Flurin Babst

Interests

Teaching

My teaching interests broadly cover the interactions and feedbacks between terrestrial vegetation and its various environmental drivers (e.g., climate or disturbances). Beyond classroom teaching, I welcome students who would like to gain hands-on research experience in my lab. We adhere to the highest standards of interpersonal conduct and reject any form of discrimination or harassment.

Research

I study the responses of tree and shrub communities to changes in their environment. A focus is thereby placed on ecological scaling using a combination of in-situ observations (vegetation census, tree rings, soil samples, etc.) with ground, airborne, and spaceborne remote sensing. I am interested in process understanding, but also in quantitative assessments of vegetation productivity. The latter helps us inform nature-based climate solutions, aiming to balance carbon gains/losses against changes in water and energy budgets.

Courses

Scholarly Contributions

Journals/Publications

• Kannenberg, S. A., Babst, F., Barnes, M. L., Cabon, A., Dannenberg, M. P., Johnston, M. R., & Anderegg, W. R. (2025). Stand density and local climate drive allocation of GPP to aboveground woody biomass. The New phytologist.
  More info

  The partitioning of photosynthate among various forest carbon pools is a key process regulating long-term carbon sequestration, with allocation to aboveground woody biomass carbon (AGBC) in particular playing an outsized role in the global carbon cycle due to its slow residence time. However, directly estimating the fraction of gross primary productivity (GPP) that goes to AGBC has historically been difficult and time-consuming, leaving us with persistent uncertainties. We used an extensive dataset of tree-ring chronologies co-located at flux towers to assess the coupling between AGBC and GPP, calculate the fraction of fixed carbon that is allocated to AGBC, and understand the drivers of variability in this fraction. We found that annual AGBC and GPP were rarely correlated, and that annual AGBC represented only a small fraction (c. 9%) of fixed carbon. This fraction varied considerably across sites and was driven by differences in stand density and site climate. Annual AGBC was suppressed by c. 30% during drought and remained below average for years afterward. These results imply that assumptions of relatively stationary allocation of GPP to woody biomass and other plant tissues could lead to systematic biases in modeled carbon accumulation in different plant pools and thus in carbon residence time.
• Sigdel, S. R., Zheng, X., Babst, F., Camarero, J. J., Gao, S., Li, X., Lu, X., Pandey, J., Dawadi, B., Sun, J., Zhu, H., Wang, T., Liang, E., & Peñuelas, J. (2024). Accelerated succession in Himalayan alpine treelines under climatic warming. Nature plants, 10(12), 1909-1918.
  More info

  Understanding how climate change influences succession is fundamental for predicting future forest composition. Warming is expected to accelerate species succession at their cold thermal ranges, such as alpine treelines. Here we examined how interactions and successional strategies of the early-successional birch (Betula utilis) and the late-successional fir (Abies spectabilis) affected treeline dynamics by combining plot data with an individual-based treeline model at treelines in the central Himalayas. Fir showed increasing recruitment and a higher upslope shift rate (0.11 ± 0.02 m yr) compared with birch (0.06 ± 0.03 m yr) over the past 200 years. Spatial analyses indicate strong interspecies competition when trees were young. Model outputs from various climatic scenarios indicate that fir will probably accelerate its upslope movement with warming, while birch recruitment will decline drastically, forming stable or even retreating treelines. Our findings point to accelerating successional dynamics with late-successional species rapidly outcompeting pioneer species, offering insight into future forest succession and its influences on ecosystem services.
• Wei, J., von Arx, G., Fan, Z., Ibrom, A., Mund, M., Knohl, A., Peters, R. L., & Babst, F. (2024). Drought alters aboveground biomass production efficiency: Insights from two European beech forests. The Science of the total environment, 919, 170726.
  More info

  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 growth that respond differently to climate variability. Whereas the magnitude of BPE has been routinely quantified in ecological studies, its temporal dynamics and responses to extreme events such as drought remain less well understood. Here, we combine long-term records of aboveground carbon increment (ACI) obtained from tree rings with stand-level gross primary productivity (GPP) from eddy covariance (EC) records to empirically quantify aboveground BPE (= ACI/GPP) and its interannual variability in two European beech forests (Hainich, DE-Hai, Germany; Sorø, DK-Sor, Denmark). We found significant negative correlations between BPE and a daily-resolved drought index at both sites, indicating that woody growth is de-prioritized under water limitation. During identified extreme years, early-season drought reduced same-year BPE by 29 % (Hainich, 2011), 31 % (Sorø, 2006), and 14 % (Sorø, 2013). By contrast, the 2003 late-summer drought resulted in a 17 % reduction of post-drought year BPE at Hainich. Across the entire EC period, the daily-to-seasonal drought response of BPE resembled that of ACI, rather than that of GPP. This indicates that BPE follows sink dynamics more closely than source dynamics, which appear to be decoupled given the distinctive climate response patterns of GPP and ACI. Based on our observations, we caution against estimating the magnitude and variability of the carbon sink in European beech (and likely other temperate forests) based on carbon fluxes alone. We also encourage comparable studies at other long-term EC measurement sites from different ecosystems to further constrain the BPE response to rare climatic events.
• Zheng, X., Babst, F., Camarero, J. J., Li, X., Lu, X., Gao, S., Sigdel, S. R., Wang, Y., Zhu, H., & Liang, E. (2024). Density-dependent species interactions modulate alpine treeline shifts. Ecology letters, 27(4), e14403.
  More info

