Grass silica short cell phytoliths (GSSCPs), which are profusely produced within the grasses are often subfamily-specific and hence may act as one of the reliable plant proxies in deciphering eco-climatic conditions of an area. To assess how reliably grass phytolith morphs can capture the signal of rainfall variations of an area and to overcome the bias caused due to the redundancy and the multiplicity of GSSCPs, some Chloridoid grasses and soil samples from Maharashtra part of the Western Ghats along the west-east rainfall gradient are studied. The study reveals that Saddle are the dominant morphotype produced by the members of this grass subfamily irrespective of the rainfall variations. Surface soil phytolith assemblage revealed that Saddle morphs are inversely proportional to rainfall i.e., they increase with decrease in rainfall and vice versa. Based on this data, regions with MAP >2000 mm and <2000 mm could be separated in the northern Western Ghats. The results of the CCA and PCA also corroborated these observations.

The Indian Central Himalaya Region (ICHR), the northern topographic front of the Indian summer monsoon (ISM), is an ideal location to study topography-climate interactions because two weather systems-the ISM and mid-latitude westerlies (MLW)-create distinct eco-climatic regimes from tundra (north) to tropical (south). The region's paleoclimatic studies show considerable climatic variations since the late Pleistocene. We evaluated 29 paleoclimatic records from the region and synthesized the results semi-quantitatively using the weighted palaeoclimate index (WApCI) to better understand the important climatic events and their driving mechanisms. According to the WApCI, the region has at least six enhanced monsoonal periods and eight drier spells during the past 34 ka. The cold-dry climatic events, such as the last glacial maxima (LGM), Younger Dryas (YD), 8.2 ka, and 4.2 ka, are associated with northern-hemisphere (NH) climate dynamics and propagated via MLWs. While, the warmer phases are dictated by the insolation-driven ISM dynamics. The WApCI's reconstructed rainfall anomaly aligns with paleoclimatic-model experiments for dynamically generated Paleoclimate Modeling Intercomparison Projects (PMIP3/PMIP4) rainfall for chosen time-slices (last-millenium, historical, mid-Holocene, and LGM). Finally, the Granger causality test determines the temporal relationship between the climatic drivers/forcing indices and primary meteorological parameters. The results showed that summer and post-monsoon precipitation is primarily influenced by total solar irradiation, winter precipitation is driven by a complex mix of variables, and pre-monsoon precipitation is driven by the Arctic oscillation. Based on the facts, we hypothesize that past climate variability demonstrates a complex interplay of local and hemisphere teleconnections in ICHR's climate dynamics.

To develop a phytolith (biogenic silica) reference and to understand the eco-climatic indicative values of some grass silica short cells (GSSCs) occurring in the bamboos (Bambusoideae grasses), one of the chief floral components of eastern and north-eastern parts of India, we studied 44 modern bambusoid grasses and 26 surface soils from different eco-climatic zones covering both the plains and mountainous regions. Of the diverse phytoliths retrieved from the bamboos, Saddle tall and Saddle collapsed were the most abundant types (except in Yushania maling) and these types were also common in surface soil phytolith assemblages of the eastern and north-eastern parts of India. To assess the environmental sensitivity of most consistent morphotypes, we categorized two commonly occurring GSSC morphotypes namely Saddle tall into three groups based on their length and Saddle collapsed into two groups based on their length to width ratio respectively. Pearson's correlation analysis, principal component analysis (PCA), and redundancy analysis (RDA) were used to understand if these morphotypes could distinguish different eco-climatic conditions. Variability of Saddle tall and Saddle collapsed types (both morphometric and abundance) in bamboos growing in these parts of India is a function of mean precipitation of the wettest quarter (MPWeQ) and mean temperature of the driest quarter (MTDQ). The present results served as a baseline for reevaluating the interpretations of a Late-Holocene fossil phytolith record from the eastern Himalaya further validating the potential of Saddle tall and Saddle collapsed types in reconstructing past climate variability in a wide geographical region.

