几种沙生灌木生物量及其在不同器官分配与土壤理化特征相关性

Correlation between Biomass and Its Allocation in Different Organs and Soil Physical and Chemical Characteristics in Several Sandy Shrubs

灌木群落的生物量及其在不同器官分配与土壤理化特征之间关系复杂。以毛乌素沙地柠条锦鸡儿(Caragana korshinskii)、油蒿(Artemisia ordosica)、杨柴(Hedysarum fruticosum)灌木群落为研究对象,分析了不同灌木的生物量分配与土壤理化特征的相关性。结果表明:供试的3种灌木整株生物量与各器官生物量均为:柠条锦鸡儿>油蒿>杨柴,且达到了显著性差异(P<0.05)。3种灌木各器官生物量及分配比例为:茎>根>叶。其中,柠条锦鸡儿的生物量在茎、根、叶的分配比例分别为62%、25%、13%;油蒿的分配比例分别为53%、30%、17%;杨柴分别是55%、35%、10%。3种灌木群落土壤有机质含量均表现为随土层加深而递减的垂直变化特征。相关性分析表明,3种灌木整株生物量与土壤有机质含量呈极显著正相关性(r=0.920**,P<0.01),与土壤全氮、速效氮含量呈显著正相关性,相关系数分别为r=0.762*(P<0.05)和r=0.789*(P<0.05),而与土壤全磷和速效磷含量的关系不显著。3种灌木整株生物量及其在不同器官分配特征与荒漠生境有关,它们与干旱、半干旱环境长期相互作用产生了不同的生存策略,茎的木质化程度、叶构型、根系分布情况会影响各器官的异速生长,进而影响了生物量的分配特征。在荒漠生态系统中,灌木林生产力受群落类型和土壤养分的共同制约。

Taking the shrub communities of Caragana korshinskii, A rtemisia ordosica and Hedysarum fruticosum as the research objects, this paper analyzed the correlation between their biomass allocation and soil physical and chemical characteristics. The results showed that the whole plant biomass of three shrubs significantly decreased （P 〈 0.05） in the order of Caragana korshinskii 〉 Artemisia ordosica 〉 Hedysarum fruticosum, while the biomass of different organs and their distribution ratios were stem 〉 root 〉 leaf. Thereinto, the proportion of biomass distributed to stem, root and leaf was, respectively, 62%, 25% and 13% in Caragana korshinskii, 53%, 30% and 17% in Artemisia ordosica, 55%, 35% and 10% in Hedysarum fruticosum. Besides, the content of soil organic matter in three shrub communities showed obviously decreased trend with soil depth. The correlation analysis indicated that the biomass of three shrubs had a significant positive correlation with soil organic matter content （r = 0.920＊＊, P 〈 0.01）, soil total nitrogen content （r = 0.762＊, P 〈 0.05） and soil available nitrogen content （r = 0.789＊, P 〈 0.05）. However, the correlation was not significant among the biomass of three shrubs and the contents soil total phosphorus and available phosphorus. The biomass and its allocation of the three shrubs were related to the desert habitat. Under long-term arid and semi-arid environments, they produced different survival strategies. The lignification degree of stems, leaf configuration and root distribution affected the allometric growth of different organs, and further the distribution characteristics of biomass. Thus, in desert ecosystems, shrub productivity was constrained by community types and soil nutrients.