重庆酸雨区缙云山典型林分冠层酸雨淋洗特征  

Canopy Leaching Characteristics of Typical Forests during Acid Rain at Jinyun Mountains,Chongqing

作　　者：唐晓芬[1] 王云琦[1] 王玉杰[1] 张会兰[1] 郭平[1] 胡波[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《林业科学研究》2013年第5期548-553,共6页Forest Research

基　　金：国家自然科学基金项目(31100515);高等学校博士学科点专项科研基金(20110014120001)资助

摘　　要：选取重庆缙云山的针阔混交林、常绿阔叶林、毛竹林、灌木林4种典型林分,观测酸性降水过程中林外雨、穿透雨及干流等林内水分转换分量中的主要离子含量变化,分析林分冠层对雨水化学组成的影响,结果表明:(1)降雨中的离子当量浓度大小依次是SO42->Ca2+>NH4+>Mg2+>K+>Na+>NO3-;(2)降雨经过林冠层后pH值降低,干流的酸化程度增加最大;(3)降雨经林冠层后离子浓度明显增加(除灌木林),穿透雨中通量增加最大的阴离子和阳离子分别为SO42-(2.19×1036.47×103eq·hm-2)和Ca2+(1.41×1033.39×103eq·hm-2),离子来源主要为大气沉降和植物分泌物或淋出;(4)同一离子在不同林分的干流和穿透雨中的通量变化不同,反映出不同林分冠层的离子交换性差异。在针阔混交林中,林下降雨净淋溶量大小顺序为SO42->Ca2+>NO3->K+>NH4+>Mg2+>Na+;常绿阔叶林为SO42->Ca2+>K+>NO3->NH4+>Mg2+>Na+;毛竹林为Ca2+>SO42->K+>NO3->NH4+>Na+>Mg2+;灌木林为Ca2+>NO3->K+>Na+>Mg2+>NH4+>SO42-。Based on continuous monitoring of precipitation and throughfall in the i.e. mixed coniferous forest, evergreen broad-leaved forest, bamboo forest and canopy layer of four typical forests, shrubbery, at Jinyun mountains in Chongqing Municipality, the change of major ion content in precipitation, throughfall and stemflow was detected, and the characteristics of redistribution and leaching effects of the canopy layer on acid rain were analyzed. The re- sults are as follows. （ 1 ） The equivalent concentration of major ions were in the ordered of S04z- 〉 Ca2 ~ 〉 NH4 ~〉 Mg2~ 〉 K ＋ 〉 Na ~ 〉 NO3 - （2） The pH value decreased after rainfall passed through the forest canopy, and the stemflow was more acidic compared to throughfall （3） The maximum concentration of anion and cation are S042- （2.19 ~ 103 ~ 6.47 ~ 103 eq ~ hm-2） and Ca2~ （ 1.41 ~ 103 ~ 3.39 ~ 103 eq ~ hm-2 ） in throughfall. The atmospheric precipitation and plant secretion were the primary ion resources within the study area. （4） The concen- tration variation of one certain ion varied in different stands, demonstrating the divergence property of canopy ex- change within different tree species stands. The crown leaching array of major ions from high to low in mixed conif- erous forest is SO4 2-（2.19×10^3～6.47×10^3eq·hm-2） and Ca2＋（1.41×10^3～3.39×10^3eq·hm-2） , that in evergreen broad-leaved forest is 〉Na＋〉Mg2＋,and in shrubbery is Ca2＋〉NO3-〉K＋〉Na＋〉Mg2＋〉NH4＋〉SO4 2-.

关 键 词：酸雨淋溶 穿透雨 树干茎流 养分含量 缙云山 

分 类 号：S715[农业科学—林学]