林火干扰对北方针叶林林下植被的影响

A review of effects of fire disturbance on understory vegetation in boreal coniferous forest

林下植被在北方针叶林植被群落中的物种多样性最高,且具有较高的生物量周转率和地上部分净初级生产力,对北方针叶林生态系统功能起着重要作用。火干扰是决定北方针叶林林下植被结构与功能的一个重要景观过程。该文综述了火干扰是如何通过与地形、火前林冠组成的交互作用而影响环境资源和林下植被的。最近的研究表明:林下植被能够影响火后树木更新苗的定植、重建速率及森林演替轨迹;林下植被还会通过影响元素的生物地球化学过程(凋落物降解和养分循环)影响林下环境资源的数量与异质性。因此,研究火后初期北方针叶林林下植被的动态变化,对于物种多样性保护和森林管理具有重要意义。

Understory vegetation in boreal forests is the most diverse and least understood component of boreal plant communities. In addition, the aboveground net primary productivity of understory vegetation is almost comparable to that of the trees, and the biomass turns over more rapidly than does that of the trees. Fire disturbance is an important landscape process, driving understory structure and function in boreal forests. We review recent research about how fire, interacting with topography and overstory canopy, affects environmental resources （e.g., light and soil nutrients） and understory vegetation. Recent studies have demonstrated that understory vegetation in boreal forests can also influence post-fire tree seedling regeneration, rate of recovery and successional pathways. It can also affect the quantity and heterogeneity of environmental resources by influencing biogeochemical processes such as decomposition and nutrient flow. Understanding understory vegetation dynamics after fire, especially during early succession, is very important for biodiversity conservation and management of boreal forest.