摘要
研究不同密度柚木人工林对林下植被及土壤理化性质的影响,为柚木人工林营建与可持续经营提供理论依据。以广东揭阳14~16年生不同林分密度(650、900、1 050、1 200和1 450株·hm^(-2))柚木人工林为研究对象,通过样方调查植被的种名、株数、高度及盖度等,并采集0~20和20~40 cm土样进行理化性质分析,对林下植被物种多样性指数及其土壤理化性质进行主成分分析评价,来评价不同林分密度下柚木人工林的立地质量。结果表明:随着林分密度增加,柚木人工林林下植被盖度整体表现出降低趋势,草本优势物种由阳生性到中生性,逐渐向阴生性的过渡,林下植被Shannon-Wiener指数、Simpson优势度指数、丰富度指数和均匀度指数表现出先增加后减少的趋势;相同密度下,表层土土壤理化性质优于下层土,随着林分密度增大,土壤理化性质整体呈现出先改善后退化的变化过程,不同林分密度间柚木人工林土壤毛管孔隙度、非毛管孔隙度、速效K、速效P、全P、交换性酸和交换性Al等指标差异性显著(P<0.05);基于林下植被物种多样性和土壤理化性质主成分分析,不同林分密度柚木人工林物种多样性和土壤理化性质综合得分由大到小依次是:1 050株·hm^(-2)(4.82)、900株·hm^(-2)(1.58)、650株·hm^(-2)(-1.30)、1 200株·hm^(-2)(-1.81)、1 450株·hm^(-2)(-3.29)。因此,说明适宜的林分密度(1 050株·hm^(-2))有利于保持较好的林下植被物种多样性和土壤理化性质,在柚木人工林经营的过程中,可以根据实际情况合理调整林分的密度。
We studied the effect of teak ( Tectona grandis L. f) plantations with different densities on understory vegetation and soil physical-chemical properties for providing theoretical basis for establishment and sustainable management of teak plantations. We used teak plantations at age of 14 -16 with different stand densities(650, 900, 1 050, 1 200 and 1 450 tree· hm-2) in Jieyang City of Guangdong Province in the experiment. We recorded the species name, quantity, height and coverage of understory vegetation by plant quadrate, and measured soil physical-chemical properties by collecting soil samples from 0 -20 and 20 -40 cm depths, respectively. We investigated the diversity index of understory vegetation and soil physical-chemical property to evaluate site quality of teak plantation under different densities by principal component analysis. The coverage of understory vegetation was decreased with the increase of stand density. The dominant species of herbs were changed from sun species to shade-tolerant species with the increase of stand density, and the Shannon-Wiener index, Simpson index, Richness index, and Evenness index jointly showed a tendency that falls after increases first along with the raise of stand density. The physical-chemical properties in the upper layer of soil were superior to these in the deeper layer of soil at the same density. With the increase of stand density, the soil physical-chemical properties presented a change process from first improvement to degradation. The capillary porosity, non-capillary porosity, available K, available P, total P, exchangeable acid and exchangeable aluminum of soil showed significant difference among the different stand densities ( P 〈 0.05 ). By biodiversity indexes and physical-chemical properties of principal component analysis, the order of the composite score of different stand densities on species diversity and soil physical-chemical properties from high to low was: 1 050 tree · hm-2(4.82), 900 tree · hm-2(1.58), 650 tree · hm-2( - 1.30), 1 200 tree · hm-2( -1. 81) and 1 450 tree · hm-2(-3.29). By principal component analysis, the stand density( 1 050 tree · hm-2) was more favorable to maintaining better undergrowth species diversity and soil physical-chemical properties. Stand density would be adjusted reasonably according to the actual situation in the management process of teak plantation.
出处
《植物研究》
CAS
CSCD
北大核心
2017年第2期200-210,共11页
Bulletin of Botanical Research
基金
"十二五"国家科技支撑计划项目(2102BAD21B01)~~
关键词
柚木人工林
林分密度
林下植被
土壤理化性质
teak plantation
stand density
understory vegetation
soil physical-chemical properties