Roel van Klink

German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig | iDiv · Biodiversity Synthesis

Insects are the most diverse group of animals on Earth, yet our knowledge of their diversity, ecology and population trends remains abysmally poor. Four major technological approaches are coming to fruition for use in insect monitoring and ecological research—molecular methods, computer vision, autonomous acoustic monitoring and radar-based remote...

Due to rapid technological innovations, the automated monitoring of insect assemblages comes within reach. However, this continuous innovation endangers the methodological continuity needed for calculating reliable biodiversity trends in the future. Maintaining methodological continuity over prolonged periods of time is not trivial, since technolog...

It is commonly thought that the biodiversity crisis includes widespread declines in the spatial variation of species composition, called biotic homogenization. Using a typology relating homogenization and differentiation to local and regional diversity changes, we synthesize patterns across 461 metacommunities surveyed for 10 to 91 years, and 64 sp...

Studies have reported widespread declines in terrestrial insect abundances in recent years1–4, but trends in other biodiversity metrics are less clear-cut5–7. Here we examined long-term trends in 923 terrestrial insect assemblages monitored in 106 studies, and found concomitant declines in abundance and species richness. For studies that were resol...

Due to rapid technological innovations, the automated monitoring of insect assemblages comes within reach. However, this continuous innovation endangers the methodological continuity needed for calculating reliable biodiversity trends in the future.Maintaining methodological continuity over prolonged periods of time is not trivial, since technology...

Rösch, V., Biedermann, R., Entling, M.H., Gjonov, I., Helbing, F., Jakovljević, M., van Klink, R., Marinković, S., Sára, A., Sára, H., Schuch, S., & Achtziger, R. (2023): Leafhopper diversity in home gardens – results of a survey in four countries across Europe (Hemiptera, Auchenorrhyncha). Cicadina 22: 39-57. // Despite urbanisation being one of t...

Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is thought to be shrinking in the Anthropocene. Here, we assessed the prevalence of body size change in six taxon groups across 5025 assemblage time series spanning 1960 to 202...

Whether most species are rare or have some intermediate abundance is a long-standing question in ecology. Here, we use more than one billion observations from the Global Biodiversity Information Facility to assess global species abundance distributions (gSADs) of 39 taxonomic classes of eukaryotic organisms from 1900 to 2019. We show that, as sampl...

Global change alters the stability of biological communities by affecting species richness and how species covary through time (i.e., synchrony). There are few large-scale empirical tests of stability-diversity-synchrony relationships and those mostly focus on the terrestrial realm. Moreover, the effect of synchrony is largely unknown when species...

Rösch, V., Achtziger, R., Adam, P., Andreä, J., Attinger, A., Edo, M., Frenzel, M., Kramer, D., Malenovský, I., Mollmann, C., Mühlethaler, R., Nickel, H., Niedringhaus, R., van Klink, R., Walter, S., Witsack, W. & Zeman, Š. (2023): Zur Fauna der Zikaden, Wanzen und Blattflöhe der Pfalz, Deutschland (Hemiptera: Auchenorrhyncha, Heteroptera und Psyll...

Over the past decades, studies have observed strong declines in biomass and the abundance of flying insects. However, there are many locations where no surveys of insect biomass or abundance are available. Weather radars are known to provide quantitative estimates of flying insect biomass and abundance, and can therefore be used to fill knowledge g...

Ground beetles (Coleoptera: Carabidae) have been used as an indicator group for all sorts of ecological and conservation related questions for many decades. The book ‘Ecology And Conservation Of The Dutch Ground Beetle Fauna – Lessons From 66 Years Of Pitfall Trapping’ by Hans Turin and colleagues reanalyses research on Dutch ground beetle done ove...

While human activities are known to elicit rapid turnover in species composition through time, the properties of the species that increase or decrease their spatial occupancy underlying this turnover are less clear. Here, we used an extensive dataset of 238 metacommunity time series of multiple taxa spread across the globe to evaluate whether speci...

Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is often thought to be shrinking in the Anthropocene. Here, we assess the prevalence of body size change in six taxon groups across 5,032 assemblage time-series spanning 1960-2...

Declines in insect biomass and individual numbers have been demonstrated in many parts of the world, including central European dry grasslands. It is, howver, unclear if biomass data or individual numbers are superior as measures of change in species composition, and in trait composition of insect communities. We revisited a former study of ours de...

Fragmentation of habitat, for example by intensive agricultural practices, can be detrimental to local biodiversity. However, it often remains unclear whether such biodiversity declines are caused by loss of habitat area or increased fragmentation, and how habitat quality factors into it. In our study system, vegetated vineyards are typically small...

Ecological thresholds comprise relatively fast changes in ecological conditions, with respect to time or external drivers, and are an attractive concept in both scientific and policy arenas. However, there is considerable debate concerning the existence, underlying mechanisms, and generalizability of ecological thresholds across a range of ecologic...

