The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences.

Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change and suggest that, without major reductions in greenhouse gas emissions to the atmosphere, terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity.Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Global vegetation over the past 18,000 years has been transformed first by the climate changes that accompanied the last deglaciation and again by increasing human pressures; however, the magnitude and patterns of rates of vegetation change are poorly understood globally. Using a compilation of 1181 fossil pollen sequences and newly developed statistical methods, we detect a worldwide acceleration in the rates of vegetation compositional change beginning between 4.6 and 2.9 thousand years ago that is globally unprecedented over the past 18,000 years in both magnitude and extent. Late Holocene rates of change equal or exceed the deglacial rates for all continents, which suggests that the scale of human effects on terrestrial ecosystems exceeds even the climate-driven transformations of the last deglaciation. The acceleration of biodiversity change demonstrated in ecological datasets from the past century began millennia ago.Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Rice agriculture is the foundation of Asian civilizations south of the Yangtze River. Although rice history is well documented for its lower Yangtze homeland area, the early southward expansion of paddy rice farming is poorly known. Our study investigates this process using a compilation of paleoenvironmental proxies from coastal sediment cores from southeast China to Thailand and Island Southeast Asia. We propose that a shortage of land suitable for paddy fields, caused by marine transgression, constrained rice agriculture during the mid-Holocene. Rapid expansion of coastal plains, particularly in deltaic basins, over the past three millennia has coincided with increases in land suitable for rice cultivation. Our study also helps explain the past population movements of rice farmers.Copyright © 2020 the Author(s). Published by PNAS.

Floods and megadroughts affected the Neolithic cultures in the Yangtze River Delta between 4300 and 4000 years ago.

This paper conducts comparative studies on the distribution of prehistoric cultural sites of Zhejiang Province. The results show that Zhejiang prehistoric culture expanded gradually in this region before 4000 cal. a BP. The notable expansions occurred twice and at the same time the prehistoric culture was disseminated from west to east coast along the river valleys. After 4000 cal. a BP, prehistoric cultural sites-distributed region contracted obviously due to the termination of spreading trend to east coast, which was accompanied by two kinds of economic transitions of Zhejiang. The distribution of prehistoric cultural sites was closely related with sea level fluctuation in Holocene, especially on the banks of the Hangzhou Bay. The changes of prehistoric culture and the climatic environment are identical to each other. It is evidenced that the development, expansion and contraction of prehistoric culture are positively correlated to the climatic environmental change. The change of climatic environment is just the root cause for this change and transition of the economic formation. So the climatic environment is the dominant factor of the Zhejiang prehistoric culture vicissitudes, which has exerted great influence on distribution, dissemination, expansion and transmutation of the culture.

孢粉是重建古植被、古气候的重要基础数据。孢粉数据库对研究样点至区域和全球尺度上的古环境演变规律、古气候变化特征反演和古生物地球化学循环模拟等具有重要意义。该文收集整理了中国1960-2020年间发表和部分未发表的现代花粉数据记录, 包括样品编号、采样位置、采样地经纬度和海拔高度、样品类型、数据来源、数据类型、周边植被信息、参考文献、花粉类群及其含量等信息; 并对数据进行筛选和标准化等处理, 由此整合为中国现代花粉数据集。该数据集由4 497个现代花粉采样点的数据信息组成, 包括660个来自中国第四纪孢粉数据库数据, 1 763个前期整理发表的数据和2 074个近期收集的数据, 涵盖772个花粉类群。样品类型以土壤表层样品(3 332个)为主, 苔藓样品以及湖泊、海洋表层样品等为辅, 广泛分布于全国不同地理区域和植被类型中, 其中以温带荒漠区域(24.91%)和亚热带常绿阔叶林区域(24.02%)最丰富, 其次为温带草原区域(16.14%)和青藏高原高寒植被区域(15.83%)。数据按照来源可分为原始数据(58%)和数值化数据(42%); 按照数据类型可分为原始统计粒数的样点(59%)和以花粉百分比表达的样点(41%)。半个多世纪以来, 科研人员开展了大量的表层现代花粉取样和研究。本数据集虽然仅获取部分记录, 但样点覆盖了我国绝大多数地区, 可有效地用于古植被与古气候重建的现代孢粉与现代植被校验, 并将为中国孢粉数据库的建立与更深入的孢粉研究提供数据支撑。

