The Effects of Climate Change on the Phenological Interactions of Plants and Pollinators

Symposium title: Interdisciplinary Canary: Linkages between Ecology and Sustainable Decision Making in a Dynamic Environment

*1) Background/Question/Methods*
The responses of pollinators to climate change could include changes in phenology of migratory pollinators and in the routes or destinations for their migration, changes in the phenology and distribution of non-migratory species, and changes in the host plants they visit for nectar and pollen. Plants face similar challenges with regard to changes in their distributions, their reproductive phenology, and interactions with both co-flowering species and pollinators (competition, facilitation, etc.). Unless pollinators and their host plants are responding similarly to changing environmental cues that affect their phenology, their historical patterns of interaction, both mutualistic and competitive, are likely to change. Long-term data are essential to investigating which if any of these potential outcomes are occurring. A 36-year record of abundance and phenology of flowering of 90+ wildflower species, surveys of the altitudinal distribution of bumble bees in the 1970s and the past few years, and data from a long-term Malaise trap sampling program, all near the Rocky Mountain Biological Laboratory (West Elk mountains, Colorado) are used for this investigation. 

*2) Results/Conclusions*
Although the flowering phenology of all species examined to date is affected by a single environmental event, disappearance of the winter snowpack (range 22 April -19 June since 1975), either their responses to that single cue are not uniform, or different species respond to additional cues in addition to snowmelt (e.g., growing degree days). Thus the community of co-flowering species varies temporally and quantitatively among years; differential sensitivity to frost damage is an example of an environmental variable that generates the quantitative variation among years, and is in turn affected by date of snowmelt. Arrival dates of migratory Broad-tailed Hummingbirds are significantly correlated with the amount of snow remaining on 30 April, and with the day of first flowering of Erythronium grandiflorum (glacier lily), the first flower that they visit at this site in the spring. Altitudinal distributions of at least some bumble bee species, and of the flowers they feed on, are also changing, with one bee species occurring about 600m higher than it did 30 years ago and one wildflower (Mertensia cilata) disappearing from lower altitudes where it was historically common. As these communities of plants and pollinators respond to environmental changes with changes in phenology and distribution, new interactions will be created and old ones will be lost

Auroral rocket experiment 2 Final report

Detecting fluxes of energetic neutral hydrogen atoms in interplanetary medium by auroral rocket flight

Localized Asymmetric Atomic Matter Waves in Two-Component Bose-Einstein Condensates Coupled with Two Photon Microwave Field

We investigate localized atomic matter waves in two-component Bose-Einstein condensates coupled by the two photon microwave field. Interestingly, the oscillations of localized atomic matter waves will gradually decay and finally become non-oscillating behavior even if existing coupling field. In particular, atom numbers occupied in two different hyperfine spin states will appear asymmetric occupations after some time evolution.Comment: 4 pages, 4 figure

Study of an auroral zone rocket experiment Final report

Measurement of flux and energy spectra of protons, energetic particles, hydrogen atoms, and electrons in auroral zone by Nike-Tomahawk sounding rocke

Granivory in a desert ecosystem: experimental evidence for indirect facilitation of ants by rodents

Journal ArticleTwo major groups of desert granivores, ants and rodents, coexist as permanent residents of local desert habitats in southwestern North America. At our Sonoran Desert study site, both of the major taxa exhibited short-term increase in density when the other taxon was experimentally removed. Over the longer term, density compensation continued at a relatively constant level for rodents in the absence of ants. In contrast, beginning about 2 years after initiation of experiments, ant populations on rodent removal plots showed a gradual but significant decline relative to densities on control plots. Indirect interactions, mediated through ant and rodent resources, may account for these differences. Removal of harvester ants leads to higher annual plant densities only in small-seeded species. These plants are relatively poor competitors and do not displace the large-seeded annuals, on whose seeds rodents specialize. In contrast, rodent removal leads to a differential increase in large-seeded annuals, which competitively displace the small-seeded resource species of ants. The decline of ant populations on rodent removal plots preceded by several years the first detectable evidence for competitive suppression of small-seeded annuals. Because ants do not excavate buried seed, they probably experienced resource depression before buried seed reserves were exhausted through germination and subsequent competitive inhibition

Direct evaporative cooling of 41K into a Bose-Einstein condensate

We have investigated the collisional properties of 41K atoms at ultracold temperature. To show the possibility to use 41K as a coolant, a Bose-Einstein condensate of 41K atoms in the stretched state (F=2, m_F=2) was created for the first time by direct evaporation in a magnetic trap. An upper bound of three body loss coefficient for atoms in the condensate was determined to be 4(2) 10^{-29} cm -6 s-1. A Feshbach resonance in the F=1, m_F=-1 state was observed at 51.42(5) G, which is in good agreement with theoretical prediction.Comment: 4 pages, 4 figure