Niels Blaum

Niels Blaum
Universität Potsdam ·  Workgroup of Plant Ecology & Nature Conservation

Doctor of Philosophy

About

95
Publications
32,586
Reads
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2,561
Citations
Citations since 2016
47 Research Items
1882 Citations
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20162017201820192020202120220100200300400
20162017201820192020202120220100200300400

Publications

Publications (95)
Article
Full-text available
Movement of organisms is one of the key mechanisms shaping biodiversity, e.g. the distribution of genes, individuals and species in space and time. Recent technological and conceptual advances have improved our ability to assess the causes and consequences of individual movement, and led to the emergence of the new field of ‘movement ecology’. Here...
Article
In fragmented landscapes, the survival of species and the maintenance of populations with healthy genetic structures will largely depend on movement/dispersal of organisms across matrix areas. In this article, we highlight that effects of fragmentation and climate change occur simultaneously and may enhance or mitigate each other. We systematically...
Article
Full-text available
Understanding mechanisms to predict changes in plant and animal communities is a key challenge in ecology. The need to transfer knowledge gained from single species to a more generalized approach has led to the development of categorization systems where species’ similarities in life strategies and traits are classified into ecological groups (EGs)...
Article
Habitat fragmentation has major implications for demography and genetic structure of natural plant and animal populations as small and isolated populations are more prone to extinction. Therefore, many recent studies focus on spatial fragmentation. However, the temporal configuration of suitable habitat may also influence dispersal and gene flow in...
Article
Full-text available
Shrub encroachment linked to heavy grazing has dramatically changed savanna landscapes, and is a major form of rangeland degradation. Our understanding of how shrub encroachment affects arthropod communities is poor, however. Here, we investigate the effects of shrub encroachment on abundance and diversity of ground-dwelling (wingless) arthropods a...
Article
Full-text available
Context Roads are ubiquitous in human inhabited landscapes, and can impact animal movement and population dynamics, due to barrier effects, road mortality, but also by providing resources at road verges. Thus, we need a better understanding of how roads, in interaction with seasonal changes in habitat structure, affect space use and habitat selecti...
Article
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Globally, migratory ungulates are affected by fences. While field observational studies reveal the amount of animal–fence interactions across taxa, GPS tracking-based studies uncover fence effects on movement patterns and habitat selection. However, studies on the direct effects of fences and fence gaps on movement behavior, especially based on hig...
Preprint
Full-text available
Quantifying animal movements is necessary for answering a wide array of research questions in ecology and conservation biology. Consequently, ecologists have made considerable efforts to identify the best way to estimate an animal’s home range, and many methods of estimating home ranges have arisen over the past half century. Most of these methods...
Article
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Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements with...
Article
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Studies investigating the effect of aboveground herbivory on plants often use clipping to simulate the effects of herbivores, for practical reasons. However, herbivore movements and transfer of oral secretions during herbivory may cause a different response in plant physiology and morphology compared to clipping. While studies have compared effects...
Preprint
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In the last years, the emergence of zoonotic diseases and the frequency of disease outbreaks have increased substantially, fuelled by habitat encroachment and asynchrony of biological cycles due to global change. The virulence of these diseases is a key aspect for their success. In order to understand the complex processes of pathogen virulence evo...
Article
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Savannahs are often branded by livestock grazing with resulting land degradation. Holistic management of livestock was proposed to contribute to biodiversity conservation by simulating native wildlife grazing behaviour. This study attempts the comparison of the impact of a holistic management regime to a wildlife grazing management regime on grass...
Article
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In semi-arid environments characterized by erratic rainfall and scattered primary production, migratory movements are a key survival strategy of large herbivores to track resources over vast areas. Veterinary Cordon Fences (VCFs), intended to reduce wildlife-livestock disease transmission, fragment large parts of southern Africa and have limited th...
Preprint
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Context: Landscape composition and configuration, as well as seasonal landscape dynamics shape the behaviour, movement and energy expenditure in animals, i.e. foraging, hiding or fleeing, and ultimately survival. Especially in highly modified agricultural systems it is crucial to gain an understanding of how animal behaviour is influenced by landsc...
Article
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Aim: Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with de...
Preprint
Full-text available
ContextRoads are ubiquitous in human inhabited landscapes, and can impact animal movement and population dynamics, due to barrier effects, road mortality, but also by providing resources at road verges. Thus, we need a better understanding of how roads, in interaction with seasonal changes in habitat structure, affect space use and habitat selectio...
Article
Full-text available
Changing climatic conditions and unsustainable land use are major threats to savannas worldwide. Historically, many African savannas were used intensively for livestock grazing, which contributed to widespread patterns of bush encroachment across savanna systems. To reverse bush encroachment, it has been proposed to change the cattle-dominated land...
Article
