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At a global scale, heat deficits during the growing season result in growth limitations, which determine the elevation of natural alpine treelines. Thus, the expected response to global warming is a treeline advance to higher elevations. However, empirical studies of diverse mountain ranges have yielded evidence of both advancing alpine treelines as well as rather insignificant responses. Based on an extensive collection of field data, we analysed population structures and regeneration patterns, investigated population density-environment relationships and correlated tree growth with climate in order to assess the sensitivity to climate warming of a near-natural treeline ecotone in east-central Nepal. The presence of an elevational zone dominated by a gnarled growth form of Rhododendron campanulatum physiognomically classifies the treeline as a krummholz treeline. The fraction of juvenile tree individuals reflects prolific regeneration and stand densification. The species-specific variation in adult and juvenile stand density along the treeline ecotone depends not only on temperature but also on soil, topographic, and other microclimatic conditions. Rhododendron campanulatum shows highest competitiveness in the krummholz belt under a constellation of site conditions influenced by this species itself. By contrast, Abies spectabilis (Himalayan Silver Fir) and Betula utilis (Himalayan Birch) have gained predominance under warmer and more nutrient-rich habitat conditions in the closed forest below. The dense krummholz belt effectively controls the potential upslope migration of subalpine forest tree species. Abies spectabilis growth-climate correlations show changing growth limitations in the course of the 20th century, most likely due to intensified climate warming in recent decades, when decreasing moisture availability during the pre-monsoon season has affected Abies spectabilis' radial growth. It is evident from our results that to date the treeline has responded to climate warming in terms of stand densities, seed-based regeneration and growth patterns of trees, the treeline position, however, is rather stable. A treeline shift is to be expected in the mid- to long-term only. [ABSTRACT FROM AUTHOR]

[Display omitted] • The evolutionary history of Pleione was investigated using single-copy gene single nucleotide polymorphisms and chloroplast genome datasets. The data revealed that Pleione can be divided into five clades. • Ancestral area reconstruction suggested that Pleione likely originated from the HDM. The uplifting of the HDM drove rapid diversification by creating conditions favoring rapid speciation. This coincided with two periods of strengthening of the Asian monsoon climate, which caused the first rapid diversification of Pleione from 8.87 to 7.83 Mya, and a second rapid diversification started at around 4.05 Mya to Pleistocene. • In addition to revealing the evolutionary relationship of Pleione with orogeny and climate changes, the findings provide insights into the speciation and diversification mechanisms of plants in the East Asian flora. Pleione is an orchid endemically distributed in high mountain areas across the Hengduan Mountains (HDM), Himalayas, Southeast Asia and South of China. The unique flower shapes, rich colors and immense medicinal importance of Pleione are valuable ornamental and economic resources. However, the phylogenetic relationships and evolutionary history of the genus have not yet been comprehensively resolved. Here, the evolutionary history of Pleione was investigated using single-copy gene single nucleotide polymorphisms and chloroplast genome datasets. The data revealed that Pleione could be divided into five clades. Discordance in topology between the two phylogenetic trees and network and D -statistic analyses indicated the occurrence of reticulate evolution in the genus. The evolution could be attributed to introgression and incomplete lineage sorting. Ancestral area reconstruction suggested that Pleione was originated from the HDM. Uplifting of the HDM drove rapid diversification by creating conditions favoring rapid speciation. This coincided with two periods of consolidation of the Asian monsoon climate, which caused the first rapid diversification of Pleione from 8.87 to 7.83 Mya, and a second rapid diversification started at around 4.05 Mya to Pleistocene. The interaction between Pleione and climate changes, especially the monsoons, led to the current distribution pattern and shaped the dormancy characteristic of the different clades. In addition to revealing the evolutionary relationship of Pleione with orogeny and climate changes, the findings of this study provide insights into the speciation and diversification mechanisms of plants in the East Asian flora. [ABSTRACT FROM AUTHOR]

• Agroforestry forms an explicit part of the hill farming systems. • Mostly all the dominant agroforestry systems were prevalent in the study area. • Silvopastoral and agrohortosilviculture have the highest CO 2 mitigation potential. • Along elevation, the highest total carbon stock was recorded in Zone III. The estimation of carbon stock in agroforestry is crucial for curbing the global climate crisis. In this study, biomass production and carbon storage potential of the prevalent agroforestry systems along an altitudinal gradient in the Chamba district of Himachal Pradesh was carried out during 2019–2021. Agroforestry practices were categorized into eight land use systems viz., agrisilviculture, agrihorticulture, agrosilvohorticulture, agrohortisilviculture, hortiagriculture, silvopastoral, pastoralsilviculture and hortipastoral systems and were divided into four altitudinal ranges viz., <1000 m above sea level (m asl; Z-I), 1000–1500 m asl (Z-II), 1500–2500 m asl (Z-III) and > 2500 m asl (Z-IV). Results revealed that biomass production and total carbon storage (vegetation + soil) were significantly affected by the land use type along the altitudinal gradient. Among the different agroforestry systems, maximum aboveground biomass (47.48 Mg ha−1) and belowground biomass (12.20 Mg ha−1) were recorded for agrohortisilviculture. Biomass production was positively correlated with altitudes and increased with an increase in altitudes. Soil carbon density was the maximum (35.77 Mg ha−1) under silvopastoral showing a decreasing trend along the altitudinal gradient. The total carbon storage potential was observed the maximum (59.76 Mg ha−1) under silvopastoral system followed by agrohortisilvicuture > agrosilvohorticulture > agrisilviculture > pastoralsilviculture > hortiagriculture > hortipastoral > agrihorticulture. Along the elevation gradient, total carbon stock ranged from 43.99 to 51.13 Mg ha−1 with the maximum carbon stock corresponding to Z-III and the minimum for Z-IV. This study offers a useful approach for selecting different land use systems and vegetation patterns to maximize thecarbon stocks in a cost-effective manner, which will further help to mitigate global warming issues in other fragile Himalayan catchments. [ABSTRACT FROM AUTHOR]