  Species interactions such as facilitation and competition play a crucial role in driving species range shifts. However, density dependence as a key feature of these processes has received little attention in both empirical and modelling studies. Herein, we used a novel, individual-based treeline model informed by rich in situ observations to quantify the contribution of density-dependent species interactions to alpine treeline dynamics, an iconic biome boundary recognized as an indicator of global warming. We found that competition and facilitation dominate in dense versus sparse vegetation scenarios respectively. The optimal balance between these two effects was identified at an intermediate vegetation thickness where the treeline elevation was the highest. Furthermore, treeline shift rates decreased sharply with vegetation thickness and the associated transition from positive to negative species interactions. We thus postulate that vegetation density must be considered when modelling species range dynamics to avoid inadequate predictions of its responses to climate warming.
• Gao, S., Camarero, J. J., Babst, F., & Liang, E. (2023). Global tree growth resilience to cold extremes following the Tambora volcanic eruption. Nature communications, 14(1), 6616.
  More info

  Although the global climate is warming, external forcing driven by explosive volcanic eruptions may still cause abrupt cooling. The 1809 and 1815 Tambora eruptions caused lasting cold extremes worldwide, providing a unique lens that allows us to investigate the magnitude of global forest resilience to and recovery from volcanic cooling. Here, we show that growth resilience inferred from tree-ring data was severely impacted by cooling in high latitudes and elevations: the average tree growth decreased substantially (up to 31.8%), especially in larch forests, and regional-scale probabilities of severe growth reduction (below -2σ) increased up to 1390%. The influence of the eruptions extended longer (beyond the year 1824) in mid- than in high-latitudes, presumably due to the combined impacts of cold and drought stress. As Tambora-size eruptions statistically occur every 200-400 years, assessing their influences on ecosystems can help humankind mitigate adverse impacts on natural resources through improved management, especially in high latitude and elevation regions.
• Peters, R. L., Steppe, K., Pappas, C., Zweifel, R., Babst, F., Dietrich, L., von Arx, G., Poyatos, R., Fonti, M., Fonti, P., Grossiord, C., Gharun, M., Buchmann, N., Steger, D. N., & Kahmen, A. (2023). Daytime stomatal regulation in mature temperate trees prioritizes stem rehydration at night. The New phytologist, 239(2), 533-546.
  More info

  Trees remain sufficiently hydrated during drought by closing stomata and reducing canopy conductance (G ) in response to variations in atmospheric water demand and soil water availability. Thresholds that control the reduction of G are proposed to optimize hydraulic safety against carbon assimilation efficiency. However, the link between G and the ability of stem tissues to rehydrate at night remains unclear. We investigated whether species-specific G responses aim to prevent branch embolisms, or enable night-time stem rehydration, which is critical for turgor-dependent growth. For this, we used a unique combination of concurrent dendrometer, sap flow and leaf water potential measurements and collected branch-vulnerability curves of six common European tree species. Species-specific G reduction was weakly related to the water potentials at which 50% of branch xylem conductivity is lost (P ). Instead, we found a stronger relationship with stem rehydration. Species with a stronger G control were less effective at refilling stem-water storage as the soil dries, which appeared related to their xylem architecture. Our findings highlight the importance of stem rehydration for water-use regulation in mature trees, which likely relates to the maintenance of adequate stem turgor. We thus conclude that stem rehydration must complement the widely accepted safety-efficiency stomatal control paradigm.
• Zweifel, R., Pappas, C., Peters, R. L., Babst, F., Balanzategui, D., Basler, D., Bastos, A., Beloiu, M., Buchmann, N., Bose, A. K., Braun, S., Damm, A., D'Odorico, P., Eitel, J. U., Etzold, S., Fonti, P., Rouholahnejad Freund, E., Gessler, A., Haeni, M., , Hoch, G., et al. (2023). Networking the forest infrastructure towards near real-time monitoring - A white paper. The Science of the total environment, 872, 162167.
  More info