Human activity has transformed the Earth’s landscapes pervasively for thousands of years, and the most important anthropogenic alteration was the clearing of forests and the establishment of agriculture. As a center of rice domestication and early population growth, the lower Yangtze River has been extensively transformed in the Holocene. However, the timing, extent, and process of deforestation and its relationship with the intensification of rice cultivation remain controversial. Here, four representative archaeological sites ranging from 8,100 to 4,300 cal a BP, that is, Jingtoushan, Hemudu, Yushan, and Xiawangdu sites, were selected for detailed palynological analysis, and evidence of anthropogenic deforestation and subsistence strategy were also synthesized to investigate dynamic human–forest interaction. Although natural vegetation had already been altered at the Jingtoushan site around 8,000 cal a BP, it was more likely to be the management of acorns by limiting burning to open habitats and increasing yield. As the subsistence shifted from acorn exploitation toward rice cultivation after 6,000 cal a BP, real deforestation for agriculture may occur at the Yushan and Xiawangdu sites due to conflict on labor input and land use. However, these deforestations were just confined to the archaeological sites at local scale, and no consistent vegetation change occurred at regional scales induced by human activities until the last 3,000 years.

Pollen and charcoal records derived from the sediment core of Lantianyan (LTY) peat bog, Northern Wuyi Mountain chains, eastern subtropical China, provide valuable information of landscape evolution caused by both climatic variation and anthropogenic activities over the past 8200 years. Our results reveal fluvial and lacustrine deposition between c. 8200 and 5600 cal. yr BP. The high proportion of pollen from evergreen broadleaved forests (e.g. Quercus and Castanopsis) and Alnus trees, a taxon frequently occurring in mountain wetlands, implies a humid interval, which is consistent with the Holocene moisture maximum in eastern China. After 5600 cal. yr BP, the spread of the wooded swamp taxon, Glyptostrobus, suggests shallow water conditions and peat formation caused by gradual drying. The drying trend generally corresponds with the speleothem isotope record from this region, revealing a weakening East Asian summer monsoon (EASM) due to a decrease in Northern Hemisphere summer insolation (and in air temperature). Peaks in the abundance and concentration of Glyptostrobus pollen at c. 4600–4400 cal. yr BP and c. 3300–3000 cal. yr BP suggest two periods of swamp expansions, which coincide with the drought intervals revealed by the speleothem records. The LTY pollen and charcoal record demonstrates that human-induced land cover change was negligible before 3600 cal. yr BP. We consider the first signal of intensive human activity and landscape clearing to be the noticeable increase in charcoal particles at around 3600 cal. yr BP. This anthropogenic impact is followed by a dramatic decrease in arboreal pollen and increase in Poaceae pollen percentages, likely reflecting a transition to rice-paddy agriculture in the study area.

Rice is among the world’s most important and ancient domesticated crops. However, the spatial and temporal pattern of the early rice domestication process remains unclear due to the lack of systematic study of wild/domesticated rice remains and corresponding dates during the early Holocene. Here, we collected 248 samples from five typical Shangshan cultural sites in the lower Yangtze region where is the most likely origin place of rice for phytolith analysis. The results showed the following. (1) Rice bulliform phytoliths from the five sites all present domestication traits, suggesting that the rice domestication process had begun across the region by the early stage of the Holocene. (2) The relative domestication rates reflected by the rice bulliform phytoliths were different between sites, the sites with higher domestication rates were distributed closer to the mainstream river. (3) The rice domestication process revealed by bulliform phytoliths can be divided into three periods during the early Holocene: from 10 to 9 ka, rice domestication began and stayed at a low level under 35%; from 9 to 8.5 ka, rice domestication level increased to 50%; and from 8.5 to 8 ka, rice domestication level was in a fluctuating state. (4) By 9 ka BP, rice double-peaked phytoliths from glume cells are present in most of the studied sites, which imply the presence of crop dehusking processing. This study reconstructed the spatial and temporal patterns of rice domestication during the early Holocene, which will improve our knowledge of early crop domestication and enhance our understanding of changes in rice status.

