About

Professor Elsa Cleland leads research that evaluates ecological and evolutionary responses to global change at multiple scales, ranging from individual plants to ecosystem-level processes. Her work is grounded in the unifying concept of plant functional traits, which reflect trade-offs in ecological and evolutionary strategies. These traits integrate species' responses to their environment as well as their impact on ecosystem processes. The research primarily focuses on native and invasive plants in Southern California ecosystems. The lab employs diverse methods including field experiments, laboratory studies, data synthesis, and observations along natural gradients. A particular trait of interest in Professor Cleland's research is phenology, or seasonal timing, which influences many aspects of plant ecology and evolution. Recent projects under her leadership include community-engaged science initiatives addressing climate change adaptation and studies on how competition influences selection on germination timing. Her work also encompasses conservation efforts that aim to understand adaptive mechanisms to maximize species persistence amid accelerating climate change and habitat loss.

Research topics

• Environmental science
• Biology
• Ecology
• Chemistry
• Agronomy
• Environmental chemistry
• Agroforestry
• Mathematics
• Geography
• Atmospheric sciences

Selected publications

• Automated Quantification of Fine Root Production from Minirhizotron Image Time Series (Data)

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-01

  articleOpen accessSenior author

  Minirhizotron training and validation image datasets for the GINGER image pipeline, from the the paper "Automated Quantification of Fine Root Production from Minirhizotron Image Time Series" (Methods in Ecology and Evolution, 2026). - Dataset A was acquired in an alpine grassland at 2480m elevation in the Swiss Alps- Dataset B was acquired in a drained coastal fen peatland in north-eastern Germany- Dataset C was acquired in multiple beech forests in north-eastern Germany and north-western Poland For additional information about the data collection please refer to the methods section in the paper. Each dataset contains 3 folders:- "standingcrop" contains training image and annotation pairs for simple detection of all roots in an image.- "newgrowth" contains training input image pairs (x0 and x1) and annotations for the detection of newly grown roots.- "validation" has the same layout as "newgrowth" and is used to validate the method. Please see https://github.com/alexander-g/GINGER for the most recent version of the method source code. Usage instructions can be found in the github Readme and the paper supplement file. The corresponding author can provide additional technical support.

  PublisherDOI

• Automated Quantification of Fine Root Production from Minirhizotron Image Time Series (Code)

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-23

  otherOpen accessSenior author

  Software version as used in the publication "Automated Quantification of Fine Root Production from Minirhizotron Image Time Series" (Methods in Ecology and Evolution, 2026). For the most recent version please go to https://github.com/alexander-g/GINGER

  PublisherDOI

• Automated Quantification of Fine Root Production from Minirhizotron Image Time Series (Data)

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-01

  articleOpen accessSenior author

  Minirhizotron training and validation image datasets for the GINGER image pipeline, from the the paper "Automated Quantification of Fine Root Production from Minirhizotron Image Time Series" (Methods in Ecology and Evolution, 2026). - Dataset A was acquired in an alpine grassland at 2480m elevation in the Swiss Alps- Dataset B was acquired in a drained coastal fen peatland in north-eastern Germany- Dataset C was acquired in multiple beech forests in north-eastern Germany and north-western Poland For additional information about the data collection please refer to the methods section in the paper. Each dataset contains 3 folders:- "standingcrop" contains training image and annotation pairs for simple detection of all roots in an image.- "newgrowth" contains training input image pairs (x0 and x1) and annotations for the detection of newly grown roots.- "validation" has the same layout as "newgrowth" and is used to validate the method. Please see https://github.com/alexander-g/GINGER for the most recent version of the method source code. Usage instructions can be found in the github Readme and the paper supplement file. The corresponding author can provide additional technical support.

