Richard L. Peters

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Verified

Richard verified their affiliation via an institutional email.

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• PhD
• Professor (Associate) at Technical University of Munich

Introduction Quantitative wood anatomy is critical for establishing climate reconstruction proxies, understanding tree hydraulics, and quantifying carbon allocation. Its accuracy depends upon the image acquisition methods, which allows for the identification of the number and dimensions of vessels, fibres, and tracheids within a tree ring. Angiospe...

Stomata control plant water loss and photosynthetic carbon gain. Developing more generalized and accurate stomatal models is essential for earth system models and predicting responses under novel environmental conditions associated with global change. Plant optimality theories offer one promising approach, but most such theories assume that stomata...

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigati...

Introduction The Congo Basin forests, a crucial global carbon sink, are expected to face increased challenges of climate change by 2027, with an expected temperature rise of 1.5°C above pre-industrial levels, accompanied by increased humidity conditions. However, studies that try to understand their functioning and untangle the species-specific res...

As major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carb...

Climate change is predicted to increase atmospheric vapor pressure deficit, exacerbating soil drought, and thus enhancing tree evaporative demand and mortality. Yet, few studies have addressed the longer-term drought acclimation strategy of trees, particularly the importance of morphological vs. hydraulic plasticity. Using a long-term (20 years) ir...

Tree-specific canopy conductance (Gc) and its adjustment play a critical role in mitigating excess water loss in changing environmental conditions. However, the change of Gc sensitivity to environmental conditions due to drought remains unclear for European tree species. Here we quantified the environmental operational space of Gc, i.e., the water...

Wood growth is key to understanding the feedback of forest ecosystems to the ongoing climate warming. An increase in spatial synchrony (i.e., coincident changes in distant populations) of spring phenology is one of the most prominent climate responses of forest trees. However, whether temperature variability contributes to an increase in the spatia...

The fraction of photosynthetically assimilated carbon that trees allocate to long-lasting woody biomass pools (biomass production efficiency – BPE), is a key metric of the forest carbon balance. Its apparent simplicity belies the complex interplay between underlying processes of photosynthesis, respiration, litter and fruit production, and tree gro...

Tree crown conductance (Gc) and its intraspecific variability play a critical role in mitigating excess water loss in persistently changing environmental conditions. Although Gc regulation is often assessed with vapor pressure deficit (D) or soil water potential (soil), a more direct internal water status measurement of continuous leaf water poten...

Tropical forests are experiencing increases in vapour pressure deficit (D), with possible negative impacts on tree growth. Tree-growth reduction due to rising D is commonly attributed to carbon limitation, thus overlooking the potentially important mechanism of D-induced impairment of wood formation due to an increase in turgor limitation. Here we...

Trees remain sufficiently hydrated during drought by closing stomata and reducing canopy conductance (Gc) in response to variations in atmospheric water demand and soil water availability. Thresholds that control the reduction of Gc are proposed to optimize hydraulic safety against carbon assimilation efficiency. However, the link between Gc and th...

The analysis of a Europe-wide network of tree-ring stable isotopes has shown that the climatic signal of δ2H in tree-ring cellulose (C6H10O5), is far weaker compared to those recorded in carbon (δ13C) and oxygen (δ18O)isotopes. Furthermore, the δ2H and δ18O relationships were shown to be site dependent and significantly deviated from the Global Met...

Partitioned estimates of the boreal forest carbon (C) sink components are crucial for understanding processes and developing science-driven adaptation and mitigation strategies under climate change. Here, we provide a concise tree-centered overview of the boreal forest C balance and offer a circumpolar perspective on the contribution of trees to bo...

Recent experiments have underlined the potential of δ2H in tree-ring cellulose as a physiological indicator of shifts in autotrophic versus heterotrophic processes (i.e., the use of fresh versus stored non-structural carbohydrates). However, the impact of these processes has not yet been quantified under natural conditions. Defoliator outbreaks dis...

Forests account for nearly 90 % of the world's terrestrial biomass in the form of carbon and they support 80 % of the global biodiversity. To understand the underlying forest dynamics, we need a long-term but also relatively high-frequency, networked monitoring system, as traditionally used in meteorology or hydrology. While there are numerous exis...

Drought legacies in radial tree growth are an important feature of variability in biomass accumulation and are widely used to characterize forest resilience to climate change. Defined as a deviation from normal growth, the statistical significance of legacy effects depends on the definition of “normal”—expected growth under average conditions—which...