  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 existing forest monitoring sites, particularly in temperate regions, the resulting data streams are rarely connected and do not provide information promptly, which hampers real-time assessments of forest responses to extreme climate events. The technology to build a better global forest monitoring network now exists. This white paper addresses the key structural components needed to achieve a novel meta-network. We propose to complement - rather than replace or unify - the existing heterogeneous infrastructure with standardized, quality-assured linking methods and interacting data processing centers to create an integrated forest monitoring network. These automated (research topic-dependent) linking methods in atmosphere, biosphere, and pedosphere play a key role in scaling site-specific results and processing them in a timely manner. To ensure broad participation from existing monitoring sites and to establish new sites, these linking methods must be as informative, reliable, affordable, and maintainable as possible, and should be supplemented by near real-time remote sensing data. The proposed novel meta-network will enable the detection of emergent patterns that would not be visible from isolated analyses of individual sites. In addition, the near real-time availability of data will facilitate predictions of current forest conditions (nowcasts), which are urgently needed for research and decision making in the face of rapid climate change. We call for international and interdisciplinary efforts in this direction.
• Bodesheim, P., Babst, F., Frank, D. C., Hartl, C., Zang, C. S., & Jung, M. (2022). Predicting spatiotemporal variability in radial tree growth at the continental scale with machine learning. . Environmental Data Science, 1, e9.
• Cabon, A., Kannenberg, S. A., Arain, A., Babst, F., Baldocchi, D., Belmecheri, S., Delpierre, N., Guerrieri, R., Maxwell, J. T., McKenzie, S., Meinzer, F. C., Moore, D. J., Pappas, C., Rocha, A. V., Szejner, P., Ueyama, M., Ulrich, D., Vincke, C., Voelker, S. L., , Wei, J., et al. (2022). Cross-biome synthesis of source versus sink limits to tree growth. Science (New York, N.Y.), 376(6594), 758-761.
  More info

  Uncertainties surrounding tree carbon allocation to growth are a major limitation to projections of forest carbon sequestration and response to climate change. The prevalence and extent to which carbon assimilation (source) or cambial activity (sink) mediate wood production are fundamentally important and remain elusive. We quantified source-sink relations across biomes by combining eddy-covariance gross primary production with extensive on-site and regional tree ring observations. We found widespread temporal decoupling between carbon assimilation and tree growth, underpinned by contrasting climatic sensitivities of these two processes. Substantial differences in assimilation-growth decoupling between angiosperms and gymnosperms were determined, as well as stronger decoupling with canopy closure, aridity, and decreasing temperatures. Our results reveal pervasive sink control over tree growth that is likely to be increasingly prominent under global climate change.
• Cabon, A., Kannenberg, S., Arain, A., Babst, F., Baldocchi, D., & Belmecheri, S. (2022). Cross-biome synthesis of source versus sink limits to tree growth. Science, 376, 758-761.
• Dorado-Linan, I., Ayarzaguena, B., Babst, F., Xu, G., Gil, L., & Battipaglia, G. (2022). Jet stream position explains regional anomalies in European beech forest productivity and tree growth.. Nature Communications, 13. doi:10.1038/s41467-022-29615-8
• Dorado-Liñán, I., Ayarzagüena, B., Babst, F., Xu, G., Gil, L., Battipaglia, G., Buras, A., Čada, V., Camarero, J. J., Cavin, L., Claessens, H., Drobyshev, I., Garamszegi, B., Grabner, M., Hacket-Pain, A., Hartl, C., Hevia, A., Janda, P., Jump, A. S., , Kazimirovic, M., et al. (2022). Jet stream position explains regional anomalies in European beech forest productivity and tree growth. Nature communications, 13(1), 2015.
  More info

