Various symbioses from facultative relationships to obligate mutualisms exist between the epiphytic myrmecophytes in 5 genera of Hydnophytinae (Rubiaceae) and the associated ants. However, the phylogenetic relationships and evolutionary processes have not been studied well. In the present study, a molecular phylogenetic relationship based on the DNA sequence of the atpB-rbcL intergene region was analyzed in 6 species of 4 genera in Hydnophytinae. The inferred phylogenetic relationship was shown as (Myrmecodia spp. + (Myrmephytum + (Anthorrhiza + Hydnophyfum spp.))). It was suggested that the ancestral taxon of Hydnophytinae was Myrmecodia or Myrmephytum because these genera were settled in the basal position in Hydnophytinae used in the present study. In addition, we discuss the evolution of diverse symbioses of Hydnophytinae based on the inferred phylogenetic relationships, together with ecological and geographical information. It is possible that the ancestor evolved as an epiphyte which lived in the nutrient-poor habitat of Southeast Asia and had a specialization for efficient and relatively obligate mutualism with ants by increasing their complex cavities as ant nesting spaces. After Myrmephytum and Anthorrhiza were respectively evolved in the Philippines and Papua New Guinea, the ancestor of Hydnophyfum evolved as a xeromorphic tuberous epiphyte in the dry environments of Southeast Asia and acquired facultative symbioses with arboreal ants.

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Measurements of photosynthesis (A) and stomatal conductance (g_s) were conducted using the leaves of four tropical tree species (Dipterocarpus sublamellatus, Neobalanocarpus heimii, Ptychopyxis caput-medusae, and Xanthophyllum amoneum) in the canopy of the lowland forest at the Pasoh Forest Reserve in peninsular Malaysia. A canopy walkway was used to reach the canopy of 30- to 40-m-tall trees and diurnal changes in A and g_s were determined. The diurnal patterns for A differed between days and between species, though A of the four species were similar but quite low. In general, A increased with increasing photosynthetically active radiation (PAR) before noon, then declined. As well, a linear relationship was detected between g_s and A, but no statistically significant correlation could be confirmed between these two factors for D. sublamellatus and P. caput-medusae in November and July. The value of gs decreased with increasing vapor pressure deficit for D. sublamellatus, but the other species did not show this response.

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Biomass changes in secondary succession on a large-scale shifting cultivation area, northeast Borneo Island were studied. The area around the study sites has been rapidly developed and primary forests were cleared on a large scale. Life form composition rapidly changed in this study sites: i.e., from weedy forb community (four-month and one-year-old), to grassland with sparse canopy trees (three-year-old) and further to forest community (ten-year-old). Pioneer trees (eg. Trema orientalis) reached to 6.5 cm dbh and 4.4 m high in three-year-old, and further to 15.5 cm dbh and 13.0 m high in ten-year-old. Correspond to these rapid successional changes, above-ground biomass linearly increased with age: namely 237 g m^-2 (four-month), 650 g m^-2 (one-year), 1573 g m^-2 (three-year) and to 3463 g m^-2 (ten-year). In comparison with the other studies of the biomass accumulation in tropical fallow, biomass increment in the ten-year-old stand was small. The adverse effect on biomass accumulation can probably be ascribed to limit the growth and/or invasion of primary forest tree species due to the severe artificial disturbance around the area. Moreover, the number of pioneer tree species might be low in the study sites, where are transition area from lowland forest to lower montane forest.

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As a part of efforts to effectively utilize inland valleys of Ghana for sustainable agricultural production while also protecting and conserving the environment, the bio-physical nature of a benchmark site in a semi-deciduous forest zone was characterized using the integrated transect method. Different valley types, first-, second-, and third-order inland valleys, were identified within the valley system. The main soil types identified were Ferric Lixisol, Ferric Luvisol and Haplic Gleysol in the upland, fringe and valley bottoms, respectively. The soil reactions for both the upland and lowland soils were slightly acid (pH 4.8-5.9) in the topsoil to strongly acid (pH 4.0-4.3) in the subsoils. Available P (Bray 1) was lower in the upland and lowland soils. Effective cation exchange capacity (ECEC) and levels of exchangeable Ca, Mg, and K were higher for the valley bottom soils than the upland soils. The total nitrogen levels of both upland and lowland soils, however, were higher in the topsoils but lower in the subsoils (0.84- 0.02%). Generally, the soil fertility status of the lowland soils was slightly higher than the fertility status in the uplands. The upland soils were well drained, while the valley bottom soils were poorly drained. The water table exhibited a cyclical movement of surfacing in the rainy season and going into a trough in the dry season. The valley bottoms are used mainly for cultivating rice in the wet season and vegetables in the dry season, while the uplands are used mainly for cereals, root and tubers, and plantation crops. The percentage of the land overall covered by primary and secondary forest was estimated to be less than 20%. The main identified constraints on the utilization of the inland valley watersheds are soil degradation in the uplands and water control and soil fertility maintenance in the valley bottoms.

