Cold, water-saturated soils play important biogeochemical roles, yet almost nothing is known about the identity and habitat of microbes active under such conditions. We investigated the year-round microenvironment of an alpine tundra wet meadow soil in the Colorado Rocky Mountains, focusing on the biogeochemistry and microbial diversity of spring snowmelt--a dynamic time for alpine ecosystems. ...

In deciduous trees, measurement of stem water potential can be difficult during the leafless period in winter. By using thermocouple psychrometry, osmotic water potentials (Ψo; actual Ψo: Ψo(act); Ψo at full saturation: Ψo(sat)) of expressed sap of bark and bud tissue were measured in order to test if the severity of winter desiccation in apple stems could be sufficiently assessed with Ψo. Wate...

As ground nesting homeotherms, alpine and arctic birds must meet similar physiological requirements for breeding as other birds, but must do so in more extreme conditions. Annual spring snowfall and timing of snow melt can vary by up to 1 month and daily temperatures near the ground surface vary from below freezing to over 45°C in alpine and arctic habitats. Species breeding in these environmen...

The microbial process of methane (CH4) production during the back-freezing of permafrost soils in autumn and the future fate of produced CH4 in the thawing phase of the following spring are not well understood. Long-term CH4 flux studies in the Lena Delta (Siberia) indicate that back-stored CH4 adds to the emission of newly-produced CH4 at the beginning of the vegetation period. Further field a...

Related Articles Testing recent charge-on-spring type polarizable water models. I. Melting temperature and ice properties J. Chem. Phys. 137, 194102 (2012) Freezing singularities in water drops Phys. Fluids 24, 091102 (2012) Impact response and dynamic strength of partially melted aluminum alloy J. Appl. Phys. 112, 053511 (2012) Study of strain fields caused by crystallization of boron doped am...

Related Articles Testing recent charge-on-spring type polarizable water models. I. Melting temperature and ice properties J. Chem. Phys. 137, 194102 (2012) Freezing singularities in water drops Phys. Fluids 24, 091102 (2012) Impact response and dynamic strength of partially melted aluminum alloy J. Appl. Phys. 112, 053511 (2012) Study of strain fields caused by crystallization of boron doped am...

The effects of temperature on pollen germination and pollen tube growth rate were measured in vitro in thermogenic skunk cabbage, Symplocarpus renifolius Schott ex Tzvelev, and related to floral temperatures in the field. This species has physiologically thermoregulatory spadices that maintain temperatures near 23 degrees C, even in sub-freezing air. Tests at 8, 13, 18, 23, 28 and 33 degrees C ...

Understanding cold acclimation and identifying the low molecular weight carbohydrates that support the development of freezing tolerant safflower seedlings will aid in breeding winter-hardy cultivars for temperate cropping systems. Three field selected lines of winter safflower (WSRC01: PI 651878; WSRC02: PI 651879; WSRC03: PI 651880) were cold acclimated for four weeks at 4 °C and compared to ...