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濒危植物长柄双花木自然种群生殖构件的时空动态

肖宜安1,2 何平1** 胡文海2 李晓红2   

  1. 1西南师范大学生命科学学院,重庆 400715;2井冈山师范学院生命科学系,
    吉安 343009
  • 收稿日期:2004-03-10 修回日期:2004-07-05 出版日期:2005-07-18

Temporal and spatial dynamics of reproductive modules of endangered plant Disanthus cercidifolius var.longipes natural populations

XIAO Yian1,2,HE Ping1,HU Wenhai2,LI Xiaohong2   

  1. 1School of Life Science,Southwest China Normal Unive
    rsity,Chongqing 400715,China;2Department of Life Science,Jinggangshan Norm

    al College,Ji'an 343009,China

  • Received:2004-03-10 Revised:2004-07-05 Online:2005-07-18

摘要: 根据野外观测数据,研究了濒危植物长柄双花木(Disanthus cercidifolius var.longipes)在不同生境条件下自然种群开花物候变异以及生殖构件的时空动态.结果表 明,不同群落类型中长柄双花木开花物候存在一定差异,在纯林中个体的平均花期最长,达75 d,而个体间开花同步性最低,仅为0.717;竹林中的个体花期最短,只有47d,而同步指数最高,达0.968;生殖枝数量及花序数均随个体年龄增长而增加,在年龄为30~35年时达最高,此后又呈下降趋势;在海拔为810m左右处,个体生殖枝数及着生的花序数均达最大值,且冠层间差异明显;纯林中个体着生的生殖枝数及每生殖枝上着生的花序数均最高,分别为411.39和7.857;竹林中个体每生殖枝着生的花序数显著低于其它群落.年龄小的个体,各时期生殖构件败育率均高于年龄大的个体;另外,生殖构件的败育与海拔高度间无相关性,而与构件发育时间、分布的树冠层次以及所处的群落类型相关.影响生殖构件败育的主要因子是光照条件.

关键词: 氮总矿化, 总硝化, 草地, 15N

Abstract: Based on field observation data,this paper studied the flowering phenology and the temporal and spatial dynamics of the reproductive modules of endangered plant Disanthus cercidifolius var.longipes natural populations.The results showed that there were certain differences of the flowering phenology among the populations in different communities,e.g.,in pure forest,the average flowering duration of individuals was the longest (75 d),while the flowering synchrony was the lowest (0.717 d),but in bamboo forest,the flowering duration of individuals was the shortest (47 d),while its flowering synchrony was the highest.The numbers of reproductive branches and inflorescences were increased with increasing individual age,and reached the highest at the age of 30~35yr.At the elevation of 810 m,the numbers of individual reproductive branches and inflorescences reached the peak,and there were significant differences among the crown levels.The reproductive branch number of individuals and the inflorescences per reproductive branch were the highest in pure forest,being 411.39 and 7.857,respectively,while the inflorescences per reproductive branch in bamboo forest were notably lower than those in other communities.The abortive ratio of reproductive modules of young individuals was higher than that of the older ones in the flower?bud,flowering,and fruit phases.The abortion of reproductive modules had no correlation with their distributed elevation,but some correlations existed with their development time,distributed crown levels and communities.The major factor affecting the abortive ratio of individual reproduction modules was probably the illumination condition in the distributed communities.

Key words: Gross mineralization, Gross nitrification, Grasslands, 15N isotope