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Influence of Climate on Annual Production of Seven Cold Desert Forage Species
Stepwise regression analyses were used to examine the relationships between annual production of seven cold desert forage species and climate variables at different periods of the year. No significant regressions were found for production of Artemisia arbuscula var. nova, Oryzopsis hymenoides, or Sitanion hystrix with precipitation and temperature. For Artemisia tridentata, Atriplex confertifolia, Ceratoides lanata, and Atriples gardeneri, significant (p<.05) regressions were found between annual production and precipitation during the spring months. For Artemisia tridentata and Atriplex confertifolia, mean monthly temperature in March and April also appeared in the equations. Multiple regression was used to test the null hypothesis that the amount of variation in annual production explained by winter (November-February) or spring (March-June) precipitation was equal to zero. No significant (p<.05) linear relationship was found between winter precipitation and production, whereas such a relationship appeared more likely for spring precipitation and production of Artemixia tridentata, Ceratoides lanata, and Atriplex gardeneri.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment
As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced
Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.Peer reviewe
Response of dark respiration to temperature in Eriophorum vaginatum from a 30-year-old transplant experiment in Alaska
Background: In the Arctic region, temperature increases are expected to be greater under anticipated climate change than the global average. Understanding how dark respiration (
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