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Full-Text Articles in Physical Sciences and Mathematics
Using A Mensuration Approach With Fia Vegetation Plot Data To Assess The Accuracy Of Tree Size And Crown Closure Classes In A Vegetation Map Of Northeastern California, Samantha J. Gill, Jeff Milliken, Debby Beardsley, Ralph Warbington
Using A Mensuration Approach With Fia Vegetation Plot Data To Assess The Accuracy Of Tree Size And Crown Closure Classes In A Vegetation Map Of Northeastern California, Samantha J. Gill, Jeff Milliken, Debby Beardsley, Ralph Warbington
Natural Resources Management and Environmental Sciences
The accuracy of the Lassen-Modoc vegetation map was assessed using data from a grid of permanent Forest In-ventory and Analysis (FIA) plots in conjunction with a fuzzy logic approach. This paper presents the results for the Modoc National Forest. The main foci of this paper are the methods and results for assessing the accuracy of tree size and crown closure classes using a mensurational approach based on calculations made from the plot data. This approach proved very useful in conjunction with fuzzy accuracy methods. Higher error rates reported for crown closure classes may be due to a variety of factors …
Peak Flow Responses To Forest Practices In The Western Cascades Of Oregon, Usa, R. L. Beschta, M. R. Pyles, A. E. Skaugset, C. G. Surfleet
Peak Flow Responses To Forest Practices In The Western Cascades Of Oregon, Usa, R. L. Beschta, M. R. Pyles, A. E. Skaugset, C. G. Surfleet
Natural Resources Management and Environmental Sciences
The effects of clearcut silviculture (road building, clearfelling, cable logging, and site preparation) were evaluated using long-term peakflow records for three small watersheds (60–101 ha) and six large basins (62–640 km2) in the western Cascades of Oregon, USA. After a calibration period, two of the small watersheds were treated while the third remained untreated (control). Analysis indicated that peakflow increases following treatments were dependent upon peakflow magnitude. Peakflow increases averaged approximately 13–16% after treatment for 1-yr recurrence interval events, and 6–9% for 5-yr recurrence interval events. For the six large basins, multiple linear regression analyses of peakflows relative …
Modeling Conifer Tree Crown Radius And Estimating Canopy Cover, Samantha J. Gill, Gregory S. Biging, Edward C. Murphy
Modeling Conifer Tree Crown Radius And Estimating Canopy Cover, Samantha J. Gill, Gregory S. Biging, Edward C. Murphy
Natural Resources Management and Environmental Sciences
Models of tree crown radius were developed for several conifer species of California. Typical forest inventory variables (DBH, height, height-to-crown base, crown class, basal area per hectare, and trees per hectare) were considered as independent variables in model development. Models were fitted using both ordinary and weighted least squares methods. It was found that for the species studied, an ordinary least squares linear regression with DBH as the only independent variable was appropriate. For some species studied, the addition of other independent variables provided minor improvements over the model with only DBH. These models of crown radius could be summed …