Suchergebnisse

Insect populations decline, particularly in intensively managed agricultural landscapes. Insect communities are influenced by current agricultural practices, which are themselves determined by the economic, political and social frameworks. We highlight these direct and indirect drivers affecting insect communities, raise key research questions and discuss options for action to encourage a transformative change towards an economic, political and social system protecting biodiversity. ; peerReviewed

Insect populations decline, particularly in intensively managed agricultural landscapes. Insect communities are influenced by current agricultural practices, which are themselves determined by the economic, political and social frameworks. We highlight these direct and indirect drivers affecting insect communities, raise key research questions and discuss options for action to encourage a transformative change towards an economic, political and social system protecting biodiversity.

Abstract: Biodiversity–ecosystem functioning (BEF) research has extended its scope from communities that are short‐lived or reshape their structure annually to structurally complex forest ecosystems. The establishment of tree diversity experiments poses specific methodological challenges for assessing the multiple functions provided by forest ecosystems. In particular, methodological inconsistencies and nonstandardized protocols impede the analysis of multifunctionality within, and comparability across the increasing number of tree diversity experiments. By providing an overview on key methods currently applied in one of the largest forest biodiversity experiments, we show how methods differing in scale and simplicity can be combined to retrieve consistent data allowing novel insights into forest ecosystem functioning. Furthermore, we discuss and develop recommendations for the integration and transferability of diverse methodical approaches to present and future forest biodiversity experiments. We identified four principles that should guide basic decisions concerning method selection for tree diversity experiments and forest BEF research: (1) method selection should be directed toward maximizing data density to increase the number of measured variables in each plot. (2) Methods should cover all relevant scales of the experiment to consider scale dependencies of biodiversity effects. (3) The same variable should be evaluated with the same method across space and time for adequate larger‐scale and longer‐time data analysis and to reduce errors due to changing measurement protocols. (4) Standardized, practical and rapid methods for assessing biodiversity and ecosystem functions should be promoted to increase comparability among forest BEF experiments. We demonstrate that currently available methods provide us with a sophisticated toolbox to improve a synergistic understanding of forest multifunctionality. However, these methods require further adjustment to the specific requirements of structurally complex and long‐lived forest ecosystems. By applying methods connecting relevant scales, trophic levels, and above‐ and belowground ecosystem compartments, knowledge gain from large tree diversity experiments can be optimized

Abstract: Plant diversity begets diversity at other trophic levels. While species richness is the most commonly used measure for plant diversity, the number of evolutionary lineages (i.e. phylogenetic diversity) could theoretically have a stronger influence on the community structure of co‐occurring organisms. However, this prediction has only rarely been tested in complex real‐world ecosystems.Using a comprehensive multitrophic dataset of arthropods and fungi from a species‐rich subtropical forest, we tested whether tree species richness or tree phylogenetic diversity relates to the diversity and composition of organisms.We show that tree phylogenetic diversity but not tree species richness determines arthropod and fungi community composition across trophic levels and increases the diversity of predatory arthropods but decreases herbivorous arthropod diversity. The effect of tree phylogenetic diversity was not mediated by changed abundances of associated organisms, indicating that evolutionarily more diverse plant communities increase niche opportunities (resource diversity) but not necessarily niche amplitudes (resource amount).Our findings suggest that plant evolutionary relatedness structures multitrophic communities in the studied species‐rich forests and possibly other ecosystems at large. As global change non‐randomly threatens phylogenetically distinct plant species, far‐reaching consequences on associated communities are expected

Reversing the decline of biodiversity in European agricultural landscapes is urgent. We suggest eight measures addressing politics, economics, and civil society to instigate transformative changes in agricultural landscapes. We emphasize the need for a well-informed society and political measures promoting sustainable farming by combining food production and biodiversity conservation

1. Pollination by insects is a key input into many crops, with managed honeybees often being hired to support pollination services. Despite substantial research into pollination management, no European studies have yet explored how and why farmers managed pollination services and few have explored why beekeepers use certain crops. 2. Using paired surveys of beekeepers and farmers in 10 European countries, this study examines beekeeper and farmer perceptions and motivations surrounding crop pollination. 3. Almost half of the farmers surveyed believed they had pollination service deficits in one or more of their crops. 4. Less than a third of farmers hired managed pollinators; however, most undertook at least one form of agri‐environment management known to benefit pollinators, although few did so to promote pollinators. 5. Beekeepers were ambivalent towards many mass‐flowering crops, with some beekeepers using crops for their honey that other beekeepers avoid because of perceived pesticide risks. 6. The findings highlight a number of largely overlooked knowledge gaps that will affect knowledge exchange and co‐operation between the two groups. ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Grant/Award Number: 841.11.001; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, Grant/Award Number: 43001; Natural Environment Research Council, Grant/Award Number: NE/K015419/1 and NE/N014472/1; Javna Agencija za Raziskovalno Dejavnost RS, Grant/Award Number: V4‐1622 and P1‐0255; Rural and Environment Science and Analytical Services Division; Bayer Crop Science; European Cooperation in Science and Technology, Grant/Award Number: oc‐2013‐1‐15320; BBSRC, Grant/ Award Number: BB/R00580X/1; The Scottish Government Rural Affairs and the Environment Strategic Research Programme ; info:eu-repo/semantics/publishedVersion

