Land use and biodiversity

Land use is a main driver of biodiversity loss and this has been documented in numerous studies. We focus on three main research questions:

What are the main land use drivers of biodiversity change, i.e. what components of human land use are detrimental to species, and which ones have little effect?
How does land use interact with climate in influencing the populations of species? Climate is known to affect many species, in particular insects, and the open question is how these drivers interact in causing, for example, insect decline.
How can we adapt land use to have less negative effects on species?

We investigate human land use in agricultural systems, in grasslands, in forests, and in the city (see research topic Urban Ecology). We monitor biodiversity of animals in the field, quantifying the populations of insects, birds, and other organisms, and linking their dynamics to variables describing land use in the system investigated. To identify species, we use classic methods as well as modern methodology (audiorecording of birds, insect metabarcoding, AI-identification of insect pictures). Importantly, we conduct experiments where land use is manipulated, either by us or by farmers or foresters, to mechanically understand the role of biodiversity drivers.

Questions 1-3 are investigated in a number of projects:

Biodiversity Exploratories (see also separate web page)

The Biodiversity Exploratories are a long-term priority program funded by the German Science Foundation (DFG). The project focusses on land use, biodiversity and ecosystem functioning in grassland and forests. Between 35 and 45 research groups from all over Germany use this platform for biodiversity research. We have been involved in this project since its beginning¹.

Plots have been established in three regions in Germany, in the Schwabian Alb, Schorfheide-Chorin and in the Hainich. We coordinate research in the 100 plots of the Hainich Exploratory. Our Local Management Team (LMT) is based in Mülverstedt in Thuringia, and acts as an interface between the scientists, and local stakeholders and land owners.

Since 2008 we study the Arthropods in all 300 grasslands and forests plots. Arthropods contribute significantly to the maintenance of terrestrial ecosystems and provide a variety of ecosystem services. We identified a decline of arthropods related to land use² in the surroundings as well as drivers of change in forests³. The long-term nature of this time series, which is unique worldwide, now also allows disentangling the relative role of weather and land use changes in the arthropod community. See the separate page of the Arthropods time-series for more description of the time series.

Within the framework of the Biodiversity Exploratories we develop methods for AI-driven identification of insects. In the project AIforIBM (Artificial Intelligence for automated Insect Biodiversity Monitoring), we cooperate with the Technical University Ilmenau (who developed Flora Incognita) to train an AI to identify insects.

Our group is also responsible for the coordination of the BELongDead experiment that takes place in the 30 “VIP” (very intensive plots) in the three Biodiversity Exploratories. Initiated by Ernst-Detlef Schulze of the Max-Planck-Institute of Biogeochemistry in Jena, logs (diameter 30-40cm, length 4m) of 13 different tree species were placed in triplicate in each of the plots in 2008. Since then we study insect colonization of these logs using emergence traps. Other groups study fungi, mites, other organisms or log decomposition, e.g. DOC flow. This unique experiment allows disentangling the effect of tree species from the effect of the surrounding forest in shaping the communities using deadwood and also decomposition. Important results concern the analysis of species-specific differences in the decay of the logs over time⁴, and the development of the insect communities over time⁵.

Douglas-Fir and biodiversity of beech forests

Germany's forests face unprecedented challenges due to drought-induced tree mortality, highlighting the urgent need for adaptive forestry practices in the face of climate change. In the project “Future Potential of Douglas Fir and Silver Fir Mixture” (TUM, University of Göttingen, with support from the Bavarian State Institute of Forestry (LWF)), we examine the ecological implications of incorporating Douglas fir and silver fir into beech forests.

Our primary goal is to understand the impact of these mixed stands on native biodiversity, specifically focusing on taxonomic and functional diversity within communities of birds, bats, and insects. In a review, we found that previous studies have found little effects of Douglas fir introduction on biodiversity, but also that the number of studies is very limited⁶. We selected 63 plots (30 Douglas-fir-beech, 23 silver fir-beech, and 10 beech plots as control) in Lower Franconia (Spessart) in 2023. The mixture plots represent a gradient of conifer proportions within the beech stands. We use malaise and light traps to measure biomass and species richness of arthropods and nocturnal moths, and deploy audio recorders to monitor bird and bats. In addition, we monitor bird reproductive success using nestboxes.