Monsoon precipitation plays a crucial role in shaping the diversity of vegetation in the Himalayas, both in terms of temporal and spatial distribution. While palynology has traditionally been employed to reconstruct the past climate of the Himalaya, there has been limited understanding of how monsoon-related changes affect the structure and distribution of vegetation. To address this, we analysed pollen data from a 3 m deep sedimentary profile in the higher Sikkim Himalaya to reconstruct monsoon driven changes in vegetation diversity. Our results show a highly fluctuating trend of pollen and diversity parameters at late-Pleistocene-Holocene transition for which fluctuating hydroclimatic conditions and differential pollen preservation in coarser sediments is attributed. During the Early Holocene (10,438–7934 cal yrs BP) favourable hydroclimatic conditions led to a rapid expansion of mixed broad-leaved forests, marked by higher values of richness and alpha diversity. Between 7934 and 5481 cal yrs BP, the region experienced moderate hydroclimatic conditions that facilitated expansion and diversification of woody taxa, and correlated with the global Holocene Climate Optimum (HCO). Conversely, from 5481 to3949 cal yrs BP, declining total pollen count (TPC), species richness, and alpha diversity indicates significant shifts in vegetation composition under deteriorating climatic conditions, which corresponds with the 4.2 ka event worldwide. From 3949 to 2049 cal yrs BP, an increasing yet variable trend in TPC and diversity indices, suggests warm-humid conditions prevailed in the region. During the last 1086 cal yrs, an increasing trend is recorded in the palyno assemblage and diversity parameters suggesting ameliorating climate, matches well with the Mediaeval Climate Anomaly (MCA). Our inferences suggest that the palyno assemblage and diversity parameters are quiet sensitive to warm and humid conditions.

Modern surface analogue dataset combining biotic and abiotic proxies (i.e., pollen, phytolith, diatom, stable carbon and nitrogen isotopes of organic matter, soil geochemical and textural parameters together with magnetic susceptibility) were generated from the Ghaghara-Gandak and Ganga-Ghaghara interfluves of the Central Ganga Plain (CGP) to determine the extent to which comprehensive multiproxy data can distinguish different types of depositional sub-environments (lacustrine and fluvial deposits; cropland and forestland). This modern analogue aims to provide basis to reconstruct reliable palaeoecological changes of the CGP, India during the Late Quaternary. The pollen assemblages reflect the mixed deciduous forest under a warm and humid climate in response to rainfall variations in the region. The anthropogenic activities could be well observed in the CGP through marker pollen taxa like cereal, Solanaceae and Brassicaceae. The overall pollen, phytolith, and diatom data indicate a comparatively denser vegetation cover and ecological variability in the Ghaghara-Gandak interfluve than in the Ganga-Ghaghara region. The 813C and TOC/TN values in the sediments indicate a mixed C3-C4 source of vegetation in the lakes and rivers of both the interfluves. However, the sediments from the forest floor indicate relatively lower 813C values (-27.6 to 29.1 parts per thousand), indicating the typical C3 source of vegetation. The low kurtosis values suggest fine-grained sediments combined with low-energy-level reworking in the two interfluves. The Principal Component Analysis (PCA) and Box-plot of the different proxy data was used to test if the soil from different depositional settings can be distinguished or not. Thus, the generated multiproxy data are consistent with the extant ecology and depositional setting, although some site-by-site variations were observed and are indicative of taphonomic bias, climatic alterations, geological, and anthropogenic factors. The present multiproxy analogue should be taken into account while reconstructing the past environment and ecology of the CGP and adjoining region.

We combine phytoliths, non-pollen palynomorphs, stable carbon isotopes of sediment organic matter, environ-mental magnetic parameters and sediment texture data of a lacustrine sedimentary archive from the Bengal region to understand the ecosystem response to past hydroclimatic changes. The region experienced a high In-dian summer monsoon (ISM) rainfall during c.10.2-5.6 ka corresponding to the Holocene Climatic Optimum (HCO) when the lake level was high. Our study reveals that ISM weakened at c.4.3 ka with a decline in lake level, became strong between c.3.7 and 2.1 ka and then shifted towards a drier mode. However, this weakened phase was punctuated by a stable phase between c.1-0.8 ka, and a comparatively stronger phase between c.0.2-0.1 ka corresponding to the Medieval Warm Period (MWP) and Little Ice Age (LIA), respectively. An eutrophication of the lake began at c.3.7 ka which was completely in-filled during c.0.2-0.1 ka. A comparison of the present results with published records suggests millennial-scale coherence in the Holocene ISM variability across the Bay of Bengal (BoB) moisture source regions while, the finer-scale incongruities are attributable to differential proxy response and dating uncertainty. Our proxy-based observations are also compared with a few palaeo-model outputs for selected time-spans [such as, 1550-1850 CE (0.4-0.1 ka), 900-1300 CE (1-0.6 ka), 2100-2000 BCE (4.1 -4 ka), and 4050-3350 BCE (6-5.3 ka)] from the Palaeo Modeling Intercomparison Project Phase 3-4 (PMIP3/PMIP4) experiments which support the assumption that changes in lake ecosystem may be strongly influenced by ISM rainfall, and the region surrounding northern BoB received higher precipitation than the other parts of India since the past 10.2 ka. The millennial-scale variations in the ISM rainfall may largely be attributed to gradual decline in orbital insolation and dynamics of Inter tropical Convergence Zone (ITCZ). However, centennial scale variations may be collectively triggered by forcings like NAO, ENSO and IOD.

