International Journal of Botany - Current Issue

Soil Seed Bank and Seedlings Bank Composition and Diversity of Wondo Genet Moist Afromontane Forest South Central Ethiopia

19 June, 2013

Wondo Genet Afromontane forest is one of the few remnant forests in the country. However, it is experiencing deforestation and fragmentation that limits restoration possibilities. The soil seed were studied to better understand the potential contribution of the soil seed and seedling banks to the natural regeneration and generate information that would assist in selecting appropriate rehabilitation and restoration activities. A total of 75 (20x20 m) quadrats were sampled. Diameter at breast height ≥2 cm and stem height ≥2 m were measured for all woody species encountered and the number of seedlings and saplings were counted. Elevation, slope and aspect were also recorded. At the center of each quadrat, a 10x10 cm plot was marked and three separate soil layers were collected and incubated in a glasshouse for 12 months. Data was analyzed using a combination of analytical methods, such as descriptive statistics, correlation of environmental variables with seedling density using R-Software and ordination techniques using software for Multivariate Analysis of Ecological Data (PC-ORD). A total of 72 woody species from standing vegetation and 60 plant species from incubated soil seed bank were identified. Seedling and sapling density of 1,330 and 917 ha^-1, respectively, were recorded. While seedling density was positively correlated with tree density (r = 0.4248, p<0.001), a negative relationship was observed with elevation (r = -0.3772, p<0.001). Elevation explained 51.21% and slope 24.4% of the variation in regeneration abundance. Wondo Genet forest exhibits a deficiency of seedling and soil seed bank warranting assisted regeneration and reduction of anthropogenic disturbances to allow natural regeneration.

Characterization of Riparian Plant Community in Lowland Forest of Peninsular Malaysia

19 June, 2013

A riparian zone is the land adjacent to streams and rivers, known to be one of the most important habitats in the tropical forest. However, not many studies have been done in Peninsular Malaysia and no information particularly in lowland forest. The purpose of this study was to characterize the plant communities where two sites were chosen, Pasoh Forest Reserve (PFR) which includes two logged-over forests of compartments (Compt.) 47 and 55 and virgin reserve of Compt. 55. The second site was in Ayer Hitam Forest Reserve (AHFR) consists of regenerating forest of Compt. 15, Compt. 14 and Compt. 13, that had been last logged in 1970 ’s. Five pairs of 10x5 m plots were then built along the riparian area for each compartment and all plants were enumerated. Results showed that a total of 2579 individuals which represents 369 species, 213 genera and 80 families were found. Generally, riparian zones of lowland forest still dominated by Dipterocarpaceae, an important timber group in tropical forest PFR recorded a higher number of diversity (Fisher Alpha) and numbers of individual compared to AHFR. Composition of plants in PFR and AHFR were found not similar with only 46 species from 31 families were shared and analysis using Bray-Curtis Similarity coefficient, BCjk and Unweighted Pair Group Method with Arithmetic Mean (UPGMA), confirmed this differences. Results also found that water-loving species only comprise of 7.8 and 9.3% from the total number of species in PFR and AHFR, respectively. This study shows that riparian area in lowland forest of the Peninsular Malaysia is site-specific due to anthropogenic disturbance and logging history.

Metal Effects on Carotenoid Content of Cyanobacteria

19 June, 2013

Cyanobacteria exhibit an extraordinary resistance to many environmental factors including metal pollution. The present study was conducted to explore the possibility of using cyanobacteria for bioremediation of Co²⁺ and Zn²⁺ as essential nutrient elements for the growth of cyanobacteria which detoxify these metals. Anabaena oryzae and Tolypothrix tenuis cells collected from paddy fields expressed different degrees of tolerance to metal(s) stress due to cobalt, zinc, copper and mercury. The tolerance of these species under different concentrations (1, 10 and 100 ppm) of heavy metals was determined. Observations were made on every 2nd day for the period of 12 days. Among the organisms studied, T. tenuis was more sensitive to the metals than A. oryzae. Copper at 1 ppm on the 8th day gave maximum carotenoid content (6.652 μg mL^-1) in A. oryzae. The mercury treated cells showed lethality at (1, 10 and 100 ppm). There was gradual increase of carotenoid content after 12 days, especially at (1 and 10 ppm) of Co²⁺ and Zn²⁺ in A. oryzae. This indicated the possibility of application of this species for detoxification of effluents.