Wetlands were important resources for the hunting–gathering and early farming communities in coastal areas in the Neolithic. However, the relationship between the development of the wetland environment and the human population remains unclear due to the lack of successive wetland environmental changes throughout the Holocene in coastal areas. Here, the summed probability distributions (SPD) of radiocarbon dates of peat were used as an indicator and combined with archaeological radiocarbon dates to reconstruct the wetland environmental and demographic changes during the Neolithic in the lower Yangtze region. The results showed that the shifts in demographic centers and population development were related to wetland environment with peat formation. The first shift of the demographic center was from the hilly regions to the coastal plain and occurred during ca. 8,300–8,000 cal yr BP, which might be caused by the attractiveness of survival resources offered by the coastal wetland environment and the 8.2 ka event. The second shift occurred from the Ningshao Plain to the Taihu region and might be attributed to the widespread waterlogged environment in the Ningshao Plain. The peak of demographic development coincided with the peak of peat formation during the middle Holocene in the lower Yangtze region, indicating that the wetland environment facilitated changes in human societies. The formation of peat might be related to the sea-level and El Niño-Southern Oscillation events; however, further studies are required for deep comprehension. The present study is an attempt at identifying the past impacts of the wetland environment on demographic development and can form the basis for a more comprehensive understanding of the interactions between the humans and their living environment.

The Artemisia/Chenopodiaceae (A/C) ratio is assumed to be a useful index for reconstructing moisture changes in arid and semi-arid regions. Thorough modern pollen studies are still lacking to understand the reliability and limitation of A/C ratio as a moisture indicator, however. Here we review how well this ratio can be applied in arid and semi-arid China on the basis of new surface pollen data, previous data synthesis and other publications. Results indicate that variance in the A/C ratio can permit identification of modern vegetation types and that the A/C ratio generally has a positive relationship with annual precipitation. However, soil salinity, vegetation community composition, human activity and sample provenance (e.g. soil and lake sediments) will affect the values of the A/C ratio in different vegetation zones and therefore the A/C ratio is not comparable in different regions. We argue that the A/C ratio can only be used to reconstruct vegetation types and climate change in regions with precipitation <450–500 mm, and in steppe, steppe desert and desert areas. Careful studies should be undertaken to understand the modern pollen–vegetation–climate relationships in various regions before using the A/C ratio to interpret vegetation and climate.

Exploring prehistoric variation in human–environmental interaction is critical for understanding the historical patterns and mechanisms of long-term human–land evolution. In this paper we review the published radiocarbon and optically stimulated luminescence (OSL) data from Late Paleolithic, Neolithic and Bronze Age sites in China, analyze the spatial–temporal distribution of these sites, and compare it with the results of recent paleoclimatic and archaeological studies. We seek to study the trajectory and influencing factors of human–environmental interactions in late prehistoric China. We detect changing patterns in the relationship between humans and the environment during different phases of the prehistoric era in China. Climate change clearly affected the environment of hunter-gatherer groups between 50,000–10,000 BP (before present, defined as 1950AD), and variation in human population in Neolithic China (∼10,000–4000 BP) was likely influenced primarily by the development of agriculture, in addition to substantial climate events. The spatial scale of human settlements expanded in the Bronze Age (∼4000–2200 BP) in a period of cooling climate. During this time the impact of human activities on the environment increased significantly, primarily caused by technological innovations related to the onset of prehistoric transcontinental cultural exchange in Eurasia.

Based on the observed daily temperature and precipitation of the land surface of 603 meteorological stations in China, the Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) 3rd generation dataset, the changing patterns of NDVI in China during 1982-2015 were investigated and the corresponding contributions of the main driving forces, climatic change and human activities, to these changes were distinguished using the methods of trend analysis and multiple regression residuals analysis. The results showed that vegetation recovered in whole China in research period significantly. Shanghai was the single case with a decrease in growing season NDVI in the selected 32 provincial-level administrative regions, while the growing season NDVI in Shanxi, Shaanxi, and Chongqing increased much faster compared with other regions. The climatic change and human activities drove the NDVI change jointly as main forces in China and induced both a rapid increasing trend on the whole and a huge spatial difference. The impacts of climatic change on NDVI change in the growing-season ranged from -0.01×10 -3 a -1 to 1.05×10 -3 a -1, while the impacts of human activities changed from -0.32×10 -3 a -1 to 1.77×10 -3 a -1. The contributions of climatic change and human activities accounted for 40% and 60%, respectively, to the increase of NDVI in China in the past 34 years. The regions where the contribution rates of human activities were more than 80% were mainly distributed in the central part of the Loess Plateau, the North China Plain, and the northeast and the southwest of China. There were 22 provincial-level regions where the contributions of human activities were more than 50%, and the shares of contribution induced by human activities in Shanghai, Heilongjiang, and Yunnan were much greater than those of any other regions. The results suggest that we should focus more on the role of human activities in vegetation restoration in the whole country.

