Loss Of Ponds Research Articles

Simple Patchy-Based Simulators Used to Explore Pondscape Systematic Dynamics

Thousands of farm ponds disappeared on the tableland in Taoyuan County, Taiwan since 1920s. The number of farm ponds that have disappeared is 1,895 (37%), 2,667 ponds remain (52%), and only 537 (11%) new ponds were created within a 757 km2 area in Taoyuan, Taiwan between 1926 and 1960. In this study, a geographic information system (GIS) and logistic stepwise regression model were used to detect pond-loss rates and to understand the driving forces behind pondscape changes. The logistic stepwise regression model was used to develop a series of relationships between pondscapes affected by intrinsic driving forces (patch size, perimeter, and patch shape) and external driving forces (distance from the edge of the ponds to the edges of roads, rivers, and canals). The authors concluded that the loss of ponds was caused by pond intrinsic factors, such as pond perimeter; a large perimeter increases the chances of pond loss, but also increases the possibility of creating new ponds. However, a large perimeter is closely associated with circular shapes (lower value of the mean pond-patch fractal dimension [MPFD]), which characterize the majority of newly created ponds. The method used in this study might be helpful to those seeking to protect this unique landscape by enabling the monitoring of patch-loss problems by using simple patchy-based simulators.

Historical Changes in the Distribution and Abundance of Constructed Ponds in Response to Changing Population Density and Land Use

In the United States most ponds are constructed for varying purposes and at varying historical rates, yet little attention is paid to their presence or ecological impact. We evaluated changes in pond density, landscape position with respect to streams, and rates of pond construction and loss within a watershed in southeastern Pennsylvania and northern Delaware that has experienced increases in population density and associated changes in land use. Based on aerial photographs taken on nine dates between 1937 and 2005, and maps prepared in 1883, abundances of all water bodies declined slightly from 1883 to 1937, then increased 18-fold during the remainder of the study period. Most ponds in 1883 (94.6%) were ‘in-line’ impoundments receiving stream inflows, whereas ‘off-line’ water bodies without inflows represented 77.3% of total ponds in 2005. Pond loss rates averaged 3.2%/year between 1883 and 1946, but declined to 0.16%/year between 1946 and 2005. Because of their changing abundance and landscape position, ponds are assuming rapidly changing ecological roles within the watershed.

Mediterranean amphibians and the loss of temporary ponds: Are there alternative breeding habitats?

In farmland landscapes, amphibians often breed in artificial water bodies, which may offset at least partly the loss of natural wetlands associated with agricultural intensification. It is possible, however, that artificial habitats provide conditions for a minor proportion of the regional species pool, benefiting just a few widespread generalists. We assessed these alternative views by documenting the decline of temporary ponds in a Mediterranean farmland landscape between 1991 and 2009, and by estimating the occupancy of natural (temporary ponds and streams) and artificial water bodies (farm ponds, irrigation channels and drainage ditches) by amphibians across the breeding season (February–June 2010). We used hierarchical Bayesian dynamic multi-species occupancy modelling to control for differences in detectability across species, sampling occasions and habitat types. Over two decades the farmland landscape lost 56% of its temporary ponds, of which 89.3% were destroyed through agricultural activities such as cultivation, conversion to permanent farm ponds, and drainage. The survival rate of ponds was lowest within an irrigated perimeter, and there was no positive effect of protection by a natural park. Estimated species richness per site was at least twice as high in temporary ponds as in the other habitat types. From the 10 amphibian species recorded, seven had the highest occupancy in temporary ponds, and were absent or occurred rarely in artificial habitats. Only a single generalist species was widespread in farm ponds and irrigation channels. The results suggest that artificial water bodies are unlikely to sustain populations of most amphibian species in Mediterranean intensive farmland. Conservation efforts should be directed at protecting the temporary ponds still remaining within the farmed landscape, and at restoring or creating new temporary ponds where these have been lost during the last decades.

