Farmland Ponds Research Articles

Effect of expanding farmlands with domestication of animals in the vicinity of disturbed swamps and built-up farmland ponds on population dispersion and decline of locally adapted Mansonia vectors (Diptera: Culicidae).

The adaptive processes and resilience of Mansonia vectors responsible for bioindicators can change in response to climate, land use, and environmental changes. This study evaluated the effects of expanding farmlands with the domestication of animals in the vicinity of either disturbed swamps or built-up farmland ponds on the population dispersion and decline of locally adapted Mansonia faunas as a result of expanding farmlands in Thailand. Based on environmental surveys, four different geographically defined study sites were selected: I - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying swamp with habitat fragmentation and aquatic vegetation; II - the expanding farmlands with domestication of pet animals in the vicinity of elevated swamp with habitat destruction and aquatic vegetation; III - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying farmland ponds with restoration and aquatic vegetation; and IV - the expanding farmlands with domestication of pet animals in the vicinity of elevated farmland ponds with restoration and aquatic vegetation. Human landing catch collection method was used to periodically assess the species composition and abundance of Mansonia vectors. Aggregated distributions and seasonal abundances of Mansonia faunas (Mansonia uniformis, Mansonia indiana, Mansonia annulifera, Mansonia annulata, Mansonia bonneae, and Mansonia dives) with variable proportions were observed at all the study sites. A decline in the population of Mansonia faunas, except for Ma. uniformis, was observed at study sites I and II. The anticipated effects of expanding farmlands affected the population dispersion and decline of locally adapted Mansonia faunas, thus representing a diverse assemblage of Mansonia species with different adaptations, ecological tolerances, and host exploitation strategies in life. These effects depended either on the function of disturbed swamps or on the development of farmland ponds, whether they provided a wide range of freshwater habitats, or on the domestication of animals, whether they provided animal blood meal sources.

From small waterbodies to large multi-service providers: Assessing their ecological multifunctionality for terrestrial birds in Mediterranean agroecosystems

Agricultural intensification has caused a rapid loss of singular landscape elements worldwide, such as farmland ponds, hedgerows and field margins, leading to a steep decline in farmland bird populations. Farmland ponds and traditional small waterbodies (SWB) have been recently reported to support species-rich bird communities at landscape scale in several agroecosystems. However, a comprehensive assessment on the potential ecological functions provided by SWB to terrestrial birds has been never conducted. Here, we used data from breeding bird surveys at 39 traditional SWB to highlight the variety and magnitude of ecological functions provided to terrestrial birds. These SWB belonged to three different structural types and were spread along an environmental gradient in Mediterranean agroecosystems from southeastern Spain. We identified up to six cross-system services benefiting different functional guilds of terrestrial birds. Apart from to the well-documented supply of drinking water, traditional SWB delivered other ecologically relevant and commonly overlooked services to terrestrial birds, such as the provision of bathing sites, essential food resources (e.g., emerging insects), nest-building material and suitable adjacent perches for territorial display or thermoregulation. Structural and environmental variables at waterbody scale played an important role as determinants of the recorded ecological functions. Importantly, most of these ecological functions were evenly observed across the three types of traditional SWB, thus supporting the key role of these singular landscape elements for bird conservation regardless their structural attributes. Agri-environment schemes and farmland biodiversity conservation strategies should account for the ecological multifunctionality of traditional SWB by ensuring the protection and nature-friendly management of these valuable habitats, as well as by promoting the diversity of microhabitats at SWB scale.

