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Woodcock B.A.,UK Center for Ecology and Hydrology | Bullock J.M.,UK Center for Ecology and Hydrology | McCracken M.,UK Center for Ecology and Hydrology | Chapman R.E.,UK Center for Ecology and Hydrology | And 4 more authors.
Agriculture, Ecosystems and Environment | Year: 2016

In order to make agriculture more sustainable it is important to enhance the natural processes supporting crop production, including pollination and pest control. The distance over which these services are delivered into the crop (referred to as spill-over) sets limitations on biodiversity mediated agriculture sustainability. We assess how pest control of aphids on wheat (Rhopalosiphum padi) and pollinator linked yield gain in oilseed rape decline with distance from the crop edge. For natural pest control we also assess how field margin floristic diversity (simple grass vs. species-rich wildflower) affects pest control. We do not consider the impact of field margins on oilseed rape pollination as perennial dominated field margins are not in flower at the time of oilseed rape seed set and so do not act to attract pollinators. Aphid colonies exposed to invertebrate natural enemies went extinct at a faster rate than colonies where they were excluded. The rate of decline in per capita growth rates of aphid colonies was greatest when exposed to natural predators, with this effect being detected up to 50 m into the crop where species-rich field margins were present. While oilseed rape yield gains were correlated with pollinator (bees and flies) visitation rates, there was no evidence that yield gain declined with distance from the crop edge. Possibly this was due to honeybees showing no evidence of declining visitation rates with distance into the crop (over 200 m). This contrast with bumblebees, solitary bees and flies which showed evidence of declining visitation rates with distance from the crop edge. Our results suggests that for a typical arable field (c. 12 ha) surrounded by species rich field margins, 50% of the total area could benefit from enhanced pest control services. Increased yields of oilseed rape due to insect pollinators of c. 0.4 t ha−1 were identified, but there was no evidence that field size would limit the spatial distribution of yields. Our results have implications for integrated crop management world-wide through the use of variable dose rate applications technologies that could be used to target pesticides to field centres and so help support biodiversity mediated ecosystem services. © 2016 Elsevier B.V.

Woodcock B.A.,UK Center for Ecology and Hydrology | Edwards M.,MIDHURST | Redhead J.,UK Center for Ecology and Hydrology | Meek W.R.,60 Midfield Road | And 4 more authors.
Agriculture, Ecosystems and Environment | Year: 2013

In Europe, oilseed rape is the principal crop used in the production of edible and renewable fuel oil products. Insect pollinators, in particular bees, have been shown to have a positive effect on the seed set of this crop. We undertook experiments looking at behavioural differences between honeybees, bumblebees and solitary bees visiting oilseed rape flowers, and related this to landscape scale responses in visitation rates. We found that behavioural differences between honeybees, bumblebees and solitary bees alter the likelihood of pollen transfer from their bodies to the plant stigma. Solitary bees and bumblebees tend to have greater rates of stigmal contact than honeybees. The interactions between the likelihood of free pollen on bodies and the probability of stigmal contact suggest that only 34.0% of visitations by honeybees were likely to result in pollen transfer to the stigma, relative to 35.1% for the bumblebees and 71.3% for solitary bees. Visitation rates were higher for honeybees in high quality landscapes with relatively large areas of alternative foraging habitat. Visitation rates of honeybees were also more frequent in the vicinity of managed hives. For solitary bees and bumblebees visitation rates did not respond to landscape structure, although more species of solitary bees were found in landscapes with a high cover of semi-natural grassland. While honeybees may be less efficient in pollen transfer per unit visit, where they numerically outweigh other types of bees in a crop (e.g. around managed hives) this may not be important. For this reason the relative ease with which hives can be moved across landscape means that honeybees are perhaps the most suitable taxa for use as a pro-active mitigation measure against pollinator deficits. However, the greater efficiency of solitary bees compensates for the effort required to implement longer term management (i.e. the establishment of flower rich field margins and open soil nesting sites) to support their populations. © 2013 Elsevier B.V.