Estimation of Average Annual Removal Efficiencies of Wet Detention Ponds Using Continuous Simulation

A curve-number-based, planning level, macrospreadsheet model wet pond annual efficiency simulation model (WEANES) has been developed to predict the average annual removal efficiencies (AARE) of wet detention ponds based on mass pollutant loadings. The model can be used as a design, planning, and permitting tool. WEANES uses the following three processes: (1) converts daily rainfall hyetographs to hydrographs using the curve-number (CN)—based Santa Barbara urban hydrograph method; (2) converts the inflow hydrograph to an outflow hydrograph from the wet pond outlet structure through routing; and (3) calculates annual inflow and outflow pollutant loads and pond efficiency. The model uses historical, site-specific, multiyear, rainfall data available from National Oceanic and Atmospheric Administration climatological stations. Required input parameters are: (1) watershed parameters (drainage area, pervious CN, directly connected impervious area, and time of concentration); (2) pond parameters (control and overflow elevations, pond side slopes, and surface areas at control elevation and pond bottom); (3) outlet structure parameters; (4) pollutant event mean concentrations; and (5) pond loss rate, which is defined as the net loss due to evaporation, infiltration, and water reuse. This paper provides an example of the model calibration and validation process for an existing wet pond. The effect of watershed and pond parameters on AARE is examined through sensitivity analysis. The WEANES-computed AARE values for total suspended solids ranged from 75.9 to 84%, whereas the U.S. EPA model predicted removal efficiencies of greater than 99%. The WEANES model can provide the user with greater flexibility while maintaining the simplicity of the U.S. EPA model.

Environmental heterogeneity affects input, storage, and transformation of coarse particulate organic matter in a floodplain mosaic

Quantifying spatial and temporal dynamics of organic matter (OM) is critical both for understanding ecosystem functioning and for predicting impacts of landscape change. To determine the influence of different habitats and coarse particulate OM (CPOM) types upon floodplain OM dynamics, we quantified aerial input, lateral surface transfer, and surface storage of CPOM over an annual cycle on the near-natural floodplain of the River Tagliamento in NE-Italy. Using these data, we modelled floodplain leaf dynamics, taking account of the spatial distribution and hydrologic connectivity of habitats, and using leaf storage as a response variable. Mean aerial CPOM input to the floodplain was similar from riparian forest and islands, but surface transfer was greater from islands, supporting the suggestion that these habitats act as “islands of fertility” along braided rivers. Leaves were the lateral conveyor of energy to more open parts of the floodplain, whereas CPOM was mainly stored as small wood in vegetated islands and riparian forest. Simulating the loss of habitat diversity (islands, ponds) decreased leaf storage on the whole floodplain, on exposed gravel and in large wood accumulations. In contrast, damming (loss of islands, ponds and floods plus floodplain overgrowth) greatly increased storage on exposed gravel. A random shuffle of habitats led to a storage increase on exposed gravel, while that in large wood accumulations and ponds declined. These results disentangle some of the complexities of CPOM dynamics in floodplain ecosystems, illustrate the value of models in understanding ecosystem functioning at a landscape level, and directly inform river management practice.

Modelling Geographic Information System with Logistic Regression in Irrigation Ponds, Taoyuan Tableland

Abstract This paper examines historical trends in land-use transformation taking place in the farm-pond areas, one of the potential ecotourism sites, of Taoyuan Tableland, Taiwan. It demonstrates that irrigation system and urbanization are the key factors undermining and catalyzing changes in pondscape. Therefore, land transactions increased overall transformation of land use in the entire areas. Unregulated urbanization has given rise to complex organic urban structures which predominantly expanding horizontally. The emerging land use pattern indicates a mismatch with the widely pondscapes and farmlands. Land use changes over two time periods, 1926 to 1960 and 1960 to 1999, were analyzed to demonstrate how enforcing land-use policies can influence the direction and magnitude of pondscape change. First, adoption of a grand canal irrigation system has resulted in the internal restructuring of agricultural land use from traditional farm-pond irrigation to more diversified water sources, such as the sources from ditch, canal, or reservoirs. Spatial dependency of pondscape changes could be identified between the northern irrigation system (Taoyuan Main Canal) from 1926 to 1960; and the southern irrigation system (Shihmen Main Canal) from 1960 to 1999, later. The relationship between pond area and pond loss was calculated, illustrated, and discussed. A statistical model, logistic regression, was designed to examine how area-per-se effects of farm ponds have driven their loss in Taoyuan Tableland.

