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After years of unsustainable logging, dry deciduous dipterocarp forest (DDDF) has become poor in timber stocks and has been converted to industrial crops such as rubber. The objectives of this study were to assess teak (Tectona grandisL.f.) tree establishment under degraded DDDF conditions and to determine factors that influence the suitability of teak as a forest enrichment tree species. A set of 64 experimental plots of 4 900 m2each was set up and observed for 4–5 years for testing enrichment planting with teak under various combinations of two groups of factors: ecological conditions and forest status. Weighted, non-linear, multivariate regression models were used to detect key factors that influenced the suitability of teak. The results showed that at the age of 4 years the average dominant tree height (defined as 20% of the tallest trees in the experimental plot) reached 11.2, 7.8, 5.3 and 3.8 m for very good, good, average and poor suitability levels, respectively. Survival rates of planted teak from average to very good suitability levels were over 90%. Six key factors that affected the suitability of teak were waterlogging during the rainy season, altitude, stand volume of the degraded DDDF, soil type, percentage of sand and concentration of P2O5in the soil. Under the extreme ecological and environmental conditions of the DDDF, enrichment planting with teak gave promising results. [ABSTRACT FROM PUBLISHER]

In many developing countries there is a prevailing conflict between biodiversity conservation and the need for poverty alleviation. One possible solution for solving that conflict is to find ways that help poor people directly benefit from conservation activities. This approach has been tested in a wetland conservation project in Phu My village, Kien Luong District, Kien Giang Province in Vietnam. The 2,000-hectare seasonally inundated grassland, dominated by the sedge Lepironia articulata (Cyperaceae), in Phu My Village is the last of its kind remaining in the Mekong Delta. In November 2004, a new model of protected area was therefore established. Unlike other protected areas in Vietnam where resource exploitation is prohibited, this is an “open” protected area in the sense that the local Khmer ethnic minority people are still allowed to harvest Lepironia as they have been doing for hundreds of years. The project provides local people with skills training and production equipment so that they can make fine handicrafts from the Lepironia they harvest. The project also helps with marketing handicraft products to higher profitable export markets. After three years of operating, the daily income of people who participated was on average twice as much as it was before the project began. The unique remnant wetland is protected, which would otherwise have been turned into a rice cultivation area according to the previous land use planning of Kien Giang Province. [ABSTRACT FROM AUTHOR]

Abstract: Plantations released from management are vulnerable to transient oscillations until cohort dynamics are broken and the vertical and horizontal structures of the plantation are transformed to those of more natural forests. Cohort-desynchronizing factors such as canopy disturbances are expected to accelerate this process. Using well-established mangrove plantations in Can Gio (Viet Nam) as an example, we tested whether lightning gaps can affect transition dynamics of plantations to more natural forests by damping the amplitude or by shortening the period of oscillations in tree densities. This was done by applying point pattern analyses to remotely sensed data, and by further combining statistical and individual-based modelling. The occurrence of lightning gaps was biased by the forest matrix, which presented a challenge for the point pattern analysis. This problem was solved by using the scattered forest area as a binary mask. A Matern cluster process model was found to be suitable for describing the lightning regime. This statistical model was incorporated into the individual-based mangrove model KiWi, and simulation experiments revealed that: (i) the evenly spaced distribution of the tree cohorts in the plantation supports non-linear transition behaviour, i.e. oscillation of tree density, and (ii) the lightning regime in Can Gio damps the oscillation amplitude but is not sufficient to prevent the latter nor to decrease the length of the period of oscillations. [Copyright &y& Elsevier]