A moderate differential effect of organic and conventional agriculture across taxonomic groups inhabiting farmland ponds

Abstract Organic agriculture is increasingly promoted as a more environmentally friendly alternative to conventional agriculture, as it restricts the use of fertilisers and synthetic pesticides. However, the impact of both farming systems on aquatic biodiversity is strongly debated. Ponds are abundant in agricultural landscapes and strongly contribute to biodiversity. They also respond strongly to land use on a very local scale. The present study assessed the effects of conventional and organic agriculture on the taxonomic diversity of multiple groups of aquatic organisms at local and regional spatial scales. We conducted a broad scale field survey to quantify the differential impact of conventional and organic agriculture on local environmental conditions in ponds, on community composition and on local, among site and regional diversity of macrophytes, cladoceran zooplankton and selected macroinvertebrates in Belgian farmland ponds (Flanders). We observed that organic agriculture was moderately positively associated with higher local species richness for shoreline vegetation, but not for other organism groups. Only minor differences were observed for among‐pond variation, and these were mostly related to rare species of cladocerans and heteropterans. At the regional scale, ponds in organic showed higher species richness than in conventional farmland for shoreline vegetation, emergent vegetation, and cladoceran zooplankton, but lower for coleopterans and gastropods. There was no significant effect of agricultural type on water quality. We conclude that organic farming is associated with moderate positive effects on pond biodiversity and regional species richness of plants and zooplankton. We observed no systematic differences between the two types of agriculture in local environmental conditions in ponds. The absence of large differences in biodiversity and water quality between ponds located in organic and conventional farmland might be related to the dominance of intensive conventional farming in our study region and the history of conventional farming around ponds that are now surrounded by organic farming. Future studies should include other factors such as the structure of the landscape and the role of natural elements such as buffer strips surrounding the ponds.

Ratio-dependent functional response of two common Cladocera present in farmland ponds to Batrachochytrium dendrobatidis

Batrachochytrium dendrobatidis is responsible for amphibian declines worldwide. Decreasing the aquatic density of this chytrid through consumption of its infectious zoospores by Cladocera (water fleas) may mitigate the impact of chytridiomycosis. Understanding this predator-prey relationship requires insights in the zoospore ingestion rate of an average water flea, but such data are almost non-existent. We investigated the functional response of Simocephalus vetulus and Chydorus sphaericus feeding on B. dendrobatidis zoospores. These Cladocera commonly occur in farmland ponds, which may represent a major habitat for disease control. Both water fleas actively ingested zoospores and their per capita ingestion rate was best modelled in function of zoospore-to-Cladocera ratio, implying mutual interference among water fleas during zoospore feeding. The larger S. vetulus substantially consumed more zoospores, characterised by a maximum ingestion rate of 2.5 × 10 5 zoospores.Cladocera −1 .h −1 .mL −1 , which is about 12 times higher than for C. sphaericus . These findings are useful to support model-based management of chytridiomycosis. • Simocephalus vetulus and Chydorus sphaericus are common Cladocera in farmland ponds. • S. vetulus and C. sphaericus consume zoospores of B. dendrobatidis . • Zoospore ingestion rate for both Cladocera depends on zoospore-to-Cladocera ratio. • The larger S. vetulus has a significant larger per capita ingestion rate than C. sphaericus .

Improving the pollinator pantry: Restoration and management of open farmland ponds enhances the complexity of plant-pollinator networks

In line with general biodiversity losses across agricultural landscapes, insect pollinators have experienced recent sharp declines. A range of conservation measures have been developed to address these declines, with plant-pollinator interaction networks providing key insights into the effectiveness of these measures. For the first time, we studied interactions between three diurnal pollinator groups (bees, hoverflies, and butterflies) and insect-pollinated plants to understand how they are affected by pond management and restoration. Major network contributors were identified, and important network-level parameters compared at nine farmland ponds under different management strategies to assess management effects on plant-pollinator interactions: three ‘overgrown’ tree-covered ponds, three ‘long-term managed ponds’ kept in an open-canopy, early- to mid-successional state by periodic interventions involving tree and sediment removal, and three ‘recently restored ponds’, initially heavily overgrown with woody vegetation, and subsequently rapidly transformed into an early succession state through major tree and sediment removal. Interaction complexity, as measured by the metrics ‘links per species’, ‘linkage density’, Fisher’s alpha and Shannon’s Diversity, was higher for both long-term managed and recently restored ponds compared to overgrown ponds. Several network-level parameters indicated that highest complexity levels were found at recently restored ponds due to their substantially higher plant diversity. Bipartite interaction analysis suggests major benefits of pond management and restoration for agricultural pollinator assemblages. We strongly advocate the inclusion of ponds in conservation strategies and policies aimed at pollinators - ponds should be part of the pollinator pantry.