  The mechanistic pathways connecting ocean-atmosphere variability and terrestrial productivity are well-established theoretically, but remain challenging to quantify empirically. Such quantification will greatly improve the assessment and prediction of changes in terrestrial carbon sequestration in response to dynamically induced climatic extremes. The jet stream latitude (JSL) over the North Atlantic-European domain provides a synthetic and robust physical framework that integrates climate variability not accounted for by atmospheric circulation patterns alone. Surface climate impacts of north-south summer JSL displacements are not uniform across Europe, but rather create a northwestern-southeastern dipole in forest productivity and radial-growth anomalies. Summer JSL variability over the eastern North Atlantic-European domain (5-40E) exerts the strongest impact on European beech, inducing anomalies of up to 30% in modelled gross primary productivity and 50% in radial tree growth. The net effects of JSL movements on terrestrial carbon fluxes depend on forest density, carbon stocks, and productivity imbalances across biogeographic regions.
• Dyola, N., Sigdel, S. R., Liang, E., Babst, F., Camarero, J. J., & Aryal, S. (2022). Species richness is a strong driver of forest biomass along broad bioclimatic gradients in the Himalayas. . Ecosphere, 13, e4107.
• Evans, M. E., DeRose, R. J., Klesse, S., Girardin, M. P., Heilman, K. A., Alexander, M. R., Arsenault, A., Babst, F., Bouchard, M., Cahoon, S. M., Campbell, E. M., Dietze, M., Duchesne, L., Frank, D. C., Giebink, C. L., Gómez-Guerrero, A., García, G. G., Hogg, E. H., Metsaranta, J., , Ols, C., et al. (2022). Adding Tree Rings to North America's National Forest Inventories: An Essential Tool to Guide Drawdown of Atmospheric CO2. Bioscience, 72(3), 233-246.
  More info

  Tree-ring time series provide long-term, annually resolved information on the growth of trees. When sampled in a systematic context, tree-ring data can be scaled to estimate the forest carbon capture and storage of landscapes, biomes, and-ultimately-the globe. A systematic effort to sample tree rings in national forest inventories would yield unprecedented temporal and spatial resolution of forest carbon dynamics and help resolve key scientific uncertainties, which we highlight in terms of evidence for forest greening (enhanced growth) versus browning (reduced growth, increased mortality). We describe jump-starting a tree-ring collection across the continent of North America, given the commitments of Canada, the United States, and Mexico to visit forest inventory plots, along with existing legacy collections. Failing to do so would be a missed opportunity to help chart an evidence-based path toward meeting national commitments to reduce net greenhouse gas emissions, urgently needed for climate stabilization and repair.
• Gao, S., Liang, E., Liu, R., Babst, F., Camarero, J. J., Fu, Y. H., Piao, S., Rossi, S., Shen, M., Wang, T., & Penuelas, J. (2022). An earlier start of the thermal growing season enhances tree growth in cold humid areas but not in dry areas. . Nature Ecology & Evolution, 322, 108996.
• Gao, S., Liang, E., Liu, R., Babst, F., Camarero, J. J., Fu, Y. H., Piao, S., Rossi, S., Shen, M., Wang, T., & Peñuelas, J. (2022). An earlier start of the thermal growing season enhances tree growth in cold humid areas but not in dry areas. Nature ecology & evolution, 6(4), 397-404.
  More info

  Climatic warming alters the onset, duration and cessation of the vegetative season. While previous studies have shown a tight link between thermal conditions and leaf phenology, less is known about the impacts of phenological changes on tree growth. Here, we assessed the relationships between the start of the thermal growing season and tree growth across the extratropical Northern Hemisphere using 3,451 tree-ring chronologies and daily climatic data for 1948-2014. An earlier start of the thermal growing season promoted growth in regions with high ratios of precipitation to temperature but limited growth in cold-dry regions. Path analyses indicated that an earlier start of the thermal growing season enhanced growth primarily by alleviating thermal limitations on wood formation in boreal forests and by lengthening the period of growth in temperate and Mediterranean forests. Semi-arid and dry subalpine forests, however, did not benefit from an earlier onset of growth and a longer growing season, presumably due to associated water loss and/or more frequent early spring frosts. These emergent patterns of how climatic impacts on wood phenology affect tree growth at regional to hemispheric scales hint at how future phenological changes may affect the carbon sequestration capacity of extratropical forest ecosystems.
• Kannenberg, S., Cabon, A., Babst, F., Belmecheri, S., Delpierre, N., & Guerrieri, R. (2022). Drought-induced decoupling between carbon uptake and tree growth impacts forest carbon turnover time. . Agricultural and Forest Meteorology, 322, 108996.
• Lu, X., Liang, E., Babst, F., Camarero, J. J., & Buentgen, U. (2022). Warming-induced tipping points of Arctic and alpine shrub recruitment. PNAS, 119, e2118120119.
• Lu, X., Liang, E., Babst, F., Camarero, J. J., & Büntgen, U. (2022). Warming-induced tipping points of Arctic and alpine shrub recruitment. Proceedings of the National Academy of Sciences of the United States of America, 119(9).
  More info

