.  相似文献   

11.
Ecological restoration of salt marshes using plantations may enhance the macroinvertebrate community, but little is known about the development of benthic macroinvertebrates after ecological engineering projects in European salt marshes. This study analyzed the environment and the macroinvertebrate community in European salt marshes 3 years after restoration using Spartina maritima plantations in comparison with non-restored and preserved marshes in Odiel Marshes (Southwest Iberian Peninsula). We hypothesized that planting Spartina maritima on intertidal mudflats would increase species richness and diversity (Shannon–Weaver index) of the benthic macroinvertebrate community by increasing environmental heterogeneity, providing feeding resources and improving sediments characteristics. Benthic macrofauna samples (composed mainly of annelids, crustaceans, and mollusks) were sampled in plots of 20 cm?×?25 cm to 5 cm depth between +1.8 and +3.0 m above Spanish Hydrographic Zero. Sediment organic matter content, bulk density, pH, and redox potential were the variables that best explained macroinvertebrate distribution. Restored marshes achieved similar diversity and even higher specific richness than preserved marshes, although with differences in species composition. Non-restored marshes showed the lowest diversity. Restored and preserved marshes did not differ in total abundance or biomass of macroinvertebrates, both being higher than in non-restored marshes. The macroinvertebrate communities in preserved and non-restored marshes showed the largest difference in taxa composition, with restored marshes occupying an intermediate position. Salt marsh restoration using S. maritima increased the complexity (ecological diversity and species richness) and abundance of the benthic macroinvertebrate community. Our study offers new information about the role of salt marsh plants in mediating faunal communities via ecological engineering projects.  相似文献   

12.
We compared nekton use ofVallisneria americana Michx. (submerged aquatic vegetation, SAV) with marsh shoreline vegetation and subtidal nonvegetated bottom (SNB) using a 1-m2 drop sampler in the oligohaline area of Barataria Bay, Louisiana. Mean densities of most abundant species were significantly different among six habitat types. Harris mud crabRhithropanopeus harrisii, Ohio shrimpMacrobrachium ohione, blue crabCallinectes sapidus, daggerblade, grass shrimpPalaemonetes pugio, white shrimpLitopenaeus setiferus (fall), rainwater, killifishLucania parva, naked gobyGobiosoma bosc, code gobyGobiosoma robustum (fall), speckled worm eelMyrophis punctatus (fall), and gulf pipefishSyngnathus scovelli (spring), were much more abundant, and species richness also was greater, inVallisneria than over SNB.Vallisneria supported densities of most species that were similar to those in marsh vegetation, although naked goby and gulf pipefish were more abundant inVallisneria, and speckled worm eel and saltmarsh topminnowFundulus jenkinsi were more abundant in marsh. Within theVallisneria bed, densities of Harris mud crab, rainwater killifish, and speckled worm eel were higher at sites near the marsh (SAV Inside Edge) than at sites more distant from the marsh (SAV Outside Edge), and Ohio shrimp (fall) densities were higher in the interior of the bed than along the edges. The mean size of blue crab was larger in marsh thanVallisneria and large inVallisneria than SNB. White shrimp did not differ in size among habitat types.Vallisneria beds may provide an important nursery habitat for young blue crab and white shrimp that use oligohaline estuarine areas. These SAV beds can provide an alternative structural habitat to emergent vegetation during periods of low water, becauseVallisneria occurs in the subtidal and generally persists throughout the year on the Gulf coast. Species whose young thrive in low-salinity waters and also depend on structure would benefit most fromVallisneria habitat in estuaries.  相似文献   

13.
Nearshore benthic habitats of Biscayne Bay fit the prediction of communities at risk due to their location adjacent to a large metropolitan center (Miami) and being influenced by changes in hydrology through the activities of the Comprehensive Everglades Restoration Plan (CERP). We examine whether the proposed programmatic expansion of mesohaline salinities through the introduction of additional fresh water would result in: (1) increases in seagrass cover; (2) expansion in the distribution and cover of Halodule; and (3) a reduction in the dominance of Thalassia, as hypothesized by CERP. Seagrasses were present at 98 % of sites where they covered 23 % of the bottom. Salinity was the only physical variable with a significant relationship to the occurrence of all SAV taxa. Occurrence of Thalassia, Halimeda, and Penicillus increased significantly with increasing salinity, but Halodule, Syringodium, Laurencia, Udotea, Batophora, Caulerpa, and Acetabularia showed a significant negative relationship with salinity. Mesohaline habitats had higher cover of seagrass and Halodule, and reduced dominance by Thalassia. Thus, we expect increases in the extent of mesohaline habitats to achieve the established CERP goals. We also examined the nutrient content of seagrass blades to evaluate whether: (1) nutrient availability is higher in areas close to canal discharges; and (2) tissue nutrient levels are related to seagrass abundance. The low abundance of Thalassia along the shoreline is not only due to its exclusion from low-salinity environments but also by higher nutrient availability that favors Halodule. Percent N and P, and N:P ratios in seagrass tissue suggest that Biscayne Bay receives high N inputs and is P-limited. Thus, increased P availability may facilitate an expansion of Halodule. The data presented suggest that increased mesohaline salinities will increase seagrass abundance and support co-dominance by Halodule and Thalassia as hypothesized, but raise concerns that current high N availability and increases in P may prompt a shift away from seagrass-dominated to algal-dominated communities under scenarios of enhanced fresh water inputs.  相似文献   