Palynology is one of the most reliable tools for the reconstruction of past vegetation and climate and modern pollen analogues are important for the calibration of fossil pollen assemblages. The present study analyses the pollen–vegetation relationships along a steep altitudinal gradient (2700–3680 m), in the western Higher Himalayan region. On the basis of altitude, three vegetation zones were demarcated: Zone I (2700–3100 m) is composed of mixed-temperate forest vegetation, dominated by Quercus semecarpifolia and Rhododendron arboreum; Zone II (3100–3250 m) is marked by sub-alpine forest vegetation, characterised by R. campanulatum and R. barbatum, along with Abies spectabilis and Q. semecarpifolia; Zone III (3250–3680 m) is above the tree-line (3250 m) and represented by alpine-scrub and meadows. Thirty-five surface soil samples (twenty, seven and eight from each zone, respectively) were analysed along the altitudinal transect to decode the representation of the extant vegetation in the pollen-rain. The pollen–vegetation relationship is non-linear due to the over-representation of extra-local Pinus pollen in each zone. Nonetheless, the modern pollen assemblages show a general correlation with the local broad-leaved taxa and the herbaceous elements; with the exception of Rhododendron pollen, which is under-represented. Among the non-pollen palynomorphs (NPPs), the presence of coprophilous fungal spores is compatible with the grazing activities in the area. Multivariate statistical analyses performed on the surface pollen data indicate that the dataset can efficiently distinguish the different vegetation zones across the altitudinal gradient. This work provides the modern analogues for pollen-based palaeoclimatic reconstructions for the Western-Higher Himalayan region, and would also help to decipher the inception and intensification of anthropogenic activities in the region.

Reliability of grass phytoliths for discriminating different deltaic sub-environments has been assessed on the modern surface sediments collected along the salinity gradient of the Sunderbans delta, India. It has been observed that grass phytolith assemblages can successfully distinguish different deltaic sub-environments especially the true mangrove zones from the mangrove associate and non-mangrove zones with minor overlaps, which further corroborated with the results of discriminant analysis (DA). Detrended correspondence analysis (DCA) and redundancy analysis (RDA) performed on the surface grass phytolith data show that salinity is the most crucial environmental parameter influencing grass phytolith distribution in the deltaic sub-environments. The potential of modern grass phytolith data in reconstructing past deltaic environmental changes has been further assessed on a late Quaternary fossil phytolith spectra from the Sunderbans spanning a sedimentary record for the last ~13.6 ka. A true mangrove environment with discernible tidal influence has been revealed between 13.6 and 3.9 ka. Absence of true mangrove–indicator grass phytoliths between ~3.9 and 2.2 ka further suggests disappearance of mangrove vegetation from this part of the Sunderbans which might have recolonized during ~2.2–0.8 ka. A mangrove associated or non-mangrove environment with little or no tidal influence came into existence in the study area since 0.8 ka onwards. A comparison with some earlier records suggests that the present grass phytolith-based palaeoenvironmental data shows conformity with the past dynamics in mangrove ecosystem in the east coast of India in respect to relative sea level changes.

