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Recovery of tropical rain forest in Gogol Valley, Papua New Guinea was monitored for 2 years following clear-fel1ing in the wet and dry seasons. Further redevelopment, reconstructed by measurements of regrowth of known ages from 1.5-10.8 years, were compared with forest heavily disturbed by fire 55 years ago and primary forest. The vegetation, survey was assessed principally by Counting and measuring trees. Because of the importance of soil seed bank in influencing vegetation recovery processes, special attention was given to the spatial and temporal changes in the soil seed bank and the seed rain which supplies it. The major findings were: (1) vegetation recovery was rapid and 97% of all colonizing trees regenerated from seeds while 3% were resprouts; (2) regrowth after felling in the dry-season differed from that following wet-season felling in having lower density, slower growth and mostly comprised resprouting tree species; (3) after 10 years, regrowth is composed principally of large pioneer trees (65% of basal area or 64% of stems); (4) the 55 year-old forest also had many (48%) pioneer trees: much of the forest in the area is of this kind and may be classified as advanced secondary forest; (5) forest soil seed bank following felling was rapidly depleted due to germination, but was rapidly replaced as early pioneer herbs matured and set seed. Trees in soil seed bank do not approach that of primary forest until after 10 years of regrowth; (6) the intensity of pioneer trees' seed rain was correlated with the fecundity of nearby parent trees and clearly controlled soil seed bank redevelopment. There was evidence of dispersal of pioneer seeds several hundred metres into an isolated area of closed forest; (7) trees left uncut following felling contribute significantly to seed rain and therefore to soil seed bank.

Genetic variation in Calamus subinermis was investigated in a provenance cum progeny trial and a study on some quantitative morphological traits. These studies show that variation occurs within and among populations of the species. Genetic gain was estimated for provenance and family selection at a range of selection intensity based on some economic traits. A karyomorphological study on C. subinermis and C. caesius reveals little variation in the chromosome morphology between and within species. The flowering and fruiting phenology of C. subinermis, C. caesius, C. manan and C. trachycoleus was elucidated. Except for the relatively opportunistic C. subinermis, in which floral initiation occurred at about four-month intervals, flowering and fruiting of the Calamus species investigated exhibited a regular annual pattern. Unravelling of the pollination mechanism and floral biology of C. subinermis and C. caesius in this project enables understanding of the breeding system and is important in breeding programmes. Pollination mainly by small noctuid and pyralid moths, which have small foraging ranges, partly accounts for the observed divergence among geographically isolated populations of C. subinermis. The discovery of andromonoecy in C. subinermis, together with the potential bisexuality in the other generally dioecious calamoid genera, calls for modification in the present system of classification for the tribe Calameae, and has implications for natural and artificial pollination. Several rattan mensuration techniques were developed. Growth and yield models based on the Richards function were constructed for C. caesius. These techniques and models will contribute to the conservation with wise use of rattan resources. Recommendations for further research are given for attaining the goal of the project.

Student Number : 0009911A - PhD Thesis - School of Geography, Archaeology and Environmental Studies - Faculty of Humanities / The study of sacred leadership at Mapungubwe involves an analysis of how the emerging elite centralised rainmaking and other public rituals. These developments occurred in the Shashe-Limpopo basin between AD 1000 and AD 1300. Mapungubwe was the last in a sequence of capitals in the basin. The first was Schroda (AD 900-1000), followed by K2 (AD 1000- 1220) and then Mapungubwe (AD 1220-1300). This sequence corresponds to a series of cultural, socio-political and economic transformations that led to class distinction and sacred leadership, two distinctive features of the region’s early state system. The development of Mapungubwe was a local indigenous accomplishment that occurred in the prehistoric period but in the relatively recent past. This offers possibilities for using current indigenous knowledge to develop relevant ethnographic models. Over a period of four years, I explored Venda, Sotho-Tswana and Shona traditional agriculture strategies and belief systems through their oral histories, cosmologies and practices. I identified three systems of rainmaking practices. Practice A is associated with kin-based chiefdoms. Practise B exists among class-based polities with sacred leadership. Practice C represents the devolution of complexity after the disintegration of the Zimbabwe culture. These data provide models to clarify the roles of rainmaking and agriculture in the evolution of Mapungubwe.