基于中国603个气象站的地表气温和降水观测资料以及GIMMS NDVI3g数据,采用变化趋势分析和多元回归残差分析等方法研究了1982—2015年中国植被NDVI变化特征及其主要驱动因素（即气候变化和人类活动）的相应贡献。结果表明：① 1982—2015年中国植被恢复明显,在选择的32个省级行政区中,山西、陕西和重庆的生长季NDVI增加最快,仅上海生长季NDVI呈减小趋势。② 气候变化和人类活动的共同作用是中国植被NDVI呈现整体快速增加和巨大空间差异的主要原因,其中气候变化对各省生长季NDVI变化的影响在-0.01×10 ^-3~1.05×10 ^-3 a ^-1之间,而人类活动的影响在-0.32×10 ^-3~1.77×10 ^-3 a ^-1之间。③ 气候变化和人类活动分别对中国近34年来植被NDVI的增加贡献了40%和60%;人类活动贡献率超过80%的区域主要集中在黄土高原中部、华北平原以及中国东北和西南等地;人类活动贡献率大于50%的省份有22个,其中贡献率最大的3个地区为上海、黑龙江和云南。研究结果建议应更加重视人类活动在植被恢复中的作用。

The North China Plain is a typical diluvial-alluvial plain with an unstable depositional environment and poor sedimentary continuity. However, the effects of changes in sedimentary phases or hiatuses were not considered in previous studies of the sedimentary record of the North China Plain, which limits our understanding of the environmental and climatic evolution of the region during the historical period. Baiyangdian, the largest freshwater lake in the plain, is a potentially valuable archive of regional paleoenvironmental information since the late Pleistocene. We investigated a sedimentary profile (BG-2019; 38°46'2.55"N, 115°49'0.41"E; 7 m a.s.l) in Gaoyang County, in the southwestern part of Baiyangdian Lake region; the profile is ~6 m long. The results of AMS 14C and OSL dating indicate that profile BG-2019 has two intervals of lacustrine facies, two intervals of fluvial facies, one interval of swamp facies, one interval of fluvial-lacustrine delta facies, and two intervals of non-deposition or stratigraphic lacunae. The ages of the various facies are as follows. Lacustrine facies: 10270-13710 cal a BP and 4630-5400 cal a BP; swamp facies: 3470-3700 cal a BP; fluvial-lacustrine delta facies: 7130-8000 cal a BP; fluvial facies: 3700-4630 cal a BP and 3230-3470 cal a BP;; intervals of interrupted deposition: 8000-10270 cal a BP and 5400-7130 cal a BP. Therefore, no continuous lacustrine facies exists in the Baiyangdian region since the Lateglacial. Baiyangdian was a small lake during the Lateglacial, but was more extensive during the middle Holocene, although with discontinuous lacustrine facies. During the late Holocene the lake began to shrink under the influence of climate change and human activity. No other than human activity around the modern Baiyangdian Lake was reserved. Pollen analysis shows that the vegetation landscape of the Baiyangdian Basin differed substantially between the Lateglacial and the middle Holocene. During the Lateglacial, the climate was cold and dry, and vegetation dominated by Artemisia, Chenopodioideae, Poaceae and Asteraceae developed in the plain, while the western mountains had a limited forest cover. During the middle Holocene, when the climate was warm and humid, grassland vegetation dominated by Artemisia, Chenopodioideae and Poaceae developed in the plain; Ceratopteris and aquatic plants flourished in and around the lake; and coniferous-broadleaved mixed forest dominated by Pinus and Quercus developed in the western mountains, with an increased forest cover. During the middle-late Holocene, when the climate was relatively mild and dry, grassland vegetation dominated by Artemisia, Chenopodioideae and Poaceae persisted in the plain; and coniferous-broadleaved mixed forest dominated by Pinus developed in the western mountains, with a high forest cover age.

