Thesis (Ph. D.)--Wageningen University, 2006. / Thesis propositions sheet inserted. "Author's publications": p. 194-196. Includes bibliographical references (p. 151-180).

Thesis (M.S.)--Ohio University, March, 2004. / Title from PDF t.p. Includes bibliographical references (p. 30-38)

Thesis (M.S.)--Ohio University, August, 2004. / Title from PDF t.p. Includes bibliographical references (p. 34-42)

Thesis (M.S.) in Forestry--University of Maine, 2006. / Includes vita. Includes bibliographical references (leaves 87-96).

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 100-106). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 105-109). Also available on the World Wide Web.

Thesis (M.S.)--University of Wisconsin--Stevens Point, 2006. / Includes bibliographical references (leaves 76-82).

No description available.

[From Introduction] It has been said that, "If a nation saves its trees, the trees will save the nation." The truth of this assertion is apparent in many parts of the world today. In South Africa, fires and demands in the past for timber have led to extensive depletion of the Natural Forests. In many cases, natural revegetation has been slow to develop and deterioration of the soil has resulted. The desire to replace the tree cover and at the same time to meet an increasing internal demand for timber, has led to widespread planting of Pine and Bluegum. It is probable that more trees have now been planted than were destroyed in the past. The silviculturist however, who develops a pure stand on land which previously supported the mixed stand, should anticipate a change in soil properties as a natural accompaniment of such an undertaking. The nature of this change is the primum mobile of the present comparative study. The forest soils studied were taken in the Cape Province in the following areas:- Grahamstown; Amatola Mountains, District Alice; Witte-els-Bosch, District Humansdorp, during the course of a year. The physical and chemical properties, and the faunal composition of the soil samples were examined in relation to the different tree covers. Because of the necessity of taking large numbers of samples and thorough examination of these to arrive at a definite conclusion, the work is necessarily incomplete. It is felt however that the results obtained justify a further study of this aspect of soil biology.

Five plant associations and one Alluvial Complex are recognized for the Dry Subzone of the Interior Western Hemlock Zone of British Columbia. These include 22 phytocoenoses, here described as biogeocoenoses or forest types. Additionally 3 intrazonal Pinus ponderosa plant associations and 2 interzonal ecotones are discussed. In phytosociological analysis modified Zurich-Montpellier techniques are employed. For tree studies, dominance/ frequency/density (DFD) indices and standard forestry methods are applied. Phytocoenose descriptions are based on synthesis tables which include plant lists (total 538 species), habitat descriptions and tree growth data from 15.5 one-fifth acre plots. Forest types comprise: 1) Lichen association (Cladonietum) - open stands with Pseudotsuga menziesii as the edaphic climax dominant, occurring on xeric rock outcrops; 2) Moss association (Pachistimeto-Callier gonelletum) - closed stands with Tsuga heterophylla as the climatic climax dominant, occuring on me sic sites; this includes 6 forest types; 3) Aralia Oakfern association (Aralieto-Gymnocarpietum) - closed stands with Tsuga heterophylla, Thuja plicata as the edaphic climax codominants, occuring on moist sites; this includes 7 forest types; 4) Devil's Club association (Oplopanacetum) - closed stands with Thuja plicata as the edaphic climax dominant, occurring on wet sites; this includes 4 forest types; 5) Skunk Cabbage association (Lysichitetum) - open stands with Thuja plicata as the edaphic climax dominant, occurring on water-saturated ground; this includes 2 forest types; 6) Alluvial Complex - unstable riverside vegetation dominated by Populus trichocarpa. The Lichen, Skunk Cabbage and Alluvial Complex communities are floristically the most clearly defined, and are readily recognizable on the basis of lesser vegetation dominants alone. Recognition of mesic communities relies on a characteristic combination of species. The zonal (climatic climax) biogeocoenose is the Slope Normal Moss forest type of the Moss Association. The dynamic relationships of forest types are discussed. Secondary succession may go from the deforested stage directly to the climax, if edaphotope disturbance is minimal, but normally a pioneer-tree stage intervenes. This Subzone is unique in that, the pioneer stage of the zonal community may differ substantially from the climatic climax if humus is removed by fire. On mesic sites, proceeding from pioneer-conifer to climax stages, crown cover decreases and lesser vegetation increases. Tsuga heterophylla is the exclusive dominant of the climax forest„ In decreasing order of importance, as determined by DFD indices, Subzone trees are Tsuga heterophylla, Thuja plicata. Pinus monticola, Pseudotsuga menziesii, Betula papyrifera, Picea engelmannii, Larix occidentalis, Populus tremuloides, Pinus contorta, Populus trichocarpa. Abies lasiocarpa and Abies grandis. Most rapid tree height growth of Thuja plicata, Pseudotsuga menziesii, Pinus monticola and Picea engel-mannii occurs in Devil's Club communities; of Tsuga heterophylla, Larix occidentalis, Pinus contorta, Betula papyrifera, Populus tremuloides in Aralia Oakfern communities; and of Populus trichocarpa in Alluvial Complexes. Forest types are more productive in pioneer than in climax stages. Estimates of net primary productivity and standing crop of forest types for tree trunks of all tree species summed as one, showed that the greatest pioneer- conifer stand productivity (1251 kilogram/ hectare/year) and climax stand standing crop (180 x 10³ kg/ha) belong to the Devil's Club association, and the least productive (126 kg/ha/yr) and lowest standing crop (15 x 10³ kg/ha) to the Lichen association. It is concluded that biogeocoenotic classification provides a sound basis for land use planning in this region, and should be applicable to other areas. / Science, Faculty of / Botany, Department of / Graduate