重庆酸雨区受害马尾松林土壤水分与针叶凋落的关系  

Relationships between soil moisture and needle-fall in Masson pine forests in acid rain region of Chongqing,Southwest China

作　　者：王轶浩[1,2] 王彦辉[1] 李振华[1] 于澎涛[1] 熊伟[1] 郝佳[1] 段健 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所国家林业局森林生态环境重点实验室,北京100091 [2]重庆市林业科学研究院,重庆400036 [3]重庆市江北区铁山坪林场,重庆400026

出　　处：《应用生态学报》2012年第10期2632-2640,共9页Chinese Journal of Applied Ecology

基　　金：中-挪合作项目(193725/S30);林业公益性行业科研专项(200904005;200904056;201104005-02)资助

摘　　要：2009年3月—2011年11月,研究了重庆铁山坪酸雨区马尾松林土壤水分的时空变化及其对针叶凋落的影响,并确定了其相应的土壤水分阈值.结果表明:无论是丰水年、平水年还是少水年,马尾松林土壤水分年内变化均明显分为丰富期(5月前)、下降期(6—7月)、伏旱期(8—9月)和恢复期(10—11月);随土层深度增加,土壤含水量先减少后增加,各土层间土壤含水量的差异随年降水量的下降而减小;生长季中马尾松林的月针叶凋落量与0～60cm(尤其是20～50cm)的蓄水量显著相关;土壤田间持水量(或毛管孔隙度)和82%的田间持水量(或80%的毛管孔隙度)是影响针叶凋落的重要土壤水分阈值.酸雨区马尾松林极易遭受缺水胁迫,特别是在伏旱期.其与酸害共同构成了酸雨区森林健康的多重胁迫.From March 2009 to November 2011,an investigation was conducted on the spatiotemporal variation of soil moisture and its effects on the needle-fall in Masson pine （Pinus massoniana） forests in acid rain region of Chongqing,Southeast China,with the corresponding soil moisture thresholds determined.No matter the annual precipitation was abundant,normal or less than average,the seasonal variation of soil moisture in the forests could be obviously divided into four periods,i.e.,sufficient （before May）,descending （from June to July）,drought （from August to September）,and recovering （from October to November）.With increasing soil depth,the soil moisture content increased after an initial decrease,but the difference of the soil moisture content among different soil layers decreased with decreasing annual precipitation.The amount of monthly needle-fall in the forests in growth season was significantly correlated with the water storage in root zone （0-60 cm soil layer）,especially in the main root zone （20-50 cm soil layer）.Soil field capacity （or capillary porosity） and 82% of field capacity （or 80% of capillary porosity） were the main soil moisture thresholds affecting the litter-fall.It was suggested that in acid rain region,Masson pine forest was easily to suffer from water deficit stress,especially in dry-summer period.The water deficit stress,together with already existed acid rain stress,would further threaten the health of the Masson forest.

关 键 词：酸雨区 森林健康 缺水胁迫 马尾松林 

分 类 号：X517[环境科学与工程—环境工程] S761.6[农业科学—森林保护学]