About

Scott Saleska is a Professor of Ecology & Evolutionary Biology at the University of Arizona, holding a position since 2017. He also has a joint appointment with UA Soil Water and Environmental Sciences and is a faculty affiliate of the UA Institute of Environment. His research focuses on understanding how the structure and function of terrestrial vegetation and microbial communities regulate large-scale biogeochemical processes. As a global change ecologist, he investigates how ecological communities influence land surface interactions with the atmosphere and climate, from local to global scales. His work addresses the significant challenge of scaling biological information from individual organs or organisms to landscapes and ecosystems, utilizing tools from ecophysiology, ecosystem ecology, micrometeorology, atmospheric science, remote sensing, process-based modeling, and microbial meta-omics. His contributions aim to improve predictions of climate change impacts by elucidating the role of ecological communities in climate regulation.

Research topics

• Computer Science
• Biology
• Ecology
• Environmental science
• Geography
• Genetics
• Computational biology
• Evolutionary biology
• Atmospheric sciences
• Information Retrieval
• World Wide Web
• Climatology
• Data Mining
• Programming language
• Library science
• Botany
• Database
• Agroforestry
• Forestry
• Astronomy
• Data science
• Oceanography
• Materials science
• Physics

Selected publications

• Microbiome Adaptation Could Amplify Modeled Projections of Global Soil Carbon Loss With Climate Warming

  Global Change Biology · 2025-06-01 · 5 citations

  articleOpen access

  Warming alters soil microbial traits through ecological and evolutionary processes, directly influencing the decomposition of organic matter, which significantly affects global soil carbon emissions. Yet, soil carbon models largely ignore these processes and their implications for global responses to warming. Here, we incorporate eco-evolutionary theory into a mechanistic model describing microbial soil carbon decomposition to address the question of whether such processes could have consequential effects on climate carbon feedbacks globally. We assume that a key trait of microbes, their resource allocation to production of exoenzymes (which facilitate decomposition of organic matter)-is optimized to environmental temperatures by natural selection. We find that eco-evolutionary optimization results in microbes allocating more resources to enzyme production under warming. When applied at the global scale, eco-evolutionary optimization enhances the biological realism of soil carbon models and significantly amplifies global soil carbon loss by 2100. Our results highlight the significant potential of microbial eco-evolutionary responses to influence carbon cycle feedbacks to climate change, and motivate an urgent need for more comprehensive data to accurately quantify the adaptive potential of microbiomes in response to climate change.

  PublisherDOI

• From Archaea to the atmosphere: remotely sensing Arctic methane

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-13 · 2 citations

  preprint

  Abstract Global atmospheric methane concentrations are rapidly rising and becoming isotopically more depleted, implying an unresolved microbial contribution. Rising Arctic temperatures are variably altering soil methane cycling, causing consequential uncertainty in the atmospheric methane budget. We demonstrated in an Arctic wetland that below-ground microbiota and methane-cycling features parallelled above-ground plant communities. To upscale emissions, we applied machine learning to remote sensing data to identify habitats, which were assigned average emissions. To upscale dynamically, we incorporated climate data, remotely-sensed water table variation, and habitat classes into a temporally-resolved biogeochemical model, to predict methane flux and isotope dynamics. This accurately estimated more depleted 13C-methane than previously used for Arctic habitats in global source partitioning. Remote-sensing of these rapidly changing inaccessible landscapes can thus help constrain the role of the Arctic in ongoing changes in global methane emissions.

