Long-Term Dynamics of Production, Respiration, and Net CO2 Exchange in Two Sagebrush-Steppe Ecosystems

We present a synthesis of long-term measurements of CO2 exchange in 2 US Intermountain West sagebrush-steppe ecosystems. The locations near Burns, Oregon (1995-2001), and Dubois, Idaho (1996-2001), are part of the AgriFlux Network of the Agricultural Research Service, United States Department of Agriculture. Measurements of net ecosystem CO2 exchange (Fc) during the growing season were continuously recorded at flux towers using the Bowen ratio-energy balance technique. Data were partitioned into gross primary productivity (Pg) and ecosystem respiration (Re) using the light-response function method. Wintertime fluxes were measured during 1999/2000 and 2000/2001 and used to model fluxes in other winters. Comparison of daytime respiration derived from light-response analysis with nighttime tower measurements showed close correlation, with daytime respiration being on the average higher than nighttime respiration. Maxima of Pg and Re at Burns were both 20 g CO2 m2 d-1 in 1998. Maxima of Pg and Re at Dubois were 37 and 35 g CO2 m-2 d-1, respectively, in 1997. Mean annual gross primary production at Burns was 1 111 (range 475-1 715) g CO2 m-2 y-1 or about 30% lower than that at Dubois (1 602, range 963-2 162 g CO2 m-2 y-1). Across the years, both ecosystems were net sinks for atmospheric CO2 with a mean net ecosystem CO2 exchange of 82 g CO2 m-2 y-1 at Burns and 253 g CO-2 m-2 y-1 at Dubois, but on a yearly basis either site could be a C sink or source, mostly depending on precipitation timing and amount. Total annual precipitation is not a good predictor of carbon sequestration across sites. Our results suggest that Fc should be partitioned into Pg and Re components to allow prediction of seasonal and yearly dynamics of CO2 fluxes. The Rangeland Ecology & 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 2020Legacy DOIs that must be preserved: 10.2458/azu_jrm_v59i6_gilmano

A Knowledge-Based Intervention for Promoting Carpooling

The use of interesting text, particularly stories, has been shown to be an effective way of transferring information. This is due, in part, to the compatibility of narrative forms of information with human information processing biases. This study tested the impact of a story-based intervention on employees' knowledge and attitudes about, and stated willingness to adopt, carpooling. The story-based intervention was compared to a fact sheet-based intervention and to a control. A total of 645 employees at five sites participated in the study. Results indicate that individuals who received information, whether in story or factual format, felt more comfortable with their carpool knowledge and felt that they had adequate knowledge to guide them in discussions and problem solving regarding carpooling. Furthermore, regardless of the type of intervention, the more interesting text was associated with greater perceived knowledge, greater confidence and comfort with knowledge, and increased willingness to try carpooling. The interventions had no significant impact on attitudes. Implications and suggestions for future research are offered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67204/2/10.1177_0013916595275003.pd

Some conceptual difficulties in the theory of social conflict

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67560/2/10.1177_002200276801200402.pd