Adam Wei is employing homegrown UBC technology to help manage the sustainability of China’s fir trees.

A major contributor to global warming is the increasing amount of carbon dioxide in the atmosphere. Land use management may be a means to countering global warming by increasing the carbon sink potential. Terrestrial carbon budgets were prepared for forested (Douglas-fir), agricultural (hay), and urban sites in Abbotsford, B.C. The results indicate that the greatest amount of carbon is stored in the forested sites, followed by the hay sites, with the lowest amount in the urban sites. To maximize carbon in storage the use of trees either as forests or in pockets within the landscape is the best option. To simulate and to expand the utility of these carbon budgets, the study used the CENTURY model. The results of the simulations indicate that forests are a major carbon sink as was found earlier. Carbon storage under hay is at a relative steady state, except during the cultivation years when it becomes a carbon source. Lawn in an urban setting is a carbon source. The results of the simulations suggest that management can be used to increase the carbon sink. It also indicates that soils are a major carbon pool representing 20% of the forest, 90% of the hay, and 95% of the lawn budgets. For the general public and decision-makers to become more aware of the impact of changing land use on carbon storage, at the lot, local, or regional levels, they require a userfriendly decision-making tool. A derivative of the CENTURY model, CLU (for CENTURY Land Use), was developed. It was designed to be user-friendly and at the same time maintain the integrity of the parent model. It allows the user to input site-specific data and obtain site related output carbon data on a component basis, which can be used to assess how a potential change in land use or management may affect the amount of carbon in storage. The model should be suitable as a research tool and for planning and educational purposes.

The ecology of blue duikers Philantomba monticola and red duikers Cephalophus natalensis was studied in three lowland coastal evergreen forests in Natal. Variation in population densities, estimated with numerous census techniques and between and within study areas permitted comparisons of habitat parameters. Both species are strictly diurnal, and are active between 18 and 40% of the nycthemeral cycle. Usually a pair of blue duikers occupy a permanent territory of about 0,7ha while red duiker home ranges, between 2 and 15ha, overlap extensively with each other and those of blue duikers. Habitat quality of both species is determined by canopy cover (stem densities, spatial patterning, and, diversity of the tree and shrub layers), tree to shrub ratios, and, bedsites. The main dietary item, freshly fallen leaves, is not that of a highconcentrate feeder as hypothesised. Food appears to be abundant while condensed tannins have no influence on duiker densities. Management recommendations include land acquisition, forest ecology research, monitoring interaction with other species, genetic aspects, translocations and captive propagation. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1990.

To understand the temporal dynamics of a forest, long-term direct observations are required. My study examined the long-term persistence of trembling aspen (Populus tremuloides Michx) and white spruce (Picea glauca (Moench) Voss) in the boreal mixed-wood forests of Riding Mountain National Park. A set of 266, disturbance-free, permanent sample plots were established in 1947 (stand age = 120 years) and followed through time for 55 years. My results indicate that although the density and basal areas of aspen do decline over the 55-year period, a successful regeneration and establishment occurs around 140 years. The long-term persistence of aspen is a result of clonal reproduction following the canopy breakup beginning around 130 years or earlier. This implies that the long-term persistence of both aspen and spruce occur and the expected succession to softwood dominance does not occur.

To understand the temporal dynamics of a forest, long-term direct observations are required. My study examined the long-term persistence of trembling aspen (Populus tremuloides Michx) and white spruce (Picea glauca (Moench) Voss) in the boreal mixed-wood forests of Riding Mountain National Park. A set of 266, disturbance-free, permanent sample plots were established in 1947 (stand age = 120 years) and followed through time for 55 years. My results indicate that although the density and basal areas of aspen do decline over the 55-year period, a successful regeneration and establishment occurs around 140 years. The long-term persistence of aspen is a result of clonal reproduction following the canopy breakup beginning around 130 years or earlier. This implies that the long-term persistence of both aspen and spruce occur and the expected succession to softwood dominance does not occur.

LiDAR (Light Detection and Ranging) is currently being used to extract the biophysical characteristics of forests. LiDAR can provide extensive information about tree canopies; pulses reflected back to the sensor can represent understory vegetation as well as partial tree canopies below the dominant trees. Canopy structure can yield valuable clues about the biodiversity, and processes affecting the ecology of forest stands. In addition, structural information can provide insight into other processes such as fire behaviour and the distribution of fuels. This thesis focuses in developing tools to better understand the forest structure. The tools are computer-based algorithms that use LiDAR data as input and provide output with detailed information about the different layers of vegetation in a forested area. Three main modules are used in this study: (1) treetop identification, (2) delineation of canopies for the dominant layer of vegetation, and (3) delineation of partial canopies underneath this dominant layer. The study area was located in the Greater Victoria Water District, west of Victoria, British Columbia, Canada. Nine plots were chosen to represent the study area. A complete census was conducted in the summer of 2005 to provide information about tree, diameter at breast height (DBH), and tree dominance (based on the criteria: suppressed, intermediate, codominant and dominant). Results show that the algorithm is able to properly identify and delineate the majority of trees in the study areas. The third module, partial canopy delineation, also presents promising results with the dataset used. Newer LiDAR systems, with higher number of returns, will definitely provide better datasets with more information of the different layers within the forest, increasing the identification and delineation of these partial trees. Need of new field data is a must for future work and for further tests with the algorithm.

