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1.
  1. Ecoacoustics is increasingly being used to monitor species populations and to estimate biodiversity in marine ecosystems, but the underwater soundscapes of freshwater environments remain largely unexplored in this respect. Few studies exist concerning the acoustic diversity of ponds, but because aquatic plants and many arthropods such as Coleoptera and Hemiptera are known to produce sound, there is potential to use ecoacoustic techniques to monitor changes in biodiversity and conservation value.
  2. This pilot study compares the underwater soundscapes of recently restored open-canopy ponds and unmanaged highly terrestrialized ponds situated in an arable agricultural landscape of North Norfolk, UK, in order to assess the benefits of farmland pond restoration.
  3. Daytime sound recordings were made for 10 min in each pond and analysed primarily for arthropod stridulations. In addition, six commonly used acoustic indices were calculated to assess the soundscape biodiversity between the unmanaged and the restored ponds. The stridulations of three diving beetle species (Dytiscidae) were recorded in tank studies to assess the potential for individual species recognition from underwater sound capture.
  4. Sound-type richness and abundance, as estimated by visually and aurally identifying arthropod stridulation from spectrograms, were significantly higher in the restored open-canopy ponds compared with the unmanaged terrestrialized ponds. In addition, the acoustic indices ‘acoustic complexity’ and ‘biodiversity index’ were significantly higher in restored open-canopy ponds than in unmanaged terrestrialized ponds.
  5. The three dytiscid water beetle species recorded in a tank were found to produce distinctive and recognizable sounds, indicating potential to create an audio reference library that could be used for automatic acoustic monitoring of freshwater arthropods.
  6. Pond soundscapes are rich in biological information and this study suggests that, with further development, automated passive ecoacoustic monitoring could be an effective non-invasive technique for assessing pond conservation value and pond restoration and management success.
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2.
3.
  1. Freshwater communities and especially pond‐breeding amphibians are extremely vulnerable to land‐use change, alien species introductions and the use of pesticides or other toxic chemicals, as reflected in their worldwide decline. Effective conservation and management of ponds requires a better understanding of the biotic and abiotic factors that shape diversity patterns and species distribution, especially in cases of habitat loss
  2. The present study aimed to reveal and classify which pond and landscape characteristics are the most important determinants for the occurrence patterns of amphibian species as well as for the overall amphibian species richness in an urban pond network. To achieve this aim, 17 biotic and abiotic variables were measured for 61 ponds and the dataset was analysed by means of a machine‐learning approach, suitability indices and co‐occurrence modelling
  3. The highest probability of Triturus macedonicus occurrence was found at fishless artificial and semi‐natural ponds. The persistence of Lissotriton graecus in ponds was predicted by high pond connectivity and the absence of fish reflecting the species dispersive potential. Pelophylax kurtmuelleri showed a higher probability of occurrence with increased pond connectivity and macrophyte cover.
  4. Amphibian species richness was higher in fishless ponds with well‐oxygenated waters located in sites with a low to intermediate road density network. Ponds categorized as ‘average’ in terms of newt suitability were more frequently inhabited by fish than Triturus macedonicus. Alien fish species showed negative associations with both newt species, while both newt species showed a positive association between them.
  5. The results support the view that conserving a greater number of water bodies with increased landscape connectivity and without any fish presence could provide amphibian species with alternative habitat choices, especially in sites with human pressure where pond stability is at stake owing to continuous landscape changes.
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4.
Abstract  Floodplain borrow pits created during dike construction for flood protection along regulated lowland rivers are suggested as convenient surrogate habitats for fish communities where natural floodplain features have been lost. Fish community structure and reproduction success in three borrow pits located in the channelised floodplain of the River Dyje, Czech Republic were studied over 3 years. Short-term floods supported the spawning of phytophilic and phyto-lithophilic species; batch spawners capitalised on late summer flood conditions. The highest species richness of 0+ juvenile fishes occurred at sites with extended periods of flooding, at least for 2 months. Flooded vegetation was inhabited mainly by juvenile cyprinids, while 0+ percids were distributed evenly along the littoral zone. Shoreline remained bare even during higher water levels before complete inundation because of the steep banks, and therefore fish were not able to benefit from higher water levels. Borrow pits appear to function as a substitute habitat for fish and their reproduction, but only if they are properly constructed with shallow areas providing appropriate nursing conditions for 0+ fish growth and survival.  相似文献   

