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21.
During the latest decades, conservation awareness have increased and conservation of biodiversity is no longer an agenda restricted to pristine natural areas of high value but is being integrated in cultivated landscapes characterized by increasing fragmentation and anthropogenic pressures. Conservation of species has become relevant even in agricultural areas especially in countries heavily influenced by intensive farming and ubiquitous infrastructure. Based on the UN biodiversity convention all EU membership countries are obliged to develop a high nature value (HNV) farming indicator. The purpose of such an indicator is to provide a basis for informed decisions in prioritizing agricultural subsidies allocating these to high nature value areas. Here, the development of a national HNV farming indicator for Denmark is presented and its application in the Danish government-controlled agricultural subsidy system is outlined. The Danish HNV farming indicator is based on landscape structural parameters, known occurrences of natural and semi-natural habitats, current land use and the distributions of rare and threatened species. It covers all agricultural areas as well as Natura 2000 areas and nationally protected sites in Denmark, ranking them on a 0–13 point scale from low to high nature value according to their estimated value for threatened and rare biodiversity. The Danish government recognizes areas reaching at least 5 points as HNV farming areas eligible to subsidy and from 2015 and onwards the HNV farming indicator will be implemented for allocating part of the agricultural subsidies under the Rural Development Program in Denmark. The indicator will be updated annually to include the growing knowledge of species occurrence and land use changes.  相似文献   
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1. Predation on livestock is one of the main reasons for low tolerance against large carnivores in many parts of the world. Measures to reduce the conflicts have been developed, but resources for using them are often scarce. If wildlife managers as well as farmers learn more about when the risk of predation on livestock is higher, they will be able to make more effective use of resources for reducing predation.
2. In this study, we tested the hypothesis that the risk of predation on livestock immediately after an attack is higher on the affected farm compared with other farms in the same area. Data on sheep predation by brown bear Ursus arctos , lynx Lynx lynx and wolf Canis lupus in Sweden 1998–2006 were used in the analysis.
3. On depredated farms there was approximately a 55 times higher risk for a repeat predation event within 12 months compared to any other farm in the same area. During the first 5 weeks, 63%, 60% and 50% of the repeat attacks had occurred.
4. We suggest that the main mechanism behind repeat attacks on livestock is that carnivores return to the kill site to feed on carrion. Where livestock are still present and unprotected at the kill site when the carnivore returns, the farms will suffer a higher likelihood of a further attack compared to livestock on other farms. This study uses data from Sweden but we argue that the pattern will be the same in any part of the world where the ranges of livestock and large carnivores overlap.
4. Synthesis and applications . As the risk of an attack is higher directly after an initial attack, it will be more cost-effective to implement measures designed to reduce livestock predation by large carnivores at that time, i.e. within the following 5 weeks. Temporary proactive measures are usually simpler and cheaper than permanent deterrents and we recommend their use wherever resources are limited.  相似文献   
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John Clifton-Brown  Astley Hastings  Moritz von Cossel  Donal Murphy-Bokern  Jon McCalmont  Jeanette Whitaker  Efi Alexopoulou  Stefano Amaducci  Larisa Andronic  Christopher Ashman  Danny Awty-Carroll  Rakesh Bhatia  Lutz Breuer  Salvatore Cosentino  William Cracroft-Eley  Iain Donnison  Berien Elbersen  Andrea Ferrarini  Judith Ford  Jörg Greef  Julie Ingram  Iris Lewandowski  Elena Magenau  Michal Mos  Martin Petrick  Marta Pogrzeba  Paul Robson  Rebecca L. Rowe  Anatolii Sandu  Kai-Uwe Schwarz  Danilo Scordia  Jonathan Scurlock  Anita Shepherd  Judith Thornton  Luisa M. Trindade  Sylvia Vetter  Moritz Wagner  Pei-Chen Wu  Toshihiko Yamada  Andreas Kiesel 《Global Change Biology Bioenergy》2023,15(5):538-558
Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023–27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio-economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low-carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long-term, strategic R&D and education for positive environmental, economic and social sustainability impacts.  相似文献   
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1. Exchange of material across habitat boundaries is a key process in riparian zones. The movement of coarse wood from lakeshore forests to the littoral zone, where it provides habitat for aquatic organisms, is not well understood. In 2003, we resampled coarse wood within the littoral zone of four lakes in Northern Wisconsin (U.S.A.), that had originally been surveyed in 1996, to quantify the spatial arrangement of littoral coarse wood and estimate input, loss and movement rates.
