Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China.
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China.
Sci Total Environ. 2024 May 10;924:171517. doi: 10.1016/j.scitotenv.2024.171517. Epub 2024 Mar 8.
Shrubs have developed various mechanisms for soil phosphorus utilization. Shrub encroachment caused by climate warming alters organic phosphorus mineralization capability by promoting available phosphorus absorption and mediating root exudates. However, few studies have explored how warming regulates the effects of dominant shrubs on soil organic phosphorus mineralization capability. We provide insights into warming, dominant shrub removal, and their interactive effects on the soil organic phosphorus mineralization potential in the Qinghai-Tibetan Plateau. Real-time polymerase chain reaction was used to quantify the soil microbial phosphatase genes (phoC and phoD), which can characterize the soil organic phosphate mineralization potential. We found that warming had no significant effect on the soil organic phosphate-mineralized components (total phosphate, organic phosphate, and available phosphate), genes (phoC and phoD), or enzymes (acid and alkaline phosphatases). Shrub removal negatively influenced the organic phosphate-mineralized components and genes. It significantly decreased soil organic phosphate mineralization gene copy numbers only under warming conditions. Warming increased fungal richness and buffered the effects of shrub removal on bacterial richness and gene copy numbers. However, the change in the microbial community was not the main factor affecting organic phosphate mineralization. We found only phoC copy number had significant correlation to AP. Structural equation modelling revealed that shrub removal and the interaction between warming and shrub removal had a negative direct effect on phoC copy numbers. We concluded that warming increases the negative effect of shrub removal on phosphorus mineralization potential, providing a theoretical basis for shrub encroachment on soil phosphate mineralization under warming conditions.
灌木已经发展出了各种利用土壤磷的机制。气候变暖导致的灌木入侵通过促进有效磷的吸收和介导根分泌物来改变有机磷矿化能力。然而，很少有研究探讨变暖如何调节优势灌木对土壤有机磷矿化能力的影响。我们深入了解了变暖、优势灌木去除及其对青藏高原土壤有机磷矿化潜力的交互作用。实时聚合酶链反应被用来定量土壤微生物磷酸酶基因（phoC 和 phoD），这些基因可以表征土壤有机磷酸盐矿化潜力。我们发现变暖对土壤有机磷酸盐矿化成分（总磷酸盐、有机磷酸盐和有效磷酸盐）、基因（phoC 和 phoD）或酶（酸性和碱性磷酸酶）没有显著影响。灌木去除对有机磷酸盐矿化成分和基因有负面影响。只有在变暖条件下，它才会显著降低土壤有机磷酸盐矿化基因的拷贝数。变暖增加了真菌的丰富度，并缓冲了灌木去除对细菌丰富度和基因拷贝数的影响。然而，微生物群落的变化不是影响有机磷酸盐矿化的主要因素。我们只发现 phoC 拷贝数与 AP 有显著相关性。结构方程模型显示，灌木去除以及变暖与灌木去除之间的相互作用对 phoC 拷贝数有负向直接影响。我们得出结论，变暖增加了灌木去除对磷矿化潜力的负面影响，为变暖条件下灌木入侵对土壤磷酸盐矿化的影响提供了理论依据。
