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Incomplete knowledge of the ecological functions of small streams and their riparian zones, particularly their roles in larger watershed and landscape contexts, contributes to confusion and debate about the levels of riparian vegetation retention required along small streams for the purpose of protecting aquatic ecosystems, riparian wildlife, and water quality. As a consequence, there are marked differences in riparian forestry practices and management among jurisdictions throughout North America. To aid in resolving these issues, a symposium on small streams and their riparian zones was held at The University of British Columbia from 19 to 21 February 2002, which brought together scientists, managers, and practitioners and provided a forum for the presentation and discussion of emerging research results. This special issue includes a selection of papers presented at that symposium as well as one solicited paper. [ABSTRACT FROM AUTHOR]

Many hiking trails traverse the forests and public lands across North America. It has therefore become important for federal management to gain an understanding of total use on these trails. However, there has never been a formal attempt to estimate hiking on these long, backcountry trails. This paper presents an approach that utilizes two survey instruments (exit-site tallies and a trail-user questionnaire) and two primary estimation components (standard and augmented sites) to estimate hikers over a spatial and temporal span. For illustrative purposes, the methodology is applied to a 175 km segment of the Appalachian Trail from 1 June through 14 August 2007. Two alternative estimation methodologies are presented and compared. The model-based approach may be preferred to the design-based approach when sample size is small because it smoothes erratic strata estimates and yields smaller standard errors. However, the design-based approach relaxes an assumption and is more appropriate as sample size increases. In our survey of the Appalachian Trail, there was a 5.6% difference between the visitation estimates based on these two approaches, and such stability reinforces confidence in the methodology. [ABSTRACT FROM AUTHOR]

Prediction of forest composition and structure over multiple generations of trees is often hampered by limited data on understory tree dynamics and the highly variable process of canopy recruitment in forest openings. In this paper, we describe a model of sapling dynamics and overstory recruitment for CANOPY, a spatially explicit, crown-based, individual-tree model of gap dynamics. The model incorporates gap size as a predictor of sapling recruitment and height growth, and it mimics the processes of sapling release, gap capture, and lateral gap closure. Calibration data were derived from 12 data sets with a wide range of stand ages and disturbance history in northern hardwood stands in the Great Lakes region, USA. The model accounted for 30%-62% of the variation in sapling density, composition, and growth rates. Predicted effects of increasing gap size on growth rate were similar to observed trends. Growth equations that included gap size as an independent variable generally gave better predictions of sapling density, species composition, and growth rates than equations based on conventional plot-level competition metrics. Long-term, 1000-year simulations produced estimates of stand basal areas and tree density in each size class that are close to the mean observed values for old-growth stands in the region. [ABSTRACT FROM AUTHOR]