Vegetation Structure and Carbon Stock of Two Community Managed Shorea robusta Forests of Dhangadhi, Nepal

Community forests play a vital role in sustainable development and storing carbon stock to mitigate global warming. This study aimed to assess the plant diversity, carbon stock and regeneration status of two Shorea robusta forests managed by the community - Manehara Community Forest (MCF) and Siddhanath community forests (SCF) of Kailali district, Nepal. These two forests differ in the moisture regime- MCF is with ponds and streams and is mostly wet, but SCF is primarily dry with no ponds and streams. To examine vegetation status and carbon stock in these two forests, twenty circular plots of 20 m radius was laid in each forest using stratified random sampling. Within each main plot, two subplots of 5m radius and three subplots of 2m radius were laid to study shrub and herb characteristics, respectively. Soil sampling was also done to analyze the role of soil moisture in carbon stock and regeneration. For this, soil samples of each plot were collected up to 20cm depth. Altogether 100 plant species were recorded from the study forests. Tree and shrub diversity was higher in MCF than in SCF, but herb diversity and seedling numbers were higher in relatively dry SCF than in MCF. The carbon stock of MCF (92.99t/ha) was higher than in SCF (51.94 t/ha). In both forests, carbon stock increased with the increasing basal area (P = 0.0001). A significant strong positive relationship (P = 0.0001) between density and carbon stock was found in SCF, but this relation was weak (P = 0.018) in MCF. Both community forests were fairly regenerating with a good number of small aged individuals, SCF shows an inverted J shaped density diameter (d-d) curve, whereas MCF shows a bell-shaped d-d curve.

Characteristics and factors influencing the natural regeneration of Larix principis-rupprechtii seedlings in northern China

Larix principis-rupprechtii is an important and widely distributed species in the mountains of northern China. However, it has inefficient natural regeneration in many stands and difficulty recruiting seedlings and saplings. In this study, we selected six plots with improved naturally-regenerated L. principis-rupprechtii seedlings. A point pattern analysis (pair-correlation function) was applied to identify the spatial distribution pattern and correlation between adult trees and regenerated seedlings mapped through X/Y coordinates. Several possible influencing factors of L. principis-rupprechtii seedlings’ natural regeneration were also investigated. The results showed that the spatial distribution patterns of Larix principis-rupprechtii seedlings were concentrated 0–5 m around adult trees when considering the main univariate distribution type of regeneration. There was a positive correlation at a scale of 1.5–4 m between seedlings and adult trees according to bivariate analyses. When the scale was increased, these relationships were no longer significant. Generally, adult trees raised regenerated L. principis-rupprechtii seedlings at a scale of 1.5–4 m. Principal component analysis showed that the understory herb diversity and litter layer had a negative correlation with the number of regenerated seedlings. There was also a weak relationship between regenerated numbers and canopy density. This study demonstrated that the main factors promoting natural regeneration were litter thickness, herb diversity, and the distance between adult trees and regenerated seedlings. Additionally, these findings will provide a basis for the late-stage and practical management of natural regeneration in northern China’s mountain ranges.

Plant diversity assessment of selected forest sites of Gaya district of Bihar, India

Regular inventorization and monitoring of biodiversity is paramount for its conservation and sustainable utilization. Gaya district of the Bihar is endowed with rich biodiversity. For proper understanding of plant diversity, quantitative status of the vegetation is essentially required. The aim of the study was to assess different forest sites of the Gaya district of Bihar in India for their plant diversity. Study was carried out in these randomly selected eleven forest sites (Site I to Site XI). A total of 174 species belonging to 150 genera and58 families(48 Dicotyledons, 7 monocotyledons and 3 pteridophytes) were reported from all eleven study sites. Five largest families in the area were Poaceae (22 spp.), Fabaceae (14 spp.), Asteraceae (11 spp.), Rubiaceae (9 spp.) and Acanthaceae (7 spp). Different diversity attributes such as Important Value Index (IVI ), Species richness, Shannon Wiener index, Concentration of dominance and Evenness for tree, shrub and herb layers were estimated. For different sites highest IVI values for tree, shrubby and herbaceous layers were reported.Shannon wiener Index values for tree, shrubby and herbaceous layer of Nagobar site were estimated3.376, 1.986 and 2.350 respectively. Tree diversity was highest at Nagobar site whereas shrub and herb diversity was also reasonably better than most of the sites. Hence, it was revealed from the study that Nagobar site was most diverse site in the Gaya district. Study will be immense use for officials of forest department, researcher, students etc. for carrying out conservation and management work. Similar kind of study should be carried out in different forest sites of the country to get capture the status of the plant diversity for conservation and sustainable utilization.

Vegetation and Soil Characteristics of Plantations in a Part of Western Himalaya

Recognizing the role of plantations in bioresource conservation, four plantations namely Department of Non-renewable Energy Sources (DNES), Eucalyptus, Rose, and Tea were surveyed and sampled in a part of Western Himalaya. Total of 96 plant species belonging to 52 families were recorded from the plantations. Poaceae, Asteraceae and Rosaceae were the dominant families while seven species namely Bidens pilosa, Clinopodium vulgare, Erigeron annuus, Euphorbia heterophylla, Eupatorium adenophorum, Oxalis corniculata, and Pouzolzia zeylanica were common to all the plantations. Maximum tree density was recorded in DNES plantation (36.63±28.10/100m2), while maximum shrub density was in Tea plantation (20.50±2.10/25 m2). Rose plantation, on the other hand, had the highest herb density (210.83±57.30/m2). Tree (2.547) and shrub diversity (2.382) was highest in DNES, while the herb diversity was highest (2.594) in Tea plantation. The pH of the soil from these plantations 4.37 in Tea plantation to 4.77 in Rose plantation. Amongst the four plantations, maximum similarity was between DNES and Eucalyptus plantations (22%) and added together the four plantations account for 3% of the Flora of Himachal Pradesh.