长白山紫椴种子雨的时空分布格局  

Spatiotemporal Dynamics of Seed Rain of Tilia amurensis in Forest Stands in Changbai Mountain

作　　者：陈香茗[1] 赵秀海[1] 夏富才[2] 王蕾[1] 陈贝贝[1] 

机构地区：[1]北京林业大学,北京100083 [2]北华大学

出　　处：《东北林业大学学报》2011年第1期7-10,共4页Journal of Northeast Forestry University

基　　金：国家自然科学基金(30940012);财政部林业公益性行业科研专项项目(200904022);国家“十一五”科技支撑项目(2006BAD03A0804、2008BADB0B0503)资助

摘　　要：以长白山不同演替阶段的森林群落（次生针阔混交林、次生杨桦林和原始阔叶红松林）内设置的永久样地为基础，布设种子收集器，定期收集并鉴定其中的种子，研究了紫椴（Tilia amurensis）种子雨的时空格局及其扩散机制。结果表明：不同森林群落中紫椴种子雨均始于7月末，持续近3个月，种子散布的时间序列为双峰曲线。第一峰值出现在9月中旬，第二峰值出现在8月中旬。7月末至9月初种子粒径增加明显．9月中旬之后，种子基本发育完全。原始红松林内紫椴种子雨的平均密度最大，为（239．8±185．4）粒·m^-2；次生针阔混交林次之，平均密度为（222．7±135．2）粒·m^-2，这两个林分的种子雨分布的聚集性较强。次生杨桦林中紫椴种子雨密度最小，仅有（94．1±112．6）粒·m^-2，分布较随机。紫椴是针阔混交林和原始红松林中的林冠层优势树种．结实稳定，而在次生杨桦林中，紫椴以幼树为主，结实率较低。在次生针阔混交林内，紫椴种子雨与成树的胸径显著正相关，而在原始阔叶红松林和次生杨桦林内的相关性不显著。紫极种子雨主要集中在母树的树冠范围内，空间格局自相关尺度为13．2～17．9m，但随与紫椴母树距离的增加，种子雨密度逐渐减小，趋于随机性分布格局。紫椴种子雨扩散的有效性表明：在靠近母树区域，种子雨密度远远大于幼苗密度。Seed traps were installed to collect fallen seeds in three different types of forests in Changbai Mountain to explore the abundance and spatio-temporal dynamics of seed rain of Tilia amurensis. The three forest types were Mixed forests with Coniferous and Broad-leaved species （MCB）, Secondary Poplar-Birch forest （SPB） and Original broad-leaved Korean Pine forest （OKP）. Results showed that the seed rains started from late July and maintained nearly three months in all the studied stands. Two peaks occurred during the process of seed dispersals. The first peak appeared in mid-September and the second one in mid-August. Seed diameter increased obviously from late July to early September. And almost all the seeds finished their development after mid-September. The patterns of T. amurensis seed rain were various between different stands. In the MCB forest, the average seed intensity was 222.7±135.2 seeds per square meter, and the seed rain spatial pattern mainly showed an aggregated distribution. In the SPB forests, the seed intensity was only 94.1 ±112.6 seeds per square meter, and the seed rain pattern mainly appeared to be a random distribution. The OKP forest had the highest seed density of 239.8±185.4 seeds per square meter, and the seed rain spatial pattern mainly showed an aggregated distribution. The MCB and OKP forests showed a high proportion of mature trees. In these forests, T. amurerensis became a dominant species, and its seed-setting rate appeared to be stable. In the younger secondary poplar-birch forests, the species did not achieve dominance and the seeding rate was low. Seed density was positively associated with the diameter of T. amurensis at breast height at the 0.01 level of significance in the MCB forest. However, the correlations between seed density and diameter at breast height were not significant in the SPB and OKP forests. Seed fall decreased exponentially with increasing distance from the position of sample T. amurensis. A semi-variogram analysis revealed an approximately

关 键 词：紫椴 种子雨 幼苗 时空格局 长白山 

分 类 号：Q948.122.6[生物学—植物学]