scholarly journals Phytolith records of flourishing early Holocene Pooideae linked to an 8.2 ka cold event in subtropical China

Elem Sci Anth ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Xinxin Zuo ◽  
Houyuan Lu ◽  
Zhen Li ◽  
Bing Song ◽  
Deke Xu ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Asian Monsoon ◽  
Early Holocene ◽  
Subtropical China ◽  
Cold Event ◽  
Ecological Zones ◽  
Lower Yangtze Region ◽  
Dry Conditions ◽  
Lower Yangtze

The grass subfamily Pooideae originated in a temperate niche during the late Cretaceous; it is the largest Poaceae subfamily, consisting of almost 4,000 species, which are distributed worldwide. Pooideae responses to climate changes at different time scales, and different ecological zones are thus important in understanding Poaceae evolutionary processes and their relationship with climate change. In the study described in this article, we reconstructed Pooideae variability during the early Holocene, as inferred by a phytolith sequence from the Lower Yangtze in subtropical China. The phytolith assemblage was marked by three increases in Pooideae phytoliths, dated to ca 8.4–8.0, 7.8–7.6, and 7.4–7.2 ka BP (before present, 1950 AD), with each representing pronounced increases in Pooideae extent and distribution. All these increases were within age ranges that agreed well with the timing of weak Asian Monsoon events, at 8.2, 7.7, and 7.3 ka BP. The first Pooideae flourishing period in subtropical China was the most significant, lasting for approximately four centuries and being characterized by a double peak, which equated with an event at 8.2 ka. This suggested that cold and/or dry conditions—which occurred over a period of several hundred years and were linked to weakening of the Asian monsoon—probably caused Pooideae to flourish in the Lower Yangtze region. Comparison of two diagnostic trapezoid phytolith types—namely wavy and wavy narrow—which showed different changes between ca 8.4 and 8.0 ka BP, suggested that they responded differently to the climate change represented by the 8.2 ka event. Our phytolith records have provided not only new data clarifying the detailed Pooideae response to the 8.2 ka event but also a reliable index for past cold climates in subtropical China.

scholarly journals IMPACT OF CLIMATIC PARAMETERS ON CROP WATER REQUIREMENTS IN DIFFERENT AGRO ECOLOGICAL ZONES OF PAKISTAN

2020 ◽  
Vol 4 (1) ◽  
pp. 21-24
Author(s):  
Imran Shaukat ◽  
Hafiz Ihsan -ul-Haq ◽  
Hafiz M. Safdar ◽  
Rao Husnain Arshad
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Global Scale ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Climatic Parameters ◽  
Crop Water ◽  
Ecological Zones ◽  
Anthropogenic Processes ◽  
Agro Ecological Zones

The problem of climate change has become very strongly during last two decades on global scale in view of the projected consequences on the environment of unguarded states. Gradually rising temperature and its effects on the crops here and rainfall are obvious in many areas around the world. Climate change related to natural and anthropogenic processes in Pakistan is the major source of study in this report. The impacts of these climate changes appear to be additional component of the large number of existing water related problems in every station of Pakistan. The objective of this report is to analyze the global warming effect on CWR. For this purpose, we made seven scenarios So, S1, S2, S3, S4, S5 and S6. From So-S3 crop water requirement increases in all regions but from S4-S6 crop water requirement remains same. For this purpose we selected different cities from agro ecological stations to check the effect of climate change on CWR. Faisalabad, Gupis, Jacobabad, Kalat, Karachi, Multan, Nawabshah, Peshawar and Zhob are the regions selected for this research. Different scenarios have been made such that, in So scenario temperature remains same but from S1, S2 and S3 scenarios temperature is increases 1, 2 and 3 degree centigrade respectively. While, in S4, S5 and S6 scenarios precipitation increases or decreases according to the climatic changes of that area (So, S1, S2, S3, ) and then we increase or decrease the precipitation rate by 5%, 10% and 15% (S4, S5, S6) in accordance with the zone. From result it is concluded that the crop water requirement in arid and in semi-arid is increasing annually on the other hand the total value of effective rainfall in Pakistan is decreasing.

