江西省第一代人工杉木林土壤退化的研究

A Study on the Soil Deterioration of the First Generationof Artificial Fir Plantation in Jiangxi Province

本文通过对江西省常绿阔叶林和在其砍伐后更新的第一代杉木人工林地土壤性状的广泛调查研究发现，与常绿阔叶林比较，杉木人工林在幼林期地表无枯枝落叶层形成。即使是杉木成林，其林下枯枝落叶层贮量也仅为前者的５７．０８％，且构形简单，没有盘根层的形成；由于土壤缺少覆盖，杉木幼林期土壤侵蚀严重，并使土壤剖面逆向发育，且以花岗岩地区最为严重；研究还发现，杉木人工林土壤养分状况恶化，表现为土壤有机质，全Ｎ量，碱解Ｎ和速效Ｐ含量以及土壤Ｃ．Ｅ．Ｃ的极显著下降；研究同时发现．杉木人工林下土壤的物理性状也明显恶化，土壤的砾石和砂粒含量极显著增加，而粘粒含量极显著下降，土壤容重随之增加。可见，江西省第一代杉木欠工林地的土壤已经严重退化。本文认为，使第一代杉木人工林土壤退化的主要原因为：不合理的造林方式，粗放的抚育和集材方式，单一的林分组成以及缺乏足够的投入。

After broadly investigating and studying of the soil of the artificial fir plantation andthe even-green and broad-leaved forest in Jiangxi province,it was found that there was no litterlager fromed under the young artificial fir plantation. Even the plantation have been growing up.,the litter under that plantation weighs only 57.08% of that the even-green and broad-leaved forest.In addition,the litter layer tinder artificial fir is mostly fresh dead leaves and branches and noroot-mat formed in it. Serious soil erosion is observed under the young artificial fir plantation dueto lacking of covering on the soil surface,in turn it brings about reverse development of the soilprofile. And the situation accer most seriousely in the granit rock area.It is also indicated that thesoil organic matter,total N,available N,available P and C.E.C under the artificial fir plantationreduced remarkedly compared with the broad-leaVed forest,and the soil physical properties worsen as well. All these results show that the soil of artificial fir plantation deteriorated greatly. Itwas regarded that the reasons letting to the deterioration of the soil of the first generetion artificial fir plantation include: irrgational methods of regeneretion,careless manegement of the froestand ways of collecting wood,monotonous forest composition,and lacking of sufficient input.