Studies on life patterns of evergreen broad-leaved trees growing in cool and nutrient-limited sites

凉爽和营养有限地区常绿阔叶树生活模式的研究

基本信息

批准号：
12640609
负责人：
YAMAMURA Yasuo
金额：
$ 1.98万
依托单位：
IBARAKI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

(1) Ecophysiology and matter economy were investigated for evergreen plants in montane and subalpine sites in Mt Fuji, a volcanic mountain in central Japan, to clarify the mechanism of dominance of evergreen plants under nutrient-limited conditions.(2) On a lava bed in the montane site, forest canopy is dominated by an evergreen conifer (Pinus densiflora) and under-canopy layer is dominated by evergreen broadleaf trees (Irex pedunculosa, Pieris japonica). Evergreen broadleaf trees were different from deciduous ones in several ecophysiological features; (1) Annual turnover rate of nitrogen of evergreens was lower, (2) Evergreen leaves served as storage organs and nitrogen was retranslocated from the leaves to growing shoots in spring, (3) Maximum photosynthetic rate of evergreens was lower, but there were no difference in daily matter production because midday depletion of photosynthetic activity did not occur in evergreens, (4) Annual productivity of evergreens was higher because of photosynthetic activity before and after growing season for deciduous trees. Consequently nitrogen use efficiency (NUE) of evergreens was higher.(3) The evergreen pine tree on the lava bed had much storage nitrogen in leaves, which was retranslocated to shoots growing under more favorable light condition, and had higher NUE than that on a deep soil. High NUE was also observed in an evergreen herb in the subalpine site. Evergreen leaves served to photosynthesize under a favorable light condition in early spring.(4) These results indicated that evergreenness caused a conservative nutrient economy and high NUE in cool and nutrient-limited sites.

(1) 对日本中部火山富士山的山地和亚高山地区的常绿植物进行了生态生理学和物质经济研究，以阐明营养有限条件下常绿植物的优势机制。(2) 在熔岩床上在山地地区，森林冠层以常绿针叶树（Pinus densiflora）为主，冠层下以常绿阔叶树（Irex）为主pedunculosa、Pieris japonica）。常绿阔叶树在几个生态生理特征上与落叶树不同； (1)常绿植物氮素年周转率较低，(2)常绿植物叶片作为贮藏器官，春季氮素从叶片转移到生长中的地上部，(3)常绿植物最大光合速率较低，但没有(4) 常绿植物的年生产力较高，因为落叶乔木在生长季节前后都有光合活动，因此常绿植物的年生产力较高。 (3)熔岩床上的常绿松树叶片中储存有较多的氮素，这些氮素会重新转移到在更有利的光照条件下生长的地上部，其NUE高于熔岩床上的常绿松树。深厚的土壤。在亚高山地区的常绿草本植物中也观察到较高的 NUE。常绿叶子在早春有利的光照条件下进行光合作用。(4)这些结果表明，常绿导致了凉爽和养分有限的地区保守的养分经济和高NUE。