Testing the effects of species interactions and water limitation on tree seedling biomass allocation and physiology
Testing the effects of species interactions and water limitation on tree seedling biomass allocation and physiology
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DOI：
10.1093/treephys/tpab005
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发表时间：
2021-02-08
期刊：
影响因子：
4
通讯作者：
Anderegg, William R. L.
中科院分区：
文献类型：
--
作者：
Kerr, Kelly L.;Zenes, Nicole;Anderegg, William R. L.
物种间的相互作用介导树响应水分限制，因为竞争和/或促进改变植物的生理和生长。然而，由于很难将植物-植物相互作用和水分限制的影响与其他环境因素隔离开来，因此对干旱下共存植物的树木生理和生长机制知之甚少。以白杨为重点树种，在人工控制的生长室内研究了种间相互作用和水分限制对颤白杨、狭叶棉白杨和黄松幼苗生理和生长的影响。将幼苗单独或与异源或异源特异性幼苗一起在盆中生长，并进行限水处理。在处理前、处理中和处理后，测定了生长、水分状况和生理指标。在良好的浇水条件下，另一个幼苗的存在影响所有物种的生长或生物量分配，但不影响我们测量的生理性状。在水分限制下，竞争幼苗的存在对所有物种的幼苗生长和生理特性的影响都很小。在整个研究过程中，幼苗反应的幅度和方向是复杂的，往往是物种特异性的。我们的研究是测试物种之间的相互作用如何改变水分充足和水分有限时期的生理反应和生长的重要一步。
Species interactions mediate tree responses to water limitation because competition and/or facilitation alter plant physiology and growth. However, because it is difficult to isolate the effects of plant-plant interactions and water limitation from other environmental factors, the mechanisms underlying tree physiology and growth in coexisting plants under drought are poorly understood. We investigated how species interactions and water limitation impact the physiology and growth of trembling aspen (Populus tremuloides), narrowleaf cottonwood (Populus angustifolia) and ponderosa pine (Pinus ponderosa) seedlings in a controlled environment growth chamber, using aspen as a focal species. Seedlings were grown in pots alone or with a con- or hetero-specific seedling, and were subjected to a water limitation treatment. Growth, water status and physiological traits were measured before, during and after the treatment. Under well-watered conditions, the presence of another seedling affected growth or biomass allocation in all species, but did not impact the physiological traits we measured. Under water limitation, the presence of a competing seedling had a marginal impact on seedling growth and physiological traits in all species. Throughout the study, the magnitude and direction of seedling responses were complex and often species-specific. Our study serves as an important step toward testing how species' interactions modify physiological responses and growth in well-watered and water-limited periods.