Weather

Assessing impacts of fire and post-fire mitigation on runoff and erosion from rangelands

View fact sheet. • Amplified runoff and erosion responses are most likely where fire increases bare ground to 50 to 60 percent and slopes exceed 15 percent. Extensive bare ground promotes accumulation of runoff and formation of high velocity concentrated flow, capable of entraining and transporting a high sediment load. • Runoff and erosion responses…

Long-term effects of tree expansion and reduction on soil climate in a semiarid ecosystem

View article. We sought to determine the effects of tree expansion, tree reduction treatments, and expansion phase at time of treatment over 12–13 yr post-treatment. Because the effects of tree reduction on vegetation can vary with the soil temperature/moisture regime, we also analyzed differences in soil climate variables between the mesic/aridic-xeric and frigid/xeric regime classifications…

Use of auto-germ to model germination timing in the sagebrush-steppe

View article. To demonstrate the capabilities of Auto-Germ, we calculated various germination indices and modeled germination timing for 11 different species, across 6 years, and 10 Artemisia-steppe sites in the Great Basin of North America to identify the planting date required for 50% or more of the simulated population to germinate in spring (1 March…

Frost dynamics of sagebrush steppe soils

View article. Recent research has indicated that seeds may germinate too soon after fall sowing and seedlings suffer high mortality from frost during the winter. To help determine the length of germination delay needed to avoid seedling frost mortality and to help guide frost‐tolerance experiments, we analyzed fall to spring soil temperatures from 2010 to…

Unusual behavior in parental care by a house wren (Troglodytes aedon): Post fledging use of an old nest during cold nights

View article. I report on the unusual behavior of an adult house wren (Troglodytes aedon) leading recently fledged young back to the nest for two consecutive nights. The ambient temperature reached below 0 °C during both nights. Despite disadvantages associated with remaining in the nest, this observation suggests that adult birds may assess trade-offs between…

Using germination prediction to inform seeding potential: I. Temperature range validation of germination prediction models for the Great Basin, USA

View article. Wet thermal germination regression models predict when subpopulations of seeds will germinate based on the summation of thermal time when seedbed soil water potential > −1.5 MPa. Germination rates fit models well at temperatures greater than 5 °C and less than 25 °C, but may not fit as well outside of that range.…

Can wildfire serve as an ecohydrologic threshold-reversal mechanism on juniper-encroached shrublands?

View article. Our findings suggest that the biotic-to-abiotic shift and amplified cross-scale erosion occur where encroachment-induced bare ground exceeds 50–60% and bare gaps between plant bases frequently extend beyond 1 m. The trigger for amplified cross-scale erosion is formation of concentrated flow within the degraded intercanopy between trees. Burning in this study decreased ecohydrologic resilience of…

Episodic occurrence of favorable weather constrains recovery of a cold desert shrubland after fire

View article. We collected A. tridentata stem samples from 33 plots in 12 prescribed fire sites that burned 8–11 years before sampling. We determined individual establishment years using annual growth rings. We measured seasonal soil environmental conditions at the study sites and asked if these conditions predicted annual establishment density. We then evaluated whether establishment…

Using predictive modeling tools to improve timing of seeding treatments

Researchers at BYU used SageSTEP soil moisture and temperature data to develop a tool that predicts germination in the sagebrush steppe and shows how some species are more likely to experience premature germination when sown in the fall – a step toward better rangeland seeding practices. Matt Madsen knows that getting seeds to grow in…

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