Treesearch

Optimum fertilization levels are often determined solely from nursery growth responses. However, it is the performance of the seedling on the outplanting site that is the most important. For Pinus species seedlings, little information is known about the field performance of plants cultured with different nutrient rates, especially with exponential fertilization. In this study, Chinese pine (Pinus tabulaeformis Carr.) seedlings grown in 187 ml containers were fertilized exponentially in 6 treatments ranging from 10 to 120 mg N seedling-1 for 25 weeks before outplanting. Dry mass and N...

Pyrenophora semeniperda is a generalist fungal pathogen that occurs primarily on monocot seed hosts. It is in the phylum Ascomycota, which includes both self-compatible (homothallic) and self-incompatible (heterothallic) species. Homothallic fungal species contain complementary mating-type (MAT) idiomorphs in a single unikaryotic strain, while heterothallic strains contain a single MAT idiomorph requiring interaction between strains of complementary mating-types for sexual reproduction to occur. Because the majority of P. semeniperda strains contained either MAT1 or MAT2, this species was...

Vegetation surveys at Zion National Park (Zion), Utah, have contributed to our understanding of plant community patterns and their relationship to environmental factors. Previous authors used vegetation plot data to characterize vegetation types at Zion following conventional procedures that emphasize spatial discreteness and dominant species. We developed and applied an alternative approach for community characterization that emphasizes nondiscrete presence-absence patterns and is compatible with the individualistic concept. We reanalyzed existing plot data from Zion using coalition...

Management of many dry conifer forests in western North America is focused on promoting resilience to future wildfires, climate change, and land use impacts through restoration of historical patterns of forest structure and disturbance processes. Historical structural data provide models for past resilient conditions that inform the design of silvicultural treatments and help to assess the success of treatments at achieving desired conditions. We used dendrochronological data to reconstruct nonspatial and spatial forest structure at 1860 in fourteen 0.5 ha plots in lower elevation (∼1900–21...

Water is a critical resource for humans and ecological systems in the western United States. Aquatic ecosystems including lakes, rivers, riparian areas and wetlands, are at high risk of climate impacts because they experience relatively high exposure to climate fluctuations and extremes. In turn, impacts arising from climate change are far reaching because these systems tend to support a disproportionate amount of the biodiversity and ecological services in the landscapes within which they exist (Capon et al., 2013). A number of reviews are available that detail threats to riparian and...

In the National Forests of northern Colorado, there is a backlog of over 140,000 slash piles slated to be burned, most of them coming from post-mountain pine beetle salvage logging and hazard reduction treatments. Burning slash piles can create openings in the forest that remain treeless for over 50 years, and can also have the short-term impacts of increasing nutrient availability and creating opportunities for weed establishment. Working with managers, RMRS researchers have evaluated the available treatments for short-term rehabilitation of both smaller, hand-built and larger, machine-bui...

In the west, fire exclusion, timber harvest, and last century’s climate led to copious regeneration on millions of ha that now need tending. Without treatment, overcrowding increases competition, snow and ice damage potential, and ladder fuels. Limited funding prevents treating all of the affected ha, but by selling small trees for wood pellets, biofuel, or methanol, costs would decrease and more ha could be cleaned. In the northern Rocky Mountains, 8 –10 tree species can occur in young forests, and until this study, information on foliage nutrient concentrations and leaching from saplings...

Over the past 100 years, experimental forests and ranges (forests) have supported research that produced long-term knowledge about our forests and ranges, and their resources. These forests are living laboratories and are rare assets that serve as places to conduct forest research to meet society’s natural resource needs.

Downscaled climate models provide projections of how climate change may exacerbate the local impacts of natural hazards. The extent to which people facing exacerbated hazard conditions understand or respond to climate-related changes to local hazards has been largely overlooked. In this article, we examine the relationships among climate change beliefs, environmental beliefs, and hazard mitigation actions in the context of wildfire, a natural hazard projected to be intensified by climate change. We find that survey respondents are situated across a continuum between being ‘believers’ and...

Primary wood products manufacturers generate significant amounts of woody biomass residues that can be used as feedstocks for distributed-scale thermochemical conversion systems that produce valuable bioenergy and bioproducts. However, private investment in these technologies is driven primarily by financial performance, which is often unknown for new technologies with limited industrial deployment. In this paper, we use shift-level production data collected during a 25-day field study to characterize the conversion rate and system productivity and costs for a commercially available...