农田防护林更新技术研究

农田防护林更新技术研究历时28年。先后采用带内、带侧、带间、原带皆伐四种更新方式,筛选出红皮云杉、樟子松、落叶松三种较为理想的更新树种。对于不超过10年营造的杨树林带,通过问伐采用带内更新,超过10年的采用带侧更新;对于已开始衰老,但尚能起防护作用的宽林带可采用原带一侧部分皆伐更新;对于成过熟林带,或防护作用甚微的残破林带,“小老树”,可采用原带皆伐更新;对于大网格林带可采用带间更新。带内更新应选择3年生的耐荫树种红皮云杉。带侧更新、原带一侧部分皆伐更新应选择4年生的红皮云杉,或4年生换床的樟子松。带间更新应选择速生的落叶松、樟子松搭配。

STUDY ON RENOVATION OF SHELTER BELT TO PROTECT FARMLAND

It has taken 28 years to study the renovation of shelter belt to protect farmland, four types of renovation as follows:(1) Planting within belt after cutting several original rows;(2) Planting by the side of original belt;(3) Pirating between two belts;(4) Clear cutting the original belt and planting in the site.The ideal species such as Picea koraiensis, Pinus sylvestris var. mongolice, Larix were selected. For under 10 years old poplar original belt could be apply the type (1), or over 10 years old one apply the type (2); the declined, wider belt could apply type (2); the residual, broken belt, or mature belt could apply type (4); the large lattice belt may be applied the type (3). In type (2), may be selected 3 years old Picea koraiensis; in type (2), may be selected 4 years old seedlings of Picea koraiensis, or transplanting bed seedlings of Pinus sylvestris var. mongolica; in type (3), could be selected the fast growing species as Larix, Pinus sylvestris var. mongolica and well composed.