Anthropogenic impacts recorded by a 200-year peat profile from the Zoige Peatland, northeastern Qinghai–Tibetan Plateau

Abstract The Tibetan Plateau (TP) is a regional Earth system showing very strong interactions among its lithosphere, hydrosphere, cryosphere, biosphere, atmosphere, and anthrosphere. These interactions manifest TP's impact on surrounding regions and reflect TP's response to the global change. Quantifying the multispherical interactions is critically important to understand the TP environment. Our recent years researches including the ongoing program entitled ‘Tibetan Multi-Spheres Interactions and Their Resource-Environment Significance (TIMI)’, the completed program entitled. ‘Paleo-Altitudes of Tibetan Plateau and Environment (PATE)’, as well as the other relating projects have focused on multidisciplinary research approaches and emphasized on three major pathways: Eurasia-Indian plates collision on deep-Earth dynamics, uplift impact on Earth's mantle–crust dynamics, and contemporary interface on land surface and atmospheric dynamics. Our researches have taken in situ measurement as priority and developed several platforms of data acquisition and analysis, including the platforms of water-phase transformations, and ecosystem observations. Our field investigations have been conducted to obtain data about stratum, paleontology, paleoenvironment, genetic differentiation of animals and plants. We have developed conceptual and mathematical models for crust uplift formation, paleoclimate, glacial melt, water–air interface flux, vegetation climate, and soil erosion. We have also assessed the anthropogenic impacts on environment. Our researches have achieved new and reliable redating of the mantle–crust interaction and initial formation of the TP, found the interaction between tectonics and uplift of the TP and resultant paleoaltitude acting as a spreading source; discovered the interaction between the westerlies and Indian monsoon acting as a control chain that dominates the TP's contemporary environment. The scientific results can play fundamental roles in supporting the TP's resource exploration and societal sustainable development.

Download Full-text

Early human impacts on vegetation on the northeastern Qinghai-Tibetan Plateau during the middle to late Holocene

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133317703035 ◽

2017 ◽

Vol 41 (3) ◽

pp. 286-301 ◽

Cited By ~ 13

Author(s):

Xiao-zhong Huang ◽

Si-si Liu ◽

Guang-hui Dong ◽

Ming-rui Qiang ◽

Zhi-juan Bai ◽

...

Keyword(s):

Tibetan Plateau ◽

Human Activity ◽

Tang Dynasty ◽

Late Holocene ◽

Human Impacts ◽

Anthropogenic Impacts ◽

Lake Basin ◽

Pollen Record ◽

Grassland Degradation ◽

Gonghe Basin

The ecosystems of the Qinghai-Tibetan Plateau are regarded as being primarily regulated by climate because of the harsh environment of the region and the resulting sparse human population. Recent studies have revealed that Neolithic farmers and nomads extensively settled in the northeastern Qinghai-Tibetan Plateau from 5.2 ka (ka = cal ka BP); however, it is unclear how and to what extent human activity has affected its vegetation. Here we combine the results of the pollen analysis of a sediment core from Genggahai Lake, a shallow lake in Gonghe Basin on the northeastern Qinghai-Tibetan Plateau, with archaeological evidence and use them to assess the extent and nature of human impacts on the regional vegetation during the middle and late Holocene. The pollen record indicates that Stellera, an indicator of the extent of grazing-induced grassland degradation, first appeared at 4.7 ka, expanded during 3.6–3.0 ka, and finally increased significantly after 1.6 ka. In support of this finding, archaeological data indicate that the agro-pastoral Majiayao people arrived at ∼5 ka and groups of Kayue people, who practiced pastoralism, intensively colonized the Gonghe Basin and nearby Qinghai Lake basin during 3.6–3.0 ka. After ∼1.6 ka, from the Tang Dynasty onwards, human settlement and grazing activity intensified on the northeastern Qinghai-Tibetan Plateau, and this is in accord with the observed high percentages of Stellera in the pollen record. Based on comparison with other records, we conclude that the sediments of Genggahai Lake provide a record of anthropogenic impacts on vegetation, and that human activity may have contributed to regional forest decline during the middle Holocene, and to grassland degradation in the late Holocene. Grassland degradation caused by human activity may be an indicator of the start of the Anthropocene and potentially may have contributed to global climate change via increased dust emission to the atmosphere.

Download Full-text

Reconstruction of Cultivated Land in the Northeast Margin of Qinghai–Tibetan Plateau and Anthropogenic Impacts on Palaeo-Environment During the Mid-Holocene

Frontiers in Earth Science ◽

10.3389/feart.2021.681995 ◽

2021 ◽

Vol 9 ◽

Author(s):

Zhuoma Wende ◽

Guangliang Hou ◽

Jingyi Gao ◽

Xiaoliang Chen ◽

Sunmei Jin ◽

...

Keyword(s):

Tibetan Plateau ◽

Global Change ◽

Climatic Factors ◽

Anthropogenic Impacts ◽

Rapid Development ◽

Historical Period ◽

Agricultural Activity ◽

Cultivated Land ◽

Land Area ◽

Mountainous Regions

The study of past global change is paramount to comprehending the present and future, as well as to better understand the mechanisms and influences of human–land interactions in a given region. The northeastern margin of the Qinghai–Tibetan Plateau has complex natural environments, sensitive to global change, and renowned for its long history of human occupancy. This makes it an ideal region for the study of anthropogenic impacts on the paleo-natural environment. This paper reconstructed the prehistoric temporal and spatial distribution of cultivated lands on the northeast margin of Qinghai–Tibetan Plateau, and analyzed the Dianziping pollen assemblage to disclose the anthropogenic impacts on the paleo-environment. The results demonstrated that around 4.3–4.0 cal ka BP, the rapid development of the Majiayao culture boosted the population to approximately 39,200 people, over 460 km2 of the land area was converted to cropland, concomitantly, evidence of tree pollen decreased significantly. This marked the earliest identification of anthropogenic impacts on vegetation through agricultural activity in this region. At 4.0–3.6 cal ka BP, the population appeared to have diminished in conjunction with the cultivated land area. Nevertheless, forested areas continued to decrease, primarily due to adverse climatic conditions, but, anthropogenic activities played an undeniable role. Dianziping profile demonstrated the existence of natural forest in the Hehuang Valley during Qijia cultural Period. There was also evidence for the occurrence of regional fire events, suggesting large-scale burning of land cover in the area. This further illustrates anthropogenic impacts. At 3.6–2.6 cal ka BP, populations reached approximately 61,300 people, coinciding with the peak of cropland expansion. Consequently, more of the natural vegetation were converted to crops, and the superimposed influences of farming and grazing aggravated the process of deforestation and vegetation succession. Likewise, deforestation during the historical period can be explained, mostly by human driven causes with limited influence from climatic factors. The extensive exploitation of forest and expansion of cropland consequently resulted in extensive land deterioration, leaving the region with forest islands scattered in less populated, mountainous regions.

Download Full-text