The main purpose of this paper is to clarify the similarities and differences in agricultural practices among the Iban people who live in geographically adjacent areas but different countries, Malaysia and Indonesia. The research areas are Lubok Antu in Sarawak, Malaysia and Lanjak in West Kalimantan, Indonesia. As the Iban people in these areas are of the same ethnicity, their traditional ways of shifting cultivation have been similar. However, at present, the two areas differ considerably in farming area, rice yield and application of fertilizers and agrochemicals. This may be partly due to intensification of agricultural practices and the resulting decline in soil fertility, but is largely due to economic disparities between the two areas. The effects of economic and political factors are analyzed and insights gained by the investigation of additional agricultural and economic activities such as cash crop production, wage-earning jobs and family expenditures in the research areas.

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The Bemba people, slash-and-burn cultivators in northern Zambia, practice the citemene system, which is distinguished by two characteristics: first, men climb up tree trunks larger than 15 cm diameter at breast height and lop off the branches, leaving the trunks standing; second, women carry the branches from the tree-cutting area and pile them up to waist-height in a central area where the garden is to be cultivated after burning. The woodland preference of Bemba people for opening citemene fields is related to the woody biomass they can acquire there, which serves to fertilize the soil. Based on the interviews from Bemba people, their woodland preference for opening citemene fields fell into four categories: woodlands (1) highly suitable for the establishment of citemene fields, (2) suitable to serve as citemene fields, (3) suitable to serve as small fields of kakumba, and (4) unsuitable as either type of field. As a result of vegetation research in 40 plots (50 m × 50 m), they estimated woodlands with more than 90 t ⁄ ha woody biomass in fresh weight (FB) “highly suitable for creating gardens”. In fields of that size, high yields of finger millet could be expected. They estimated that woodlands with FB between 60 and 90 t ⁄ ha are potentially “suitable woodland as citemene fields”. In woodlands ranging from 30 to 60 t ⁄ ha FB, they reduced the size of the burned field, called kakumba. They classified woodland of less than 30 t ⁄ ha FB as ”unsuitable for use in growing crops“. Bemba consider it very important to cut and pile sufficient quantities of branches for burning the soil thoroughly, in order to nourish the soil.

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Joint Forest Management was introduced as an innovative method to realize sustainable forest utilization in India. Since the central government issued the first Joint Forest Management guideline in 1990, it has been accepted by the state governments and also supported by local communities. In the state of Kerala, 28.9 % of the land is maintained as forests, despite a high population density. Research on the livelihoods of local people and the role of Participatory Forest Management (Joint Forest Management in Kerala), is expected to benefit other regions with similar conditions. Since information on the forests in Kerala is not sufficient, firstly we outlined the Participatory Forest Management programs and the implementation process, and secondly selected a program and conducted in-depth interviews of 40 households. The results of this study indicate that the guidelines of the central government were duly modified to meet the local conditions. The local stakeholders were well organized to implement Participatory Forest Management. Rehabilitation activities were completed smoothly at the initial stage, but after that the process was stalled. Pressures on forest resources were originally not so serious and agroforestry on farmlands is common so it seems difficult to maintain the activities and enthusiasm of the participants. As a result, incorporating some measures for local communities to an earn income through forest management is recommended. Using non-forest land tree crops for firewood is another alternative solution to forest issues.

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To evaluate the effects of forest disturbances on flying insects, samples were taken at three selected disturbed sites in a mountainous area in Trawas, East Java. Changes in the abundance, family richness and composition of flying insects were monitored during the 2003 wet season and 2004 dry season using window traps. A total of 4947 individuals of insects, representing 82 families, were collected. The overall abundance and family richness of flying insects declined with increasing site disturbance. Community composition was also remarkably different among the sites. Herbivorous insects, such as Chrysomelidae and Orthoptera, and scavenging beetles, such as Scolytidae and Nitidulidae, were the most sensitive to disturbance. In contrast, some agricultural insects were found in highly-disturbed site. These results indicate that forest disturbances change flying insect composition.

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Seed dispersal by animals plays a crucial role in the tropics. Fruit-bearing plants serve not only as nutritional sources for frugivores, but also as seed sources for forest regeneration and as important foci for the re-establishment of other plant species by attracting seed-dispersing frugivores to their vicinity. However, opportunities for investigating the interactions between a diverse fruit flora and disperser fauna are rapidly disappearing in Southeast Asia. We observed the behaviors of 28 species of frugivorous visitors to 15 fruit-bearing plant species in a moist evergreen forest in Khao Yai National Park, Thailand, to determine their potential quality as seed dispersers. Behavioral observations included the frequency and duration of visits by each forager and their fruit-handling techniques. The highest numbers of frugivores were recorded at strangler figs, confirming their role as an important resource for frugivores at Khao Yai. Mammals and non-passerine birds spent significantly more time at food plants than did passerine birds. Our study provides a preliminary inventory of plant-frugivore interactions that is comparable to other study sites in Southeast Asia. Since fruit-frugivore interactions may differ among the forests, these kinds of studies need to be replicated at faunally intact forests, as well as depleted forests, in Southeast Asia.