华北平原晚冰期以来气候环境演变研究对该地区社会发展、灾害风险评估和科学应对未来全球增温背景下极端降水和洪涝事件具有重要意义。本文以华北平原中部白洋淀地区高阳剖面（BG-2019）为研究对象,通过高精度AMS¹⁴C、OSL定年技术和高分辨率孢粉组合、粒度组分分析,恢复和重建了白洋淀地区晚冰期以来（距今13710 a&#x02014;今）区域植被演替和气候环境变化历史。结果显示：BG-2019剖面在距今10270~13710 a和距今4630~5400 a发育湖相沉积,距今3470~3700 a发育沼泽相沉积;距今7130~8000 a发育河流&#x02014;入湖三角洲相沉积,距今3700~4630 a和距今3230~3470 a发育河流相沉积;距今8000~10270 a和距今5400~7130 a存在明显的沉积间断/地层缺失;表明采样剖面所在位置缺乏连续的湖相地层。晚冰期白洋淀为局地小湖沼;中全新世湖沼较发育、范围广,但也不是连续广袤的湖相沉积;晚全新世湖泊范围收缩。晚冰期和全新世白洋淀流域植被景观存在显著差异;晚冰期气候寒冷干燥,平原发育以蒿属、藜亚科、禾本科和菊科等为主的草地,周围山地森林覆盖度低;中全新世气候温暖湿润,平原大部仍发育以蒿属、藜亚科和禾本科为主的草地,湖区水蕨和水生植物繁盛,周围山地生长松属、栎属为主的针阔混交林,森林覆盖度增高;晚全新世气候温和偏干,平原仍是以蒿属、藜亚科和禾本科等为主的草地,西部山地生长以松属为主的针阔混交林,森林覆盖度较高。

The Yangtze River Valley is an important economic region and one of the cradles of human civilization. It is also the site of frequent floods, droughts, and other natural disasters. Conducting Holocene environmental archaeology research in this region is of great importance when studying the evolution of the relationship between humans and the environment and the interactive effects humans had on the environment from 10.0 to 3.0 ka BP, for which no written records exist. This review provides a comprehensive summary of materials that have been published over the past several decades concerning Holocene environmental archaeology in the Yangtze River Valley, to further understand large-scale regional Holocene environmental and cultural interaction within this area. The results show that: (1) in recent years, Holocene envi-ronmental archaeology research in the Yangtze River Valley has primarily taken paleoflood and sea-level change stratigraphical events to be the foundational threads for study. This began with research on the spatiotemporal distribution of archaeological sites, typical archaeological site stratigraphy, and research on background features concerning environmental evolution recorded by the regional natural sedimentary strata. (2) Significant progress has been made at the upper, middle, and lower reaches of the Yangtze River, indicating that Holocene environmental ar-chaeology research along the Yangtze River Valley is deepening and broadening. (3) Dramatic changes to Neolithic cultures that occurred approximately 4.0 ka BP were influenced by climate change and associated consequences, although the impacts differed on the various Neolithic cultures in the Yangtze River Valley. Local topography, regional climate, and varying survival strategies may have contributed to these differences. (4) Newly-published research pays particular attention to the sedimentary records of the past with resolutions as high as one year to several months, the degree to which humans altered the quality of their natural environment, and human adjustments to settlement and subsistence practices during periods of Holocene climate change. The application of technologies such as remote sensing, geographic information systems (GIS), and molecular biological analysis are also gradually being extended into the research field of Holocene environmental archaeology in the Yangtze River Valley.

During the past few years, an increasing number of studies in both China and abroad have highlighted a long-term warming trend during the Holocene. However, this trend challenges the traditional view of a long-term Holocene cooling trend and a "mid-Holocene Megathermal". Comparison of long-term records indicating a rising global sea level, a decreasing area of terrestrial ice-sheets, and increasing radiative forcings of insolation and GHGs (greenhouse gases) leads us to conclude that a long-term Holocene warming trend is more reasonable than the cooling trend. In the original literature documenting a "mid-Holocene Megathermal" and the subsequent late Holocene cooling trend in China, the uncertainties in the supporting evidence are clearly indicated. These uncertainties have been further demonstrated by recent results that the most significant uncertainty arises from the impacts of human activities on sedimentary proxies, especially in the late Holocene when these impacts were greatly intensified. Thus, reconstructions of late Holocene temperature history based on sedimentary proxies are potentially biased by human impacts. Given that the current debate regarding temperature history of the Holocene focuses on the late Holocene, we propose that future emphasis should be placed on the temperature history of the late Holocene. We suggest that more reliable late Holocene temperature records should come from areas and/or sedimentary proxies that are weakly influenced by human activities, which is especially important to studies on the development of Chinese civilization that lasted for over several millennia. Overall, reliable late Holocene temperature records can potentially provide a reliable foundation for improving our understanding of the following themes: (1) the development of Chinese civilization under the background of long-term temperature change; (2) the evolutionary history of "human-land relationship" during the late Holocene; and (3) the climatic and environmental issues associated with global warming.