Spatial and temporal variability of aquatic habitat use by amphibians in a hydrologically modified landscape

SUMMARY 1. Habitat loss is a major driver of biodiversity decline worldwide. Temporary waterbodies are especially vulnerable because they are sensitive both to human impact and to climatic variations. Pond-breeding amphibians are often dependent on temporary waterbodies for their reproduction, and hence are sensitive to loss of temporary ponds. 2. Here we present the results of a 5-year study regarding the use of temporary aquatic habitats by amphibians in a hydrologically modified area of Eastern Europe (Romania). The annual number of aquatic habitats varied between 30 and �120. Each aquatic habitat was characterised by a number of variables such as: ‘type’ (pond, drainage ditch and archaeological ditch), ‘hydroperiod’ (number of weeks the ponds were filled in a given year), ‘depth’ (cm), ‘area’ (m 2 ) and the density of predatory insects (‘predation’). The turnover rate for each amphibian species for each wetland was calculated based on the pond occupancy. 3. Eight amphibian species were recorded from the aquatic habitats. Hydroperiod was the most important variable, positively influencing wetland use by amphibians and their reproductive success. Most species preferred drainage ditches for reproduction, and the reproductive success was highest in this habitat type every year. For most of the species, the local extinction rate was higher than the colonisation rate in the first 4 years, but the situation reversed in the last year of the study when wetland use by amphibians sharply increased because of high rainfall. 4. This study confirms the importance for amphibians of maintaining and managing aquatic habitat diversity at small spatial scales. Man-made aquatic habitats such as drainage ditches may be important habitats for amphibians, and this should be considered in restoration activities.

Ponds and the importance of their history: an audit of pond numbers, turnover and the relationship between the origins of ponds and their contemporary plant communities in south-east Northumberland, UK

An increasing focus of interest in ponds over the last two decades arose largely because of concerns at the loss of ponds in intensively developed landscapes. In the UK, pond numbers declined from approximately 800,000 in the nineteenth century to 200,000 by the 1980s. Since then pond numbers have started to increase. The focus on overall pond numbers overlooks the importance of the history and origins of different pond types. This study combines a detailed map based audit of pond numbers in south-east Northumberland, UK, recorded at seven time intervals since the mid-nineteenth century with a survey of contemporary plant communities in ponds with known and distinct histories to examine changes to numbers of ponds and communities associated with ponds with different origins. 222 ponds were recorded in the study area in the mid-nineteenth century, 257 in 2005/08. However, only 23 of the original ponds had survived with substantial losses and gains at all the map survey dates linked to changed land use from agriculture to coal mining then development of nature reserves and golf courses. Contemporary ponds on nature reserves, golf courses and subsidence ponds supported rather different plant communities to each other, with non-native invasives in golf and nature reserve sites, whilst individual reserves differed from one another perhaps due to intentional planting. Surviving old farm ponds were usually degraded. The results show that the history of ponds in a region can create an important cultural biodiversity which pond conservation strategies should incorporate.

Amphibian pond loss as a function of landscape change – A case study over three decades in an agricultural area of northern France

Agricultural reform and infrastructural development are among the major drivers of biodiversity loss and landscape homogenization worldwide. Ponds and other small stagnant water bodies are crucial for maintaining regional biodiversity, yet they are vulnerable to human induced landscape change. We investigated for 199 ponds in the ‘département’ Pas-de-Calais in north-western France if pond persistence ( n = 86, 43%) or disappearance ( n = 113, 57%) was related to wider changes in the landscape, over the period 1975–2006. Landscape data were obtained from aerial photographs (1963), two ASTER satellite images (2001 and 2003) and observations on the ground (1975 and 2006) and land use around the ponds was described over concentric circles with five different radii in the 100–1000 m range. Overall, pond disappearance was associated with a decrease in grassland and an increase in arable fields around the ponds. We found that the small, man-made cattle ponds, with either natural substrate or concrete drinking troughs, were more often affected than the larger, semi-natural ponds. Since the cattle ponds are regularly used for amphibian reproduction, their massive abandonment therewith weakens the population network and puts the local occurrence of some of the rarer species at risk. Spatial extrapolation of models on pond persistence allowed the identification of areas most at risk of further pond loss. We suggest that local amphibian conservation efforts will be the most effective if the focus is on the marshes and dune areas and on pond preservation in the remaining grasslands.

