Treesearch

The objective of this study was to update and extend the geographic range of a forest growth model for northern hardwoods, developed previously with data from the fourth Wisconsin inventory (Lin et al., 1996. Ecol. Model., 91: 193-211.). To this end, Lin's model was recalibrated with data from the recent fifth inventory of Wisconsin and Michigan, and with the addition of a site variable to reflect variations in land productivity. After the introduction of site effects, there were still statistically significant differences between the equations of ingrowth, upgrowth. and mortality for...

Conifer seedlings grown in bare-root nurseries are frequently damaged and destroyed by soil-borne pathogenic fungi that cause root rot. Relationships between nursery cultural practices, soils characteristics, and populations of potential pathogens in the soil were examined in three bare-root tree nurseries in the midwestern USA. Soil-borne populations of Fusarium spp. and Pythium spp. were enumerated as a function of soil depth in the upper 42 cm; red and white pine seedling root systems were assessed visually for signs of root rot. Soil organic carbon and resistance to cone penetration...

On-site observations, personal field journals, and in-depth interviews were used to examine qualitative aspects of the wilderness experience as a source of spiritual inspiration. Two groups of women kept personal journal accounts of their daily 'lived-experience' during one of two outdoor recreation trips; five participants went to the Boundary Waters Canoe Area Wilderness in northern Minnesota, and seven went to the Grand Canyon of northern Arizona. Journal entries were content-analysed, exploring the commonalties and idiosyncrasies found between individual accounts. Results were used to...

Drawing upon structural theory and social group perspectives, this study examined two propositions developed to explain the relationship between interracial contact and leisure preferences among African Americans and Whites. The first proposition stated that as interracial contact increases, the greater the probability of observing similarity in the leisure preferences of African Americans and Whites. The second stated that the probability of observing similarity in the leisure preferences will be greater among Whites with high or low interracial contact than observing similarity among...

Economic pressures on ecosystems will only intensify in the future. Increased population levels, settlement patterns, and increased incomes will raise the demands for ecosystem resources and their services. The pressure to transform ecosystem natural assets into marketable commodities, whether by harvesting and mining resources or altering landscapes through development, is likely to be enormous. Ecosystem management must establish means of assuring that these natural assets are used in a manner that provides high returns to human welfare, and of sustaining their abilities to continue...

In this review, we focus on the biotic parameters that are crucial to an understanding of the recruitment dynamics of North American boreal tree species following natural (fire, budworm infestation, windthrow) or human-induced (clearcut, partial cut) disturbances. The parameters we emphasize are (i) the production of seeds and asexual stems (both of which, we argue, are a function of basal area density), (ii) the dispersal of seeds by wind (or the dispersion of asexual stems) as a function of distance from source, (iii) dormant seed bank capacity, (iv) organic layer depth as a determinant...

Although major advances have been made in recent years in the physical science and technology of restoration, we think there is an equally important human side to restoration that has received little attention from researchers and practitioners. This journal provides a good case in point. Even though its editor, William Jordan III, is a principal spokesperson for the human side of restoration and frequently begins a journal issue with a moving editorial dealing with this topic, contributed articles from the social sciences and humanities are still few and far between. Jordan himself...

Although aesthetics and ecological sustainability are two highly regared values of forest landscapes, practices developed to manage forests for these values can sometimes conflict with one another. In this paper I argue that such conflicts are rooted in our conception of forest aesthetics as scenery, and propose that a normative, "ecological aesthetic" based on the writings of Aldo Leopold and others could help resove conflicts between aesthetic and sustainability values. I then offer suggestions on how we might advance an ecological aesthetic in policy and planning programs, on-the-ground...

Butternut (Juglans cinerea) is seriously threatened by a canker disease caused by Sirococens clavigignenti-juglandacearum, a fungus with no known sexual stage. This pathogen was first reported in 1967 and is now found throughout the native range of butternut, suggesting that it was introduced into North America. We used randomly amplified polymorphic DNA (RAPD) markers to examine genetic variation in S. clavigignenti-juglandacearun over a large portion of the native range of butternut. The 55 RAPD fragments were all found in all 86 isolates of the fungus. This complete monomorphism is...

This chapter provides information about the vegetation cover of the Assessment area. The types and areal extent of vegetation in the Highlands are of interest for many reasons. Vegetation cover largely determines the availability of habitat for terrestrial animals, plants, and other organisms. Vegetation cover strongly influences what uses {e.g., timber, forage, recreation) people can make of natural biological resources. Vegetation cover plays a major role in maintaining desired riparian and aquatic conditions (see USDA FS 1999a). Many people care (for aesthetic and other personal,...