Novel Quantitative Method for Assessing Driving Forces of Landscape Succession: Case Study From Yancheng Coast, China

Variations in landscape patterns can provide key information on the effects human activity has on landscapes, and consequently, have received increased attention in recent years. This paper mainly deals with the spatio-temporal variation and driving force of the landscape pattern on the Yancheng coast using remote sensing and GIS. The results indicate the following: (1) The landscape was mostly farmland from 1984 to 2008, not wetlands. The landscape matrix changed from a situation in which the natural landscape was equal to the artificial landscape in 1984, while the latter was dominant between 1990 and 2008. The area of natural landscape decreased considerably—the proportion of natural landscapes was 51.07% in 1984, while it decreased to 28.82% in 2008. Artificial landscapes increased significantly—the majority of the increased artificial landscapes were farmland and aquaculture ponds. (2) The changes in these landscapes showed a trend, changing from natural landscapes to artificial landscapes. Salinity is the decisive factor of this fixed route o the landscape successions of the coast. (3) Although Yancheng wetland nature reserve was established in 1984 and was designated as a National Nature Reserve in 1992, anthropogenic activities on the Yancheng coast continue apace, and the trend of natural landscape loss has not changed. (4) According to the analysis of the landscape transition rate of the Yancheng coast during each phase, we concluded that the main driving force of coastal landscape succession was anthropogenic activities. Our method provides a novel quantitative method to assess the driving forces behind landscape successions.

Metadata description of the ORCA database (ORganic and Conventional Agriculture's impact on aquatic biodiversity)

The database of the ORCA project (A comparative analysis of ORganic and Conventional Agriculture's impact on aquatic biodiversity) comprises species occurrence data of different organism groups (zooplankton, macro-invertebrates, macrophytes, amphibians (eDNA) and fish (eDNA)) and data on physical, chemical and morphometric variables of 48 small farmland ponds distributed over Flanders, Belgium.

Ecoacoustics as a novel tool for assessing pond restoration success: Results of a pilot study

Abstract 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. 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. 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. 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. 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. 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.

Spatiotemporal dynamics of coastal aquaculture and driving force analysis in Southeastern China

ABSTRACT Introduction: Large-scale disordered coastal aquaculture development causes severe environmental problems. However, quantitative assessments of spatiotemporal dynamics and driving factors for coastal aquaculture are essential and urgent for coastal aquaculture sustainability.Outcomes:Using remote sensing products and geographic information science, we investigated the long-term landscape changes due to coastal aquaculture, and explored its underlying driving factors in the Ningde coastal region, Southeastern China. Results show that coastal aquaculture area increased from 90.65 km2 in 2003 to 96.08 km2 in 2016, and its structure underwent tremendous changes. The area of artificial shrimp ponds increased by 496.15% and the area of farmland ponds decreased by 25.81% between 2003 and 2016. In addition, we revealed that from 2003 to 2016, the change trends of the coastal aquaculture area and the entire Ningde coastal region were consistent, and became more fragmented and dispersive. Furthermore, regression results indicate that the growth and attenuation of coastal aquaculture areas were significantly affected by the initial coastal aquaculture area in 2003. Discussion and Conclusion:To sustainably manage the coastal ecosystems, we provide several recommendations (e.g., a coupled human and natural systems approach to understanding human-nature interactions, integrated assessment, and systematical spatial planning and monitoring) for future research and management.