Phytolith assemblages of Shorea robusta Gaertn. (Dipterocarpaceae), an important constituent of tropical deciduous/semi-evergreen forests were studied from six different districts of West Bengal, the western margin of the Bengal Basin. Since S. robusta grows in the tropical mixed dry to wet deciduous and semi-evergreen forests and can tolerate a wide variability in temperature and precipitation regimes, we aim to understand if these climatic parameters drive any changes in phytolith production pattern of the plant. Eleven different phytolith morphotypes retrieved from 13 plant specimens collected along the temperature and precipitation gradients show considerable variations among the specimens. Phytolith assemblages thus retrieved have been subjected to detrended correspondence analysis (DCA), which has helped to understand indirectly the influence of climatic parameter(s) on the phytolith production pattern of S. robusta, if any. Further, canonical correspondence analysis (CCA) performed on the phytolith data reveals how temperature and precipitation influence the variations in phytolith assemblages of the plant. The data provide a basis to understand how phytolith spectra of non-grass plants capture signal of climatic variability of any region and could be used in regional palaeoclimate reconstructions if recovered in fossil sediments.

We synthesise records of stable carbon isotopes (delta C-13 values), TOC/TN, magnetic susceptibility (xlf), palynology, and phytoliths for a late Quaternary lacustrine archive from the northern Gangetic Plain, India to determine the primary driver(s) of past C-3/C-4 plant variability. The study reveals nine climate-driven shifts in vegetation over the last 15.2 ka and provides a comprehensive picture of the evolution of the lake sequence. During 15.2-14.5 ka, lower delta C-13 values, relatively higher TOC/TN ratios and xlf values suggest increasing contribution of C(3 )plant-derived organic matter into the lake and enhanced hydroclimatic conditions in the northern Gangetic Plain. Subsequently, a warm and humid phase corresponding to the B phi lling-Aller phi d interstadial is inferred during 14.5-12.8 ka, followed by evidence of a waning of the Indian Summer Monsoon (ISM) during the Younger Dryas from 12.8-11.7 ka. Despite a strong ISM regime during the early-Greenlandian (11.7-11.0 ka), vegetation shifted from a mixed C-3 -C-4 to a C-4 dominated composition as inferred from higher delta C-13 values, TOC/TN ratios and xlf values. However, a weakened ISM phase is noted between 11.0 and 10.2 ka. On return of warm and humid climatic conditions during 10.2-8.3 ka, tall C-4 Panicoideae grasses flourished around the lake. Two weaker hydroclimatic phases between 8.3 and 6.5 ka and 4.2-2.5 ka favoured C-4-short Chloridoideae grasses over C-4-tall Panicoideae members. Moderate hydroclimatic conditions after 0.6 ka favoured C-4-tall moist-loving grasses. This study shows that before shifting to a C-4-dominated vegetation during the early-Greenlandian to early-Northgrippian, C-3 plants used to dominate the northern Gangetic Plain throughout the late-Pleistocene period. We infer that temperature and rainfall jointly influenced the diversity and distribution of C-4 plants in the northern Gangetic Plain.

Porteresia coarctata (Roxb.) Tateoka is a true halophytic perennial wild grass that grows profusely along newly formed, highly saline landmasses and mudflats in the coastal mangroves of the Indian subcontinent and acts as a pioneer species in mangrove succession. Comprehensive phytolith analyses on sixteen P. coarctata samples collected from different swampy mangrove locations of four mangrove forests (Sundarbans, Bhitarkanika, Godavari and Krishna) along the Indian east coast show the significant and exclusive presence of a new specialized RONDEL having four distinct horns with flat base (named henceforth as RONDEL FOUR HORNED). Significant numbers of this morphotype have also been recorded in the surface sediment samples collected from these swampy mangrove sites. The RONDEL FOUR HORNED is a diagnostic phytolith morphotype of P. coarctata and a useful indicator of coastal swampy or intertidal mangroves of the Indian east coast. This morphotype was then used to identify past coastal intertidal mangrove environments in a late Quaternary sedimentary profile.

Modern feces samples of the endangered red panda ( Ailurus fulgens ) were examined using multiproxy analysis to characterize the dietary patterns in their natural habitat in India. An abundance of Bambusoideae phytoliths and leaves (macrobotanical remains) provide direct evidence of their primary dietary plants. In contrast, Bambusoideae pollen is sporadic or absent in the pollen assemblages. An abundance of Lepisorus spores and its leaves along with broadleaved taxa, Betula , Engelhardtia , and Quercus are indicative of other important food sources. Average δ 13 C values ( − 29.6‰) of the red panda feces indicate typical C 3 type of plants as the primary food source, while the, δ 15 N values vary in narrow range (3.3–5.1‰) but conspicuously reveal a seasonal difference in values most likely due to differing metabolic activities in summer and winter. The multiproxy data can provide a baseline for the reconstruction of the palaeodietary and palaeoecology of extinct herbivores at both regional and global scales.

