Ideas and Approaches for Studying Treelines in the Himalayas: Expanding the Concept from a Landmark to Community and Ecosystem Levels
Here, we report research design, methodological framework and preliminary findings of a treeline research, based on several sites covering much of the Indian Himalayas. Apart from investigating tree populations, this study expands the treeline concept to community and ecosystem levels. A treeline ecotone consists not only of trees but also several species of herbs and other growth forms. The paper sheds light on methods to delineate treelines and timberlines and to characterize species distribution patterns. Treeline landscapes have complex mosaics of ecosystems, diverse in physiognomy, such as forests, juniper mats and rhododendron krummholz, isolated trees and trees in clusters and rows. Several ecosystem characters change rapidly as forests approach treelines, including a drastic drop in biomass accumulation, which leads to treeline formation. A compilation of treeline elevation studies at the regional level indicates that its elevation can vary widely, by 1800 m across the Himalayan Arc. A similar elevational range is indicated by mapping with the help of remote sensing. The common treeline genera are Betula, Abies, Picea and Juniperus, forming almost all treeline forms described in the literature. We found a relatively lower Temperature Lapse Rate (TLR) value, partly because of elevation-dependent warming (EDW) which needs to be analysed. The upward movement of treelines due to climatic warming could be restricted by pre-monsoon droughts as the studies based on tree ring width chronology suggest. During winters, trees have access to water for only a limited part of the day as the soil remains frozen most of the time. Response to early snowmelt seems to vary from species to species.
KeywordsClimate change Dependent warming Elevation Phenology Pre-monsoon drought Temperature lapse rate Treeline-timberline mapping Tree-water relation
The research was supported by MoEFCC, Government of India, under National Mission on Himalayan Studies (NMHS) contributions of project team members, namely, Subrat Sharma and his associates of GBPNIHESD, Almora (treeline mapping); Rajesh Joshi and his associates of GBPNIHESD, Almora (Temperature Lapse Rate); Hemant Badola and associates of GBPNIHESD Sikkim Unit (vegetation and species diversity: Sikkim study site); RS Rawal and his associates of GBPNIHESD, Almora (vegetation and species diversity: Uttarakhand study site), Zafar Reshi and his associates of Kashmir University (vegetation and species diversity: Kashmir study site); GCS Negi and his associates of GBPNIHESD, Almora (phenology); Ashish Tewari and his associates of Kumaun University, Nainital (tree-water relation); Parminder Ranhotra and his associates of BSIP, Lucknow (tree-ring chronology); BS Adhikari and his associates of WII, Dehradun (snow cover and snow removal experiments); and Pankaj Tewari and his associates of CHEA, Nainital (livelihood interventions) are acknowledged with gratitude. One of us (SP Singh) is thankful to Indian National Science Academy, New Delhi, for their liberal support.
- Adhikari BS, Rawat GS (2012) Structural and functional attributes of forests along an altitudinal gradients in Garhwal Himalaya. Glimpses on Forestry Research in the Indian Himalayan Region, special issue in the International Year of Forests-2011. ENVIS Centre on Himalayan Ecology, Kosi-Katarmal, Almora – 263643, India Chapter 4: 41–53Google Scholar
- Garkoti SC, Singh SP (1992) Biomass productivity and nutrient cycling in alpine Rhododendron community of Central Himalaya. Oecologica Mountana 2:21–32Google Scholar
- Körner C (1999) Alpine plant life. Functional plant ecology of high mountain ecosystems. Springer, Berlin/HeidelbergGoogle Scholar
- Singh SP, Rawal RS (2017) Manuals of field methods. Central Himalayan Environment Association, NainitalGoogle Scholar
- Singh JS, Singh SP (1992) Forests of Himalaya. Gyanodaya Prakashan, NainitalGoogle Scholar
- Singh J, Yadav RR (2000) Tree-ring indications of recent glacier fluctuations in Gangotri, Western Himalaya, India. Curr Sci 79(11):1598–1601Google Scholar
- Singh SP, Tyagi V, Sah P, Jina B (2005) Species diversity contributes to productivity – evidence from natural plant communities. Curr Sci 89:548–552Google Scholar
- Yao T, Thompson L, Yang W, Yu W, Gao Y, Guo X, Yang X, Duan K, Zhao H, Xu B, Pu J, Lu A, Xiang Y, Kattel DB, Joswiak D (2012) Different glacier status with atmospheric circulations in Tibetan Plateau and surroundings. Nat Clim Chang 2:663–667. https://doi.org/10.1038/NCLIMATE1580CrossRefGoogle Scholar