In many parts of the United States, roughly 40% of forest is in non-industrial, private ownership, and in much of the eastern US, as much as 75% of all forest is in this category. Nationally, surveys and participation rates suggest most owners do not participate in traditional management or technical assistance programs, nor do they obtain professional advice prior to a management decision such as the sale of timber.

Twenty year record of vegetation change from long-term plots in Alaskan tundra
William A. Gould¹, Joel A. Mercado Diaz^1,2, Jess K. Zimmerman²
1. USDA Forest Service, International Institute of Tropical Forestry, Río Piedras PR,
2. University of Puerto Rico, Río Piedras, PR

Cross-ecosystem energy flows link streams and riparian forests. Forest harvesting alters the composition of riparian tree species, which can affect the structure and functioning of stream ecosystems through changes in terrestrial resource subsidies. We examined how variation in riparian forest composition (coniferous, mixed, deciduous) affects stream invertebrate and microbial consumers and subsequent leaf litter breakdown rates of red alder (Alnus rubra) and western hemlock (Tsuga heterophylla) in small coastal rainforest streams of southwestern British Columbia.

Landscape structure in the Eastern US experienced great changes in the last century with the expansion of forest cover into abandoned agricultural land and clearance of forest cover for urban development. Quantifying the changes in forest cover is a prerequisite to understanding the potential effects of those changes on ecological processes. In this paper, the spatial and temporal patterns of forest cover from 1914 to 2004 in the Gwynns Falls watershed in Baltimore, Maryland were quantified from historical forest maps and aerial photographs.

Landscapes at the Sevilleta LTER site are dominated or codominated by two perennial grasses from different biomes, Bouteloua eriopoda (black grama) from the Chihuahuan Desert and B. gracilis (blue grama) from the shortgrass steppe, and the Chihuahuan Desert shrub Larrea tridentata (creosotebush). We used a long-term removal study to examine inter-specific interactions between these dominant species, and to determine which species would eventually dominate following the removal of the others.

Woody vegetation encroachment threatens remaining native tallgrass prairie streams. Kings Creek is a prairie stream that was historically a mostly open canopy stream with little surrounding woody vegetation. Many reaches in Kings Creek have been subjected to woody expansion and now have a closed canopy. Closed canopy reaches receive less sunlight for primary producers and receive more leaf and wood material. Woody vegetation was removed from two 35 m reaches in order to determine the impact of woody expansion on stream ecosystem structure and function.

Land development practices result in compacted soils that filter less water, increase surface runoff and decrease groundwater infiltration. However, until now, there has been relatively little study of how hydrologic properties of lawns differ according to residential character such as year built or percent canopy cover. This study examines how soil infiltration rates and water retention properties of residential lawns differ according to social and physical factors that are readily attainable from national data sources.

Elevational Controls on Organic and Inorganic Nutrients in Stream Waters, Boulder Creek Watershed, Colorado Front Range

Jordan N. Parman and Mark W. Williams

Department of Geography and Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA

Woody encroachment and its effects on terrestrial ecosystems have been well-studied. However, the effect on riparian and aquatic ecosystems, specifically denitrification, has been lacking. Riparian areas of headwater prairie streams were historically dominated by grasses, but have become increasingly covered by woody vegetation. To determine potential consequences of woody plant invasion on denitrification, three adjacent reaches were delineated from two branches of King’s Creek, which drains Konza Prairie Biological Station.

Landscapes provide ecosystem services to agricultural systems by supporting pollinators and predators of crop pests, services valued at $US 3 and $US 4.5 billion/yr respectively. Habitat management is the practice of providing nectar, pollen and shelter to beneficial insects in cropping systems, often in the form of flowering strips. However, the potential for flowering strips to increase biocontrol and pollination depends on the existing abundances of beneficial insects in the landscape, and highly simplified landscapes may support fewer beneficial insects than more diverse landscapes.