Filters: Tags: freezing (X)76 results (111ms)
Response of shoal grass, Halodule wrightii, to extreme winter conditions in the Lower Laguna Madre, Texas
Yosemite Toad (Anaxyrus canorus) project datasets; climate, disease, predation, and hatching success data
These data are associated with an article published in Global Ecology and Conservation (https://doi.org/10.1016/j.gecco.2020.e01173) that describes climate's cascading effects on disease, predation, and hatching sucess in the Yosemite toad (Anaxyrus canorus). The Yosemite toad currently is federally listed as threatened under the U.S. Endanered Species Act based upon reported population declines and vulnerability to climate and other global-change factors. The species occurs only in California’s central Sierra Nevada at medium to sub-alpine elevations. Lands throughout its range largely are protected from development, but climate and other global-change factors potentially can limit populations.
Drought and freezing are both known to limit desert plant distributions, but the interaction of these stressors is poorly understood. Drought may increase freezing tolerance in leaves while decreasing it in the xylem, potentially creating a mismatch between water supply and demand. To test this hypothesis, we subjected Larrea tridentata juveniles grown in a greenhouse under well-watered or drought conditions to minimum temperatures ranging from -8 to -24 �C. We measured survival, leaf retention, gas exchange, cell death, freezing point depression and leaf-specific xylem hydraulic conductance (k?). Drought-exposed plants exhibited smaller decreases in gas exchange after exposure to -8 �C compared to well-watered...
Plant-microbe competition for soil amino acids in the alpine tundra: effects of freeze-thaw and dry-rewet events
Amino acids have been shown to be a potentially significant N source for the alpine sedge, Kobresia myosuroides. We hypothesised that freeze-thaw and dry-rewet events allow this plant species increased access to amino acids by disrupting microbial cells, which decreases the size of competing microbial populations, but increases soil amino acid concentrations. To test this hypothesis, we characterized freeze-thaw and dry-rewet events in the field and simulated them in laboratory experiments on plant-soil microcosms. In one experiment, 15N,13C--glycine was added to microcosms that had previously been subjected to a freeze-thaw or dry-rewet event, and isotopic concentrations in the plant and microbial fractions...