14.
The salt marsh surface is not a homogeneous environment. Rather, it contains a mix of different microhabitats, which vary in elevation, microtopography, and location within the estuarine system. These attributes act in concert with astronomical tides and meteorological and climatological events and result in pulses of tidal flooding. Marsh hydroperiod, the pattern of flooding events, not only controls nekton access to marsh surface habitats directly but may also mediate habitat exploitation through its influence on other factors, such as prey abundance or vegetation stem density. The relative importance of factors affecting marsh hydroperiod differ between the southeast Atlantic and northern Gulf of Mexico coasts. Astronomical tidal forcing is the primary determinant of hydroperiod in Atlantic Coast marshes, whereas predictable tides are often overridden by meteorological events in Gulf Coast marshes. In addition, other factors influencing coastal water levels have a proportionately greater effect on the Gulf Coast. The relatively unpredictable timing of marsh flooding along the Gulf Coast does not seem to limit habitat utilization. Some of the highest densities of nekton reported from salt marshes are from Gulf Coast marshes that are undergoing gradual submergence and fragmentation caused by an accelerated rise in relative sea level. Additional studies of habitat utilization are needed, especially on the Pacific and Atlantic coasts. Investigations should include regional comparisons of similar microhabitats using identical quantitative sampling methods. Controlled field experiments are also needed to elucidate the mechanisms that affect the habitat function of salt marshes.  相似文献   

15.
Contemporary deposition (artificial marker horizon, 3.5 years) and long-term accumulation rates (210Pb profiles, ~150 years) of sediment and associated carbon (C), nitrogen (N), and phosphorus (P) were measured in wetlands along the tidal Savannah and Waccamaw rivers in the southeastern USA. Four sites along each river spanned an upstream-to-downstream salinification gradient, from upriver tidal freshwater forested wetland (TFFW), through moderately and highly salt-impacted forested wetlands, to oligohaline marsh downriver. Contemporary deposition rates (sediment, C, N, and P) were greatest in oligohaline marsh and lowest in TFFW along both rivers. Greater rates of deposition in oligohaline and salt-stressed forested wetlands were associated with a shift to greater clay and metal content that is likely associated with a change from low availability of watershed-derived sediment to TFFW and to greater availability of a coastal sediment source to oligohaline wetlands. Long-term accumulation rates along the Waccamaw River had the opposite spatial pattern compared to contemporary deposition, with greater rates in TFFW that declined to oligohaline marsh. Long-term sediment and elemental mass accumulation rates also were 3–9× lower than contemporary deposition rates. In comparison to other studies, sediment and associated nutrient accumulation in TFFW are lower than downriver/estuarine freshwater, oligohaline, and salt marshes, suggesting a reduced capacity for surface sedimentation (short-term) as well as shallow soil processes (long-term sedimentation) to offset sea level rise in TFFW. Nonetheless, their potentially large spatial extent suggests that TFFW have a large impact on the transport and fate of sediment and nutrients in tidal rivers and estuaries.  相似文献   

16.
The spatial scale of habitat selection has become a prominent concept in ecology, but has received less attention in coastal ecology. In coastal marshes, broad-scale marsh types are defined by vegetation composition over thousands of hectares, water-level management is applied over hundreds of hectares, and fine-scale habitat is depicted by tens of meters. Individually, these scales are known to affect wetland fauna, but studies have not examined all three spatial scales simultaneously. We investigated wetland bird habitat selection at the three scales and compared single- and multiscale models. From 2009 to 2011, we surveyed marsh birds (i.e., Rallidae, bitterns, grebes), shorebirds, and wading birds in fresh and intermediate (oligohaline) coastal marsh in Louisiana and Texas, USA. Within each year, six repeated surveys of wintering, resident, and migratory breeding birds were conducted at >100 points (n?=?304). The results revealed fine-scale factors, primarily water depth, were consistently better predictors than marsh type or management. However, 10 of 11 species had improved models with the three scales combined. Birds with a linear association with water depth were, correspondingly, most abundant with deeper fresh marsh and permanently impounded water. Conversely, intermediate marsh had a greater abundance of shallow water species, such as king rail Rallus elegans, least bittern Ixobrychus exilis, and sora Porzana carolina. These birds had quadratic relationships with water depth or no relationship. Overall, coastal birds were influenced by multiple scales corresponding with hydrological characteristics. The effects suggest the timing of drawdowns and interannual variability in spring water levels can greatly affect wetland bird abundance.  相似文献   

