No description available.

No description available.

No description available.

Some species of sundew (Drosera spp.), harvested from the wild for use in homeopathic cold remedies, are now endangered. This research consisted of two experiments in hydroponic production of sundew. The first investigated the effects of four nitrogen (N) fertilization levels (0.0, 5.1, 25.5 or 51.0 mg/L added N) and three harvest methods (after two months, four months, and sequential harvest at two and four months) on the growth of Drosera adelae (F. Muell.). In addition, the effect of N on the production of a medicinal active ingredient in D. adelae was examined. The second experiment investigated effects of the same nitrogen treatments in combination with three substrates (long fiber sphagnum, peat or rockwool) on growth. The growth rate of D. adelae was greatest at low levels of nitrogen fertilization, and slowed after two months of growth. Plants that were sequentially harvested had the lowest growth rate among all the harvest method treatments. Young plants and plants that received little or no N fertilizer had a greater water concentration than the other plants. Substrate and N level interacted, but generally peat and rockwool produced greater yields than did sphagnum. The medicinal compound plumbagin and a similar but unidentified compound were detected in the leaf extracts of D. adelae. However, whether N fertilization influenced the concentration of these compounds remains inconclusive.

This research focused on the secondary succession of spring flora occurring within pits of windthrows located in the area described as Ginn/ Nixon Woods, an old growth beech-maple forest community that transitions to a mixed mesophytic forest community, approximately 12 miles north of Muncie, IN. More specifically, this research sought to identify the vegetative production capacities of pits as well as determine the extent to which pit microtopography and light influx affect the production of spring flora.In all sixty plots were established--30 test plots within the confines of windthrow pits, and 30 control plots, each one just six feet away from a test plot on undisturbed forest soil. One sampling period occurred in 1993 (just prior to leafing); four sampling periods occurred in 1994 (two prior to leafing and two after leafing). Species presence, density and cover data were used to produce two-dimensional ordinations for examination. Species presence, plot depth, slope, and light data were subjected to the Spearman Rank Order Correlation Test to determine the extent of influence pit microtopography and light influx have on spring flora.Examination of the data clearly showed that disturbed areas known as windthrow pits experience a significant decline in vegetative production--at least for a few years but likely for many years, after the initial disturbance or windthrow occurs. The data also clearly showed that over time windthrow pits eventually recover vegetative production.The recovery of vegetative production in pits was shown to have a positive correlation with plot depth; that is to say, as pit depth decreases, vegetative diversity increases. Standing water in pits, though not recorded statistically, was observed in the field as having a strong negative impact on vegetative recovery. Consequently, the environmental factors that work together to affect the topographical recovery of the pit to an elevation equal to or greater than the surrounding forest floor were found to be critical in the vegetative recovery of pits. This researcher has appropriately termed this recovery process as "elevation equilibrium," since the end result is a pit whose topographical relief has given way to a relatively static elevation equal to adjacent undisturbed areas of the forest floor.Unlike plot depth, the amount of slope in pits did not seem to play a significant role in reducing or encouraging vegetative recovery. Likewise the amount of shade cast on pits prior to leafing, and the size and/or presence of gaps in the canopy after leafing, appeared to have little influence on the recovery of spring flora. When plant diversity data for each test plot was correlated with its slope, pre-leafing light influx and post-leafinglight influx data using the Spearman Rank Order Correlation test, it found no significant relationships between any of the sets of variables. / Department of Natural Resources and Environmental Management

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliographical references.

Browse biomass production of Salix spp. and Betula glandulosa on a wetland in central British Columbia is estimated. Based on an extensive review of much of the literature pertaining to shrub biomass and shrub density estimation, a technique combining regression estimates of average stem biomass with a density estimate obtained using the corrected point distance method was applied. It was found that the best regression relationships were obtained using natural logarithmic transformations of the dimension and biomass variables. It was possible to obtain acceptable biomass equations for the four Salix species encountered without differentiating between the species. More accurate predictions of biomass were achieved using site specific equations and equations based on pooled site data than with general equations. It was concluded that the value of the approach taken is limited if site specific equations are required because of the considerable time required for sample collection and preparation. / Forestry, Faculty of / Graduate

No description available.

No description available.

