188 research outputs found
Crassula invasion levels and success of recent eradication attempts at the Thompson Common pingo ponds
Crassula helmsii (New Zealand Pigmyweed) is an invasive aquatic plant in the UK
which has caused considerable damage to native aquatic plant communities in ponds
and lakes (Leach & Dawson, 1999). It is notoriously difficult to eradicate this species
and much evidence suggests that success (which is rare) requires very early
detection at the point of colonisation (Dawson, 1996; Willby, 2007)
Making an impact on UK farmland pond conservation
1.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.
2.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 (0â2, 3â5, 6â10 years since management), were compared with a set of neighbouring, highly terrestrialized ponds that had not been managed for many decades.
3.With the exception of Mollusca, significantly higher species diversity was found for managed ponds compared with the lateâsuccession unmanaged ponds, with invertebrate gamma diversity significantly lower for the lateâsuccession ponds, compared with all the managed pond categories.
4.The AQC article was a key component of the Natural England (UK Government's adviser on the natural environment in England) âFreshwater and Wetland Conservation Narrativeâ 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 agriâenvironment policy.
5.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.
6.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
Demonstrating the practical impact of publications in Aquatic Conservation â The case of crucian carp Carassius carassius in the East of England
1. The contribution of nearly three decades of research, much of it published in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC), to the conservation of the crucian carp Carassius carassius in the East of England, including work coordinated by the Norfolk Crucian Project, is summarized.
2. Although recent genetic studies indicate that this species was probably introduced to England about the same time as common carp Cyprinus carpio, the crucian carp is considered a cultural heritage species worthy of conservation in eastern England.
3. This research covers the environmental biology of the species in the East of England, documentation of the species' decline in the county of Norfolk, and the pond management practices implemented in Norfolk to rehabilitate existing and fully terrestrialized pond habitat specifically for crucian carp conservation.
4. The AQC papers that contributed to this line of research showed that England offers a particularly favourable environment for crucian carp growth and reproduction. These AQC articles provided the evidence base to complement crucian carp conservation initiatives in the London area (mainly the counties of Essex and Hertfordshire), as well as forming the basis for the designation of crucian carp as a Biodiversity Action Priority species in the county of Norfolk.
5. The broader impact of the work in the East of England was to inspire the recentlyâformed English National Crucian Conservation Project, which aims to promote the conservation of crucian carp and its habitat, and to encourage the development of wellâmanaged crucian fisheries.
6. These evidenceâbased conservation initiatives, perhaps the first throughout Europe, have witnessed a reversal of the species' fortunes in England, which is effectively an ideal geographical region in which to promote the conservation of this species within a wider, European context
Palaeolimnological evidence for eutrophication in Malham Tarn (SSSI), North Yorkshire
This is the final report to Natural England on the project âPalaeolimnological evidence for eutrophication in Malham Tarn (SSSI), North Yorkshireâ. The aim is to seek palaeolimnological evidence for
eutrophication in Malham Tarn both to complement and cross-validate contemporary and other historical
evidence for such at the site, as well as to establish whether eutrophication-related changes in the aquatic
macrophyte community occurred before the invasion of Elodea canadensis in 1962. Palaeolimnology is
also used to assess whether there is evidence for eutrophication extending back to the 18th century as
has been suggested (Pentecost, 1998; Bradley, 2007), and to aid in describing the unimpacted state of
Malham Tarn and the setting of conservation targets
How effective are plant macrofossils as a proxy for macrophyte presence? The case of Najas flexilis in Scotland
© 2017 The Author(s) Preventing biodiversity loss is a key aim of modern conservation, and paleolimnology can inform conservation strategies for target species and habitats where other data are unavailable. Care must be taken to fully understand the possibilities and limits of such techniques, particularly where they concern single species. This study uses plant and seed distribution data to inform macrofossil reconstructions of the rare macrophyte Najas flexilis (Slender Naiad) in Scotland, UK. It answers three questions: (a) How does the location of N. flexilis seeds in the surface sediments relate to the distribution of N. flexilis plants? (b) How do the numbers of seeds in surface sediments correlate with % cover of N. flexilis plants across lakes with differing N. flexilis abundances? (c) What are the implications of these findings for paleolimnology? Percentage N. flexilis cover and number of N. flexilis seeds in surface sediments were recorded at ~100 sample points at each of three sites; one where the species was abundant, one where it was occasional and one where it was extinct. At all sites, N. flexilis seeds were present in surface sediments across the entire lake. No correlation between % cover N. flexilis and the number of seeds in surface sediments was found within individual sites. The distribution of seeds in these lakes appeared to be related to multiple environmental and ecological variables including latitude and longitude (proxies for water currents). This is attributed to the ability of seed-bearing N. flexilis plants to fragment and float large distances on water. Between sites, there was a significant difference in the mean seed counts, with higher mean seed counts corresponding to higher abundances of N. flexilis plants. It is concluded that N. flexilis is likely to be well represented in sediment cores taken from any location within a basin, but that care should be taken when inferring changes in N. flexilis abundance from changes in the numbers of seeds in sediment samples. This work demonstrates that the reproductive ecology (number of seeds produced and dispersal mechanisms) is an important factor to consider when attempting reconstructions of single aquatic plant populations from macrofossil records
