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No description available.

There is growing interest in airborne lidar for forest carbon accounting and precision forestry purposes. Airborne lidar systems offer a cost-effective, versatile, operationally flexible and robust sampling tool for forest managers. The objective of this study was to develop and test lidar canopy surface enhancement and segmentation processes for estimating dominant above-ground biomass (DAB) in a harvested eucalypt forest on the Central Coast of New South Wales (Australia). The Crown Infill, Trim and Smooth (CITS) process, incorporating a series of filters, algorithms, and selective multi-stage smoothing, was used to enhance lidar canopy surfaces prior to segmentation. Canopy segmentation was achieved using a vertical crown template approach termed the Spatially and Morphologically Isolated Crest (SMIC) process. SMIC delineates dominant tree crowns by detecting elevated crown crests within a 3D lidar canopy surface. Consolidated crown units constitute the basic sampling, analysis and reporting units for wall-to-wall forest inventory. The performance, sensitivity and limitations of these procedures were evaluated using a combination of simulated forest models and actual lidar forest data. Automated crown polygons were used as a sampling template to extract dominant tree height values which were converted to DAB estimates via height-to-biomass relationships derived from field survey and on-site destructive sampling. Results were compared with field based tree height and biomass estimates. Compared against a manually derived crown map from a 2ha field plot, canopy segmentation results revealed a producer???s accuracy of 76% and overall accuracy of 67%. Results indicated a trend toward greater crown splitting (fragmentation) as trees increase in age, height, stem diameter and crown size. Extracted dominant tree height values were highly correlated with ground survey height estimates (r2 0.95 for precision survey and r2 0.69 for standard survey). There was also no significant difference between SMIC and manual crown height estimates. SMIC units overestimated ground-based DAB by 5%; this increased to 36% with the inclusion of segmentation errors. However, SMIC estimation of total plot above-ground biomass (AGB) was within 9% of the ground-based estimate. Results are encouraging considering the mixed-species, multi-aged composition of the forest, and the combined effects of SMIC segmentation and lidar height errors.

This study documented effects of fragmentation and disturbance on a coastal eucalypt dry open-forest plant community at Port Stephens-Myall Lakes, south-eastern Australia. The study evaluated the relative influence of fragment size (range &lt1-75ha), fragment or edge age (&lt 1-25y), time since fire (5-25y) and anthropogenic disturbance (minor, major) on microclimate, native plant species richness and weed invasion. Plots were sampled for native and exotic species richness per 25 m2 and edge transects for light, soil moisture, soil temperature, vegetation structure, native species richness and exotic species richness and cover. Depths of edge influence (DEI) were all &lt 20m inside the forest edge. Younger edge zones were lighter, had hotter and drier soils and more native species than forest interiors. Older edge zones were shadier, had warmer and moister soils and fewer native species than forest interiors, due to vegetation thickening in the edge zone. Light and soil moisture followed linear or monotonic edge-to-interior gradients in younger edges, but more complex patterns in older edges. Soil-temperature DEI decreased with increasing edge age. Fragment size had little influence on edge effects, but those for light developed more rapidly in smaller fragments, and recent fire was associated with reduced richness in edge zones of smaller fragments. Both anthropogenic disturbance and fire enlarged DEI for native species richness. Major anthropogenic disturbance coupled with fragmentation produced a stronger and more immediate loss of native species than fragmentation alone. Small fragments with minor disturbance had fewer native species per 25 m2 than larger fragments, but only after &gt10y since fragmentation. Analysis of forest interior portions of transects revealed that edge effects, and possibly disturbance, were largely responsible for this loss of native species with time, rather than effects of area. Despite a viable soil seed bank in fragments and the surrounding matrix, weed invasion in fragments was minimal. Exotic species were concentrated in edge zones, and were promoted by major anthropogenic disturbance within fragments. Results were highly dependent on fragment or edge age, and external influences of fragmentation (edge effects and disturbance), were more important than biogeographic (area-driven) factors. Impacts of fragmentation were compounded when combined with disturbance.

Thesis (Ph. D.)--Oregon State University, 1963. / Typescript. Includes bibliographical references (leaves 255-268). Also available on the World Wide Web.

Graduation date: 1970

Thesis (M.S.)--Oregon State University, 1967. / Typescript (photocopy). Includes bibliographical references (p. 46-49). Also available on the World Wide Web.

Thesis (M.S.)--University of Washington, 2006. / Includes bibliographical references (leaves 52-57). Issued also electronically via World Wide Web in PDF format.

Thesis (Ph. D.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science in Biology." "A thesis entitled"--at head of title. Bibliography: leaves 48-55.