最新一些研究结果强调了全新世期间的长期增温趋势,综合全球平均海平面、大陆冰盖面积、大气温室气体和太阳辐射证据来看,这比传统观点所认为的全新世期间的长期降温趋势,更具有合理性。回顾历史,结合最新的一些研究进展,发现支持&#x0201c;中全新世大暖期&#x0201d;和&#x0201c;晚全新世降温趋势&#x0201d;的证据存在明显的不确定性,最核心的问题为晚全新世加强的人类活动对代用指标或者证据的强烈扰动,使得其不能准确地反映真实的气候变化过程。鉴于目前全新世温度历史争论的核心关键在于晚全新世,因此有必要加强晚全新世温度变化研究。在人类活动影响较小的地区,或者利用对人类活动不敏感的代用指标开展研究,有望可以获得更可靠的晚全新世温度历史重建结果,为准确认识中华数千年文明的长期温度变化背景,进而理解期间的&#x0201c;人地关系&#x0201d;演化历史,并最终客观认识现今面临的以全球变暖为主要特征的气候环境问题,提供一定的科学基础。

Seasonal biases (the warm-season contribution) of Holocene mean annual temperature (MAT) reconstructions from geological records were proposed as a possible cause of the mismatch with climate simulated temperature. Here we analyze terrestrial mollusk assemblages that best reflect seasonal signals and provide quantitative MAT and four-season temperature records for northern China during the past 20,000 years. The MAT estimated from the seasonal temperatures of a four-season-mean based on mollusks shows a peak during ~9000-4000 years ago, followed by a cooling trend. In general, the contribution of summer and winter temperature to MAT is significantly greater than that of spring and autumn temperatures. The relative contribution of each season varies over time and corresponds roughly with the seasonal insolation in each season. This independent evidence from mollusk records from the mid-latitudes of East Asia does not support the Holocene long-term warming trend observed in climate simulations and the seasonal bias explanation.© 2022. The Author(s).

The rate of change of climate codetermines the global warming impacts on natural and socioeconomic systems and their capabilities to adapt. Establishing past rates of climate change from temperature proxy data remains difficult given their limited spatiotemporal resolution. In contrast, past greenhouse gas radiative forcing, causing climate to change, is well known from ice cores. We compare rates of change of anthropogenic forcing with rates of natural greenhouse gas forcing since the Last Glacial Maximum and of solar and volcanic forcing of the last millennium. The smoothing of atmospheric variations by the enclosure process of air into ice is computed with a firn diffusion and enclosure model. The 20th century increase in CO(2) and its radiative forcing occurred more than an order of magnitude faster than any sustained change during the past 22,000 years. The average rate of increase in the radiative forcing not just from CO(2) but from the combination of CO(2), CH(4), and N(2)O is larger during the Industrial Era than during any comparable period of at least the past 16,000 years. In addition, the decadal-to-century scale rate of change in anthropogenic forcing is unusually high in the context of the natural forcing variations (solar and volcanoes) of the past millennium. Our analysis implies that global climate change, which is anthropogenic in origin, is progressing at a speed that is unprecedented at least during the last 22,000 years.