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio-temporal scales implies a potential existence of a thermal threshold in the responses of forests to glo...

Sapwood characteristics, such as sapwood area as well as thermal and hydraulic conductivity, are linked to species-specific hydraulic function and resource allocation to water transport tissues (xylem). These characteristics are often unknown and thus a major source of uncertainty in sap flow data processing and transpiration estimates because bulk...

Ecological research, just as all Earth System Sciences, is becoming increasingly data-rich. Tools for processing of “big data” are continuously developed to meet corresponding technical and logistical challenges. However, even at smaller scales, data sets may be challenging when best practices in data exploration, quality control and reproducibilit...

Tree-ring annual growth and wood anatomical traits were used for the retrospective analysis of the impact of hydro-climatic conditions on the orchard irrigation management. Data were collected in the oldest (20 years), in full-production, orchards of Emilia-Romagna (Italy), one of the most important Italian Region for fruit production. Despite the...

Human-driven peatland drainage has occurred in Europe for centuries, causing habitat degradation and leading to the emission of greenhouse gases. As such, in the last decades, there has been an increase in policies aiming at restoring these habitats through rewetting. Alder (Alnus glutinosa L.) is a widespread species in temperate forest peatlands...

Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-tempor...

Radial stem growth dynamics at seasonal resolution are essential to understand how forests respond to climate change. We studied daily radial growth of 160 individuals of seven temperate tree species at 47 sites across Switzerland over 8 years. Growth of all species peaked in the early part of the growth season and commenced shortly before the summ...

The recent developments in artificial intelligence have the potential to facilitate new research methods in ecology. Especially Deep Convolutional Neural Networks (DCNNs) have been shown to outperform other approaches in automatic image analyses. Here we apply a DCNN to facilitate quantitative wood anatomical (QWA) analyses, where the main challeng...

The TreeNet research and monitoring network has been continuously collecting data from point dendrometers and air and soil microclimate using an automated system since 2011. The goal of TreeNet is to generate high temporal resolution datasets of tree growth and tree water dynamics for research and to provide near real-time indicators of forest grow...

The timing of diel stem growth of mature forest trees is still largely unknown, as empirical data with high temporal resolution have not been available so far. Consequently, the effects of day–night conditions on tree growth remained uncertain. Here we present the first comprehensive field study of hourly‐resolved radial stem growth of seven temper...

Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observatio...

Radial stem size changes, measured with automated dendrometers at intra-daily resolution, offer great potential to link environmental conditions with tree physiology at the seasonal scale. Such measurements need to be time-aligned, cleaned of outliers and shifts, gap-filled and analysed for reversible (water-related) and irreversible (growth-relate...

In their Letter, Elmendorf and Ettinger (1) question the dominant role of photoperiod in driving secondary growth resumption (hereafter referred to as xylem formation onset) of the Northern Hemisphere conifers, recently reported by Huang et al. (2). Their opinions are grounded on the following three aspects, including 1) the seasonality of the phot...

Vegetation models are converging on an intermediate complexity with the tree level as the target for simulation. Field and laboratory observations of forest ecosystem processes are indispensable to parameterize, evaluate, or be assimilated into tree-centered vegetation models. Observations of C allocation in trees are not being developed at the sam...

A key ecophysiological measurement is the flow of water (or sap) along the tree's water‐transport system, which is an essential process for maintaining the hydraulic connection within the soil–plant–atmosphere continuum. The thermal dissipation method (TDM) is widespread in the scientific community for measuring sap flow and has provided novel insi...

A valid representation of intra‐annual wood formation processes in global vegetation models is vital for assessing climate change impacts on the forest carbon stock. Yet, wood formation is generally modelled with photosynthesis, despite mounting evidence that cambial activity is rather directly constrained by limiting environmental factors. Here, w...

Significance Forest trees can live for hundreds to thousands of years, and they play a critical role in mitigating global warming by fixing approximately 15% of anthropogenic CO 2 emissions annually by wood formation. However, the environmental factors triggering wood formation onset in springtime and the cellular mechanisms underlying this onset r...

Insect defoliation impacts forest productivity worldwide, highlighting the relevance of plant-insect interactions. The larch budmoth (Zeiraphera griseana Hübner) is one of the most extensively studied defoliators, where numerous tree-ring based analyses on its host (Larix decidua Mill.) have aided in identifying outbreak dynamics over the past mill...

