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Linear and non-linear stem volume models have wide-ranging applications in forest resource management owing to their ability to provide reliable estimates of independent variables. In the present study, we have used, diameter at breast height (DBH) and tree height data of Pinusroxburghii and Cedrusdeodara to model stem volume in Pithoragarh district of Uttarakhand. To model tree volume, different stem volume equations were used to develop the relationship. Parameters of volume equations are estimated by regression analysis and the best fit model equation was selected. Validation of modelled equation are performed by using various statistics;coefûcient of determination (R2), root mean square error (RMSE), mean deviation (MD), and mean absolute deviation (MAD) to determine best model fit. The results of the study shows that the models V=a+bD+cD2 for Pinusroxburghiiand V=a+bD2H for Cedrusdeodara performed best in almost all fit statistics in comparison with other model equations. These models would provide better calculation of volume stock and helps in future management of forest. [ABSTRACT FROM AUTHOR]

The impact of climate change on trees is conspicuous in the form of tree line response at the higher mountain region. Based on tree ring data, we investigated the age stand structure and tree line dynamics of the Himalayan fir (Abies spectabilis) at Tungnath, Uttarakhand, western Himalaya. This species forms the upper ecotone limit at ~3335 m asl in association with Rhododendron campanulatum, the latter extending further and forming the krummholz ecotone limit. The stand structure and age distribution of fir reveals the presence of high girth class trees at lower altitudes with the oldest tree of ~379 years age at ~3000 m asl. A good number of trees older in age than the age of uppermost tree (~109 years) at ~3353 m asl show the recruitment of fir at the ecotone limit by the early 20th century AD with the shift rate of ~13 m per decade. The highest advancement rate of ~39 m per decade is found during 18th Century AD. Over 300 years old ring width chronology of silver fir indicates that the temperature of winter months, especially February, have positive influence on the tree growth. The presence of trees younger than 100 years within the forest stand near ecotone limit indicates subsequent infilling of forest and also explains the growth behavior of fir trees in relation to increasing temperature of winter months during the last century. Evidences of no regeneration above the present fir limit and the presence of few seedlings within the upper ecotone limit could be related to mixed response to climate and other local factors at this site. In spite of rapid warming silver fir tree line in Tungnath area has not shown upslope advance. It seems that the positive effect of warming in tree growth is nullified by water stress resulting from increased evapotranspiration. [ABSTRACT FROM AUTHOR]

• Influence of environmental factors on tree species diversity and composition studied. • α-diversity indices showed humped shaped distribution of tree along altitude. • Evenness index showed inverted humped shaped distribution of tree along altitude. • Study revealed strong relationship of tree diversity with environmental and anthropogenic factors. Understanding patterns in forest communities and its driving factors play a critical role in ecological studies. In view of this, present study attempts to understand the role of environmental and anthropogenic factors towards shaping species diversity and composition along the altitudinal gradient (700–3800 m asl) in Indian western Himalaya. A total of 51 tree species (28 families) were recorded; Pinaceae (5) and Fagaceae (5) were the species rich families. α-diversity indices i.e., Margalef's richness index (R), Shannon index (Hʹ) and Simpson index showed a humped shaped distribution, whereas Evenness index (E) showed an inverted humped shaped distribution along the altitude range. Based on non-metric dimensional scaling (NMDS), four different community types were identified. Redundancy analysis (RDA) revealed a strong relationship of tree species composition with environmental (41.73% variation) and anthropogenic factors (17.35% variation). RDA further indicated that the bulk density (BD), disturbance index (DI), mean diurnal temperature range (Bio2) and solar radiation (SR) are significantly associated with sub-tropical (below 1200 m) and lower temperate forest (1200–1700 m) types. Likewise, soil organic carbon (SOC), precipitation of the driest quarter (Bio17) and pH were significantly associated with upper temperate (1700–2900 m), and subalpine forest composition (>2900 m). Both NMDS classification and RDA ordination clearly demonstrate spatial variability in composition of tree community and environmental properties. [ABSTRACT FROM AUTHOR]