  PublisherDOI

• TROLL 4.0: representing water and carbon fluxes, leaf phenology, and intraspecific trait variation in a mixed-species individual-based forest dynamics model – Part 2: Model evaluation for two Amazonian sites

  Geoscientific model development · 2025-08-25 · 3 citations

  articleOpen access

  Abstract. TROLL 4.0 is an individual-based forest dynamics model that jointly simulates the structure, diversity, and functioning of tropical forests, including their water balance, carbon fluxes, and leaf phenology, while accounting for intraspecific trait variation for a large number of species. In a companion paper, we describe how the model represents the physiological and demographic processes that control the tree life cycle in a 1 m resolution spatially explicit scene and uses plant functional traits measurable in the field to parameterize such processes across species and individuals (Maréchaux et al., 2025). Here we evaluate the performance of TROLL 4.0 for two Amazonian sites with contrasting soil and climate properties. We assessed the model's ability to represent forest structure, composition, and dynamics using lidar-derived spatial distribution of top canopy height and forest inventories combined with information on plant functional traits. We also evaluated the model's ability to represent carbon and water fluxes, as well as leaf area variation, at daily and fortnightly resolution over a decade, using detailed information from on-site eddy covariance towers, satellite data, and ground-based or airborne lidar data. We finally compared the responses of carbon and water fluxes to environmental drivers between simulated and observed data. Overall, TROLL 4.0 provided a realistic representation of forests at both sites. The simulated canopy height distribution showed a high correlation coefficient (CC) with observed aerial and satellite data (CC > 0.92), while the species and functional composition were well represented (CC > 0.75). TROLL 4.0 also realistically simulated the seasonal variability of carbon and water fluxes (CC > 0.46) and their responses to environmental drivers, while capturing temporal variations in leaf area (CC > 0.76) and its partitioning into leaf age cohorts. However, TROLL 4.0 overestimated annual gross primary productivity at both sites (mean RMSEP = 0.94 ± 0.67 kgC m−2 yr−1) and evapotranspiration at one site (mean RMSEP = 0.75 ± 0.63 mm d−1), likely due to an underestimation of the soil water depletion and stomatal control during the dry season. This evaluation highlights the potential of TROLL 4.0 to represent ecosystem fluxes and the structure, diversity, and dynamics of plant communities at a fine resolution, paving the way for model predictions of the effects of climate change, fragmentation, and forest management on forest structure and dynamics.

  PublisherOA PDFDOI

• Seeing Forests Through Clouds: Comment on "Recent global temperature surge amplified by record-low planetary albedo" (arXiv:2405.19986)

  ArXiv.org · 2025-01-28 · 2 citations

  preprintOpen accessSenior author

  Goessling et al. (1) link the record-breaking warming anomaly of 2023 to a global albedo decline due to reduced low-level cloud cover. What caused the reduction remains unclear. Goessling et al. considered several geophysical mechanisms, including ocean surface warming and declining aerosol emissions, but did not discuss the biosphere. We propose that disruption of global biospheric functioning could be a cause, as supported by three lines of evidence that have not yet been jointly considered.

  PublisherOA PDFDOI

• What is Endangered now? Climate Science at the Crossroads

  2025-07-31

  preprintOpen access1st authorCorresponding

  The greenhouse gas “endangerment finding” of the U.S. Environmental Protection Agency (EPA), established in 2009 after a 2006 U.S. Supreme Court case (Massachusetts vs EPA) in which we participated as amicus curiae (friends of the court) , has become the basis for U.S. regulation of greenhouse gases in the years since. The current Administration of President Donald Trump is now seeking its repeal. Here, we review the role climate science played in that 2006 case, and how the scientific evidence that undergirds the endangerment finding has gotten stronger in the 16 years since. Finally, we consider what will be the fate of the endangerment finding – and indeed that of role of science in contributing to policy – in light of the current challenging environment for science in the U.S.

  PublisherOA PDFDOI

• Trait coordination reveals the fast–slow plant economics spectrum along the vertical canopy profile in central Amazonian forests

