Das Projekt "The importance of local habitat fragmentation versus landscape composition for biodiversity conservation and ecosystem services in agricultural landscapes - FRAGMENT" wird vom Umweltbundesamt gefördert und von Forschungsanstalt Agroscope Reckenholz-Tänikon ART durchgeführt. The loss and fragmentation of semi-natural habitats are a major threat to biodiversity in agricultural landscapes, with potential negative consequences for the biological control of pest insects and pollination of crop plants. As habitat loss and fragmentation usually occur together, most existing studies have examined only their combined effect. While habitat loss usually has large, consistently negative effects on biodiversity, the effect of fragmentation per se is little known. Habitat isolation, expressed as the distance to neighbouring habitat patches, is one aspect of habitat fragmentation that is expected to reduce biodiversity. Habitat loss can be expressed as the change of landscape composition, i.e. the reduction of the share of a landscape covered by suitable habitat. The proposed study differentiates between the effect of habitat isolation and landscape composition on biodiversity, pollination and pest control. To this end we planted groups of young cherry trees as standardised habitat patches in 2008, which will be the study sites for 2010 - 2012.Thirty groups of seven trees were established along a gradient of landscape composition. The percentage of woody habitats ranges from 3.6 to 74.2Prozent within 500 m radius around the sites. Independent of this gradient in landscape composition, the study sites have three levels of habitat isolation: Ten of the sites are located at the edge of dense and tall-growing forest to represent no isolation from native habitat. Another 10 sites are connected to small-sized woody habitats such as hedgerows or single trees. The remaining 10 sites are isolated from any woody habitat by at least 100 m distance. Diversity, density and parasitism of arthropods are recorded and analysed with respect to habitat isolation and landscape composition. In addition, experiments are conducted in the field to quantify the influence of predators and parasitoids on black cherry aphids. Further, we study flower visitation and pollination success of the cherry trees. The two ecosystem services aphid control and pollination are analysed with respect to habitat isolation and landscape composition. As the planted cherry trees will be followed over five years, we will be able to test the influence of habitat age on effects of habitat isolation and landscape composition.
Das Projekt "Evolutionary ecology of floral signals and pollinator specificity in plants" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Agrarwissenschaften, Departement Biologie durchgeführt. Plants grow in complex ecological networks, and show finely tuned adaptations to attact mutualists such as pollinators, and deter enemies such as herbivores. To do so, plants use volatile signals (BVOCs biogenic volatile organic compounds) that are emitted from vegetative (e.g. leaves) or flowers. Leaf volatiles are often thought to be involved in defense, whereas floral volatiles are traditionally interpreted as attractants for pollinators. However, recent studies have shown that floral scent may as well be involved in defending reproductive structures against antagonists. This can be achieved by emitting repellent compounds from flowers. The obvious need of plants to attract pollinators to flowers on the one hand, and to defend flowers on the other hand, puts them into a dilemma. Such signaling dilemma or trade-offs suggest optimal fitness outcomes may be a compromise between attraction (pollinators, parasitoids) and deterrence (herbivores); a key factor selecting for differential signaling may thus be the abundance and species identity of these interacting organisms in a given habitat. Signaling conflicts may also differ among pollination systems, e.g. when pollinators are also herbivores (moth pollination), attracting an herbivore is unavoidable for pollination. Under strong herbivore attack, however, plants may even switch pollination system by changing BVOC signaling to escape the herbivore pressure. This particular project will focus on ecological and evolutionary aspects of flower signaling to pollinators and the impact of novel herbivores on this mutualism. Up till now, we know surprisingly little about how herbivore induced changes in floral volatiles (HICFV) and the resulting change in flower attractiveness to pollinators. This IP will investigate HICFV after attack of established and novel herbivores (both on shoots and roots) and its molecular basis and variability. Lastly, natural selection on HICFV will be studied in populations with and without invasive herbivores, to asses their impact on the evolution of this key plant signaling trait and model future evolutionary change.
