摘要
试验研究表明，马尾松在其迹地上造林，成活率比在荒山造林的低２０．９％，其一、二年生幼林的高生长比松一代分别低１３．４％和１５．２％。用荒山土、马尾松连栽（即松二代）土、松成林土与杉松轮栽土，经灭菌与不灭菌处理培育马尾松苗试验，其苗高、主根长、单株鲜重与干重及菌根的形成，均以荒山上显著高于松二代上和松成林土；尤其是菌根形成数，灭菌的荒山土比松二代土与松成林土高８０％以上。灭菌后已排除微生物的影响，这种差异可能是松二代土与松成林上含有抑制菌根形成的植物毒素所致。从土壤分析结果表明，松二代上与松成林土的养分含量、ｐＨ值、代换性的Ｃａ２＋／Ａｌ３＋都低；土壤微生物总数以及细菌、好气固Ｎ菌、氨化细菌的数量都减少，而真菌、放线菌和分枝杆菌的数量都增加；土壤的蛋白酶、蔗糖酶与过氧化氢酶的活性降低，但多酚氧化酶的活性却增高。所有这些都与马尾松连栽生产力下降有关。
The survival percent of replanting Pinus massoniana decreased by 20.9%,the high growth of 1-and 2-yr-old replanting stands decreased by 13.4% and 13.5%,respective ly,the diameter growth of 2-yr-old's decreased by 6.12 % in comparing with the non-replanting stands.The growth and mycorrhizal formation of seedlings of P.massoniana grown on sterilized and non-sterilised soils were significantly better on soils from waste land than on soils from the replanting stand and mature pine stand.The effect of sterilized soils from the later two stands on seedling mycorrhizal formation was subsequently tested under aseptic condition so that any complicating microbial factors were eliminated.It is postulated that the mycorrhizal formation retardation was caused by phytotoxin presented in the soils of replant ing and mature pine stands. The results of soil analysis showed that in the replanting and mature pine stands comparing to the waste land,the nutrient content,pH,Ca2+/Al3+ rate,total number of soil microorganism and the activity of soil enzymes (except the polyphenol oxydase)were significantly decreased.These are causal agents of lower productivity of re planting pine stands.
关键词
马尾松
连栽
幼林
生产力
生长
Pinus massoniana
replanting
young stands
productivity
phytotoxin
