植物根系养分捕获塑性与根竞争

为了更有效地从土壤中获取养分, 植物根系在长期的进化与适应中产生了一系列塑性反应, 以响应自然界中广泛存在的时空异质性。同时, 植物根系的养分吸收也要面对来自种内和种间的竞争。多种因素都会影响植物根竞争的结果, 包括养分条件、养分异质性的程度、根系塑性的表达等。竞争会改变植物根系的塑性反应, 比如影响植物根系的空间分布; 植物根系塑性程度差异也会影响竞争。已有研究发现根系具有高形态塑性和高生理塑性的植物在长期竞争过程中会占据优势。由于不同物种根系塑性的差异, 固定的对待竞争的反应模式在植物根系中可能并不存在, 其响应随竞争物种以及土壤环境因素的变化而变化。此外, 随着时间变化, 根系塑性的反应及其重要性也会随之改变。植物对竞争的反应可能与竞争个体之间的亲缘关系有关, 有研究表明亲缘关系近的植物可能倾向于减小彼此之间的竞争。根竞争对植物的生存非常重要, 但目前还没有研究综合考虑植物的各种塑性在根竞争中的作用。另外根竞争对群落结构的影响尚待深入的研究。

Review of root nutrient foraging plasticity and root competition of plants

In order to effectively absorb nutrients from naturally heterogeneous soil, plant roots employ various plastic responses to the environment heterogeneity through evolution and adaptation. In addition, plant roots also face competition from both intra- and inter-specific competitors. Factors affecting the outputs of root competition include nutrient availability, scale and degree of soil heterogeneity and ability of root plasticity. Competition adds a new dimension to plants; plant roots may alter their normal plastic responses, e.g., root competition will affect the spatial distribution of root systems. Different plastic responses of roots will in turn influence root competition per se. Previous studies have revealed that plants with high root morphological plasticity and high physiological plasticity achieved competitive advantages. Plants differ in their root nutrient foraging plasticity, and therefore may not have fixed ways of responding to competition. The uniqueness and traits of species need to be considered in comprehending the mechanisms of their plastic responses of root foraging in competition and the consequences.
The responses of roots to competitors may also be influenced by the competitors, and the competitive status of the plant may change. Closely related plants may be more likely to avoid the competition from each other. A few studies have focused on integration of root competition and root foraging plasticity, as well as the impact of root competition on the community structure. This review is intended to discuss this issue.