Translating bumblebee dialect…
Examines how plant community composition, species richness, and floral diversity shift across elevation gradients, successional timescales, and environmental disturbances in Rocky Mountain meadows and subalpine zones, with some connection to vegetation assessment near the Mount Emmons mine.
Alpine and subalpine plant communities in the Gunnison Basin are among the most botanically diverse ecosystems in the southern Rocky Mountains. The valley around the Rocky Mountain Biological Laboratory (RMBL) in Gothic, Colorado spans roughly 8,000 to 14,000 feet in elevation, packing dramatic gradients of temperature, snowmelt timing, and precipitation into a small geographic area (Alvarado, 2019). These gradients shape the identity and relative abundance of species that grow together — what ecologists call community composition. Understanding which species occur where, how often they appear (their frequency), and how those patterns change through time is essential for predicting how mountain meadows will respond to a warming climate, shifting snowpack, invasive species, and herbivory.
Several concepts recur throughout the research that follows. Phylogenetic distance refers to how evolutionarily related two species are; close relatives may share traits that make them compete for the same pollinators, while distant relatives may coexist more easily. Herbivore preference describes the selective feeding choices of animals like deer, marmots, and grasshoppers, which can reshape plant communities by suppressing palatable species and releasing others. Ecological restoration — and its hands-on tool, transplanting native plants into disturbed soils — is increasingly important in this landscape, where old mining scars, road cuts, and earthflows interrupt otherwise intact meadows. Finally, sampling effort matters: the more carefully and broadly researchers survey a meadow, the more species they tend to find, which has important consequences for interpreting historical records against modern surveys.
These ideas combine in a research tradition that treats RMBL's meadows as a natural laboratory. Long-term plots, herbarium records dating to 1929, and repeated surveys allow scientists to ask not only what lives here, but how the community is changing — and why.
Early studies at RMBL established the basic energetic and successional baselines for this work. Andersen and Armitage (Andersen & Armitage, 1976) measured the caloric and ash content of Rocky Mountain subalpine and alpine herbaceous plants, providing reference values for how much energy these plants offer the herbivores that eat them. Turbak (Turbak, 1969) began documenting plant succession on the Gothic earthflow, a disturbed slope that has since become one of the longest-running successional study sites in the region; follow-up work showed that species diversity on the earthflow peaked around 1970 and stabilized as pioneer species gave way to perennial forbs .
The identity and relative abundance of species within an ecological community
Selective feeding behavior of herbivores that favors certain plant traits or genotypes over others
Evolutionary divergence time between species measured in millions of years, calculated from molecular phylogenetic reconstructions
The process of managing or assisting the recovery of an ecosystem that has been degraded, damaged or destroyed as a means of sustaining ecosystem resi...
Moving native plants from one location to establish them in a disturbed site as a revegetation technique
Calculation of multiple phylogenetic diversity metrics for plant communities using established phylogenetic trees and null model approaches to test fo...
Nested sampling design to construct species-area relationships across multiple spatial scales by subdividing plots into equal-area quadrats and averag...
Pressing and identification of plant voucher specimens using standard botanical keys and herbarium references.
Systematic collection and GPS mapping of predator scats along established trail networks to quantify spatial patterns of predator activity relative to...
Systematic collection and spectrophotometric analysis of flowers across elevation gradients to quantify color variation. Targets pollinator-visible fl...
Conversion of reflectance spectra into bee and bird visual spaces using established photoreceptor sensitivity models. Uses color hexagon model for bee...
Environmental assessment (1978). Covers Mount Emmons, Alkali Basin, Antelope Creek Basin. Topics: vegetation studies, wildlife studies, herb layer sum...
YEAR/AGE {SUBDIVISION NAME TYPE TOTAL |LOTS UNITS [LOTS [MAX [MIN PROBABLE |BUILDOUT LOTS DEVELOPED/BUILT |VACANT|UNITS [UNITS |UNITS RATE/YEAR CRESTE...
Later landmark studies broadened the focus from energetics and succession to interactions. Burkle and Irwin (Burkle & Irwin, 2009) demonstrated that subalpine plant–pollinator networks were surprisingly robust to nitrogen enrichment but varied dramatically from year to year due to species turnover. Sloat and colleagues (Sloat et al., 2014) revived Darwin's hypothesis that species with broader ecological ranges show greater trait variation, finding that wide-ranging plants at RMBL had more variable leaf traits along the elevation gradient. Together these papers framed the questions that still drive the field: how do trait variation, species interactions, and environmental change combine to structure mountain plant communities?
A central thread in the research is that elevation organizes plant communities in surprising ways. Contrary to the textbook expectation that diversity falls with altitude, several RMBL surveys have found that species richness increases with elevation across the Gunnison Basin, with rainfall an even stronger predictor than elevation itself (Miller, 2009). Geographic distance between sites was the single best predictor of community differences (Miller, 2009). Within species, plants adjust their leaf traits along the gradient: nine of twelve species studied showed significant changes in specific leaf area with elevation, and these intraspecific shifts moved in the same direction as community-wide changes, though at smaller magnitude (Sloat et al., 2014). Floral color also reorganizes with elevation, with violet and blue species declining and yellow, orange, and red species becoming more common at higher sites (The Changing Floral Color Landscape Across an Alpine Elevation Gradient, 2016).
