| 摘要: |
| 为探究油茶林郁闭度与坡位对多花黄精 Polygonatum cyrtonema 生长及 0 ~ 20 cm 土壤层理化性
质的调控机制, 以 8 a 生油茶林下栽培的 3 a 生多花黄精为研究对象, 试验地坡度为 15°, 共设置了 4 个郁
闭度梯度, 分别为 Y0 [0~0. 2)、 Y1 [0. 2 ~ 0. 4)、 Y2 [0. 4 ~ 0. 7)、 Y3 [0. 7 ~ 1. 0]; 3 个坡位分别为上
坡 (P1)、 中坡 (P2) 和下坡 (P3); 采用双因素方差分析、 Pearson 相关性与隶属函数法综合评价生境
适宜性。 结果表明, 郁闭度为 [0. 2 ~ 0. 4) 显著提升多花黄精株高和块茎鲜质量 (P<0. 05), 较 [0 ~
0. 2) 郁闭度增幅达 20. 85%和 25. 83%。 中坡位因水热均衡与养分截留效应, 其土壤全钾与速效钾含量显
著高于其他坡位 (P<0. 05), 较下坡位地径增长 27. 17%、 块茎厚增长 16. 04%, 表现最优。 上坡位土壤瘠
薄限制多花黄精地径发育。 郁闭度与坡位对多花黄精生长和土壤理化指标的主效应显著 (P<0. 01), 但交
互作用不显著, 表明二者调控路径相对独立。 隶属函数评价显示, [0. 2 ~ 0. 4) 郁闭度和中坡位组合隶属
函数平均值为 0. 914, 是油茶林下多花黄精最优生境, 其水解氮、 含水量及块茎鲜质量协同达峰值。 [0 ~
0. 2) 郁闭度和上坡位组合隶属函数平均值为 0. 082, 因高温蒸发与氮匮乏表现最差。 研究结果阐明了
“郁闭度主控光氮资源, 坡位主导钾素分布” 的独立调控机制。 |
| 关键词: 油茶林 多花黄精 郁闭度 坡位 生长性状 土壤理化性质 |
| DOI： |
| 分类号: |
| 基金项目:湖南省科技创新计划 (2024RC8144), 衡阳市科技计划 (202424037425)。 |
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| Effects of Canopy Density and Slope Position in Camellia Oleifera Forests on Growth and Soil Properties of Polygonatum Cyrtonema |
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Yangyihan1, MENG Yaping2, LI Wei2, LI Yan3, JIANG Rundi1, LIU Xiaowen4, CHEN Li2
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1.Yunnan Vocational and Technical College of Agriculture;2.Hengyang Academy of Agricultural Sciences;3.Hunan Linbo Agriculture Co., Ltd.;4.Hunan University of Science and Technology
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| Abstract: |
| This study investigated the regulatory mechanisms of canopy density and slope position in Camel-lia oleifera forests on the growth of Polygonatum cyrtonema and the physicochemical properties of the 0-20 cm
soil layer, using 3-year-old P. cyrtonema cultivated under 8-year-old C. oleifera stands on a 15° slope. The
experiment included four canopy density gradients, Y0 [0-0. 2), Y1 [0. 2-0. 4), Y2 [0. 4-0. 7), and Y3
[0. 7-1. 0], and three slope positions, upper slope (P1), middle slope (P2), and lower slope (P3). Habitat suitability was comprehensively evaluated using two -way ANOVA, Pearson correlation, and membership
function analysis. The results showed that a canopy density of [0. 2-0. 4) significantly increased plant height
and tuber fresh weight of P. cyrtonema (P<0. 05), and the increases were 20. 85% and 25. 83%, respectively,
compared to the [0-0. 2) canopy density. The middle slope position (P2) had significantly higher soil total potassium and available potassium content than other slope positions (P<0. 05) because of balanced hydrothermal
conditions and nutrient retention effect. Its basal diameter and tuber thickness increased by 27. 17% and
16. 04%, respectively, compared to the lower slope, showing the best performance. In contrast, poor soil fertility at the upper slope limited basal diameter development. Canopy density and slope position had significant
main effects on the growth of P. cyrtonema and soil physicochemical indicators (P<0. 01), but their interaction
was not significant, indicating relatively independent regulatory pathways. Membership function evaluation revealed that the combination of [0. 2-0. 4) canopy density and middle slope position achieved the highest average
score of 0. 914, representing the optimal habitat for P. cyrtonema under C. oleifera forests, where hydrolyzed
nitrogen, soil moisture content, and tuber fresh weight simultaneously reached their peak values. In contrast,
the combination of [0-0. 2) canopy density and upper slope position scored the lowest (0. 082), performing
poorest due to high-temperature-induced water evaporation and nitrogen deficiency. The results elucidate an independent regulatory mechanism whereby canopy density primarily controls light and nitrogen resources, while
slope position dominates potassium distribution. |
| Key words: Camellia oleifera forests Polygonatum cyrtonema canopy density slope position growth traits soil physicochemical properties |
