Norbert Hölzel

University of Münster | WWU · Institute of Landscape Ecology (ILÖK)

Globally, grasslands are shaped by fire and herbivory, and grassland plants are adapted to these disturbances. However, temperate grasslands have been hotspots of land-use change, and how such changes affect interrelations between herbivory, fire and vegetation are poorly understood. Such land-use changes are widespread on the Eurasian steppe, wher...

Wildfires are relatively rare in subarctic tundra ecosystems, but they can strongly change ecosystem properties. Short-term fire effects on subarctic tundra vegetation are well documented, but long-term vegetation recovery has been studied less. The frequency of tundra fires will increase with climate warming. Understanding the long-term effects of...

Context Striking land-use changes after WW II characterize the past century in the European Alps with impact on ecosystems and biodiversity. Documenting land-use changes is often difficult due to limited information from the past. Mapping landscape history with aerial photography can foster the understanding of human-induced changes in vulnerable e...

Experimental evidence shows that grassland plant diversity enhances ecosystem functioning. Yet, the transfer of results from controlled biodiversity experiments to naturally assembled ‘real world’ ecosystems remains challenging due to environmental variation among sites , confounding biodiversity ecosystem functioning relations in observational stu...

The UN Decade on Ecosystem Restoration calls for upscaling restoration efforts, but many terrestrial restoration projects are constrained by seed availability. To overcome these constraints, wild plants are increasingly propagated on farms to produce seeds for restoration projects. During on-farm propagation, the plants face non-natural conditions...

BiCO2 - Project Soil composition changes on skid trails, resulting in altered habitats for (micro)organisms, which in turn can a ect their species composition, abundance and activity.

Coppice forests are socio-ecological systems especially rich in biodiversity. They have been transformed into high forest and abandoned across large areas of Europe over the past 200 years. Coppice loss is likely an important driver of insect declines. It is currently unclear whether habitat quality or decreasing connectivity of the remaining fragm...

Across the tree of life, organismal functional strategies form a continuum from slow-to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, the synchronization of these strategies at the entire community level is untested. We combine trait data for >2800 above-and belowground taxa from 14 tr...

Invertebrate herbivory is a crucial process contributing to the cycling of nutrients and energy in terrestrial ecosystems. While the function of herbivory can decrease with land‐use intensification, the underlying mechanisms remain unclear. We hypothesize that land‐use intensification impacts invertebrate leaf herbivory rates mainly through changes...

The UN Decade on Ecosystem Restoration calls for upscaling restoration efforts, but many terrestrial restoration projects are constrained by seed availability. To overcome these constraints, wild plants are increasingly propagated on farms to produce seeds for restoration projects. During on-farm propagation, the plants face non-natural conditions...

IntroductionDry calcareous grasslands are among the most species-rich habitats worldwide but strongly endangered by abandonment causing a severe decline of characteristic species such as orchids. To counteract further degradation, economically sustainable restoration tools such as megaherbivore grazing, that aim to substitute extinct wild grazers,...

Aim Global‐scale maps of the environment are an important source of information for researchers and decision makers. Often, these maps are created by training machine learning algorithms on field‐sampled reference data using remote sensing information as predictors. Since field samples are often sparse and clustered in geographic space, model predi...

Increasing pressure on land resources necessitates landscape management strategies that simultaneously deliver multiple benefits to numerous stakeholder groups with competing interests. Accordingly, we developed an approach that combines ecological data on all types of ecosystem services with information describing the ecosystem service priorities...

Aim Grazing intensity and fire patterns across the Eurasian steppes have changed dramatically over the past decades due to the collapse of the Soviet Union in 1991, and Kazakhstan is now a global fire hotspot. The implications of these changes for ecosystem functioning are largely unclear. We aimed to understand the effects of changed grazing inten...

Increases in land use intensity (LUI) reduce species richness. However, we have a poor understanding of how underlying coexistence mechanisms are altered by land use and whether diversity loss occurs due to changes in plant-plant interactions (competition and facilitation) or in species intrinsic growth rates. We expect that LUI could reduce stabil...

