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湖南八面山银杉群落特征及其残遗性和保守性分析 被引量:7
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作者 苏乐怡 赵万义 +4 位作者 张记军 杨玉鹏 郭远飞 凡强 廖文波 《植物资源与环境学报》 CAS CSCD 北大核心 2016年第4期76-86,共11页
为了解中国特有孑遗植物银杉(CathayaargyrophyllaChunetKuang)的生存现状,对位于湖南八面山脚盆辽的银杉+南方铁杉也Tsugachinensisvar.tchekiangensis(Flous)ChengetL.K.Fu页+甜槠也Castanopsiseyrei(Champ.)Tutch.页-猴头杜鹃(Rhodod... 为了解中国特有孑遗植物银杉(CathayaargyrophyllaChunetKuang)的生存现状,对位于湖南八面山脚盆辽的银杉+南方铁杉也Tsugachinensisvar.tchekiangensis(Flous)ChengetL.K.Fu页+甜槠也Castanopsiseyrei(Champ.)Tutch.页-猴头杜鹃(RhododendronsimiarumHance)群落进行调查,分析其群落特征及种群年龄结构,比较分布在不同区域的6个银杉群落中种子植物属的分布区类型及其相似性系数;在此基础上,讨论了银杉群落的残遗性特征。结果显示:脚盆辽银杉群落共有维管植物66种,包括蕨类植物4种和种子植物62种(裸子植物4种、被子植物58种);该群落乔木层的主要优势种为甜槠、猴头杜鹃、银杉和南方铁杉,重要值分别为13.12%、9.28%、8.86%和7.49%;该群落的Simpson和Shannon-Wiener多样性指数分别为0.94和3.20,Pielou均匀度指数Jsw和Jsi分别为0.81和0.92,说明该群落物种多样性偏低但物种分布均匀,与中亚热带山地的暖性针阔叶混交林特征一致。从生活型谱看,该群落中各频度百分比由高至低依次为A级、B级、C级、D级、E级,与Raunkiaer标准频度图谱基本一致,表明该群落整体上处于较为稳定的亚顶极状态。从银杉种群年龄结构看,种群中幼龄个体占一定比例,但80~180a的中龄个体比例偏低;从该群落优势种的径级结构看,甜槠、猴头杜鹃和鹿角杜鹃(RhododendronlatoucheaeFranch.)种群为增长型种群,而银杉、南方铁杉和福建柏也Fokieniahodginsii(Dunn)HenryetThomas页种群为衰退型种群。从脚盆辽银杉群落种子植物属的分布区类型看,温带分布型属占51.06%,略高于热带分布型属(占48.94%),说明该区域属于热带亚热带过渡区;除纬度外,海拔也能够在一定程度上影响其分布区类型组成。在处于粤北、粤桂山地和贵州高原3个植物区系亚地区的6个银杉群落中,种子植物属分布区类型的相似性系数为0.35~0.67,群落建群种所在属如铁杉属也Tsuga(Endlicher)Carri侉re页、润楠属(MachilusNees)、水青冈属(FagusLinn.)和福建柏属(FokieniaHenryetThomas)等在各群落间有相似性和共通性,且多为古老成分和孑遗成分,表明现存的银杉群落具有相近的变迁历史,分布地域具有明显的亚热带山地避难所特征,体现出其演替过程的残遗性和保守性。研究结果表明:在银杉群落中适度疏通林窗,降低林下郁闭度,有利于银杉幼树的生长,使银杉种群得到可持续更新和演替。 展开更多
关键词 湖南八面山脚盆辽 银杉 群落特征 分布区类型 种群年龄结构 残遗性
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神农架究竟存在野人吗
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《语文世界(上旬刊)》 1996年第3期48-48,共1页
神农架究竟存在野人吗野人”的传说,由来已久。所持的态度,有肯定有否定,众说纷纭,还未有定论。在中国,关于“野人”最引人注意的地方是鄂西北神农架。神农架到处流传的“野人”的传闻,并非都是虚妄之谈,当地民众以及考察队人员... 神农架究竟存在野人吗野人”的传说,由来已久。所持的态度,有肯定有否定,众说纷纭,还未有定论。在中国,关于“野人”最引人注意的地方是鄂西北神农架。神农架到处流传的“野人”的传闻,并非都是虚妄之谈,当地民众以及考察队人员曾多次亲眼目击“野人”的“庐山真面... 展开更多
关键词 神农架 “野人” 植物区系 地质条件 喜马拉雅造山运动 残遗性 动物区系 南亚热带气候 特殊 小熊猫
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Physical activity and exercise training in young people with cystic fibrosis:Current recommendations and evidence
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作者 Craig A. Williams Daniel Stevens 《Journal of Sport and Health Science》 SCIE 2013年第1期39-46,共8页
Despite the acceptance of physical activity (PA) being integral to a young person's health, children with disability often exhibit low levels of PA. In young people with cystic fibrosis (CF) the importance of exe... Despite the acceptance of physical activity (PA) being integral to a young person's health, children with disability often exhibit low levels of PA. In young people with cystic fibrosis (CF) the importance of exercise and daily PA is acknowledged by clinicians and their support teams, however, there is a lack of knowledge related to its prescription. CF is a recessive genetic disorder affecting the lung, pancreas and sweat glands. CF is the most common life shortening genetic disease in the Caucasian population for which there is no cure. In the UK, CF affects over 9000 people, with 4000 under 16 years of age. Only about half of the CF population can expect to live beyond 40 years of age. Besides drug therapies, rehabilitative exercise programmes form an important component of treatment and long term exercise programmes are considered positive treatment strategies, but all lack any detailed prescriptive information. Several reviews and editorials have highlighted the lack of evidence based research in PA and exercise training in young people with CF; but advocate a greater need for understanding the role of exercise in therapeutic interventions. The purpose of this review is to update the reader on the current recommendations and evidence in PA and exercise training for young people with CE These developments have extended our understanding of PA and exercise training in children and adolescents with CF, and its implementation in the management of this chronic disease. 展开更多
关键词 Cystic fibrosis Exercise training PAEDIATRICS Physical activity Young people
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