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Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile...
Article
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Global change is shifting the timing of biological events, leading to temporal mis-matches between biological events and resource availability. These temporal mis-matches can threaten species' populations. Importantly, temporal mismatches not only exert strong pressures on the population dynamics of the focal species, but can also lead to substanti...
Article
Agricultural land‐use practices have intensified over the last decades, leading to population declines of various farmland species, including the European hare (Lepus europaeus). In many European countries, arable fields dominate agricultural landscapes. Compared to pastures, arable land is highly variable, resulting in a large spatial variation of...
Article
Subterranean termites create tunnels (macropores) for foraging that can influence water infiltration and may lead to preferential flow to deeper soil layers. This is particularly important in water limited ecosystems such as semi‐arid, agriculturally utilized savannas, which are particularly prone to land degradation and shrub‐encroachment. Using t...
Article
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Accurately quantifying species’ area requirements is a prerequisite for effective area‐based conservation. This typically involves collecting tracking data on species of interest and then conducting home‐range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on previous work,...
Article
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Organismal movement is ubiquitous and facilitates important ecological mechanisms that drive community and meta-community composition and hence biodiversity. In most existing ecological theories and models in biodiversity research, movement is represented simplistically, ignoring the behavioural basis of movement and consequently the variation in b...
Article
Many semi‐arid savannas are prone to degradation, caused for example, by overgrazing or extreme climatic events, which often lead to shrub encroachment. Overgrazing by livestock affects vegetation and infiltration processes by directly altering plant composition (selective grazing) or by impacting soil physical properties (trampling). Water infiltr...
Article
Macropores created by invertebrates improve ecosystem functions such as soil properties and hydrological processes. In semi-arid savannas, where water is the main limiting resource and precipitation is scarce macropores might increase infiltration, and thereby improve water availability for plants. Macropores may therefore represent a buffering mec...
Article
Agricultural landscapes are spatially and temporally dynamic habitats that force wildlife to interact with different management practices, such as harvests and mowing events which cause sudden changes in resource availability. Animals may avoid agricultural management events and the changed habitat, to search for undisturbed areas or they might use...
Article
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Introduction: Many semiarid regions around the world are presently experiencing significant changes in both climatic conditions and vegetation. This includes a disturbed coexistence between grasses and bushes also known as bush encroachment, and altered precipitation patterns with larger rain events. Fewer, more intense precipitation events might p...
Article
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Context Human land use intensified over the last century and simultaneously, extreme weather events have become more frequent. However, little is known about the interplay between habitat structure, direct short-term weather effects and indirect seasonal effects on animal space use and behavior. Objectives We used the European hare (Lepus europaeu...
Preprint
Full-text available
Organismal movement is ubiquitous and facilitates important ecological mechanisms that drive community and metacommunity composition and hence biodiversity. In most existing ecological theories and models in biodiversity research, movement is represented simplistically, ignoring the behavioural basis of movement and consequently the variation in be...
Article
Full-text available
Accurately quantifying species' area requirements is a prerequisite for effective area-based conservation. This typically involves collecting tracking data on species of interest and then conducting home-range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on the previous w...
Article
1.Understanding the drivers underlying disease dynamics is still a major challenge in disease ecology, especially in the case of long‐term disease persistence. Even though there is a strong consensus that density‐dependent factors play an important role for the spread of diseases, the main drivers are still discussed and, more importantly, might di...
Article
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Semiarid woodlands and savannas are globally important biomes that provide ecosystem goods and services such as habitat for biota and sinks for carbon, support millions of people that rely primarily on pastoralism, and supply livelihoods for about a third of the global human population. Savannas, however, are prone to degradation by overgrazing, an...
Article
Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently the question of which home range estimator to use on modern, highly autoco...
Article
Full-text available
Agricultural land-use practices have intensified over the last decades, leading to population declines of various farmland species, including the European hare (Lepus eu-ropaeus). In many European countries, arable fields dominate agricultural landscapes. Compared to pastures, arable land is highly variable, resulting in a large spatial variation o...
Article
Full-text available
Context Movement is one of the key mechanisms for animals to deal with changes within their habitats. Therefore, resource variability can impact animals’ home range formation, especially in spatially and temporally highly dynamic landscapes, such as farmland. However, the movement response to resource variability might depend on the underlying land...
Cover Page
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Front Cover: A GPS-collared European hare (Lepus europaeus) in a barley field. During the last decades, hare populations have declined due to agricultural intensification. Vegetation height and agricultural field size are important factors affecting habitat selection by hares in arable landscapes. Thus, increasing landscape heterogeneity can increa...