Using spatial network structure in landscape management and planning: A case study with pond turtles

Connectivity is currently a central issue in landscape management and planning for the conservation of wildlife species occupying scarce habitat patches. In recent years, this issue has increasingly been addressed using methodologies based on spatial network analysis. Here, we propose a hybrid approach based on network analysis tools and empirical habitat suitability models to integrate connectivity on decision-making. The study is focused on a pond system used by the European pond turtle, Emys orbicularis, in a coastal area in southwestern Iberia. The main objective of the study was to illustrate how the output of graph models may be useful to guide habitat management and planning. We assessed ponds according to three complementary structural and functional properties derived from a graph model: (1) pond importance as measured by the sensitivity of the overall connectivity to each pond loss, (2) pond coreness, used to identify the most cohesive pond subsystems and (3) pond betweenness, which measure the importance of ponds as stepping stones. The graph model took into account a resistance-to-movement surface, the maximum traveled distance and a habitat suitability model based on field sampling. Pond importance and coreness were shown to be positively related to occupancy, especially by turtle's youngest age classes, suggesting an important contribution of connectivity attributes for turtle populations. We discuss the ways these pond connectivity-related attributes may be helpful to assist and optimize management efforts for the conservation of the European pond turtle in the study area.

Sustainability of High Arctic Ponds in a Polar Desert Environment

Arcti c wetland environments are sensitive to ongoing climate change as seen by the recent loss of lakes and ponds in southern Alaska, Siberia, and northern Ellesmere Island, Canada. A clearer picture of the mechanisms accounting for these losses or the persistence of ponds is presently required. To better understand and quantify the hydrologic processes that are leading to the sustainability or demise of High Arctic ponds, a detailed study was conducted during the summer seasons of 2005 and 2006 at Somerset Island, Nunavut (72˚43' N, 94˚15' W). A water balance framework that quantifies water inputs, losses, and storage was employed on four ponds situated in three broad geomorphic areas (coastal, bedrock, and glacial terrain, which includes plateau and moraine). The initial snow cover amount influenced the water level pattern for the summer season. Large end-of-winter snow accumulations in the deep Bedrock pond ensured large initial water storage and seasonal sustainability despite variable climatic conditions and a coarse substrate, which encouraged subsurface outflow. Connectivity to a stream draining an upland area and a melting late-lying snowbed nearby allowed the small Moraine pond to maintain stable water levels throughout both years. Sandy soils typical of the Coastal and Plateau ponds favored seepage and subsurface water losses, leading to desiccation of these ponds during dry periods. Lateral water losses from the Coastal pond were enhanced by the presence of a downslope frost crack that formed a steep hydraulic gradient with the pond. High initial snowfall and substantial rain maintain pond water levels, but in years with low snowfall and dry conditions, ponds are vulnerable to disappearance unless a range of dependable hydrological linkages exists.

Farmland birds and resource protection in the UK: Cross-cutting solutions for multi-functional farming?

Farmland bird declines in Europe are well documented. In the UK, agri-environment schemes are key mechanisms for reversing the declines of birds and other farmland biodiversity, but recent reviews suggest that wet habitats might be a gap in provision by these schemes. Important resources provided by wet habitats include: (i) damp soil, for probing species; (ii) permanent water to provide water-dependent invertebrates, as a source of food; (iii) bare or sparsely vegetated ground in the draw-down zone, to improve access to food; (iv) rank emergent vegetation for nesting. However, wet habitats have been lost from farmland as a result of loss of ponds and filling of ditches, as well as the effective removal of water from fields by surface run-off, itself affected by soil compaction, and extensive under-field drainage. The efficient removal of water from fields can cause problems downstream, both through flooding, and diffuse pollution. Regular farmland pollutants include pesticides, nitrogen, phosphorus and sediment, leading to environmental problems such as eutrophication and reduced quality of drinking water. Major new political instruments, such as the Water Framework Directive, will aim to reduce the impact of this diffuse pollution from agriculture. A variety of solutions to diffuse pollution, such as conservation tillage, buffer strips at field edges, and small constructed wetlands, could simultaneously provide some of the resources required by farmland birds. We suggest that future agri-environment schemes, to be truly multifunctional, could focus on bringing these diverse objectives together.