In order to communicate issues relating to the protection of plant communities and their habitats more effectively to the general public, the Floristisch-Soziologische Arbeitsgemeinschaft (FlorSoz) has proclaimed a “Plant Community of the Year” since 2019 and an explanatory text is published. This is intended to point out communities that are criti...

Understanding whether land use intensification causes regime shifts is of key importance for management, particularly if these shifts are associated with thresholds separating different ecosystem states and with hysteretic dynamics. Here we use a unique, long-term grassland database to identify thresholds in the response of 16 ecosystem functions a...

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that in...

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that in...

Den Wäldern wird sowohl hinsichtlich ihrer Kohlenstoffbindungskapazität als auch der biologischen Vielfalt eine große Bedeutung beigemessen. Die konkreten Effekte der Bewirtschaftung auf diese Faktoren sind aber noch unzureichend geklärt. Für jeden Waldbestand wird unter anderem ein Forest Management Index (ForMI, nach Kahl und Bauhus, 2014) errech...

Vor dem Hintergrund des Klimawandels und der gegenwärtigen Biodiversitätskrise kommt Wäldern als CO 2-Speicher und Habitat für viele Organismen eine hohe Bedeutung zu. Das Projekt BiCO 2 hat sich zum Ziel gesetzt, zu ermitteln, welche Effekte die forstliche Bewirtschaftung auf die Kohlenstoffspeicherkapazität und die Biodiversität haben. Als Vertre...

The impact of local biodiversity loss on ecosystem functioning is well established, but the role of larger-scale biodiversity dynamics in the delivery of ecosystem services remains poorly understood. Here we address this gap using a comprehensive dataset describing the supply of 16 cultural, regulating and provisioning ecosystem services in 150 Eur...

Restoration of terrestrial ecosystems often requires re-introduction of plants. In restored sites, the plants often face environment that differs from the one in natural populations. This which can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the...

● Plant-soil feedbacks (PSFs) underlying grassland plant richness and productivity are typically coupled with nutrient availability; however, we lack understanding of how restoration measures to increase plant diversity might affect PSFs. We examined the roles of sward disturbance, seed addition and land-use intensity (LUI) on PSFs. ● We conducted...

Soil respiration is an important pathway of soil organic carbon losses in temperate grasslands; however, it is rarely studied across broad management intensity gradients in a landscape. Using the soda-lime method, we measured in-situ soil CO 2 efflux with single measurements of long exposure time (i.e. 3 day long) in 150 grasslands in three German...

Grassland management intensity influences nutrient cycling both directly, by changing nutrient inputs and outputs from the ecosystem, and indirectly, by altering the nutrient content, and the diversity and functional composition of plant and microbial communities. However, the relative importance of these direct and indirect processes for the leach...

The goal of this study was to evaluate to what extent wild ungulates (fallow deer) can contribute to the maintenance of semi‐natural calcareous grasslands, which are a threatened habitat type (natura 2000 code *6210). In a 10‐year exclosure experiment, we tested the effects of ungulate foraging using three treatments: (A) control with combined fora...

Knowledge on the spatial distribution of land use/land cover (LULC) change is critical for developing sustainable socioeconomic and ecological pathways. Here we aimed to explore the rural landscape transformation through the analysis of LULC spatio-temporal dynamics in the entire Vietnamese Mekong Delta over the recent three decades, using Landsat...

Fires are predicted to increase in Arctic regions due to ongoing climate change. Tundra fires can alter carbon and nutrient cycling and release a substantial quantity of greenhouse gases with global consequences. Yet, the long-term effects of tundra fires on carbon (C) and nitrogen (N) stocks and cycling are still unclear. Here we used a space-for-...

Experimental evidence shows that grassland plant diversity enhances ecosystem functioning. Yet, the transfer of results from controlled biodiversity experiments to naturally assembled ‘real world’ ecosystems remains challenging. Here, we address this issue by experimentally sowing locally absent plant species in 73 agricultural grasslands along a l...