  Shrub recruitment, a key component of vegetation dynamics beyond forests, is a highly sensitive indicator of climate and environmental change. Warming-induced tipping points in Arctic and alpine treeless ecosystems are, however, little understood. Here, we compare two long-term recruitment datasets of 2,770 shrubs from coastal East Greenland and from the Tibetan Plateau against atmospheric circulation patterns between 1871 and 2010 Common Era. Increasing rates of shrub recruitment since 1871 reached critical tipping points in the 1930s and 1960s on the Tibetan Plateau and in East Greenland, respectively. A recent decline in shrub recruitment in both datasets was likely related to warmer and drier climates, with a stronger May to July El Niño Southern Oscillation over the Tibetan Plateau and a stronger June to July Atlantic Multidecadal Oscillation over Greenland. Exceeding the thermal optimum of shrub recruitment, the recent warming trend may cause soil moisture deficit. Our findings suggest that changes in atmospheric circulation explain regional climate dynamics and associated response patterns in Arctic and alpine shrub communities, knowledge that should be considered to protect vulnerable high-elevation and high-latitude ecosystems from the cascading effects of anthropogenic warming.
• Salom\'{o}n, R. L., Peters, R. L., Zweifel, R., Sass-Klaassen, U., Stegehuis, A. I., Smiljanic, M., Poyatos, R., Babst, F., Cienciala, E., Fonti, P., Lerink, B., Lindner, M., Martinez-Vilalta, J., Mencuccini, M., Nabuurs, G., Maaten, E., Arx, G., Bär, A., Akhmetzyanov, L., , Balanzategui, D., et al. (2022). The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests. Nature Communications, 13(1).
• Salomón, R. L., Peters, R. L., Zweifel, R., Sass-Klaassen, U. G., Stegehuis, A. I., Smiljanic, M., Poyatos, R., Babst, F., Cienciala, E., Fonti, P., Lerink, B. J., Lindner, M., Martinez-Vilalta, J., Mencuccini, M., Nabuurs, G. J., van der Maaten, E., von Arx, G., Bär, A., Akhmetzyanov, L., , Balanzategui, D., et al. (2022). The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests. Nature communications, 13(1), 28.
  More info

