苔藓-蓝藻共生体关系与固氮能力研究进展

Bryophyte-cyanobacteria symbioses and their nitrogen fixation capacity——A review

苔藓-蓝藻共生体(BCS)能固氮,是养分贫瘠地区森林氮输入的不可忽视的来源。BCS关系与固氮能力研究为科学认识生态系统氮输入与氮循环过程和机理提供了新的视角和有效途径,具有重要的理论价值。然而,BCS关系、固氮作用与机理的研究迄今未受到足够关注,报道较少,认识仍然是零星而片段化的。基于系统查阅的相关文献,该文综述了BCS的种类组成与共生关系类型、固氮能力及所固定氮的去向及其影响因素和作用机理,指出了存在的问题及需要深入关注和亟待突破的4个研究方向。

Bryophyte-cyanobacteria symbiosis（BCS） is a key source of nitrogen input into ecosystems in nutrient-poor regions. Investigating BCS relationships and the nitrogen fixation capacity can be a new pathway and window to explore the process and mechanism of nitrogen input and nitrogen cycling. However, BCS relationships and nitrogen fixation/cycling processes and mechanisms remain poorly studied, and most of these studies have only focused on the boreal forest, with no report from Chinese forests. Based on systematic literature search and analysis, this review provides a summary on BCS relationships, the nitrogen fixation capability of BCS, the fate of fixed nitrogen, as well as the environmental factors and driving mechanisms of BCS. Firstly, we synthesized different types of BCS, the mechanisms by which the fixed nitrogen is transferred to and used by other plants within the forest, the rate of fixed nitrogen, the factors influencing the rate of nitrogen fixation. Moreover we point out the existing problems that need to pay close attention to and at least four research directions need to break through. Furthermore, the theoretical basis of BCS is provided for further research, promote and deepen the cognition of BCS and nitrogen-fixing research.