| 摘要: |
| 【目的】研究不同混交模式桉树人工林的林分生长状况、凋落物量和土壤养分含量，探寻桉树种植业的可持续经营模式。【方法】在广西西南部地区，选取巨尾桉纯林及其分别与降香黄檀、望天树、格木和红椎混交的试验林为研究对象，采用典型样地调查法，测定各树种的胸径、树高、枝下高和冠幅，计算单株材积和林分蓄积量；在各样地设置3个取样点，采集凋落物和表层土壤(0~20 cm)，测定凋落物量及土壤pH值和养分含量。【结果】(1) 混交林巨尾桉的胸径(除巨尾桉+降香黄檀混交林外)、枝下高(除巨尾桉+降香黄檀混交林外)、冠幅和单株材积均显著高于巨尾桉纯林(P＜0.05)，但树高生长差异性不显著。(2) 不同混交模式中，巨尾桉蓄积量表现为巨尾桉纯林(126.89 m3/hm2)＞巨尾桉+红椎混交林(114.02 m3/hm2)＞巨尾桉+格木混交林(111.06 m3/hm2)＞巨尾桉+望天树混交林(109.82 m3/hm2)＞巨尾桉+降香黄檀混交林(107.23 m3/hm2)，混交树种蓄积量表现为红椎(25.72 m3/hm2)＞望天树(19.01 m3/hm2)＞格木(14.85 m3/hm2)＞降香黄檀(9.35 m3/hm2)。(3)混交林地凋落物总存量显著高于巨尾桉纯林，且其半分解层凋落物存量均大于未分解层，而巨尾桉纯林则相反。(4)混交林地表层(0~20 cm)土壤pH值及土壤有机质、速效N、速效K、全N、全P和全K含量均显著高于巨尾桉纯林，各林分间速效P含量差异性不显著。【结论】不同混交模式对桉树林分生长、凋落物量和土壤养分的影响显著。从林分质量和产量的角度考虑，巨尾桉与红椎混交模式在促进林分生长、提高凋落物量和土壤质量方面更具优势。 |
| 关键词: 桉树 人工林 林分生长 凋落物 土壤养分 混交模式 |
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| 基金项目:广西科技重大专项“桉树用材林质量精准提升关键技术研究与示范”(桂科AA17204087-6) |
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| Effects of different mixing patterns on growth,litter production and soil nutrients in Eucalyptus plantations |
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ZHANG Pei,PANG Shengjiang,YANG Baoguo,et al
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| Abstract: |
| 【Objective】This paper studied the growth of different tree species,litter production and soil nutrients in Eucalyptus plantations with different mixing patterns to provide basis for scientific cultivation and sustainable management of Eucalyptus plantations.【Method】The single species plantation of Eucalyptus grandis×E.urophylla and its mixed species plantations with Dalbergia odorifera,Parashorea chinensis,Erythrophleum fordii and Castanopsis hystrix in Southwest Guangxi were selected.The method of typical plots was used to measure diameter at breast height (DBH),height,height under branches and crown width of each tree species and calculate individual volume and stand volume.Three sampling sites in the center of each plot were selected to collect litter and soil samples at the top with depth of 0-20 cm for measuring soil pH and soil nutrient content.【Result】(1) The DBH (except for mixed forest of Eucalyptus grandis×E.urophylla and Dalbergia odorifera),height under branch (except for mixed forests of Eucalyptus grandis×E.urophylla and Dalbergia odorifera),crown diameter and individual tree volume growth in mixed forests were significantly higher than pure forest (P<0.05),while height growth had no significant difference (P>0.05).(2) Among different mixing patterns,the volumes of Eucalyptus grandis×E.urophylla forests were in the order of Eucalyptus grandis×E.urophylla pure forest (126.89 m3/hm2)＞mixed forest of Eucalyptus grandis×E.urophylla and Castanopsis hystrix(114.02 m3/hm2)＞mixed forest of Eucalyptus grandis×E.urophylla and Erythrophleum fordii(111.06 m3/hm2)＞mixed forest of Eucalyptus grandis×E.urophylla and Parashorea chinensis (109.82 m3/hm2)＞mixed forest of Eucalyptus grandis×E.urophylla and Dalbergia odorifera (107.23 m3/hm2).The volumes were in the order of Castanopsis hystrix (25.72 m3/hm2)＞Parashorea chinensis (19.01 m3/hm2)＞Erythrophleum fordii (14.85 m3/hm2)＞Dalbergia odorifera (9.35 m3/hm2).(3) Mixed forests had higher total litter stock than pure forest.In mixed forests,semi-decomposed litter layer was thicker than that of undecomposed layer,while it was the opposite in pure forest.(4) Soil pH value and contents of soil organic matter,available N,available K,total N,total P and total K in mixed forests were significantly higher than those of in pure forests,while there was no significant difference in available P among all forests.【Conclusion】Different mixing patterns had significant impacts on growth,litter production and soil nutrients of Eucalyptus plantations.Considering stand quality and yield,the mixed forests of Eucalyptus grandis×E.urophylla and Castanopsis hystrix had more advantages in stand growth,improvement of litter and soil quality. |
| Key words: Eucalyptus plantation stand growth litter soil nutrient mixing pattern |