To assess the pattern of climatic evolution during the late Miocene to early Pleistocene in the largest fluvio-deltaic sedimentary system on the Earth, the Bengal Basin (BB), a quantitative palaeoclimatic reconstruction was made, based on 20 fossil wood floras. Those floras show that moisture-loving taxa have decreased considerably since the Miocene, especially at the western margin of the basin. A quantitative reconstruction of climate parameters reveals that the late Miocene−early Pliocene was warmer and wetter than now, yet with spatial variability. Seasonality of temperature was low in the basin and subsequently increased during the late Pliocene−early Pleistocene. Monsoon intensity was weaker during the interval from the late Miocene to early Pleistocene than the present day. A comparison of the retrieved data with some earlier records from sites either influenced by Indian summer monsoon (ISM) or East Asian summer monsoon (EASM) or both, the two branches of the Asian summer monsoon (AM) provide insights into the temporal and spatial patterns of climate evolution in southern Asia during the late Neogene–Quaternary transition. In general, a drop in temperature and a weakening in ISM strength since the early Pleistocene correlate with the global cooling trend, though with spatial differences.

This study highlights the modern pollen-vegetation relationships along an altitudinal gradient covering the lower temperate (∼2,000 masl) to alpine vegetation zones (∼3,800 masl) in the Bhagirathi valley, western Himalaya. The pollen dispersal dataset compared with the altitudinal vegetation distribution in the valley shows incoherency between the arboreal taxa and their respective pollen proportions. Discriminant analysis (DA) revealed the role of diurnal valley winds in pollen mixing between altitudinal vegetation zones. Pollen of arboreal taxa are transported profusely from the lower temperate vegetation zones to alpine zone. Whereas pollen of non-arboreal taxa, dominantly growing in the sub-alpine and alpine meadows, remain close to their source and represent the prevailing localized environmental conditions in the valley. Study revealed Pinus and Quercus as dominant arboreal pollen taxa throughout the altitudinal transect with a distinct transition in their representation between ∼2,500 and 2,600 masl. High percentage of Pinus (Quercus) pollen below (above) this transition zone nearly corresponds with the present distribution of conifer (pine-oak) and broadleaved (oak-pine) forests in the valley and can be taken as a marker zone to infer palaeoecological changes. The sub-alpine and alpine krummholz, Juniperus and Ericaceae are found autochthonous in their pollen distribution that can serve as good indicators of relative tree-line and glacier dynamics in past. This pollen-vegetation relationship dataset could be an analogue for the interpretation of fossil pollen records in terms of extant vegetation in the mountain regions.

In order to understand the relationship between modern pollen spectra and vegetation, we analysed 20 surface sediment samples collected from the alpine zone of Kalla Bank glacier valley, Dhauliganga Basin, India covering an elevational stretch of c. 3600 to 5000 m asl and vegetation zones like the alpine scrub, alpine meadow and alpine barren. This study also provides insights into the vertical pollen transport along the elevational gradient of the glacier valley. Numerical analyses such as cluster analysis (CA), discriminant analysis (DA) and detrended correspondence analysis (DCA) are used to explore and discuss the modern pollen deposition patterns in the alpine settings. Despite the inconsistencies observed between modern vegetation and surface palynoassemblages, a good agreement is noticed between CA and DA classifications and DCA ordination results which reveal signature of upslope wind transport. High percentages of pine, cedar, alder and birch pollen grains in the above tree-line surface pollen assemblages are indicative of their upslope wind transport from a lower elevation. The inconsistencies may be attributed to the differential pollen representation between species, differential flowering and pollination of herbaceous taxa. The present study suggests altitude and monsoonal winds might be the two most influential factors that attributed changes in the surface palynoassemblages of the alpine vegetation in the Kalla Bank glacier (Kunti-Banar) valley. Therefore, while interpreting the fossil pollen spectra from any high altitude mountainous zone, long-distance pollen transport should always be taken into account, especially for anemophilous plant taxa.