The trajectory, pattern, and mechanism of the human-land co-evolution process is a critical issue in the field of human geography. The pattern of human-environment interaction has varied significantly during different phases of human evolution, suggesting a series of changes in the driving force of human-land co-evolution. Although a variety of underlying mechanisms specific to the key periods of human history (e.g., Paleolithic, Neolithic, Bronze, and historical ages) have been intensively investigated, there are still significant gaps in the widely accepted model of the fundamental law that governs human-land co-evolution across human history. In this paper we propose the Fulcrum Cognitive Model (FCM), with the objective of disentangling the mechanism of human-land co-evolution. The FCM focuses on the equilibrium between the natural ecosystem and human social system, which can be disturbed by both climatic/environmental change and human activities, and restored by an adjustment of the human social system. Moreover, we propose a "quantitative-change equilibrium pattern" and "qualitative-change equilibrium pattern" on the basis of FCM, to further describe the mechanism of past human-land co-evolution in different contexts. In the former pattern, a new equilibrium between the natural ecosystem and human social system is rebuilt by the corresponding changes in population size, without a shift in the fulcrum position. In contrast, in the latter pattern, societies improve their social resilience to the deterioration of the living environment through social and/or technological changes. In this case, the fulcrum position of the original equilibrium shifts and the pattern of human-environment interaction is transformed. Social resilience is gradually strengthened during the evolutionary process and the dominant influencing factor moves from natural causes towards anthropogenic factors. To test its feasibility, we applied the model to the changing patterns of the human-land relationship in Shanxi, Shaanxi, and Henan provinces in central north China between the Yangshao period (~5000-3000 BCE) and Zhou Dynasty (1046-256 BCE), based on a comprehensive analysis of updated archaeological and paleoclimatic data. The results suggested that the mechanism controlling the human-land relationship during ~4000-2600 BCE and 2600-256 BCE could be explained by the "quantitative-change equilibrium pattern" and "qualitative-change equilibrium pattern", respectively. The mechanism of human-land co-evolution in the past is very complicated and the interaction of these two patterns may vary in terms of its spatiotemporal scale, which will require further study in the future.

人地关系演变的历史、规律和机制是地理学研究的重要科学问题。在人类社会演化的不同阶段,人与环境相互作用的模式存在显著差异,揭示人地关系在时间维度上的演变轨迹和机制可为有效衔接古今人地关系研究提供重要依据。基于对过去人地关系研究案例的分析和总结,我们提出“支点”概念模型尝试解释人地关系演变的规律和机制。当特定区域人口数量增长到一定程度时,自然生态系统和人类社会系统达到平衡状态,随后的气候环境变化和人类活动变化都有可能打破其平衡状态。人类社会系统在面对生存环境变化压力时可能出现两种不同方式的响应：① 通过人口数量的调节适应生存环境变化而达到新的平衡,其特点是人与环境相互作用的模式（人类社会与自然生态系统平衡“支点”位置）不变;② 通过人类社会组织结构或技术革新方式使社会适应生存环境变化的“韧性”增强,体现为人与环境相互作用模式发生改变。随着时间的推移,社会韧性呈增强趋势,人地关系演变的主导因素也整体呈现由自然因素向人为因素的偏移。最后,以河南、山西和陕西三省仰韶文化时期（约公元前5000—公元前3000年）至周代（公元前1046—公元前256年）的人地关系研究为例,运用“支点”概念模型分析了其演变机制。

The history of fruit-tree utilization by prehistoric people has become an important issue that has attracted increasing attention in recent years. However, the question of how people used fruit trees has not yet been answered; in particular, the impacts of different subsistence strategies on human behavior regarding fruit-tree utilization (wild gathering or conscious cultivation) have not yet been considered. Here, we present the results of charcoal identification of fruit trees from 16 dated archeological sites in the northeastern Tibetan Plateau (NETP) spanning the period c. 5,200–2,600 BP. We combine this with reported multidisciplinary evidence to explore the history of fruit-tree utilization as well as its relation to the subsistence strategy in the NETP during the late Neolithic and Bronze Age. Our results demonstrate that Rosaceae [Prunus L., Prunus Padus L., Maloideae L., and Malus baccata (L.) Borkh], Elaeagnaceae (Hippophae L. and Elaeagnus angustifolia L.), and Rhamnaceae (only Ziziphus Mill.) were used by people in the NETP, and there was a downward trend in the use of fruit trees during the late Neolithic and Bronze Age. This is in notable contrast to the situation in the Chinese Loess Plateau in the parallel period. The cold-dry climate during the Bronze Age seemed to be one of the reasons. The fruit trees used by people in the NETP were likely gathered from the wild rather than consciously cultivated, and the subsistence strategy of agropastoralism may have played a significant role during the processes.