  Functional Ecology · 2025-11-08

  articleOpen access

  Abstract Understanding how environmental drivers affect tree functioning is essential to improve predictions of tropical forests' response to climate change. While functional traits directly influence tree performance, our understanding of how canopy environments shape their coordination and variation along the vertical forest profile remains limited. We quantified annual growth rates in terms of above‐ground biomass (AGB), the maximum efficiency of photosystem II (Fv/Fm) and six tree functional traits related to water transport (xylem density and Huber value), leaf morphology (leaf size, angle and stomatal density) and photosynthesis (specific leaf area) along the vertical forest profile in an old‐growth central Amazonian forest. To investigate the influence of canopy environments and ontogenetic stages on the variation of these traits, we divided the forest into three vertical strata defined by height from the ground (S1: 0–20 m; S2: 20–40 m; S3: >40 m). We sampled 162 branches and 486 leaves from 54 trees of 10 species, encompassing at least five of the most abundant species per stratum. Path analysis and correlation matrices were used to explore the links between canopy environments, traits and the ‘fast–slow’ plant economics spectrum. We found significant effects of height on relative tree growth, leaf size and specific leaf area. Trait correlations varied across strata suggesting an ecological stratification of canopy functional niches. Trait–growth correlations increased in number and strength with increasing height, suggesting greater trait‐mediated growth control in large trees. Our results reveal how traits and strategies on the ‘fast–slow’ plant economics spectrum are vertically distributed and coordinated along the forest profile. Our findings highlight important interactions between species and canopy environments in determining plant traits, with emergent species showing adaptive strategies at different stages of their development. Read the free Plain Language Summary for this article on the Journal blog.

  PublisherOA PDFDOI

• A framework for integrating genomics, microbial traits, and ecosystem biogeochemistry

  Nature Communications · 2025-03-04 · 27 citations

  articleOpen access

  Microbes drive the biogeochemical cycles of earth systems, yet the long-standing goal of linking emerging genomic information, microbial traits, mechanistic ecosystem models, and projections under climate change has remained elusive despite a wealth of emerging genomic information. Here we developed a general genome-to-ecosystem (G2E) framework for integrating genome-inferred microbial kinetic traits into mechanistic models of terrestrial ecosystems and applied it at a well-studied Arctic wetland by benchmarking predictions against observed greenhouse gas emissions. We found variation in genome-inferred microbial kinetic traits resulted in large differences in simulated annual methane emissions, quantitatively demonstrating that the genomically observable variations in microbial capacity are consequential for ecosystem functioning. Applying microbial community-aggregated traits via genome relative-abundance-weighting gave better methane emissions predictions (i.e., up to 54% decrease in bias) compared to ignoring the observed abundances, highlighting the value of combined trait inferences and abundances. This work provides an example of integrating microbial functional trait-based genomics, mechanistic and pragmatic trait parameterizations of diverse microbial metabolisms, and mechanistic ecosystem modeling. The generalizable G2E framework will enable the use of abundant microbial metagenomics data to improve predictions of microbial interactions in many complex systems, including oceanic microbiomes.

  PublisherDOI

• Unveiling the integration of above- and below-ground tree carbon-hydraulic traits in Amazonian trees across hydrological niches

  Tree Physiology · 2025-06-03 · 1 citations

  articleOpen accessSenior author

  Understanding trait coordination and trade-offs along the root-to-leaf hydraulic pathway is critical for assessing forest functioning, as these traits significantly impact ecosystem carbon allocation and water use. Here, we investigated the relationship between carbon and hydraulic traits in 11 Amazonian tree species distributed across vertically structured hydrological niches. Using a carbon-hydraulic framework, we tested the hypothesis that interspecific differences arise from the optimization of xylem hydraulic efficiency, reflecting how tropical trees balance water transport efficiency with the carbon costs of maintaining transport tissues across vertical canopy positions. Our results show that above-ground traits were largely explained by canopy position (vertical stratification), whereas below-ground carbon-hydraulic traits were predominantly influenced by interspecific differences. Upper canopy trees exhibited lower and less variable specific root length (SRL) than shallow-rooted understory trees, indicating divergent carbon allocation strategies. Thicker terminal roots had higher hydraulic conductivity (Ks) than finer roots, but Ks declined from roots to terminal branches in most species. Additionally, branch and leaf Ks increase with tree size, indicating greater hydraulic efficiency in larger canopy species. Below-ground, we presented evidence that an increase in SRL is linked to decreased hydraulic conductivity and is influenced by root diameter. Above-ground, branch and leaf hydraulic conductivity tend to be higher in species with higher wood density, which are also more prevalent in upper canopy layers. Together, our findings reveal a coordinated above- and below-ground carbon-hydraulic trait framework across Amazonian trees. Species that occupy different vertical above-ground hydrological niches in lowland Amazon forests exhibit different carbon allocation strategies, which helps explain variation in species dominance and resource use throughout the vertical forest profile.