Once a pond in time: employing palaeoecology to inform farmland pond restoration

The restoration of highly terrestrialized farmland ponds that combines the removal of woody vegetation and pond sediment greatly enhances aquatic biodiversity. Nonetheless, questions remain regarding the historical precedent of pond restoration, and particularly if post‐restoration aquatic macrophyte communities resemble pre‐terrestrialization assemblages. We used a paleoecological approach to address these questions for a typical, recently restored farmland pond in Norfolk, eastern England. Plant and animal remains in pond sediment cores were used to infer decadal‐centennial scale changes to pond communities and to identify past pond management events. We then evaluated the resemblance of restored and historical assemblages by comparisons with contemporary post‐restoration vegetation data. Based on changes in the abundance of terrestrial leaf remains and other indicators (increases followed by declines of aquatic organisms), the study pond appears to have a long history (going back to the early‐1800s) of canopy management (at least three inferred management events), but after the mid‐1970s, steady and substantial increases in terrestrial indicators suggest cessation of management resulting in uninterrupted terrestrialization. Aquatic macrophyte communities arising after restoration showed some similarities with historical assemblages, but also contained apparently new species. This study demonstrates how paleolimnological methods can improve understanding of pond ecological histories to better inform restoration targets and practices.

Open‐canopy ponds benefit diurnal pollinator communities in an agricultural landscape: implications for farmland pond management

Abstract Declines in pollinating invertebrates across intensively cultivated landscapes linked to reductions in flower‐rich habitats constitute a key threat to biodiversity conservation and the provision of ecosystem services. Over recent decades, many ponds in agricultural landscapes have become overgrown with woody vegetation, resulting in heavily shaded, flower‐poor pond basins and margins. Restoration of farmland ponds through removal of sediment and encroaching woody vegetation (canopy management) from pond margins greatly enhances freshwater biodiversity. Nevertheless, the consequences of pond management for pond‐margin plants and pollinating insects remain poorly understood. Here, we studied these effects for ponds in Norfolk, eastern England. We compared richness, abundance and composition of pollinating insects (hymenopterans and syrphids) and insect‐pollinated plant communities between open‐canopy pond systems subjected to either (i) long‐term regular management of woody vegetation or (ii) recent restoration by woody vegetation and sediment removal with those communities at (iii) ponds dominated by woody vegetation. Canopy management increased the richness and abundance of pollinators and insect‐pollinated plants. Pollinator richness and abundance was best explained by improvements in flower resources at open‐canopy ponds. Management most strongly influenced hymenopteran communities. Ponds represent important semi‐natural habitats for insect‐pollinated plant and pollinator communities in farmland. To enhance food resources, diversity and abundance of diurnal pollinators, conservation management at ponds should aim for mosaics of ponds at different successional stages with a high proportion of early successional open‐canopy ponds. Agricultural ponds are emerging as important habitats not only for aquatic biodiversity, but also for terrestrial species, thus warranting their prioritisation in future agri‐environment schemes.

Making an impact on UK farmland pond conservation

Abstract It is of vital importance that aquatic conservation is evidence based, and in the field of farmland pond management and restoration evidence was largely lacking until an article published in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) in 2012. To examine the influence of farmland pond management on aquatic biodiversity conservation, macrophyte and invertebrate diversity in ponds subject to traditional management involving scrub and occasional sediment removal at different time intervals in the past (0–2, 3–5, 6–10 years since management), were compared with a set of neighbouring, highly terrestrialized ponds that had not been managed for many decades. With the exception of Mollusca, significantly higher species diversity was found for managed ponds compared with the late‐succession unmanaged ponds, with invertebrate gamma diversity significantly lower for the late‐succession ponds, compared with all the managed pond categories. The AQC article was a key component of the Natural England (UK Government's adviser on the natural environment in England) ‘Freshwater and Wetland Conservation Narrative’ and has helped with integrating pond management into recent great crested newt Triturus cristatus mitigation policy as well as bringing it to the fore in past and evolving agri‐environment policy. The AQC article provided the evidence and in turn the confidence for the authors and a number of conservation partners to form a Norfolk Ponds Project. Since 2014, the Project has delivered or facilitated more than 100 pond restorations in Norfolk, eastern England, as well as educating conservation practitioners and farmers on the importance of farmland ponds via various events. With good underpinning science it has been possible to achieve considerable impact in the field of farmland pond conservation. This study shows the importance of setting aside time and support for academic staff to translate applied research outputs into practical impact.

