施氮肥对水曲柳人工林细根生产和周转的影响  

Effects of nitrogen fertilization on fine root biomass production and turnover of Fraxinus mandshurica plantation

作　　者：梅莉[1] 王政权[2] 张秀娟[3] 于立忠[4] 杜英[1] 

机构地区：[1]华中农业大学园艺林学学院,武汉430070 [2]东北林业大学林学院,哈尔滨150040 [3]长江大学园艺学院,湖北荆州434023 [4]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2008年第10期1663-1668,共6页Chinese Journal of Ecology

基　　金：国家自然科学基金重点项目(30130160);华中农业大学科技创新基金(2007XCX023);华中农业大学引进人才科研启动资助项目(2006XRC053)

摘　　要：细根周转与土壤养分密切相关,但由于根系研究方法的差异以及研究对象的不同,土壤养分对细根周转影响的研究存在不一致的结论。本文以水曲柳(Fraxinus mandshurica)人工林为对象,应用3种方法研究施氮肥对细根生产和周转的影响。结果表明:施肥降低了活细根现存生物量,但施氮肥样地细根年生产量平均值(93.105g·m-2·a-1)与对照样地(93.505g·m-2·a-1)没有差异,不同方法得出施氮肥样地细根平均周转率(0.917次·a-1)大于对照样地(0.710次·a-1);不同土层内细根的生产量显著不同,表层生产量最大,土层越深细根生产量越低,但细根周转率一般随土壤加深而加快;不同的研究方法得出细根的年生产量和周转率差异较大,分室模型法最高,其次是内生长土芯法,极差法和积分法最低。Fine root turnover has close relations with soil nutrient availability. However, owing to the differences in test objects and in the methodology for assessing fine root behaviors, some contradictory results could be obtained. In this paper, sequential soil core, in-growth core, and decomposition method were employed to study the effects of nitrogen fertilization on the fine root （ diameter 〈 1 mm） biomass production and turnover of Manchurian ash （ Fraxinus mandshurica） plantation, and four calculation methods were used to determine the fine root＇ s standing biomass and turnover rate. The results showed that under nitrogen fertilization, the fine root＇ s standing biomass decreased, but its mean annual production （93. 105 g·m^-2 ·a^-1 ） in 0-30 cm soil layer in 2003 and 2004 was similar to the control （93. 505 g ·m^-2·a^-1 ）. The fine root＇ s mean turnover rate was higher under nitrogen fertilization （0. 917 times·a^-1 ） than under the control （0. 710 times·a^-1）. Fine root production decreased significantly with soil depth, but its turnover rate was generally in adverse. Greater differences were observed in estimating the fine root production and turnover rate by the four calculation methods, with the highest values by sequential-coring approach with compartmental-flow calculation, followed by in-growth-core, minimum-maximum and adding increments method calculations.

关 键 词：水曲柳 细根 生产量 周转率 

分 类 号：S792.41[农业科学—林木遗传育种]