Contrasting effects of mass-flowering crops on bee pollination of hedge plants at different spatial and temporal scales

Landscape-wide mass-flowering of oilseed rape (canola Brassica napus) can considerably affect wild bee communities and pollination success of wild plants. We aimed to assess the impact of oilseed rape on the pollination of wild plants and bee abundance during and after oilseed-rape bloom, including effects on crop-noncrop spillover at landscape and adjacent-field scales. We focused on two shrub species (hawthorn Crataegus spp., dog rose Rosa canina) and adjacent herb flowering in forest edges, connected hedges, and isolated hedges in Lower Saxony, Germany. We selected 35 landscape circles of 1 km radius, differing in the amount of oilseed rape; 18 were adjacent to oilseed rape and 17 to cereal fields, and we quantified bee density via pan traps at all sites. Adjacent oilseed rape positively affected fruit mass and seed number per fruit of simultaneously flowering hawthorn (no effect on dog rose, which flowers after the oilseed rape bloom). At the landscape scale, oilseed rape had a negative effect on bumble bee density in the hedges during flowering due to dilution of pollinators per unit area and the consequently intensified competition between oilseed rape and wild shrubs, but a positive effect after flowering when bees moved to the hedges, which still provided resources. In contrast, positive landscape-scale effects of oilseed rape were found throughout the season in forest edges, suggesting that edges support nesting activity and enhanced food resources. Our results show that oilseed rape effects on bee abundances and pollination success in seminatural habitats depend on the spatial and temporal scale considered and on the habitat type, the wild plant species, and the time of crop flowering. These scale-dependent positive and negative effects should be considered in evaluations of landscape-scale configuration and composition of crops. Food resources provided by mass-flowering crops should be most beneficial for landscape-wide enhancement of wild bee populations if seminatural habitats are available, providing (1) nesting resources and (2) continuous flowering resources during the season

Landscape configuration of crops and hedgerows drives local syrphid fly abundance

Summary 1. Human-dominated landscapes are characterized by a mosaic of natural and managed eco- systems, affecting arthropod communities on different spatial scales. Effective landscape man- agement for functionally important organisms suffers from little understanding of organism spillover between semi-natural habitats and adjacent crops, and of how it is affected by the surrounding landscape. 2. We examined syrphid abundance (Diptera: Syrphidae) in three types of linear semi-natural habitats, differing in connectedness to annual crops and forest [forest edges ( n = 12), forest- connected hedges ( n = 11) and isolated hedges ( n = 12)], as well as in the adjacent oilseed rape or winter wheat fields (i.e. altogether n = 70 sites in 35 landscapes). The landscape cir- cles with 1 km radius around the study sites differed in the proportion of oilseed rape (rang- ing from 0% to 35% oilseed rape) enabling us to test landscape-scale effects of oilseed rape. 3. Aphidophagous syrphids were more abundant in forest-connected hedgerows than in for- est edges (with isolated hedges being intermediate), and more abundant in crop fields adjacent to hedgerows than adjacent to forest edges, indicating spillover from semi-natural habitats to the adjacent crop fields. Aphidophagous syrphid abundance was higher in semi-natural habi- tats adjacent to oilseed rape fields than adjacent to wheat fields if the proportion of oilseed rape in the landscape was low (indicating local concentration). 4. Synthesis and applications. This study highlights the potential of hedgerows to enhance the abundances of beneficial syrphids and their spillover to adjacent crop fields, especially when they are connected with forests. We provide evidence that this local exchange is moderated by the extent of mass-flowering crops in the surrounding landscapes due to local concentration. There- fore, measurements for the improvement in local biological functioni ng should be evaluated by simultaneously investigating local and regio nal aspects of crop configurations to allow for region-specific management recommendations. Increasing the total amount of hedgerows in the agricultural matrix under moderate landscape- scale proportions of mass-flowering crops may serve best for the conservation of biodiversity and augmentation of i mportant ecosystem services such as biological control and pollination in lands capes dominated by agricultural cultivations

The Green Movement: Implications for Animals

The Green movement, a newly emerging political movement that is both global in scope and firmly anchored to each local region at the grassroots level, is destined to be of great import to those concerned with the status of nonhuman animals in our society. Closely allied with deep ecology and bioregionalism, Green thinking embodies an alteration in our perception of the human organism: no longer seen as separate from and superior to all the other components of the ecosystem, our species is placed in context as one among many interdependent forms of life, with the attainment of a sustainable balance among all life forms being the desired goal in designing our human activities. Translation of this viewpoint into political action is the challenge of Green organizations on several continents today

Local-scale attributes determine the suitability of woodland creation sites for Diptera