  PublisherDOI

• Can species adapt to drought using multiple strategies? Lessons from the California poppy

  New Phytologist · 2026-04-02

  articleOpen accessSenior author

  Plants can escape drought by completing life cycles early, tolerate drought by increasing physiological limits, or avoid drought stress by obtaining or using water more efficiently. It remains unclear whether strategies vary within species across their distributional ranges due to trade-offs, and whether species can exhibit plasticity in multiple traits simultaneously. We grew 19 populations of Eschscholzia californica collected along an aridity gradient in a glasshouse with high or low water, then applied a terminal drought treatment, and measured the responses of growth and functional traits. We found clinal variation in drought adaptation strategies; populations from arid sites exhibited escape phenotypes, while populations from mesic areas exhibited avoidance phenotypes. In response to low water, plants displayed plasticity in traits associated with both avoidance and tolerance strategies, and this plasticity was expressed consistently across populations. By contrast, specific root length (SRL) displayed clinal variation in plasticity; more arid sites had higher SRL (longer/thinner roots), and SRL increased the most in response to low water in the populations from arid sites. Our experiment demonstrates that frameworks developed to predict interspecific variation in drought adaptation strategies can also operate intraspecifically, with implications for wildflower conservation in the face of increasingly frequent droughts.

  PublisherDOI

• Automated Quantification of Fine Root Production from Minirhizotron Image Time Series (Code)

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-23

  otherOpen accessSenior author

  Software version as used in the publication "Automated Quantification of Fine Root Production from Minirhizotron Image Time Series" (Methods in Ecology and Evolution, 2026). For the most recent version please go to https://github.com/alexander-g/GINGER

  PublisherDOI

• Moderate burn severity, invasive competitors, and herbivory reduce post-fire shrub recovery in semi-arid shrubland

  Fire Ecology · 2026-05-07

  articleOpen accessSenior author

  Abstract Background Semi-arid shrublands in Mediterranean type ecosystems are increasingly vulnerable to altered fire regimes, with some sites recovering to native shrub dominance while others undergo vegetation type conversion by invasive herbaceous species. Many factors could influence post-fire vegetation recovery in the years immediately following fire, including the identity of initially colonizing species, climate (e.g. drought), and herbivore-induced mortality. The relative importance of these factors, and how they interact to influence vegetation recovery, is unknown. Methods This study investigated coastal sage shrub recovery following a 2021 wildfire; pre-fire the site was dominated by evergreen shrubs, with almost complete loss of vegetation during the fire. The experiment manipulated rainfall (with drought shelters) and mammalian herbivory (with exclosures), in adjacent sites that experienced differing fire severity (severe, moderate, and unburned). Results Plots with high burn severity had higher shrub seedling establishment and survival, lower initial invasive cover, and greater recovery of evergreen shrub cover (70%) after four years than plots that experienced a moderate burn (which achieved 25% evergreen shrub cover after four years). Structural equation modeling found evidence for both direct and indirect effects of fire severity on shrub recovery: moderate fire severity increased post-fire invasive cover which suppressed shrub recruitment. This finding highlights the importance of both burn severity and post-fire competition for determining the trajectory of post-fire vegetation recovery in semi-arid shrubland ecosystems. Mammalian herbivory significantly suppressed seedling recruitment and survival regardless of burn severity. By 2024, survival in moderate burn exclosures was about eight times higher than in open plots and doubled in severe burn plots. Drought treatments did not significantly affect shrub cover, recruitment, or survival, despite significantly reducing soil moisture. Conclusions Altogether, our results suggest that high severity fires can promote faster shrub recovery than moderate fires, but only if seedlings do not experience intense herbivory. Our findings further reveal the importance of integrated management strategies that address prescribed fire, herbivory, and invasive species to enhance vegetation recovery in fire-prone shrublands.

  PublisherDOI

• Automated quantification of fine root production from minirhizotron image time series

  Methods in Ecology and Evolution · 2026-02-09

  articleOpen accessSenior author

  Abstract Plant root growth accounts for a major part of the net primary production in grassland and forest ecosystems and influences the global carbon and nutrient cycles. Measuring the production of roots is inherently difficult, prone to inconsistencies and time‐consuming. Notably, there are currently no methods yet to automate this task. We have developed GINGER, a new method for automated estimation of the fine root production from a time series of minirhizotron images. It compares pairs of consecutive images with each other, separating new root growth from standing crop. The method was evaluated on four datasets from grassland, drained fen peatland and forest ecosystems. It exhibits performance on a similar level to that of human annotators while substantially reducing the time required for the data analysis. Human annotators showed a significant degree of variability among each other, confirming that the task is subjective and error‐prone. For demonstration, this pipeline was applied on two real‐world image datasets, spanning 2 and 3 years, to compute the total annual root production. End‐to‐end, including annotation and model training, GINGER reduced the required human workload from several thousand to less than 40 work hours. It could allow to scale up monitoring efforts and enable full automation in the future.