Something is not quite right: Effects of two land uses on anuran diversity in subtropical grasslands

AbstractAlthough habitat modification is considered one of the main causes of biodiversity loss, the relative contribution of different rural land uses to biodiversity conservation is far less known. Additionally, the realization of the multidimensionality of biodiversity demands studies integrating variation of functional traits and phylogenetic information as complements to address the effects of land use on the structure of animal communities. Herein, we investigated the effects of land use (i.e., intensive agricultural and extensive livestock rearing) on functional and phylogenetic diversity of anuran communities in farmland ponds from the Uruguayan savanna ecoregion, while considering the effects of local factors (i.e., water depth) on species composition. We surveyed adults and tadpoles in 22 ponds and quantified five traits related to tadpole feeding, habitat use, and predator avoidance. Tadpole identification was corroborated by DNA barcoding based on a fragment of the mitochondrial 16S rRNA gene. We observed a decline in phylogenetic mean nearest taxon distance associated with increase of surrounding agricultural land use. While land use intensification did not affect richness (functional or phylogenetic), ponds in livestock ranches hosted about four times more tadpoles than agricultural ponds. Functional evenness decreased with water depth, although such relationship disappeared when considering phylogenetic non‐independence. Our results indicated that specific anuran clades were more sensitive to intensification in land use, reinforcing a recent view of phylogenetic homogenization following habitat conversion. Additionally, our study suggests that extensive cattle grazing over wide native pastures may provide an alternative more compatible with conservation than short‐term crops in subtropical grasslands.Abstract in Portuguese is available with online material.

Key management rules for agricultural alpine newt breeding ponds based on habitat suitability models

The alpine newt, Ichthyosaura alpestris, is very sensitive to habitat destruction and alteration which has led to declining populations across Europe. As this species is protected through the Bern Convention, it is essential to have a comprehensive understanding of its habitat requirements to ensure proper conservation measures. We trained, validated and optimized classification tree models based on data on local aquatic habitat conditions from 125 farmland ponds scattered over Belgium and Luxembourg where the alpine newt commonly occurs. To obtain user-friendly and representative models, data was pre-processed and stratified after which different degrees of pruning were applied for model optimization. In order to check the model’s applicability for management, we predicted alpine newt occurrence with an independent dataset. The most robust and reliable model revealed that fish absence was the major driving factor followed by the thickness of the sludge layer. We found that fish presence established alpine newt absence and that fishless ponds with a sludge layer of 15 cm or more were predicted to host no alpine newts. The latter provides quantitative information for decision makers. Moreover, our results indicated that the amount of sludge could be associated with eutrophication and erosion. Regarding management practices, it is advised to assure the absence of fish and reduce sludge accumulation in ponds designated for the conservation of alpine newts, for example by designing temporary ponds not fed through fish-containing surface waters. Furthermore, we recommend to install buffer strips around a pond to reduce nutrient and soil run-off from the terrestrial environment.