17.
Densities of juvenile and postlarval Farfantepenaeus aztecus, F. duorarum, and Litopenaeus setiferus were compared in vegetated fringing marsh and adjacent nonvegetated areas over a range of environmental conditions in Mobile Bay, Alabama. Densities of all three species were significantly greater in vegetated than nonvegetated areas, with 82% of all penaeids found in vegetated areas. Among vegetated sites, significantly lower densities were found in oligohaline areas, whereas mesohaline areas had the highest densities. Significant positive correlations were found between density and salinity for F. aztecus and F. duorarum but not for L. setiferus. Emergent vegetation is important habitat for F. aztecus and F. duorarum as reported from other locations, and our data support a similar conclusion for L. setiferus. Shoreline emergent marsh vegetation is particularly important in Mobile Bay as it represents the only extensive vegetated habitat readily available to F. aztecus, F. duorarum, and L. setiferus.  相似文献   

18.
The Druze Marsh is a spring‐fed wetland in northeast Jordan that dried out completely in the late 1980s. This drying and subsequent drop in the water table permitted study of the marsh stratigraphy and a search for prehistoric occupations. In this paper, we combine detailed sedimentological analysis of eight stratigraphic sections in the bed of the former Druze Marsh to reconstruct the landscapes used by hominins since the Middle Pleistocene. The results show that fluctuation in water availability over the past 350 ka had dramatic impacts on the size and depth of the wetlands. Pleistocene occupations in the Druze Marsh correspond to relatively dry climatic conditions when the wetland was reduced in size, suggesting the Druze Marsh acted as a desert refugium for hominins during adverse climatic conditions. Such refugia have important implications for hominin demography, continuity, and/or extinction in the Syro‐Arabian Desert. Moreover, the Druze Marsh is positioned at the north end of the Wadi Sirhan depression that connects the Levantine Corridor to the west and Arabian Peninsula to the southeast. Therefore, during wetter climates, paleolakes and river networks around the Druze Marsh may have provided an additional inland route for hominins dispersing between Africa, Eurasia, and the Arabian Peninsula.  相似文献   

19.
We sampled epiphytic and benthic macriinvertebrates in 20 beds of submersed vegetation throughout the Hudson River estuary to assess the importance of plant beds in providing habitat for macroinvertebrates and to determine which characteristics of plant beds affected the density and composition of macroinvertebrates. Macroinvertebrate densities in plant beds were 4–5 times higher, on average, than densities in unvegetated sediments in the Hudson. The macroinvertebrate community in plant beds was dominated by chironomid midges, oligochaete worms, hydroids, gastropods, and amphipods. Many species of macroinvertebrates were found chiefly on submersed plants, showing that plant beds are important in supporting biodiversity in the Hudson. Macroinvertebrates were most numerous in beds with high plant biomass and in the interiors of beds, whereas neither bed size nor position along the length of the estuary affected macroinvertebrate density. Community composition varied strongly with position along the river (freshwater versus brackish), habitat (epiphytic versus benthic), and position within the bed (edge versus interior). Plant biomass also influenced macroinvertebrate community composition, but bed area had relatively little influence.  相似文献   

20.
Compared to benthic and water-column invertebrate assemblages, considerably less is known about terrestrial arthropods inhabiting estuarine wetlands despite their importance to tidal wetland biodiversity and productivity. We also need to know more about how human modification of estuaries, including efforts to restore estuarine wetlands, affects these assemblages. To address this knowledge gap, we assembled data from multiple studies on terrestrial arthropod assemblages from 87 intertidal wetland sites in 13 estuaries along the west coast of North America. Arthropods were sampled between 1998 and 2013 with fallout traps deployed in wetlands for 1 to 3 days at a time. We describe patterns in the abundance and taxonomic composition of terrestrial arthropods and evaluate the relative ability of natural and anthropogenic factors to explain variation in abundance and composition. Arthropod abundance was highly variable. Vegetation assemblage, precipitation, and temperature best explained variation in arthropod abundance, while river discharge, latitude, and developed and agricultural land cover surrounding sampling sites were less important. Arthropod abundance rapidly achieved levels of reference wetlands after the restoration of tidal influence to leveed wetlands, regardless of surrounding land cover. However, arthropod assemblage composition was affected by the amount of developed land cover as well as restoration age. These results suggest that restoration of tidal influence to leveed wetlands can rapidly restore some components of estuarine wetland ecosystems but that recovery of other components will take longer and may depend on the extent of anthropogenic modification in the surrounding landscape.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号