We used overhead infrared radiators to add a constant increment of °15 W/m2, over 2 yr, to the downward heat flux on five 30‐m2 montane meadow plots in Gunnison County, Colorado, USA. Heating advanced snowmelt by °1 wk, increased summer soil temperatures by up to 3°C, and reduced summer soil moistur

Little advantage was taken of what was possibly the greatest opportunity in modern times to observe the recolonization of an island, when much of the island was blown into the air and the remainder was covered by many feet of glowing volcanic ash.

Evidence is presented for plants, and by extension for animals as well, that high ploidy levels alone could (independent of breeding system) endow individuals with the ability to tolerate these ‘extreme’ environments.

While direct plant responses to global change have been well characterized, indirect plant responses to global change, via altered species interactions, have received less attention. Here, we examined how plants associated with four classes of fungal symbionts (class I leaf endophytes [EF], arbuscul

Results from simulations suggest that competition for pollination through interspecific pollen transfer can result in rapid exclusion of one of two species, and that such competition represents a selective force promoting stable divergence of potential competitors in habitat affinity, flowering time

Evaluated treeline ecotones in seven temperate regions of the world find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground-

I measured phenotypic selection of floral traits through both male and female functions of the hermaphroditic flowers of Ipomopsis aggregata (Pursh) V. Grant subsp. aggregata (Polemoniaceae). Fluorescent powdered dyes were used to track movement of pollen by hummingbirds and to measure pollen delive

A picture is provided of the intra-specific response of a suite of traits to ecological stress in the butterfly Speyeria mormonia, whereby fecundity is affected by adult dietary restriction, a pattern reminiscent of a survival/reproduction trade-off, but across a developmental boundary.

It is argued that ACSs are “predictably ephemeral” habitats that present a selective environment that is different from that commonly envisioned for disturbed or early successional habitats, and therefore, effective biological control strategies in ACSs must include a landscape ethic that provides a

(1) The transport of pollen from donor flowers by bumble bees was measured by examining deposition on stigmata of sequences of recipient flowers. The rate of decay of grain deposition was estimated as a measure of pollen carryover. (2) Bombus bifarius was a much less effective pollinator of Erythron

We quantified pollinator visit behavior, pollen receipt and export, and changes in allele and genotype frequencies from initial Hardy‐ Weinberg conditions in experimental arrays of two color morphs of snapdragons (Antirrhinum majus) visited by freely foraging bumble bees (Bombus appositus and B. fla

The social substructure and the distribution of genetic variation among colonies of yellow-bellied marmots, when analyzed as an evolutionary system, suggests that this substructure enhances the intercolony variance and retards the fixation of genetic variation. This result supports a traditional the

We present four lines of evidence that the magnitude of prey exchange (=immigration/emigration) among substrate patches has an overwhelming influence on the perceived effects of predators on prey populations. (1) An extensive review of the literature on predation effects in benthic and littoral fres

Soils contain more carbon than plants or the atmosphere, and sensitivities of soil organic carbon (SOC) stocks to changing climate and plant productivity are a major uncertainty in global carbon cycle projections. Despite a consensus that microbial degradation and mineral stabilization processes con

Increasing “greenhouse” gases are predicted to warm the earth by several degrees Celsius during the coming century. At high elevations one likely result is a longer snow-free season, which will affect plant growth and reproduction. We studied flowering and fruiting of 10 angiosperm species in a suba

SummaryIncreasing urbanization and recreational activities around and within biodiversity hotspots require an understanding of how to reduce the impacts of human disturbance on more than a single species; however, we lack a general framework to study multiple species. One approach is to expand on kn

Restricted gene flow and localized selection should establish a correlation between physical proximity and genetic similarity in many plant populations. Given this situation, fitness may decline in crosses between nearby plants (inbreeding depression), and in crosses between more widely separated pl

Predators can have consequences on prey populations and communities that extend well beyond direct predator—induced mortality. Predator—prey interactions often affect prey feeding rates, growth rates, or fecundities, thereby significantly affecting reproductive success of prey adults. Thus, investig

One possible effect of climate change is the generation of a mismatch in the seasonal timing of interacting organisms, owing to species-specific shifts in phenology. Despite concerns that plants and pollinators might be at risk of such decoupling, there have been few attempts to test this hypothesis