Jens-Christian Svenning

Aarhus University | AU · Department of Biology

Trophic rewilding is proposed as an effective approach to tackle biodiversity loss by restoring ecosystem dynamics through the reintroduction of large-bodied animals. Currently, evidence on the effectiveness of reintroduction programs is sparse and difficult to generalize. To better understand the ecological consequences of trophic rewilding, we si...

Expanding and intensifying anthropogenic land use is one of the greatest drivers of changes of biodiversity loss and political inequality worldwide. In the Greater Mara, Kenya, a trend of private land enclosure is currently happening, led by smallholders wishing to protect and uphold their land titles. Here we expand on previous work by Løvschal et...

Safeguarding Earth’s tree diversity is a conservation priority due to the importance of trees for biodiversity and ecosystem functions and services such as carbon sequestration. Here, we improve the foundation for effective conservation of global tree diversity by analyzing a recently developed database of tree species covering 46,752 species. We q...

The Darwinian shortfall, i.e. the lack of knowledge of phylogenetic relationships, significantly impedes our understanding of evolutionary drivers of global patterns of biodiversity. Spatial bias in the Darwinian shortfall, where phylogenetic knowledge in some regions is more complete than others, could undermine eco‐ and biogeographic inferences....

Human activities are causing massive increases in extinction rates but might also lead to drastic increases in speciation rates; for example, after human‐mediated spread of species to otherwise unreachable landmasses. The long‐term net anthropogenic effects on biodiversity therefore remain uncertain. Our aim was to assess the combined anthropogenic...

Islands frequently harbour unique assemblages of species, yet their ecological roles and differences are largely ignored in island biogeography studies. Here, we examine eco‐evolutionary processes structuring mammal assemblages on oceanic islands worldwide, including all extant and extinct late‐Quaternary mammal species. We find island mammal assem...

1. Determining the patterns and drivers of the small‐scale species‐area relationship (SAR) is crucial for improving our understanding of community assembly and biodiversity patterns. Niche‐based and stochastic processes are two principal categories of mechanisms potentially driving SARs. However, their relative importance has rarely been quantified...

Archaeological and palaeontological records offer tremendous yet often untapped potential for examining long-term biodiversity trends and the impact of climate change and human activity on ecosystems. Yet zooarchaeological and fossil remains suffer various limitations, including that they are often highly fragmented and morphologically unidentifiab...

Addressing global environmental challenges requires access to biodiversity data across wide spatial, temporal and taxonomic scales. Availability of such data has increased exponentially recently with the proliferation of biodiversity databases. However, heterogeneous coverage, protocols, and standards have hampered integration among these databases...

Large-diameter trees regulate forest diversity, structure and aboveground biomass (AGB), but the mechanisms 15 whereby they control forest processes remain understudied, especially in early successional forests. We used 1,956 0.16 ha plots from the Korean National Forest Inventory from mostly 20-50 years old stands (biomass accumulation phase) in c...

Humans have reshaped the distribution of biodiversity across the globe, extirpating species from regions otherwise suitable and restricting populations to a subset of their original ranges. Here, we ask if anthropogenic range contractions since the Late Pleistocene led to an under‐representation of the realized niches for megafauna, an emblematic g...

Two major environmental challenges of our time are responding to climate change and reversing biodiversity decline. Interventions that simultaneously tackle both challenges are highly desirable. To date, most studies aiming to find synergistic interventions for these two challenges have focused on protecting or restoring vegetation and soils but ov...

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknow...

Areas of endemism are a standard unit of biogeography and are commonly used for analytical biogeographic analyses as a criterion to identify areas for conservation. Galianthe is a genus of 56 species of mainly herbaceous plants from the family Rubiaceae found in the Neotropics, occurring in campos rupestres (quartzitic rock outcrops), cerrado (sava...

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknow...

Assemblages of large mammal species play a disproportionate role in the structure and composition of natural habitats. Loss of these assemblages destabilizes natural systems, while their recovery can restore ecological integrity. Here we take an ecoregion-based approach to identify landscapes that retain their historically present large mammal asse...

With novel ecosystems becoming the norm, it is increasingly necessary to re‐evaluate what is meant by “restoration”. An important aspect of this concept is what we define to be native and, by extension, alien. In order to better prioritize restoration projects, we have here devised a classification system of ten, graduated terms that describe inter...

The savannas of the Kenya-Tanzania borderland cover >100,000 km 2 and is one of the most important regions globally for biodiversity conservation, particularly large mammals. The region also supports >1 million pastoralists and their livestock. In these systems, resources for both large mammals and pastoralists are highly variable in space and time...

