摘要
飞播造林是我国偏远山区重要的植被恢复模式之一,探讨林地质量和调控措施对飞播林的可持续经营具有重要的实际意义。该文于2000年在北京市延庆县王家堡飞播基地,对飞播造林密度为8 000株/hm^2的9年生油松林设置30%（弱度）、48.75%（中度）、53.75%（强度）、77.13%（超强度）4个间伐强度及0%（对照）共5个处理。5年后,通过比较不同季节0-20 cm土壤的酶活性及其与土壤理化性质的关系,探讨土壤酶作为筛选间伐强度的可行性。结果表明：①土壤氧化还原酶活性峰值出现在6月份,而脲酶、碱性磷酸酶活性峰值出现在10月份,转化酶出现在4月份;②5种土壤酶活性对间伐强度响应不同,弱度间伐的土壤过氧化氢酶、脲酶和转化酶活性最大,中度间伐的土壤多酚氧化酶和碱性磷酸酶活性最大;③土壤酶与土壤有机质和速效钾显著相关,土壤水分可能是限制土壤酶活性的关键因子;④土壤酶较土壤理化性质对间伐响应敏感,土壤碱性磷酸酶和过氧化氢酶可以作为飞播油松林土壤质量评价的指标。因此,及时对郁闭林分进行合适强度的间伐,促进林下植被发育,提高土壤酶活性,从而实现油松人工林可持续发展;9年生初植密度8 000株/hm^2的油松幼林选择48.75%左右的间伐强度最优。
Aerial seeding is one of the most important vegetation restoration patterns in remote hilly areas, and the study concerning soil quality and its management is valuable to the practice. In 2000, the effects of thinning intensity with five different treatments of 0% （CK）, 30% （slight thinning）, 48.75 % （middle thinning）, 53.75 % （intensive thinning） and 77.13 % （super intensive thinning） on the soil enzyme were carried out in the 9-year-old aerial seeding Pinus tabulaeformis stands with initial density of 8 000 trees/hm^2, in Wangjiapu Aerail Seeding Center, Yanqing County of Beijing. Five years later, the activities of the five kinds of soil enzymes such as soil urease, alkaline phosphatase, inertase, catalase and polyphenol oxidase in the soil layer of 0-20 cm were compared in four seasons. Moreover, relations among soil enzymes and soil physiochemical properties were analyzed to prove the availability of using soil enzymes to evaluate the thinning intensities. The results showed that the maximum enzyme activities of catalase and polyphenol oxidase occurred in June. While those of soil urease and alkaline phosphatase occurred in October, its of soil invetase was in April. Also, the five soil enzymes were affected differently by thinning intensities. Soil catalase, urease and invertase were the highest response to slight thinning, followed by the middle thinning, opposite to polyphenol oxidase and alkaline phosphatase to middle thinning. There are significantly positive relations between soil enzymes and the organic C and available K. It should be noted that soil water was a limiting factor to soil enzymes possible. Compared with soil physicochemical characteristics, soil enzymes were more sensitive to thinning intensity. Among them, soil alkaline phosphatase and catalase could be regarded as indicators to assess soil quality. It is concluded that reasonable thinning intensity is benefitial to the development of the undergrowth and soil enzymes. Generally, when the stand with initial density of 8 000 trees/hm^2 grows up to nine years old, the reasonable thinning intensity should be about 48.75 %.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2008年第2期82-88,共7页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(30471380)
北京市教委项目(JD100220648)
关键词
油松
飞播林
间伐强度
土壤酶
土壤养分
Pinus tabulaeformis
aerial seeding stands
thinning intensity
soil enzyme
soil nutrient
作者简介
李国雷，博士。主要研究方向：人工林培育及植被恢复与重建。电话：010-62347725 Email：g11i226@163．com地址：100083北京林业大学林学院47信箱。
责任作者：刘勇，教授，博士生导师。主要研究方向：森林培育学。电话：010-62338994 Email：lyong@bjfu．edu．cn地址：同上。
