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Aim of the study: The major objective of this study was to estimate the biomass increment and carbon (C) storage of the main ecosystem components in an age-sequence of three Acacia mangium plantation stands.Area of study: Chang Riec Historical - Cultural Forest, Southeastern region, Vietnam.Material and methods: In order to assess the biomass of different tree components, 36 trees with diameter at breast height ranging from 13.38 to 22.87 cm were harvested from the different aged stands. Biomasses of understory (shrubs and herbs), and litter were also determined. Carbon storage in the trees and understory biomass, litter, and mineral soil (0-50 cm) were determined by analyzing the C content of each compartment.Main results: The biomass in trees, understory vegetation, litter, and ecosystem increased with stand age. Soil C represented 61.99% of the total, aboveground tree biomass C made up 26.73%, belowground tree biomass C accounted for 7.01%, and litter comprised 2.96%, whereas only a small amount (1.30%) was associated with understory vegetation. The average C content of total tree (47.97%) was higher than those of understory and litter. Soil organic C stock in the top 50 cm depth in 4-, 7- and 11-year-old stands of A. mangium were 86.86, 126.88 and 140.94 Mg. C ha-1 respectively. Soil C concentration decreased continually with increasing soil depth. Total C storage of three planted forests ranged from 131.36 to 255.86 Mg. C ha-1, of which 56.09 - 67.61% of C storage was in the soil and 26.88 - 40.40% in the trees.Research highlights: These results suggest that A. mangium is a promising afforestation tree species with fast growing, high biomass accumulation and high C sequestration potential.Keywords: Acacia mangium plantations; Biomass; Ecosystem carbon storage; Age-sequence; Vietnam.

Aframomum species (Aframomum danielli, Aframomum melegueta and Aframomum sceptrum) are used traditionally as medicine and food preservatives. Synthetic preservatives have been reported to be carcinogenic; hence, the continuous search for a natural preservative. This study was designed to validate the efficacy of the three named Aframomum species as a preservative against fungi that causes spoilage in raw fish and meat. The methanolic extracts of the samples were screened against Aspergillus tamarii, Aspergillus fumigatus, Aspergillus ochraceus and Trichoderma sp. using pour plate technique. The fungi were isolated from the raw fish and meat by the method of serial dilution then pour plated into Potatoes Dextro Agar (PDA) incubated at 37ºC for 7 days. The fungi observed were subcultured to get pure culture. The three samples showed significant antifungal activities against Aspergillus tamarii, Aspergillus fumigatus, Aspergillus ochraceus and Trichoderma sp. at 25%, 50% and 75% concentrations. The significant antifungal activities displayed by extract of these samples could be attributed to their phytochemical and nutritional components of the samples as well as their antioxidant activity. The three samples could be valuable natural preservatives with additional therapeutic potential.

Garcinia kola plays an important socioeconomic role in the Africa culture. Inspite of this, the plant only exists in the wild or as part of left over in the Agroforestry farms. Therefore, this research examined the phenology in seed germination for possible plantation establishment. G. kola seed dormancy and growth was investigated using hormone Napthalene Acetic Acid (NAA) and Benzene Amino Purine (BAP) application to induce quick germination and early growth The experiment was laid in a Completely Randomized Design (CRD) with seven treatments (0.5mg/ml BAP, 0.5mg/ml NAA, 1mg/ml BAP, 1mg/ml NAA, 2mg/ml BAP, 2mg/ml NAA and Control) in twenty replications. The results showed that Garcinia kola seeds germinated in seven weeks in IBA. Growth were assessed for 19wks and the result showed that Length of Radicle (LR) and Number of Radicle (NR) were significantly affected by the treatments, while 0.5mg/ml IBA gave the best result among the treatments. Length of Plumule, Number of Leaves and Collar diameter were not significantly affected by the treatments.Keywords: Garcinia kola, seed, hormone, dormancy, germination

Conducting binary-exchange experiments is a common way to identify cationic preferences of exchangeable phases in soil. Cation exchange reactions and thermodynamic studies of Pb 2+ /Ca 2+ , Cd 2+ /Ca 2+ , and Zn 2+ /Ca 2+ were carried out on three surface (0-30 cm) soil samples from Adamawa and Niger States in Nigeria using the batch method. The physicochemical properties studies of the soils showed that the soils have neutral pH values, low organic matter contents, low exchangeable bases, and low effective cation exchange capacity (mean: 3.27 cmolc kg −1 ) but relatively high base saturations (≫50%) with an average of 75.9%. The amount of cations sorbed in all cases did not exceed the soils cation exchange capacity (CEC) values, except for Pb sorption in the entisol-AD2 and alfisol-AD3, where the CEC were exceeded at high Pb loading. Calculated selectivity coefficients were greater than unity across a wide range of exchanger phase composition, indicating a preference for these cations over Ca 2+ . The eq values obtained in this work were all positive, indicating that the exchange reactions were favoured and equally feasible. These values indicated that the Ca/soil systems were readily converted to the cation/soil system. The thermodynamic parameters calculated for the exchange of these cations were generally low, but values suggest spontaneous reactions.