施肥对毛竹生长量和秆形的影响

Growth and culm form of Phyllostachys pubescens with fertilization

为探讨施肥对毛竹Phyllostachys pubescens秆形结构影响的规律,并为竹林合理施肥提供依据,基于对浙江省龙泉市农户的农村参与式评估,调查建立以材为主两用毛竹林20 m×30 m标准样地38块(坡度小于30°),进行典型抽样选择推荐施肥(N∶P∶K=17∶8∶5,1 125 kg.hm-2,沟施,5 a)和不施肥(10 a)样地各7块,对比研究竹林生长量和秆形变化,建立节间长、胸高直径、秆质量分布、壁厚反映毛竹形态的回归方程。Ducan’s多重比较和显著性检验表明:施肥后毛竹林密度增加930株.hm-2,但秆质量比不施肥毛竹轻6.8%,均达到差异显著性水平;协方差分析和t检验显示,在相同的竹林密度下,秆高、材质量分布、壁厚、削尖度受施肥影响不显著(P>0.05)。因此,施肥经营后林分竹秆质量有所下降,但胸径和林分密度增加,林分水平的长期生物产量增加,合理施肥能提高毛竹林地生物产量和立地生产力。

This study was conducted to determine the effect of fertilization for Phyllostachys pubescens on the culm form and to help optimize fertilizer application. Based on a participatory rural appraisal （PRA） survey to households of Longquan City of Zhejiang, 38 pole-dominated dual-purpose （pole and bamboo shoots） standard plots （20 m x 30 m, site slope 〈 30°） were identified among which 7 plots were typical sampled for recom- mended fertilization stands （N ： P ： K = 17 ： 8 ： 5, 1 125 kg.hm-2, ditch-fertilizing, over 5 years） and for unfertilized stands （over 10 years） respectively. The pole growth between the recommended fertilized stands and unfertilized stands were compared and regression equations were developed for internode length versus DBH, pole weight distribution, wall thickness and taper to reflect Ph. pubescens culm form. Ducan＇s multiple comparisons and significance test showed that the density of fertilized stands was 930 culms .hm-2 higher than the unfertilized but the culm weight for fertilized stands was 6.8% lighter than the unfertilized, both reaching sig- nificant difference level. Covariance analysis and t-test showed insignificant difference of fertilization effect on pole weight distribution, wall thickness and taper （P〉0.05）. Therefore, after fertilization the Ph. pubescens stands culm weight dropped but the culm diameter and stands density increased over time indicating that opti- mal fertilization could increase stands level bio-productivity. [Ch, 5 fig. 3 tab. 16 ref.]