Past climate reconstructions from palaeoecological records require an understanding of relationships between modern vegetation and climate. Phytoliths are being used widely to reconstruct variations in C3/C4 grasses in the past vegetation and corresponding climate. However, little understanding is available on their relationships with the climate driver(s). Even though, the driver(s) regulating C3/C4 grass distributions vary regionally, while reconstructing the past distributions, a grass phytolith-based climatic index (Ic) has often been found to be used globally without assessing its regional consistency. In the Himalaya, the working potential of Ic has proven to be unsatisfactory when compared to other regions of the globe. To improve the efficacy of Ic, we have identified the redundant grass phytolith morphs and revised it by including four exclusive C3-grass indicator morphotypes (bilobate trapezoidal, bilobate scooped, saddle tall and saddle plateaued) to the existing Ic calculation. Thus, a new climatic index, revised Ic (rIc) is proposed in this article. We have compared the rIc with modern climate variables and a relationship with mean annual temperature (MAT) is established with statistical validation. To assess the working potential of the proposed calibration function in the past temperature reconstructions, we have estimated the late Holocene MAT variations in the Himalaya using rIc. We infer that in the mountainous regions like the Himalaya, even with irregular precipitation distribution, variability in C3/C4 grass distributions and their phytolith spectra seem to be a primary function of temperature. Further, we recommend that rIc can be satisfactorily used to reconstruct past temperature variations in the Himalaya and similar mountainous regions where soil water availability is not a limiting factor.

To understand the relationship of phytolith production patterns in regional pteridophytes with elevation dependent climatic variables, and their potential to differentiate vegetation zones of the eastern Himalayan Mountain, we have studied phytolith spectra of 58 pteridophytic species of 22 families from tropical-temperate vegetation belts of Darjeeling, Sikkim and Arunachal Pradesh. Nineteen major phytolith types recovered from foliages and shoots of the pteridophytes are assessed for their potential to distinguish different vegetation zones, if any. Combined data suggest that epidermal polygonal (EP), jig saw plate (JSP), cast of epidermal cells (CEC), globular folded (GF), polyhedral bodies (PB), hair cell base (HCB) and silicified tracheids (FR) are the most significant phytolith morphotypes produced along the tropical-temperate vegetation belts. Of these, CEC and GF could successfully discriminate tropical and sub-tropical from temperate vegetation. PB may be used as indicator of sub-tropical/lower-temperate vegetation and climate, and HCB as indicator of sub-tropical-temperate vegetation and climate. Cluster analysis (CA) applied on the pteridophyte phytolith data shows morphotype signal for different vegetation zones. Discriminant analysis (DA), detrended correspondence analysis (DCA) and redundancy analysis (RDA) have arranged pteridophytic phytolith assemblages along the evapotranspiration and moisture availability gradients, approximating the actual distribution of vegetation along the rising elevation. DA has classified 75% of the taxa into their correct vegetation zones. Misclassification by DA may be attributed to the redundancy of the phytolith morphotypes among the studied taxa and indicating that caution should be taken when applying them in the fossil phytolith assemblages. The study infers a combined influence of climate-energy and moisture availability on the elevational distribution of the pteridophytic phytoliths in the eastern Himalaya. This study indicates that pteridophytic phytoliths have the potential to record regional forest zones despite steep environmental gradients and may be used in interpreting regional fossil pteridophytic phytolith spectra during palaeoclimate reconstructions.

We examined the modern pollen palynomorphs (PP) distribution complemented with non-pollen palynomorphs (NPP) and stable carbon isotopic data of soil organic matter (SOM) to explore relationships of these proxies to vegetation communities in the Chopta valley, a closed valley in alpine zone of the North Sikkim, India, in an attempt to check the efficiency for reconstructing past vegetation and climate. A total of 24 surface soil samples were collected from both the windward and leeward sides of the valley and they did not show any significant difference in the palynoassemblages. The average value of δ13C is −26.6%, which clearly indicates a C3-dominated vegetation in this valley which is also corroborated by the palynological data. However, signature of upthermic wind transport was evident by the significant presence of extra-local and regional forest elements in the palynoassemblages. NPP data indicated grazing activity in the valley and is in conformity with the present-day scenario. Furthermore, cluster analysis (CA) and principal component analysis (PCA) done on the PP and NPP data broadly grouped the samples according to the location of collection to some extent and reflected the relationships among the taxa with the extant vegetation. This study provides a basis for future palaeovegetation and palaeoclimate reconstruction from the region.