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

A Study on Pollen Viability of Piper colubrinum Link

Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme for Phytophthora to foot rot resistance in the cultivated species, P. nigrum. This project was carried out to reveal the optimum time to collect pollen of P. colubrinum for artificial pollination. Through this study, anther dehiscence was proved occurred around 9 am. Based on the result obtained from study on the time of anther dehiscence, the pollen was classified into five stages for testing on the viability, i.e., stage 1, before anther dehiscence, i.e., around 7 am (pollen obtained by crushing on the anther); stage 2: immediately after anther dehiscence, i.e., around 9 am; stage 3: two hours after anther dehiscence, i.e., around 11 am; stage 4: four hours after anther dehiscence, i.e., around 1 pm; and stage 5: six hours after anther dehiscence, i.e., around 3 pm. Data obtained from pollen germination and pollen tube growth study showed that pollen of P. colubrinum was the most viable at two hours after anther dehiscence and onward. It was also proved that the viability can be maintained up to at least eight hours. Pollen obtained before anther dehiscence by crushing on the anther was found less viable with lower percentage of pollen germination and retarded pollen tube growth. In other words, the experiment enlightened that artificial pollination between P. nigrum L. and P. colubrinum Link was ideally to be carried out approximately starting from 11 am until 5 pm, considering the viability of pollen of P. colubrinum