How the Colorado Forest Restoration Institute can help

Presented at the Can forests meet our energy needs? The future of forest biomass in Colorado conference, February 21, 2008, Colorado State University, Fort Collins, Colorado.Dr. Dan Binkley has worked on ecosystem productivity and nutrient cycling for 25 years, blending applied and basic perspectives in his research and teaching. Some of the applied perspectives have focused on sustaining the productivity of forests by sustaining soil fertility and providing useful information in textbooks and courses for people who manage forests. His basic research perspectives include long-term changes in vegetation and soils (along rivers, with tree invasion of tundra as climate warms, and in common-garden experiments), and fundamental controls on ecosystem productivity over time (using plantations of Eucalyptus species in Hawaii and Brazil as model systems). Dr. Binkley has been at Colorado State University for 20 years, teaching courses on a wide range of topics in ecology and sustainable forestry. He was the Director of CSU's cross-campus Graduate Degree Program in Ecology for 12 years, and is now the Director of the new Colorado Forest Restoration Institute. Prior to CSU, Dr. Binkley spent 5 years as an assistant professor at Duke University's School of Forestry and Environmental Studies. He holds degrees from Oregon State University (1982 PhD in forest ecology, with minors in soil science and botany), the University of British Columbia (1980 M.S. in forest ecology), and Northern Arizona University (1976 BSF in Forest Management)

Aspen Next Generation: Conversations from Southern Colorado and Northern New Mexico

Aspen trees and forests are especially important in the Rocky Mountains. Aspens add beauty to landscapes, foster high diversity and productivity of understory plants, provide for the habitat needs of many species of animals, and moderate fire behavior. There is a perception that aspen trees and stands are not regenerating well in southern Colorado and northern New Mexico; cohorts of trees younger than a few decades are scarce, at least in some areas. The next generation of aspen in the southern Rockies will be influenced by land use decisions, including harvesting, fire policy and management, and browsing by livestock and wildlife. The Aspen Next Generation (ANG) Project aimed to foster the future of aspen by pulling together insights from landowners, agency personnel, and scientists across southern Colorado and northern New Mexico. We compiled insights and concerns about the condition of aspen regeneration from a broad range of people throughout the region. The summaries of conversations include our interpretations of what we heard, and despite our best efforts to draw out the key points, our summaries won’t represent the full perspective of anyone we talked with. We hope this report will stimulate further discussion, rather than be relied on as a record of any rock-solid conclusions

Case studies of red alder and Sitka alder in Douglas-fir plantations : nitrogen fixation and ecosystem production

Seven case studies of 11 ecosystems were used to examine the effects of nitrogen-fixing alders in Douglas-fir plantations. The first case study quantified nitrogen (N) fixation and aboveground net primary production in a young Sitka alder [Alnus sinuata (Regel) Rydb.] ecosystem. At 5 yr of age, the N fixation (C₂2H₂ reduction) rate of 35 kg ha⁻¹ yr⁻¹ was near the middle of the reported range for this shrubby species. The second case study compared N fixation rates of Sitka alder and red alder (Alnus rubra Bong.) on the same sites. These species exhibited similar nodule activities and had similar nodule:leaf biomass ratios of 7-8%. A mixture of Sitka alder and Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] was estimated to have a current N fixation rate of 20 kg ha⁻¹ yr⁻¹ based on acetylene reduction; N accretion measurements indicated an average N fixation rate of 30 kg ha⁻¹ yr⁻¹ for 23 yr. A mixture of red alder and Douglas-fir on the same site had a current N fixation rate of 130 kg ha⁻¹ yr⁻¹ based on acetylene reduction, with an N accretion rate of 65 kg ha⁻¹ yr⁻¹ for 23 yr. The third case study evaluated the effects of Sitka alder on Douglas-fir growth and nutrition, and on ecosystem production and litterfall. Current Douglas-fir stem growth was 40% greater with Sitka alder, and aboveground ecosystem net primary production was increased 70% with the alder. Litterfall nutrient content was 3 to 7 times greater under the mixed canopy. The fourth and fifth case studies looked at 23 yr-old mixtures of red alder and Douglas-fir in comparison with pure Douglas-fir, on an infertile site and on a fertile site. Red alder had little effect on Douglas-fir size or growth rate on the infertile site, but ecosystem net primary production was tripled. Conversely, net primary production was not increased by red alder on the fertile site, and Douglas-fir size and growth were reduced. The final two case studies evaluated: (1) the conclusions reached in the previous case studies for applicability to red alder/Douglas-fir mixtures in general, and (2) trends in production with stand development up to age 50. These case studies were consistent with the general conclusions of site fertility interactions with red alder/Douglas-fir mixtures. With further stand development, red alder continued to enhance ecosystem production and Douglas-fir growth on infertile sites, with opposite effects on fertile sites. Sitka alder demonstrated a high potential usefulness for interplanting with Douglas-fir, and red alder greatly boosted ecosystem production on infertile sites. Both species merit further development as tools for forest management on N deficient sites