It is commonly thought that the biodiversity crisis includes widespread decreases in the uniqueness of different sites in a landscape (biotic homogenization). Using a typology relating homogenization and differentiation to local and regional diversity changes, we synthesize patterns across 283 metacommunities surveyed for 10-91 years, and 54 specie...

Insects are the most diverse group of animals on Earth, but their small size and high diversity have always made them challenging to study. Recent technological advances have the potential to revolutionise insect ecology and monitoring. We describe the state of the art of four technologies (computer vision, acoustic monitoring, radar, and molecular...

Climate change and land-use intensification pose increasing threats to biodiversity, with climate change expected to eventually surpass other global environmental change drivers and become the greatest threat to biodiversity in the future. Understanding the combined ecological impacts of multiple global change drivers is crucial to predict future s...

Changes in the abundances of animals, such as with the ongoing concern about insect declines, are often assumed to be general across taxa. However, this assumption is largely untested. Here, we used a database of assemblage-wide long-term insect and arachnid monitoring to compare abundance trends among co-occurring pairs of taxa. We show that 60% o...

Dit rapport geeft een overzicht van de resultaten van onderzoek naar loopkevers in een klein bosgebied in de provincie Drenthe, het Mantingerbos. Het onderzoek werd in 1959 gestart door Piet den Boer, herhaald in de zeventiger en tachtiger jaren van de vorige eeuw en opnieuw herhaald gedurende 2019-2021. Geconcludeerd wordt dat de soortenrijkdom ge...

Trivellone, V., Achtziger, R., Fründ, E., Funke, L., Hollier, J., Holzinger, W.E., Huber, E., Kunz, G., Mühlethaler, R., Nickel, H., Niedringhaus, R., Panassiti, B., Ramsay, A., Rösch, V., Seljak, G., van Klink, R. & Pollini Paltrinieri, L. (2021): Auchenorrinchi ed eterotteri (Hemiptera) di ecosistemi naturali di rilevante valore in Cantone Ticino...

National and local governments need to step up efforts to effectively implement the post‐2020 global biodiversity framework of the Convention on Biological Diversity to halt and reverse worsening biodiversity trends. Drawing on recent advances in interdisciplinary biodiversity science, we propose a framework for improved implementation by national...

Achtziger, R., Chen, P-P., Funke, L., Hartung, V., van Klink, R., Malenovský, I., Nickel, H., Nieser, N., Rösch, V., Walter, S., Zeman, Š. & Jessat, M. (2020): Zur Zikaden- und Wanzenfauna von Wasserbüffelweiden und angrenzenden Standorten im Altenburger Land – Ergebnisse der Sammelexkursionen zur 26. Jahrestagung des Arbeitskreises Mitteleuropäisc...

Reassembling ecological communities and rebuilding habitats through active restoration treatments require curating the selection of plant species to use in seeding and planting mixes. Ideally, these mixes should be assembled based on attributes that support ecosystem function and services, promote plant and animal species interactions and ecologica...

Insects are the most ubiquitous and diverse group of eukaryotic organisms on Earth, forming a crucial link in terrestrial and freshwater food webs. They have recently become the subject of headlines because of observations of dramatic declines in some places. Although there are hundreds of long‐term insect monitoring programs, a global database for...

Reassembling ecological communities and rebuilding habitats through active restoration treatments requires curating the selection of plant species to use in seeding and planting mixes. Ideally, these mixes should be assembled based on attributes that support ecosystem function and services, promote plant and animal species interactions and ecologic...

Jähnig et al. make some useful points regarding the conclusions that can be drawn from our meta‐analysis; however, some issues require clarification. First, we never suggested that there was a globally increasing trend of freshwater insect abundances, but only spoke of an average increasing trend in the available data. We also did not suggest that...

Desquilbet al. take issue with our data inclusion criteria and make several other dubious claims regarding data processing, analysis, and interpretation. Most of their concerns stem from disagreement on data inclusion criteria and analysis, misunderstanding of our goals, and unrealistic expectations. We maintain that our synthesis provides a state-...

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved....

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved....

The effect of rotation grazing on the biodiversity of salt marshes. In order to halt succession and to control the dominance of sea couch grass on salt marshes along the Wadden Sea coast, livestock grazing is often used for conservation management. Grazing is generally applied seasonally at constant stocking densities. Rotation grazing, where grazi...

Local drivers of decline matter Recent studies have reported alarming declines in insect populations, but questions persist about the breadth and pattern of such declines. van Klink et al. compiled data from 166 long-term surveys across 1676 globally distributed sites and confirmed declines in terrestrial insects, albeit at lower rates than some ot...

