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1.
  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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2.
  1. Small wetlands are considered a refuge for biodiversity, but the importance of natural and man‐made lentic wetlands for the maintenance of bird diversity in human‐dominated landscapes is not well‐known in the Neotropics.
  2. This study evaluated the influence of the types and origins (natural or man‐made) of lentic wetlands on bird diversity of three guilds (aquatic, semi‐aquatic and landbirds) in the Meta Piedmont, Colombia.
  3. The species richness and the structure and composition of each bird guild were estimated and compared between and within wetland types (swamps, heronries, rice fields, semi‐natural lakes, constructed lakes and fish farms) and origins (natural, mixed and artificial).
  4. In total, 275 bird species were recorded (196 landbirds, 60 aquatic birds and 19 semi‐aquatic birds). Local species richness had a wide variation (39 to 144 species), and total and mean richness were significantly different between among wetland types and origins. Semi‐natural lakes were the most diverse wetland type, and heronries were the least diverse. Mixed‐origin wetlands had the highest species richness. The cattle egret (Bubulcus ibis) was the most abundant species, while heronries and rice fields showed the greatest total bird abundance.
  5. Bird diversity is strongly related to type and origin of wetlands, with significant variations in species composition among different types, which show high local and landscape heterogeneity.
  6. It is suggested that small lentic wetlands, whether natural, mixed or artificial, are important for the maintenance of local and regional bird diversity. Conservation and management actions are required to preserve wetland heterogeneity and the birds associated with it.
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3.
  1. Fish introductions into originally fishless mountain lentic habitats can affect native amphibians at different spatial scales. Introductions are often associated with local extinctions, but they can also affect amphibian metapopulations at a landscape level, intercepting amphibians when they move into reproductive and overwintering sites, preventing these movements, or reducing the overall metapopulation abundance and diversity.
  2. Freshwater habitat networks are considered more resistant to biological invasions than isolated habitats, because they usually provide safe alternative sites that can buffer the impact of introduced fish. However, few studies have attempted to understand whether fish stocking also affects amphibians in surrounding fishless habitats.
  3. This general hypothesis was tested using distribution data of Italian crested newt (Triturus carnifex Laurenti 1768) in a mountain pond network collected over a 13‐year‐long study (2005–2017), encompassing the periods before (pre‐2011) and after (post‐2012) fish (Salmo trutta L. 1758) were introduced in the pond where most of the newts were initially observed.
  4. After fish introduction, visual counts dropped down close to zero in the invaded pond, but they increased in satellite ponds. This was a progressive increase not related to population size and should be regarded as a short‐term consequence of the slow colonization of satellite ponds.
  5. These results confirm the dramatic impact of fish introductions on native amphibians at a local scale, but suggest that some amphibians can counteract their impact by moving to alternative sites, when available.
  6. Halting fish stocking, lake and pond recovery, and the construction of alternative sites are proposed as management and conservation actions to preserve amphibian diversity.
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4.
  1. Stream fish diversity is threatened by anthropogenic environmental alterations to landscapes, and successful conservation requires knowledge of the processes that degrade diversity. A primary step in identifying diversity losses is the comparison between historical and contemporary states of landscapes and fish assemblages, but uncertainty remains regarding the appropriate spatial scales of investigation.
  2. Historical data collected in 1976 were paired with two years of contemporary replication (2015, 2016) to assess fish diversity change at 10 sites in Blackburn Fork, TN, USA. Analyses focused on a nested hierarchy of spatial scales, including sampling sites (fine scale), nested within stream orders (intermediate scale), nested within the entire catchment (broad scale). Diversity change between 1976 and 2015–16 was assessed using traditional diversity metrics (site scale) and rarefaction (stream‐order scale), whereas spatial variation in contemporary diversity (2015–16) was assessed with nonmetric multidimensional scaling (catchment scale).
  3. At the site scale, locations on the east side of Blackburn Fork and in close proximity to developed land experienced diversity loss. At the stream‐order scale, the effective number of species declined in first‐order streams where land development was concentrated, but no consistent species losses occurred in other stream orders. At the catchment scale, assemblages responded significantly to stream size but not land use, perhaps because diversity was already homogenized by 2015–16. Mapping 40 years of land‐use change across the catchment underscored a pattern of spatial alignment between developed lands and stream fish diversity loss.