Seed dispersal in decline Most plant species depend on animals to disperse their seeds, but this vital function is threatened by the declines in animal populations, limiting the potential for plants to adapt to climate change by shifting their ranges. Using data from more than 400 networks of seed dispersal interactions, Fricke et al . quantified t...

Quantifying anthropogenic climate change vulnerability is essential for estimating the risk of species extinction and developing conservation strategies. The Magnolia genus is widespread in the Americas and Asia, with nearly half of species currently threatened. Here, we used climate-niche factor analysis to study the vulnerability of Magnolia spec...

We review palaeoenvironmental proxies and combinations of these relevant for understanding hunter-gatherer niche construction activities in pre-agricultural Europe. Our approach consists of two steps: (1) identify the possible range of hunter-gatherer impacts on landscapes based on ethnographic studies; (2) evaluate proxies possibly reflecting thes...

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion...

Tree cover, which has been widely studied using various remote sensing techniques, serves an essential indicator of forest productivity and habitat quality. Spatial heterogeneity in tree cover has received less attention despite links with critical phenomena such as biodiversity, tree re-expansion into formerly deforested areas, and degradation of...

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...

Aims The rapid increase in the number of species that have naturalized beyond their native range is among the most apparent features of the Anthropocene. How alien species will respond to other processes of future global changes is an emerging concern and remains poorly misunderstood. We therefore ask whether naturalized species will respond to cli...

To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed...

Natural environments have been associated with mental health benefits, but globally access to these benefits is threatened by urban development and densification. However, it remains unclear how natural environments relate to mental health and how consistent the association is across populations. Here we use a life-course approach with a population...

There is growing interest in aligning the wildlife conservation and restoration agenda with climate change mitigation goals. However, the presence of large herbivores tends to reduce aboveground biomass in some open-canopy ecosystems, leading to the possibility that large herbivore restoration may negatively influence ecosystem carbon storage. Belo...

Large herbivores provide key ecosystem processes, but have experienced massive historical losses and are under intense pressure, leaving current ecosystems with dramatically simplified faunas relative to the long‐term evolutionary norm. Hampered by a shifting baseline, natural levels of large‐herbivore biomass are poorly understood and seldom targe...

Ecological processes and biodiversity patterns are strongly affected by how animals move through the landscape. However, it remains challenging to predict animal movement and space use. Here we present our new r package enerscape to quantify and predict animal movement in real landscapes based on energy expenditure. enerscape integrates a general l...

The potential for megafauna restoration is unevenly distributed across the world, along with the socio‐political capacity of countries to support these restoration initiatives. We show that choosing a recent baseline to identify species' indigenous range puts a higher burden for megafauna restoration on countries in the Global South, which also hav...

The tropical conservatism hypothesis (TCH) posits that the latitudinal gradient in biological diversity arises because most extant clades of animals and plants originated when tropical environments were more widespread and because the colonization of colder and more seasonal temperate environments is limited by the phylogenetically conserved enviro...

Mediterranean mountain landscapes are undergoing a widespread phenomenon of abandonment. This brings, as a consequence, the loss of traditional land use practices, such as transhumant pastoralism, as well as shrub and wood encroachment, with repercussions on the biodiversity associated with semi-open, human-managed landscapes. In this study, we foc...

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...

Understanding the driving factors of soil multifunctionality is of great significance for the protection and restoration of degraded terrestrial ecosystems. However, the effects of above- and belowground factors are rarely evaluated simultaneously, and the driving mode of both factors on soil multifunctionality is not clear. Here, we evaluated rest...

Aim Understanding how biotic communities are spatially distributed is essential for biodiversity conservation in human-modified landscapes. The large-scale subsidence wetlands generated by underground coal mining in China have been increasingly used by large numbers of waterbirds, which remain understudied. We aimed to explore the role of non-rando...

Aim: Differences in physiography have been proposed to explain the diversity anomaly for vascular plants between environmentally similar regions of eastern Asia (EAS) and eastern North America (ENA). Here, we use plant species within disjunct genera to examine whether differences in topography contribute to the diversity anomaly and whether the ric...

Questions Can multi-decadal vegetation changes in a decommissioned brown coal mine be attributed to global change forcing? Given novel drivers of community assembly and ongoing global change, what are sensible restoration goals and strategies for large post-industrial areas? Location A decommissioned brown coal mine near Søby, central Denmark (56°...

