Study on water and mineral cycling in forest and deteriorated forest ecosystem in southern China.

1987年在江西省进行了严重侵蚀地和天然万年青阔叶林森林生态系统水、矿物质循环的森林生态学研究。1988年对国内的研究结果进行了讨论。首先，所有日本成员于9月9日在京都聚会。1988年，提交每个主题的结果并进行讨论。第二，G博士。1988年10月，岩坪先生作为工作人员访问中国，与中方人员讨论了我们的讨论结果。第三，1988年12月至1989年2月，首席研究员与部分日本成员就总结报告进行了再次讨论。最后，第一份报告的草稿于1988年3月中旬准备就绪。在严重侵蚀区，在马尾松幼林设置试验小区，研究了凋落物和林下植被清除及施肥对马尾松林分土壤肥力的影响，并对影响马尾松林分土壤肥力的主要因素进行了分析 关于我们 土壤的恢复率。所研究的松林生物量与江西省松林最贫瘠的立地相当。叶片生物量很低，林下植被很薄，很差。这意味着人类的影响仍然活跃在这一领域。土壤_0层、碳、氮和有效矿物的积累也很差。在九连山天然万年青阔叶林中，建立了自然保护区内的水、矿物质循环研究小流域。该流域植被可分为3种类型，即栲林、木荷林和松林。北方坡的低坡主要发育锥树林。松树林位于山坡或山脊上，土壤通常较浅且干燥。木荷林发育在两者之间的中间部位。在低坡的锥栗林和木荷林中设置两个样地，研究养分的内循环。利用异速生长关系估算了林分生物量。地上部分分别为396和308 t/ha，断面积分别为48.6和42.3 m^2/ha。干生长量分别为10.8和9.9t/ha·a。氮素积累量高于日本万年青阔叶林。研究区土壤属“红黄壤”。矿质土壤的碳积累量为53 ~ 90 t/ha。施氮量为3.4 ~ 8.9t/hm 2，70 cm。土壤交换性钙和速效磷含量较低。树木和土壤的总蓄积量分别为氮7.1-10.0t/ha，钙1826- 2383 kg/ha，镁446- 562 kg/ha，九连山年平均降水量1825 mm，气温16.5 ℃，蒸发皿蒸发量865.4mm。温暖指数为136摄氏度。冬季的日气温波动幅度大于20 ℃，有时甚至低于0 ℃。气候条件与日本的光叶林不同。少

Forest ecological studies on water and mineral cycling through forest ecosystems were carried out in severely eroded land and in natural evergreen broadleaved forest in Jiangxi Provinco, China, 1987.In 1988, the discussions were carried out on the results obtained in China. first, all japanese member got together in Kyoto on sept. 1988, to present the results of each subject and to discuss. Second, Dr. G. Iwatsubo, one of the staff member, visited china to talk about our result of discussion with the member of Chinese side, on Oct. 1988. Third, head investigator discussed again on the summerized report with some of Japanese member from Dec. 1988 to Feb. 1989. Finally, the draft of the first leport was prepared on middle of March 198.. This draft will be published soon.The outline of the draft is as follows;In severely eroded area, the experimental plot were set up in young pine(pinus massoniana) stands for investigate the effect of litter and undergrowth removal and fertilization on th … More e rate of recovery of soil. The biomass of pine stands studied were equivalent to that of the poorest site of pine forest in Jiangxi Province. The leaves biomass was very low and undergrowth was very thin and poor. This implies that the human impacts are still active in this area. The accumulation of _0 layer, and of carbon, nitrogen and available minerals in soil are also very poor. There was no evidence of soil recovery.In natural evergreen broadleaved forest at Jiulianshan, the small experimental watershed for the studies on water and mineral cycling was set up in nature reserve area. the vegetation in this watershed was classified into three types, that is, castanopsis forest, Schima Forest and Pine forest. Castanopsis forest developed mainly on lowerslope of northern slope. Pine forest was on upperslope or ridge where soil is usually shallow and dry. Schima forest develop on the intermediate site between above two. Two plots were set up in Castanopsis forest and Schima forest on lowereslope for investigate the internal cycle of nutrients. The biomass of the stands was estimated using the allometoric relationships. The above ground part was 396 and 308 t/ha and basal area was 48.6 and 42.3 m^2/ha, respectively. the stem increment was estimated as 10.8 and 9.9 t/ha yr.The chemical analysis of evergreen broadleaved trees was carried out and mineralmass of trees was estimated. Nitrogen accumulation was higher than that of the evergreen broadleaved forest in Japan. Soil in the studied area could be identified as "Red Yellow Soil". The accumulated carbon in mineral soil is ranged from 53 to 90t/ha. 70cm, and that of nitrogen was from 3.4 to 8.9t/ha, 70cm. The amount of exchangeable Ca and available P were rather low. The total accumulations, sum of trees and soil, are 7.1-10.0t/ha for nitrogen, 1826-2383kg/ha for Ca and 446-562kg/ha for Mg, respectively.At Jiulianshan, the annual mean precipitation, temperature and pan evaporation are 1825mm, 16.5 c and 865.4mm, respectively. The warmth index is 136 c mo.. The daily temperature during the winter has wider fluctuations than 20 c, and sometimes it decrease below 0 c. The climatic condition differ from that in the Japanese lucidophyllous forest. Less