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

Carrion of large animals is an extremely nutrient rich, ephemeral resource that is essential for many species, but is scarce in the anthropogenic Western-European landscape due to legislative restrictions. Rewilding, a novel conservation strategy that aims at restoring natural processes with minimal human intervention, is increasing in popularity a...

The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear...

The 25th Central European Auchenorrhyncha meeting took place in Arnhem, The Netherlands on 14−17 September 2018. It was the first time the meeting was held in The Netherlands, and for this reason, excursions were undertaken to five typical Dutch landscapes. Three of the excursions involved newly created nature reserves, located on former agricultur...

Recently, reports of insect declines prompted concerns with respect to the state of insects at a global level. Here, we present the results of longer‐term insect monitoring from two locations in the Netherlands: nature development area De Kaaistoep and nature reserves near Wijster. Based on data from insects attracted to light in De Kaaistoep, macr...

Facilitating “wildness” Humans have encroached upon a majority of Earth's lands. The current extinction crisis is a testament to human impacts on wilderness. If there is any hope of retaining a biodiverse planetary system, we must begin to learn how to coexist with, and leave space for, other species. The practice of “rewilding” has emerged as a me...

The temporal stability of communities is essential for the maintenance of ecosystem functioning across trophic levels. The stabilizing effect of biodiversity is, among other factors, modulated by the level of synchrony in population fluctuations among the species in the community. What drives community synchrony, however, remains largely unclear. C...

The current debate on the general decline of insects throughout Germany lacks well-documented long-term studies. This is due to the immense diversity of insects, the associated effort for identification, and finally the lack of standardised collection procedures. We revisited own studies on the abundances of leafhoppers and planthoppers from the ye...

For the restoration of biodiversity in agricultural grasslands, it is essential to understand how management acts as an ecological filter on the resident species. Mowing constitutes such a filter: only species that possess functional traits enabling them to withstand its consequences can persist in the community. We investigated how the timing of m...

Trophic rewilding is a restoration strategy focusing on the restoration of trophic interactions to promote self-regulating, biodiverse ecosystems. It has been proposed as an alternative to traditional conservation management in abandoned or defaunated areas. Arthropods constitute the most species-rich group of eukaryotic organisms, but are rarely c...

Recently, reports of insect declines prompted concerns with respect to the state of insects at a global level. Here we present the results of long-term insect monitoring from two locations, De Kaaistoep, and nature reserves in Drenthe, both in the Netherlands. We report the trends in beetles (Coleoptera), macro-moths (macro-Lepidoptera), caddis ies...

The faunistics of Prokelisia marginata in The Netherlands and Northern Germany

Effects of livestock grazing of coastal salt marshes on spiders and insects We performed two experiments to assess how livestock grazing affects spiders and insects on two coastal salt marshes at the Wadden sea coast, the Netherlands: the mainland marsh Noord-Friesland Buitendijks (NFB) and the island marsh of Schiermonnikoog. We trapped epigeic fa...

Host-plant associations of the Auchenorrhyncha and Psylloid fauna of the Noardlike Fryske Wâlden (Hemiptera) Host plant associations and diet breadth are important traits of herbivorous insects, but are rarely used in ecological research as a means of understanding community composition or identifying conservation constraints. Here, I first compile...

A considerable increase of the Dutch cicadellid fauna with fifteen species (Hemiptera: Auchenorrhyncha: Cicadellidae) We present 15 species of Cicadellidae new for the Netherlands: Edwardsiana bergmani, E. plebeja, E. ulmiphagus, E. ishidai, Eupteryx calcarata, E. florida, E. immaculatifrons, Fruticidia bisignata, Kybos strigilifer, Ribautiana cruc...

Agricultural intensification is one of the major threats to the biodiversity of montane and subalpine grasslands. This calls for regional agriculture policies that efficiently protect their flora and fauna without jeopardizing agricultural viability. We experimentally sought a sustainable management, testing the effects of fertilisation (slurry) an...

Identifying patterns in the effects of temperature on species' population abundances could help develop a general framework for predicting the consequences of climate change across different communities and realms. We used long-term population time series data from terrestrial, freshwater, and marine species communitieswithin central Europe to comp...

Studies of grassland communities have demonstrated that increasing vertebrate grazing decreases the diversity of specialised herbivorous insects, while plant diversity is maintained or increased. However, we still have a limited understanding of the causal mechanisms underlying these contrasting observations of two tightly linked groups of organism...

Climate change, land-use change, pollution and exploitation are among the main drivers of species’ population trends; however, their relative importance is much debated. We used a unique collection of over 1,000 local population time series in 22 communities across terrestrial, freshwater and marine realms within central Europe to compare the impac...

