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Although anthropogenic stressors substantially impact insect biodiversity, few studies compare the drivers of trends among multiple taxa due to a lack of standardized time series data. This dissertation analyses 40 years of highly heterogeneous observation data from the central European region of Bavaria to determine occupancy changes of three insect taxa and evaluate potential drivers of trends. The effects of climate change, habitat preference, dependence on ants, and the EU Habitats Directive, among others, on butterfly, grasshopper, and dragonfly trends are discussed., Obwohl anthropogene Stressfaktoren Insekten erheblich beeinflussen, vergleichen nur wenige Studien die Ursachen für Trends verschiedener Taxa aufgrund eines Mangels an standardisierten Zeitreihendaten. Diese Dissertation analysiert 40 Jahre heterogener Beobachtungsdaten aus der zentraleuropäischen Region Bayern, um Veränderungen der Vorkommen dreier Insektentaxa festzustellen und potenzielle Ursachen für Trends zu bewerten. Unter anderem werden die Auswirkungen von Klimawandel, Ameisen-Abhängigkeit und der EU Flora-Fauna-Habitat Richtlinie diskutiert.

Evaluating the impact of future changes in land-use and climate on species communities, especially species richness, is one of the most important challenges of current research in ecology and conservation. The impact of environmental changes on species richness depends on its sensitivity (i.e., how strongly a given level of change influences the ecological community) and its exposure (i.e., the amount of change that occurs). To examine the sensitivity, exposure, and potential impact of future environmental conditions on bird communities, we compiled data on bird species richness for Pakistan—a neglected region in macro- or country-scale studies. Since bird species richness strongly varies across seasons due to the seasonal occurrence of migratory species in winter, we compared both wintering (migratory plus resident species) and breeding (resident species only) bird richness. We found breeding and wintering species richness to be sensitive to temperature, precipitation and rainfed cropland by being positively related to these factors. Exposure varied regionally, with projected temperature changes being most profound in northern regions while the strongest projected precipitation changes occurred in central and southern regions. The projected impact of future environmental change were highly heterogeneous across the country and differed between the wintering and breeding communities. Overall, the most negatively impacted region was projected to be the Khyber Pakhtunkha province in the North of Pakistan, due to reductions in precipitation and rainfed cropland, resulting in a projected negative impact, especially on wintering species richness. By highlighting the regional and seasonal bird communities most at risk, our findings provide useful information for policy makers to help devise new policies for mitigating negative impacts of future environmental changes on birds within Pakistan.

Strong biodiversity declines have been reported across the European Union, especially in insects, despite conservation policy such as the Habitats Directive that aims to halt biodiversity loss. Using 50 years of observational data, we examined indicators for the goals of the Directive in terms of improving monitoring efforts and occupancy trends of butterfly and dragonfly annex species in a central European region. We quantified annual monitoring effort and used occupancy-detection models to compare species trends for 18 years before and after legal implementation of the Directive. Monitoring efforts increased after implementation, while occupancy trends both improved and deteriorated. Contrary to its main goal, the European Habitats Directive did not prevent a worsening of all annex species’ occupancy trends in the studied region. While the increased monitoring efforts aid biodiversity assessments, more serious broad-scale conservation measures are needed to halt biodiversity loss across Europe.

Climate warming is considered to be among the most serious of anthropogenicstresses to the environment, because it not only has direct effects on biodiver-sity, but it also exacerbates the harmful effects of other human-mediated threats. The associated consequences are potentially severe, particularly interms of threats to species preservation, as well as in the preservation of anarray of ecosystem services provided by biodiversity. Among the most affectedgroups of animals are insects—central components of many ecosystems—forwhich climate change has pervasive effects from individuals to communities.In this contribution to the scientists’warning series, we summarize the effectof the gradual global surface temperature increase on insects, in terms ofphysiology, behavior, phenology, distribution, and species interactions, as wellas the effect of increased frequency and duration of extreme events such as hotand cold spells, fires, droughts, and floods on these parameters. We warn that,if no action is taken to better understand and reduce the action of climatechange on insects, we will drastically reduce our ability to build a sustainablefuture based on healthy, functional ecosystems. We discuss perspectives onrelevant ways to conserve insects in the face of climate change, and we offerseveral key recommendations on management approaches that can beadopted, on policies that should be pursued, and on the involvement of thegeneral public in the protection effort.

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The establishment and maintenance of protected areas(PAs) is viewed as a key action in delivering post-2020 biodiversity targets. PAs often need to meet a multitude of objectives, ranging from biodiversity protection to ecosystem service provision and climate change mitigation. As available land and conservation funding are limited, optimizing resources by selecting the most beneficial PAs is vital. Here we present a decision support tool that enables a flexible approach to PA selection on a global scale, allowing different conservation objectives to be weighted and prioritized according to user-specified preferences. We apply the tool across 1347 terrestrial PAs and highlight frequent trade-offs among different objectives, e.g., between biodiversity protection and ecosystem integrity. These results indicate that decision makers must usually decide among conflicting objectives. To assist this our decision support tool provides an explicitly value-based approach that can help resolve such conflicts by considering divergent societal and political demands and values.