Ponds as insect chimneys: Restoring overgrown farmland ponds benefits birds through elevated productivity of emerging aquatic insects

Farmland bird populations have experienced severe declines across Europe and elsewhere. Agricultural intensification is believed to be a main factor behind these declines, with losses of non-cropped features, such as farmland ponds, identified as a key driver. Since the 1950s, many European farmland ponds have been in-filled or, through lack of management, become terrestrialised. Restoring terrestrialised farmland ponds has been shown to significantly increase the abundance and diversity of local farmland bird communities. It has been hypothesised that farmland birds are specifically attracted to open-canopy ponds due to increased emergent aquatic insect availability, but this link has hitherto been little explored.This study investigates how farmland pond management influences emergent aquatic insects, and how emergent insect abundance and biomass is linked to local bird assemblages. Insect emergences showed an 18-fold higher abundance and a 25-fold higher biomass at managed open-canopy ponds in comparison to their unmanaged overgrown counterparts, with day-to-day fluctuations in pond water temperature a key predictor of insect emergences. Species richness and abundance of birds at farmland ponds were strongly positively linked to the abundance of emergent insects. Furthermore, insect emergence peaks occurred on different days in different restored ponds such that the pond landscape afforded extended feeding opportunities for birds. Our findings suggest that restoring networks of terrestrialised farmland ponds to open-canopy macrophyte-dominated conditions could be a highly effective way of increasing the availability of aquatic insect prey for birds. This study highlights an urgent need to re-evaluate pond restoration and management within agri-environmental schemes in Europe and beyond.

Seasonal benefits of farmland pond management for birds

ABSTRACTCapsule: There is seasonal variation in the benefits that birds can take from restored farmland ponds.Aims: To evaluate season-specific benefits of farmland pond restoration for local bird communities.Methods: Bird communities were recorded at unmanaged overgrown and managed open-canopy farmland ponds over the breeding, post-breeding and winter seasons. Results were compared and related to seasonal variation in environmental conditions of within-pond and marginal habitats to identify predictors of local bird communities.Results: Bird communities at managed open-canopy ponds showed a higher abundance and species richness over all seasons and displayed pronounced seasonal shifts in composition. Warblers and other specialised bird species were frequently observed at open-canopy sites over the breeding and post-breeding seasons but were generally absent from overgrown ponds. While pond management and landscape connectivity had a consistent positive influence on bird communities over all seasons, the importance of other predictors such as bramble area varied seasonally.Conclusions: Our study highlights a key role of pond management for farmland bird conservation. In addition, the identified seasonal predictors of bird assemblages provide valuable lessons for the design of agri-environment prescriptions for farmland ponds, highlighting the importance of bramble-dominated patches and pond marginal habitat over the breeding season and of a strong connectivity between pond margins and surrounding semi-natural habitats throughout the year.

Species turnover drives the spatial distribution of frog beta diversity in farmland ponds

AbstractStudies integrating variation in species composition among sites are useful in understanding the impacts of land-use changes on the spatial distribution of biodiversity. However, the failure to recognize the distinction between beta diversity components, dissimilarity due to species replacement (i.e. turnover) and dissimilarity due to species loss from site to site (i.e. nestedness), can lead to inappropriate use of some indices. Here, we evaluated how the spatial distribution of anuran beta diversity components, turnover and nestedness, is associated with local and landscape descriptors in a tropical agricultural landscape with a recent history of agriculture expansion in south-eastern Brazil. Overall, 27 anuran species were found in the region with average ± SD species richness in each pool of 9.5 ± 3.5 species, ranging from 4 to 15 species. We observed that species turnover was the major component for anuran dissimilarity among pools, indicating that anuran species occurring in species-poor pools are not subsets of anuran species occurring in species-rich pools. Local variables and geographic distance were not important descriptors explaining the variation of anuran beta diversity. In contrast, the distance of the pools to the nearest forest fragment explained 16% of the variance in total beta diversity, 5% of the nestedness component and 2% of spatial turnover. Our results show that pools distributed across farmland landscapes are harbouring different anuran species composition, and together, these pools are contributing to the regional diversity of anurans in this region which is considered one of the most deforested and fragmented within Brazil.

