密度和施肥调控对巨龙竹新竹生长及生物量特征的影响

Effects of density and fertilization on growth and biomass characteristics of newly grown Dendrocalamus sinicus

【目的】探索择伐留竹密度和施肥量对巨龙竹新竹生长和生物量积累及分配特征影响,为巨龙竹高效培育和科学经营管理提供依据。【方法】以滇西南巨龙竹为研究对象,设计择伐留竹密度(7、15、25、35株/丛)和有机肥施用量(0、40、80、120 kg/丛)的2因素4水平正交试验,通过每木检尺和破坏性收获调查23种新竹生长形态、生物量积累及分配特征指标,采用方差分析、主成分分析和加权-模糊数学隶属函数法综合分析16种试验处理组合巨龙竹新竹生长及生物量特征差异。【结果】(1)不同试验处理巨龙竹平均每丛新竹数量1.0~7.8株、胸径17.2~19.9 cm、竹高29.0~29.9 m、枝下高14.8~16.3 m;单株新竹各构件生物量:总69.63~98.13 kg、地上58.22~80.42 kg、地下11.41~17.71 kg、秆48.94~60.37 kg、枝3.71~12.04 kg、叶1.55~9.10 kg;竹丛新竹各组分生物量:总69.63~678.20 kg、地上58.22~543.62 kg、地下11.41~134.58 kg、秆48.94~467.89 kg、枝5.69~48.04 kg、叶3.60~28.69 kg;新竹构件(组分)生物量分配比重:地上79.47%~83.62%、地下16.38%~20.53%、秆60.41%~74.87%、枝5.12%~12.27%、叶2.11%~9.26%、根冠比0.20~0.26、出叶强度0.40~0.75。(2)择伐留竹密度和施肥量对巨龙竹新竹生长形态、生物量积累及分配特征影响显著。相同密度,新竹生长形态及生物量积累特征指标总体上随施肥量增加而提高,地下、枝、叶的生物量比重提高,而地上、秆的生物量比重降低;相同施肥量,新竹生长形态及生物量积累特征指标总体上随密度增加而先提高后降低(峰值转折点:25、15株/丛),地下、秆的生物量比重提高、而地上、枝、叶的生物量比重降低。(3)不同试验处理组合巨龙竹新竹生长和生物量特征综合评价得分及排名,单株(前3):T^((7+120))(0.457)、T^((15+120))(0.390)、T_(3)^((7+80))(0.389);竹丛(前3):T_(12)^((25+120))(0.456)、T_(g)^((15+120))(0.447)、T_(4)^((7+120))(0.424)。【结论】综合比较,巨龙竹择伐留竹密度和有机肥施用量宜控制在25株/丛和120 kg/丛,利于新竹生长和生产力提高。

[Objective]The effects of cutting-remaining bamboo density and organic fertilizer amount on newly grown bamboo growth,biomass accumulation and distribution characteristics of Dendrocalamus sinicus were explored,providing a basis for the cultivation and management of D.sinicus.[Method]A two-factor and four-level orthogonal experiment was designed(cutting-remaining bamboo density:7,15,25,35 tree/cluster.organic fertilizer amount:0,40,80,120 kg/cluster)and 23 indexes of young D.sinicus growth and biomass characteristics were measurand for evaluating the density and ferilization effects of 16types of experimental treatment combinations by variance analysis,principal component analysis and weighting-fuzzy mathematics in southwestern Yunnan Province of southwestern China.[Result](1)On average,young bamboo amount:1.0-7.8 tree/cluster,DBH:17.2-19.9 cm,total length:29.0-29.9 m,clear length:14.8-16.3 m;biomass of each component of individual newly grown bamboo:total biomass each tree:69.63-98.13 kg,aboveground biomass:58.22-80.42 kg,underground biomass:11.41-17.71 kg,stalk biomass:48.94-60.37 kg,branch biomass:3.71-12.04 kg,leaf biomass:1.55-9.10 kg;biomass of each component of newly grown individual bamboo cluster:total biomass:69.63-678.20 kg,aboveground biomass:58.22-543.62 kg,underground biomass:11.41-134.58 kg,stalk biomass:48.94-467.89 kg,branch biomass:5.69-48.04 kg,leaf biomass:3.60-28.69 kg;proportion of biomass allocation of components of newly grown bamboo:aboveground biomass:79.47%-83.62%,underground biomass:16.38%-20.53%,stalk biomass:60.41%-74.87%,branch biomass:5.12%-12.27%,leaf biomass:2.11%-9.26%,root-shoot ratio:0.20-0.26,leafing intensity:0.40-0.75.(2)The effects of cutting-remaining bamboo density and organic fertilizer amount on bamboo growth and biomass characteristics of D.sinicus were significant.At the same cutting-remaining bamboo density and as the organic fertilizer amount increased,the indexes of young D.sinicus growth and biomass were increased,the biomass distribution proportions of underground,branch and leaf were increased and the biomass distribution proportions of aboveground and stalk were decreased.At the same organic fertilizer amount and as the cutting-remaining bamboo density increased,the indexes of young D.sinicus growth and biomass were increased firstly and then decreased(peak turning point:25,15 tree/cluster),the biomass distribution proportions of underground and stalk were increased,while the biomass distribution proportions of aboveground,branch and leaf were decreased.(3)The growth and biomass characteristics of D.sinicus biomass under different experiment treatments were evaluated.Stalk-comprehensive score(the first three):T^((7+120))(0.457)、T^((15+120))(0.390)、T_(3)^((7+80))(0.389).Clustercomprehensive score(the first three):T_(12)^((25+120))(0.456)、T_(g)^((15+120))(0.447)、T_(4)^((7+120))(0.424).[Conclusion]The cutting-remaining bamboo density is 25 tree/cluster and the organic fertilizer amount is120 kg/cluster,which are helpful to facilitate bamboo growth and raise productivity of D.sinicus.