Phytoliths are noncrystalline minerals that form inside cells and cell walls of different parts of plants. Organic carbon in living cells can be occluded in phytoliths during plant growth. It has been documented that ...Phytoliths are noncrystalline minerals that form inside cells and cell walls of different parts of plants. Organic carbon in living cells can be occluded in phytoliths during plant growth. It has been documented that the occluded carbon within phytoliths is an important long-term terrestrial carbon reservoir that has a major role in the global carbon cycle. Common millet and foxtail millet have become typical dry-farming crops in China since the Neolithic Age. The study of carbon conservation within phytoliths in these crops could provide insights into anthropogenic influences on the carbon cycle. In this study, we analyzed the carbon content in phytoliths of common millet and foxtail millet. The results indicated that (1) common millet and foxtail millet contained 0.136% ± 0.070% and 0.129% ± 0.085% phytolith-occluded carbon (PhytOC) on a dry mass basis, respectively; (2) based on the mean annual production of common millet and foxtail millet in the last 10 years, the phytolith occluded carbon accumulation rate of common millet and foxtail millet was approximately 0.023 ± 0.015 and 0.020 ± 0.010 t CO 2 ha 1 a 1 , respectively; (3) assuming a similar phytolith occluded carbon accumulation rate as for common millet (the highest accumulation rate was 0.038 t CO 2 ha 1 a 1 ), this could result in the sequestration of 2.37 × 10 6 t CO 2 per year for the 62.4 × 10 6 ha dry-farming crops in China. Although there was a decline in the annual production rate and planting area of foxtail millet during 1949 to 2008, the total phytolith carbon sequestration rate was 7×10 6 t CO 2 within the 60-year period. However, phytolith occluded carbon has not yet been fully considered as a global carbon sink. Also, this carbon fraction is probably one of the best candidates for the missing carbon sink.展开更多
在嘉兴杭嘉湖平原实验基地,以嘉花11、浙粳37、宁81、祥湖301、秀水09等5个品种水稻及其0—10cm表层土壤为研究对象,运用微波消解和Walkley-Black的方法,研究了稻田生态系统中植硅体的产生和积累通量,为了解植硅体在稻田生态系统硅和碳...在嘉兴杭嘉湖平原实验基地,以嘉花11、浙粳37、宁81、祥湖301、秀水09等5个品种水稻及其0—10cm表层土壤为研究对象,运用微波消解和Walkley-Black的方法,研究了稻田生态系统中植硅体的产生和积累通量,为了解植硅体在稻田生态系统硅和碳生物地球化学循环中的作用提供科学参考。结果表明:(1)植硅体含量在不同品种水稻中嘉花11、宁81和祥湖301高于浙粳37和秀水09,在各器官中鞘>叶>茎>根>穗;(2)水稻植株植硅体产生通量为1269.59 kg hm-2a-1,其中地上部分为1203.44 kg hm-2a-1,地下部分为66.15 kg hm-2a-1,在种植50a的稻田0—10cm土壤中的积累通量为40.38 kg hm-2a-1;(3)选择嘉花11等高植硅体含量品种进行推广种植,对提高水稻植硅体产生通量及其包裹大气中CO2通量有很大的作用。展开更多
A study on phytoliths and their climate indexes is carried out from Homo erectus?cave deposits in HuluCave, Nanjing. Evidence shows that phytolith assemblages of the cave deposits are dominated by the cold resistant t...A study on phytoliths and their climate indexes is carried out from Homo erectus?cave deposits in HuluCave, Nanjing. Evidence shows that phytolith assemblages of the cave deposits are dominated by the cold resistant types with a lower warm index, reflecting an overall cold inclined climate. This possibly connects the cave deposits with glacial climate to a great extent, which is in accordance with thenorthern fauna revealed by fossil mammals and temperateclimate indicated by pollen assemblages. According to the distributional state of the phytoliths and their climate in-dexes on 4 profiles in the cave, it is revealed that profiles Ⅰand Ⅱ display certain cold/warm, and dry/wet fluctuations; profile Ⅲ shows a humid and cold condition with the high-est humility in the cave deposits; while profile Ⅳ indicates a possible quick accumulating process because of its stableclimate indexes except for its bottom and top.展开更多
以浙江慈溪滨海沉积物上发育的5个具有不同植稻年龄的水耕人为土剖面为研究对象,系统分析了土壤中的植硅体及其闭留碳的演变特征。结果表明,水耕人为土时间序列土壤中植硅体的含量变幅为3.67~17.51 g kg-1。水耕人为土中植硅体的剖面分...以浙江慈溪滨海沉积物上发育的5个具有不同植稻年龄的水耕人为土剖面为研究对象,系统分析了土壤中的植硅体及其闭留碳的演变特征。结果表明,水耕人为土时间序列土壤中植硅体的含量变幅为3.67~17.51 g kg-1。水耕人为土中植硅体的剖面分布特征与有机碳相似,呈现出随着土壤深度的增加含量逐渐降低的趋势。其剖面分布特征表明植硅体在水耕人为土中不易移动。与起源土相比,水耕人为土表层植硅体含量有较大程度的增加,说明植稻有利于植硅体在土壤表层富集。而植硅体随植稻年龄的增加没有表现出有规律的增加或减少趋势。统计分析表明植硅体和总硅之间呈极显著正相关,说明植硅体对土壤发生中的硅循环起着重要作用。水稻产生的植硅体其体内闭留的碳量较高,但由于土体内植硅体总量较低,植硅体闭留碳仅占总有机碳的0.93%~1.68%。现有数据表明,仅通过根系与残茬返还土壤,种植富硅植物水稻并不能显著增强土壤的长期固碳能力。由于植硅体固定的碳在土壤环境中比较稳定,如果能强化秸秆还田,植稻对于土壤长期固碳具有意义。展开更多
