Wolfgang Weisser

Technische Universität München | TUM · School of Life Sciences Weihenstephan

Biodiversity underlies many of the ecosystem services demanded by humans. For cities, the design of 'green infra-structures' or 'nature-based solutions' has been proposed to maintain the provisioning of these services and the preservation of biodiversity. It is unclear, however, how such green infrastructure can be implemented, given existing plann...

In the past two decades, a large number of studies have investigated the relationship between biodiversity and ecosystem functioning, most of which focussed on a limited set of ecosystem variables. The Jena Experiment was set up in 2002 to investigate the effects of plant diversity on element cycling and trophic interactions, using a multi-discipli...

Biodiversity ensures ecosystem functioning and provisioning of ecosystem services, but it remains unclear how biodiversity-ecosystem multifunctionality relationships depend on the identity and number of functions considered. Here, we demonstrate that ecosystem multifunctionality, based on 82 indicator variables of ecosystem functions in a grassland...

Background Plants grow in multi-species communities rather than monocultures. Yet most studies on the emission of volatile organic compounds (VOCs) from plants in response to insect herbivore feeding focus on one plant species. Whether the presence and identity of neighboring plants or plant community attributes, such as plant species richness and...

The ontogenetic niche concept predicts that resource use depends on an organism’s developmental stage. This concept has been investigated primarily in animals that show differing resource use strategies as juveniles and as adults, such as amphibians. We studied resource use and performance in the grasshopper Chorthippus parallelus (Orthoptera, Acri...

Understanding the variation in community composition and species abundances (i.e., β‐diversity) is at the heart of community ecology. A common approach to examine β‐diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance. We p...

Deadwood is an important component of the global carbon cycle, and its decomposition releases carbon dioxide (CO2) and methane (CH4) into the atmosphere. However, the main drivers of these greenhouse gas emissions from deadwood are not well understood. We investigated drivers that govern the CO2 and CH4 emission rates of 793 deadwood specimens from...

Positive effects of plant species richness on community biomass in biodiversity experiments are often stronger than those from observational field studies. This may be because experiments are initiated with randomly assembled species compositions whereas field communities have experienced filtering. We compared aboveground biomass production of ran...

Temporal trends in insect numbers vary across studies and habitats, but drivers are poorly understood. Suitable long-term data are scant and biased, and interpretations of trends remain controversial. By contrast, there is substantial quantitative evidence for drivers of spatial variation. From observational and experimental studies, we have gained...

Key message TLS scans of three surveys before, during and after gypsy moth gradation, allowed high-resolution tracking of defoliation and subsequent inter-annual growth losses on an individual tree level. Abstract Foliation strongly determines all tree growth processes but can be reduced by various stress factors. Insect defoliation starts at vari...

Forestry in Europe changed the tree species composition and reduced dead-wood amount and heterogeneity, and therefore negatively affected saproxylic diversity. Efficient conservation requires knowledge about the importance of the relevant diversity drivers across taxa. We examined the relative importance of space vs. host for saproxylic diversity a...

1. Bat populations are in steep decline and presently, 16% of all species are classified as 'threatened'. One main driver identified for this decline is the loss of natural roosting opportunities, caused by the removal of natural habitats. Installation of bat boxes is one solution to compensate for the lack of natural roosting opportunities. Curren...

Context Current diversity and species composition of ecological communities can often not exclusively be explained by present land use and landscape structure. Historical land use may have considerably influenced ecosystems and their properties for decades and centuries. Objectives We analysed the effects of present and historical landscape struct...

Biodiverse communities have been shown to sustain high levels of multifunctionality and thus a loss of species likely negatively impacts ecosystem functions. For most taxa, however, roles of individual species are poorly known. Rare species, often most likely to go extinct, may have unique traits and functional roles. Alternatively, rare species ma...

Current modelling approaches to predict spatially explicit biodiversity responses to climate change mainly focus on the direct effects of climate on species. Integration of spatiotemporal land-cover scenarios is still limited. Current approaches either regard land cover as constant boundary conditions, or rely on general, typically globally defined...