A multi-proxy lacustrine record of last deglacial–early Holocene environmental variability in the lower Yangtze region from the Chaohu Lake Basin, eastern China

2017 ◽  
Vol 88 (3) ◽  
pp. 446-457 ◽  
Author(s):  
Houchun Guan ◽  
Li Wu ◽  
Jinzhe Zhang ◽  
Shihao Shen ◽  
Dongru Chu ◽  
...  
Keyword(s):  
Lacustrine Sediments ◽  
Cold Climate ◽  
Early Holocene ◽  
Chaohu Lake ◽  
Lake Basin ◽  
Chaohu Lake Basin ◽  
Lower Yangtze Region ◽  
Lower Yangtze ◽  
The Chaohu Lake Basin ◽  
Last Deglacial

AbstractThe Rb, Sr, and Ti content, Rb/Sr ratio, grain size, magnetic susceptibility, and magnetic fabric in sediments of the BZK1 core were utilized to reconstruct the evolution of the climatic environment in the Chaohu Lake Basin between the last deglacial and the early Holocene. Multi-proxy analyses indicate that lacustrine sediments in Chaohu Lake clearly record the Bølling-Allerød interstadial, the Younger Dryas event and dry-cold climate events occurring between 10.7 cal ka BP and 10.5 cal ka BP. At approximately 15.6–14.8 cal ka BP, the waters became deeper and the climate turned cool. The climate subsequently shifted to a relatively humid period and the lake was largest from 14.8 to 12.8 cal ka BP. From 12.8 to 11.7 cal ka BP, the climate abruptly turned dry and cold and the lake shrank to its lowest level. During 11.7–10.7 cal ka BP, the climate became relatively humid but, from approximately 10.7 to 10.5 cal ka BP, suddenly reverted to a dry and cold state. These climatic change records suggest that lacustrine sediments from the Chaohu Lake Basin in the lower Yangtze region responded actively to global climate changes, comparable with the environmental records from stalagmites and other lacustrine sediments in the region.

scholarly journals Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze region in response to climate change

2021 ◽  
Vol 7 (48) ◽  
Author(s):  
Haiwei Zhang ◽  
Hai Cheng ◽  
Ashish Sinha ◽  
Christoph Spötl ◽  
Yanjun Cai ◽  
...  
Keyword(s):  
Climate Change ◽  
Lower Yangtze Region ◽  
Lower Yangtze ◽  
Neolithic Cultures

scholarly journals Using expert elicitation to strengthen future regional climate information for climate services

2021 ◽  
Author(s):  
Sam Grainger ◽  
Suraje Dessai ◽  
Joseph Daron ◽  
Andrea Taylor ◽  
Yim Ling Siu
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Expert Elicitation ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Services ◽  
Couple Model Intercomparison Project ◽  
Lower Yangtze Region ◽  
Lower Yangtze ◽  
Lines Of Evidence

<p>Climate change knowledge can inform regional and local adaptation decisions. However, estimates of future climate are uncertain and methods for assessing uncertainties typically rely on the results of climate model simulations, which are constrained by the quality of assumptions used in model experiments and the limitations of available models. To strengthen knowledge for adaptation decisions, we use structured expert elicitation to assess future climate change in the Lower Yangtze region in China. We elicit judgements on future changes in temperature and precipitation as well as uncertainty sources, comparing elicited judgements and model outputs from phase 5 of the Couple Model Intercomparison Project (CMIP5). We find high consensus amongst experts that the Lower Yangtze region will be warmer in the coming decades, albeit with differences in the magnitude of change. There is less consensus around the direction and magnitude of change for future precipitation change in the region. When compared with CMIP5 model outputs, experts provide similar or narrower uncertainty ranges for temperature change and diverse ranges for precipitation. Experts considered additional factors (e.g. model credibility, observations, theory and paleo-climatic evidence) and uncertainties not usually represented in conventional modelling approaches. We explore the value in bringing together multiple lines of evidence in the context of climate services, arguing that while decision makers should not rely solely on expert judgements, this information can complement model information to strengthen regional climate change knowledge. These multiple lines of evidence can help in building dialogue between climate experts and regional stakeholders, contributing to the development of climate services. </p>

Spatial and temporal pattern of rice domestication during the early Holocene in the lower Yangtze region, China

The Holocene ◽  
2021 ◽  
pp. 095968362110190
Author(s):  
Xiujia Huan ◽  
Houyuan Lu ◽  
Leping Jiang ◽  
Xinxin Zuo ◽  
Keyang He ◽  
...  
Keyword(s):  
Temporal Pattern ◽  
Early Stage ◽  
Early Holocene ◽  
Crop Domestication ◽  
Spatial And Temporal Patterns ◽  
Cultural Sites ◽  
Lower Yangtze Region ◽  
Domestication Process ◽  
Lower Yangtze ◽  
Rice Domestication

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.