Completed projects:

Spongy moth outbreaks and forest biodiversity (completed 2023)

Every year, the control of spongy moths in mixed oak forests is the subject of public debate when they reproduce en masse. On the one hand, high densities of spongy moth caterpillars can lead to defoliation of oak and other tree species. This should be prevented by timely control measures to protect forest owners from damage and even destruction of their stands. On the other hand, mixed oak forests are very species-rich and home to a large number of endangered butterflies, moths, birds and other species, so there is concern that these will suffer in the short or long term from the use of insecticides. However, the spongy moth outbreak itself also has negative consequences for other species in an oak forest, as the species community is dominated by a single species, the pest, for some time. While the biology of the spongy moth is well known and there are already many good studies on the effects of defoliation on oak trees, there are still some gaps in our knowledge that are important for risk management, e.g. with regard to the short- and long-term effects of the spongy moth on oak growth depending on the location. The interactions between spongy moth densities, site conditions, the chosen management approach and the responses of oak forests and their communities can only be investigated in years of mass reproduction. A major success of the project was to set up a unique experiment with experimental spraying of forest stands by helicopter, to disentangle the effects of gypsy moth density and insecticide use⁶. A major result of the project is that while there are significant side-effect on other insects of both insecticide use and spongy moth outbreak, the effects vanished more or less after 1-2 years. Similarly, the spongy moth outbreak affected oak growth, but the effect faded also after 1-2 years and tree mortality was, so far, not significantly enhanced. A conclusion from the project is thus that it would probably more more effective to compensate forest owners for the (rare) event of trees dying, rather than to spend large sums of money spraying forests with helicopters. See Leroy et al. 2022 and 2023 for some of the effects on other insects.

Biodiversity in mixed beech forests (completed 2021)

In the past, studies on biodiversity in forests were mainly conducted in unmanaged forests. However, the majority of forest land in Germany is used for forestry. Integrative forestry aims to coordinate the use and protection of biodiversity, thereby enabling the preservation of species diversity across the entire forest area. Integrative forest management includes measures such as promoting biotope wood structures in the form of habitat trees and deadwood, designating stepping stone areas and preserving special sites with specific biodiversity. The project ‘Biodiversity in mixed beech forests’ helped to provide the scientific foundations for decision-making processes that have an impact on biodiversity in the course of forest management. Pure beech forests were compared with stands where beech was mixed with other species, such as spruce, oak, or other species. In addition, the role of small protected areas was considered. A key publication by the PhD-student Jan Leidinger showed the effects of different admixtures on biodiversity in the forests¹⁰.

Brazilian grasslands (completed 2016)

Land-use changes such as conversion of semi-natural grasslands to agriculture, silviculture, or high-intensity pastures affect biodiversity and ecosystem functions and services. However, which ecosystem functions are affected when highly diverse grasslands are converted remains largely unknown. As a model system, we studied 80 grasslands in Rio Grande do Sul, southern Brazil, comprising exceptionally diverse permanent grasslands that are traditionally managed with burning of accumulated biomass and moderate grazing, and four additional grassland types with different present or historical management: Permanent grasslands with reduced or increased current management intensity and secondary grasslands after past agricultural or silvicultural use. We measured ten ecosystem functions covering all major below- and aboveground ecosystem components and the processes that link them, using the novel rapid ecosystem function assessment approach developed in our group. See Leidinger et al. 2015¹¹.

BIOLOG Diva-Jena (completed 2009)

The collaborative BIOLOG DIVA-Jena research project 'The relationship between Biodiversity and Ecosystem Functioning in Grassland Ecosystems' funded by the German Federal Ministry of Education and Research (BMBF) between 2000 and 2010 used extensively managed grasslands in the states of Thuringia and Bavaria as model ecosystems, to study the relationship between biodiversity and ecosystem functioning. Using a gradient in plant species richness a finding of the project was that there was a relationship between plant species richness and ecosystem variables also in these semi-natural ecosystems¹².

Agripopes (completed 2010)

The importance of land-use intensity for biodiversity and ecosystem functioning was also the focus of the AGRIPOPES project, an ESF-funded network of 12 research teams across Europe. Using European agroecosystems, in particular wheat fields, as a model ecosystem, the project analyzed the effects of land use intensification parameters on biodiversity and the biocontrol potential of biodiversity. In a unique approach, more than 1300 wheat fields across were assessed and information about land use, biodiversity and ecosystem functioning were assembled. In a very highly-cited publication the project showed that the use of plant protection products, in particular insecticide and herbicide, were more important for biodiversity reduction of insects, plants and birds as well as the biocontrol potential in the sites than other measures of land use¹³.

¹Fischer, M., O. Bossdorf, S. Gockel, F. Hänsel, A. Hemp, D. Hessenmöller, G. Korte, J. Nieschulze, S. Pfeiffer, D. Prati, S. Renner, I. Schöning, U. Schumacher, K. Wells, F. Buscot, E. K. V. Kalko, K. E. Linsenmair, E.-D. Schulze, and W. W. Weisser. 2010. Implementing large-scale and long-term functional biodiversity research: The Biodiversity Exploratories. Basic and Applied Ecology 11:473-485.