Pond management enhances the local abundance and species richness of farmland bird communities

Agricultural intensification and the associated loss of non-cropped habitats have caused a major decline in UK farmland bird populations since the 1970s. As a consequence, there is an urgent need to implement effective conservation and habitat restoration measures in agricultural landscapes. Over the last 40–50 years, due to the cessation of traditional management practices, the majority of UK farmland ponds have become highly terrestrialised, resulting in major reductions in the diversity and abundance of aquatic plant and invertebrate assemblages. Recent research undertaken at farmland ponds in early summer, has shown restored open-canopy, macrophyte-dominated ponds support an increased abundance and diversity of farmland birds, compared to non-managed, overgrown ponds.Here, we expand on this previous research with a year-long field study to assess the implications of pond management for farmland birds by comparing bird diversity, abundance and activity at managed open-canopy ponds with those at unmanaged overgrown ponds. Driven strongly by pond management and connectivity to semi-natural landscape features such as hedgerows and woodland patches, bird abundance and species richness, as well as foraging and parental behaviour, were all significantly higher at managed open-canopy ponds. Further, a wider landscape analysis found that terrestrial land-use patterns in the vicinity of the ponds were not significant predictors of bird communities at the pond sites.In light of the numerous potential benefits to conservation-listed birds and other wildlife, we conclude that farmland pond management has been undervalued as a conservation measure to assist farmland birds. Consequently, we conclude that future agri-environment schemes, should more fully embrace farmland ponds.

Consequences of pond management for chironomid assemblages and diversity in English farmland ponds

Ponds represent a large potential resource for biodiversity in agricultural areas of lowland Europe though many are lost through natural succession towards damp woodland depressions (terrestrialisation). Managing ponds back towards their former open-water state may result in dramatic increases of biodiversity, even on heavily farmed land. Here, evidence is presented of the effects of terrestrialised farmland pond restoration on chironomid assemblages. Chironomid pupal exuviae were collected from three terrestrialised ponds on intensively-farmed land in North Norfolk, Eastern England. Two of the ponds had trees, scrub and sediment removed, while the third pond remained undisturbed as a control. Pupal exuviae collection resumed after the restoration period. In addition, nine unmanaged farm ponds and two formerly restored ponds were sampled. Nearby, another five restored ponds were also sampled for chironomid pupal exuviae. Water data revealed alkalinity, conductivity and phosphorus decreased while pH and dissolved oxygen increased after pond restoration. Chironomid species diversity, similarity and species compositional change were compared pre- and post-restoration. Assessments were made of chironomid species associated with colonisation of restored ponds as well as ponds without such management. After scrub and sediment removal the earliest colonisation of the ponds was by mud-eating species with rapid colonisation traits such as parthenogenesis, multiple generations in one year and tolerance of low oxygen conditions. Subsequent plant growth due to the opening up of the canopy led to consequent improved oxygenation and habitat structure. Other chironomid species dependent on these conditions were then able to compete with the early colonisers. Restoration also made a significant improvement in the number of chironomid species, as assessed by rarefaction curves.

Compositional and functional consequences of environmental change in Belgian farmland ponds

Abstract A resampling of 38 small farmland ponds in Belgium after 10 years revealed a high temporal species turnover for both phytoplankton and zooplankton communities, associated with substantial changes in abiotic factors, especially a reduction in total phosphorus concentration. Across ponds, phytoplankton biomass decreased while evenness and richness increased between the samplings in 2003 and 2013. By contrast, the zooplankton assemblage was characterised by lower biomass, richness and evenness in 2013. Ponds experiencing larger environmental change showed stronger changes in phytoplankton richness and evenness. Resource use efficiency (RUE) of zooplankton increased with greater environmental change and zooplankton evenness, which points to a switch towards species with higher RUE or greater variety in food sources in higher trophic levels. As ponds are important habitats for freshwater biodiversity and ecosystems services, the strong but predictable species turnover and the opposing effects of environmental change on different trophic levels need to be embedded in conservation and management plans.