Climate warming stimulates growth and reproduction in cold-adapted plants but also leads to extreme weather events that may hinder their performance. We examined these predictions in the cold-arid Himalayan subnival zone at 5900 m, where unprecedented warming and extreme snowfalls occurred over the past three decades. We collected 205 individuals of Ladakiella klimesii, analyzing climate influences on their growth and recruitment through annual growth rings. Radial growth was highly sensitive to summer temperatures, with warmer conditions significantly enhancing growth. However, increased winter precipitation negatively impacted growth and recruitment by shortening the growing season. Warmer winters and springs, combined with autumn snow cover, favored recruitment, while extreme late winter and summer snowfall disrupted growth and recruitment through intensified soil disturbances. We also found a trade-off between growth rate and longevity: Plants established during warmer periods grow rapidly but have shorter lifespans, whereas those emerging in colder conditions grow more slowly yet persist longer, with implications for long-term population stability. These findings highlight the complex relationship between growth, longevity, and survival in a shifting climate. Although warming promotes growth, it may also decrease longevity and population persistence. The rising frequency of extreme snowfall presents new survival challenges for the world's highest-occurring plants.

• Keywords
• alpine ecosystems, climate warming, frost‐free days, growth ring analyses, growth–longevity trade‐off, herb‐chronology, plant recruitment and growth, subnival plants,
• MeSH
• Global Warming * MeSH
• Climate Change * MeSH
• Altitude * MeSH
• Seasons MeSH
• Snow * MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH

As an evolutionary achievement of almost all terrestrial plants, lignin biosynthesis is essential for various mechanical and physiological processes. Possible effects of plant cell wall lignification on large-scale vegetation distribution are, however, not yet fully understood. Here, we present double-stained, wood anatomical stem measurements of 207 perennial herbs (Potentilla pamirica Wolf), which were collected between 5550 and 5850 m asl on the north-western Tibetan Plateau in Ladakh, India. We also measured changes in situ root zone and surface air temperatures along the sampling gradient and applied piecewise structural equation models to assess direct and indirect relationships between the age and size of plants, the degree of cell wall lignification in their stems, and the elevation at which they were growing. Based on the world's highest-occurring vascular plants, the Pamir Cinquefoils, we demonstrate that the amount of lignin in the secondary cell walls decreases significantly with increasing elevation (r = -0.73; p < 0.01). Since elevation is a proxy for temperature, our findings suggest a thermal constrain on lignin biosynthesis at the cold range limit of woody plant growth.

• Keywords
• Tibetan Plateau, alpine ecology, dendrochronology, plant growth, treeline research, wood anatomy,
• MeSH
• Cell Wall * metabolism   MeSH
• Wood * anatomy & histology   growth & development   MeSH
• Plant Roots metabolism   anatomy & histology   MeSH
• Lignin * metabolism   MeSH
• Altitude MeSH
• Potentilla metabolism   physiology   MeSH
• Plant Stems metabolism   anatomy & histology   growth & development   MeSH
• Temperature * MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• India MeSH
• Names of Substances
• Lignin * MeSH

BACKGROUND AND AIMS: Alpine cushion plants can initially facilitate other species during ecological succession, but later on can be negatively affected by their development, especially when beneficiaries possess traits allowing them to overrun their host. This can be reinforced by accelerated warming favouring competitively strong species over cold-adapted cushion specialists. However, little empirical research has addressed the trait-based mechanisms of these interactions. The ecological strategies of plants colonizing the cushion plant Thylacospermum caespitosum (Caryophyllaceae), a dominant pioneer of subnival zones, were studied in the Western Himalayas. METHODS: To assess whether the cushion colonizers are phylogenetically and functionally distinct, 1668 vegetation samples were collected, both in open ground outside the cushions and inside their live and dead canopies, in two mountain ranges, Karakoram and Little Tibet. More than 50 plant traits related to growth, biomass allocation and resource acquisition were measured for target species, and the phylogenetic relationships of these species were studied [or determined]. KEY RESULTS: Species-based trait-environment analysis with phylogenetic correction showed that in both mountain ranges Thylacospermum colonizers are phylogenetically diverse but functionally similar and are functionally different from species preferring bare soil outside cushions. Successful colonizers are fast-growing, clonal graminoids and forbs, penetrating the cushion by rhizomes and stolons. They have higher root-to-shoot ratios, leaf nitrogen and phosphorus concentrations, and soil moisture and nutrient demands, sharing the syndrome of competitive species with broad elevation ranges typical of the late stages of primary succession. In contrast, the species from open ground have traits typical of stress-tolerant specialists from high and dry environments. CONCLUSION: Species colonizing tight cushions of T. caespitosum are competitively strong graminoids and herbaceous perennials from alpine grasslands. Since climate change in the Himalayas favours these species, highly specialized subnival cushion plants may face intense competition and a greater risk of decline in the future.

• Keywords
• Abiotic stress, Himalaya, Ladakh, alpine, arid, competition, facilitation, global warming, plant–plant interactions, subnival plant communities,
• MeSH
• Biodiversity MeSH
• Biomass MeSH
• Caryophyllaceae growth & development   MeSH
• Species Specificity MeSH
• Climate Change * MeSH
• Magnoliopsida growth & development   MeSH
• Altitude * MeSH
• Life History Traits * MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• India MeSH

Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) form symbiotic relationships with plants influencing their productivity, diversity and ecosystem functions. Only a few studies on these fungi, however, have been conducted in extreme elevations and none over 5500 m a.s.l., although vascular plants occur up to 6150 m a.s.l. in the Himalayas. We quantified AMF and DSE in roots of 62 plant species from contrasting habitats along an elevational gradient (3400-6150 m) in the Himalayas using a combination of optical microscopy and next generation sequencing. We linked AMF and DSE communities with host plant evolutionary history, ecological preferences (elevation and habitat type) and functional traits. We detected AMF in elevations up to 5800 m, indicating it is more constrained by extreme conditions than the host plants, which ascend up to 6150 m. In contrast, DSE were found across the entire gradient up to 6150 m. AMF diversity was unimodally related to elevation and positively related to the intensity of AMF colonization. Mid-elevation steppe and alpine plants hosted more diverse AMF communities than plants from deserts and the subnival zone. Our results bring novel insights to the abiotic and biotic filters structuring AMF and DSE communities in the Himalayas.

• MeSH
• Biodiversity * MeSH
• Endophytes classification   cytology   genetics   physiology   MeSH
• Phylogeny MeSH
• Plant Roots microbiology   MeSH
• Microscopy MeSH
• Mycorrhizae classification   physiology   MeSH
• Altitude MeSH
• Symbiosis * MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• India MeSH