1. Pollination by insects is a key input into many crops, with managed honeybees often being hired to support pollination services. Despite substantial research into pollination management, no European studies have yet explored how and why farmers managed pollination services and few have explored why beekeepers use certain crops. 2. Using paired surveys of beekeepers and farmers in 10 European countries, this study examines beekeeper and farmer perceptions and motivations surrounding crop pollination. 3. Almost half of the farmers surveyed believed they had pollination service deficits in one or more of their crops. 4. Less than a third of farmers hired managed pollinators; however, most undertook at least one form of agri‐environment management known to benefit pollinators, although few did so to promote pollinators. 5. Beekeepers were ambivalent towards many mass‐flowering crops, with some beekeepers using crops for their honey that other beekeepers avoid because of perceived pesticide risks. 6. The findings highlight a number of largely overlooked knowledge gaps that will affect knowledge exchange and co‐operation between the two groups. ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Grant/Award Number: 841.11.001; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, Grant/Award Number: 43001; Natural Environment Research Council, Grant/Award Number: NE/K015419/1 and NE/N014472/1; Javna Agencija za Raziskovalno Dejavnost RS, Grant/Award Number: V4‐1622 and P1‐0255; Rural and Environment Science and Analytical Services Division; Bayer Crop Science; European Cooperation in Science and Technology, Grant/Award Number: oc‐2013‐1‐15320; BBSRC, Grant/ Award Number: BB/R00580X/1; The Scottish Government Rural Affairs and the Environment Strategic Research Programme ; info:eu-repo/semantics/publishedVersion

Zentrale Aussagen: - Agrarlandschaften haben neben der Sicherung der Ernährungsgrundlagen viele weitere Funktionen. Hierzu zählen Ökosystemleistungen wie Bodenfruchtbarkeit und die Filterung und Speicherung von Wasser oder die Bestäubungsleistungen von Insekten. Agrarlandschaften sind auch Kulturlandschaften und als solche zugleich Lebensraum für Tiere und Pflanzen. Die Kulturlandschaft dient nicht zuletzt auch der Erholung des Menschen. - Die biologische Vielfalt in der Agrarlandschaft in Deutschland ist, selbst in Naturschutzgebieten, bei vielen Artengruppen stark zurückgegangen. Es gibt viele wissenschaftliche Belege dafür, dass der Rückgang der biologischen Vielfalt in der Agrarlandschaft Folgen für die Funtkionsfähigkeit der Aagrrökosysteme hat. - Der Wert biologischer Vielfalt besteht nicht nur in ihrem ökonomischen Potenzial. Ökosystemleistungen, kulturelle Werte sowie die Erhaltung der Arten um ihrer selbst willen begründen eine Ethik der Bewahrung der Vielfalt, die sich nicht gegen verengte ökonomische Überlegungen aufrechnen lässt. Der Wert biologischer Vielfalt in der Agrarlandschaft ist im Kontext der mannigfaltigen Leistungen der Agrarlandschaft und der daraus resultierenden Zielkonflikte zu betrachten. - Die Ursachen für den Rückgang an Tier- und Pflanzenarten liegen in einem Zusammenspiel vieler Faktoren: die Zunahme von ertragreichen, aber artenarmen Ackerbaukulturen, die vorbeugende und oft flächendeckende Nutzung von Pflanzenschutzmitteln, intensive Düngung, die Erhöhung der Schlaggrößen, der Verlust von artenreichem Grünland und ein struktureller Wandel der Nutztierhaltung hin zu größeren Betrieben mit weniger Weidehaltung, der Verlust der Strukturvielfalt der Landschaft, aber auch der Verlust der Vernetzung von Schutzgebieten. Diese Ursachen sind im Wesentlichen bedingt durch die Intensivierung der Landnutzung und durch biologisch-technische Innovationen für die Erreichung von Produktionszielen. - Maßnahmen zum Schutz und zur Förderung der biologischen Vielfalt müssen die ökonomischen, politischen, rechtlichen und gesellschaftlichen Rahmenbedingungen in der Landwirtschaft be- rücksichtigen. Daher ist eine systemische Herangehensweise mit vielfältigen, parallelen Lösungsansätzen notwendig. Ansatzpunkte sind neben der Landwirtschaft die Agrarpolitik, die marktwirtschaftlichen Rahmenbedingungen, das Agrar- und Umweltrecht sowie die Zivilgesellschaft und die Wissenschaft.

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society. Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).