Search

Reliable tree species diversity and carbon stock data are crucial for establishing a baseline and aiding monitoring and management decision-making to ensure ecosystem functions and services, including carbon management. However, such data are not available for many primary forests, especially in developing countries like Nepal. For this study, we generated primary baseline data on tree species diversity, biomass, and carbon stock for forests under different management regimes in one of the critical landscapes of western Nepal. We sampled 94 clusters of concentric circular sample plots placed systematically at the nodes of 3 km by 3 km square grids in biological corridors (managed by community forest user groups) and a national park's buffer zones (managed by buffer zone user groups) to study the tree species composition and estimate the carbon stock. The number of tree species and botanical families reported in different sites did not differ significantly. The basal area was found to be highest in Brahmadev Corridor where tree density per unit area was also highest. Our study sites showed a basal area ranging from 26.42 to 40.65 m2/ha, which is higher than previously reported from similar forests. The total biomass (302.12 to 496 tons/ha) and carbon stock (142 to 233.12 tons/ha), both being highest in Brahmadev Corridor, were within the range of comparable data and national averages. The number of stems in all sites showed the reverse J-shaped pattern, indicating a stable population and good species recruitment. The buffer zones had a large proportion of forest area with the highest carbon stock classes of 300–400 tons/ha. The basal area and diameter at breast height showed a significant positive correlation with carbon stock, indicating that the basal area is a key determinant of carbon stock. Our study provides disaggregated information on tree species diversity, the quality of forests in terms of stem density and size-class distribution, and carbon stock and its distribution in different carbon stock classes in two forest management regimes. In this sense, our study is the first of its kind in providing important insights into forest and carbon management because areas with different carbon stocks need different management prescriptions.

The gharial (Gavialis gangeticus) is a Critically Endangered species found in Nepal and India. In Nepal, gharials are distributed in Chitwan and Bardia National Parks. Gharials are highly threatened due to various and severe anthropogenic activities. In this study, we assess the attitude, perception and willingness of a range of stakeholders living around Chitwan National Park to participate in gharial conservation. We conducted semi-structured questionnaire surveys with open ended questions. We interviewed national park officials (n = 8), local community group members (n = 54), hoteliers (n = 12), conservation partners (n = 5), local elected representatives (n = 38), fishing community members (n = 14), fishing net sellers (n = 15) and students (n = 9). Our study revealed that respondents are familiar with existing conservation awareness activities and expressed their willingness to participate in gharial conservation activities which can be capitalized on for future conservation initiatives for gharials. Further, we suggest to concentrate efforts particularly on local representatives, fishing net sellers and river dependent communities. These efforts include community level gharial knowledge sharing and interaction program, school teaching program, participating community in gharial conservation and its habitat management intervention and livelihood programs.

Relevance: Sugandhawal (Valeriana jatamansi Jones) is a sub-tropical and temperate traditional medicinal plant, folkloric in Nepal for epilepsy, cholera and neurosis and is used as analgesic, antispasmodic, antiseptic, carminative, diuretic, expectorant and sedative. It serves as a promising source for household economy, primary healthcare and herbal market and remedies, but it is being harvested and traded without considering its sustainability. Thus, the study of its distribution, production, use, trade and conservation is prerequisite to understand its socio-ecological interactions as well as to guide its sustainable production in the future. Methods: We used both primary and secondary data collection methods, and qualitative and quantitative analyses for assessment of production, distribution and use of V. jatamansi. This included laying out 453 quadrats (2 m * 2 m) for inventory plots and 51 group discussions. The occurrence points of V. jatamansi were mapped. We compiled the use records of V. jatamansi at district level by reviewing available ethnobotanical studies carried out so far in Nepal and trade records from Hamro Ban publication (1998–2017). Finally, we modeled the potential distribution of V. jatamansi using a maximum entropy model (MaxEnt) with the help of 201 presence locations collected from the field surveys and secondary references and 20 predictive variables. Results: From the field data, a total of 51 hilly and mountainous districts from east to west were found growing V. jatamansi however, the production and distribution of species were greatly varied and found in 55 districts including those 51. The potential distribution of this species is likely to be expanded northward in mountainous areas with the highest scope in western Nepal. There is a significant convergence between potential distribution and current distribution (production, collection points of species and forest cover) of species. The number of districts with records of production, use and trade of Valeriana were 55, 47 and 39 respectively. A total of 16 use types and 121 use reports were recorded under ethnobotanical uses. The use of V. jatamansi rhizomes in household economy had the highest relative importance value (RIL) (0.18) followed by use for subsistence (0.17), primary health care (0.09), and culture (0.09). Despite the decade-long credentials of growing and traditional uses, V. jatamansi has been traded in markets and exported only after 1995. Now V. jatamansi is found as a major ingredient of local livelihood in remote and rural areas of Nepal. Management of current and potential distribution areas, application of sustainable harvesting practices and promotion of cultivation in off-forest and highlands lead the sustainability of species and local livelihood.

Tree height (H) and diameter at breast height (D) are key variables to calculate tree volume and biomass. We developed a height-diameter (H-D) model for Cinnamomum tamala by evaluating 18 nonlinear models. Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Root Mean Square Error (RMSE), mean bias, Mean Absolute Error (MAE), graphical appearance, and biological logic were the criteria used to evaluate the predictive performance of the models. Gompertz model (M14) performed the best for predicting the total height of C. tamala trees with the least RMSE (1.742 m), mean bias (0.012 m), and MAE (1.342 m) and satisfied model assumptions and biological logic. Validation data ranked the Gompertz model as the best model with RMSE (1.546 m), mean bias (-0.106 m), and MAE (1.149 m). Despite the consistent performance of the Gompertz model, it tended to underestimate the height prediction for taller (dominant crown class) and larger trees. Further work on refitting and validation of the proposed model with data from a larger geographic area, wider-ranging sites, and stand conditions is recommended.