China is one of the main global centers of origin of agriculture. Foxtail millet(Setaria italica), common millet(Panicum miliaceum), and rice(Oryza sativa) were the first crops to be domesticated in China. There remai...China is one of the main global centers of origin of agriculture. Foxtail millet(Setaria italica), common millet(Panicum miliaceum), and rice(Oryza sativa) were the first crops to be domesticated in China. There remain many uncertainties and controversies in our current understanding of the chronology, locations, and plant types at the origins and the process of evolution of prehistoric millet and rice farming, and their relationships with climate change and human adaptation. This review summarizes the research progress made by Chinese scientists over the last decade on the origins and evolution of prehistoric agriculture. It highlights novel techniques and methods for identifying early crop remains, including plant macrofossils(carbonized seeds, spikelets), microfossils(phytoliths, calciphytoliths, starch, pollen), and biomarkers; new evidence on the origins, development, and spread of early agriculture; and research related to climate and environmental changes. Further, we pinpoint and discuss existing challenges and potential opportunities for further in-depth investigation of the origins and evolution of agriculture and the adaption of human activities to climate change.展开更多
The analysis of carbon isotope in phytoliths from modern plants and surface soils in China shows that the values of carbon isotope are consistent with those from C3 and C4 plants, and the processes of photosynthesis o...The analysis of carbon isotope in phytoliths from modern plants and surface soils in China shows that the values of carbon isotope are consistent with those from C3 and C4 plants, and the processes of photosynthesis of the original plants can be clearly identified by carbon isotope in phytoliths. The value of carbon isotope varied from -23.8‰ to -28‰, with the maximum distributed in the latitude zone from 34°N to 40°N in North China and East China areas, and the minimum in the Northeast China and South China regions. The values of carbon of phytoliths tend to increase from low to high and then reduce to low value again as the latitude increases. In the same latitude zone, the carbon isotope in phytoliths from grassland soil under the trees is obviously lower than that from grassland soil without any trees with the difference of 1‰ - 2‰.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05130602)the National Natural Science Foundation of China (4107113)
文摘Phytoliths are noncrystalline minerals that form inside cells and cell walls of different parts of plants. Organic carbon in living cells can be occluded in phytoliths during plant growth. It has been documented that the occluded carbon within phytoliths is an important long-term terrestrial carbon reservoir that has a major role in the global carbon cycle. Common millet and foxtail millet have become typical dry-farming crops in China since the Neolithic Age. The study of carbon conservation within phytoliths in these crops could provide insights into anthropogenic influences on the carbon cycle. In this study, we analyzed the carbon content in phytoliths of common millet and foxtail millet. The results indicated that (1) common millet and foxtail millet contained 0.136% ± 0.070% and 0.129% ± 0.085% phytolith-occluded carbon (PhytOC) on a dry mass basis, respectively; (2) based on the mean annual production of common millet and foxtail millet in the last 10 years, the phytolith occluded carbon accumulation rate of common millet and foxtail millet was approximately 0.023 ± 0.015 and 0.020 ± 0.010 t CO 2 ha 1 a 1 , respectively; (3) assuming a similar phytolith occluded carbon accumulation rate as for common millet (the highest accumulation rate was 0.038 t CO 2 ha 1 a 1 ), this could result in the sequestration of 2.37 × 10 6 t CO 2 per year for the 62.4 × 10 6 ha dry-farming crops in China. Although there was a decline in the annual production rate and planting area of foxtail millet during 1949 to 2008, the total phytolith carbon sequestration rate was 7×10 6 t CO 2 within the 60-year period. However, phytolith occluded carbon has not yet been fully considered as a global carbon sink. Also, this carbon fraction is probably one of the best candidates for the missing carbon sink.