5.
  • 1. A high proportion of ponds are temporary in nature, although the biodiversity value of such sites is still poorly recognized. This work explores the plant and macroinvertebrate communities of 76 temporary and fluctuating water bodies in two regions of southern England (Lizard Peninsula, Cornwall and New Forest, Hampshire) that have retained high pond densities. The ecology and conservation status of sites is examined, and comparisons made with ponds elsewhere in England and Wales.
  • 2. Lizard and New Forest ponds supported 119 plant and 165 macroinvertebrate species respectively. Patterns of community similarity for plants and macroinvertebrates were highly concordant, taxa being related in a similar manner to measured environmental variables including pond area, depth, pH and water chemistry.
  • 3. Patterns of pond occupancy revealed that most species were locally rare, over half occurring in less than 10% of ponds, and less than 10% being recorded from more than 50% of sites. More than 50% of ponds supported at least one nationally rare plant and almost 75% at least one nationally rare macroinvertebrate. These taxa occupied a wide range of pond types in each region, and did not have predictably different ecologies from common species.
  • 4. Comparisons with ponds elsewhere in England and Wales revealed that Lizard and New Forest communities are nationally distinct, being most similar to ponds in areas of low intensity agriculture elsewhere in western Britain. Individual ponds in both regions supported more nationally rare taxa, on average, than ponds sampled in the national survey.
  • 5. Ponds in the two areas have high conservation value, both regionally and nationally, supporting almost 75% of the global species richness of temporary ponds sampled across England and Wales. Within each region, many taxa are found in relatively few sites, and effective conservation of pond biodiversity will require a regional management approach.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

6.
7.
  • 1. Ponds are a valuable resource for the conservation of freshwater biodiversity, but are often extremely numerous in a given area, making assessment of the conservation value of individual sites potentially time consuming.
  • 2. The use of indicator taxa, the species richness of which is representative of total site species richness, may provide one way to improve the efficiency of survey work. However, such indicators are poorly developed for freshwater systems.
  • 3. A data set was used describing the occurrence of macroinvertebrate taxa in ponds in Oxfordshire, UK, to assess the extent to which variation in the species richness of selected taxa most consistently represented variation in all other taxa.
  • 4. Coenagriidae (Odonata) and Limnephilidae (Trichoptera) reflected the variation in species richness of other taxa most consistently, with Coenagriidae showing the best overall performance as an indicator taxon.
  • 5. For both suggested indicator taxa, selection of sites based solely on the presence of at least one species of indicator would represent over 95% of all species recorded across all sites.
  • 6. Further investigation in different geographical regions is necessary to establish whether these relationships are consistent over a wider area.
Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

8.
1. Macrophyte assemblages from 50 ponds throughout the Northumberland coastal plain were surveyed together with adjacent landscape, pond morphology and physical and chemical variables. 2. TWINSPAN classification and CANOCO ordinations suggested that, whilst distinct macrophyte assemblages recurred, relationships of assemblages to environmental variables were weak. Geographical variables (northing, easting and altitude) plus extent of drying out were the most important variables in the CANOCO ordination linking pond types and environmental factors. Most assemblages could be found across a wide range of conditions. Classifications using only aquatic or emergent taxa gave different results. 3. Regression analyses suggested that total species richness of aquatic taxa increased with greater area of deeper water and pH. Emergent taxa richness increased with pond area, areas of deeper water and drying down, and decreased with altitude. The level of prediction was weak. 4. Pond types, defined by their macrophytes, were dispersed throughout the region and interspersed so that adjacent ponds often supported different assemblages. No habitat or locale supported unique types or unusual variety. 5. Local, anecdotal classifications of pond types in Northumberland, e.g. ‘subsidence ponds’, proved unreliable. Classification of ponds using macrophytes suggested greater biodisparity than such simplistic categories. The two main approaches to pond assessment (spatial surveys and ecological classification) need to be combined for sound assessment of the local status of ponds. This would benefit regional selection of pond types for conservation. © 1998 John Wiley & Sons, Ltd.  相似文献   

