Flipping through field notebooks…
Investigates how plant functional traits — from leaf venation to woody stem architecture — vary across climate gradients, scale from individual plants to ecosystems, and respond to drivers like drought and elevated CO2.
Plants in mountain landscapes like the Gunnison Basin live at the edge of what is physiologically possible. Short growing seasons, deep winter snowpack, cold nights, and an early-summer dry period between snowmelt and the arrival of monsoon rains all shape which species occur where, how they grow, and how much carbon they pull from the atmosphere. Research on plant trait variation, scaling, and climate responses tries to understand these patterns by measuring functional traits — measurable features of leaves, stems, and roots that influence how a plant captures resources and tolerates stress — and connecting them to climate, evolutionary history, and ecosystem processes.
A few key ideas anchor this work. Trait-based ecology uses traits such as leaf mass per area, vein density, plant height, and root architecture as a common currency to compare very different species and predict how communities will reorganize under climate change. Trait filtering refers to the way harsh environments allow only certain trait values to persist: a high-elevation meadow, for example, may screen out tall, thin-leaved species and favor short, tough-leaved ones. Leaf venation networks — the branching pattern of veins that delivers water inside a leaf — are particularly informative because vein density links a plant's water budget to climate. Phylogenetic diversity measures how much evolutionary history is packed into a community, and phylogenetic signal describes whether closely related species tend to share similar traits.
Several climate concepts also matter for the Gunnison Basin. The foresummer drought is the dry window between snowmelt in May and the start of the summer monsoon in July, and its severity is increasing as snow melts earlier. CO2 fertilization refers to the boost plants can get from rising atmospheric carbon dioxide, which may partially offset drought stress through improved water-use efficiency. Climate zonation groups landscapes into regions with similar climatic constraints on growth, and boreal greening is the once-expected idea that warming would simply make northern forests grow faster — an idea that recent work has complicated.
Early studies in the late 2000s established that mountains are natural laboratories for testing how biodiversity responds to climate. Working along an elevation gradient near RMBL, Bryant and colleagues showed that plants peak in richness and phylogenetic diversity at mid-elevations while soil bacteria decline monotonically with elevation, and that plant communities become more phylogenetically overdispersed — containing more distantly related species — as elevation rises . This finding established that elevation gradients filter plant lineages in patterned, predictable ways.
Environmental processes that filter trait values admitted by changing abiotic and biotic conditions, maintaining trait distributions through phenotypi...
The tendency for related species to resemble each other more than expected by chance, measured by Blomberg's K and Pagel's lambda
Enhanced plant growth due to increased atmospheric carbon dioxide concentrations
A measure of the evolutionary history represented in an ecological community, calculated as the sum of branch lengths connecting species in a phylogen...
The branching network of veins within a leaf that transports water and nutrients, characterized by vein density measurements
Approach using organism functional traits to understand ecological patterns and predict responses to environmental change
Decrease in compositional similarity between communities with increasing geographic distance or environmental separation
A standardized protocol for preparing plant leaves through chemical clearing and measuring vein density using microscopy and stochastic line-intersect...
Calculation of species area of occupancy (AOO) using filtered GBIF occurrence records and standardized grid-based methods following IUCN guidelines fo...
Genotyping using a panel of 384 candidate-gene single nucleotide polymorphisms putatively associated with adaptive traits.
Multiple candidate models incorporating different combinations of climate predictors were fitted and ranked using Akaike Information Criterion to sele...
Statistical validation approach for model selection and parameter optimization to ensure robust performance.
Studies of size-related plant traits have established a suite of mathematical functions describing whole plant investment and allocation. In parallel,...
This dataset contains abundance and range size data for angiosperm communities at three sites in Washington Gulch near the Rocky Mountain Biological L...
Predicting long-term trends in forest growth requires accurate characterisation of how the relationship between forest productivity and climatic stres...
Genomic selection (GS) is of interest in breeding because of its potential for predicting the genetic value of individuals and increasing genetic gain...