Bringing back the Kaibab deer story: A complete case study for land stewardship

The classic story of predator control, deer population explosion, and habitat degradation on the Kaibab Plateau was a cornerstone of population ecology and natural resources through the 1960s. The story has almost disappeared from natural resources, following several papers in the 1970s that questioned the quality of the evidence and the truth of the overall story. We reexamined the classic story from the viewpoint of habitat impacts of large deer populations; if the story were true, aspen regeneration should have been severely reduced in the 1920s. We also evaluated other lines of evidence, including the secondary irruption of the deer population in the 1950s

Landscape-Scale Dynamics of Aspen in Rocky Mountain National Park, Colorado

Past studies of quaking aspen in Rocky Mountain National Park suggested that the aspen population is declining due to intensive browsing by elk (Cervus elaphus). These studies were conducted in the elk winter range, an area of intensive elk impact. The elk summer range experiences less intense grazing pressure. We tested the hypothesis that impacts of elk would be greater in the elk winter range than the summer range with landscape-scale data from the Park. The detrimental effects of elk on aspen are highly localized and, at larger spatial scales, elk browsing does not seem to be influencing the aspen population

Forests and water: a state-of-the-art review for Colorado

Includes bibliographical references (pages 65-75).Forests occupy 22.6 million acres in Colorado, or 32 percent of the land area, and nearly three-quarters of the forest lands in Colorado are in public ownership. About 55 percent of the forested area is considered suitable for forest harvest. National forests comprise nearly half of the forested area and approximately 60 percent of the area is considered suitable for forest harvest. There are no significant, privately-owned, industrial forest lands in Colorado. Historic photographs, forest stand records, and other data indicate that forest density in Colorado is generally greater than in the mid to late 1800s. This increase in forest density, attributed to suppression of forest fires, reduced grazing, and lower rates of forest harvest for timber, fuel, and other products, are generally believed to have decreased annual water yields. Annual water yields from the 1.34 million acres of national forest lands in the North Platte River basin are estimated to have decreased by approximately 8 to 14 percent or 135,000 to 185,000 acre-feet per year, depending on the assumed stand history for the spruce-fir forests. Hydrologic models indicate that average annual water yields could be increased in the North Platte River basin by about 55,000 acre-feet per year if all 502,000 acres designated as suitable for timber harvest were regularly harvested on a sustained yield basis. Similar data are not available for other river basins in Colorado, although the overall trends are probably similar. This research looked at how reducing forest canopy affects the rate of spring snowmelt and water yield, how it affects evapotranspiration, what happens when the forest regrows, whether reducing forest density affects water yields if annual precipitation is a factor, the effects on water quality, and the necessity for water storage facilities to store the increased runoff. The report does not attempt to address the myriad of other issues that must be considered when evaluating various management alternatives for forested lands. Some of these issues include the numerous laws and regulations that affect land management, economic considerations, the downstream uses of water and water storage capacities, and the effects of forest management on recreation, local communities, aesthetics, and other plant and animal species.Sponsored by: Colorado River Water Conservation District, Colorado Water Resources Research Institute, Denver Water, Northern Colorado Water Conservancy District and financed in part by the U.S. Department of the Interior, Geological Survey, through the Colorado Water Resources Research Institute and Grant no. 01HQGR0077

Water chemistry profile comparisons of early- and mid-successional forests in coastal British Columbia

A comparison of water chemistry profiles was made between a mid-successional 70 to 90 year-old forest and an early-successional 18 year-old forest at the U.B.C. Research Forest. Western hemlock, Douglas-fir and western red cedar dominated the older ecosystem, while the younger ecosystem was composed of Douglas-fir and red alder. The concentrations of nutrients and other chemicals were compared in throughfall, forest floor and mineral soil leachates, saturated zone-water and stream-water. The younger ecosystem was found to have greater concentrations in the intermediate stages of the profiles, while stream-water concentrations were more similar between the ecosystems. The overall trend in the water chemistry profiles was best exemplified by the conductivity profiles. Conductivity was assumed to be equal in precipitation for both ecosystems, and was almost identical in stream-water. The soil leachate in the younger ecosystem, however, was two to three times greater in conductivity than in the older ecosystem. The major exception to this trend was the nitrate profile comparisons, where stream-water concentrations were 17 times greater in the younger than in the older ecosystem. However, biological nitrogen fixation by the red alder in the younger ecosystem results in substantially greater inputs. The concentrations of silica increased progressively through the profiles of both ecosystems, but the levels were consistently 40% to 100% higher in the younger ecosystem, suggesting a greater input of mineral cations to the younger ecosystem through soil mineral weathering. The higher concentrations of nutrients within the soil leachate stages of the younger ecosystem, combined with the failure of these higher levels to be observed in the saturated zone-water and stream-water (with the exception of nitrate), suggest that the younger ecosystem was relatively more efficient at retaining dissolved nutrients than the older ecosystem.Forestry, Faculty ofGraduat