Changes in Microbial Biomass, Activity, Functional Diversity, and Enzyme Activity in Tree Peony (Paeonia suffruticosa) Garden Soils

Abstract

To understand the effects of tree peony (Paeonia suffruticosa) on soil microbiological and biochemical properties, soil samples were collected from tree peony growing sites with 3 growth years and four tree peony cultivars as well as from an adjacent wasteland in a tree peony garden at Luoyang, Henan Province of China. With the development of the tree peony garden ecosystem, soil microbial biomass carbon (Cmic), basal respiration (Rmic), Cmic as a percent of soil organic C (Cmic/Corg), and enzyme activities first increased and then decreased. For the tree peony cultivars Yao Huang and Dou Lu, Cmic, Rmic, Cmic/Corg, catalase, invertase, cellulose, proteinase, and phosphatase decreased after 5 years of growth, whereas urease decreased after 12 years. For the cultivars Er Qiao and Shou An Hong, catalase, proteinase, and phosphatase decreased after 5 years, whereas Cmic, Rmic, Cmic/Corg, invertase, cellulose, and urease decreased after 12 years. Biolog analysis indicated that the average well color development and microbial functional diversity were significantly greater at the 5-year sites than in the wasteland but decreased significantly as growth continued. The growth duration of tree peony had a greater effect on soil microbial communities than did tree peony cultivar.