In fire-prone ecosystems, two important alternative fates for leaves are burning in a wildfire (when alive or as litter) or they get consumed (as litt...
Around the same time, dendrochronology research in the Gunnison Basin demonstrated that climate exerts strong, species-specific controls on woody plant growth. Poore and colleagues found that ring widths of mountain big sagebrush correlated strongly and negatively with summer temperature and positively with winter precipitation and maximum snow depth, implying that warmer, drier futures will reduce sagebrush growth and potentially shrink its range (Poore et al., 2009). Together, these early studies framed two enduring questions: how do traits and evolutionary history sort species along mountain gradients, and how sensitive is plant growth to the climate variables that are changing fastest?
A central result across this body of work is that leaf venation networks encode climate. Blonder and Enquist showed that community-mean vein density predicts growing season temperature and atmospheric CO2 with high accuracy, with vein density varying tenfold across leaves and declining with elevation within climate gradients (Blonder & Enquist, 2014). Follow-up work in quaking aspen demonstrated that the leaf economics spectrum — the global trade-off between fast, cheap leaves and slow, durable ones — emerges even within single clones, and that vein density between clones tracks summer temperature, precipitation, and elevation (Blonder et al., 2013). These results push the scale of trait-climate coupling down to the individual plant and link it mechanistically to water transport.
At the community and continental scale, traits and climate interact in ways that defy simple expectations. Lamanna and colleagues found that the functional diversity of trees decreases with latitude at the local scale but peaks at mid-latitudes when measured across whole regions, results that contradict simple environmental filtering predictions (Lamanna et al., 2014). Simova and colleagues showed that woody and herbaceous plants respond to climate differently: woody assemblages show strong climate signals in trait means and variances, while herbaceous species show weaker, more variable relationships (Simova et al., 2018). Forecasts that incorporate these climate sensitivities project major reorganizations of North American forests, with continent-wide growth declines of 6 to 19 percent under different emissions scenarios, a 72 percent improvement in water-use efficiency required to offset the worst case, and the disappearance of the simple boreal greening signal once shifting climate sensitivities are accounted for (Charney et al., 2016).
Locally at RMBL, the foresummer drought has emerged as a master variable for ecosystem carbon balance. Sloat and colleagues used eleven years of carbon flux data combined with watering experiments to show that the June drought index explained 77 percent of variation in peak-season net ecosystem productivity, that earlier snowmelt was tightly linked to lower carbon uptake, and that the timing of growing-season water — not the total amount — controls how much carbon subalpine meadows take up (Sloat et al., 2015). Plants stressed by the foresummer drought continued to show reduced carbon uptake even after monsoon rains arrived, suggesting legacy effects of early-season water stress.
Research since 2020 has shifted toward finer-scale questions about how traits, evolutionary history, and water relations interact under warming. Lenis used a reciprocal transplant experiment along the Washington Gulch elevation gradient to ask how rarely studied herbaceous species manage water, finding that leaf water potential becomes more negative at warmer, lower-elevation sites and is tightly coupled to stomatal behavior, even though soil moisture itself did not vary strongly along the gradient (Lenis, 2022). Veldhuisen and colleagues have brought phylogenetic tools to bear on subalpine meadows, showing that rare species — whether locally scarce or geographically restricted — do not contribute disproportionately to the evolutionary diversity of these communities, suggesting that commonness and rarity are partly decoupled from deep evolutionary history (Veldhuisen et al., 2025). A companion thesis extends this work to seasonal and spatial variation in phylogenetic diversity across RMBL (Veldhuisen, 2025).
Broader floristic inventories are also expanding the regional context for trait research. A recent vascular flora of nearby wilderness areas documented over 600 taxa and produced new records that refine our understanding of where rare and sensitive species occur in the southern Rockies (Rose, 2024). The field is moving toward integrating individual-level trait measurements, phylogenetic information, and long-term climate manipulations to predict how mountain plant communities will reassemble under continued warming.
