Enno Uhl

• Technical University of Munich

The comparative roles of species and structural diversity in mitigating the impacts of salinity were evaluated. Greater diversity contributes to mitigating salinity impacts by interacting with nutrients and leaf functional trait. Nutrients and leaf functional trait (leaf area) significantly influenced the effects of salinity on mangrove growth. Fut...

Trees are integral to ecosystems and hold considerable economic importance. Their exceptional longevity and modular structure also make them valuable models for studying the long-term accumulation of somatic mutations and epimutations in plants. Empirical evidence indicates that the annual rate of these stochastic events correlates negatively with...

Crown trait-based ecology has significantly advanced, yet a substantial knowledge gap remains regarding its predictive power on internal tree morphology and future growth potential across different species. Our research addressed this gap by examining how crown traits of various species manifest in temporal tree growth dynamics by answering three r...

Key message We found a significant increase in the latewood density of European beech, and a decrease in the latewood and mean wood density of silver fir and Norway spruce in European mountain forests over the period 1901–2016. In the past century, drought did not directly influence the wood density trend of the three studied species. However, for...

Societal Impact Statement Forests worldwide face significant challenges due to climate change, impacting their health and productivity. In this study, we examined how European beech and Scots pine influence each other's phenology and growth in mixed forests. Our findings indicate that mixing these complementary tree species can increase resource ef...

Carbon stocks and flows in forest ecosystems play an important role in the context of climate change mitigation. Different aspects of the forest carbon balance, however, are often treated independently, leading to a fragmented, disciplinary knowledge. With the R-package care4cmodel we want to support a consolidated view of forest growth and forest...

As an essential nutrient, Nitrogen (N) availability is fundamental in evaluating forest productivity, and as such, understanding the effects of changing atmospheric N inputs in forest ecosystems is of high significance. While most field experiments have been employing ground fertilization as a method to simulate N deposition, two experimental fores...

Trees are critical components of ecosystems and of major economic importance. Due to their extraordinary longevity and well-defined modular architecture they have also emerged as model systems to study the long-term accumulation of somatic mutations in plants. Coupled with retrospective life-history and environmental data, trees can offer unique in...

3D crown shape and tree ring development are autobiographies of the growth conditions. With advancements in terrestrial laser scanning, modeling growth from 3D crown structure offers insights into trees' structural and functional responses in a non-destructive and repetitive way. However, how the trees in different growing conditions respond in 3D...

To enhance our understanding of forest carbon sequestration, climate change mitigation and drought impact on forest ecosystems, the availability of high-resolution annual forest growth maps based on tree-ring width (TRW) would provide a significant advancement to the field. Site-specific characteristics, which can be approximated by high-resolution...

Forests provide a range of vital services to society and are critical habitats for biodiversity, holding inherent multifunctionality. While traditionally viewed as a byproduct of production-focused forestry, today's forest ecosystem services and biodiversity (FESB) play an essential role in several sectoral policies’ needs. Achieving policy objecti...

Introduction Forests are threatened by increasingly severe and more frequent drought events worldwide. Mono-specific forests, developed as a consequence of widespread management practices established early last century, seem particularly susceptible to global warming and drought compared with mixed-species forests. Although, in several contexts, mi...

Key Message Beech growth acclimated better during severe drought and recovered faster than spruce after drought ended. This was associated with a shift in performance along relative tree size towards small trees. Abstract The effects of several consecutive drought years and the recovery reaction of mature trees in particular after a long-term drou...

During the summer of 2022, an acute drought once more afflicted central and southern Europe. This marked the third episode (after 2015 and 2018) of severe aridity in large parts of Germany within the last decade, leading to increased soil water depletion. Consequently, from July 2022 onward, European beech trees (Fagus sylvatica L.) exhibited early...

Key message Considering their drought tolerance and growth characteristics, rare native tree species are well-suited admixed species for the development of climate-stable forests in Central Europe. Abstract In our study, we assessed the growth and drought reaction of the four rare native tree species European hornbeam (Carpinus betulus L.), Europe...

Aim of study: Detecting possible small-scale soil effects on height growth of single trees in monospecific stands of three important tree species (Abies alba, Fagus sylvatica, and Picea abies). Area of study: 37 mature stands along an ecological gradient in Southern Germany from the cold and wet “optimal niche zone” to warmer and drier niche zones...

European countries have national sectoral polices to regulate and promote the provision of a wide range of forest ecosystems services (FES). However, potential incoherencies among these policies can negatively affect the efficient provision of FES. In this work, we evaluated the coherence among three national policies from Germany and their ability...