• We derived a spatial map of inherent forest vulnerability using ground based observation. • This study was undertaken at 1 km2 resolution using nine forest vulnerability indicators. • Temperate and mixed forests showed higher forest vulnerability compared to subtropical pine & broadleaf and subalpine forests. • Elevation, population density, slope, rainfall, temperature, and aspect are major drivers of forest vulnerability assessment in the Himalaya. Forest vulnerability assessment with ground realities/ data has great implications for adaptation and management planning at local and regional scale. However, such assessments are still limited across globe including the Himalaya. In view of this, present study derived a spatial map of inherent forest vulnerability using ground based observation and information in the western Himalaya. Based on literature and data availability, we selected nine forest vulnerability indicators under four domains i.e., ecological (species richness, and NDVI), climate (temperature, rainfall), topographic (slope, aspect, elevation), disturbances (forest fragmentation) and social (population density). Analytic Hierarchy Process (AHP), which is a multi-criteria decision method, was used for weighting the vulnerability indicators. Based on AHP, forest vulnerability index (FVI) was developed using general linear model approach. The FVI index was further classified into four different categories i.e., low, medium, high and very high. The results revealed maximum (37%) forest grids under medium vulnerable profile followed by 31% (high) and 21% (low) vulnerable grids. In general, temperate and mixed forests show higher forest vulnerability in the region, whereas subtropical pine, broadleaf and subalpine forests falls under lesser vulnerable forest grids. These results exhibited that elevation (15.4%), population density (15.1%), slope (14.5%), rainfall (13.7%), forest fragmentation (12.9%), temperature (12.3), and aspect (11.4%) are the major drivers of forest vulnerability, particularly for the Himalayan region. To validate the results, we compared the developed FVI in present study with ground based FVI already generated in previous studies from the region, and found higher similarity in the assessments. The spatial forest vulnerability maps generated in the present study provides a realistic profile of vulnerable forests in Indian western Himalaya, which can be used for developing adaptation measure and management planning. [ABSTRACT FROM AUTHOR]

• Integrated vulnerability of community forests assessed using index based approach. • FVI was developed by integrating 14 indicators of six different domains. • Results revealed high vulnerability of low and mid zone community forests. • This study conclude local level adaptations cannot be based on global level studies. • This study indicates community forests require urgent attention by concerned government. The Himalaya is often referred to as forested landscape, which provides a range of ecosystem services vital for sustaining life of billions of people. The region is recognized amongst the 35 global biodiversity hotspots for its unique and rich biodiversity. Also, the region is highly vulnerable to perturbations due to anthropogenic disturbances and climate change. Especially the forests in the region are subject to stress from such perturbations. The higher dependency of communities on forests and changing climate has impacts on structure and function of forest ecosystems. This has severe implications for forest dependent communities. Therefore, vulnerability assessment of forests is urgently needed to understand the likely consequences of these changes and responses. Such information would help in developing better management and conservation planning. Earlier studies on vulnerability assessment of forests and forest-dependent people have failed to acknowledge the importance of spatial and temporal aspects of vulnerability investigated through field based observations. Realizing this, present study focuses on forest vulnerability assessment through field based observations along an altitudinal gradient (700–3400 m) in the Indian west Himalaya. This study, for the first time, provides vulnerability assessment of community forests at local scale following integrated approach of multiple indicators across diverse domains. The vulnerability indicators have been identified through a systematic analysis and extensive review of the available literature. A total of 14 indicators in six domains (viz. forest, climate, anthropogenic, topographic, soil and management practices) were identified to assess inherent vulnerability of Community Forests (Van Panchayats) in the target region. Furthermore, Forest Vulnerability Index (FVI) was calculated by integrating the selected indicators across domains. The results revealed high vulnerability at low altitude (<1200 m) forests. Disturbance index, expansion of invasive species and people dependency has emerged as the major factors responsible for forest vulnerability in the region. The value of FVI declined significantly (R2 = 0.51, p < 0.001) with increasing altitude range. The study also analysed perceptions of inhabitant community regarding dependency on forest resources, management practices and status of community forest in the studied area. The outcomes of this study would help in developing management interventions and strategies to ensure sustainable management of forest resources in the targeted landscape in particular and Indian Himalaya in general. [ABSTRACT FROM AUTHOR]