宜昌市郊不同龄级柏木人工林下植物组成与多样性变化

对宜昌市郊3个不同龄级柏木人工林林下植物物种组成和多样性变化的研究,结果表明,从幼龄林、中龄林到近熟林,林下灌木层由耐旱及强阳性种趋向耐旱性较强及中性种,且乔木种逐渐增加;林下草本层由以栗褐苔草和铺地龙为主趋向以蕨类为主;灌木层和草本层物种数量、香农—威纳指数、均匀度指数均呈增加趋势,而生态优势度呈下降趋势。说明实施封育恢复后柏木人工林呈进展演替趋势,但仍处于演替早期阶段。

Changes of species composition and diversity in different age -classes of undergrowth vegetations in Cupressus funebris plantations in Yichang suburb

Changes of species composition and diversity in different age-classes of undergrowth vegetations in Cupressus funebris plantations in Yichang suburb were studied in this paper.The results showed that,from young,half mature to near mature plantations,dominant species of shrub layer changed from drought-tolerant and strong intolerant trees to relatively drought-tolerant and neutral,and tree species increased.Dominant species of herb layer changed from Carex brunnea and Ficus tikoua to Pteridophyte.Number of species,Shannon-Wiener diversity index and evenness increased gradually,while ecological dominance decreased gradually.It is suggested that after vegetation restoration,Cupressus funebris plantations incline to process succession,but it is still at the early succession stage.