The Jiangchuan Biota from the Jiucheng Member(Mb.)of the Dengying Formation(Fm.),discovered in Jiangchuan,eastern Yunnan,China,is marked by copious macrofossils at the apex of the Ediacaran strata.This fauna features ...The Jiangchuan Biota from the Jiucheng Member(Mb.)of the Dengying Formation(Fm.),discovered in Jiangchuan,eastern Yunnan,China,is marked by copious macrofossils at the apex of the Ediacaran strata.This fauna features benthic algae with varied holdfasts and other fossils of indeterminate taxonomic affinity and is compositionally unique compared to the Shibantan and Gaojiashan biotas of the Dengying Fm.and the Miaohe and Wenghui biotas of the Doushantuo Fm.,elsewhere in China.One novel benthic saccular macroalgal fossil,named here Houjiashania yuxiensis gen.and sp.nov.,from the Jiangchuan Biota is based on fossils that are sausage-shaped,elongate,tubular,ranging from 0.3 to 4 cm in length,and up to 0.8 cm in diameter.One terminus is blunt and rounded to an obtuse angle,the other is bent with a spread-out surface resembling a holdfast,suggesting a three-dimensional thallus.Thin,stipe-shaped outgrowths,likely vestiges of sessile saccular life forms,are prevalent in macroalgal fossils of analogous size and shape,as well as present brown algae Scytosiphonaceae,such as Colpomenia and Dactylosiphon.The new findings augment the diversity of benthic algae,such as those known from the Early Neoproterozoic Longfengshan Biota in North China.The benthic algal macrofossils in the Jiucheng Mb.add to knowledge of Late Ediacaran metaphyte diversification and offer more clues about the evolutionary positioning of primitive macroalgae.The co-occurrence of numerous planktonic and benthic multicellular algae and planktonic microbes might have facilitated ecologically the more extensive later Cambrian explosion evidenced by the Chengjiang Biota in Yunnan.展开更多
为优化江川区土地利用空间格局,促进土地可持续发展,该文以云南省玉溪市江川区为研究区,将CLUE-S(conversion of land use and its effects at small region extent)模型和生态敏感性分析应用于江川区土地利用空间格局优化配置。以高度...为优化江川区土地利用空间格局,促进土地可持续发展,该文以云南省玉溪市江川区为研究区,将CLUE-S(conversion of land use and its effects at small region extent)模型和生态敏感性分析应用于江川区土地利用空间格局优化配置。以高度敏感区为CLUE-S模型中区域约束文件,突出研究区生态保护重点区域,并以综合生态敏感性分区为影响研究区土地利用变化的驱动力因子,提出一种将生态敏感性融入土地利用空间格局优化配置的过程和结果中的土地利用情景模拟方法,并借助2006年和2016年土地利用数据对江川区自然发展情景和土地生态优化情景2种模式下2025年的土地利用空间格局进行优化配置,并基于生态敏感性分区对优化配置模拟结果进行对比分析。结果表明:2种情景下2025年江川区土地利用格局既有共同特征也存在差异。在2种情景下均有效的保护了原有林地、耕地、未利用地和建设用地格局,但新增林地、草地等空间分布格局不同。根据2025年2种情景与2016年土地利用现状在不同敏感性区内主要土地利用类型分布情况表明,情景二土地利用空间格局优于自然发展情景和2016年土地利用现状。研究结果认为土地生态优化情景更为合理,该结果可为江川区生态保护和城镇发展提供参考。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42172035,42062005 and 41572024)the China Geological Survey(Grant No.DD20221648)+1 种基金Yunnan Province Science and Technology Department(Grant No.202305AD160031,202401AT070012)the project entitled 1:50000 Regional Geological Survey of Dazhuang,Fabiao,Ditu,and Dianzhong Sheets in Yunnan Province(Grant No.D202207).
文摘The Jiangchuan Biota from the Jiucheng Member(Mb.)of the Dengying Formation(Fm.),discovered in Jiangchuan,eastern Yunnan,China,is marked by copious macrofossils at the apex of the Ediacaran strata.This fauna features benthic algae with varied holdfasts and other fossils of indeterminate taxonomic affinity and is compositionally unique compared to the Shibantan and Gaojiashan biotas of the Dengying Fm.and the Miaohe and Wenghui biotas of the Doushantuo Fm.,elsewhere in China.One novel benthic saccular macroalgal fossil,named here Houjiashania yuxiensis gen.and sp.nov.,from the Jiangchuan Biota is based on fossils that are sausage-shaped,elongate,tubular,ranging from 0.3 to 4 cm in length,and up to 0.8 cm in diameter.One terminus is blunt and rounded to an obtuse angle,the other is bent with a spread-out surface resembling a holdfast,suggesting a three-dimensional thallus.Thin,stipe-shaped outgrowths,likely vestiges of sessile saccular life forms,are prevalent in macroalgal fossils of analogous size and shape,as well as present brown algae Scytosiphonaceae,such as Colpomenia and Dactylosiphon.The new findings augment the diversity of benthic algae,such as those known from the Early Neoproterozoic Longfengshan Biota in North China.The benthic algal macrofossils in the Jiucheng Mb.add to knowledge of Late Ediacaran metaphyte diversification and offer more clues about the evolutionary positioning of primitive macroalgae.The co-occurrence of numerous planktonic and benthic multicellular algae and planktonic microbes might have facilitated ecologically the more extensive later Cambrian explosion evidenced by the Chengjiang Biota in Yunnan.
文摘为优化江川区土地利用空间格局,促进土地可持续发展,该文以云南省玉溪市江川区为研究区,将CLUE-S(conversion of land use and its effects at small region extent)模型和生态敏感性分析应用于江川区土地利用空间格局优化配置。以高度敏感区为CLUE-S模型中区域约束文件,突出研究区生态保护重点区域,并以综合生态敏感性分区为影响研究区土地利用变化的驱动力因子,提出一种将生态敏感性融入土地利用空间格局优化配置的过程和结果中的土地利用情景模拟方法,并借助2006年和2016年土地利用数据对江川区自然发展情景和土地生态优化情景2种模式下2025年的土地利用空间格局进行优化配置,并基于生态敏感性分区对优化配置模拟结果进行对比分析。结果表明:2种情景下2025年江川区土地利用格局既有共同特征也存在差异。在2种情景下均有效的保护了原有林地、耕地、未利用地和建设用地格局,但新增林地、草地等空间分布格局不同。根据2025年2种情景与2016年土地利用现状在不同敏感性区内主要土地利用类型分布情况表明,情景二土地利用空间格局优于自然发展情景和2016年土地利用现状。研究结果认为土地生态优化情景更为合理,该结果可为江川区生态保护和城镇发展提供参考。