Woodcock B.A.,UK Center for Ecology and Hydrology | Savage J.,UK Center for Ecology and Hydrology | Bullock J.M.,UK Center for Ecology and Hydrology | Nowakowski M.,Wildlife Farming Company | And 3 more authors.
Agriculture, Ecosystems and Environment | Year: 2013

Over three years, a replicated block design was used to investigate the effects of seed mixtures (grasses only; grasses and legumes; grasses, legumes and non-legume forbs), establishment techniques and long term management on beetle and spider communities of grassland swards. We quantified trophic links between phytophagous beetles and their host plants to assess the effect of these seed mixtures and management practices on food web structure. When managed under low intensity cutting regimes the most diverse seed mixture supported the highest biomass of beetles and spiders (c. 3.6kgha-1). Species richness of predatory beetles, phytophagous beetles and spiders were all increased by the sowing of legumes, although the addition of other forbs tended to result in at most modest further increases in invertebrate species richness. Analysis of food web structure suggests that the number of host plants utilised by beetles was greatest within the most diverse seed mixtures, but that this declined rapidly after the establishment year. We demonstrate that by sowing cheap and simple seed mixtures agriculturally improved grasslands can be managed to support increased diversity of spiders and beetles. While seed mixtures do not necessarily need to be of the highest diversity to achieve these benefits, the inclusion of legumes does appear to be crucial. The lower costs of intermediate diversity seed mixtures increase appeal to farmers, increasing the likely uptake of these methodologies in voluntary agri-environment schemes. © 2013.

Pywell R.F.,UK Center for Ecology and Hydrology | Meek W.R.,UK Center for Ecology and Hydrology | Hulmes L.,UK Center for Ecology and Hydrology | Hulmes S.,UK Center for Ecology and Hydrology | And 3 more authors.
Journal of Insect Conservation | Year: 2011

There have been serious global declines in diversity of bumblebees, butterflies and other pollinating insects. The most effective means of increasing abundance and diversity of bumblebees on farmland is to sow simple, low cost mixtures of dicotyledons rich in pollen and nectar, as prescribed under the UK agri-environment schemes. The potential benefits of this management prescription for butterflies are unknown. Similarly, more information is needed on how to manage this habitat to maximise the provision of pollen and nectar resources whilst protecting breeding habitat for butterflies. This study aimed to devise mixtures and cutting management regimes which address these issues. We found significant effects of seed mixture, timing and frequency of cutting, and removal of cut material on vegetation composition, flower resource availability and pollinators (the abundance, species richness and temporal distribution of butterflies and bumblebees, including males and queens, attracted to the mixtures). We recommend that nectar flower mixtures are refined by the inclusion of the best performing species to provide mid- and late-season forage resources (Trifolium spp., Lotus corniculatus and Centaureanigra), and the removal of competitive grass species. Summer cutting in May or early June, with removal of herbage where possible, should be applied to half the patch to extend the flowering season, and minimise damage to butterfly breeding habitat. This should be accompanied by the typical autumn cut to the whole patch. Even with best management practice, such nectar flower mixtures are only effective for 3-4 years and this should be recognised in policies aimed at enhancing pollinator populations in agricultural landscapes. © 2011 Springer Science+Business Media B.V.

Woodcock B.A.,UK Center for Ecology and Hydrology | Redhead J.,UK Center for Ecology and Hydrology | Vanbergen A.J.,UK Center for Ecology and Hydrology | Hulmes L.,UK Center for Ecology and Hydrology | And 5 more authors.
Agriculture, Ecosystems and Environment | Year: 2010

This study investigated how local habitat type and landscape structure affects the biomass, species richness and functional diversity of ground beetles sampled from a 1000. ha UK arable farm. At a local scale habitat type was either crop (winter wheat and oilseed rape) or one of five field margin habitats. Surrounding each of these sampling areas, landscape structure was defined using remote sensed data from Specim AISA Eagle (400-970. nm) and Hawk (970-2450. nm) hyperspectral sensors. Ground beetles were divided into predatory and phytophagous trophic levels. Local habitat type only affected phytophagous ground beetle biomass, which was lowest within crops. Total biomass of predatory beetles was negatively correlated, and species richness positively correlated, with landscape habitat diversity. Only the functional diversity of predatory ground beetles responded to landscape structure, showing positive correlations with the proportion of Tussock Grass field margins. Predatory ground beetles show a greater dependence on landscape structure than phytophagous species, a response that is attributed to their high mobility needed for movement between dynamically variable food resources. © 2010 Elsevier B.V.

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