重庆铁山坪马尾松林凋落物输入及分解动态与持水特性
王轶浩1, 周建岗2, 王彦辉3

(1.重庆师范大学 地理与旅游学院 重庆市三峡库区地表生态过程野外科学观测研究站, 重庆 401331; 2.沁县漳源林场, 山西 沁县 046400; 3.中国林业科学研究院 森林生态环境与保护研究所 国家林业和草原局森林生态环境重点实验室, 北京 100091)

凋落物; 组分; 分解; 持水能力; 马尾松林

Production and Decomposition and Water-holding Capacity of Litter in Pinus massoniana Forests in the Tieshanping of Chongqing
WANG Yihao1, ZHOU Jiangang2, WANG Yanhui3

(1.Chongqing Field Science Observation and Research Station for Surface Ecological Process of Three Gorges Reservoir Area, College of Geography and Tourism, Chongqing Normal University, Chongqing 401331, China; 2.Zhangyuan Forest Farm of Qinxian County, Qinxian, Shanxi 046400, China; 3.Key Laboratory of Forest Ecology and Environment, National Forestry and Grassland Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China)

litter; component; decomposition; water holding capacity; Pinus massoniana forest

备注

为揭示三峡库区马尾松林凋落物现存量及其生态水文效应,采用定位监测与室内测定相结合的方法,对马尾松林凋落物输入、分解及其持水能力进行了研究。结果表明:(1)马尾松林月总凋落物量变化为11.54～90.31 g/m2,与其组分(除阔叶外)的年内变化均呈“双峰”模式; 年凋落物组分排序为枯死针叶>有机碎屑>树枝>阔叶>树皮及球果>青黄针叶。(2)凋落物现存量为1 204 g/m2,其中未分解层、半分解层和已分解层分别占29.98%,31.56%,38.46%。(3)凋落物年失质量率为35.62%,月失质量率变化为1.04%～6.75%,干质量残留率与分解时间呈显著负相关关系(p<0.01)。(4)未分解层、半分解层和未分解+半分解层凋落物的有效拦蓄水深分别为0.50,0.59,1.12 mm,其持水率均随浸水时间呈倒“J”型变化(p<0.01),吸水速率则均随浸水时间呈“J”型变化(p<0.01)。可见,马尾松林凋落物各组分输入量、各层次储量及其持水能力均有较大差异,研究结果可为三峡库区马尾松林水源涵养功能准确评价提供科学依据。
To reveal litter accumulation amount of Pinus massoniana forests and its eco-hydrological effects in the Three Gorges Reservoir area, production, decomposition and water-holding capacity of litter in Pinus massoniana forests were studied by using the method of fixed observation and measurement of laboratory. The results showed that:(1)the monthly litter amount of Pinus massoniana forests ranged from 11.54 g/m2 to 90.31 g/m2; except broad leaves, the monthly variation of total litter and its components presented a two-peak pattern; the yearly amount of litter components decreased in the order: dead needles>debris>twigs>broad leaves>bark and cones>green needles;(2)the litter accumulation amount of Pinus massoniana forests was 1 204 g/m2, and the undecomposed litter layer, the half-decomposed litter layer and the undecomposed litter mixed with half decomposed litter layer accounted for 29.98%, 31.56% and 38.46% of litter accumulation amount, respectively;(3)the annual mass loss ratio of litter of Pinus massoniana forests was 35.62%, and the monthly mass loss ratio ranged from 1.04% to 6.75%; the mass remaining percentage for the decomposing litter of Pinus massoniana forests was significantly negative correlated with decomposition time(p<0.01);(4)the effective interception water depths of the undecomposed litter layer, the half-decomposed litter layer and the undecomposed litter mixed with half decomposed litter layer were 0.50 mm, 0.59 mm and 1.12 mm, respectively; variations of water holding rates of different types of litter all presented an inverted J-shaped feature over the immersed time, and variations of water absorption rates of different types of litter all presented a J-shaped feature over the immersed time. In summary, productions of litter components, accumulation amounts of litter layers and their water-holding capacities of Pinus massoniana forests were all different. These results can provide the scientific basis for accurately evaluating water conservation service function of Pinus massoniana forest in the Three Gorges Reservoir area.