杉木皆伐更新杉木木荷混交林生长效益分析

Study on the Growth Effect of Cunninghamia lanceolata Clear-cutting to Renew C.lanceolata Schima superba Mixed Forest

于2021年,在福建省永安国有林场对杉木人工林(1代)皆伐后更新的32年生的杉荷混交林和杉木纯林(2代)的生长状况进行调查分析。结果表明:32年生的8杉2荷人工混交林中,杉木平均树高20.1 m、胸径25.8 cm、单株立木材积0.4727 m3,林分蓄积量425.43 m3·hm^(-2),达到杉木最适宜区Ⅰ级立地速生丰产林大径材生长量指标;比前茬相同林龄的杉木纯林平均树高(20.5 m)、平均胸径(26.1 cm)和单株立木材积(0.4923 m3),分别减少2.0%、1.1%和4.0%,但二者间差异不显著;比连栽杉木(2代)纯林平均树高(18.0 m)、平均胸径(23.6 cm)、单株立木材积(0.3628 m3)和林分蓄积量(392.89 m3·hm^(-2)),分别增加11.7%、9.3%、30.3%和8.3%,二者间差异达极显著;杉木大径木占51.7%,比杉木纯林(2代)增加17.0%。表明杉木皆伐更新杉荷混交林有利于杉木大径材培育,是杉木2代林更新的良好模式。

For studying the growth effect,the clear-cutting renewal of C.lan ceolata plantation at Yong’an national forest farm of Fujian were inves tiged.T he results showed that 32-year-old artificial mixed forest of 8 C.lan ceolata wi th 2 S.Superba,the average height,DBH and stand volume ofC.lanceolata were 20.1 m,25.8 cm,0.4727 m^(3),and stand stock was 425.43 m^(3)·hm^(-2),w hich reac hed the growth index of large diameter wood in the most suitable area of C.lanceolataⅠsite class rapid growth and high yield forest.The av erage height(20.5 m),average DBH(26.1 cm)and stand volume(0.4923 m^(3))of C.lance olata pure forest with the same stand age were decreased by 2.0%,1.2%and 4.0%,respectively,but the difference betwee n the two was not significant.Compared with the average height(18.0 m),aver age DBH(23.6 cm),st and volume(0.3628 m^(3))and stand stock(392.89 m^(3)·hm^(-2))of C.lanceolata pure forest(second goneration),the averag e height 11.7%,9.3%,30.3%and 8.3%increased,respectively,and the diff erence between the two was extremely significant.The mixed forest of 8 C.anceolata and 2 S.superba(second generation forest)was beneficial to the cultivation of large-diameter wood of C.lanceol ata,accounting for 51.7%,which was 17.0%h igher than that of pure forest of C.lanceolata(second generati on forest).It was a good model for the regeneration of the second generation of C.lan ceolata forest to build the mixed forest of C.lanceolataand S.schima after the main clear-cutting of C.lanc eolata.