检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
机构地区:[1]华南农业大学林学院,广州510642 [2]广东省林业局,广州510173
出 处:《应用生态学报》2003年第6期875-878,共4页Chinese Journal of Applied Ecology
基 金:国家教委留学回国人员启动基金资助项目 (1999 3 63 )
摘 要:从叶完全展开到生长季结束 ,对常绿阔叶树种日本米槠、具柄冬青、铁冬青、红楠和海桐及落叶阔叶树种木包栎、栓皮栎、日本朴、银杏和日本树五加的叶N和P含量进行了测定 .结果表明 ,在整个生长季中 ,常绿阔叶树种中的日本米槠和铁冬青的新叶和老叶的N和P含量呈现初期高、中期较低、后期上升的趋势 ;具柄冬青和海桐新叶的N和P含量的变化趋势与日本米槠和铁冬青相似 ,而其老叶的N和P含量随季节推移而逐渐下降 ;红楠新叶和老叶的N含量呈现上升的趋势 ,其新叶和老叶的P含量则呈下降趋势 ;落叶阔叶树种的叶N和P含量随着时间的推移不断减少 .各树种的N转移率为 4 3%~ 75 % ,P为6 2 %~ 84 % .常绿阔叶树种的N平均转移率与落叶阔叶树种相似 ,而其P平均转移率大于落叶阔叶树种 .所有树种的N平均转移率小于P平均转移率 .The leaves of evergreen broadleaved Quercus cuspidata,Ilex pedunculosa,Ilex rotunda,Machilus thunbergii,Pittosporum tobira and deciduous broadleaved Quercus serrata,Quercus variabilis,Celtis sinensis,Ginkgo biloba, and Evodiopanax innovans were collected from the time of full leaf expansion to the end of growing season to describe the seasonal contents of N and P patterns in leaves of these species. The N and P contents in new and old leaves of evergreen Quercus cuspidata and Ilex rotunda had high levels in initial stage,low levels in medium stage,and increased in later stage. The seasonal changes of the N and P contents in new leaves of evergreen Ilex pedunculosa and Pittosporum tobira were similar to those of Quercus cuspidata and Ilex rotunda ,whereas in old leaves of the two species,they tended to decline with time.The N content in new and old leaves of Machilus thunbergii tended to increase,whereas their P content tended to decrease. The N and P contents in leaves of deciduous species decreased during the growing season.The N translocation efficiency for all species ranged from 43~75%,whereas their P translocation efficiency ranged from 62~84%.The N translocation efficiency in evergreen broadleaved species was similar to that in deciduous broadleaved species,whereas the P translocation efficiency was higher than the latter. The mean N retranslocation efficiency for all species was higher than mean P retranslocation efficiency.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.229