Article
Understanding vegetation–modern pollen relationships is essential to provide confidence in fossil pollen reconstructions of long-term vegetation changes in savanna ecosystems. In this paper we compare the taxonomical composition and the diversity (Hill N0, N1, N2) of vegetation and modern pollen along precipitation and local grazing-intensity gradi...
Article
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Restrictions on roaming Until the past century or so, the movement of wild animals was relatively unrestricted, and their travels contributed substantially to ecological processes. As humans have increasingly altered natural habitats, natural animal movements have been restricted. Tucker et al. examined GPS locations for more than 50 species. In ge...
Article
Across the planet, grass-dominated biomes are experiencing shrub encroachment driven by atmospheric CO2 enrichment and land-use change. By altering resource structure and availability, shrub encroachment may have important impacts on vertebrate communities. We sought to determine the magnitude and variability of these effects across climatic gradie...
Article
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Soil erosion, while often studied in dryland settings for rural regions, has only occasionally been studied in urban settings. This study maps and quantifies areal extent and severity of water erosion in a dryland city (Windhoek, Namibia) using a snap-shot field survey approach. The results show that nearly 56% of the city could be affected by wate...
Article
Xu et al. (2016) recently demonstrated the existence of three ecosystem states in the tropics: forest, savanna and ‘treeless’. Using remotely sensed tree cover and canopy height measurements, they conclude that 1) savannas and forest represent alternative states due to their climatic overlap in moist conditions (1,500-2,000 mm mean annual precipita...
Article
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The study compared abundance and diversity of small mammals between a commercial livestock and neighbouring game farm in the Kalahari Thornveld of Namibia’s Omaheke region. Sherman traps baited with standard small-mammal attractants were set out in grids in similar habitats on each land use for four trap-nights during the growing season and the non...
Chapter
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Die Ausbreitung und Zunahme holziger Vegetation in grasdominierten Ökosystemen Afrikas ist ein weit verbreitetes Phänomen mit häufig negativen ökologischen und ökonomischen Auswirkungen. Die Ursachen sind vielfältig und in der Regel anthropogen. Der Klimawandel und insbesondere steigende atmosphärische CO2-Gehalte scheinen globale Treiber, welche d...
Article
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Accelerated soil water erosion is one of the major global environmental problems that adversely affect both rural and urban areas. While many investigations have been initiated to efficiently understand and effectively manage water erosion problems in agricultural areas, specific knowledge on urban water erosion is less pronounced. This paper aims...
Article
Military areas are valuable habitats and refuges for rare and endangered plants and animals. We developed a new approach applying innovative methods of hyperspectral remote sensing to bridge the existing gap between remote sensing technology and the demands of the nature conservation community. Remote sensing has already proven to be a valuable mon...
Presentation
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Understanding the underlying processes in occurrence, abundance and diversity of species is important to predict future patterns of species diversity in changing environments. In arid and semi-arid savannas, heavy land use impacts and changes in climate substantially affect habitat composition. In particular, pristine savannas areas dominated by gr...
Article
Savanna rangelands worldwide are threatened by shrub encroachment, i.e. the increase of woody plant species at the cost of perennial grasses, causing a strong decline in the productivity of domestic livestock production. Although recent studies indicate that fire might be of great importance for semi-arid and arid savanna dynamics, it is largely no...
Article
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Improving our understanding of biodiversity and ecosystem functioning and our capacity to inform ecosystem management requires an integrated framework for functional biodiversity research (FBR). However, adequate integration among empirical approaches (monitoring and experimental) and modelling has rarely been achieved in FBR. We offer an appraisal...
Article
1. The complex, nonlinear response of dryland systems to grazing and climatic variations is a challenge to management of these lands. Predicted climatic changes will impact the desertification of drylands under domestic livestock production. Consequently, there is an urgent need to understand the response of drylands to grazing under climate change...
Article
In this field experiment we investigate the impact of land use induced savanna degradation on movement behaviour of the spotted sand lizard (Pedioplanis l. lineoocellata) in the southern Kalahari. Foraging behaviour of lizards was tested in a factorial design (low vs. high prey availability) in degraded and non-degraded habitats. An interaction bet...
Article
While several empirical and theoretical studies have clearly shown the negative effects of climate or landscape changes on population and species survival only few of them addressed combined and correlated consequences of these key environmental drivers. This also includes positive landscape changes such as active habitat management and restoration...
Poster
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Monitoring animal behaviour in dynamic environments such as agricultural landscapes is crucial to understand impacts of current farming practices such as time of mowing, harvest or use of pesticides, and land use changes such as homogenisation of arable crops or energy crops. Continuous recording of animal movement behaviour is challenging since ma...
Article
ABSTRACT We analyzed relative sensitivities of small- and medium-sized carnivores to livestock husbandry (stocking rates and predator control) in Kalahari, South Africa, rangelands at a regional scale. We monitored small carnivores using track counts on 22 Kalahari farms across a land-use gradient ranging from low to high stocking rates and also in...