To maintain European semi-natural grasslands, agri-environment schemes (AES) have been established in many countries but their biodiversity benefits have remained limited. We tested the effects of three new mowing regimes designed to benefit biodiversity in extensively managed meadows across the Swiss lowlands. Our experimental treatments mimicked...

Both bottom-up (e.g. nutrients) and top-down (e.g. herbivory) forces structure plant communities, but it remains unclear how they affect the relative importance of stochastic and deterministic processes in plant community assembly. Moreover, different sized herbivores have been shown to have contrasting effects on community structure and function,...

Functional diversity (FD) metrics are increasingly used in ecological research, particularly in studies of community assembly and ecosystem functioning. However, studies using FD metrics vary greatly in the intensity by which ecological communities were sampled and it is largely unknown how sensitive these metrics are to low sampling intensity (und...

Planthoppers and leafhoppers (Auchenorryncha) are due to their high diversity, high field densities, and often strict host-plant associations an ideal bioindicator taxon for habitat quality and fragmentation. They are increasingly used for this purpose in conservation research. Switzerland, with its rich and varied landscapes, is rich in species of...

1. Habitat structure, including vegetation structural complexity, largely determines invertebrate assemblages in semi‐natural grasslands. The importance of structural complexity to the saltmarsh invertebrate community, where the interplay between vegetation characteristics and tidal inundation is key, is less well known. 2. It was hypothesised that...

European coastal salt marshes are important for the conservation of numerous species of specialist plants, invertebrates, breeding and migratory birds. When these marshes are managed for nature conservation purposes, livestock grazing is often used to counter the dominance of the tall grass Elytrigia atherica, and the subsequent decline in plant sp...

Key messages • Soil is an important habitat for thousand millions of organisms. • Soil biodiversity is extremely diverse in shapes, colours, sizes and functions. • Soil biodiversity is globally distributed, from deserts to polar regions through grasslands, forests, urban and agricultural areas. • Soil biodiversity supports many services essential t...

Livestock grazing is often recommended to preclude the development of European salt marshes into a species-poor late-successional stage that is frequently dominated by Sea couch (Elytrigia atherica). It remains unclear, however, how grazing may be optimized for conservation management in order to maintain relatively high levels of biodiversity. To...

SPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, educa...

Mühlethaler, R., Achtziger, R., Becker, L., Harms, I, Klaffke, T., Niedringhaus, R., Panassiti, B., van Klink, R. & Witsack, W. (2015): Zur Zikadenfauna des Landschafts-schutzgebiets „Königswald mit Havelseen und Seeburger Agrarlandschaft“ bei Seeburg (Brandenburg) (Hemiptera: Auchenorrhyncha). – Cicadina 15: 73-77 [ISSN (online): 2197-0335]. http...

In addition to the well-studied impacts of defecation and defoliation, large herbivores also affect plant and arthropod communities through trampling, and the associated soil compaction. Soil compaction can be expected to be particularly important on wet, fine-textured soils. Therefore, we established a full factorial experiment of defoliation (mon...

Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investi...

Capsule Breeding Meadow Pipits foraged for caterpillars and large spiders in vegetation that was less heterogeneous than vegetation at random locations.Aims To gain a better understanding of the foraging ecology of breeding Meadow Pipits on grazed coastal salt marshes, we tested three hypotheses: (1) there is a positive relation between vegetation...

Beetles and their potential for research in the terpen region Archaeo-entomological research was conducted in the investigation of Dutch ancient dwelling mounds (‘terpen’ in Friesland or ‘wierden’ in Groningen). The aim of this research was to explore its potential for shedding light on the degree of salinity and the exploitation of the erstwhile s...

Background/Question/Methods Large grazers have a major impact on their habitat, strongly affecting above- and below ground compartments of the food web. However, the exact mechanisms via which they exert such a strong influence are poorly understood. Classically, studies have focused on the aboveground impacts these large grazers have on the ecos...

a b s t r a c t This study evaluates the effects of long-term sheep grazing in salt marshes on the diversity of moths and derives conclusive management suggestions for the conservation of invertebrate diversity in salt marshes. Study sites were located on the Hamburger Hallig, on the Western coast of Schleswig–Holstein, Germany. Between 2006 and 20...

Over the last decades, biodiversity in agricultural landscapes has declined drastically. Initiatives to enhance biodiversity, such as agri‐environment schemes, often have little effect, especially in intensively farmed landscapes. The effectiveness of conservation management may be improved by scheme implementation near high‐quality habitats that c...

De soortenrijkdom van bloembezoekende insecten zoals bijen en zweefvliegen is de laatste decennia sterk afgenomen in agrarische gebieden. Initiatieven om de diversiteit te bevorderen (beheersovereenkomsten) zijn vaak niet effectief, vooral in intensief gebruikte agrarische gebieden. Mogelijk is hierbij de afstand tot potentiële brongebieden een bep...