²Seibold, S., M. M. Gossner, N. K. Simons, N. Blüthgen, J. Müller, D. Ambarlı, C. Ammer, J. Bauhus, M. Fischer, J. C. Habel, K. E. Linsenmair, T. Nauss, C. Penone, D. Prati, P. Schall, E.-D. Schulze, J. Vogt, S. Wöllauer, and W. W. Weisser. 2019. Arthropod decline in grasslands and forests is associated with landscape-level drivers. Nature 574:671-674.

³Staab, M., M. M. Gossner, N. K. Simons, R. Achury, D. Ambarlı, S. Bae, P. Schall, W. W. Weisser, and N. Blüthgen. 2023. Insect decline in forests depends on species’ traits and may be mitigated by management. Communications Biology 6.

⁴Edelmann, P., W. W. Weisser, D. Ambarli, C. Bässler, F. Buscot, M. Hofrichter, B. Hoppe, H. Kellner, C. Minnich, J. Moll, D. Persoh, S. Seibold, C. Seilwinder, E. D. Schulze, S. Wöllauer, and W. Borken. 2023. Regional variation in deadwood decay of 13 tree species: Effects of climate, soil and forest structure. Forest Ecology and Management 541.

⁵Seibold, S., W. W. Weisser, D. Ambarli, M. M. Gossner, A. S. Mori, M. W. Cadotte, J. Hagge, C. Bässler, and S. Thorn. 2023. Drivers of community assembly change during succession in wood-decomposing beetle communities. Journal of Animal Ecology 92:965-978.

⁶Leroy, B. M. L., H. Lemme, P. Braumiller, T. Hilmers, M. Jacobs, S. Hochrein, S. Kienlein, J. Müller, H. Pretzsch, K. Stimm, S. Seibold, J. Jaworek, W. A. Hahn, S. Müller‐Kroehling, and W. W. Weisser. 2021. Relative impacts of gypsy moth outbreaks and insecticide treatments on forest resources and ecosystems: An experimental approach. Ecological Solutions and Evidence 2.

⁷Graf, M., R. Achury, I. Lanzrein, R. Wenglein, P. Annighöfer, S. Scheu, and W. W. Weisser. 2025. The effect of Douglas-fir on biodiversity in European forests – What do we know and what do we not know? Forest Ecosystems 13:100319.

⁸Leroy, B. M. L., D. Rabl, M. Püls, S. Hochrein, S. Bae, J. Müller, P. D. N. Hebert, M. L. Kuzmina, E. V. Zakharov, H. Lemme, W. A. Hahn, T. Hilmers, M. Jacobs, S. Kienlein, H. Pretzsch, L. Heidrich, S. Seibold, N. Roth, S. Vogel, P. Kriegel, and W. W. Weisser. 2023. Trait-mediated responses of caterpillar communities to spongy moth outbreaks and subsequent tebufenozide treatments. Ecological Applications 33.

⁹Leroy, B. M. L., S. Seibold, J. Morinière, V. Bozicevic, J. Jaworek, N. Roth, S. Vogel, S. Zytynska, R. Petercord, P. Eichel, and W. W. Weisser. 2022. Metabarcoding of canopy arthropods reveals negative impacts of forestry insecticides on community structure across multiple taxa. Journal of Applied Ecology 59:997-1012.

¹⁰Leidinger, J., M. Blaschke, M. Ehrhardt, A. Fischer, M. M. Gossner, K. Jung, S. Kienlein, J. Kozak, B. Michler, R. Mosandl, S. Seibold, K. Wehner, and W. W. Weisser. 2021. Shifting tree species composition affects biodiversity of multiple taxa in Central European forests. Forest Ecology and Management 498:119552.

¹¹Leidinger, J. L., M. M. Gossner, W. W. Weisser, C. Koch, Z. L. Rosadio Cayllahua, L. R. Podgaiski, M. M. Duarte, A. S. Araújo, G. E. Overbeck, J. M. Hermann, J. Kollmann, and S. T. Meyer. 2017. Historical and recent land use affects ecosystem functions in subtropical grasslands in Brazil. Ecosphere 8:e02032.

¹²Unsicker, S. B., A. Franzke, J. Specht, G. Kohler, J. Linz, C. Renker, C. Stein, and W. W. Weisser. 2010. Plant species richness in montane grasslands affects the fitness of a generalist grasshopper species. Ecology 91:1083-1091.

¹³Geiger, F., J. Bengtsson, F. Berendse, W. W. Weisser, M. Emmerson, M. B. Morales, P. Ceryngier, J. Liira, T. Tscharntke, C. Winqvist, S. Eggers, R. Bommarco, T. Pärt, V. Bretagnolle, M. Plantegenest, L. W. Clement, C. Dennis, C. Palmer, J. J. Oñate, I. Guerrero, V. Hawro, T. Aavik, C. Thies, A. Flohre, S. Hänke, C. Fischer, P. W. Goedhart, and P. Inchausti. 2010. Persistent negative effects of pesticides on biodiversity and biological control potential on European farmland. Basic and Applied Ecology 11:97-105.