Alkaline Phosphomonoesterase-Harboring Microorganisms Mediate Soil Phosphorus Transformation With Stand Age in Chinese Pinus massoniana Plantations

Abstract

<i>phoD</i>-harboring microorganisms facilitate mineralization of organic phosphorus (P), while their role in the regulation of soil P turnover under P-limited conditions in <i>Pinus massoniana</i> plantations is poorly understood. The aim of the present study was to investigate the effects of stand age and season on soil P fractions and <i>phoD</i>-harboring microorganism communities in a chronosequence of Chinese <i>P. massoniana</i> plantations including 3, 19, and 58 years. The soil P fractions (i.e., CaCl₂-P, citrate-P, enzyme-P, and HCl-P) varied seasonally, with the higher values observed in the rainy season. The concentrations of the fractions were higher in old plantation (OP) soils and lower in young planation (YP) soils in both seasons. The OTU abundances were negatively correlated with total available P concentration, while were positively correlated with alkaline phosphomonoesterase (ALP) activity at 0-10 cm soil depth. The results indicate that <i>phoD</i>-harboring microorganisms have great potential to mineralize organic P under P-poor conditions and highlights those microorganisms are indicators of P bioavailability in <i>P. massoniana</i> plantations.