桉树人工林土壤环境对植物种子发芽和生长的影响  

Effect of Soil Environment of Eucalyptus Plantations on Seed Germination and Seedling Growth

作　　者：杨小波[1] 李东海[1] 李跃烈[1] 

机构地区：[1]海南大学生命科学与农学院,海口570228

出　　处：《林业科学》2006年第12期148-153,共6页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(30160070)资助。

摘　　要：桉树（Eucalyptus）已成为我国华南地区很重要的速生阔叶用材树种，在海南已成为仅次于天然林、橡胶林的第三大森林生态系统。但随着大面积营造桉树人工纯林，生产上出现一些负面的影响，其社会效益和生态效益问题日益得到重视，其旺盛的生长是否会造成地下水的过量消耗，大面积的种植桉树人工林从而造成部分林地降低了地下水位、造成土壤的退化和影响林下植物种子萌发、植物的生长，林下植被的减少，土壤的退化等（蒋有绪，1992；王震洪等，1998；陈秋波，2001；林义辉，2001；项东云，2002；黄志宏，2003）。有关桉树对林下植物萌发和生长影响国内外已有一些研究，认为柠檬桉（Eucalyptus citriodora）、窿缘桉（E、exserta）、尾叶桉（E．urophylla）和刚果12号桉（E．12ABL）具有化感作用，对林下植被发育有一定的他感作用，可以抑制林下某些植物的种子萌发和幼苗生长，是造成林下植物稀少的主要原因之一（Rice，1974；Willis，1978；曹潘荣等，1996；Ewers et al，1996；曾任森等，1997；黄卓烈等，1997；潘志刚等，1997；赵绍文等，2000；黄宝灵等。2000；余雪标等，2000；陈秋波等，2002，2003；张贵荣，2003），但是李培泰（1998）认为桉树叶提取液对豌豆种子发芽没有影响。在桉树人工林林下自然环境中研究植物种子萌发和幼苗生长特点还未见相关报道，我们在野外调查中，发现相距不远的同质桉树林有一草不长的，也有林下长有较多林下植物的，桉树林对林下植物种子萌发、植物生长到底有什么样的影响，本文通过在不同的桉树林下环境中研究植物种子的萌芽和幼苗生长情况，解释其原因。In soil environment of eucalyptus plantation, the differences of stylosanthes＇s seed germination was significant when the density of Eucalyptus leaves soaking solution was 50% （patching 1 kg fresh Eucalyptus＇s leaves, soaking with 1 000 mL water 24 h）; But when the solution density were form 1% - 40%, the differences were not significant; Seed germination and seedling growth were not negative affected by different weights of Eucalyptus＇s or Eupatorium odoratum＇s leaves which patched by knife and covered with earth, while seedling growth of Stylosanthes guianensis was improved. Besides, seed germination could be improved after scarifying, and seed germination percentage after scarifying was higher 64% than no scarifying. In wild conditions, seed germination was also affected obviously by watering quantity, seed germination occurred when watering quantity was higher than 500 mL·m^-2d^1, and the highest seed germination percentage of 100% occurred when watering quantity was 2 000 mL·m^-2d^1 ; On the contrary, no seed germination occurred in controls and when watering quantity was lower than 500 mL·m^-2d^1. In room conditions, the differences of seed germination percentage with different watering quantity were significant, while differences of seed germination percentage in different eucalyptus plantation soils were not significant.

关 键 词：桉树人工林 土壤环境 种子萌发 幼苗生长 

分 类 号：S718.5[农业科学—林学]