Browsing by Author "Kigomo, B.N."
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Item Bigley Wood Management October 1980-September 1990.(Kigomo B, 1980) Kigomo, B.N.Bagley wood is run under forestry commission is dedicated Scheme Basis II. This scheme requires wood owners to manage their woods in accordance with a plan of operations approved by the Forestry Commission. Following these requirements is paramount if the owners wish to qualify for a management grant aid. The present plan aims to meet these requirements by quantifying forest produce for planning purposes, for sales and control of resources.Item Crown and Bole Diameter Relationship in Brachylaena Huillensis and Its Application to Silvicultural Interventions(1991) Kigomo, B.N.Among the essential features of a trees life cycle are some basic aspects of morphological structure and growth in relation to environment. It has been shown that the form of the stem is, a function of the crown (Larson, 1963). An understanding of the relationship between the morphological features therefore has a practical bearing on forest management in terms of growth and yield as well as genetic improvement of a tree.Item Crown-Bole Diameter Relationship of Juniperus Procera (Cedar) and its Application to Stand Density Control and Production Survey in Natural Stands(1980) Kigomo, B.N.; Kenya Agricultural Research Institute, Forestry Research Department, MugugaJuniperus procera Hochst. ex Endl (East African Pencil Cedar) is an indigenous ever green dioecious timber tree belonging to the family Cupressaceae. It is a slow growing species but can attain a height of 36 metres. Juniperus procera is widely distributed in drier highland forests of Kenya from 1,100 to 2,500 m above sea level (a.s.l.) and mean annual rainfall of 1,000 to 1,350 mm (Dale and Green- way, 1961). The Cedar crown is distinctly pyramidal in the early stages but spreads out with age. Due to its voluminous size, one tree can produce a relatively large quantity of timber although older trees are often piped due to heartrot fungus, Fomes Juniperinus Fr. The tree's heart wood and sapwood are well distinct both in appearance and utility. The sapwood is white, representing nearly two-thirds of the timber by volume in pole stage trees and is rapidly destroyed by termites. The heartwood is dark red, extremely resistant to termine attack and very durable in the ground.Item Diameter increment and growth of Podoearpus trees in natural forests(FRD/KARI, 1985) Kigomo, B.N.; Forestry Research Department; Kenya Agricultural Research InstituteStems of Podocarpus gracilior and P. milanjianus were selected at Kaptagat natural forest stands for current diameter increment assessments. measurements were carried out over several growth periods. Under the local prevailing climatic conditions, P. gracilior showed better diameter increment than P. milanjianus though its periodic mean annual diameter increment of J.34 cm is low. Lack of free growth conditions may partially explain the low rate of growth. No significant relationship was noted between initial diameter or individual trees and their corresponding mean annual diameter increment in both podocarpus species. Although the available data were limited, it may be tentatively concluded that for these species and such locality to reach a diameter at breast height (DBH) (OB) of 45 ern or 60 cm, P. grocior requires 128 and 175 years respectively. P. milanjianus would require 136 and 220 years to attain the Fer mentioned DBH (On), respectively.Item Observations on the Growth and Yield of Oxytenanthera Abyssinica (A. Rich) Munro in Plantation(1985) Kigomo, B.N.; Kamiri, J.F.; Forest Research Department, Kenya Agricultural Research Institute, MugugaThe seed source was Zimbabwe Forest Department. Seeds were sown in an open bed and then put out as transplants in nursery beds after three months. The transplants were kept in the nursery for two years at the end of which the seedlings were planted out as unreplicated trial at Muguga, which has an altitude of 2100 m asI, mean annual rainfall of 970 mm and a mean monthly temperature of 16 C (EAAFRO, 1975).Item Possible factors limiting the growth of an aquatic weed, hydrilla verticillata (L.F.) Royle under tropical conditions(1983) Kigomo, B.N.The aim of this study was to help understand the possible factors lirniting the growth 'of an aquatic weed Hydrilla verticil/ata in the littoral waters of Lake Victoria. The study was confined to investigation of inorganic' carbon as source of nutrient and a possible biocontrol of the weed by fresh water snails, Lymnea natale.nsis and Bulinus spp found in the lake. A series of experiments were conducted for the purpose of evaluatiilg these factors. From the studies it was observed that Hydrilla is able to photosynthesize in a medium where HCO-) ions are predominant. The weed would thus be at an advantage where carbon dioxide i~ reduced or lacking as a result of local ecological effects. Hydrilla has a maximum growth in a mcdiu:il of 220 mg per litre (predominantly HCO-) iam) optimum total alkalinity. This would mean that Hydrilla can do weB in calcareous waters, an observation weB supported by the fact that the weed flourishes well in many hard water habitats. Consl1mption of Hydrilla by snails was 34.30/0 of the totul available biomac;s. These results show that while fresh water snails may be playing relatively little role in the control of Hydrilla, it is mo;.t likely that the low inorganic carbon source in Lake Victoria of total alkalinity 55.3 mg per litre ~C02 + HCO-]) may be contributing to the low growth of the aquatic weed. Further studies on nutrient require,ments by Hydrilla in relation to the nutrient status in Lake Victoria littoral zone may contribute profitably to the,Present conclusions.