Das Projekt "Evaluating current European agri-environment schemes to quantify and improve nature conservation efforts in agricultural landscapes (EASY)" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. Research question: Agri-environment schemes play an increasingly important role in European CAP (Common Agricultural Policy) to support biodiversity and environment in agricultural landscapes. They have been implemented since 1992 and now cost a yearly 1.7 billion Euro. Still, there is no conclusive evidence that these schemes actually do contribute to the conservation of particularly biodiversity. The primary objective of this project is to evaluate the (cost-) effectiveness of European agri-environment schemes in protecting biodiversity and to determine the primary processes that determine their effectiveness. This project furthermore aims to determine how CAP may be introduced in candidate EU-members without unacceptable loss of biodiversity. It will provide simple guidelines how researchers, governmental authorities may efficiently evaluate agri-environmental measures. Aim: Agri-environment schemes have been used to protect biodiversity and environment in agricultural areas since 1992. Their effectiveness has never been reliably evaluated. This project aims to evaluate the (cost-)effectiveness of agri-environment schemes with respect to biodiversity conservation in five European countries. It will determine the proper scales that have to be addressed for conservation efforts for a range of species groups. It will determine the most important environmental factors that influence the effectiveness of the schemes. Based on this, recommendations will be made how the effectiveness of schemes may be improved and simple guidelines will be produced how ecological effects of agri-environment schemes can be evaluated efficiently by governmental authorities or other institutions. The ecological effects of the introduction of CAP in a candidate EU-member will be investigated to reduce negative side effects of anticipated land-use changes Scientific methods: We will examine the effectiveness of agri-environment schemes by surveying pairs of fields: a field with an agri-environment scheme and a nearby field that is conventionally managed. In five countries, in each country in three areas, and in each area on seven pairs of fields the species richness of birds, plants and three insect groups (pollinators, herbivores, predators) will be determined. Effects of schemes on pollination efficiency and pest control will be examined using indicator communities. Correlative studies will examine the effects of landscape structure, land-use intensity and species pool on the effectiveness of agri-environmental measures. The spatial scale that is relevant to nature conservation efforts will be investigated via the spatial distribution of species groups. The results will be used to formulate recommendations how to improve the effectiveness of agri-environment schemes and to construct a set of simple guidelines how schemes can be evaluated efficiently yet reliably.
Das Projekt "Populationsdynamik von Epiphyten" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Botanik durchgeführt. Epiphyten, Pflanzen die auf Bäumen wachsen ohne an diesen zu parasitieren und ohne Wurzelkontakt zum Boden, sind typische Elemente tropischer Regenwälder und tragen wesentlich zu deren Diversität bei. Da sie, wenn sie zu Boden fallen, kaum überleben, hängt ihr Lebenszyklus stark von dem der sie tragenden Bäume und Äste ab. Zudem stellt ihr Lebensraum, die Kronenregion des Waldes, ein heterogenes und strukturiertes Habitat dar, mit starken Unterschieden in Mikroklima, Substrat auf den Ästen und deren Stabilität, was zu einer deutlichen Zonierung in der Verteilung der Epiphyten führt. Im Laufe ihres Lebenszyklus müssen Pflanzen bestäubt werden, Samen produzieren und diese müssen auf geeigneten Ästen landen und keimen. Wachstums- und Überlebensraten bestimmen die Wahrscheinlichkeit mit der die Pflanze später selbst Blüten produzieren wird. Alle diese Faktoren sind von Art zu Art unterschieden, können aber auch von der Position einer Pflanze innerhalb des Baumes abhängen. Letztendlich bestimmen Überleben, Wachstum, Vermehrung und Samenverbreitung selbst die Verteilung der Pflanzen innerhalb des Baumes. Das beantragte Projekt soll den Zusammenhang zwischen der Verteilung der Pflanzen in den Kronen und den Lebenszyklen einiger Orchideen und Bromelien in einem humiden Bergwald in Mexiko untersuchen. Populationsgenetische Analysen sollen feststellen, wieweit die räumlichen Verteilung der Individuen, die teils sehr heterogen ist, mit deren genetischer Distanz zusammenhängt. Die untersuchten Zusammenhänge werden in Populationsmodelle integriert, die zu einem besseren Verständnis der Populationsdynamik von Epiphyten und letztendlich der Struktur und Dynamik im Kronenraum beitragen sollen. Dies ist auch von Bedeutung, wenn die Aussichten einzelner Arten in vom Menschen veränderten Lebensräumen abgeschätzt werden sollen.