The Long Term Monitorring on Tree Phenology and Acid Deposits

为了评价森林的环境界线，1992.1日本大学森林会议制定了一项长期监测项目。对大学森林100个林分主要乡土树种的物候学进行了调查。为评价林分幼龄因子，将林木纳入调查范围。日本山毛榉(Fagus crenata BL.)从日本不同的地区采集，在9个大学森林和其他4个林分种植，于1990-‘91年。从大学森林的26个林分种植的精选品种杨树(I-245杨)的插条上长出的树苗。在大学森林的多个点观测到了降雨、穿透雨和树干径流的化学条件：(1)森林降水pH值的最大频率值在4-5之间，接近日本环境厅报道的平均值。研究发现，森林降雨和降雪的pH值受局部人类活动的影响。(2)穿透雨和树干径流的pH值低于雨量，而EC大于雨量。(3)总体上，针叶树干径流的pH值高于阔叶树。(4)秋季和长时间无雨后，树干径流的离子浓度升高。裸露林小样地(20*20m)土壤的pH值和化学性质随地点和季节的变化较为复杂。1992年编写的这份监测手册于1995年重新编写，日本大学森林会议于1995年成立了这一项目的新委员会。

To evaluate the environmental deline in forests a long term monitorring project was made by he Japanese Conference of University Forests in 1992.1. The tree phenology of main native spcies were investigated at one hundred stands in unversity forests. To evaluate the babitat factors of the stands, follwing trees included for investigation.a. Japanese beech (Fagus crenata BL.) which collected from different areas in Japan, planted at nine university forests and other four stand, in 1990-'91.b. Saplings grown up from cuttings of a select breed aspen (Populus I-245) planted at twenty-six stands of university forests.2. Chemical condions of rainfall, throughfall and stemflow were observed at many points of unversity forests.(1)The most frequency values of the pH of rainfall in forests ranged 4-5, nearly the average data reported by Environment Agency of Japan. There were found values of the pH of rainfall and snowfall in forests are influenced by local human activities.(2)The pH of the throughfall and stemflow were lower and EC of them were greater then the values of rainfall.(3)In generally, the pH stemflow on coniferous trees were greater than the values on broadleaved trees.(4)The ionic concentration of the stemflows increased in autumn and at the after long rainless period.3. The pH and chemical properties of soils at small plots (20*20m) in nutural forests varied complicatedly by location and season.4. The manual of this monitorring composed in 1992 was rewritten in 1995, and new a committee for this project of the Japanese Conference of University Forests started in 1995.