Process-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environme...

Against the backdrop of global change, the intensity, duration, and frequency of droughts are projected to increase and threaten forest ecosystems worldwide. Tree responses to drought are complex and likely to vary among species, drought characteristics, and site conditions. Here, we examined the drought response patterns of three major temperate t...

Traditionally, due to its light ecology, oak is regenerated on clear cuts or areas where the crown coverage is heavily reduced. Thus, the regeneration phase is relatively short. Recently, selective long-term regeneration phases avoiding large gaps in the canopy but fostering mixed-species stands have been advocated as being more in keeping with clo...

Forest fungi provide recreational and economic services, as well as ecosystem biodiversity. Wild mushroom yields are difficult to estimate; climatic conditions are known to trigger temporally localised yields, and forest structure also affects productivity. In this work, we analyse the capacity of remotely sensed variables to estimate wild mushroom...

Rare domestic tree species are increasingly being viewed as promising alternatives and additions to current main tree species in forests facing climate change. For a feasible management of these rare species, it is, however, necessary to know their growth patterns and space requirements. This information has been lacking in management and science u...

Urban tree managers are challenged with sustainable ecosystem service provision in particular when urban tree populations become over mature. Therefore, managers have to quantify both future services and population stability. We exemplify an approach for estimating the tradeoff between cooling, CO2-fixation and crown volume development, and the tim...

El inventario forestal por métodos de masa con tecnología LiDAR está implantado operativamente en España. Una de sus principales limitaciones es el coste de adquisición de datos, que supone largos periodos entre campañas de captura, lo que, unido a la obsolescencia del mismo ante perturbaciones naturales o artificiales, especialmente en ecosistemas...

Heterogeneity of structure can increase mechanical stability, stress resistance and resilience, biodiversity and many other functions and services of forest stands. That is why many silvicultural measures aim at enhancing structural diversity. However, the effectiveness and potential of structuring may depend on the site conditions. Here, we reveal...

Wood production is one of the most important ecosystem service that forests provide to society. However, under changing climatic conditions, this appears to be subject to increasing uncertainties. In the present study we analyzed how long-term productivity of oak (Quercus petraea [Matt.] Liebl. and Quercus robur L.) stands has developed, how oak be...

The need to understand the carbon sequestration ability of trees under current and future climatic scenarios is fundamental to predict the role of forest in counterbalancing the global warming. In this study, we investigated the carbon sequestration ability of Pinus sylvestris L. in a setting of pure and mixed forests with Quercus petraea (Matt.) L...

Due to high productivity and past management approaches, the forests of Central Europe are heavily dominated by conifers, even on sites where they do not occur naturally at all. One prominent example is Norway spruce (Picea abies H. Karst.), a species considered particularly vulnerable to severe droughts, especially outside of its ecological niche...

Understanding tree and stand growth dynamics in the frame of climate change calls for large-scale analyses. For analysing growth patterns in mountain forests across Europe, the CLIMO consortium compiled a network of observational plots across European mountain regions. Here, we describe the design and efficacy of this network of plots in monospecif...

This chapter addresses the concepts and methods to assess quantitative indicators of Climate-Smart Forestry (CSF) at stand and management unit levels. First, the basic concepts for developing a framework for assessing CSF were reviewed. The suitable properties of indicators and methods for normalization, weighting, and aggregation were summarized....

In this chapter, we review the current long-term growth trends and short-term growth reaction to single or repeated stress events on tree and stand level in Europe. Based on growth trend analyses, the chapter reveals the strong human footprint on forest ecosystems. First, we use long-term experiments and increment cores to show change in growth tre...

Die Trauben- und die Stieleiche sind zwei heimische Baumarten, die aufgrund ihrer breiten ökologischen Amplituden und vergleichsweise hohen Trockenheitstoleranz im Klimawandel eine wichtige Rolle im Waldumbau spielen können. Wie sich ihr Höhenwachstum entlang eines klimatischen Gradienten und bei unterschiedlicher Bestandesstruktur verhält, wurde i...

Resilient ecosystems provide natural insurance value, or resilience value, to the landowner and to society at large. In response to global calls for integrating biodiversity in sector policy and planning, we analysed the specified resilience value by simulating three storm regimes and five management scenarios: Business As Usual/BAU (spruce-dominan...

Compared with far-developed measures and methods for mono-specific forest stands, the silvicultural prescriptions for mixed-species stands are at their early beginning. However, they are essential for the well-conceived establishment, design, and control of mixed-species stands, currently promoted in many countries worldwide. Here, we review the st...

