杉木保留密度对杉阔异龄复层林生长量及土壤理化性质的影响  

Effects of retention density on the growth and soil physicochemical properties of multi-layered Cunninghamia lanceolata forests of different ages

作　　者：钱越 李铁华[1] 游美 李若楚 张心艺 QIAN Yue;LI Tiehua;YOU Mei;LI Ruochu;ZHANG Xinyi(Central South University of Forestry&Technology,Changsha 410004,Hunan,China)

机构地区：[1]中南林业科技大学,湖南长沙410004

出　　处：《湖南林业科技》2024年第3期36-43,共8页Hunan Forestry Science & Technology

基　　金：国家重点研发计划项目(2021YFD2201304)。

摘　　要：为解决杉木纯林地力衰退、生产力下降及生物多样性降低等问题,按近自然经营的原则改造杉木纯林为杉阔复层林。设定3种杉木保留密度,分别为A密度(525株·hm^(-2))、B密度(675株·hm^(-2))、C密度(975株·hm^(-2)),研究不同杉木保留密度对杉木及林下阔叶幼树年生长量、土壤物理及化学性质的影响。结果表明:B密度下,杉木单株材积增长量最高且显著高于C密度,每1hm^(2)杉木材积增长量显著高于A密度,阔叶幼树地径年均增量比C密度高25.3%,土壤的含水量显著高于A密度。在0~20cm土层,B密度土壤的有机质含量显著高于A、C密度,分别高出19.9%和34.5%;B密度下0~20、>40~60cm土层的碳氮比显著高于C密度;B密度下0~60cm土层的全磷含量和全钾含量均为最高。可得出如下结论:杉木保留密度为B密度(675株·hm^(-2))时,杉木胸径、树高、单株材积和每1hm^(2)杉木材积年均增量均最高;林下阔叶幼树地径年均增量最高,有利于杉木大径材的培育且几乎不影响单位面积杉木出材量;土壤具有最高的有机质含量和氮、磷、钾及其他矿质养分含量,能促进复层林杉木和林下阔叶幼树的生长。In order to solve the problems of soil fertility declining,productivity declining and biodiversity reducing,the pure Cunninghamia lanceolata forest was transformed into a broad-leaved multi-layered forest according to the principle of nearnatural management.Three retention densities of Cunninghamia lanceolata were set as density A(525 trees per hectare),density B(675 trees per hectare)and density C(975 trees per hectare),and the effects of different retention densities on the growth of Cunninghamia lanceolata and understory broad-leaved young trees,soil physical and chemical properties were studied The results showed that the individual volume growth of Cunninghamia lanceolata under density B was the highest and significantly higher than that under density,the growth of wood volume per hectare was significantly higher than that under density A,and the average annual growth of ground diameter of understory broad-leaved trees was 25.3%higher than that under density C.The water content of soil under density B was significantly higher than that under density A.In the O~20 cm soil layer,the organic matter content of soil under density B was significantly higher than that under density A and density C,with 19.9%and 34.5%higher than that,respectively.The C/N ratio of 0~20 and>40~60 cm soil layers under density B was significantly higher than that under density C.The total potassium and phosphorus contents of O~60 cm soil layer were the highest under density B.We could make the conclusion as follows:When the retention density of Cunninghamia lanceolata was density B(675 trees per hectare),the annual average increase of diameter at breast height,tree height,volume per tree and timber volume per hectare of Cunninghamia lanceolata were the highest,and the average annual increase of ground diameter of broad-leaved young trees under the forest was the highest,which was conducive to the cultivation of large-diameter Cunninghamia lanceolata and almost did not affect the yield of Cunninghamia lanceolata per unit area.When the re

关 键 词：近自然经营 复层林 人工林改造 地力衰退 阔叶幼树 

分 类 号：S791.27[农业科学—林木遗传育种]