1.The patterns of successional change of decomposer communities is unique in that resource availability predictably decreases as decomposition proceeds. Saproxylic (i.e., deadwood-dependent) beetles are a highly diverse and functionally important decomposer group, and their community composition is affected by both deadwood characteristics and othe...

1. Insecticides used to combat outbreaks of forest defoliators can adversely affect non-target arthropods. Forestry insecticides typically suppress Lepidoptera larvae which are the cornerstone of the canopy community of deciduous oak forests. The abrupt removal of this dominant component of the food web could have far-reaching implications for fore...

Cities have been shown to be biodiverse, but it is unclear what fraction of a regional species pool can live within city borders and how this differs between taxa. Among animals, most research has focused on a few well-studied taxa, such as birds or butterflies. For other species, progress is limited by the paucity of data. We used species occurren...

Agricultural diversification of intensified farming systems is being proposed as a solution for achieving both food security and agricultural sustainability, but so far there has been little implementation of such policy at a larger scale. In China, major policies promote the “High-standard farmland consolidation” (HSFC) strategy to improve product...

Floral plantings are often used in agriculture to attract pollinator communities, but they also play an important role in recruiting and establishing natural communities for natural pest control. Inconsistent effects of floral plantings for pest control may be a result of an absence of mechanistic insights and a reliance on the idea that simply inc...

Background How land use shapes biodiversity and functional trait composition of animal communities is an important question and frequently addressed. Land-use intensification is associated with changes in abiotic and biotic conditions including environmental homogenization and may act as an environmental filter to shape the composition of species c...

Understanding how land use and management practices affect biodiversity is essential for developing effective restoration and conservation strategies. Here, we used ant communities to evaluate the effects of historical land uses (former agriculture or tree plantation) and current management (grazing, burning, mowing, and fertilizing) in subtropical...

Urban areas are facing significant challenges regarding degradation of environments and ecosystems, species loss, and increased vulnerability to climate hazards, all of which impact negatively upon human health and well-being.Focusing on building envelopes can offer an effective approach to the regeneration of urban ecosystems, by providing new spa...

• Among the many concerns for biodiversity in the Anthropocene, recent reports of flying insect loss are particularly alarming, given their importance as pollinators, pest control agents, and as a food source. Few insect monitoring programmes cover the large spatial scales required to provide more generalizable estimates of insect responses to glob...

Abstract Aim: The aim of this study was to investigate the role of traits in beetle community assembly and test for consistency in these effects among several bioclimatic regions. We asked (1) whether traits predicted species’ responses to environmental gradients (i.e. their niches), (2) whether these same traits could predict co- occurrence patt...

Central Europe's temperate forests are heavily shaped by centuries of human activity. Their natural vegetation, mainly consisting of beech-dominated (Fagus sylvatica) deciduous forests, has been widely replaced by more profitable species grown outside of their natural ranges. This has strongly influenced forest-dwelling communities. Necessary adapt...

Outbreaks of folivorous insects are a major problem in managed forests causing significant economic losses each year in temperate regions. To limit these losses, insecticides can be applied by aircraft when granted approval. The decision-makers have to weigh up between protecting the forest from defoliation and protecting non-target species from th...

1. Schall et al. (2020) assessed how a combination of different forest management systems in managed forest landscapes dominated by European beech may affect the biodiversity (alpha, beta and gamma) of 14 taxonomic groups. Current forest policy and nature conservation often demand for combining uneven-aged managed and unmanaged, set-aside for natur...

The amount of carbon stored in deadwood is equivalent to about 8 per cent of the global forest carbon stocks1. The decomposition of deadwood is largely governed by climate2–5 with decomposer groups—such as microorganisms and insects—contributing to variations in the decomposition rates2,6,7. At the global scale, the contribution of insects to the d...

The ability of insects to persist in urban greenspace depends on their ability to usefully interact with available plant resources. Greenspace design influences plant–insect interactions by: (1) limiting the plant-species pool available for interaction through plant choice, (2) limiting the insects that are available for interaction through site-oc...

