杉木人工林套种不同树种对林分生长和植物多样性的影响

Effects of Different Interplanted Species on Growth and Plant Diversity in Cunninghamia lanceolataPlantations

研究杉木林间伐后,于林下套种香梓楠、华盖木、红豆杉、缅茄4种树种,对比未套种杉木纯林,分析套种后林分的生长状况和植物多样性,为杉木人工林近自然改造与可持续经营提供参考依据。结果表明:香梓楠、华盖木、红豆杉与杉木形成异龄复层混交林,香梓楠胸径、树高生长量及保存率最高,分别达到10.5 cm、9.8 m、82.22%,显著高于其他树种;缅茄胸径、树高生长量及保存率最低,分别为2.4 cm、1.7 m、15.66%。套种缅茄、香梓楠、华盖木对杉木胸径有促进作用,套种缅茄后杉木树高显著提高。5种杉木林分林下植被中共出现33科52属60种植物,草本层出现植物15科25属27种,以禾本科和菊科植物为主;灌木层出现植物18科27属33种,以大戟科、茜草科和桑科植物为主;4种杉木混交林林下出现植物比杉木纯林增加24种。杉木×香梓楠、杉木×华盖木林下植物多样性比杉木×缅茄和杉木纯林显著提高。综合杉木间伐后套种不同树种表现,套种香梓楠对林分生长和植物多样性更具优势,可作为今后杉木近自然改造的参考模式。

Michelia gioii,Pachylarnax sinica,Taxus wallichiana and Afzelia xylocarpa were interplanted into a thinned Cunninghamia lanceolata plantation.Comparing with a pure C.lanceolata plantation without interplanting,the growth and plant diversity of the interplanted plantation was analyzed,with the aim of providing a reference for close-to-nature transformation and sustainable management of C.lanceolata plantations.The results showed that the growth of M.gioii,P.sinica,and T.wallichiana formed different age,multi-layered forests with C.lanceolata.Thediameter at breast height,height,and preservation rate of M.gioii was the highest,and significantly higher than other interplanted species,reaching 10.5 cm,9.8 m,and 82.22%,respectively.The diameter at breast height,height,and preservation rate of A.xylocarpa was the lowest,at 2.4 cm,1.7 m,and 15.66%,respectively.Interplanting with A.xylocarpa,M.gioii and P.sinica had a promotion effect on the breast height diameter and height of C.lanceolata trees,whilst the height significantly increased only for interplanting with A.xylocarpa.There were 60 species in 52 genera of 30 families of undergrowth plants in 4 interplanted and 1 pure C.lanceolata stands.There were 27 species in 25 genera of 27 families in the herb layer,with species of the Gramineae and Asteraceae families being predominant this layer.There were 33 species in 27 genera of 18 families in the shrub layer,with species of Euphorbiaceae,Rubiaceae and Moraceae families being predominant in this layer.The species number of four mixed forest types of C.lanceolata were more than pure forests of C.lanceolata.The diversity of understory plants in the C.lanceolata×M.gioii,and C.lanceolata×P.sinica forests were significantly higher compared to the forests of C.lanceolata×A.xylocarpa and pure C.lanceolata plantations.The performance of different interplanted tree species after comprehensive thinning of C.lanceolata showed that interplanted M.gioii had more advantages in stand growth and plant diversity,and could be used as a reference model for close-to-nature transformation of C.lanceolata plantations in the future.