Soil microbial functional diversity under intensively managed bamboo plantations in southern China

Background, aim, and scope Bamboo (Phyllostachy pubescens Mazel ex Lehaie), a unique fast-growing tree species, is an important forest resource in southern China. Because of its high economic value and short rotation period, intensive management practices such as fertilization, weeding, and deep tilling are extensively utilized. These practices significantly increase the production of mature timber and young shoots. In this paper, bamboo stands under intensive management with short-term (STIP) and long-term (LTIP) practices were compared with those managed conventionally (CON) to study the effects of intensive management practices on soil biological properties. Materials and methods We measured the soil microbial biomass carbon (MBC), basal respiration carbon (BRC), and the specific ability of soil microbiota to consume a range of carbon (C) substrates, measured by Biolog ECO MicroPlate. Results Intensive management practice significantly decreased (P < 0.05) soil MBC (in the order of CON > STIP > LTIP), but increased soil BRC (in the order of STIP [almost equal to] LTIP > CON). Under intensive management practices, soil microbial activity, and diversity of C sources utilized by microbial communities decreased (P < 0.05), as characterized by average well color development (AWCD). Shannon and McIntosh indexes tended to decline with intensive management practices. Intensive management practice also caused much lower (P < 0.05) utilization of 2-hydroxy benzoic acid and a-cyclodextrin. Discussion Soil biological properties were proved to be sensitive indicators of soil quality in response to the intensive management practices, with decreases in soil MBC, microbial activity, and diversity of C sources utilized by microbial communities under the continuing intensive management practices in bamboo stands. This indicates that the intensive management practices had resulted in the negative effect on the soil microbial activities. Conclusions Intensive management practices generally had a negative influence on the soil biological properties. This would have important implications for the sustainable management of bamboo production systems in southern China. Recommendations and perspectives To minimize the detrimental effect on soil microbial communities, an improved intensive management practice with reducing amounts of mineral fertilizer and increasing organic fertilizer applications are recommended annually so that both high bamboo yield and soil quality can be sustained over a long period.