Comparative Analysis of The Role of Gender in Climate Change Adaptation Between Kajiado And Kiambu County, Kenya

2019 ◽  
pp. 28-37
Author(s):  
Abdimajid Nunow ◽  
Nzioka J. Muthama ◽  
Ininda J. Mwalichi ◽  
Kinama Josiah
Keyword(s):  
Climate Change ◽  
Comparative Analysis ◽  
Random Sampling ◽  
Climate Adaptation ◽  
Gender Disparity ◽  
Adaptation To Climate Change ◽  
Resource Base ◽  
Climatic Zones ◽  
Ecological Zones ◽  
Dry Conditions

Many studies on adaptation to a changing climate have been undertaken across the world Kenya included. However, comparative analysis of gender in relationship to climate adaptation is poorly documented. This study therefore investigated how gender impacts community based adaptation to climate change in Kajiado County, representing mainly pastoral/ASAL regions of Kenya characterized by dry conditions and falling between agro climatic zones IV-VII and Kiambu County, representing mainly farming/highland regions of Kenya characterized by wet conditions and falling under agro climatic zones of between I-III. The study applied systematic random sampling to identify 312 households for interviews. Purposive random sampling was applied where fourteen key informant interviews were done together with six Focus Group Discussions involving three groups of men only, women only and inclusive one to verify information from the individual interviews within the selected communities. The results are comparative analysis of how communities in two different agro-ecological zones (AEZs) adapted to climate change coupled with declining resource base while operating on unequal gender dynamics. The assumption of the study was change in climate in Kajiado and Kiambu County would lead to increased food insecurity and gender disparity. Respondents from both Counties experienced increased drought periods, reduced rainfall patterns thus negatively impacting their livelihood sources. However, there is more gender disparity in Kajiado than Kiambu and also climate change has execrated the situation thus undermining efforts toward food security.

Climate-induced treeline mortality during the termination of the Little Ice Age in the Greater Yellowstone Ecoregion, USA

The Holocene ◽  
2021 ◽  
pp. 095968362110116
Author(s):  
Maegen L Rochner ◽  
Karen J Heeter ◽  
Grant L Harley ◽  
Matthew F Bekker ◽  
Sally P Horn
Keyword(s):  
Climate Change ◽  
Tree Ring ◽  
Little Ice Age ◽  
Climate Changes ◽  
Frost Damage ◽  
Ice Age ◽  
Spatial And Temporal Variability ◽  
Whitebark Pine ◽  
Engelmann Spruce ◽  
Greater Yellowstone

Paleoclimate reconstructions for the western US show spatial variability in the timing, duration, and magnitude of climate changes within the Medieval Climate Anomaly (MCA, ca. 900–1350 CE) and Little Ice Age (LIA, ca. 1350–1850 CE), indicating that additional data are needed to more completely characterize late-Holocene climate change in the region. Here, we use dendrochronology to investigate how climate changes during the MCA and LIA affected a treeline, whitebark pine ( Pinus albicaulis Engelm.) ecosystem in the Greater Yellowstone Ecoregion (GYE). We present two new millennial-length tree-ring chronologies and multiple lines of tree-ring evidence from living and remnant whitebark pine and Engelmann spruce ( Picea engelmannii Parry ex. Engelm.) trees, including patterns of establishment and mortality; changes in tree growth; frost rings; and blue-intensity-based, reconstructed summer temperatures, to highlight the terminus of the LIA as one of the coldest periods of the last millennium for the GYE. Patterns of tree establishment and mortality indicate conditions favorable to recruitment during the latter half of the MCA and climate-induced mortality of trees during the middle-to-late LIA. These patterns correspond with decreased growth, frost damage, and reconstructed cooler temperature anomalies for the 1800–1850 CE period. Results provide important insight into how past climate change affected important GYE ecosystems and highlight the value of using multiple lines of proxy evidence, along with climate reconstructions of high spatial resolution, to better describe spatial and temporal variability in MCA and LIA climate and the ecological influence of climate change.

scholarly journals Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nabaz R. Khwarahm
Keyword(s):  
Climate Change ◽  
Habitat Suitability ◽  
Environmental Variables ◽  
Climate Changes ◽  
Future Climate ◽  
Annual Precipitation ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Kurdistan Region ◽  
Oak Tree

Abstract Background The oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables. Results The model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes. Conclusions The results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

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