  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-temporal resolution dendrometer data from 21 species across 53 sites. Relative to the two preceding years, annual stem growth was not consistently reduced by the 2018 heatwave but stems experienced twice the temporary shrinkage due to depletion of water reserves. Conifer species were less capable of rehydrating overnight than broadleaves across gradients of soil and atmospheric drought, suggesting less resilience toward transient stress. In particular, Norway spruce and Scots pine experienced extensive stem dehydration. Our high-resolution dendrometer network was suitable to disentangle the effects of a severe heatwave on tree growth and desiccation at large-spatial scales in situ, and provided insights on which species may be more vulnerable to climate extremes.
• Zuidema, P., Babst, F., Groenendijk, P., Trouet, V., Abiyu, A., & Acuna-Soto, R. (2022). Dry-season climate variability is a major driver of tropical tree growth. . Nature Geoscience, 15, 269-276.
• Bose, A. K., Scherrer, D., Camarero, J. J., Ziche, D., Babst, F., Bigler, C., Bolte, A., {n}\'{a}n, I. D., Etzold, S., Fonti, P., Forrester, D. I., Gavinet, J., Gazol, A., Andr\'{e}s, E. G., Karger, D. N., Lebourgeois, F., L\'{e}vesque, M., Mart\'{\i}nez-Sancho, E., Menzel, A., , Neuwirth, B., et al. (2021). Climate sensitivity and drought seasonality determine post-drought growth recovery of Quercus petraea and Quercus robur in Europe. Science of The Total Environment, 784, 147222.
• Jeong, J., Barichivich, J., Peylin, P., Haverd, V., McGrath, M. J., Vuichard, N., Evans, M. N., Babst, F., & Luyssaert, S. (2021). Using the International Tree-Ring Data Bank (ITRDB) records as century-long benchmarks for global land-surface models. Geoscientific Model Development, 14(9), 5891--5913.
• Lu, X., Liang, E., Wang, Y., Babst, F., & Camarero, J. J. (2021). Mountain treelines climb slowly despite rapid climate warming. Global Ecology and Biogeography, 30(1), 305-315.
• Monson, R. K., Hu, J., Frank, D. C., Wright, J. E., Babst, F., Belmecheri, S., & Szejner, P. (2021). Stable isotopes of tree rings reveal seasonal-to-decadal patterns during the emergence of a megadrought in the Southwestern US. Oecologia, 197(4), 16. doi:doi.org/10.1007/s00442-021-04916-9
• Peñuelas, J., Camarero, J. J., Piao, S., Salerno, F., Zhu, H., Shen, M., Muhammad, S., Babst, F., Liang, E., Pandey, J., Sigdel, S. R., & Leavitt, S. W. (2021). No benefits from warming even for subnival vegetation in the Himalayas. Science Bulletin, 66(18), 1825–1829. doi:10.1016/j.scib.2021.06.005
• Sigdel, S. R., Pandey, J., Liang, E., Muhammad, S., Babst, F., Leavitt, S. W., Shen, M., Zhu, H., Salerno, F., Piao, S., Camarero, J. J., uelas, J. P. (2021). No benefits from warming even for subnival vegetation in the central Himalayas. Science Bulletin, 66(18), 1825--1829.
• Szejner, P., Belmecheri, S., Babst, F., Wright, W. E., Frank, D. C., Hu, J., & Monson, R. K. (2021). Stable isotopes of tree rings reveal seasonal-to-decadal patterns during the emergence of a megadrought in the Southwestern US. Oecologia.
• Trotsiuk, V., Babst, F., Grossiord, C., Gessler, A., Forrester, D. I., Buchmann, N., Schaub, M., & Eugster, W. (2021). Tree growth in Switzerland is increasingly constrained by rising evaporative demand. Journal of Ecology.
• Wang, Y., Liang, E., Lu, X., Camarero, J. J., Babst, F., Shen, M., uelas, J. P. (2021). Warming-induced shrubline advance stalled by moisture limitation on the Tibetan Plateau. Ecography, 44(11), 1631--1641.
• Babst, F. (2020). Assessing the response of forest productivity to climate extremes in Switzerland using model‐data fusion. Global Change Biology.
• Babst, F. (2020). Axial changes in wood functional traits have limited net effects on stem biomass increment in European beech (Fagus sylvatica). Tree Physiology.
• Babst, F. (2020). Continental‐scale tree‐ring‐based projection of Douglas‐fir growth: Testing the limits of space‐for‐time substitution. Global Change Biology.
• Babst, F. (2020). The PROFOUND Database for evaluating vegetation models and simulating climate impacts on European forests. Earth System Science Data.
• Babst, F. (2019). Past the climate optimum: Recruitment is declining at the world's highest juniper shrublines on the Tibetan Plateau. Ecology.
• Babst, F. (2019). Seasonal and synoptic climatic drivers of tree growth in the Bighorn Mountains, WY, USA (1654\textendash1983 CE). Dendrochronologia.
• Babst, F. (2019). The climatic drivers of primary\ Picea\ forest growth along the Carpathian arc are changing under rising temperatures. Global Change Biology.
• Babst, F. (2019). Twentieth century redistribution in climatic drivers of global tree growth. Science Advances.
• Alexander, M. R., Rollinson, C. R., Babst, F., Trouet, V., & Moore, D. (2018). Relative influences of multiple sources of uncertainty on cumulative and incremental tree-ring-derived aboveground biomass estimates. Trees-Structure and Function, 32(1), 265-276.
• Babst, F., Bodesheim, P., Charney, N., Friend, A. D., Girardin, M. P., Klesse, S., Moore, D., Seftigen, K., Bjorklund, J., Bouriaud, O., Dawson, A., DeRose, R. J., Dietze, M. C., Eckes, A. H., Enquist, B., Frank, D. C., Mahecha, M. D., Poulter, B., Record, S., , Trouet, V., et al. (2018). When tree rings go global: Challenges and opportunities for retro- and prospective insight. Quaternary Science Reviews, 197, 1-20.
