Paleo-changes in upper range limit of trees provide a valuable analogue for understanding how high-elevational-trees may respond to future climate. Here, we presented a high-resolution (1 km) reconstruction of paleo-changes in the upper range limits of trees across the Tibetan Plateau, at 100-year intervals since the Last Glacial Maximum (~22 kyr BP). This reconstruction was developed by integrating multi-satellite-derived high-resolution map, in situ dendrochronological observation and paleoclimate dataset into a novel climate-driven predictive model.
View Article and Find Full Text PDFThe influence of paleoclimate in shaping current biodiversity pattern is widely acknowledged. However, it remains unclear how the upper paleo-range limit of trees, which dictated the habitat of endemic alpine species, affects the variability in endemic alpine species composition across space over the Tibetan Plateau. We integrated satellite-derived upper range limit of trees, dendrochronological data, and fossil pollen records with a paleoclimate dataset in a climate-driven predictive model to reconstruct the spatio-temporal upper range limit of trees at 100-year intervals since the Last Glacial Maximum.
View Article and Find Full Text PDFMountains with complex terrain and steep environmental gradients are biodiversity hotspots such as the eastern Tibetan Plateau (TP). However, it is generally assumed that mountain terrain plays a secondary role in plant species assembly on a millennial time-scale compared to climate change. Here, we investigate plant richness and community changes during the last 18,000 years at two sites: Lake Naleng and Lake Ximen on the eastern TP with similar elevation and climatic conditions but contrasting terrain.
View Article and Find Full Text PDFSci Total Environ
December 2024
Recently accelerating rate of biodiversity change has triggered exploring the trajectory of plant diversity change from a paleoecological perspective, but the discrepancy and cause of long-term diversity trends from distinct landscapes or ecosystems are largely unknown. Given this, the present study used 41 pollen records from China to investigate the trajectories of plant diversity changes in two distinct land-cover types, i.e.
View Article and Find Full Text PDFSci Bull (Beijing)
August 2024
The term "Holocene temperature conundrum" refers to the inconsistencies between proxy-based reconstructions and transient model simulations, and it challenges our understanding of global temperature evolution during the Holocene. Climate reconstructions indicate a cooling trend following the Holocene Thermal Maximum, while model simulations indicate a consistent warming trend due to ice-sheet retreat and rising greenhouse gas concentrations. Various factors, such as seasonal biases and overlooked feedback processes, have been proposed as potential causes for this discrepancy.
View Article and Find Full Text PDFHow fast the Northern Hemisphere (NH) forest biome tracks strongly warming climates is largely unknown. Regional studies reveal lags between decades and millennia. Here we report a conundrum: Deglacial forest expansion in the NH extra-tropics occurs approximately 4000 years earlier in a transient MPI-ESM1.
View Article and Find Full Text PDFGlob Chang Biol
August 2022
East Asian summer monsoon (EASM)-driven rapid hydroclimatic variation is a crucial factor with major socioeconomic impacts. Nevertheless, decadal- to centennial-scale EASM variability over the last two millennia is still poorly understood. Pollen-based quantitative annual precipitation (PqPann) and annual precipitation reconstructed by artificial neural networks (ANNs) for the period 650-1940 CE were reconstructed from a paleo-reservoir in South Korea.
View Article and Find Full Text PDFProxy-based reconstructions and modeling of Holocene spatiotemporal precipitation patterns for China and Mongolia have hitherto yielded contradictory results indicating that the basic mechanisms behind the East Asian Summer Monsoon and its interaction with the westerly jet stream remain poorly understood. We present quantitative reconstructions of Holocene precipitation derived from 101 fossil pollen records and analyse them with the help of a minimal empirical model. We show that the westerly jet-stream axis shifted gradually southward and became less tilted since the middle Holocene.
View Article and Find Full Text PDFInt J Clin Exp Pathol
October 2016
The aim of the study was to evaluate the antitumor effects of the PPARγ agonist rosiglitazone on the human retinoblastoma. The cell biological behavior was detected, specifically, the effects of rosiglitazone on cell viability and apoptosis of the human retinoblastoma Y79 cells were investigated by MTT assay and Hochest 33258 staining and the migration assay showed that rosiglitazone blocked the invasion and migration of the carcinoma cells through the reconstituted extracellular matrix (Matrigel). The effect of rosiglitazone on NF-κB-dependent reporter gene transcription induced by LPS was analyzed by NF-κB-luciferase assay.
View Article and Find Full Text PDFThe lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation variability is traditionally considered as an East Asian summer monsoon (EASM) indicator, impedes our understanding of the behaviour and dynamics of the EASM. Here we present a well-dated, pollen-based, ~20-yr-resolution quantitative precipitation reconstruction (derived using a transfer function) from an alpine lake in North China, which provides for the first time a direct record of EASM evolution since 14.7 ka (ka = thousands of years before present, where the "present" is defined as the year AD 1950).
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