2. All four lakes had a clumped pattern of littoral coarse wood, and the locations of clusters were similar in both census years. Littoral coarse wood was more abundant than expected on moderate to steep slopes, on southern shorelines, and in areas with sparse residential development.
3. All four lakes had a net accumulation of coarse wood; rates of wood input ranged from 0.5 to 1.9 logs km−1 year−1, i.e. there was more wood in 2003 than 1996. Movement rates of tagged logs varied 14-fold among lakes, with a maximum in one lake of 42% of logs recovered in 2003 more than 20 m from their 1996 location. Median distance moved ranged from 22 to 323 m among the four lakes.
4. Areas of persistently high wood density may be keystone habitats whose presence enables the persistence of populations of certain aquatic organisms. Conservation of locations with high wood density may be important to maintain target densities of coarse wood of lakes with human development.  相似文献   
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The effects that microorganisms (bacteria, viruses and fungi) have on their hosts remain unexplored for most vulture species. This is especially relevant for vultures, as their diet consists of carcasses in various stages of decomposition, which are breeding grounds for potentially pathogenic microorganisms. Here we review current knowledge of bacterial, viral and mycotic microorganisms present in wild vultures. We consider their potential to cause disease in vultures and whether this poses any population-level threats. Furthermore, we address the question of whether vultures may act as disease spreaders or mitigators. We found 76 articles concerning bacterial, viral and mycotic microorganisms present in 13 vulture species, 57 evaluating bacteria, 13 evaluating viruses and six evaluating mycotic microorganisms. These studies come from all continents where vultures are present, but mainly from Europe and North America, and the most studied species was the Griffon Vulture Gyps fulvus. We found that vultures are colonized by zoonotic pathogens, and even host-specific human pathogens. Some recorded bacteria showed multi-antibiotic resistance, especially those that can be associated with anthropogenic food subsides such as supplementary feeding stations. We found evidence that vulture health can be affected by some microorganisms, producing a wide array of clinical alterations that have the potential to influence mortality risk and fitness. We did not find clear scientific evidence that vultures play an epidemiological role spreading microorganisms to humans and other species. However, there is evidence that vultures could prevent the spread of infectious diseases through their removal of decomposing organic material. The evaluation of vulture exposure to microorganisms is of fundamental importance to design better conservation policies for this threatened group, which may serve a key role as ecosystem cleaners.  相似文献   
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Movements of prey organisms across ecosystem boundaries often subsidize consumer populations in adjacent habitats. Human disturbances such as habitat degradation or non-native species invasions may alter the characteristics or fate of these prey subsidies, but few studies have measured the direct effects of this disruption on the growth and local abundance of predators in recipient habitats. Here we present evidence, obtained from a combined experimental and comparative study in northern Japan, that an invading stream fish usurped the flux of allochthonous prey to a native fish, consequently altering the diet and reducing the growth and abundance of the native species. A large-scale field experiment showed that excluding terrestrial invertebrates that fell into the stream with a mesh greenhouse reduced terrestrial prey in diets of native Dolly Varden charr (Salvelinus malma) by 46–70%, and reduced their growth by 25% over six weeks. However, when nonnative rainbow trout (Oncorhynchus mykiss) were introduced, they monopolized these prey and caused an even greater reduction of terrestrial prey in charr diets of 82–93%, and reduced charr growth by 31% over the same period. Adding both greenhouse and rainbow trout treatments together produced similar results to adding either alone. Results from a comparative field study of six other stream sites in the region corroborated the experimental findings, showing that at invaded sites rainbow trout usurped the terrestrial prey subsidy, causing a more than 75% decrease in the biomass of terrestrial invertebrates in Dolly Varden diets and forcing them to shift their foraging to insects on the stream bottom. Moreover, at sites with even low densities of rainbow trout, biomass of Dolly Varden was more than 75% lower than at sites without rainbow trout. Disruption of resource fluxes between habitats may be a common, but unidentified, consequence of invasions, and an additional mechanism contributing to the loss of native species Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
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