  PublisherOA PDFDOI

• Author response for "Automated Quantification of Fine Root Production from Minirhizotron Image Time Series"

  2025-12-23

  peer-reviewSenior author
  PublisherDOI

• Effects of elevated nutrient supply on litter decomposition are robust to impacts of mammalian herbivores across diverse grasslands

  Oecologia · 2025-09-13

  articleOpen access

  Litter decomposition is one of the largest carbon (C) fluxes in terrestrial ecosystems and links aboveground biomass to soil C pools. In grasslands, decomposition drivers have received substantial attention but the role of grassland herbivores in influencing decay rates is often ignored despite their potentially large effects on standing biomass and nutrient cycling. Recent work has demonstrated that nutrient addition increases early-stage decay and suppresses late-stage decay. Mammalian herbivores can mediate the effects of nutrient supply on biomass, suggesting herbivores may alter the effects of nutrients on decomposition, though this is largely unknown. We examined how herbivory mediates the effects of nutrient supply on long-term decomposition across 19 grassland sites of the Nutrient Network distributed experiment. At each site, a full-factorial experiment of combined nitrogen (N), phosphorus (P), and micronutrient (K) enrichment ('control' or ' + NPK') and mammalian herbivore (> ~ 50 g) exclusion ('unfenced' or 'fenced') was carried out in a randomized block design. We hypothesized that nutrient effects on litter decomposition would be strongest where herbivores caused the greatest reductions in aboveground plant biomass (i.e., at sites with more intense herbivory). After accounting for wide variation in decomposition rates across sites, we found that, within sites, elevated nutrients increased early-stage decay and suppressed late-stage decay. In contrast, neither herbivore exclusion (i.e., fencing) nor site level changes in aboveground biomass due to herbivory altered the nutrient effects on decomposition rates. Across grasslands, our results indicate that elevated nutrient supply modifies litter decomposition rates independent of herbivore impacts.

  PublisherOA PDFDOI

• Interactions among nutrients govern the global grassland biomass–precipitation relationship

  Proceedings of the National Academy of Sciences · 2025-04-11 · 11 citations

  articleOpen access

  Ecosystems are experiencing changing global patterns of mean annual precipitation (MAP) and enrichment with multiple nutrients that potentially colimit plant biomass production. In grasslands, mean aboveground plant biomass is closely related to MAP, but how this relationship changes after enrichment with multiple nutrients remains unclear. We hypothesized the global biomass-MAP relationship becomes steeper with an increasing number of added nutrients, with increases in steepness corresponding to the form of interaction among added nutrients and with increased mediation by changes in plant community diversity. We measured aboveground plant biomass production and species diversity in 71 grasslands on six continents representing the global span of grassland MAP, diversity, management, and soils. We fertilized all sites with nitrogen, phosphorus, and potassium with micronutrients in all combinations to identify which nutrients limited biomass at each site. As hypothesized, fertilizing with one, two, or three nutrients progressively steepened the global biomass-MAP relationship. The magnitude of the increase in steepness corresponded to whether sites were not limited by nitrogen or phosphorus, were limited by either one, or were colimited by both in additive, or synergistic forms. Unexpectedly, we found only weak evidence for mediation of biomass-MAP relationships by plant community diversity because relationships of species richness, evenness, and beta diversity to MAP and to biomass were weak or opposing. Site-level properties including baseline biomass production, soils, and management explained little variation in biomass-MAP relationships. These findings reveal multiple nutrient colimitation as a defining feature of the global grassland biomass-MAP relationship.

  PublisherDOI

Recent grants

• The influence of plant functional traits on ecosystem responses to altered rainfall

  NSF · $466k · 2012–2018

Frequent coauthors

• Scott L. Collins

  University of New Mexico

  46 shared

• Katharine N. Suding

  Institute of Arctic and Alpine Research

  44 shared

• W. Stanley Harpole

  Helmholtz Centre for Environmental Research

  41 shared

• Steven C. Pennings

  University of Houston

  39 shared

• Christopher B. Field

  Palo Alto Institute

  38 shared

• Katherine L. Gross

  38 shared

• Eric W. Seabloom

  University of Minnesota

  36 shared

• Elizabeth T. Borer

  University of Minnesota

  35 shared