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Of the 129 indigenous Acacia species in Africa, 43 species have been confirmed to exist in Kenya. The objective of this study was to investigate Acacia species vegetation in Kenya and to analyze the relationship between the distribution of Acacia species and their growth environments. In this survey, two areas were targeted, representing, as expected, a great variety of plant vegetation. The first area extended from the foot (altitude 2745 m) of Mt. Elgon to the Mombassa coast (1 m), separated by 925 km, and the second extended from the foot (2150 m) of Mt. Kenya to Lake Magadi (620 m), separated by 511 km. Two methods of ecological analysis, regression and ordination analysis, were used to investigate how Acacia species abundance and composition are affected by environmental variables. Of the total 6492 Acacia trees, more than 50 % were Acacia tortilis, Acacia melifera, Acacia nilotica and Acacia seyal var seyal. Regression analysis provides evidence that altitude explains patterns in the abundance of Acacia species. Other environmental variables explained significant amounts of deviance for some, but not all, Acacia species. Ordination analysis and regression analysis suggest that sites with Acacia lahai, Acacia hockii and Acacia abyssinica are generally of higher altitude, contain Croton megalocarpus and Ficus species and are on hillsides. It also suggests that sites with Acacia tortilis and Acacia mellifera occur at lower altitudes; contain Terminalia brownii, Boscia angustifolia, Combretum species and Adansonia digitata; and have salty soil and are in a valley. Each individual Acacia species has a specific ecological characteristic and survival strategy. For example, Acacia tortilis trees have a comparatively high environmental adaptability and competition capability. A. xanthophoria and A. drepanolobium's important survival strategy is their speedy rate of growth.

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Leaf litter production and its seasonal patterns were estimated by installing 60 litter traps in the moist deciduous forests of Madiun Forest District in Eastern Java at six selected teak (Tectona grandis) plantations (10 to 40 years old). Ten litter traps each with a quadrat top of 1 m² in size were randomly placed within each stand, and the leaf litter was collected every 2 weeks over a 12-month period from October 2000 to September 2001. Total annual leaf litter production of various stand ages in the study sites ranged from 4.48 to 5.79 Mg ha^-1 yr^-1, of which 60 % of the leaves fall during the dry season (June-September). Neither structural attributes of vegetation, such as stand age, density and basal area, nor altitude, directly influenced the total annual leaf litter production.
Leaf litter fall followed a monomodal distribution pattern with the peak occurring in June (early dry season) for 10, 15 and 20-year-old teak plantations. However, the 25, 30 and 40-year-old teak plantations had bimodal distribution, with the two peaks occurring in June and September (later dry season). The variation in the seasonal patterns of leaf litter is considered to be partly attributed to the growth behavior of the trees through adaptations to soil water stress during the dry season under tropical climatic conditions in the area.

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We estimated the trunk volume, aboveground and belowground biomasses, and carbon stock in the soil of 17- and 22-year-old teak (Tectona grandis L.f.) stands in northern Thailand. Allometric equations for estimating the trunk volume and biomass of each organ, based on five sample trees in each stand, gave high accuracy (r² = 0.881 to 1.000). The trunk volumes of the two stands were 116.9 and 139.6 m³ ha^-1, respectively. The total aboveground and belowground biomasses of the trees were 89.3 and 98.8 Mg ha^-1, respectively. The ratio of below- to above-ground biomass was 25.6 % in the 17-year-old stand and 20.0 % in the 22-year-old stand. The mean annual increment (MAI) of the trunk volume and the total biomass of the trees were 6.9 and 6.3 m3 ha^-1 yr^-1, and 5.3 and 4.5 Mg ha^-1 yr^-1, respectively. The average carbon stock in the soil was 211.4 MgC ha^-1 (range: 153.2 to 251.8 MgC ha^-1) in the 17-year-old stand and 137.2 MgC ha^-1 (range: 122.7 to 157.9 MgC ha^-1) in the 22-year-old stand. These values are about three times larger than the carbon stock of the trees themselves (44.6 and 49.4 MgC ha^-1; assuming 50 % carbon content of tree biomass). These results highlight the importance of estimating the belowground carbon pool.

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The two tested soils were poor in nitrogen, phosphorous, potassium, magnesium and sulphur. Application of potassium, magnesium and sulphur, increased the sugarcane yield significantly. Treatments with potassium, magnesium and sulphur fertilizer increased sucrose content markedly. Increased use of potassium, magnesium and sulphur fertilizer increased sugarcane’s fiber content.
The biomass production is 80-140 tons per hectare. Sugarcane growth is divided into four stages: seedling, tiller, stretching, and mature. Sugarcane grows quickly during tillering and stretching periods, also during these stages sugarcane biomass production is greater and more minerals are absorbed, especially potassium, than at other stages. In every development stage of sugarcane, the potassium content of a sugarcane plant is higher than other nutrient elements, except for nitrogen. Generally, sugarcane yield is 45000-60000 kg per hectare. The absorbable potassium (K₂O) amount of sugarcane was 109.1-315.28 kg per hectare.
According to the statistical results of 82 field experiments in Nanning and Laibin, sugarcane yield and the amount of potassium sugarcane absorbed was significantly and positively correlated. The correlation coefficient was r = 0.979^**. The function of the sugarcane yield (y) with the amount of potassium sugarcane absorbs (x) was y = 31687.1 + 246.0x.

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