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将浙江省杉木公益林划分为3个发育阶段:≤10 a为幼龄林;11~20 a为中龄林;>20 a为成熟林。对杉木(Cunninghamia lanceolata)优势林和含杉木混交林的三个发育阶段的乔木层、下木层和草本层的植物多样性进行比较研究。结果表明:杉木优势林的乔木层植物多样性指数都随时间缓慢上升(<15%),成熟林乔木层的异质性和均匀性高于草本层,幼龄林下木层多样性不高,物种数和异质性也都随时间缓慢上升(<5%),下木层均匀性在中龄以后稳定,杉木优势林随着林龄的增加,郁闭度相应增加使得草本层的Gleason指数从2.62下降到1.68;含杉木混交林封山育林后幼龄林下木层植物多样性最高,中龄林的物种数、异质性最低,均匀度随时间逐渐降低,各层植物多样性指数在各个发育阶段都表现为下木层>乔木层>草本层,仅有草本层Gleason指数中幼龄林阶段较高例外;在各个发育阶段杉木优势林的乔木层和下木层的植物多样性都不如含杉木混交林,优势林草本层的物种丰富度、异质性和均匀性指数幼龄林阶段都高于含杉木混交林,中龄林阶段接近,在成熟林阶段都比含杉木混交林低;总体而言,杉木优势林的植物多样性不如相同发育阶段的含杉木混交林。
The commonweal forests in Zhejiang Province are divided into three development stages: ≤10 a for young forest; 11-20 a for middle-aged forest;> 20 a for mature forest. The plant diversity of arbor, understory and herb layers in three developmental stages of dominant Cunninghamia lanceolata forest and mixed forest containing Cunninghamia lanceolata were compared. The results showed that the plant diversity index of tree layer in Cunninghamia lanceolata forest increased slowly with time (<15%). The heterogeneity and uniformity of tree layer in mature forest were higher than that in herb layer, while the diversity of tree layer in young forest was not high , The number of species and heterogeneity also increased slowly with time (<5%). The uniformity of understory layer was stable after middle age. With the increasing of age, the canopy density increased correspondingly. The Gleason The index decreased from 2.62 to 1.68. The plant species diversity of the young layer was the highest in the young-aged stands after afforestation with mixed forests of Chinese fir, while the species number and heterogeneity of the middle-aged stands were the lowest. The evenness decreased with time. The plant diversity index All developmental stages showed as subgranular layer> arbor layer> herb layer, with only the exception of the youngleaf forest stage in the Gleason index of the herbaceous layer. In both developmental stages, the plant diversity of arborous layer and subalpine layer As for the mixed forest with Chinese fir, the species richness, heterogeneity and evenness index of dominant species were higher than that of the mixed forest containing Chinese fir, while the stage of middle-aged forest was close. In mature stage, Low; Overall, plantations of superior forest of fir Not as good as the same stage of development with the diversity of the Mixed Forest.