Wong, Man Shan Michelle. / Thesis submitted in: November 2006. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 148-167). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abstract --- p.III / Table of contents --- p.VI / List of Tables --- p.X / List of Figures --- p.XI / List of Plates --- p.XIV / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Wetlands --- p.1 / Chapter 1.2 --- Importance of wetlands --- p.3 / Chapter 1.3 --- Wetland plants --- p.7 / Chapter 1.4 --- Adaptations of wetland plants to flooding --- p.7 / Chapter 1.5 --- Effects of hydrology on wetland plants --- p.13 / Chapter 1.6 --- Other factors affecting plant growth in wetlands --- p.16 / Chapter 1.7 --- Wetlands in the world --- p.19 / Chapter 1.8 --- Wetlands in Hong Kong --- p.19 / Chapter 1.8.1 --- Mai Po Inner Deep Bay Ramsar Site --- p.19 / Chapter 1.8.2 --- Wetland conservation in Hong Kong --- p.21 / Chapter 1.9 --- "Successful cases and constraints on wetland restoration, creation and conservation" --- p.22 / Chapter 1.9.1 --- The Ramsar Convention and wetland conservation --- p.22 / Chapter 1.9.2 --- Constraints in wetland restoration and creation --- p.32 / Chapter 1.9.3 --- Cases of wetland restoration and creation --- p.32 / Chapter 1.9.3.1 --- Restoring the habitat of endangered bird in southern California --- p.33 / Chapter 1.9.3.2 --- Creating tidal wetlands in San Diego Bay --- p.33 / Chapter 1.9.4 --- Constraints on wetland restoration and creation in Hong Kong --- p.33 / Chapter 1.9.4.1 --- Small scaled projects --- p.33 / Chapter 1.9.4.2 --- Lack of long-term management --- p.34 / Chapter 1.9.4.3 --- Lack of clear goals and objectives --- p.34 / Chapter 1.10 --- "Objectives, significance and outline of the present study" --- p.35 / Chapter 1.10.1 --- Research objectives --- p.35 / Chapter 1.10.2 --- Significance of the research --- p.35 / Chapter 1.10.3 --- Outlines of the thesis --- p.37 / Chapter Chapter 2 --- Growth performance of selected species of freshwater emergents under different levels of submergence in a natural wetland / Chapter 2.1 --- Introduction --- p.38 / Chapter 2.2 --- Materials and Methods --- p.41 / Chapter 2.2.1 --- Site description --- p.41 / Chapter 2.2.2 --- Planting --- p.42 / Chapter 2.2.3 --- Sampling --- p.42 / Chapter 2.2.3.1 --- Water --- p.43 / Chapter 2.2.3.2 --- Soil --- p.43 / Chapter 2.2.3.3 --- Plants --- p.43 / Chapter 2.2.4 --- Analysis --- p.43 / Chapter 2.2.4.1 --- Water --- p.43 / Chapter 2.2.4.2 --- Soil --- p.47 / Chapter 2.2.4.3 --- Plants --- p.47 / Chapter 2.2.5 --- Statistical analysis --- p.48 / Chapter 2.3 --- Results and Discussion --- p.48 / Chapter 2.3.1 --- Water quality in the trial plots at the Mai Po Marshes Nature Reserve --- p.48 / Chapter 2.3.2 --- Soil properties in plots under different levels of submergence at the Mai Po Marshes Nature Reserve --- p.53 / Chapter 2.3.3 --- Growth of freshwater emergents under different submergence levels --- p.59 / Chapter 2.3.3.1 --- Aboveground biomass --- p.59 / Chapter 2.3.3.2 --- Plant nutrient concentrations --- p.66 / Chapter 2.3.3.3 --- Plant nutrient yields --- p.67 / Chapter 2.4 --- Conclusions --- p.76 / Chapter Chapter 3 --- Growth performance of selected species of freshwater emergents under different levels of submergence in a created wetland / Chapter 3.1 --- Introduction --- p.78 / Chapter 3.2 --- Materials and Methods --- p.80 / Chapter 3.2.1 --- Site description --- p.80 / Chapter 3.2.2 --- Planting --- p.80 / Chapter 3.2.3 --- Sampling --- p.80 / Chapter 3.2.3.1 --- Water --- p.80 / Chapter 3.2.3.2 --- Soil --- p.84 / Chapter 3.2.3.3 --- Plants --- p.84 / Chapter 3.2.4 --- Analysis --- p.85 / Chapter 3.2.4.1 --- Water --- p.85 / Chapter 3.2.4.2 --- Soil --- p.86 / Chapter 3.2.4.3 --- Plants --- p.86 / Chapter 3.2.5 --- Statistical analysis --- p.87 / Chapter 3.3 --- Results and Discussion --- p.87 / Chapter 3.3.1 --- Water quality in the freshwater marshes at the Hong Kong Wetland Park --- p.87 / Chapter 3.3.2 --- Soil properties in the freshwater marshes under different levels of submergence at the Hong Kong Wetland Park --- p.92 / Chapter 3.3.3 --- Growth of freshwater emergents under different submergence levels --- p.100 / Chapter 3.3.3.1 --- Aboveground biomass --- p.100 / Chapter 3.3.3.2 --- Plant nutrient concentrations --- p.105 / Chapter 3.3.3.3 --- Plant nutrient yields --- p.109 / Chapter 3.4 --- Conclusions --- p.112 / Chapter Chapter 4 --- Growth performance of selected species of freshwater emergents under different levels of submergence and soil types in a greenhouse pot experiment / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.2 --- Materials and Methods --- p.115 / Chapter 4.2.1 --- Experimental setup --- p.115 / Chapter 4.2.2 --- Harvesting --- p.117 / Chapter 4.2.3 --- Tissue analysis --- p.117 / Chapter 4.2.4 --- Statistical analysis --- p.117 / Chapter 4.3 --- Results and Discussion --- p.118 / Chapter 4.3.1 --- Aboveground biomass --- p.118 / Chapter 4.3.2 --- Plant nutrient concentrations --- p.128 / Chapter 4.3.3 --- Plant nutrient yields --- p.134 / Chapter 4.4 --- Conclusions --- p.140 / Chapter Chapter 5 --- General Conclusions / Chapter 5.1 --- Summary and implications of major findings --- p.142 / Chapter 5.2 --- Limitations of the study --- p.144 / Chapter 5.3 --- Further investigations --- p.145 / References --- p.148