The Importance of Beaver Ponds to Coho Salmon Production in the Stillaguamish River Basin, Washington, USA

AbstractThe use of beaver Castor canadensis ponds by juvenile coho salmon Oncorhynchus kisutch and other fishes has been well established. However, the population‐level effects on coho salmon resulting from the widespread removal of millions of beaver and their dams from Pacific Coast watersheds have not been examined. We assessed the current and historic distributions of beaver ponds and other coho salmon rearing habitat in the Stillaguamish River, a 1,771‐km2 drainage basin in Washington and found that the greatest reduction in coho salmon smolt production capacity originated from the extensive loss of beaver ponds. We estimated the current summer smolt production potential (SPP) to be 965,000 smolts, compared with a historic summer SPP of 2.5 million smolts. Overall, current summer habitat capacity was reduced by 61% compared with historic levels, most of the reduction resulting from the loss of beaver ponds. Current summer SPP from beaver ponds and sloughs was reduced by 89% and 68%, respectively, compared with historic SPP. A more dramatic reduction in winter habitat capacity was found; the current winter SPP was estimated at 971,000 smolts, compared with a historic winter SPP of 7.1 million smolts. In terms of winter habitat capacity, we estimated a 94% reduction in beaver pond SPP, a 68% loss in SPP of sloughs, a 9% loss in SPP of tributary habitat, and an overall SPP reduction of 86%. Most of the overall reduction resulted from the loss of beaver ponds. Our analysis suggests that summer habitat historically limited smolt production capacity, whereas both summer and winter habitats currently exert equal limits on production. Watershed‐scale restoration activities designed to increase coho salmon production should emphasize the creation of ponds and other slow‐water environments; increasing beaver populations may be a simple and effective means of creating slow‐water habitat.

The importance to ardeids of the deep bay fish ponds, Hong Kong

This study examines the value of commercial fish ponds around the Deep Bay wetlands, Hong Kong, for herons and egrets. Ardeid use of fish ponds for feeding depends on season, species and age. Winter use was greatest by Cattle Egrets Bulbucus ibis and Little Egrets Egretta garzetta, with up to 100 and 49·3% of the individuals in the study area, respectively, using this habitat. Summer use was highest by Chinese Pond Herons Ardeola bacchus (63·4% of individuals in the study area). The flight lines of Chinese Pond Herons breeding locally revealed that 72% landed around fish ponds. Juvenile Chinese Pond Herons made significantly greater use of fish ponds than adults. Recent fish pond loss due to development is likely to have caused declines in both the number of certain ardeids wintering around Deep Bay, and the number of Little Egrets breeding at a local egretry.

A census of ponds in Cheshire, North West England

1. Of the 41 564 small water bodies (‘ponds’) identified on Ordnance Survey maps of Cheshire in ca 1870, 61% had disappeared by the early 1990s. 2. Pond loss has taken place across the county and is associated with a number of different replacement land-uses; loss rates are highest in areas of urban development. 3. Using aerial photography, only 45% of extant ponds show areas of open water, many being completely overshaded by trees or with substantial emergent vegetation. 4. The effects of pond loss are now being felt in increasing fragmentation of the total resource; the density of wet ponds over the entire county has fallen from 17.8 km−2 (ca 1870) to 3.25 km−2 (1992/93), and the ‘connectedness’ of the pond landscape has been similarly reduced. © 1997 John Wiley & Sons, Ltd.

A survey of pond loss in Essex, South‐east England

Abstract1. Sample areas of the county were used to estimate pond loss. An extensive survey used only maps while a smaller, intensive survey combined maps with a field study. In total, 283.43 km2 were surveyed, approximately 7% of the total area.2. Fifty‐five per cent of the ponds present in 1870 had disappeared by 1960 with the greatest loss occurring between 1920 and 1960.3. Loss of ponds in agricultural locations contributed most to this because of their high initial number and their high rates of loss. Percentage losses of large and small ponds were greater than for medium‐sized ponds.4. A field survey showed that a further 23% of a random sample of ponds shown on maps of 1960 could not be found in 1989. Overall loss rates for the period 1870–1989 are estimated to be 68.6% for the extensive area and 54.8% for the intensive area.