Landscape patterns of overstory litterfall and related nutrient fluxes in a cool-temperate forest watershed in northern Hokkaido,Japan  

日本北海道北部寒温带森林流域林冠层凋落物及其养分归还量的景观格局(英文)

作　　者：徐小牛[1] 柴田英昭[2] 

机构地区：[1]安徽农业大学林学与园林学院,合肥230036 [2]日本北海道大学北方生物圈科学研究中心

出　　处：《Journal of Forestry Research》2007年第4期249-254,共6页林业研究（英文版）

基　　金：The project was supported by Japanese Society for Promotion of Sciences (15P03118).

摘　　要：Within a forested watershed at the Uryu Experimental Forest of Hokkaido University in northern Hokkaido, overstory litterfall and related nutrient fluxes were measured at different landscape zones over two years. The wetland zone covered with Picea glehnii pure stand. The riparian zone was deciduous broad-leaved stand dominated by Alnus hirsuta and Salix spp., while the mixture of deciduous broadleaf and evergreen conifer dominated by Betula platyphylla, Quercus crispula and Abies sachalinensis distributed on the upland zone. Annual litterfall averaged 1444, 5122, and 4123 kg.hm^-2·a^-1 in the wetland, riparian and upland zones, respectively. Litterfall production peaked in September-October, and foliage litter contributed the greatest amount （73.4%-87.6 %） of the annual total litterfall. Concentrations of nutrients analyzed in foliage litter of the dominant species showed a similar seasonal variation over the year except for N in P glehnii and A. hirsuta. The nutrient fluxes for all elements analyzed were greatest on riparian zone and lowest in wetland zone. Nutrient fluxes via litterfall followed the decreasing sequence： N （11-129 kg.hm-2.aq） 〉 Ca （9-69） 〉 K （5-20） 〉 Mg （3-15） 〉 P （0.4-4.7） for all stands. Significant differences were found in litterfall production and nutrient fluxes among the different landscape components. There existed significant differences in soil chemistry between the different landscape zones. The consistently low soil C：N ratios at the riparian zone might be due to the higher-quality litter inputs （largely N-fixing alder）.对北海道北部北海道大学雨龙试验林内的森林流域,不同景观地段的森林冠层凋落物及其养分归还量进行了为期2年的研究。湿地带分布着红皮云杉纯林,河岸带是以毛赤杨和柳树为优势树种的落叶阔叶林,而高地则分布着以白桦、大叶栎和萨哈林冷杉为优势树种的落叶阔叶与常绿针叶树混交林。湿地带、河岸带及高地森林的年平均凋落物量分别为1444、5122和4123 kg·hm-2,凋落物的高峰期出现在9-10月份,落叶量占年凋落物总量的73.4%-87.6%。除了红皮云杉和毛赤杨落叶的氮浓度无显著性季节变化外,其它优势树种落叶的养分浓度具有相似的季节变化规律。所分析的各养分元素归还量都是河岸带林分最高,而湿地带最低;各林分凋落物的不同养分归还量按其高低排序都表现出:N(11-129kg·(hm-2·a))>Ca(9-69)>K (5-20)>Mg(3-15)>P (0.4-4.7)。可见,不同景观地段的森林凋落物量及其养分归还量存在显著差异。不同景观地段的土壤化学性质有明显不同,河岸带土壤的低碳氮比可能是高质量落叶(主要是固氮树种毛赤杨)所致。

关 键 词：Landscape LITTERFALL Nutrient cycling Soil chemistry Temperate forest 

分 类 号：S714[农业科学—林学] S718.5