Numerous studies reveal an accelerated growth in European forests and globally. Trees and stand are growing faster than a hundred years ago. Seemingly, global change leads to improved resource supply. Based on long term growth and yield trials from Lower Saxony and Bavaria similar trend changes can be observed for monospecific and mixed oak stands....

Pedunculate and sessile oak are widely distributed across Europe due to their large ecological amplitude. Thus, there is a rich silvicultural experience with oak in different European countries. With the help of a survey in 18 countries, an overview of the respective silvicultural objectives and approaches could be established. The dominant product...

In the evaluation, the productivity of monospecific and mixed oak stands and individual trees growing on long-term experimental plots was analyzed on the basis of stand structural characteristics. According to the results, stand productivity is up to 22% higher in mixed stands than in monospecific stands. The increase is mainly determined by beech...

In 28 of 30 Bavarian strict forest reserves (SFR) with oak investigated, a build-up of stocks has been discernible since the beginning of the surveys since over 40 years. The basal area proportion of oak (Quercus sp.) decreased by an average of 0.02% per year in oak forest communities and by 0.12% per year in beech forest communities. The mortality...

Natural forest management methods are increasingly becoming the focus of silvicultural regeneration procedures. Classical oak regeneration techniques are mostly carried out on large areas. Long-term and small-scaled regeneration are hardly applied. Also due to competition from mixed tree species. On long-term experiments in the Steigerwald, Spessar...

Forests in Europe are currently not endangered by soil erosion. However, this can change with climate change or with intensified forest management practices. Using a newly established network of plots in beech forests across Europe, the aims of this study were to (i) distinguish soil properties and erodibility indices in relation to bedrock, (ii) d...

Carbon smart forestry under climate change In the fight against climate change, forestry needs to contribute to carbon sink and a low carbon-emitting society. Forests sequester carbon and simultaneously release carbon during forest operations. Our ambition is to achieve an integrated picture of carbon sink and source; to adapt forest management for...

Currently, silvicultural prescriptions such as thinning monospecific stands from above and transitioning from monospecific to mixed-species stands are scrutinised regarding their ability to reduce stress and damage. That the quantity and quality of the trees harvested by intermediate and final cuts will vary depending on the chosen prescription is...

Research Highlights: We make use of long term observation data from a selection forest in Bavaria. Despite the changing environmental conditions, stand level productivity remains constant over time. Maintaining species and structural diversity by forest management can contribute to resilient forest ecosystems. Background and Objectives: Forests in...

Developing “climate smart forestry” (CSF) indicators in mountain forest regions requires collection and evaluation of local data and their attributes. Genetic resources are listed among the core indicators for forest biological diversity. This study is a report on the evaluation of the standing genetic diversity within and across 12 pure beech stan...

Fagus sylvatica L. is widely distributed across Europe thanks to its high adaptability in a wide variety of soils and climate. Microbial communities are essential for maintaining forest soil quality and are responsible for forest ecosystem functioning; the ability of soil microorganisms to respond to abiotic stressors (e.g., organic carbon losses,...

Recent studies show that several tree species are spreading to higher latitudes and elevations due to climate change. European beech, presently dominating from the colline to the subalpine vegetation belt, is already present in upper montane subalpine forests and has a high potential to further advance to higher elevations in European mountain fore...

Despite growing evidence that diverse forests play an important role in ecosystem functioning, ensuring the provision of different ecosystem services, whether such diversity improves their response to drought events remains unclear. In this study, we use a large tree-ring database from thirty case studies across nine European countries and eleven s...

Sessile oak (Quercus petraea (Matt.) Liebl.) and pedunculate oak (Quercus robur L.) play an important role in increasing the resistance of central European forests to severe droughts. But outside their real niche the competitiveness of both oak species can be low in mixed-species stands. This paper examines the height growth of oaks depending on en...

Currently the paradigm of sustainable forest management is extended to a broad range of ecological, economic, and social forest functions and services. In particular, biodiversity becomes a more and more important issue in the forest planning processes. However, its quantification, monitoring and assessment still remain complex and difficult althou...

Spruce-fir-beech mixed forests cover a large area in European mountain regions, with high ecological and socioeconomic importance. As elevation-zone systems they are highly affected by climate change, which is modifying species growth patterns and productivity shifts among species. The extent to which associated tree species can access resources an...

This study analyses a tree’s short-term allocation pattern under varying weather conditions. Based on a sample of 311 stem discs of the stem boles from 92 European beech (Fagus sylvatica L.) trees, the annual stem taper was calculated retrospectively over multiple decades and linked to the annual weather conditions. The bole shape results from long...

