Contrasting root foraging strategies of two subtropical coniferous forests under an increased diversity of understory species
Contrasting root foraging strategies of two subtropical coniferous forests under an increased diversity of understory species
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DOI：
10.1007/s11104-019-03936-y
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发表时间：
2019-03
期刊：
影响因子：
4.9
通讯作者：
Han Yan;L. Kou;Huimin Wang;Xiaoli Fu;Xiaoqin Dai;Shenggong Li
中科院分区：
文献类型：
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作者：
Han Yan;L. Kou;Huimin Wang;Xiaoli Fu;Xiaoqin Dai;Shenggong Li
背景与目的植物地上部生长和性状的研究表明，植物具有更快的生长速度和更大的叶片性状可塑性，以适应不断变化的环境。然而，我们的知识，地下生长和性状的反应和相关的根觅食策略，在竞争仍然limited.MethodsUsing林下物种添加实验，我们调查了功能为基础的根的反应，（吸收细根[AFR]与运输细根[TFR]）生长、菌根关联和基于顺序的根性状（形态、结构和化学性状）（本地种）和湿地松结果高林下物种多样性增加了AFR的生物量，但两种植物的总根数和总细根数（AFR + TFR）均不相同。较高的多样性增加了芦苇AFR和TFR的生物量比例。湿地，表明在植物碳投资的两个功能根模块之间的权衡为P。湿地植物较高的多样性增加了P. massoniana，但不影响P.湿地植物物种多样性的增加降低了P. massoniana，而P.湿地植物物种多样性的增加改变了分支相关的性状（增加分支比和强度），但不影响形态（直径，比根长，根组织密度）或化学性状的根订单的任一species.ConclusionsOur研究结果表明，P。elliottii采用双重根系觅食策略（生长和菌根策略），并在AFR和TFR构建之间进行成本效益权衡。相比之下，马尾松只在竞争条件下促进根系生长。这些结果有助于更好地理解植物的根系觅食策略和外来物种在新环境中的快速适应。
Background and aimsStudies on the aboveground growth and traits of plants suggest that plants exhibit faster growth with greater plasticity in leaf traits to adapt to changing environments. However, our knowledge of belowground growth and trait responses and associated root foraging strategies, under competition remains limited.MethodsUsing an understory species-addition experiment, we investigated the responses of function-based root (absorptive fine roots [AFRs] vs. transport fine roots [TFRs]) growth, mycorrhizal association, and order-based root traits (morphological, architectural, and chemical traits) ofPinus massoniana(native species) andPinus elliottii(exotic species), which are the dominant coniferous tree species in subtropical China.ResultsHigher understory-species diversity increased the biomass of AFRs, but not TFRs and total fine roots (AFRs plus TFRs) of both species. Higher diversity increased the biomass ratio of the AFRs and TFRs ofP. elliottii, indicating a tradeoff in plant carbon investment between the two functional root modules forP. elliottii. Higher diversity increased the total root length ofP. massoniana, but did not affect that ofP. elliottii. Increased species diversity decreased the ectomycorrhizal colonization rate ofP. massoniana, but increased that ofP. elliottii. Increased species diversity altered the branching-related traits (increased branching ratio and intensity), but did not affect the morphological (diameter, specific root length, and root tissue density) or chemical traits across the root orders of either species.ConclusionsOur findings indicate thatP. elliottiiemployed dual root foraging strategies (growth and mycorrhizal strategies) and had a cost-benefit tradeoff between AFR and TFR construction. In comparison,P. massonianaonly accelerated root growth under competition. These results facilitate a better understanding of the root foraging strategies of plants and the rapid adaptation of exotic species in novel environments.