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The contribution of the sawah system (bunding, leveling, and puddled fields to irrigate rice cultivation) was studied alongside the traditional slash-and-burn, rain-fed lowland rice farming system in the inland valley bottom of the Ashanti region, a semi-deciduous forest zone in Ghana. Different organic and inorganic fertilizers were tested under the different systems. The results revealed that the sawah system resulted in a greater number of productive tillers, higher straw production, and higher grain yield compared to the farmers’ rain-fed lowland practice.
Among the fertilizer treatments, the poultry manure, relatively rich in both N (nitrogen) and P (phosphorous), and the use of the inorganic fertilizers N 90, P₂O₅ 60, and K₂O 60 kg ha^-1 at the recommended rate for rice exerted similar effects on grain yield under both systems This means the soils were relatively deficient in available N and P. The sawah system had a remarkable effect on N uptake by rice grain and straw in the inland valley bottom. Agronomic uptake N efficiencies and agronomic N efficiencies of fertilized N in both mineral and organic forms were considerably higher under the sawah system in the valley bottom. The present rain-fed lowland condition of local farms in the inland valley bottoms of the Ashanti region of Ghana showed very poor efficiency in the use of fertilized N in both the mineral and organic forms. Our study results indicate that use of the sawah system is a prerequisite for the efficient use of fertilizer to increase rice yield in the inland valley bottom.

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Fire has become a great threat to Indonesian rainforest. However, informative data quantifying the effects of wildfire on the soils are still limited. We have been studying the leftover effect of forest fire on characteristics of Indonesian Ultisols. Current experiment evaluated physico-chemical characteristics of soils under different ecosystems with different wildfire history. Seven sites, which could be grouped into unburnt sites (conservation forest (CF), Pine forest (iF), Acacia mangium plantation (AM), and home garden (HG)) and burnt sites (Acacia mangilan plantations bumt in i995,L997, and 1998) referred as AM-b95, AM-b97, and AM-b98, respectively, were sampled. Organic layer was found in CR PR and AM but not in any other sites. Morphologically, soils of unbunt sites had darker A horizon than those of burnt sites. In spite of lack of significant differences, bulk density decreased with increasing period after fire, indicating the recovery process. Although the upper layer of the bunt soils was physically harder than that of the unbumt soils, soil hardness did not appear to be a limiting factor for plant growth. Soil in the unbumt sites was chemically more acid but contained more organic C and N than that in the burnt sites. Surface soil of PF, AM-b98, and HG had much higher exchangeable Ca than any other sites. However the CEC was low across the study sites, irrespective of the high clay content. Available P was also low, and correlated with high Al solubility. Crysialline Al, Si, and Fe contents of all soils were higher than amorphous Al, Si, and Fe oxides. ZpC values were low across the study sites. However, higher negative charge generated by organic matter had resulted in lower ZPC values at the surface layer as compared with the subsurface layer. Although soils in the unbumt sites showed a better physico-chemical potential than the bunt site, in general Ultisols in the study sites had undergone strong weathering and showed low natural fertility potential.

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The color choice behavior of the tsetse fly with odor bait and without odor bait was investigated in the field in Ngruman, Kenya. Traps were made using a mixture of blue and green pigments in different ratios and then checked for their trapping efficiency. The effects of color in trapping without odor bait was the same as previous reports, i.e. more flies are attracted by blue compared with other colors. Trapping efficiency was generally augmented when odor bait was used. However, trapping efficiency decreased when odor was presented with a pure blue cloth and increased at the blue-green cloth. It is concluded that blue-green cloth is the most useful material from which to make traps in order to control the tsetse fly, and thereby the incidence of sleeping sickness.

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In this paper I will discuss variation in holothurian resource exploitation in the Philippines generally and trepang fishing especially on Mangsee Island, in the southern part of Palawan Province, where people fish in the Spratly Islands. Holothruian has been a major exporting product from maritime Southeast Asia to China for, at least, three hundred years. Many scholars working in Southeast Asian maritime societies have noted the dynamic human networks involved in pursuing dried sea products like trepang or shark fins. However, few scholars have dealt with the actual materials of the trade. This paper will establish that 22 species of holothurian are traded in the Philippines at present, and that the price of the most expensive is some 80 times greater than that of the cheapest. Moreover, in recent years, lower quality trepang has been acquiring more commercial value. Holothurian is not just an exclusive expensive foodstuff as mentioned in historical records. It is also an ordinary material used in the present. The cheaper trepang species are consumed more than ever before in the Philippines and elsewhere. One of the most important aspects of the Philippine trade is that the country exports a huge volume of trepang of lower commercial value. There is a vast difference in the industry in the past and the present and we have to pay careful attention to the continuity and discontinuity in the industry.

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The deforestation issues often rise in conjunction with the forest existence awareness and forest ecology considerations. The objective of this paper is to identify the sources of deforestation issues related to the Indonesian forest industry demand for raw material in the future. Research result shows that the main sources of deforestation issues in Indonesia are resettlement program in transmigration, shifting cultivation activities, forest fire, and forest extraction. In the year 2000, quantity demand for raw material will be higher than the capability of forest to supply. Furthermore, all conversion forest area will be lost in the year 2005 if assumed that the conversion and deforestation activities will be done in the conversion forest areas. The important policies suggestive of improving the situation are: (1) increasing replanting program to balance the deforestation, (2) strengthen regulation and forest security in order to control deforestation activities, and (3) correcting the forest management with consideration in sustainable forest management.

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