文摘在嘉兴杭嘉湖平原实验基地,以嘉花11、浙粳37、宁81、祥湖301、秀水09等5个品种水稻及其0—10cm表层土壤为研究对象,运用微波消解和Walkley-Black的方法,研究了稻田生态系统中植硅体的产生和积累通量,为了解植硅体在稻田生态系统硅和碳生物地球化学循环中的作用提供科学参考。结果表明:(1)植硅体含量在不同品种水稻中嘉花11、宁81和祥湖301高于浙粳37和秀水09,在各器官中鞘>叶>茎>根>穗;(2)水稻植株植硅体产生通量为1269.59 kg hm-2a-1,其中地上部分为1203.44 kg hm-2a-1,地下部分为66.15 kg hm-2a-1,在种植50a的稻田0—10cm土壤中的积累通量为40.38 kg hm-2a-1;(3)选择嘉花11等高植硅体含量品种进行推广种植,对提高水稻植硅体产生通量及其包裹大气中CO2通量有很大的作用。
文摘A study on phytoliths and their climate indexes is carried out from Homo erectus?cave deposits in HuluCave, Nanjing. Evidence shows that phytolith assemblages of the cave deposits are dominated by the cold resistant types with a lower warm index, reflecting an overall cold inclined climate. This possibly connects the cave deposits with glacial climate to a great extent, which is in accordance with thenorthern fauna revealed by fossil mammals and temperateclimate indicated by pollen assemblages. According to the distributional state of the phytoliths and their climate in-dexes on 4 profiles in the cave, it is revealed that profiles Ⅰand Ⅱ display certain cold/warm, and dry/wet fluctuations; profile Ⅲ shows a humid and cold condition with the high-est humility in the cave deposits; while profile Ⅳ indicates a possible quick accumulating process because of its stableclimate indexes except for its bottom and top.
文摘以浙江慈溪滨海沉积物上发育的5个具有不同植稻年龄的水耕人为土剖面为研究对象,系统分析了土壤中的植硅体及其闭留碳的演变特征。结果表明,水耕人为土时间序列土壤中植硅体的含量变幅为3.67~17.51 g kg-1。水耕人为土中植硅体的剖面分布特征与有机碳相似,呈现出随着土壤深度的增加含量逐渐降低的趋势。其剖面分布特征表明植硅体在水耕人为土中不易移动。与起源土相比,水耕人为土表层植硅体含量有较大程度的增加,说明植稻有利于植硅体在土壤表层富集。而植硅体随植稻年龄的增加没有表现出有规律的增加或减少趋势。统计分析表明植硅体和总硅之间呈极显著正相关,说明植硅体对土壤发生中的硅循环起着重要作用。水稻产生的植硅体其体内闭留的碳量较高,但由于土体内植硅体总量较低,植硅体闭留碳仅占总有机碳的0.93%~1.68%。现有数据表明,仅通过根系与残茬返还土壤,种植富硅植物水稻并不能显著增强土壤的长期固碳能力。由于植硅体固定的碳在土壤环境中比较稳定,如果能强化秸秆还田,植稻对于土壤长期固碳具有意义。
基金supported by the National Natural Science Foundation of China(Grant No.41230104)the National Basic Research Program of China(Grant No.2015CB953801)+1 种基金the“Strategic Priority Research Program:Climate Change,Carbon Budget and Relevant Issues”of the Chinese Academy of Sciences(Grant No.XDA05130602)the“Macroevolutionary Processes and Paleoenvironments of Major Historical Biota”of the Chinese Academy of Sciences(Grant No.XDPB0503)
文摘China is one of the main global centers of origin of agriculture. Foxtail millet(Setaria italica), common millet(Panicum miliaceum), and rice(Oryza sativa) were the first crops to be domesticated in China. There remain many uncertainties and controversies in our current understanding of the chronology, locations, and plant types at the origins and the process of evolution of prehistoric millet and rice farming, and their relationships with climate change and human adaptation. This review summarizes the research progress made by Chinese scientists over the last decade on the origins and evolution of prehistoric agriculture. It highlights novel techniques and methods for identifying early crop remains, including plant macrofossils(carbonized seeds, spikelets), microfossils(phytoliths, calciphytoliths, starch, pollen), and biomarkers; new evidence on the origins, development, and spread of early agriculture; and research related to climate and environmental changes. Further, we pinpoint and discuss existing challenges and potential opportunities for further in-depth investigation of the origins and evolution of agriculture and the adaption of human activities to climate change.
文摘The analysis of carbon isotope in phytoliths from modern plants and surface soils in China shows that the values of carbon isotope are consistent with those from C3 and C4 plants, and the processes of photosynthesis of the original plants can be clearly identified by carbon isotope in phytoliths. The value of carbon isotope varied from -23.8‰ to -28‰, with the maximum distributed in the latitude zone from 34°N to 40°N in North China and East China areas, and the minimum in the Northeast China and South China regions. The values of carbon of phytoliths tend to increase from low to high and then reduce to low value again as the latitude increases. In the same latitude zone, the carbon isotope in phytoliths from grassland soil under the trees is obviously lower than that from grassland soil without any trees with the difference of 1‰ - 2‰.