Experimental evidence shows that grassland plant diversity enhances ecosystem functioning. Yet, the transfer of results from controlled biodiversity experiments to naturally assembled ‘real world’ ecosystems remains challenging. Here, we address this issue by experimentally sowing locally absent plant species in 73 agricultural grasslands along a l...

Den Wäldern wird sowohl hinsichtlich ihrer Kohlenstoffbindungs-kapazität als auch der biologischen Vielfalt eine große Bedeutung beigemessen. Die konkreten Effekte der Bewirtschaftung auf diese Faktoren sind aber noch unzureichend geklärt. Für jeden Waldbestand wird ein Forest Management Index (ForMI,nach Kahl und Bauhus,2014) errechnet und die Eff...

Question Which vegetation and soil parameters limit species establishment in restored grasslands? Do these parameters operate predominantly on a fine or a community scale? Location White Carpathian Mountains, SE Czech Republic. Methods We compared 16 grasslands restored on former arable land with 9 well‐preserved reference grasslands. We sampled...

Grassland ecosystems provide important ecosystem services such as nutrient cycling and primary production that are affected by land-use intensity. To assess the effects of land-use intensity, operational and sensitive ecological indicators that integrate effects of grassland management on ecosystem processes such as organic matter turnover are need...

The severity of wildfires increases globally, and return intervals decrease. Fires can benefit biodiversity, as post-burn early successional stages provide diverse habitats and niches for many species. How fire disturbance affects niche use and niche overlap of species is poorly understood so far. We studied the effect of anthropogenic fire on bree...

Plant below‐ground organs perform essential functions, including water and nutrient uptake, anchorage, vegetative reproduction and recruitment of mutualistic soil microbiota. Recently, multivariate analyses showed that root traits of species can largely be linked to a ‘conservation’ and a ‘collaboration’ gradient. Here, we tested whether this speci...

Acidobacteria occur in a large variety of ecosystems worldwide and are particularly abundant and highly diverse in soils. In spite of their diversity, only few species have been characterized to date which makes Acidobacteria one of the most poorly understood phyla among the domain Bacteria. We used a culture-independent niche modeling approach to...

Fires are predicted to increase in Arctic regions due to ongoing climate change. Tundra fires can alter carbon and nutrient cycling and release a substantial amount of greenhouse gases with global consequences. Yet, the long-term effects of tundra fires on carbon (C) and nitrogen (N) stocks and cycling are still unclear. Here we used a space-for-ti...

_________________ Full text on biorxiv: https://www.biorxiv.org/content/10.1101/2020.07.17.208199v5 ___________________ Land-use intensification has contrasting effects on different ecosystem services, often leading to land-use conflicts. While multiple studies have demonstrated how landscape-scale strategies can minimise the trade-off between agr...

Restoring habitats degraded by intensive agriculture is challenging, and the resulting communities often have lower quality and host fewer species than reference ecosystems. To improve restoration outputs, we need to understand what limits both establishment and performance of target species in restored populations. In this study, we focused on gra...

Arable vegetation of calcareous soils, the plant community alliance known as Caucalidion, has been newly elected “Plant community of the Year 2022”. In this review article, we provide an overview of the Caucalidion in Germany, its species composition, life cycle and biodiversity, distribution, habitat and phytosociological variation, its history, r...

Fire shapes the world’s terrestrial ecosystems and has been influencing biodiversity patterns for millennia. Anthropogenic drivers alter fire regimes. Wildfires can amplify changes in the structure, biodiversity and functioning of the fast‐warming tundra ecosystem. However, there is little evidence available, how these fires affect species diversit...

Wildflower strips established on arable fields or intensively used grassland are an important tool for supporting biodiversity in impoverished landscapes. They provide ecosystem services like resources for pollinators, and, if they are based on perennial native plants, also plant diversity as well as nesting and wintering habitats for insects. To s...

