Natural Resource Ecology Laboratory (NREL)
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These digital collections include faculty publications, presentations, reports, and datasets from the Natural Resource Ecology Laboratory (NREL). Included here are individual datasets for the Ethiopia Project, Shortgrass Steppe-Long Term Ecological Research (SGS-LTER), Riparian Habitat and Invasive Species in the Colorado River Basin, and Yellowstone Willows LTREB. Also included is a collection of publications by Eldor A. Paul, a Senior Research Scientist at the Natural Resource Ecology Laboratory and a Professor in the Department of Soil and Crop Sciences.
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Item Open Access 14C Allocation in tree–soil systems(Colorado State University. Libraries, 1994) Paul, Eldor A., author; Pregitzer, Kurt S., author; Horwath, William R., author; Heron Publishing, publisherWe studied whole-tree C allocation with special emphasis on the quantification of C allocation to roots and root respiration. To document seasonal patterns of C allocation, 2-year-old hybrid poplar trees greater than 3 m tall were labeled with 14CO2 in a large Plexiglas chamber in the field, in July and September. Climate and CO2 concentration were controlled to track ambient conditions during labeling. Individual tree canopy CO2 assimilation averaged 3.8 μmol CO2 m−2 s−1 (12.9 g C day−1 tree−1) in July and 6.2 μmol CO2 m−2 s−1 (9.8 g C day−1 tree−1) in September. Aboveground dark respiration was 12% of net daytime C fixation in July and 15% in September. Specific activity of root–soil respiration peaked 2 days after labeling and stabilized to less than 5% of maximum 2 weeks later. Low specific activity of root–soil respiration and a labeled pool of root C demonstrated that current photosynthate was the primary source of C for root growth and maintenance during the growing season. Root respiration averaged 20% of total soil respiration in both July and September based on the proportion of labeled C respired to labeled C fixed. In July, 80% of the recovered 14C was found above ground and closely resembled the weight distribution of the growing shoot. By September, 51% of the recovered 14C was in the root system and closely resembled the weight distribution of different size classes of roots. The finding that the distribution of biomass and 14C were similar verified that the C introduced during labeling followed normal seasonal translocation pathways. Results are compared to smaller scale labeling studies and the suitability of the approach for studying long-term C fluxes is discussed.Item Open Access 1970 insect studies at Osage comprehensive site(Colorado State University. Libraries, 1971) Blocker, H. Derrick (Henry Derrick), 1932-, author; Reed, Rodman Clay, 1947-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access 1970 meteorological data availability for the Pawnee site(Colorado State University. Libraries, 1971) Nunn, John R. (John Robert), 1944-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access 1970-1971 soil movement at the Pawnee intensive site(Colorado State University. Libraries, 1972) Alldredge, A. William, author; Whicker, F. Ward., 1937-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access 1987-1991 final report(Colorado State University. Libraries, 1987-1991) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorThe Central Plains Experimental Range (CPER) Long Term Ecological Research (LTER) project focused on spatial and temporal patterns of ecosystem structure and function at the CPER in northcentral Colorado. Research was concentrated in 5 areas: soil water; primary production; population dynamics; organic matter accumulation and nutrient dynamics; and disturbances. We produced exciting results in each of these 5 areas and significantly changed the state of knowledge about the origin and sustainability of shortgrass steppe ecosystems.Item Open Access 1991 annual report(Colorado State University. Libraries, 1991) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorThis progress report is for the period February 1990 - July 1991 for the Central Plains Experimental Range long term ecological research project at Colorado State University. Our previous report was included with our 1990 renewal proposal.Item Open Access 1991 CPER pasture treatment map(Colorado State University. Libraries, 1991) Central Plains Experimental Range, mapmakerSections include: holding, winter, steer, nitrogen/atrazine 1976-90, 1991 steers, stocker heifers, 2 year olds, GI reserve, grazing intensity, and bulls.Item Open Access 1992 annual report(Colorado State University. Libraries, 1992) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorThe Central Plains Experimental Range Shortgrass Steppe long term ecological research project (BSR-9011659 LTER) had a successful year in 1991-92. We have continued to collect data regarding long term patterns in ecosystem structure and function, while initiating important new studies to further our understanding of the shortgrass steppe. The project produced 20 papers in refereed journals during the last 2 years (1990 and 1991). We supported a large number of graduate, undergraduate, and high school students for research at the site. Scientists from our project are involved in LTER network activities, through comparative modeling studies, database management, and development of new cross-site experiments. We provide a summary of the new activities and products from our site during 1991-1992, and our plans for 1992-93. A more detailed description of our scientific activities, organized by core area is included.Item Open Access 1992 CPER pasture treatment map(Colorado State University. Libraries, 1992) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, bulls, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.Item Open Access 1993 annual report(Colorado State University. Libraries, 1993) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorThe Central Plains Experimental Range long term ecological research project was first funded in 1982. In the past 11 years, the project has supported a large number of studies. Since nearly all of these studies are long-term in nature, it is appropriate to summarize not only new activities, but also the continuing projects within the research program. We have organized our report into 5 key areas: Core Area Research, Synthesis Activities, Current International Collaborations, Interactions with other Projects, and Data Management.Item Open Access 1993 CPER pasture treatment map(Colorado State University. Libraries, 1993) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, safety trial study, steers, stocker heifers, yearling breeders, and winter pastures.Item Open Access 1994 annual report(Colorado State University. Libraries, 1994) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorThis is the 1993-94 progress report for the project entitled "Long term ecological research program - Shortgrass Steppe" (BSR 9011659) funded to Colorado State. University. We had a successful year, and continue to make very good progress in furthering our understanding of the shortgrass steppe. The project produced 25 total papers and 15 papers in refereed journals since our last report. We supported a large number of graduate, undergraduate, and post doctoral fellows for research at the site. In addition, five senior-level scientists were added to our LTER in order to expand the breadth of scientific expertise and research being conducted at the site: Drs. Mike Coughenour (ecophysiological modeling, plant-animal interactions), Bill Hunt (soil food web ecology), Diana Freckman (nematode ecology), Jeff Welker (ecophysiology), and Chuck Grier (root ecology). Scientists at our site are involved in a number of LTER network activities, through comparative modeling studies, database management, international collaborations, and development of new cross-site experiments. The report contains two sections: Summary and Overview, and a Detailed Report. We organized both sections into four key areas: Core Area Research, Synthesis Activities, Current International Collaborations, Data Management. A List of Publications is contained at the end of the Detailed Report.Item Open Access 1994 CPER pasture treatment map(Colorado State University. Libraries, 1994) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, study steers, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.Item Open Access 1995 CPER pasture treatment map(Colorado State University. Libraries, 1995) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, study steers, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.Item Open Access 1996 annual report(Colorado State University. Libraries, 1996) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorItem Open Access 1996 CPER pasture treatment map(Colorado State University. Libraries, 1996) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, study steers, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.Item Open Access 1997 annual report(Colorado State University. Libraries, 1997) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorItem Open Access 1997 CPER pasture treatment map(Colorado State University. Libraries, 1997) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, study steers, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.Item Open Access 1998 annual report(Colorado State University. Libraries, 1998) Shortgrass Steppe Long Term Ecological Research (SGS-LTER), authorItem Open Access 1998 CPER pasture treatment map(Colorado State University. Libraries, 1998) Central Plains Experimental Range, mapmakerSections include: privately owned and operated, two year old heifers, study steers, stocker steers, stocker heifers, yearling breeders, replacement heifers, and winter pastures.