  PublisherOA PDFDOI

• Technical note: Lys-clim, a combination of lysimeters and an atmospheric conditions simulator to study biogeochemical processes in the shallow critical zone

  2025-10-13

  articleOpen access

  Abstract. Studying the Critical Zone (CZ), i.e. the outermost envelope of Earth, and its bio-geochemical processes requires an interdisciplinary approach. The deployment of critical zone observatories has led to significant scientific advances but does not offer the possibility of comparing treatments or apprehending different climatic scenarios. Conversely, mesocosm studies are often discipline-specific and can be limited in scope. Here, we propose a complementary approach that relies on the combination of 15 lysimeters and a climate chamber. The lysimeters have been equipped to allow for a detailed monitoring of the water flow, which connects most biogeochemical processes in the critical zone. This monitoring relies on scales, tipping buckets, soil moisture sensors and a facilitated high frequency sampling of discharge water. Besides, in-situ continuous gas analysis is enabled by a 45-channel manifold. The climate simulator is a 81 m3 isolated chamber that enables regulation of temperature; atmospheric CO2; relative humidity; quantity and quality of irrigation water and quantity and quality of light. We evaluate the design in terms of its ability to assess the interactions between CZ processes. The main advantages of this set-up are as follows: it allows for the simulation of future climates or extreme events; it enables replication and the application of different treatments, facilitating the isolation of processes and the assessment of anthropogenic impacts; and it provides automated data acquisition.

  PublisherOA PDFDOI

• Biosphere 2’s latest mission: Learning how life first emerged on Earth – and how to make barren worlds habitable

  2025-09-23

  articleOpen access1st authorCorresponding
  PublisherDOI

Recent grants

• Collaborative Research: Are Amazon forest trees source or sink limited? Mapping hydraulic traits to carbon allocation strategies to decipher forest function during drought

  NSF · $1.2M · 2018–2023

• Collaborative Research: Airborne LIDAR Surveys of Forest Canopy Structure Across Amazonian Landscapes to Infer Large-scale Forest Biomass and Carbon Balance

  NSF · $309k · 2007–2010

• PIRE: Carbon, Water and Vegetation Dynamics of Amazon Forests Under Climatic Variability and Change

  NSF · $2.6M · 2007–2015

• Collaborative Research: Investigating Northern Peatland Methane Dynamics by Synthesizing Measurements, Remote Sensing and Modeling from Local to Regional to Continental Scales

  NSF · $380k · 2013–2017

• Collaborative Research: The other side of tropical forest drought: Do shallow water table regions of Amazonia act as large-scale hydrological refugia from drought?

  NSF · $346k · 2020–2024

Frequent coauthors

• P. M. Crill

  Stockholm University

  154 shared

• Natalia Restrepo‐Coupé

  University of Arizona

  101 shared

• Steven C. Wofsy

  95 shared

• Virginia I. Rich

  The Ohio State University

  93 shared

• Plínio Barbosa de Camargo

  Universidade de São Paulo

  83 shared

• Lucy R. Hutyra

  Boston University

  79 shared

• J. William Munger

  Harvard University Press

  76 shared

• W. J. Riley

  Lawrence Berkeley National Laboratory

  63 shared

Awards & honors

• Elected Fellow of the Ecological Society of America (2019)
• Agnese Nelms Haury Faculty Fellow in Environment and Social…
• NSF Doctoral Dissertation Grantee (1996-1998)
• NASA Global Change Fellow (1994-1997)