Variation in wood fibre traits among eight populations of Dipterocarpus indicus in Western Ghats, India

Wood elements and anatomical ratio of Dipterocarpus indicus were studied to evaluate variation among populations and to recommend for end selection. The variation of wood element [fibre length (FL), fibre diameter (FD), lumen diameter (LD), cell wall thickness (CWT), double wall thickness (DWT), and lumen volume (LV)] and anatomical ratio [fibre lumen area (FLA), slenderness ratio (SR) and runkel ratio (RR)] were investigated in a girth class of 100- 120 cm among eight populations of Dipterocarpus indicus in Western Ghats, India. The study revealed a significant variations in FL (0.2426), FD (4.7019), LD (3.1689), CWT (2.7104), DWT and (5.4298) among populations. The variations in anatomical ratios were significant among populations except in case of LV. The causes of variations among populations in their wood traits were attributed to the site factors. The interaction between genetic makeup of wood traits combined with effects of edaphic, local and regional climatic conditions reflect the amount of variation among populations. The highest coefficient of variation (CV %) for FL, FD, CWT and DWT was recorded in population of Gundya whereas low coefficient of variation were recorded in the population of Makuta (FL), Devimane (FD, CWT and DWT), and Sampaje (LD). The wood of Dipterocarpus indicus was found undesirable for pulp wood but can be utilized for plywood timbers

Floristic diversity of regenerated tree species in Dipterocarp forests in Western Ghats of Karnataka, India

The research was focused on exploring the structure, diversity and form of regeneration process of the Dipterocarp forests in Western Ghats in relation to environmental factors. Eight populations in the distribution range of Dipterocarp forests were selected. In each population 32 plots of 2m×2m were laid down randomly. A total of 1243 seedlings < 10 cm dbh (diameter at breast height) belonging to 99 species and 48 families were recorded. The number of regenerated tree species was found to be high in the populations of Mudigere (40), Sakleshpura (40) and Makuta (39), which are characterized by favorable locality factors and lower disturbances. The highest similarity index in species composition was recorded between the populations of Sampaje in Kodagu district and Gundya in Dakshina Kannada (60%) whereas the lowest similarity index was observed between the population of Sringeri in Chikmagalore and Sampaje (53%) and Gundya and Makuta (35%) in Kodagu district. Dipterocarpus indicus was found to be dominant among the regenerated tree species in all the sites studied except Gundy and Sampaje. The frequencies of regeneration classes (seedlings, saplings, poles and adult trees) were shaped as inverse J curve indicating the normal regeneration pattern under the present disturbance. The average disturbance of litter collection, grazing, fire, weeds and canopy opening were significant among different populations (p<0.05). Negative correlation was observed between disturbance and species richness, number of individuals and density

Main vegetation types and plant species diversity along an altitudinal gradient of Al Baha region, Saudi Arabia

Plant species composition patterns and vegetation types were investigated along Elevational Gradients in Al Baha region, Saudi Arabia. Sandy plain, wadis, drainage lines, rocky outcrops, hills and fallow lands occur over a wide geographic range encompassing variation in plant species and communities among these different ecological sites. To provide a quantitatively based classification of the vegetation we used Multi Variant Statistical Package (MVSP) software, followed by the re-arrangement of a matrix of the similar plant species in rows and similar sample sites in columns. Plant density and environmental variables were measured and recorded in each quadrat. Two-way indicator species analysis and Canonical Correspondence Analysis (CCA) were used to analyze the relationships between vegetation and environmental variables, while Arc Map was used to analyze the pattern of plant species density. A total of 59 sample plots (25 × 25 m), stratified, randomly-placed relevés were collected in Al Baha region, along a cross section running from south-west to north-west. About 190 plant species belonging to 59 families were recognized. This study showed that these plant species formed 15 vegetation types that primarily correspond mainly to different combinations of elevation, and topography. The study concluded that this research has provided the first quantitative and systematic survey of the vegetation in Al Baha region. Keywords: Vegetation types, Al Baha, Saudi Arabia, MVSP, Plant densit

Impact of anthropogenic pressures on forest structure and species composition of moist deciduous forest in thithimathi range of Western Ghats, India

The present investigation involves studying the impact of human interference on species composition, forest structure and regeneration pattern in moist deciduous forest. Six study areas that are proximal and distant to the settlements (hamlets) in the buffer zone were selected. Anthropogenic pressure is a common phenomenon in the developing countries where the population growth rate is high. The results revealed that the species richness, Shannon’s diversity index, basal area and density were less in the areas close to the settlements compared to the areas away from the settlements. The average value index (AVI) was adopted and the disturbance parameters were classified into major, moderate and minor categories having the AVI value ≥ 1.55, 1 to 1.54 and ≤1 respectively. Lopping, cut stumps, grazing, litter collection, soil removal, domestic animal’s dung and canopy opening showed significant variation between first transect and the last transect. Cumulative disturbance index (CDI) and the regeneration density of population showed a negative correlation. Increased value of CDI has shown a decreased regeneration status of tree species (R2 = 0.775). The trend line showed higher density of regenerating individuals in low and medium level of CDI and decreased drastically with increasing in CDI. The total number of regenerated seedlings in first transects was low and increased in the last transects away from the settlements. Student t-test showed significant differences between the proximal areas (1.154 ± 0.368 seedlings per 0.04 ha) and the distant areas (1.875 ± 1.178 seedlings per 0.04 ha) of settlements at p= 0.0002. Keywords: Anthropogenic disturbance, Forest structure, Species composition, Regeneration, Western Ghats of Indi