Species interactions emerge as equally powerful drivers of community composition. The hemiparasitic genus Castilleja, which taps into the roots of neighboring plants, consistently increases local species richness and diversity by suppressing dominant hosts; removal experiments showed evenness dropped by up to 34% when Castilleja was taken out (The effects of hemiparasitism by Castilleja spp., 2011), and more recent work confirmed Castilleja parasitizes 21 host taxa across 11 families, with grasses most frequently targeted (Hastings, 2024). Herbivory operates from the top down as well: Waser and colleagues (Waser et al., 2014) traced a trophic cascade in which coyotes avoid the area near the RMBL field station, deer concentrate there, and palatable wildflowers suffer reduced seed production and seedling recruitment as a result. Yellow-bellied marmots also act as selective foragers, rejecting alkaloid-containing plants (Observations on plant choice by foraging yellow-bellied marmots, 2003).
Plant–pollinator interactions add another layer of structure. Phylogenetic neighborhood influences who gets visited: species with many moderately related neighbors receive more visits, while extremely close relatives appear to compete for pollinator attention (Evans Peck, 2012). Pollinator preferences are also visually mediated — birds perceive more color variation in bird-pollinated flowers than bees perceive in bee-pollinated ones (Whitney et al., 2020). And although networks are stable in their overall architecture under nitrogen enrichment, they reshuffle substantially from year to year (Burkle & Irwin, 2009).
Research since 2020 has shifted decisively toward climate change and biological invasions. Mt. Baldy surveys document flowering phenology now occurring two to three weeks earlier than a decade ago, with both snowmelt timing and the spatial clustering of plants shaping when species bloom (Xu, 2025). Experimental manipulations of snowmelt, warming, and dominant-species removal show species-specific responses in plant height and leaf traits, suggesting that no single rule will predict how communities reassemble (Piedra, 2023). Phenological mismatches between plants and pollinators are an active area: accelerated snowmelt has been shown to broaden pollinators' diets, with late-blooming species gaining new visitors while early species' partnerships stay relatively stable (Sharer, 2019).
Invasive species and herbivore–climate interactions are also drawing new attention. Eight years of nitrogen manipulation showed that the invasive Linaria vulgaris responds positively to added nitrogen, while overall species richness declined across all treatments, raising concerns about long-term meadow diversity (Wen, 2024). Tests of whether dandelions compete with natives for pollinators yielded mixed results, with some natives outcompeting them and others losing out (Salazar, 2023). Soil moisture and warming experiments demonstrate that climate stress alters leaf palatability and shifts herbivore preferences among species (Pittman, 2021), while warming-driven changes in floral resources are reshaping foraging patterns of broad-tailed hummingbirds (Ngo, 2025).
Many large questions remain. How will the interactions among warming, earlier snowmelt, invasive plants, and shifting herbivore behavior combine over the coming decades — and can we predict tipping points before they occur? Restoration work has identified species like Erigeron speciosus and Fragaria virginiana as reliable transplants (Revegetation after disturbance in high-altitude meadow ecosystems, 2006), but it remains unclear whether revegetation can keep pace with the rate of disturbance and climate change. Belowground interactions, particularly the host networks of hemiparasites like Castilleja, are still poorly mapped. And the historical baseline itself is uncertain: herbarium records favor rare species and miss common ones, complicating comparisons between past and present (Alvarado, 2019). Resolving these gaps will require sustained long-term monitoring, integration of archival and modern records, and experiments that combine multiple global-change drivers at once.
Alvarado (2019). Surveying historical patterns in vegetation change (1929-2019) in the upper East River Valley using RMBL's archival herbarium records. →
Andersen, D. C., Armitage, K. B. (1976). Caloric content of Rocky Mountain subalpine and alpine plants. Journal of Range Management. →
Burkle, L., Irwin, R. (2009). The importance of interannual variation and bottom-up nitrogen enrichment for plant-pollinator networks. Oikos. →
Evans Peck (2012). Phylogenetic distance as a predictor of floral visitation in the plant communities of Gothic, CO. →
Hastings (2024). Getting to the Root of It: Effects of Castilleja Root Hemiparasitism on Plant Community Structure and Function. →
Miller (2009). Possible influence of altitude, geographical distance between sites and annual precipitation rates on species richness. →
Ngo (2025). Picky eater? How different environmental factors affect broad-tailed hummingbirds' foraging patterns in the Rocky Mountains. →
Observations on plant choice by foraging yellow-bellied marmots (2003). →
Piedra (2023). Effects of warming, dominant species removal, and accelerated snowmelt on aboveground plant traits in the Colorado Rocky Mountains. →
Pittman (2021). Effects of soil moisture and temperature on plant palatability and herbivore plant preference. →
Plant Successional Changes Over 67 Years on the Gothic Earthflow (2014). →
Revegetation after disturbance in high-altitude meadow ecosystems (2006). →
Salazar (2023). Do dandelions compete with native plants for pollinator visits? →
Sharer (2019). Niche breadth changes in response to environmental perturbation: the impact of early snowmelt on subalpine plant-pollinator specialization. →
Sloat et al. (2014). Revisiting Darwin's hypothesis: Does greater intraspecific variability increase species' ecological breadth? American Journal of Botany. →
The Changing Floral Color Landscape Across an Alpine Elevation Gradient (2016). →
The effects of hemiparasitism by Castilleja spp. on community structure in alpine ecosystems (2011). →
Turbak (1969). A study of plant succession on the Gothic earthflow. →
Waser et al. (2014). Coyotes, deer, and wildflowers: diverse evidence points to a trophic cascade. Naturwissenschaften. →
Wen (2024). Effect of Nitrogen on Linaria vulgaris and Native Species. →
Whitney et al. (2020). Birds Perceive More Intraspecific Color Variation in Bird-Pollinated Than Bee-Pollinated Flowers. Frontiers in Plant Science. →
Xu (2025). Alpine plants of Mt. Baldy: modeling phenology and documenting biodiversity. →
Complete census of all individual plants in gridded plots with spatial mapping, tissue sampling, and photosynthetic area measurement for metabolic rat...