SHADING EFFECTS ON GROWTH AND PARTITIONING OF PLANT BIOMASS IN PASPALUM CONJUGATUM BERG

Glasshouse studies were carried out to determine the effect of shading on the growth and partitioning of plant biomass in Paspalum conjugatum Berg. The invidual leaf rate expansion, final leaf are, specific leaf area, and the whole plant vegetative growth pattern, dry-matter production, leaf area as well as biomass partitioning were significantly influenced by shading. At the 75% level of shading, P. conjugatum produced the highest values of leaf weight  ratio,  specific  leaf  area  and  leaf  area  ratio.  Individual  leaf  assessment  revealed  that  shading significantly increased the final leaf area, duration of leaf expansion and specific leaf area

Shading Effects on Growth and Partitioning of Plant Biomass in Paspalum Conjugatum Berg

Glasshouse studies were carried out to determine the effect of shading on the growth and partitioning of plant biomass in Paspalum conjugatum Berg. The invidual leaf rate expansion, final leaf are, specific leaf area, and the whole plant vegetative growth pattern, dry-matter production, leaf area as well as biomass partitioning were significantly influenced by shading. At the 75% level of shading, P. conjugatum produced the highest values of leaf weight ratio, specific leaf area and leaf area ratio. Individual leaf assessment revealed that shading significantly increased the final leaf area, duration of leaf expansion and specific leaf area

Ecology of Reservoir Park, Urban Forest of Kuching City, Sarawak: Tree Species And Soil Nutrients

TIenty five plots of 20 m x 20 m were established at both well managed park (WMP) and abandoned park (AP) of Kuching Reservoir Park for comparative study on floristic composition, biomass estimation and soil characteristics. All trees with DBH >4.5cm were enumerated and identified to species level. Total estimated above ground biomass of AP (mean - 234.95 ton/ha) was not significantly different with Wl\1P (mean ==177.64 ton/ha). Total species found in both sites were 58 species from 26 families including palms, bamboos, 12 species of ferns, five species of orchids and an ant plant were recorded from both sites. They were both native or indigenous and exotic or introduced plants such as commercial timber, protected, wild and cultivated fruit species. Alstonia angustifolia is the most important species in both sites due to its giant size as shown by its highest relative basal area (RD). The AP consisted of an understorey of small trees as a result of abandonment. WMP had clear understorey layer as a result of regular thinning of undesired plants. The mean thickness of litterfall in AP is 2.68 cm which is significantly different from WMP 1.12 cm thick. The nutrients content such as N, P, K, Mg, Ca, Na, Zn, B, Fe and Cu are varied between both sites. Amount of N, C, P, Zn and Fe are higher in AP than WMP and vice-versa for other elements. The total leaf area index (LAI) of trees in AP is 2.01 m2/ha and 1.76 m2/ha for WMP

Decay resistance of extractive-free belian (eusideroxylon zwageri) and malagangai (potoxylon melagangai)

Belian (Eusideroxylon z.wagen) and malagangai (Potoxylon melagangai) are among the heaviest and very durable timbers ofMalaysia and Indonesia. It is well known that the natural durability of timbers is influenced by their extractives content. This study was earned out to determine the decay resistance of extractive-free E. z.wageri and P. melagangai wood. Heartwood and sapwood ofE. z.wageri and P. melagangai were cut into test blocks of 2 em x 2 em cross-section and 5 mm thickness. Extractives were extracted using Soxhlet apparatus. The four wood decay fungi used in this study were three white-rot fungi, Lentinus sajor-caju, Trametes versicolor and Pycnoporus sanguineus and one brown-rot fungus, Gloeophyllum trabeum. Wood decay was assessed based on weight loss after 12 weeks exposure in the soil block test. Test blocks exposed to P. sanguineus resulted in higher weight loss than those exposed to C. trabeum. Sapwood and heartwood of E. z.wageri showed higher decay resistance compared with P. melagangai. Extractive-free blocks had higher weight losses than the unextracted blocks. Although extraction of extractives significantly reduced decay resistance of both wood species, the extractive-free blocks could still be considered resistant. This study showed that the high resistance ofE. z.wageri and P. melagangai to decay is due to the presence of toxic extractives. However, extractives are not the sole factor contributing to decay resistance of both wood species

Radial variation of some anatomical features in Eusideroxylon zwageri and Potoxylon melagangai

An anatomical study was done on two species ofwoods, namely Belian (Eusideroxylon zwageri) dan Malagangai (Potoxylon melagangai). The objectives were to determine differences between selected anatomical characteristics of both species and their trend in relation to radial direction. Measurement were done on macerated fibers and safraninstained sections of both species. Among the properties measured were fiber length, fiber wall thickness, vessel diameter, count per square millimeter and ray height. The data were analysed using one-way ANOV A and regression analysis. One-way ANOVA showed that the fiber length and fiber wall thickness ofE. zwageri was longer and thicker than that ofP. melagangai. Fibre length of Eusideroxylon zwageri increased while ray height decreased with radial direction. Positive trend ofincreased in size with radial direction of fiber length, fiber wall thickness and vessel diameter ofP. mela~angai was observed. No significant radial trend was observed for number of vessellmm and ray height in P. melagangai. This study showed that radial trend and anatomical characteristics of both species were not similar

A new species of Amorphophallus (Araceae: Thomsonieae) from Sarawak, Borneo

Volume: 56Start Page: 153End Page: 15

A Review of the White-flowered Amorphophallus (Araceae: Thomsonieae) Species in Sarawak

Volume: 61Start Page: 249End Page: 26