  4. This study highlights the benefits of considering multiple spatial scales when assessing historical change in stream fish assemblages, and highlights stronger inference derived from historical comparisons relative to contemporary space‐for‐time substitutions. This framework combines recent analytical advances in rarefaction with a riverscape perspective, and can be applied to conserve streams, and their biota, in riverscapes around the world.
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5.
6.
  1. Global environmental change is threatening freshwater biodiversity with ecological impacts predicted to be particularly severe in high-altitude regions. Despite this, an ecological understanding of high-altitude pond networks remains patchy, with only limited knowledge of the environmental and spatial predictors of taxonomic and functional diversity. Moreover, previous studies of pond ecosystems have focused primarily on taxonomic richness and largely overlooked functional diversity.
  2. This study examined the influence of local environmental and spatial factors on taxonomic and functional α and β diversity (including the turnover and nestedness-resultant components) of 17 high-altitude (~2,500 m above sea level) pond macroinvertebrate communities, in the Macun Cirque, Switzerland.
  3. Spatial processes (pond connectivity) were important drivers for taxonomic α diversity, while local environmental variables (pond permanence and surface area) were important determinants of functional α diversity. Species turnover was the most important component of β diversity for taxonomic composition, and functional composition demonstrated a nested spatial pattern.
  4. Variation in taxonomic and functional composition (and the turnover and nestedness components of β diversity) were determined by local environmental variables despite the limited environmental gradients within the pond network. No significant effects of spatial variables on community composition were recorded for either facet of diversity, indicating that compositional variation was determined at a local scale. Water temperature, depth and pond permanence were consistently the most important measured drivers of diversity.
  5. Given the importance of both spatial and environmental variables in structuring taxonomic and functional diversity, landscape-scale conservation and management activities that aim to improve or protect high-altitude freshwater biodiversity should focus on maintaining connectivity among ponds and environmental heterogeneity, particularly pond surface area, water depth, and hydroperiod. Understanding the mechanisms driving taxonomic and functional diversity will be critically important for the management and conservation of macroinvertebrate communities in high-altitude pond networks in the face of climatic warming.
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7.
  • 1. Rice field expansion is one of the activities associated with the disappearance of 90% of the wetlands in southern Brazil. Worldwide, rice agriculture has been recognized as having considerable potential value for many aquatic species. Nevertheless, management practices in such systems must be ameliorated and better investigated.
  • 2. This study evaluated the potential role of rice fields as refugia for amphibians, and whether different hydrologic management practices after rice cultivation could contribute to wetland amphibian conservation in southern Brazil.
  • 3. Six collections were made in six rice fields with different management practices after cultivation (three dry and three flooded) and three natural wetlands. The amphibians were sampled through six random 15‐min visual transects per collection in each rice field and the natural wetlands.
  • 4. In total, 2139 anuran individuals were observed in rice fields (798) and Reserva Lake (1341), comprising 12 anuran species distributed among five anuran families. Anuran richness and abundance varied over the rice cultivating cycle, and they were higher in the growing phases than in the fallow phases. The mean anuran richness and abundance was higher in Reserva Lake than in flooded and dry rice fields.
  • 5. The different management practices adopted after the harvesting period (presence or lack of surface water) did not influence the anuran richness and abundance. It did, however, influence species composition.
  • 6. The difference in species composition between the management practices adopted is an interesting result in terms of biodiversity conservation. Rice producers could maintain part of their agricultural land flooded during the fallow phase as a strategy to preserve a higher diversity of anurans. These results should be taken into consideration in wetland conservation plans in southern Brazil; however, the percentage of each agricultural land that should be kept flooded should be decided by Brazilian agricultural and conservation policies. Such a strategy would reconcile agricultural/economic needs with the conservation of biodiversity in southern Brazil, where more than 90% of wetland systems have already been lost. Copyright © 2009 John Wiley & Sons, Ltd.
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8.
  1. Farmland ponds promote regional aquatic biodiversity; however, optimally managing these ponds requires knowledge on how the biodiversity differs between ponds across catchments with different land uses.
  2. This study investigated the response of macrophytes, both those in the pond and on the bank, as well as dragonfly and water beetle species richness, diversity and composition in artificial ponds, to numerous environmental variables in catchments dominated by three land uses: protected areas (as reference sites), sugarcane‐dominated and forestry‐dominated landscapes, across two seasons.
