Pramod Kumar Jha

Regeneration of Treeline Birch (Betula utilis D. Don) Forest in a Trans-Himalayan Dry Valley in Central Nepal

Abstract Distribution and community structure of treeline birch (Betula utilis D. Don) forest in a trans-Himalayan dry valley was studied in Manang (central Nepal) with the major focus on regeneration. Along 5 vertical transects, a total of 41 square quadrats (10 m x 10 m) were sampled to determine the importance value index (IVI) of tree species, distribution pattern of seedlings and saplings, and soil attributes. Regeneration was assessed by a density–diameter curve. Moisture plays an important role in spatial (horizontal) distribution of Betula utilis. Pure Betula forest forming the treeline was mature, with high basal area (2.3%), but mixed Betula forest at lower elevations was young. This might have developed after large-scale clear cutting of Abies spectabilis. If not severely disturbed, mixed Betula forest may be replaced by Abies spectabilis. In general, Betula utilis was regenerating, as evident from a reverse J-shaped density–diameter curve for both forests. However, the distribution of seedlings and saplings was spatially heterogeneous and appeared to depend on canopy cover. The stands with highest seedling and sapling densities of Betula utilis had no trees. Betula seedlings were absent where the tree density and basal area (BA) exceeded 20 stems/100 m2 and 1.0% respectively. It was apparent that Betula seedlings could not establish under their own closed canopy even if they produced viable seeds. Partial canopy opening may induce seedling establishment and hence continuous regeneration of Betula utilis at mature stands. The tree-line formed by Betula utilis was abrupt—the anthropo-zoogenic type—without the krummholz zone.

Solid Waste and Water Quality Management Models for Sagarmatha National Park and Buffer Zone, Nepal Implementation of a Participatory Modeling Framework

Abstract The problem of supporting decision- and policy-makers in managing issues related to solid waste and water quality was addressed within the context of a participatory modeling framework in the Sagarmatha National Park and Buffer Zone in Nepal. We present the main findings of management-oriented research projects conducted within this framework, thus providing an overview of the current situation in the park regarding solid waste and water quality issues. We found that most of the solid waste generated in the park is composed of organic matter, paper, and minor reused waste that is mainly reused for cattle feeding and manure, while disposal of other nondegradable categories of collected waste (glass, metal, and plastic) is not properly managed. Particularly, burning or disposal in open dumps poses a great hazard to environmental, human, and animal health, as most dump sites situated close to water courses are prone to regular flooding during the rainy season, thereby directly contaminating river water. Pollutants and microbiological contamination in water bodies were found and anthropogenic activities and hazardous practices such as solid waste dump sites, open defecation, and poor conditions of existing septic tanks are suggested as possibly affecting water quality. Collection of these data on solid waste and water quality and compilation of management information on the targeted social-ecological system allowed us to develop consensus-building models to be used as management supporting tools. By implementing such models, we were able to simulate scenarios identifying and evaluating possible management solutions and interventions in the park. This work reveals insights into general dynamics that can support the quest for solutions to waste and water quality management problems in other protected areas and mountain landscapes where traditional livelihood and land use patterns are changing under the influence of a growing population, changing consumption patterns, and international tourism.

Phenolic-linked biochemical rationale for the anti-diabetic properties of Swertia chirayita (Roxb. ex Flem.) Karst.

The crude extract of Swertia chirayita, an important medicinal plant of Nepal, is locally used for many diseases including type 2 diabetes. In this study, crude aqueous and 12% ethanol solution extracts of S. chirayita collected from nine districts of Nepal were analyzed for anti‐diabetic‐linked anti‐hyperglycemia potential using in vitro biochemical assays. There was moderate‐to‐high positive correlation between antioxidant activity and total phenolic content of both extracts and moderate‐to‐high α‐glucosidase inhibitory activity. Although the anti‐diabetic property of S. chirayita is mainly attributed to the phytochemical swerchirin present in its hexane fraction, we propose that the crude extract of this plant used in local healing also has anti‐hyperglycemia potential. The crude extracts indicated the presence of three main phytochemicals mainly mangiferin, swertiamarin, and amarogentin and their derivatives. Among the standard compounds (mangiferin, swertiamarin, and amarogentin), mangiferin showed α‐glucosidase and 2,2‐diphenyl‐1‐picrylhydrazyl radical inhibitory activity indicating anti‐hyperglycemia potential. Copyright

Responses of Montane Forest to Climate Variability in the Central Himalayas of Nepal

Abstract Climate changes are having dramatic ecological impacts in mid- to high-latitude mountain ranges where growth conditions are limited by climatic variables such as duration of growing season, moisture, and ambient temperature. We document patterns of forest vegetative response for 5 major alpine forest communities to current climate variability in the central Himalayas of Nepal to provide a baseline for assessment of future changes, as well as offer some insight into the trajectory of these changes over time. We used mean monthly surface air temperature and rainfall and the monthly averaged normalized difference vegetation index (NDVI) to compare relative vegetation productivity among forest types and in relation to both climatic variables. Because changes in temperature and precipitation are directly manifested as changes in phenology, we examined current vegetative responses to climate variability in an effort to determine which climate variable is most critical for different alpine forest types. Our results show that correlations differ according to vegetation type and confirm that both precipitation and temperature affect monthly NDVI values, though more significant correlations were found with temperature data. The temperature response was more consistent because at the maximum increased temperatures, there was still an ongoing increase in vegetative vigor. This indicates that temperature is still the major limiting factor for plant growth at higher-elevation sites. This part of the Himalayas has abundant moisture, and some forest types are already saturated in terms of growth in relation to precipitation. Clear increases in productivity are documented on the upper treeline ecotones, and these systems are likely to continue to have increasing growth rates.