9.
10.
  • 1. In this work, carried out in the province of Murcia, a representative semi‐arid area of the Iberian Peninsula, water beetles were used as indicators to identify the aquatic ecosystems with the highest interest for conservation. For that purpose, an iterative algorithm of complementarity based on the richness of aquatic Coleoptera was applied. ‘Complementarity’ refers to the degree to which an area, or set of areas, contributes otherwise unrepresented attributes to a set of areas. This principle was used to maximize the number of species represented within a given number of areas.
  • 2. Only the species subsets whose taxonomic status, presence and distribution in the study area are well known were used. In total, 146 species were included, of which 12 are Iberian endemics and 32 are rare species (found only in one grid cell in the study area).
  • 3. The highest correlation was generally shown by species richness with endemic, rare and vulnerable species richness. Thus, basing conservation strategies on species richness appears to be an effective protocol.
  • 4. To preserve the highest degree of biodiversity in the aquatic ecosystems of the study area, the following need to be protected: (a) headwater streams in the north west of the province; (b) the uppermost reaches of the Segura River; (c) hypersaline and coastal ramblas; (d) rock pools and coastal ponds.
  • 5. The present network of Protected Natural Spaces in the study area does not include many of the aquatic ecosystems shown to have the highest biodiversity of beetles. However, the future European ‘Natura 2000’ network will protect the 10 grid cells of highest aquatic biodiverstity, or at least part of them.
Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

11.
  1. Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential.
  2. The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation.
  3. The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed.
  4. Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers.
  5. Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.
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12.
  • 1. Changes in agricultural activities in the Trubia valley (North Iberia, south Europe), mainly substituting husbandry by rural tourism, are modifying trough function: from cattle watering to abandonment or transformation into decorative elements. In the valley, natural ponds are disappearing by desiccation and are scarce or absent.
  • 2. In the present troughs, constructed by artificial deviation of small streams or fountains, eight amphibian species have been found, representing 57% of the amphibian species recorded in the region. Seven of them were in larval development stages.
  • 3. Moderate management, presence of sediments in the bottom and abundant floating vegetation were identified as the main factors contributing to amphibian species richness. Trough management significantly correlated with species richness and also with the presence and the genetic population variation of the model species Lissotriton helveticus (palmate newt). Most amphibian species cannot develop in excessively cleaned troughs devoid of vegetation and invertebrates.
  • 4. In the absence or decline of natural ponds and other water points, traditional troughs can be considered refuges for amphibians. Traditional management actions such as moderate cleaning and protecting vegetation and bottom sediments from these freshwater points are recommended. Promoting the traditional management of troughs is easy and, together with the protection of natural ponds, can help to prevent the decline of amphibian species. Copyright © 2010 John Wiley & Sons, Ltd.
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13.
过鱼对象的确定对于过鱼设施建设至关重要。量化评定过鱼对象优先保护次序,为南渡江过鱼设施建设、鱼类保护提供决策依据。基于过鱼设施建设目的及过坝鱼类的生境适宜能力,从过坝需求度、生境适应度、资源丰富度、物种效用度、物种濒危度和遗传损失度等6个维度,建立多指标量化的过鱼对象选择体系。采用主客观结合的组合权重,构建基于逼近理想排序法的过坝鱼类优先等级评定模型。以南渡江流域为实例进行初步分析,结合南渡江流域梯级建设,运用过鱼对象评定体系确定花鳗鲡、鲢、鳙等洄游性鱼类为首要过鱼对象,?、月鳢、鲇、海南长臀鮠为主要过鱼对象;乌塘鳢、红鳍原鲌、赤眼鳟、蒙古鲌为次要过鱼对象;鲮、倒刺鲃、马口鱼、纹唇鱼、唇?、翘嘴鲌、东方墨头鱼等鱼类为兼顾过鱼对象。本研究通过构建科学合理的多指标体系对南渡江流域过鱼设施过鱼对象优先保护次序进行量化,有助于指导过鱼设施效果评价,对过鱼设施建设具有一定参考价值。  相似文献   

