Vegetation vis-à-vis Climate and Glacier History during 12,400 to 5,400 yr BP from Dokriani Valley, Garhwal Himalaya, India

Abstract

Palynological analysis from a 10 m deep sediment profile from Dokriani valley, Garhwal Himalaya, provides temporal variation of vegetation vis-à-vis climate and glacier history of the region. This study reveals that between 12,406 and 10,633 cal yr BP vegetation was sparse when the climate was cool-dry and the glacier snout might had been located at lower elevations in comparison to its present position. Subsequently around 10,633 cal yr BP, an increase in the growth of diversified taxa close to the site, indicates the early Holocene climatic amelioration when glacier might have retreated at faster rate. Further, within Holocene some intermittent cool-dry episodes were recorded around 9,670 to 9,000 cal yr BP and 7,100 cal yr BP when glacier might have shown reduction in retreat rate or came to stagnation.originates from the Draupadi ka Danda (5,713 m amsl) and Janoli (6,632 m amsl) peaks. It flows in the direction of NNW to WSW with the length of about 5.5 km and width ranging from 0.08 to 2.5 km. Its present snout position is at an altitude of 3,886 m amsl (Dobhal et al. 2004) and is approachable following the 25 km of mule track from village Bhukki (1,800 m amsl). The melt water of Dokriani glacier forms the Din Gad (stream), which joins the Bhagirathi River near village Bhukki (Fig. 1A). PRESENT DAY VEGETATIONThe valley is characterized by the luxuriant vegetation covering wide range from temperate to alpine type. Its northfacing slopes are densely covered in comparison to the southfacing slopes. The broad leaved-conifer forest is mainly represented by the species of Pinus, Alnus, Corylus, Juglans, Ulmus and that dominates up to the altitude of 2,500 m amsl. Towards higher elevation, it is gradually replaced by species of Pinus, Quercus, Taxus, and Cedrus at 3,000 m amsl and at about 3,500 m amsl this forest is occupied mainly by Abies spectabilis, Quercus semecarpifolia, Betula utilis, and Rhododendron sp. Towards upper limit of this temperate forest, Abies-Betula-Rhododendron form the main constituents growing on the lateral moraines (Fig. 2). These are overtopped by Betula-Rhododendron-Juniperus scurb sub-alpine forest at 3,700 m amsl before merging into alpine

Late Pleistocene–Holocene vegetation and Indian summer monsoon record from the Lahaul, Northwest Himalaya, India

“…The weak summer monsoon during YD cold event is considered as widespread phenomenon as it has been recorded from terrestrial as well as marine records. The sparse vegetation cover and cold-dry climate between~12,720 and 12,136 cal yr BP in Naradu glacier valley, Kinnaur ;from~12,406 to 10,633 cal yr BP in Dokriani valley, Garhwal Himalaya (Bhattacharyya et al, 2011) and in Sumxi Co before 11.6 cal ka BP (Fig. 7H) (Van Campo and Gasse, 1993) are reported as YD cold event.…”

Holocene palaeoenvironmental records from the high-altitude Wular Lake, Western Himalayas

“…Significant summer monsoon moisture is recorded in the Tso Kar Lake (Ladakh, India) around 12,500 yr BP and from 11,500 to 8600 yr BP with low precipitation around 4200 yr BP (Wünnemann et al, 2010). The presence of sparse vegetation confirmed cool and dry conditions in Dokriani Valley in the Garhwal Himalaya from 12,500 to 10,700 yr BP, which was attributed to the cool Younger Dryas (YD) event (Bhattacharyya et al, 2011). The area around the Tso Moriri Lake in Leh experienced an increase in monsoon precipitation from 13,100 to 11,700 yr BP that peaked around 11,200 to 8500 yr BP (Mishra et al, 2015).…”

Record of vegetation, climate change, human impact and retting of hemp in Garhwal Himalaya (India) during the past 4600 years

“…Champion and Seth, 1968; Schweinfurth, 1957; Singh and Singh, 1987). Published pollen records from Garhwal and Kumaun Himalayas indicate regionally variable climatic impacts on vegetation during the Holocene (Bhattacharyya and Chauhan, 1977; Bhattacharyya et al, 2011; Gupta, 1977, 2008; Phadtare, 2000; Phadtare and Pant, 2006; Sharma and Gupta, 1997; Trivedi et al, 2011). Isotopic records from northern Indian speleothems suggest that major climatic inferences linked to the Indian Summer Monsoon (ISM) occurred from 2250 to 1250 BC, and more recently during the ‘Medieval Warm Period (MWP)’ and the ‘Little Ice Age (LIA)’ (Kotlia et al, 2015; Phadtare and Pant, 2006; Sanwal et al, 2013).…”