【作者】 张艳华；

【导师】 聂绍荃； Ken C.Hodgkinson；

【作者基本信息】 东北林业大学 ， 植物学， 2003， 博士

【摘要】 通过对澳大利亚东南部台地桉树疏林地退化生态系统退化的原因、过程、阶段和恢复桉树种群的方法进行全面系统的研究和讨论，总结出人为干扰因素(开垦和放牧)是导致桉树疏林地植被种类结构及功能下降的直接原因，并通过与自然干扰因素(气候因子、地形因子和土壤因子)的交互作用使桉树种群在其天然分布区恢复和更新受到阻碍。系统分析了在开垦和放牧等人为因素干扰下的6种植被状态类型和桉树幼苗更新的相关关系，结果表明开垦条件下，在乡土多年生草本占优势和轻度放牧的植被状态类型中，桉树天然更新的效果最佳。在年降雨量700～800mm的地区更新幼苗的数量最多，温度和土壤类型对幼苗的更新没有显著的影响。在低平地桉树更新好于坡地和山脊，在桉树天然更新中，乡土多年生草本植物在疏林地中的比例对幼苗更新数量影响较大。桉树更易于在低盐化的土壤上更新，酸化对桉树整体的更新影响不显著。单蒴盖亚属和双蒴盖亚属的桉树更新效果相比，双蒴盖亚属对环境的适应能力较强，可以在较大范围内进行更新，双蒴盖亚属的E．blakelyi，melliodora和E．bridgesiana可以作为在澳大利亚东南部台地恢复更新的先锋树种，应扩大其更新的面积和规模，吸引乡土多年生草本植物在疏林地中更新，并为其他种类的桉树更新创造适宜的条件。对那些在局部地区占优势的种类要进行保护，减少人为干扰，使退化的桉树疏林地生态系统尽早恢复到进展演替的轨道上来。更多还原

【Abstract】 Generally and systematically studied and discussed on the eucalypt woodland ecosystem about degraded causes, courses, phases and restoration methods in Southeastern Tablelands of Australia. Decline of species, structure and function of eucalypt woodland was resulted mainly by man-made disturbance factors, which included clearing and grazing activities. Those factors interacted with natural disturbance factors and impacted on the eucalypt recruitment in their natural distribution regions.Eucalypt recruitment effects were discussed under six vegetation states, which divided by the degree of clearing and grazing and some other factors as well. Seedling recruitment was much better when the vegetation was uncleared, perennial native grass were dominated and little grazing occurred in the same time. There was very nice regeneration when the rainfall range was 700 mm to 800 mm. Highest and lowest temperatures and soil types were not crucial factors on the recruitment. The eucalypt seedling numbers per ha were much higher on bottom rather than crest and slope. Eucalypt preferred to have seedlings in low salinity areas. The percent of perennial native grass in the understory played an important role in eucalypt recruitment.The ability of regeneration was significantly difference between eucalypt species. Comparison of Monocalyptus and Symphyomyrtus species showed that Symphyomyrtus species could be more tolerant on the disturbed environment than Monocalyptus species and their seedlings distributed in wider range areas.E. blakelyi, E. melliodora and E. bridgesiana etc. could be utilized to restore the eucalypt woodlands in Southeastern Tablelands in Australia as pioneers to enlarge the remnant woodland areas. Perennial native grass could be attracted in the modified woodland and provided suitable environment for tree recruitment. Local dominant species should be protected. Declining the man-made disturbance factors and facilitating degrades ecosystems to back to the progressive succession route should be done in the future.更多还原