New native woodlands are typically created in a small and isolated configuration, potentially reducing their value as a resource for biodiversity. The use of ecological networks for habitat restoration and creation could be beneficial for woodland biodiversity. This approach is conceptualised as local and landscape-scale conservation actions to increase the area, quality, amount and connectivity of habitat types. However, there is limited evidence about the value of secondary woodlands and the relative or combined effects of network variables for woodland insects.  Seventy-eight woodland sites created in the last 160 years across England and Scotland were sampled for hoverflies (Diptera: Syrphidae) and craneflies (Diptera: Tipuloidea), using two Malaise net traps placed in the centre of each woodland. The diversity of insects supported by created woodland patches was analysed using measures of dissimilarity, and the relative direct and indirect effects of ecological network variables on their abundance and species richness were assessed using structural equation models.  We found 27% of British woodland hoverfly species and 43% of British woodland cranefly species in the study sites, indicating that woodland insects are colonising created native woodlands, despite their fragmented nature. However, these species communities were highly variable across woodland patches.  Landscape-scale variables had no effect on woodland-associated hoverflies or craneflies relative to local-scale variables. Local-scale variables relating to habitat 34 quality (i.e. structural heterogeneity of trees and understory cover) had the strongest influence on abundance and species richness.  Synthesis and applications – To benefit woodland-associated Diptera, woodland creation and restoration should maintain a focus on habitat quality. This should include active management to facilitate a diverse tree and understorey vegetation structure. Many woodlands in the UK are privately owned and landowners should be encouraged to plant and actively manage their woodlands to increase structural heterogeneity and resources for woodland insects

La expedición minera del barón de Nordenflicht y las autoridades peruanas

Traditionally, the failure of Baron Nordenflicht’s mining expedition to Peru has been attributed to the negative attitude towards the mission supposedly displayed by the Peruvian authorities in general and Viceroy Francisco Gil y Lemos (1790-1796) in particular. This article refutes this theory, proving that the failure of the expedition was the result of its own technical shortcomings and not a consequence of a supposed lack of support on the part of the authorities.Tanto los integrantes de la expedición minera del barón de Nordenflicht como la historiografía tradicional han responsabilizado al virrey Francisco Gil y Lemos (1790-1796) y a las autoridades peruanas del fracaso de la misión. Este artículo refuta documentalmente esta versión, demostrando que dicho fracaso se debió a razones técnicas y no a supuestas trabas por parte de las autoridades virreinales

Dominio y catástrofe. Los terremotos en Concepción, Chile: 1550-1751

In the Chilean city of Concepción, the catastrophes seem to appear according to human will. This was one of the conditions that the inhabitants of that place tried to impose on nature in order to overcome, architecturally talking, its orders and dynamics. Thus, this present article tries to analyze the transformation of that legendary urbe in relation to the destructive effect of earthquakes and tsunamis that affected it since its foundation to its transfer in 1751.En la ciudad chilena de Concepción, las catástrofes parecieron manifestarse según la voluntad humana. Ésta fue una de las condiciones que los habitantes de su suelo intentaron imponerle a la naturaleza para así superar, arquitectónicamente hablando, sus órdenes y dinámicas. En este contexto, el presente artículo analiza la transformación de aquella legendaria urbe con relación al efecto destructor de los terremotos y tsunamis que la afectaron desde su fundación hasta su traslado en 1751

Detecting pest control services across spatial and temporal scales

Natural habitat may deliver ecosystem services to agriculture through the provision of natural enemies of agricultural pests. Natural or non-crop habitat has strongly positive effects on natural enemies in cropland, but the resulting impact on pests is not as well established. This study measured weekly natural enemy (syrphid fly larvae) and pest (cabbage aphid) abundances in Central California broccoli fields for three years. Abundance of syrphid fly larvae increased strongly with the proportion of natural habitat surrounding the farm. As the density of syrphid fly larvae increased, weekly aphid population growth rates slowed, such that aphid densities just prior to harvest were lowest in farms with natural habitat. These landscape-mediated impacts of syrphids on aphids were not evident when data were aggregated into annual averages, a common metric in research on pest control services. We suggest that higher temporal resolution of data for natural enemy and pest abundance can reveal top-down control that is otherwise masked by seasonal and interannual variation in environmental factors. © 2013 Elsevier B.V

Opportunities to enhance pollinator biodiversity in solar parks

Renewable power capacity is increasing globally in response to energy decarbonisation, with solar photovoltaic (PV) projected to be the dominant renewable. A significant proportion of solar PV is deployed as ground-mounted solar parks with potential implications for the hosting ecosystem. Given their relatively rapid introduction, the impacts on land use and the local environment are poorly understood. However, if deployed and managed strategically, solar parks could offer unique opportunities to enhance the local environment and benefit biodiversity, with implications for ecosystem components such as pollinators. With a focus on north-west Europe, we systematically review the available evidence on how land management practices relevant to solar parks can enhance pollinator biodiversity. We assessed 185 articles for the quantity and agreement of evidence for 27 management interventions and assigned a confidence score to each finding. We show that a range of interventions applied to solar parks could increase their ability to enhance pollinator biodiversity. We then use our assessment to synthesise ten evidence-based recommendations on how to improve solar park management for pollinators by providing foraging and reproductive resources, undergoing considered management practices, increasing landscape heterogeneity and connectivity and providing microclimatic variation. Ensuring beneficial management of rapidly growing solar parks contributes to their wider environmental sustainability, with positive implications for both pollinator conservation and the energy sector in general