Quantifying tree defoliation by insects over large areas is a major challenge in forest management, but it is essential in ecosystem assessments of disturbance and resistance against herbivory. However, the trajectory from leaf‐flush to insect defoliation to refoliation in broadleaf trees is highly variable. Its tracking requires high temporal‐ and...

Reversing the decline of biodiver-sity in European agricultural land-scapes is urgent. We suggest eightmeasures addressing politics, eco-nomics, and civil society to instigatetransformative changes in agricul-tural landscapes. We emphasizethe need for a well-informed societyand political measures promotingsustainable farming by combiningfood produc...

Land-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local-and l...

Land-use intensification poses major threats to biodiversity, such as to insect herbivore communities. The stability of these communities depends on interactions linking herbivores and host plants. How interaction network structure begets robustness, and thus stability, in different ecosystems and how network structure and robustness are altered al...

Cities are designed for humans but are also highly dynamic ecosystems that provide habitats for wild animals. These habitats depend on a city's green infrastructure which is increasingly threatened by urban densification. A commonly studied model taxon for wild animals in cities are birds, and the importance of large green spaces for the diversity...

Internal feeding is considered to shield sessile herbivore insects from exposure to non‐systemic insecticides aerially sprayed against forest defoliators, though this has not been tested. It is, however, established that leaf damage caused by defoliators affect the survivorship and oviposition behavior of sessile herbivores. Feeding ecology and com...

Understanding the variation in community composition and species abundances, i.e., β-diversity, is at the heart of community ecology. A common approach to examine β-diversity is to evaluate directional turnover in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distances. We p...

Conservation biology is designed to identify pressing environmental problems and to solve them. This review evaluates the relative effort of conservation biology in problem-based and solution-based research, and tests whether or not this has changed in the past decades for five major drivers of biodiversity loss, i.e. habitat loss and fragmentation...

Pearl bodies are produced by some plant species as food reward for ants and in exchange, ants defend these plants against insect pests. Sap-sucking pests such as aphids also excrete honeydew as food reward for ants, leading to potential conflict where ants could preferentially defend either the plant or the aphid. How pest insects might influence p...

Intraguild predation is the killing and consuming of a heterospecific competitor that uses similar resources as the prey, and also benefit from preying on each other. We investigated the foraging behaviour of the gallmidge, Aphidoletes aphidimyza , a predator of aphids used for biological control that is also the intraguild prey for most other aphi...

Decomposition, vegetation regeneration, and biological control are essential ecosystem functions, and animals are involved in the underlying processes, such as dung removal, seed removal, herbivory, and predation. Despite evidence for declines of animal diversity and abundance due to climate change and land-use intensification, we poorly understand...

Aim Despite increasing interest in β-diversity, i.e. the spatial and temporal turnover of species, the mechanisms underlying species turnover at different spatial scales are not fully understood, although they likely differ among different functional groups. We investigated the relative importance of dispersal limitations and the environmental filt...

1. Gypsy moth outbreaks cause severe defoliation in Holarctic forests, both in North America where it is invasive, and in its native range in Eurasia. Defoliation can hamper timber production and impact ecological communities and processes. Aerial insecticide applications are regularly performed in outbreak areas to mitigate economic losses. These...

Among the many concerns for biodiversity in the Anthropocene, recent reports of flying insect loss are particularly alarming, given their importance as pollinators and as a food source for many predators. Few insect monitoring programs cover large spatial scales required to provide more generalizable estimates of insect responses to global change d...

Background Forests perform various important ecosystem functions that contribute to ecosystem services. In many parts of the world, forest management has shifted from a focus on timber production to multi-purpose forestry, combining timber production with the supply of other forest ecosystem services. However, it is unclear which forest types provi...

• Reports of major losses in insect biodiversity have stimulated an increasing interest in temporal population changes. Existing datasets are often limited to a small number of study sites, few points in time, a narrow range of land‐use intensities and only some taxonomic groups, or they lack standardised sampling. While new monitoring programs hav...

