Filters: Tags: Cold hardiness (X)10 results (107ms)
Cold-induced mortality is a key factor driving mountain pine beetle( Dendroctonus ponderosae) population dynamics. In this species, the supercooling point (SCP) is representative of mortality induced by acute cold exposure. Mountain pine beetle SCP and associated cold-induced mortality fluctuate throughout a generation, with the highest SCPs prior to and following winter. Using observed SCPs of field-collected D. ponderosae larvae throughout the developmental season and associated phloem temperatures, we developed a mechanistic model that describes the SCP distribution of a population as a function of daily changes in the temperature-dependent processes leading to gain and loss of cold tolerance. It is based on...
Assimilation and stomatal conductance responses of red spruce to midwinter frosts and the constituent ions of acid mist
To investigate the evolution of clinal variation in an invasive plant, we compared cold hardiness in the introduced saltcedar (Tamarix ramosissima, Tamarix chinensis, and hybrids) and the native plains cottonwood (Populus deltoides subsp. monilifera). In a shadehouse in Colorado (41Â°N), we grew plants collected along a latitudinal gradient in the central United States (29â€“48Â°N). On 17 occasions between September 2005 and June 2006, we determined killing temperatures using freeze-induced electrolyte leakage and direct observation. In midwinter, cottonwood survived cooling to âˆ’70Â°C, while saltcedar was killed at âˆ’33 to âˆ’47Â°C. Frost sensitivity, therefore, may limit northward expansion of saltcedar in North...
Seasonal variation in the frost hardiness of Scots pine and Norway spruce in old provenance experiments in Finland
Survival of Imported Fire Ant (Hymenoptera: Formicidae) Species Subjected to Freezing and Near-Freezing Temperatures
Intense natural selection on body size and wing and tail asymmetry in cliff swallows during severe weather