• Klesse, S., Babst, F., Lienert, S., Spahni, R., Joos, F., Bouriaud, O., Carrer, M., Di Filippo, A., Poulter, B., Trotsiuk, V., Wilson, R., & Frank, D. C. (2018). A Combined Tree Ring and Vegetation Model Assessment of European Forest Growth Sensitivity to Interannual Climate Variability. Global Biogeochemical Cycles, 32(8), 1226-1240.
• Marchand, W., Girardin, M. P., Gauthier, S., Hartmann, H., Bouriaud, O., Babst, F., & Bergeron, Y. (2018). Untangling methodological and scale considerations in growth and productivity trend estimates of Canada's forests. Environmental Research Letters, 13(9).
• Seftigen, K., Frank, D. C., Bjorklund, J., Babst, F., & Poulter, B. (2018). The climatic drivers of normalized difference vegetation index and tree-ring-based estimates of forest productivity are spatially coherent but temporally decoupled in Northern Hemispheric forests. Global Ecology and Biogeography, 27(11), 1352-1365.
• Trouet, V., Babst, F., & Meko, M. (2018). Recent enhanced high-summer North Atlantic Jet variability emerges from three-century context. Nature Communications, 9.
• Zhang, Z., Babst, F., Bellassen, V., Frank, D., Launois, T., Tan, K., Ciais, P., & Poulter, B. (2018). Converging Climate Sensitivities of European Forests Between Observed Radial Tree Growth and Vegetation Models. Ecosystems, 21(3), 410-425.
• Belmecheri, S., Babst, F., Hudson, A. R., Betancourt, J., & Trouet, V. (2017). Northern Hemisphere Jet Stream Position Indices as Diagnostic Tools for Climate and Ecosystem Dynamics. Earth Interactions, 21, 1-23.
• Evans, M., Falk, D. A., Arizpe, A., Swetnam, T. L., Babst, F., & Holsinger, K. E. (2017). Fusing tree-ring and forest inventory data to infer influences on tree growth. Ecosphere, 8(7).
• Montane, F., Fox, A. M., Arellano, A. F., MacBean, N., Alexander, M. R., Dye, A., Bishop, D. A., Trouet, V., Babst, F., Hessl, A. E., Pederson, N., Blanken, P. D., Bohrer, G., Gough, C. M., Litvak, M. E., Novick, K. A., Phillips, R. P., Wood, J. D., & Moore, D. (2017). Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools, and turnover in temperate forests. Geoscientific Model Development, 10(9), 3499-3517.
• Wu, X., Liu, H., Li, X., Ciais, P., Babst, F., Guo, W., Zhang, C., Magliulo, V., Pavelka, M., Liu, S., Huang, Y., Wang, P., Shi, C., & Ma, Y. (2017). Differentiating drought legacy effects on vegetation growth over the temperate Northern Hemisphere.. Global change biology.
• Babst, F., Wright, W. E., Szejner, P., Wells, L., Belmecheri, S., & Monson, R. K. (2016). Blue intensity parameters derived from Ponderosa pine tree rings characterize intra-annual density fluctuations and reveal seasonally divergent water limitations. Trees-Structure and Function, 30(4), 1403-1415.
• Belmecheri, S., Babst, F., Wahl, E. R., Stahle, D. W., & Trouet, V. (2016). Multi-century evaluation of Sierra Nevada snowpack. Nature Climate Change, 6, 2-3.
• Szejner, P., Wright, W. E., Babst, F., Belmecheri, S., Trouet, V., Leavitt, S. W., Ehleringer, J. R., & Monson, R. K. (2016). Latitudinal gradients in tree ring stable carbon and oxygen isotopes reveal differential climate influences of the North American Monsoon System. Journal of Geophysical Research-Biogeosciences, 121(7), 1978-1991.
• Rammig, A., Wiedermann, M., Donges, J. F., Babst, F., Bloh, W., Frank, D., Thonicke, K., & Mahecha, M. D. (2015). Coincidences of climate extremes and anomalous vegetation responses: comparing tree ring patterns to simulated productivity. Biogeosciences, 12(2), 373-385.
• Babst, F., Bouriaud, O., Alexander, R., Trouet, V., & Frank, D. (2014). Toward consistent measurements of carbon accumulation: A multi-site assessment of biomass and basal area increment across Europe. Dendrochronologia, 32(2), 153-161.
• Wu, X., Babst, F., Ciais, P., Frank, D., Reichstein, M., Wattenbach, M., Zang, C., & Mahecha, M. D. (2014). Climate-mediated spatiotemporal variability in terrestrial productivity across Europe. Biogeosciences, 11(11), 3057-3068.
• Babst, F., Poulter, B., Trouet, V., Tan, K., Neuwirth, B., Wilson, R., Carrer, M., Grabner, M., Tegel, W., Levanic, T., Panayotov, M., Urbinati, C., Bouriaud, O., Ciais, P., & Frank, D. (2013). Site- and species-specific responses of forest growth to climate across the European continent. Global Ecology and Biogeography, 22(6), 706-717.
• Babst, F., Carrer, M., Poulter, B., Urbinati, C., Neuwirth, B., & Frank, D. (2012). 500 years of regional forest growth variability and links to climatic extreme events in Europe. Environmental Research Letters, 7(4).
• Wilmking, M., Hallinger, M., Van Bogaert, R., Kyncl, T., Babst, F., Hahne, W., Juday, G. P., Luis, M., Novak, K., & Voellm, C. (2012). Continuously missing outer rings in woody plants at their distributional margins. Dendrochronologia, 30(3), 213-222.
• Babst, F., Esper, J., & Parlow, E. (2010). Landsat TM/ETM plus and tree-ring based assessment of spatiotemporal patterns of the autumnal moth (Epirrita autumnata) in northernmost Fennoscandia. Remote Sensing of Environment, 114(3), 637-646.
• Babst, F., Mueller, R. W., & Hollmarm, R. (2008). Verification of NCEP reanalysis shortwave radiation with mesoscale remote sensing data. Ieee Geoscience and Remote Sensing Letters, 5(1), 34-37.