Several large questions remain. How tightly will gains from CO2 fertilization track losses from drought stress in semi-arid mountain systems, given that even a 72 percent improvement in water-use efficiency may not offset projected growth declines? Can vein density and other leaf traits be used as reliable proxies to forecast which species will persist in a given climate zone, and do these relationships hold for herbaceous species as well as woody ones? How will the foresummer drought interact with shifting phenology to alter species composition, and will rare species — which appear redundant in evolutionary terms but may carry unique functional traits — buffer or amplify these changes? Answering these questions will require linking the trait, phylogenetic, and carbon-flux datasets already established at RMBL to longer time series and more reciprocal transplant experiments across the Gunnison Basin.
Blonder, B., & Enquist, B. J. (2014). Inferring climate from angiosperm leaf venation networks. New Phytologist. →
Blonder, B., Violle, C., & Enquist, B. J. (2013). Assessing the causes and scales of the leaf economics spectrum using venation networks in Populus tremuloides. Journal of Ecology. →
Bryant, J. A., Lamanna, C., Morlon, H., Kerkhoff, A. J., Enquist, B. J., & Green, J. L. (2008). Microbes on mountainsides: contrasting elevational patterns of bacterial and plant diversity. PNAS. →
Charney, N. D., Babst, F., et al. (2016). Observed forest sensitivity to climate implies large changes in 21st century North American forest growth. Ecology Letters. →
Lamanna, C., Blonder, B., Violle, C., Kraft, N. J. B., et al. (2014). Functional trait space and the latitudinal diversity gradient. PNAS. →
Lenis, M. (2022). The Impacts of Changing Temperature on Plant Water Use. →
Poore, R. E., Lamanna, C. A., Ebersole, J. J., & Enquist, B. J. (2009). Controls on radial growth of mountain big sagebrush and implications for climate change. Western North American Naturalist. →
Rose, J. (2024). Vascular Flora of the Powderhorn & La Garita Wilderness Areas and Adjacent Lands. CU Scholar. →
Simova, I., et al. (2018). Spatial patterns and climate relationships of major plant traits in the New World differ between woody and herbaceous species. Journal of Biogeography. →
Sloat, L. L., Henderson, A. N., Lamanna, C., & Enquist, B. J. (2015). The effect of the foresummer drought on carbon exchange in subalpine meadows. Ecosystems. →
Veldhuisen, R. (2025). Spatial and Temporal Variation in Phylogenetic Diversity in Rocky Mountain Plant Communities. UA Campus Repository. →
Veldhuisen, R., et al. (2025). Rare species do not disproportionately contribute to phylogenetic diversity in a subalpine plant community. American Journal of Botany. →
The seed-to-seedling transition constitutes a critical bottleneck in the life history of plants and represents a major determinant of species composit...
Intraspecific adaptation in Abies sachalinensis was examined using models based on long-term monitoring data gathered during a reciprocal transplant e...
Aim: Ecologically driven diversification can create spectacular diversity in both species numbers and form. However, the prediction that the match bet...
Variation in wood specific gravity (WSG) within and across species of tropical trees is poorly studied in relation to vegetation change during tropica...
Accurately monitoring tropical forest carbon stocks is an outstanding challenge. Allometric models that consider tree diameter, height and wood densit...
This repository contains three supplemental tables for Veldhuisen et al.'s paper titled "Phylogenetic patterns over sixty-five years of vegetation cha...
Light foraging by trees is a fundamental process shaping forest communities. In heterogeneous light environments this behavior is expressed as plastic...
Specialization is common in most lineages of insect herbivores, one of the most diverse groups of organisms on earth. To address how and why specializ...
Invasive plants are hypothesized to have higher fitness in introduced areas due to their release from pathogens and herbivores and the relocation of r...
We conducted a phylogenetic study of pygopodid lizards, a group of 38 species endemic to Australia and New Guinea, with two major goals:to reconstruct...
1. The capacity of urban areas to deliver provisioning ecosystem services is commonly overlooked and underutilized. Urban populations have globally in...