  3. There was a strong association between insect species richness and vegetation cover, particularly sedges (Cyperus spp.) in spring and bulrushes (Typha capensis) in summer. There was also a positive response between insect species richness and sedges up to 70% cover, and bulrushes up to 40% cover, after which there was a decrease. Furthermore, the protected area ponds contained more rare and specialist insect species. Pond size was not a major variable for biodiversity overall.
  4. Although there was generally little congruence in composition among the three taxa, dragonflies were a good surrogate for water beetles and floating macrophytes.
  5. Well‐vegetated ponds, both in the water and along the margin, are the most suited to promoting biodiversity, as long as the vegetation is not too dense, and not dominated by one plant species.
  6. Artificial ponds in production landscapes have great potential for conserving aquatic species, irrespective of land use, as long as there is management for macrophyte density and heterogeneity.
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9.
  1. Amphibians are the vertebrate group experiencing the steepest global population decline and species loss. Habitat alteration and loss caused by the intensification of agriculture is among the main causes; however, in the past, amphibians have been favoured by traditional agriculture and husbandry as more terrestrial and aquatic habitats became available through land‐use diversification and the construction of artificial facilities for cattle watering. Troughs for cattle watering may represent the only permanent water points for amphibian reproduction in human‐modified landscapes.
  2. The present study focused on Lissotriton vulgaris meridionalis, a semi‐aquatic salamander, subendemic and widespread in Italy, capable of colonizing artificial aquatic habitats. The main goal was to determine the importance of drinking troughs for the ecology and conservation of the species in a hilly area (Latium region, Central Italy) subjected to traditional livestock farming (i.e. Maremmana cattle).
  3. Specifically, generalized linear models (GLMs) were used to analyse the effects of drinking trough characteristics (i.e. size, substrate, aquatic vegetation), landscape features (distance to the forest, forest cover, percentage of cultivated lands and infrastructural development, terrestrial connectivity) and intensity of management practices on the occurrence and abundance of the target species.
  4. In the light of the present results, it is suggested that drinking troughs represent suitable surrogates for pristine habitats for L. vulgaris meridionalis. Hence, even man‐made aquatic habitats, associated with traditional husbandry, may help to sustain amphibian populations in landscapes where natural wetlands are scarce. The present findings are timely because of the lack of empirical data on the role of drinking troughs in amphibian conservation within rural socio‐economic scenarios, which may have been neglected in research and policy in favour of lakes, rivers and streams.
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10.
  1. Debate surrounds the best way to deal with pond terrestrialization so as to maximize landscape‐scale biodiversity. One way of addressing this issue is to re‐set succession via management activities, but the merits of this approach relative to non‐intervention and pond creation are little known.
  2. Manor Farm in Norfolk, UK, possesses around 40 ponds, and each year three to four ponds are subject to management involving tree (de‐shading) and/or sediment removal. To determine the consequences of management for pond biodiversity, macrophyte and invertebrate communities were surveyed for replicate ponds covering four ‘time since management’ categories: no management, and managed over the periods 1999–2003, 2004–2006 and 2007–2009.
  3. Macrophyte diversity was significantly lower in unmanaged ponds compared with ponds managed in 2004–2006 and 2007–2009. In addition, with the exception of Mollusca, invertebrate diversity was significantly lower in the unmanaged ponds compared with all the managed ponds. A tendency was evident for diversity to peak 3–5 years after management and for a subsequent decline in diversity (significant for macrophytes). No distinctive species assemblages were associated with the different pond successional stages, although several species were confined to individual ponds. Although many species were absent from the non‐managed ponds, especially in the macrophytes and Coleoptera, few species were unique to these ponds.
  4. The principal driver of species turnover in the ponds was shade, which was negatively correlated with macrophyte cover. Shade was substantially higher in the unmanaged ponds, whose species‐poor assemblages appeared to be a consequence of low oxygen levels. By arresting succession and restoring macrophyte‐dominated early‐ and mid‐successional ponds, management may have an essential role in biodiversity conservation. In pond‐rich landscapes, where a high proportion of ponds are heavily terrestrialized, management provides a sustainable means both of preserving heterogeneity in the pond network and preventing the loss of large numbers of species which favour early‐ and mid‐successional ponds. Copyright © 2012 John Wiley & Sons, Ltd.
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