Forests are the dominant terrestrial ecosystem in Ontario and were once widespread throughout much of eastern North America; in southern Ontario, forest cover has declined from 90% to approximately 17% in the past 200 years. Conversion of the surrounding landscape to urban and agricultural land uses creates edge effects which increase the impact of forest cover loss and threaten ecological integrity. Other impacts on forest ecological integrity include incompatible human activities, a generally inhospitable landscape matrix, and microenvironment changes, including those from chemical pollution and heat island effects. Coupled with direct degradation from human activities like free-riding, the altered forest microenvironment can facilitate increased invasion by opportunistic and competitive plant species, e.g. Alliaria petiolata (Brassicaceae). This tends to be worse in urban areas because of greater visitation that creates soil compaction, trampling, and more vectors to introduce the seeds of invasive species. Active management is often necessary in areas which have been degraded. Ecological restoration represents an important active management tool for urban forest protected area managers. The ecological restoration of the forest understory in altered and threatened habitats represents an important aspect of forest restoration. For this study, I tested the effectiveness of an ecological restoration using a multi-species assemblage approach with three native understory species to restore the herbaceous layer in Natchez Hills, an Environmentally Sensitive Policy Area in Kitchener, Ontario. The ecological restoration site was degraded and this reduced native plant species in the forest understory. The species selected, Caulophyllum giganteum (Farwell) Loconte & W.H. Blackwell (Berberidaceae), Podophyllum peltatum Linnaeus (Berberidaceae) and Maianthemum racemosum subsp. racemosum (Linneaus) Link (Asparagaceae), are widespread throughout eastern North America, and were selected for use in this study because of their persistence and relative abundance in Natchez Hills ESPA. Adult transplants were planted into 2 metre by 2 metre quadrats in different densities and shoot populations were monitored for two field seasons to determine if density played a role in early ecological restoration success. The methodology I designed for the ecological restoration was as practical as possible, given the real world financial and logistical constraints faced by many urban forest managers. Statistical analysis using repeated measures multivariate analysis of variance showed aerial shoot density did not have a significant effect on early restoration success rates (p > 0.05). However, there was a significant increase in restored species. Caulophyllum giganteum and Podophyllum peltatum shoot populations increased by over 97% at the ecological restoration site one year after transplanting. Maianthemum racemosum subsp. racemosum shoot populations increased by 51% at the site. For comparison, another study in the same forest reported early ecological restoration rates of 92% to 100% for herbaceous understory species, including C. giganteum and P. peltatum. Other North American studies using transplanted perennial herbaceous material reported average survival rates of 16.6% two years after planting (varying from 1.25% to 51.4% using eight herbaceous species in the Boston area), to 91% one year after restoration (varying from 42.1% to 100% using 19 herbaceous species of the deciduous forest in the Midwest). In instances where protected areas are degraded, active management and ecological restoration are often necessary tools. This ecological restoration demonstrated that the native herbaceous species used in this study are suitable for use in early ecological restorations in maple beech upland forests in the City of Kitchener. Using a practical and cost-effective methodology this ecological restoration experiment showed that it is possible to implement urban restoration of the forest understory in degraded areas, and to achieve success in early ecological restoration using native herbaceous forest understory species.

Tropical forests play a key role in determining the global carbon-climate feedback in the 21st century. Changes in rainforest growth and mortality rates, especially in the deep and least perturbed forest areas, have been consistently observed across global tropics in recent decades. Understanding the underlying causes of these changes, especially their links to the global climate change, is especially important in determining the future of the tropical rainforests in the 21st century. Previous studies have mostly focused on the potential influences from elevated atmospheric CO2 and increasing surface temperature. Because the rainforests in wet tropical region are often light limited, we explore whether cloudiness have changed, and if so, whether it is consistent with what is expected from changes in forest growth rate.

Typescript / Copies of two papers co-authored by the author, in back cover pocket / Bibliography: leaves 128-143 / 143 leaves, [60] leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1987

Bibliography: leaves 170-179. / vi, 179 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Describes a deterministic computer model for simulating forest dynamics which is the applied to a number of different timber harvesting scenarios in the mountain ash (Eucalyptus regnans F.Muell.) forests of Victoria, south-eastern Australia. Also looks at a number of new mathematical problems in the design of nature reserve systems. / Thesis (Ph.D.)--University of Adelaide, Depts. of Applied Mathematics, Environmental Science and Management, 2000?