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[Display omitted] • High resolution proxy data traced late Holocene climate events for western Himalaya. • Sites have traced dry (4.2 ka; Little Ice Age) phases and moist Medieval warm period. • Dry (weak summer monsoon) phases correspond well with decreased solar irradiance. • Traced dry events are more prominent in drier alpine site than moist temperate site. • LIA phase recorded asynchronous response time in Alpine and Temperate pollen data. This study presents a centennial to decadal scale late Holocene climate scenario from the Indian summer monsoon (ISM) dominated region of western Himalaya. The subsurface sediments analyzed for palynology, carbon isotope (δ13C org) and magnetic susceptibility (χlf) were collected from the temperate and alpine meadows, respectively receiving high (low) and relatively low (high) amount of ISM (winter) precipitation. We could identify the dry and moist phases linked to respective weakening and strengthening of ISM. High frequency of steppe pollen (Ephedra , Amaranthaceae, Asteraceae, Brassicaceae) between 4.4 and 3.8 ka represented a dry phase, coeval to 4.2 ka global dry event. Subsequent low δ13C values and high pollen frequency of moist vegetation (Geraniaceae, Cyperaceae, Apiaceae, Ranunculaceae and pteridophytes) till ca. 0.9 ka suggested moist phase but with an intermittent dry episode ca. 2.9–2.5 ka, allowing rise of steppe taxa. Climate ameliorated ca. 1.8 ka and moist conditions further enhanced between 1.5 and 0.9 ka, corresponding to Medieval Warm Period. Sharp increase in δ13C org values and steppe vegetation ca. 0.8 ka attributed to dryness that intensified between 0.6 and 0.2 ka and coincide with Little Ice Age (LIA) anomaly. The recorded dry (weak ISM) phases showed correspondence with the low solar irradiance and supported the teleconnection with north Atlantic circulations. Palynological data from both the valleys complement each other throughout late Holocene time. However, the valleys showed temporal inconsistency in their aridity peaks during LIA phase. This indicates response variability of the two physiographically different sites to summer and winter monsoon systems. [ABSTRACT FROM AUTHOR]

Pollen keys are essential for accurate and consistent identification of Quaternary pollen, as well as pre-Quaternary fossil pollen, which in turn enables a better understanding of past biodiversity and vegetation changes. Here, we present a pollen key to 52 species of arboreal and liana plants from 26 families on tropical Hainan Island, covering representative pollen types identified in tropical Chinese Quaternary deposits. Such a pollen key along with detailed descriptions and illustrations should enable fossil pollen to be accurately identified. Nevertheless, the key is open for future improvement, so that pollen of other plants from the same study area can be accommodated when specimens become available. In their present state they should, however, aid palynological analyses of Quaternary deposits, particularly in tropical south China. Pollen identification as well as the palaeoecological and palaeobiogeographical significance of the key representative communities along the altitudinal gradient in our study area (i.e., coastal mangroves, tropical rainforest and montane rainforest) are also discussed in this paper. [ABSTRACT FROM AUTHOR]