At two forest sites in Germany (Pfaffenwinkel, Pustert) stocked with mature Scots pine (Pinus sylvestris L.), we investigated changes of topsoil chemistry during the recent forty years by soil inventories conducted on replicated control plots of fertilization experiments, allowing a statistical analysis. Additionally, we monitored the nutritional s...

In Europe, mixed mountain forests, primarily comprised of Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.), and European beech (Fagus sylvatica L.), cover about 10 × 10⁶ ha at elevations between ∼600 and 1600 m a.s.l. These forests provide invaluable ecosystem services. However, the growth of these forests and the competition...

Die Sommermonate 2015 und 2018 gaben einen eindrucksvollen Vorgeschmack auf die uns erwartenden klimatischen Veränderungen. Zahlreiche Baumarten litten stark unter der Trockenheit in Verbindung mit warmen bis heißen Temperaturen. Es ist davon auszugehen, dass viele Baumarten mit dem zukünftigen Klima nicht mehr zurecht kommen werden. So wird der Ru...

Urban tree growth is often affected by reduced water availability, higher temperatures, small and compacted planting pits, as well as high nutrient and pollution inputs. Despite these hindering growth conditions, recent studies found a surprisingly better growth of urban trees compared to trees at rural sites, and an enhanced growth of trees in rec...

Mixed mountain forests of European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst), and silver fir (Abies alba Mill.) cover a total area of more than 10 million hectares in Europe. Due to altitudinal zoning, these forests are particularly vulnerable to climate change. However, as little is known about the long-term development of...

The project MULTIFOREST aims to lay a solid basis for solving the socio-ecological land-use conflicts in European boreal and temperate forests caused by incoherent EU and national policies. Novel insights are provided to forest policy, forest management and land-use planning by qualitative and quantitative impact analyses of policies and their rela...

Forest stand growth dynamics in Central Europe have accelerated since 1870 due to a rise in temperature, extended growing seasons, and other components of climate change. Based on wood samples from the oldest existing experimental plots in Central Europe, we show that the dominant tree species Norway spruce (Picea abies (L.) H.Karst.), Scots pine (...

Abstract Background Recent projections expect that Vietnam will be affected most severely by climate change with higher temperatures, more precipitation and rising sea levels. Especially increased temperatures will worsen the situations in cities, amplifying the urban heat island effect. Green infrastructures, i.e. urban trees are a common tool to...

Urban trees and the services they provide (e.g., evapotranspirational cooling, shading, recreation, carbon storage, air pollution filtering) can have major effects on the microclimate of a city, although the growth conditions are often inadequate to ensure tree vitality and growth, negatively affecting their beneficial effects. In a worldwide dendr...

Due to predicted climate change, it is important to know to what extent trees and forests will be impacted by chronic and episodic drought stress. As oaks play an important role in European forestry, this study focuses on the growth response of sessile oak (Quercus petraea (Matt.) Liebl.) and pedunculate oak (Quercus robur (L.)) under contrasting c...

Zusammenfassung Bergmischwälder aus Fichte (Picea abies (L.) Karst), Weißtanne (Abies alba Mill.) und Europäischer Rot-buche (Fagus sylvatica) bedecken in Europa eine Gesamtfläche von mehreren Millionen Hektar. Sie verbinden die Buchenwaldgesellschaften im Tiefland mit den fichtendominierten, alpinen Waldtypen. Aufgrund ihrer Höhenzonierung sind di...

Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees (Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of incr...

Key message Relative biomass of tree compartments is dependent on plant size and stand density, with stand density being an important predictor, especially for belowground biomass and at high stand densities. Abstract Estimation of biomass production is an important issue against the background of climate change and carbon storage. Even though man...

Eine Herausforderung für die Forstwissenschaft ist es, den Waldbesitzern Handlungsempfehlungen für die Waldbewirtschaftung im Klimawandel zu geben. Doch aus der Vielzahl existierender Anbauten, Anbauempfehlungen und möglicher Baumarten scheint es nicht immer einfach, eine geeignete Auswahl zu treffen. Wir stellen vier Forschungsansätze vor, die zu...

Despite the importance of urban trees, their growth reaction to climate change and to the urban heat island effect has not yet been investigated with an international scope. While we are well informed about forest growth under recent conditions, it is unclear if this knowledge can be simply transferred to urban environments. Based on tree ring anal...

The growing conditions of urban trees differ substantially from forest sites and are mainly characterized by small planting pits with less water, nutrient and aeration availability, high temperatures and radiation inputs as well as pollution and soil compaction. Especially, global warming can amplify the negative effects of urban microclimates on t...