14.
1. To aid in their conservation, unionid mussel assemblages were surveyed in three relatively unstudied rivers in south‐eastern Louisiana. 2. Although total species richness varied among rivers, species diversity (as estimated both by Shannon‐Weaver H′ and rank‐abundance curves) was fairly similar. 3. Assemblage composition varied among the rivers, with the West Pearl River having the most dissimilar group of species. The endangered inflated heel splitter, Potamilus inflatus, was found only in the lower Amite River. 4. The most common species had size distributions skewed towards larger individuals, but small individuals were collected (including the inflated heel splitter), indicating successful recruitment. 5. Mussels were more common in silt than in sand or gravel, perhaps because fine sediments are more stable through time in these river systems. 6. The greatest threat to these assemblages is gravel mining in the upper reaches of the rivers. At the present time only rivers with endangered species, or that have been declared scenic rivers, have any protection from gravel mining. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

15.
  1. This article highlights the practical impact of our 2018 Aquatic Conservation: Marine and Freshwater Ecosystems publication, ‘Importance of peripheral basins: Implications for the conservation of fish assemblages’, which described fish communities in a Polish river.
  2. Data on the fish assemblages of the Dniester River (Black Sea basin) are scarce; however, evidence indicates that the assemblages have declined. In our 2018 study, we hypothesized that the peripheral basin (the small basin on the edge) of the larger Upper Dniester River basin (the Strwi?? River) could maintain good ecological status and contained unique fish assemblages.
  3. To examine the influence of historical factors and assess the role of peripheral basins on fish conservation, data from the Strwi?? basin were compared with the adjacent but unconnected Wiar basin (the Vistula basin; Baltic Sea basin). The Strwi?? River fish assemblages featured higher species richness and a greater number of native Ponto–Caspian species that function near the edge of their ranges.
  4. This article focuses on four impacts of the 2018 publication: increasing awareness by various groups and organizations of the unique character of the surveyed river basin; highlighting important issues in assessing the ecological status of European rivers; driving the red‐listing of species and the development of stream fish conservation strategies; and identifying possible future impacts.
  5. Our 2018 publication demonstrated the value of studying peripheral basins, which may affect conservation strategy development and encourage study of the importance of other peripheral basins and their role in aquatic resources conservation. Our article influenced the interpretation of fish‐based biotic indices and the conduct of monitoring work and its evaluation. It also strongly emphasized the native origin of the racer goby (Babka gymnotrachelus) in the Strwi?? River, which was important for subsequent works seeking to change the legal status of the species in Poland.
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16.
  • 1. Marine life in offshore regions has not been fully censused, yet related conservation policy relies on our ability to identify areas of high biodiversity.
  • 2. We assessed the census of marine finfish on the Scotian Shelf, Northwest Atlantic using data collected during annual research vessel surveys between 1970 and 2000. The species accumulation curve did not reach an asymptote reflecting that new species continued to be discovered throughout the survey period. Only 0.12% of the area of the Scotian Shelf has been sampled since 1970.
  • 3. Since 1974, when over 50% of the species had been discovered, the community composition has been relatively constant. However, the dominance structure has changed dramatically as reflected in the geographic contraction of the formerly abundant, large‐bodied piscivores concomitant with the geographic expansion of their prey species.
  • 4. The region is under‐sampled, and species' distribution and abundance are changing. A precise estimate of diversity is elusive. As an alternative, we searched for physical correlates of finfish diversity to identify its possible surrogates. Surrogates have potential both as a method for understanding process and as a tool for conservation management. We examined the effect of area and depth range on species richness. High species richness was associated with larger areas and greater depth range at large spatial scales.
  • 5. Highly diverse areas include the Bay of Fundy, the Eastern Gully, the slopes, Western Bank and the northeastern shelf. Until now, the northeastern shelf has been under‐appreciated as a highly diverse area. Such information will be important for environmental impact assessments as well as selection of ‘sensitive’ or protected areas.
Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