Presentations

• Babst, F. (2022, June). Where, when, and how: opportunities for forest monitoring networks to tackle scaling uncertainties. TreeNet 10-yr anniversary conference. Bad Bubendorf, Switzerland.
• Babst, F., Friend, A., Karamihalaki, M., Wei, J., von Arx, G., Papale, D., & Peters, R. (2022, May). Observations of carbon allocation in the world’s forests must match pace with vegetation model development. European Geoscience Union general assembly. Vienna, Austria.
• Babst, F., Gillan, J., Libantino-Norton, C., Devine, C., & van Leeuwen, W. (2022, April). Fusing terrestrial LiDAR and tree-ring observations to quantify and scale ecosystem structure and productivity for global change applications. Earth Dynamics Observatory meeting. Tucson.
• Klesse, S., Babst, F., Evans, M. E., Hurley, A., Pappas, C., & Peters, R. L. (2022, May). Drought legacy effects in radial tree growth are rarely significant under heightened statistical scrutiny. European Geoscience Union general assembly. Vienna, Austria.
• Wei, J., von Arx, G., Fan, Z., Ibrom, A., Mund, M., Knohl, A., Peters, R., & Babst, F. (2022, April). How much does carbon allocation to woody biomass change during drought episodes? Insights from two European beech forests. 7th Asian Dendro Conference. Zhuhai, China.
• Babst, F. (2021, 03). Is understanding the past enough to predict the future?. Departmental Colloquium of the Laboratory of Tree-Ring Research. Tucson: University of Arizona.
  More info

  Seminar
• Babst, F. (2021, 09). Hotspots of change in major tree species under global warming. RusDendro quadrennial meeting. Abakan, Russia (virtual).
• Babst, F. (2021, 09). The role of arid ecosystems in climate change mitigation depends on a carbon-energy trade-off. 2021 Symposium on Resilience Research for Global Development Challenges. University of Arizona: Arizona Institutes for Resilience.
• Babst, F. (2021, 11). An introduction to quantitative wood anatomy using ROXAS. International Youth Forum for Wood Anatomy. Chengdu, China (virtual).
• Babst, F., & Trouet, V. M. (2021, 04). Dry-season climate drives interannual variability in tropical tree growth. European Geosciences Union General Assembly. Vienna.
• Evans, M. E., DeRose, R. J., Klesse, S. M., Girardin, M., Heilman, K., Dietze, M., Shaw, J., Babst, F., Cahoon, S. M., Duchesne, L., Frank, D. C., Giebink, C., & Martinez-Gutierez, G. (2021). Enhanced Forest Ecosystem Monitoring for Carbon Accounting and Climate Mitigation: the Case for Adding Tree Rings to North American's National Forest Inventories. American Geophysical Union fall meeting. New Orleans.
• Babst, F., & Evans, M. E. (2020, August). Hotspots of change in major tree species under climate warming. Annual Meeting of the Ecological Society of America. held virtually: Ecological Society of America.
  More info

  Background/Question/MethodsWarming alters the variability and trajectories of tree growth around the world by intensifying or alleviating energy and water limitation. This insight from regional to global-scale research emphasizes the susceptibility of forest ecosystems and resources to climate change. However, globally-derived estimates are not necessarily meaningful for local nature conservation or management considerations, if they lack specific information on present or prospective tree species habitats. This is particularly the case towards the edge of their distribution, where shifts in growth trajectories may be imminent or already occurring. Importantly, the geographic space occupied by a tree species is not only constrained by climate, but often reflects biotic pressure such as competition for resources with other species. Hence, distinguishing climatic from competitive niche boundaries becomes a central challenge to identifying areas where tree species are most susceptible to climate change.Here, we employ a novel concept to characterize each position within a species’ bioclimatic niche based on two criteria: a climate sensitivity index (CSI) and a habitat occupancy index (HOI). The CSI is derived from step-wise multiple linear regression models that explain variability in annual radial tree growth as a function of monthly climate anomalies. The HOI is based on an ensemble of five species distribution models calculated from a combination of observed species occurrences and twenty-five bioclimatic variables.Results/ConclusionsWe calculated these two indices for 11 widespread tree species across the Northern Hemisphere. The combination of climate sensitivity and habitat suitability indicated hotspots of change, where tree growth is mainly limited by competition (low HOI and low CSI), as well as areas that are particularly sensitive to climate variability (low HOI and high CSI). In the former, we expect that forest management geared towards adjusting the competitive balance between several candidate species will be most effective under changing environmental conditions. In the latter areas, selecting particularly drought-tolerant accessions of a given species may reduce forest susceptibility to the predicted warming and drying.