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Introduction: The Indian Himalayan forests are remarkable landforms experiencing tremendous climatic variation, constituting complex and diversified ecosystems with prominent vegetation zones. Despite their global significance and substantial research efforts focused on plant diversity in the temperate Himalayan region, only a few studies have explicitly assessed the distribution patterns of understory vegetation in relation to forest compositional types along altitudinal gradients. Methods: To cover a wide range of altitudes and diverse overstory compositions, stands were sampled across four altitudinal ranges from 1500 to 3500 meters above mean sea level with increments of 500 meters in elevation steps. The overstory compositions were classified on the basis of dominant tree species in each stand on the similar sites. Vegetation in the shrub and ground layers was surveyed by visually estimating the percentage coverage within circular plots. Results: A total of 99 understory species including 37 species each in the shrub layer, 62 species in the herb layer vegetation were recorded. The abundance, species diversity and composition of understory vegetation differed significantly along the altitudinal gradient and dominant overstory composition types. Moreover, distinct understory vegetation communities were observed at lower elevations compared to higher elevations, with middle elevations exhibiting intermediate vegetation characteristics. The study also highlighted the importance of dominant overstory composition types in shaping the pattern of understory vegetation abundance, species diversity and composition in the temperate Himalayan region. The higher resource conditions associated with broadleaved stands supported higher understory species abundance at lower elevations, while the heterogeneous conditions induced by the mixedwood stands promoted higher understory species diversity. Conclusion: The hump shaped pattern along the altitudinal gradient appeared to be the most dominant pattern of plant abundance and species diversity and call for more conservation concern towards the middle elevation zones in the temperate Himalayan region. Furthermore, the management interventions should aim at maintaining diverse range of overstory composition types for conserving biodiversity and their ecological functions in the temperate Himalayan region. [ABSTRACT FROM AUTHOR]

The aim of the present investigation was to scrutinize the production of biomass and C storage budgeting that varies in diverse forest types of Himalayan dry-temperate and alpine forest ecosystem, India. Dry-temperate and alpine forest ecosystem is classified into nine forest types viz., 13C1-Dry broadleaved and coniferous forests (DBCF), 13C2a-Neoza pine forest (NPF), 13C2b-Dry deodar forest (DDF), 13C3- West Himalayan high level dry bluepine forest (DBF), 14C1a- West Himalayan sub-alpine birch forest (SBF), 14C1b- West Himalayan sub-alpine fir forest (SFF), 15C1- Birch-rhododendron scrub forest (BSF), 15C3-Alpine pasture (AP) and 16C1-Dry alpine scrub (DAS). Vegetative biomass (trees, shrubs and herbs) was ranged from 0.29 in AP to 252.24 t ha-1 in DDF. Total detritus biomass varied significantly among these forest types with maximum in BSF (5.99 t ha-1) and minimum in DAS (0.11 t ha-1). However, total detritus C density was recorded highest in BSF (3.00 t C ha-1) and lowest in DAS (0.06 t C ha-1). Among forest types total soil C density (humus + soil) varied significantly in 0-40 cm layer. BSF showed maximum C density (130.39 t C ha-1), while minimum was recorded in DAS (37.73 t C ha-1. Total ecosystem C density (vegetation + soil + detritus) among forest types displayed highest value for DDF (212.21 t C ha-1), whereas minimum value (38.43 t C ha-1) for DAS. Hence, this investigation suggests that in dry-temperate and alpine forest ecosystem, DDF should be encouraged for augmentation of biomass and C stock in Indian Himalaya. [ABSTRACT FROM AUTHOR]

Identification of the species for dendrochronological studies is of great relevance to understand various aspects of climate change. However, in the northwestern Himalayan region, dendroclimatological investigations are confined to conifer species, with broadleaved species being disregarded. Thus, the present study was conducted to assess the growth response of seven multipurpose tree species (MPTs), namely Bauhinia variegata, Celtis australis, Grewia optiva, Paulownia fortunei, Toona ciliata, Ulmus villosa and Melia composita to local climate variables, viz. temperature as well as rainfall (seasonal, monthly, average) and CO2 level by evaluating the climatic signal in tree ring chronologies at Solan district, India (altitude 1 250 m) in the mid-hills of the northwestern Himalayas. The results indicated that only the maximum, rainy season temperature and CO2 level varied significantly (P < 0.05) between 1991 and 2017. Only G. optiva exhibited a significant (P < 0.05) tendency toward increased growth. C. australis has a remarkable negative correlation with temperature variables, viz. average, maximum, spring season, March temperature, whereas T. ciliata exhibits a positive correlation with temperature variables, such as rainy season, average and April temperature. Similarly, winter, total and December rainfall have a profound effect on P. fortunei, while March rainfall adversely affected the growth of B. variegata. On the other hand, G. optiva demonstrated sensitivity to both temperature (February and May) and rainfall variables (winter, February and May). U. villosa recorded a positive correlation with rainfall (autumn and October rainfall) but a negative correlation with temperature variables (maximum and April temperature). Elevated CO2 levels affected only two species (G. optiva, M. composita) out of the seven selected species. Our findings will contribute to a better understanding of the climate growth relationships of investigated tree species, as a result, to more accurate projections of the effects of climate change on these MPTs and directing future studies. [ABSTRACT FROM AUTHOR]

Experiment with 45 hybrids (F1s) under 10 x 10 diallel analysis was carried out to estimate the extent of heterosis over mid and better parents for yield and its contributing traits in bitter gourd. The inbreeding depression for various traits was also worked out. Analysis of variance indicated highly significant differences for almost all characters except plant height suggesting presence of wide genetic variability. The heterosis exhibited for fruit characters and fruit yield was mostly positive. Ten cross combinations (DVBTG-1 x VRBT-6, VRBT-94 x VRBT-39, VRBT-94 x VRBT-49, VRBT-94 x VRBT-103, VRBT-94 x VRBT-63, VRBT-94 x VRBT-32, VRBT-94 x VRBT-6, VRBT-41 x VRBT-6, VRBT-103 x VRBT-6 and VRBT-63 x VRBT-32) which recorded high heterosis for yield and also expressed high heterosis for yield components, indicating the additive or synergistic effect on the fruit yield. These cross combinations can be utilized for commercial exploitation and determining the strategies for future in bitter gourd hybrid development. The inbreeding depression results due to fixation of unfavorable recessive genes in F2. In the present results high inbreeding depression indicates the presence of non-additive gene action (dominance and epistasis) for the traits like first male and female flower anthesis, fruit weight, plant height and number of fruits/plant. The minimum inbreeding depression was observed in cross VRBT-32 x VRBT-6 and VRBT-94 x VRBT-49. [ABSTRACT FROM AUTHOR]