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 âovergrownâ tree-covered ponds, three âlong-term managed pondsâ kept in an open-canopy, early- to mid-successional state by periodic interventions involving tree and sediment removal, and three ârecently restored pondsâ, 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 âlinks per speciesâ, âlinkage densityâ, Fisherâs alpha and Shannonâs 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
Nocturnal pollinators strongly contribute to pollen transport of wild flowers in an agricultural landscape
Dramatic declines in diurnal pollinators have created great scientific interest in plantâpollinator relationships and associated pollination services. Existing literature, however, is generally focused on diurnal pollinating insect taxa, especially on Apidae (Hymenoptera) and Syrphidae (Diptera) pollinators, while nocturnal macro-moths that comprise extremely species-rich flower-visiting families have been largely neglected. Here, we report that in agricultural landscapes, macro-moths can provide unique, highly complex pollen transport links, making them vital components of overall wild plantâpollinator networks in agro-ecosystems. Pollen transport occurred more frequently on the moths' ventral thorax rather than on their mouthparts that have been traditionally targeted for pollen swabbing. Pollen transport loads suggest that nocturnal moths contribute key pollination services for several wild plant families in agricultural landscapes, in addition to providing functional resilience to diurnal networks. Severe declines in richness and abundance of settling moth populations highlight the urgent need to include them in future management and conservation strategies within agricultural landscapes
Nutrient sources to Blickling Hall Lake
Blickling Hall Lake is a relatively large (10.1 ha.) shallow (average depth 95 cm) estate lake
in the grounds of Blickling Hall, near Aylsham, North Norfolk. It was formed in the early
1700s through the damming of a small tributary of the River Bure, presently the major inflow
to the lake. Water levels in the lake are controlled by a sluice and there is one outflow which
ultimately feeds into the River Bure. The site has considerable current conservation interest
in the form of an extensive fringing reedswamp, which provides good habitat for birds and
dragonflies in particular. Currently, however the lake itself is of minimal conservation interest
Sediment accumulation in the Broads. A report to the Broads Authority
Sediment accumulation rate data are described for 15 cores from 11 sites in the Norfolk
and Suffolk Broads. Sediment dating was determined using a combination of radiometric
({210}^Pb, {137}^Cs) and spheroidal carbonaceous particle techniques. These approaches were
combined to produce a âbest available chronologyâ for each site. However, at some sites
results were still poor and the resulting data must be treated with caution
A new role for pond management in farmland bird conservation
Biodiversity declines in agricultural landscapes represent a major conservation challenge. In the UK, some agricultural landscapes contain high pond densities, but many farmland ponds have become terrestrialised since the 1960s, with input of organic material resulting in a decrease in the size and depth of ponds that eventually transform into wet woodland habitats. Pond management, including removal of overhanging scrub and sediment, has proven highly effective in enhancing freshwater biodiversity. However, the implications of this management for farmland bird assemblages are unknown. Bird surveys were undertaken at recently managed, open, macrophyte-dominated and at highly terrestrialised, macrophyte-free ponds in the intensively cultivated farmland of North Norfolk, UK. The diversity, abundance and composition of bird assemblages visiting these ponds were compared to determine responses to pond management by tree and mud removal. Avian species richness, abundance and bird-visit frequencies were all higher at open farmland ponds. The observed patterns of bird occurrence were best explained by management-induced reductions in tree shading that resulted in aquatic macrophyte-dominance likely associated with high emergent invertebrate prey abundance. Moreover, we predict that open-canopy ponds offer greater habitat heterogeneity than overgrown ponds, allowing diversified bird use. Overgrown, terrestrialised ponds were preferred by some woodland bird species. Gamma diversity across the entire pondscape exceeded all individual pond alpha diversity measures by an order of magnitude, suggesting distinct variation in the bird assemblages visiting farmland ponds during different successional stages. Pond management that generates a mosaic of pond successional stages, including open-canopy, macrophyte-dominated ponds, could help to address the long-term decline of farmland birds. We strongly advocate increased agro-ecological research in this field, combined with greater emphasis on ponds and pond management options in agri-environment schemes
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