Leaf-litter decomposition was examined from November 2008 to October 2009 using litter bags in a secondary mangrove forest along the Trat River, eastern Thailand. The study site exhibited three distinct vegetation zones (dominated by Avicennia, Rhizophora, and Xylocarpus spp.) moving inland from the river edge. The decomposition rates (K), indicated by a negative exponential curve, were numerically ranked with the highest, Avicennia (0.023), at the river edge and decreasing as heading inland through the Rhizophora (0.020) zone to the lowest decomposition rate at the most inland Xylocarpus zone (0.014). They were similar to previously reported values for mangrove forests. The amount of residual leaf litter in the Avicennia and Rhizophora zones decreased rapidly during the first 112 days of the trial, whereas that in the Xylocarpus zone decreased more slowly. Over the remainder of the trial period (total of 362 days), residual leaf litter slowly declined. At the end of the trial, the weight of leaf litter lost was highest in the Avicennia zone, followed by the Xylocarpus and Rhizophora zones. Correspondingly, the C/N ratio of the residual leaf litter decreased rapidly over the first 54 days of exposure time in all three zones, and then stabilized to a slow change after 112 days of exposure onwards. Differences in the amount of leaf litter lost were discussed in terms of causative physical factors such as inundation period and soil temperature. The soil temperature at a depth of 10 cm below the surface was highest in the Avicennia zone and decreased with increasing distance from the river edge. The relative elevation of the forest floor in the Avicennia zone at the river edge resulted in the longest period of inundation, which, along with high soil temperature, promoted the decomposition of leaf litter. Additionally, we mentioned the contribution of CO₂ released from litter decomposition through soil respiration of the mangrove forest.

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The hypothesis that the fruiting phenology of a plant community is affected by both fluctuating predation pressure and the seed preference of predators (risk of predation) was tested in a tropical peat swamp forest in Central Kalimantan, Indonesia. We conducted: (i) a seed removal experiment using model seeds (i.e. jackfruit seeds which are low in secondary compounds and attractive to seed predators) that investigated fluctuations in predators’ activity and (ii) a seed removal experiment using 17 natural species to clarify seed preferences of seed predators; we also monitored the fruiting phenology of the 17 study species. The removal rate of model seeds decreased during high water table, whilst it increased during low water table, indicating that flooding restricted the feeding activity of terrestrial small mammals which are the dominant seed predators in peat swamp forest. Differences in fruiting time between species with higher removal rates (preferred) and lower removal rates (less preferred) were observed. Species with high removal rates showed peaks of fruiting during flood periods and the reproductive pattern of this group was negatively regressed to the removal rate of model seeds and positively regressed to water level. The implication of this result is that these tree species produce seeds and deposit them on the ground whilst seed predators are disturbed by flooding, thus they avoid seed deposition when predators’ activity is high. Seed production amongst species with low removal rates was variable indicating that these tree species are likely more adapted to other factors that affect survival of seeds and/or seedling (i.e. regeneration niche) than predation. We were able to demonstrate another relationship between fruiting phenology and seed predation that differs from that of mast fruiting. The fact that species with preferred seeds produce their fruits when predator activity is restricted might have developed under the conditions of poor nutrient availability and frequent flooding that are characteristic of the peat swamp forest ecosystem.

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The purpose of this article is to clarify the Shipibo’s distribution of bananas, and to consider the current situation regarding the importance of “aquinquin (sharing)” in their society. The Shipibo people practice food distribution as a custom. While bananas are the major staple food that is eaten most frequently, most households do not supply their own needs. They acquire and exchange bananas in various ways: they get the fruit through requests, as gifts, in requital/exchange, and through purchase in the settlement, as well as through requests to harvest made by the “have-nots” or the gift of harvesting permission by the “haves,” both of which are made through face-to-face communication, as well as distribution without tacit permission or formal notification by field owners. While the Shipibo people consider “sharing” to be important and expect male villagers to produce bananas by themselves, banana distribution has been practiced in a circle that includes “chiquish (lazy)” people who do not have their own banana fields. However, “lazy” people were recently excluded from this circle because of their lack of “shinna (care for others).” The Shipibo people have continued banana distribution with a core notion of “aquinquin,” but it is not an essentialistic and stable custom, rather is the dynamic process of rearrangement for day-to-day as villagers sound out each other’s acceptable situations in their daily life.

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