Two phenolic glycosides from Curculigo orchioides Gaertn.

One new glycoside derivative from syringic acid and one new phenol glycoside, curculigoside E (1) and orchioside D (2), were isolated and characterized from the rootstock of Curculigo orchioides collected in the Nawalparasi District (Nepal). The structures of the new isolated compounds were elucidated by means of spectroscopic methods such as 1D, 2D NMR and MS.

Plant genetic resources of Nepal : A guide for plant breeders of agricultural, horticultural and forestry crops

SummaryNepal is rich in indigenous wild and landrace plant genetic resources for agronomic, horticultural, forestry, or medicinal uses, but much of this germplasm remains uncollected and awaits economic development. We list 485 entries (species, or genera for ornamental plants) in 14 categories, and compare these to existing germplasm collections in Nepal and the United States to highlight collection and conservation needs. To help plant plant collecting, we outline the key botanical and logistical data and legal framework for planning field work in Nepal.

Seed germination responses of the medicinal herb Centella asiatica

The effect of several environmental factors on germination of medicinal herb Centella asiatica was investigated. Freshly harvested seeds of C. asiatica did not germinate even after gibberellic acid (GA3) treatment and exposure to different treatments with light qualities, while two-three months old seeds exhibited germination (82%) without pre-treatment at warm environment (25 -30oC). GA3 treatment induced germination by two weeks earlier than in control. Germination was significantly (p=0.001) higher in red and white light than in blue and far red light. In addition, germination of C. asiatica was sensitive towards the salt stress and was significantly inhibited at 6500 ppm NaCl. The leaf leachates from invasive weeds Chromolaena odorata, Ageratum conyzoides, Parthenium hysterophorus and Xanthium strumarium showed inhibitory effects on seed germination of C. asiatica. Parthenium hysterophorus had significant effect (p<0.001) on seed germination. These data contribute for the establishing of an efficient protocol for C. asiatica cultivation.

Life history and population status of the endemic Himalayan Aconitum naviculare.

Abstract Sustainable management of rare medicinal plants is becoming a major conservation issue in the Himalaya, and the need to consider population status and life history strategies for sustainable management of these plants has been expressed. We sampled Aconitum naviculare, an endemic Himalayan medicinal plant, to study life history strategies and abundance across 6 sampling sites in Manang Valley, central Nepal. The relationship among environmental variables, life history traits, and abundance was analyzed by using regressions. Seed germination, growth characters, reproductive output, and population density varied significantly across the sites; most of these were lowest at Khangsar, a site located at the highest elevation. Growth characters were largely governed by life forms of associated species. Plant height and petiole length were higher in individuals growing within juniper scrub, whereas tuber mass, flowers/plant, and seed/follicle were higher in open areas. Reproductive outputs were determined by the growth vigor of individual plants and associated species, and not by population size. Stem mass and above-ground biomass declined with elevation, whereas density increased with relative radiation index. Soil attributes could not explain the variation in life history traits and abundance. Associated shrubs reduced the pressure of human collection and destructive effects of animal grazing. In conclusion, a plants life history and responses to different natural environments can explain the variation in abundance of rare species such as A. naviculare.

Improving salinity resilience in Swertia chirayita clonal line with Lactobacillus plantarum

Plants defense responses to abiotic stresses, including salinity stress, involve stimulation of defense related pathways such as biosynthesis of secondary metabolites and induction of endogenous antioxidant enzyme responses. In the present study, a single seed origin clonal line of Swertia chirayita inoculated with Lactobacillus plantarum (LP) was grown under different salinity levels. Control had no LP inoculation. S. chirayita inoculated with LP showed higher accumulation of proline, low proline dehydrogenase activity, up-regulation of pentose phosphate pathway, down-regulation of succinate dehydrogenase activity (Krebs cycle) and low total phenolic content with increased salt concentrations. In comparison, S. chirayita without LP adopted a different biochemical mechanism to counter salt stress (NaCl) by up-regulating both pentose phosphate pathway and Krebs cycle along with stimulation of phenolic biosynthesis. Guaiacol peroxidase (GPX) activity increased with and without LP treatment in response to increasing concentrations of salt. These results indicate that S. chirayita inoculated with LP exhibits a greater salinity stress tolerance than S. chirayita without LP by adopting a more energy efficient defense responses and potentially efficiently partitioning carbon flux between primary and secondary metabolism to counter salt induced oxidative stress.

Phenolic-Linked Antioxidant, anti-Diabetic, and anti-Hypertensive Potential of Wild and Cultivated Swertia chirayita (Roxb. ex Flem.) Karst. Using in vitro Assays

Swertia chirayita, an anti-diabetic medicinal plant needs urgent conservation. Cultivation is an effective conservation approach that can balance market demand and species protection. Aqueous and 12% ethanolic extracts of wild and cultivated S. chirayita were investigated to understand possible variation in potential anti-diabetic-related bioactivity. In general, higher antioxidant activity was found in wild extracts, while higher α-glucosidase inhibitory activity was found in cultivated extracts for all plant parts. This indicates that despite the small differences in their biological functionality, cultivated S. chirayita has the same potential as wild S. chirayita in the management of type 2 diabetes and its related complications.