摘要
[目的]探究海南中部丘陵区人工林林下植被和土壤养分的特征,分析影响该地区人工林林下植被多样性的主要土壤养分因子,为海南中部丘陵区和海南热带雨林国家公园人工林生态系统的生物多样性保护和科学经营提供理论依据.[方法]以海南省枫木实验林场广泛分布的3种人工林(马占相思林、桉树林、橡胶林)为研究对象,基于林下植物调查和土壤养分测定,对比分析不同林分间林下植被物种组成、植物物种多样性及土壤养分含量的差异;通过RDA排序揭示影响林下植被物种多样性的主要土壤养分因子.[结果]3种人工林林下植被茂盛,桉树林林下植物种数(68种)最多,其次是马占相思林(60种),橡胶林(58种)最少.各人工林灌木层的Margalef指数和Shannon-Wiener指数以马占相思林最高,且显著大于桉树林和橡胶林(P<0.05,下同),而Shimpson指数和Pielou指数在不同林分间无显著差异(P>0.05);桉树林和橡胶林间草本层Margalef指数、Shannon-Wiener指数、Shimpson指数和Pielou指数均无显著差异,均显著高于马占相思林.3种人工林土壤pH 4.58～4.75,均呈酸性;3种林分间土壤养分含量除全氮和速效磷,其余均存在显著差异,桉树林的土壤有机质、全磷、速效钾和速效氮含量最高,马占相思林的土壤全钾含量最高,橡胶林的土壤全氮和有效磷含量最高.RDA分析结果显示,有机质和全氮含量对植物物种多样性变化的解释度分别为56.2%和22.2%,且均达极显著水平(P<0.01),是影响该区域人工林林下植物物种多样性主要土壤因子.[结论]海南中部丘陵区人工林林下植物种类丰富,3种人工林林下植物组成、植物物种多样性和土壤养分存在显著差异,有机质和全氮是影响该地区人工林林下植物多样性的主要土壤养分驱动因子,在经营和管理中应注重有机肥和氮肥的施加.
Abstract
[Objective]To investigate the characteristics of understorey vegetation and soil nutrients in plantation for-ests in the hilly areas of central Hainan,and to reveal the main soil nutrient factors affecting the diversity of understorey vegetation in plantation forests in this area,with a view to providing theoretical basis for biodiversity conservation and sci-entific management of plantation forest ecosystems in the hilly areas of central Hainan and Hainan Tropical Rainforest Na-tional Park.[Method]Three types of plantation forests(Acacia mangium forest,Eucalyptus robusta forest and Hevea brasiliensis forest)widely distributed in Fengmu Experimental Forestry Farm of Hainan were used as the research objects.Based on the understorey plant surveys and soil nutrient measurements,compared and analyzed the differences in the composition of the understorey vegetation species,the diversity of the plant species,and the content of the soil nutrients among the different forest stands,and revealed the main soil nutrient factors that affected the diversity of the understorey vegetation species through RDA ranking.[Result]The understorey vegetation of the three plantation forests was lush,with E.robusta forest having the highest number of understorey plant species(68),followed by A.mangium forest(60),and H.brasiliensis forest had the lowest number of understorey plant species(58).The Margalef index and Shannon-Wiener index of the shrub layer of each plantation forest were the highest in the A.mangium forest,and were significantly larger than those in the E.robusta forest and H.brasiliensis forest(P<0.05,the same below),whereas there was no sig-nificant difference in the Shimpson index and the Pielou index among different forest stands(P>0.05),and Margalef in-dex,Shannon-Wiener index,Shimpson index and Pielou index were not significantly different between E.robusta forest and H.brasiliensis forest herb layer,and were significantly higher than that of A.mangium forest.The soil pH of the three plantation forests ranged from 4.58 to 4.75,all of which were acidic.There were significant differences in soil nutri-ent contents among the three forests except for total nitrogen and available phosphorus,with E.robusta forest having the highest content of organic matter,total phosphorus,available potassium,and available nitrogen,A.mangium forest hav-ing the highest content of total potassium,and H.brasiliensis forest having the highest content of total nitrogen and effec-tive phosphorus.The results of RDA analysis showed that organic matter and total nitrogen content explained 56.2%and 22.2%of the variation in plant species diversity respectively,and both of them reached the extremely significant level(P<0.01),which were the main soil factors affecting plant species diversity in the understorey of plantation forests in the area.[Conclusion]The plantation forest understorey in the central hilly area of Hainan is rich in plant species,and there are significant differences in plant composition,plant species diversity and soil nutrients among the three plantation for-ests.Organic matter and total nitrogen are the main soil nutrient drivers affecting the plant diversity of the plantation forest understorey in this area,and organic and nitrogen fertilizers should be applied in the operation and management of planta-tion forest understorey in this area.
基金项目
海南省科研院所技术创新专项技术开发项目(jscx202022)
海南省科研院所技术创新专项基础科研项目(JCYJ-2022-06)
国家科技期刊平台
NSTL
万方数据