杉木连栽回心土造林技术研究

The Study on the Attorestation Technology of Growing Cunnighamia lanceolata Continually with Returned Inner Soil

杉木幼苗盆栽试验表明，杉木逢栽0～20cm表层土，盆栽杉苗成活率只有24.4％，生长量比同层头栽土下降41.8％．经连栽与头栽造林试验，结果表明连栽林地杉木保存率比头栽下降13．2％，连栽杉木当年幼树高仅21．6cm，6年生树高也仅214．9cm，而头栽杉木当年、6年生树高分别达37．4cm和367．0cm．采用回心土造林，连栽杉木保存率提高16.8％，树高生长量提高37．9％～60.2％；营造1．53hm2回心土示范林，成活率和生长量均显著高于常规造林.研究认为，不利于杉木连栽生长的限制因子集中在0～20cm表土层，是导致杉木连栽成活率和生长量下降的一个重要因素．

According to the experiment on growing young Cunnighamia lanceolata seedlings in pots, the survival rate of growing Cunninghamia lanceolata seedlings in pots with 0~ 20cm surface soil of growing Cunninghamia lanceolata continually is only 24. 4%. The amount of growth drops 41. 8% in contrast with that ofgrowing Cunninghamia lanceolata with the first grown soil in the same layer. By foe experiment of the continual and the first afforeslation, the survival rate of Cunninghamia lanceolata of the continually grown woodlanddrops 13. 2% in contrast with that of the first grown woodland. The height of the same year young trees ofgrowing Cunninghamia lanceolata continually is only 21. 6cm. The height of 6 years old trees is only214. 9cm. The height of the same year and 6 year old trees of growing Cunninghamia lanceolata for the firsttime is respectively 37. 4cm and 367. 0cm. On the afforestation with returned inner soil, the survival rate ofgrowing Cunninghamia lanceolata continually raises 16. 8%. The amount of height growth raises 37. 9 %~60. 2 %. When 1. 53hm2 exemplary forest with returned inner soil has been grown,both the survivial rale andthe amount of growth are bigger than those of normal afforestation. The research shows that the limiting factors or noxious material which is disadvantageous to the growth of growing Cunninghamia lanceolata continually gathers in 0~20cm surface soil. It is an important factor which makes survival rate and growth amoundrop under growing Cunninghamia lanceolata continually.