Norbert HölzelUniversity of Münster | WWU · Institute of Landscape Ecology (ILÖK)
Norbert Hölzel
Prof. Dr. Dr. h. c.
About
298
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Introduction
Since 2007 I am professor for biodiversity and ecosystem research at the University of Münster leading a group of > 20 people focussing on community and ecosystem ecology, biodiversity research, global change ecology and ecological restoration . Current projects are funded by the DFG (Bioiversity Exploratories) and the BMBF (Sustainable Land Management). I am associated editor of Applied Vegetation Science and Flora.
Additional affiliations
October 2007 - present
October 2005 - September 2007
May 1996 - May 2005
Education
November 1991 - January 1995
Publications
Publications (298)
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 stud...
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...
Peatlands play a key role in climate change mitigation strategies and provide multiple ecosystem services, presuming near natural, waterlogged conditions. However, there is a lack of knowledge on how spatially heterogeneous changes in climate across Europe, such as the predicted increase in drought frequency in Central Europe, might affect these ec...
Seed rain, the amount of seeds reaching an area via primary or secondary dispersal, affects the regeneration of plant communities and shapes the trajectory of future community composition. In agricultural grasslands, the composition and density in seed rain are mainly driven by land use, but drivers of seed rain quality and quantity along land-use...
Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in...
Shifts in fire regimes can trigger rapid changes in ecosystem functioning and biodiversity. We synthesize evidence for patterns, causes and consequences of recent change in fire regimes across the Eurasian steppes, a neglected global fire hotspot. Political and economic turmoil following the break-up of the Soviet Union in 1991 triggered abrupt lan...
Für die Zukunft von Wäldern und ihren ökosystemaren Leistungen ist es von entscheidender Bedeutung, bei forstlichen Maßnahmen ihre Funktion als ober- und unterirdischer Kohlenstoffspeicher ebenso zu berücksichtigen wie ihre Relevanz als Lebensraum für eine Vielzahl waldtypischer Arten. Diese Beziehungen untersucht das BiCO2-Projekt im Verbund aus W...
Earth harbours an extraordinary plant phenotypic diversity¹ that is at risk from ongoing global changes2,3. However, it remains unknown how increasing aridity and livestock grazing pressure—two major drivers of global change4–6—shape the trait covariation that underlies plant phenotypic diversity1,7. Here we assessed how covariation among 20 chemic...
Mineral-associated organic carbon (MAOC) constitutes a major fraction of global soil carbon and is assumed less sensitive to climate than particulate organic carbon (POC) due to protection by minerals. Despite its importance for long-term carbon storage, the response of MAOC to changing climates in drylands, which cover more than 40% of the global...
Migratory animals rely on multiple sites during their annual cycles. Deteriorating conditions at any site can have population-level consequences, with long-distance migrants seen as especially susceptible to such changes. Reduced adult survival caused by persecution at non-breeding sites has been suggested a major reason for the catastrophic declin...
Skid trails are a major management‐induced disturbance in temperate forest ecosystems with considerable impact on soil ecological processes that are so far poorly understood. In German forests, skid trails comprise 10%–20% of the forest area that is potentially affected by soil compaction through heavy machinery. We systematically investigated the...
Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in dryla...
Plant biomass is a fundamental ecosystem attribute that is sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant biomass in the Arctic is logistically challenging and resource intensive. Lack of accessible field data hinders efforts to understand the amount, composition, distribution, and changes in plant biomas...
Restoration of terrestrial ecosystems often requires re‐introduction of plants. In restored sites, the plants often face environments that differ from those of natural populations. This can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the novel co...
Organismal functional strategies form a continuum from slow- to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, whether there is synchronisation of these strategies at the entire community level is unclear. Here, we combine trait data for >2800 above- and belowground taxa from 14 trophic...
Biodiversity typically increases multiple ecosystem functions simultaneously (multifunctionality) but variation in the strength and direction of biodiversity effects between studies suggests context dependency. To determine how different factors modulate the diversity effect on multifunctionality, we established a large grassland experiment manipul...
European inner-alpine dry grasslands face substantial threats within the increasingly human-altered landscape, endangering their persistence. To understand changes in dry grassland communities, we revisited historical vegetation plots of Josias Braun-Blanquet after 70 years in Val Venosta, Italy, hosting rare steppe-like grassland vegetation. By di...
Since 2019 the ‘Floristisch-soziologische Arbeitsgemeinschaft’ (FlorSoz) has annually nominated the ‘plant community of the year’, to draw attention to Germany’s endangered plant communities in need of protection. This campaign specifically aims at supporting the conservation of plant communities and their habitats as well as at promoting political...
Many grassland ecosystems and their associated biodiversity depend on the interactions between fire and land‐use, both of which are shaped by socioeconomic conditions. The Eurasian steppe biome, much of it situated in Kazakhstan, contains 10% of the world's remaining grasslands. The break‐up of the Soviet Union in 1991, widespread land abandonment...
Wälder bieten durch ihren komplexen Aufbau und ihre Strukturvielfalt einer großen Zahl an Pflanzen- und Tierarten einen Lebensraum. Ein Teilvorhaben des BiCO2-Projektes ist es, herauszufinden, wie sich die Bewirtschaftung auf die Individuen- und Artenzahl ausgewählter Artengruppen auswirkt, wobei der Fokus in diesem Artikel auf den Vögeln, Käfern,...
Im BiCO2-Projekt untersuchte ein Teilvorhaben den Einfluss der Waldbewirtschaftung auf bodenökologische Prozesse. Dazu wurden auf insgesamt 200 Flächen in vier Untersuchungsgebieten umfangreiche bodenphysikalische, -chemische und mikrobiologische Analysen sowie Humusformenbeschreibungen durchgeführt. Neben dem Einfluss der Waldnutzungsintensität au...
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...
Introduction
Dry 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 a di...
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...
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...
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...
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...
Motivation
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 se...