17.
  1. Species of conservation concern are usually considered important elements in site prioritization for biodiversity conservation. To overcome the lack of information on species conservation status, multidimensional measures of species rarity can be used as proxies of species vulnerability.
  2. Under this assumption, a two‐step protocol for site prioritization of aquatic groundwater‐dependent ecosystems is proposed using invertebrate vulnerability estimated from species' traits. In the first step, each species occurring in the sites of interest are scored according to their vulnerability. In the second step, sites are prioritized using species' scores.
  3. Species vulnerability scores are based on five dimensions, for which various traits are scored: (i) geography, (ii) ecology, (iii) biology, (iv) population, and (v) evolutionary history. For each species, the scores of the various traits belonging to the same dimension are multiplied to obtain a synthetic score. These scores are then ranked into four classes and, for each dimension, each species receives a new score that reflects its rank. The sum of these scores represents the species' overall score.
  4. Site conservation priorities are assessed by combining species scores into three indices: Sum of Species Scores, Biodiversity Conservation Concern (which relates the sum of species scores with the local species richness) and Groundwater Biodiversity Concern (which is the average of the former two). The protocol is illustrated using case studies in Italy and it is fully implemented in the software AQUALIFE which is freely available at: http://app.aqualifeproject.eu by registered users.
  5. Sensitivity analyses showed that the protocol is robust against the lack of information on species biology or sampling limitations. However, trait scoring rests with the user, who must be familiar with the study group.
  6. This approach can be applied at any spatial scale and to different types of aquatic groundwater‐dependent ecosystems.
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18.
  • 1. The lack of information about marine biodiversity is problematic for the selection of conservation reserves that aim to protect representative samples of biodiversity. A number of surrogate measures for biodiversity have been suggested as a potential solution to this problem.
  • 2. The present study tested the effectiveness of using higher taxa of macroinvertebrates as a surrogate for species‐level identification to depict spatial variation in species richness and assemblage variation and to select conservation reserves in one estuary in south‐east Australia.
  • 3. Spatial patterns of richness and assemblage variation for species were significantly correlated with patterns defined from genera, families, orders, classes, and phyla with a decline in the magnitude of correlation coefficients from finer to coarser resolutions. A network of reserves selected to include representatives of all phyla, classes, orders, families and genera coincidentally included 54%, 61.7%, 75%, 92.6%, 98.8% species in 8.3%, 13.9%, 17.7%, 44.4% and 58.3% of grid cells, respectively. However, only reserves selected for genera, families and orders performed significantly better than random selection.
  • 4. Percentage of species represented by orders, families and genera in a realistic level of available grid cells for conservation (i.e. 13.9%) were very close ranging between 70 and 73.5%. A factor diminishing the performance of order as surrogate for species richness was related to the difficulty of identifying many macroinvertebrates to the order level. Therefore, it is concluded that genus‐ and family‐level identification is an effective surrogate for species‐level identification for conservation planning in estuaries.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

19.
Odonate larvae are important components of aquatic environments in tropical areas. They also develop in aquaculture ponds, where they can cause economic losses. In this study, we have tried to describe the general community patterns in aquaculture ponds in Viçosa, south-eastern Brazil. Our aim is to evaluate how environmental and bionomic factors can determine their composition and species richness. We identified two groups of species (plants and bottom-dwellers) based on larval microhabitat preferences. Vegetation determines the occurrence of some species whose adults select certain plants for oviposition. The ponds with more extreme conditions (extensive cover of plants or vegetation absent) showed lower species richness than those with intermediate conditions. Coryphaeshna adnexa and Brachmesia furcata were of larger size but had low abundance or were only collected accidentally. Species of intermediate size (Tramea cophysa, Micrathyria spp., Orthemis discolor and Erytrodiplax fusca) were more abundant and are considered as potential predators of fish fry.  相似文献   

20.
Pires DF, Pires AM, Collares-Pereira MJ, Magalhães MF. Variation in fish assemblages across dry-season pools in a Mediterranean stream: effects of pool morphology, physicochemical factors and spatial context. Ecology of Freshwater Fish 2010: 19: 74–86. © 2009 John Wiley & Sons A/S
Abstract –  Knowledge of patterns of refuge use by fish is critical for maintaining biodiversity in drought-prone streams. In this study, the fish assemblages of 21 dry-season pools in a Mediterranean stream were characterised and related to three sets of factors reflecting pool morphology, physicochemistry and spatial context. Fish were associated with the three sets of variables, with variation partitioning indicating that overall species richness and abundance were primarily related to pool morphology but relative species abundances were mainly associated with physicochemical contexts. In general, species richness was the highest but overall fish abundance was the lowest in large pools. Pools well shaded by riparian canopy held the highest richness and abundance of native fish, but relative species abundances and assembly structure varied among pools contingent on canopy cover, substrate composition and spatial location. These results suggested that conservation of fish diversity in Mediterranean streams requires networks of pools with diverse sizes and physicochemical contexts.  相似文献   

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