Defaunation is a global threat to biodiversity that can be counteracted through trophic rewilding, a restoration strategy that promotes self-regulating ecosystems through active reintroductions or passive management. In order to estimate success in restoration initiatives, progress of the rewilding projects is measured and monitored. However, a spa...

Aim The plant species sharing ancestors now disjunctly distributed in eastern Asia (EAS) and eastern North America (ENA) have long been a biogeographic puzzle. Species within the EAS–ENA disjunct genera are presumed to exhibit niche conservatism, the tendency of closely related species to be more ecologically similar, reflecting lineages’ common ev...

Aim: Addressing global environmental challenges requires access to biodiversity data across wide spatial, temporal and biological scales. Recent decades have witnessed an exponential increase of biodiversity information aggregated by biodiversity databases (hereafter ‘databases’). However, heterogeneous coverage, protocols, and standards of databas...

Aim The number of naturalized (i.e. established) alien species has increased rapidly over recent centuries. Given the differences in environmental tolerances among species, little is known about what factors determine the extent to which the observed size of the naturalized range of a species and hence the extent to which the observed richness of n...

Understanding drivers of success for alien species can inform on potential future invasions. Recent conceptual advances highlight that species may achieve invasiveness via performance along at least three distinct dimensions: 1) local abundance, 2) geographic range size, and 3) habitat breadth in naturalized distributions. Associations among these...

Measures of β‐diversity are known to be biased by differences in γ‐diversity (i.e., γ‐dependence), making it challenging to compare β‐diversity across regions. Undersampling corrections have been designed to reduce effects of γ‐dependence on β‐diversity arising from the problem of incomplete sampling. However, no study has systematically tested the...

There is increasing focus on reforestation, but the efforts still often include limited subsets of species despite evidence that tree diversity promote biodiversity and ecological resilience. In addition to these benefits, greater inclusion of rare native species in reforestation efforts would also help conserve these species in an uncertain future...

Aim This work explores whether the commonly observed positive range size–niche breadth relationship exists for Fagus, one of the most dominant and widespread broad‐leaved deciduous tree genera in temperate forests of the Northern Hemisphere. Additionally, we ask whether the 10 extant Fagus species’ niche breadths and climatic tolerances are under p...

From global nature conservation policies to carbon off-set private initiatives, the focus on tree promotion, and tree planting in particular, as a nature-based solution to global environmental crises such as climatic change and biodiversity loss dominates the current discourse. Yet, this fixation on trees does not reflect a scientific consensus on...

Archaeological and paleoecological evidence shows that by 10,000 BCE, all human societies employed varying degrees of ecologically transformative land use practices, including burning, hunting, species propagation, domestication, cultivation, and others that have left long-term legacies across the terrestrial biosphere. Yet, a lingering paradigm am...

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tend...

Questions The human‐related spread of alien plants has serious environmental and socioeconomic impacts. Therefore, it is important to know which habitats are most threatened by invasion and why. We studied a wide range of European grasslands to assess: (a) which alien species are the most successful invaders in grasslands; (b) how invasion levels d...

Trophic rewilding provides a nature-based solution for biological conservation; however, empirical studies demonstrating rewilding effects are limited. Megaherbivores moderate the type and quality of habitat available to other fauna. However, these effects may take time to develop. Further, fauna responses to megaherbivore rewilding will depend on...

The human introduction and spread of species in urban greenspace may lead to an increase in the similarity of plant species composition between distant areas. Univervsity campuses are an important element of greenspace in many cities, but we know little about the extent to which such biotic homogenization of plant species can be detected across dif...

Aim: This work explores whether the commonly observed positive range size–niche breadth relationship exists for Fagus, one of the most dominant and widespread broad-leaved deciduous tree genera in temperate forests of the Northern Hemisphere. Additionally, we ask whether the 10 extant Fagus species’ niche breadths and climatic tolerances are under...

Questions European woodlands harbor at least 386 alien plant species but the factors driving local invasions remain unknown. By using a large vegetation‐plot database, we asked how local richness and abundance of alien species vary by regions, elevation, climate, soil properties, human disturbance, and habitat types. Location Western, Central and S...

The potential for megafauna restoration is unevenly distributed across the world, along with the socio-political capacity of countries to support these restoration initiatives. We show that choosing a recent baseline to identify species' indigenous range puts a higher burden for megafauna restoration on countries in the Global South, which also hav...

Aim Palms are an ecologically and societally important plant group, with high diversity in the Neotropics. Here, we estimated the impacts of future climate change on phylogenetic diversity (PD) of Neotropical palms under varying climatic and dispersal scenarios, assessed the effectiveness of the established network of protected areas (PAs) for cons...