龙山县日本落叶松人工林林分生长与结构调查

Investigation on stand growth and structure of Larix leptolepis plantation at Longshan County

对龙山县日本落叶松人工林林分生长与结构进行调查，结果表明：龙山县中山区日本落叶松人工林表现良好，林龄12—13年平均胸径8．43cm，大小相差0．9倍；平均树高6．34m，大小相差1．1倍；平均蓄积12．84m3／bm2，大小相差34．6倍。该人工林为结构单一的纯林，日本落叶松株数97．2％、阔叶树株数2．8％；天然阔叶树仅为响叶杨、檫木及光皮桦等，优质树种缺乏，需人工补植优质阔叶树。日本落叶松人工林稳定性较强，2008年特大冰冻灾害后保存正常植株86．4％；日本落叶松林可划分为“单一纯林”及“较稀疏的人工林”两种类型，宜开展近自然改造。

An investigation was made on stand growth and structure of Larix leptolepis plantation at Longshan County. The results showed that, the plantation of Larix leptolepis performed well on middle altitude mountainous area at Longshan County. The average diameter at breast height （DBH） was 8.43cm for plantation with 12a - 13a, and the DBH of the biggest individual was 0. 9 times of that of the smallest one. Average height of all individuals was 6. 34m, and the height of the biggest individual was 1. 1 times of that of the smallest one. Average volume was 12. 84 m3/hm2 , and the tree vol- ume of plantation with the highest production was 34. 6 times of that with the lowest production. The plantation in this area was pure with only one wood species. Among them, individuals of Larix leptolepis accounted for 97.2%, while individu- als of broad leaf species accounted for only 2. 8%, which included Populus adenopoda, Sassafras tzumu and Betula lumi- nifera, etc. It lacked for high quality broad leaf species, so planting artificially is needed. The plantation of Larix leptole- pis had a property of strong stability. It was a good example that there were 86.4% of normal individuals still existed after the huge ice disaster in 2008. The plantations of Larix leptolepis could be divided into two types, one was pure plantation, and another was sparse plantation. All of them are ＂fit for improving in the way of nature-imitation.