Defoliator insects are a major disturbance agent in many forests worldwide. During outbreaks, they can strongly reduce photosynthetic carbon uptake and impact tree growth. In the Alps, larch budmoth (Zeiraphera diniana) outbreaks affect European larch (Larix decidua) radial growth over several years. However, immediate and legacy effects on xylem f...

Tree growth is an indicator of tree vitality and its temporal variability is linked to species resilience to environmental changes. Second‐order statistics that quantify the cross‐scale temporal variability of ecophysiological time series (statistical memory) could provide novel insights into species resilience. Species with high statistical memory...

Efforts to develop mechanistic tree growth models are hindered by the uncertainty of whether and when tree growth responses to environmental factors are driven by carbon assimilation or by biophysical limitations of wood formation. In this study, we used multiannual weekly wood‐formation monitoring of two conifer species (Larix decidua and Picea ab...

During the growing season, trees allocate photoassimilates to increase their aboveground woody biomass in the stem (ABIstem). This "carbon allocation" to structural growth is a dynamic process influenced by internal and external (e.g., climatic) drivers. While radial variability in wood formation and its resulting structure have been intensely stud...

We used four years of sap flow measurements to elucidate intra‐ and inter‐specific variability of gs in Larix decidua Mill. and Picea abies (L.) Karst along an elevational gradient and contrasting soil moisture conditions. Site‐ and species‐specific gs response to main environmental drivers were examined, including vapour pressure deficit, air temp...

Conifer trees possess a typical anatomical tree‐ring structure characterized by a transition from large and thin‐walled earlywood tracheids to narrow and thick‐walled latewood tracheids. However, little is known on how this characteristic structure is maintained across contrasting environmental conditions, due to its crucial role to ensure sap asce...

Dated tree rings are used to understand tree-growth responses to climatic variability and reconstruct past climate conditions. In parallel, mechanistic models make use of experimentally derived plant-atmosphere interactions to simulate past and future environmental impact on forest productivity. Yet, substantial model inconsistencies and mismatches...

Trees play a key role in the global hydrological cycle and measurements performed with the thermal dissipation method ( TDM ) have been crucial in providing whole‐tree water‐use estimates. Yet, different data processing to calculate whole‐tree water use encapsulates uncertainties that have not been systematically assessed. We quantified uncertainti...

Conifers show a biogeographical distribution across a wide range of contrasting environmental conditions, stretching from the Arctic Circle to the equator and Southern Hemisphere. In mountainous ecosystems, conifers can dominate at high elevations with low temperatures severely limiting tree growth and survival. Conifers growing at sites with tempe...

Trees scale leaf ( A L ) and xylem ( A X ) areas to couple leaf transpiration and carbon gain with xylem water transport. Some species are known to acclimate in A L : A X balance in response to climate conditions, but whether trees of different species acclimate in A L : A X in similar ways over their entire (continental) distributions is unknown....

Mechanistic understanding of tree-ring formation and its modelling requires a cellular-based and spatially organized characterization of a tree ring, moving from whole rings, to intra-annual growth zones and individual cells. A tracheidogram is a radial profile of conifer anatomical features, such as lumen area and cell wall thickness, of sequentia...

Forest growth and biomass response to environmental change depends upon climatic, but also upon interactions with biotic drivers, such as insect outbreak activity. In this study we use tree-rings along a temperature gradient to assess the relative importance of climate versus altered larch budmoth (Zeiraphera diniana) outbreak cycles for forest bio...

Inter-annual tree-ring measurements are used to understand tree-growth responses to climatic variability and reconstruct past climate conditions. In parallel, mechanistic models use experimentally defined plant-atmosphere interactions to explain past growth responses and predict future environmental impact on forest productivity. Yet, substantial i...

The Carpathian mountain region is one of the most significant natural refuges on the European continent. It is home to Europe’s most extensive tracts of montane forest, the largest remaining virgin forest and natural mountain beech-fir forest ecosystems. Adding to the biodiversity are semi-natural habitats such as hay meadows, which are the result...

Phloem osmolality and its components are involved in basic cell metabolism, cell growth, and in various physiological processes including the ability of living cells to withstand drought and frost. Osmolality and sugar composition responses to environmental stresses have been extensively studied for leaves, but less for the secondary phloem of plan...

Tree-ring analysis is often used to assess long-term trends in tree growth. A variety of growth-trend detection methods (GDMs) exist to disentangle age/size trends in growth from long-term growth changes. However, these detrending methods strongly differ in approach, with possible implications for their output. Here we critically evaluate the consi...