Gebäude gelten derzeit als umweltfreundlich, wenn sie der Natur möglichst wenig Schaden zufügen und einen möglichst kleinen ökologischen Fußabdruck hinterlassen. Gemessen wird dies meist an ihrem Energieverbrauch. Aus diesem Grunde wird die Interaktion des Gebäudes mit der Umwelt durch eine Maximierung der Dämmung und eine Minimierung der Außenfläc...

Background Tansy plants (Tanacetum vulgare L.) are known for their high intraspecific chemical variation, especially of volatile organic compounds (VOC) from the terpenoid compound group. These VOCs are closely involved in plant-insect interactions and, when profiled, can be used to classify plants into groups known as chemotypes. Tansy chemotypes...

Ecosystems integrity and services are threatened by anthropogenic global changes. Mitigating and adapting to these changes requires knowledge of ecosystem functioning in the expected novel environments, informed in large part through experimentation and modelling. This paper describes 13 advanced controlled environment facilities for experimental e...

Earth is home to over 350,000 vascular plant species that differ in their traits in innumerable ways. A key challenge is to pre- dict how natural or anthropogenically driven changes in the identity, abundance and diversity of co-occurring plant species drive important ecosystem-level properties such as biomass production or carbon storage. Here, we...

While there is growing consensus that nature should be promoted in cities, it is less clear what kind of nature this should be. One hypothesis is that humans like those parts of nature morethat they know better. Using questionnaires, we studied the familiarity of 475 students with 91 urban animal species and the relationship between familiarity and...

Land-use intensification can increase provisioning ecosystem services, such as food and timber production, but it also drives changes in ecosystem functioning and biodiversity loss, which may ultimately compromise human wellbeing. To understand how changes in land-use intensity affect the relationships between biodiversity, ecosystem functions, and...

Arthropod herbivores cause substantial economic costs that drive an increasing need to develop environmentally sustainable approaches to herbivore control. Increasing plant diversity is expected to limit herbivory by altering plant-herbivore and predator-herbivore interactions, but the simultaneous influence of these interactions on herbivore impac...

A large body of research shows that biodiversity loss can reduce ecosystem functioning. However, much of the evidence for this relationship is drawn from biodiversity–ecosystem functioning experiments in which biodiversity loss is simulated by randomly assembling communities of varying species diversity, and ecosystem functions are measured. This r...

Reports of major losses in biodiversity have stimulated an increasing interest in temporal population changes, particularly in insects, which had received little attention in the past. Existing long-term datasets are often limited to a small number of study sites, few points in time, a narrow range of land-use intensities and only some taxonomic gr...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

• The enemy release hypothesis (ERH) attributes the success of some exotic plant species to reduced top‐down effects of natural enemies in the non‐native range relative to the native range. Many studies have tested this idea, but very few have considered the simultaneous effects of multiple kinds of enemies on more than one invasive species in both...

The habitat heterogeneity hypothesis predicts that biodiversity increases with increasing habitat heterogeneity due to greater niche dimensionality. However, recent studies have reported that richness can decrease with high heterogeneity due to stochastic extinctions, creating trade-offs between area and heterogeneity. This suggests that greater co...

Climate change is altering the dynamics of crop pests and diseases resulting in reduced crop yields. Using beneficial soil bacterial to increase crop health is a quickly developing area in sustainable agriculture, but it is unknown if climate change or interactions with other species could alter their effect. The plant growth-promoting rhizobacteri...

Table of contents S1: Relation of seed removal rate with short-term precipitation S2: Details of herbivory measurements S3: Details of processing explanatory data S4: GLMM results in detail S5: Comparison of the mean effect sizes of short-term vs. medium-term land-use variables in grasslands S6: Process rates in detail S7: Effects of the vegetation...

1. Land‐use intensification leads to loss and degradation of habitats and is thus a major driver of biodiversity loss. Restoration strategies typically focus on promoting biodiversity but often neglect that land‐use intensification could have changed the underlying mechanisms of community assembly. Since assembly mechanisms determine the diversity...