Indian Himalayan Timberline Ecotone in Response to Climate Change – Initial Findings

Singh, S. P.; Bhattacharyya, A.; Mittal, Amit; Pandey, Aseesh; Tewari, Ashish; Latwal, Avantika; David, Bency; Adhikari, Bhupendra Singh; Kumar, Devendra; Negi, G. C. S.; Mir, Ishfaq Ahmad; Tamta, Krishna Kumar; Sambhav, Kumar; Shekhar, Mayank; Phulara, Mohit; Manzoor, Munisa; Singh, Nandan; Tewari, Pankaj; Ranhotra, Parminder Singh; Singh, Phool; Dhaila, Pratap; Sah, Priyanka; Kumar, R. Suresh; Joshi, Rajesh; Rawal, Ranbeer S.; Rawal, Renu; Singh, Ripu Daman; Shah, Shruti; Sharma, Subrat; Nanda, Subzar Ahmad; Gumber, Surabhi; Singh, Utsa; Reshi, Zafar A.

doi:10.18520/cs/v120/i5/859-871

Cited by 7 publications

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“…Direct measurements of whole-tree transpiration are rare, with Ghimire et al (2014) being the first to compare the variability in transpiration rates between needle-leaved Chir pine ( Pinus roxburghii ) and broadleaved oak forests in Central Himalaya using sap-flow probes. Other studies have also highlighted the crucial role of fluctuations in seasonal soil moisture on phenology and growth cycles in broadleaved trees in the Himalaya ( Singh et al , 2000 ; Tewari et al , 2016 ; Chand et al , 2017 ). The variability in ecophysiological responses of Himalayan trees to seasonal moisture deficit has also been examined across differing elevations, species ranges, and canopy structures ( Zobel et al , 2001 ; Singh et al , 2006 ; Tewari et al , 2018 ).…”

Section: Introductionmentioning

confidence: 99%

Contrasting sap flow characteristics between pioneer and late-successional tree species in secondary tropical montane forests of Eastern Himalaya, India

Kumar

Joseph

Bhutia

et al. 2023

Journal of Experimental Botany

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The interactive role of life-history traits and environmental forcing on plant-water relations is crucial for understanding species response to climate change but remains poorly understood in secondary tropical montane forests (TMFs). Comparing contrasting life-history traits (pioneer vs late-successional species) in a biodiverse Eastern Himalayan secondary TMF, we investigated sap flow responses in co-occurring pioneer species, Symplocos racemosa (n=5) and Eurya acuminata (n=5), and late-successional species, Castanopsis hystrix (n=3), using modified Granier’s Thermal Dissipation probes. The fast-growing pioneers S. racemosa and E. acuminata) had 2.1- and 1.6-times higher sap flux density than the late-successional C. hystrix, respectively, and exhibited characteristics of long-lived pioneer species. Significant radial and azimuthal variability in sap flow (V) between species was observed and attributed to life history traits and the canopy’s access to sunlight. Nocturnal V (1800-0500 hr) was 13.8 % of daily V and is attributed to stem recharge for evening V (1800-2300 hr) and to endogenous stomatal controls for pre-dawn V (0000-0500 hr). Both the shallow-rooted pioneer species exhibited midday depression in V attributed to photosensitivity and diel moisture stress response. In contrast, deep-rooted C. hystrix transpired unaffected across the dry season likely accessing groundwater. Thus, the secondary broadleaved TMFs, with the dominance of shallow-rooted pioneers, are more prone to the negative impacts of drier and warmer winters than primary forests, which are dominated by deep-rooted species. The study provides an empirical understanding of life-history traits and microclimate modulating plant-water use in widely distributed secondary TMFs in Eastern Himalaya and highlights their vulnerability against warmer winters and reduced snowfall due to climate change.

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