Assessing biodiversity status and trends in plant communities is critical for understanding, quantifying and predicting the effects of global change on ecosystems. Vegetation plots record the occurrence or abundance of all plant species co‐occurring within delimited local areas. This allows species absences to be inferred, information seldom provid...

Experiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment...

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity, and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its...

Questions Herbivory is a fundamental ecological interaction underlying energy and mass flow between primary producers and consumers. The ecological theory describes plant biomass quality in terms of food for herbivores as a functional effect trait. We asked how leaf functional traits affect insect herbivory in a species-rich meadow community. Loca...

1. Plant belowground organs perform essential functions, including water and nutrient uptake, anchorage, vegetative reproduction and recruitment of mutualistic soil microbiota. Determining how belowground traits jointly determine dimensions of the trait space and how these dimensions are linked to environmental conditions would further advance our...

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...

Land‐use intensification has caused dramatic declines in grassland biodiversity, and in Europe this decline has not yet been halted. Therefore, a major challenge in ecological restoration is to effectively restore plant diversity in permanent grasslands, that is, long‐term managed grassland not being used as cropland. As species richness is often l...

The dramatic decline in the once superabundant Yellow-breasted Bunting Emberiza aureola, a widely distributed Eurasian songbird, triggered worldwidemedia interest. Five years after the initial publication, we set out to give an update on the status of this critically endangered species, the conservation actions that followed, and the lessons that c...

Seed sourcing for restoration measures is a currently highly debated issue in conservation ecology. Where to take the seeds from, if reintroduction of plant species is necessary? In many countries, seed transfer zones have been defined to preserve genetic variability and to provide locally adapted plants. However, delineation of seed transfer zones...

Fire is a major driver of global vegetation patterns. It strongly reduces litter and thus alters physical and chemical properties of the environment. Studies investigating the interplay of fire and litter are scarce, and wetland ecosystems are strongly under-represented in research focusing on litter dynamics. We present data on short-term effects...

Large and ecologically functioning steppe complexes have been lost historically across the globe, but recent land‐use changes may allow the reversal of this trend in some regions. We aimed to develop and map indicators of changing human influence using satellite imagery and historical maps, and to use these indicators to identify areas for broad‐sc...

Significance Ecosystem services derive from ecosystem functions and rely on complex interactions among a diversity of organisms. By understanding the relationships between biodiversity, ecosystem functions, and the services humans receive from nature, we can anticipate how changes in land use will affect ecosystems and human wellbeing. We show that...

Dry calcareous grasslands are one of the most species-rich habitats in the cultural landscape of Central Europe. The species richness largely resulted from the activities of humans and their livestock. Due to large-scale abandonment driven by socioeconomic changes during the last century, shrub encroachment is one of the main threats to many orchid...

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...

Zu den besonders gefährdeten Pflanzengesellschaften Deutschlands zählen Hartholz-Auenwälder (Ficario-Ulmetum, Syn.: Querco-Ulmetum), weshalb diese von der Floristisch-soziologischen Arbeits-gemeinschaft als "Pflanzengesellschaft des Jahres 2021" ausgewählt wurden. Hartholz-Auenwälder sind Laubwald-Ökosysteme der planaren und kollinen Stufe und beze...

The ability of an ecosystem to deliver multiple functions at high levels (multifunctionality) typically increases with biodiversity but there is substantial variation in the strength and direction of biodiversity effects, suggesting context-dependency. However, the drivers of this context dependency have not been identified and understood in compar...

Fire is an important disturbance in grassland ecosystems. Anthropogenic factors, especially land use, have drastically altered fire regimes in many regions, but how changing land-use intensity affects fire patterns remains weakly understood. Here, we reconstruct changes in fire regimes between 1989 and 2016 for the understudied Eurasian steppes, wh...

Unstructured citizen-science data are increasingly used for analysing the abundance and distribution of species. Here we test the usefulness of such data to predict the seasonal distribution of migratory songbirds, and to analyse patterns of migratory connectivity. We used bird occurrence data from eBird, one of the largest global citizen science d...