Walker Janet B, Rinehart Shelby, Greenberg-Pines Gabriel, White Wendi K, DeSantiago Ric, Lipson David A, Long Jeremy D
Department of Biology San Diego State University San Diego California USA.
Coastal and Marine Institute San Diego State University San Diego California USA.
Ecol Evol. 2022 Mar 22;12(3):e8722. doi: 10.1002/ece3.8722. eCollection 2022 Mar.
Interspecific interactions between plants influence plant phenotype, distribution, abundance, and community structure. Each of these can, in turn, impact sediment biogeochemistry. Although the population and community level impacts of these interactions have been extensively studied, less is known about their effect on sediment biogeochemistry. This is surprising given that many plants are categorized as foundation species that exert strong control on community structure. In southern California salt marshes, we used clipping experiments to manipulate aboveground neighbor presence to study interactions between two dominant plants, Pacific cordgrass () and perennial pickleweed (). We also measured how changes in cordgrass stem density influenced sediment biogeochemistry. Pickleweed suppressed cordgrass stem density but had no effect on aboveground biomass. For every cordgrass stem lost per square meter, porewater ammonium increased 0.3-1.0 µM. Thus, aboveground competition with pickleweed weakened the effects of cordgrass on sediment biogeochemistry. Predictions about plant-soil feedbacks, especially under future climate scenarios, will be improved when plant-plant interactions are considered, particularly those containing dominant and foundation species.
植物之间的种间相互作用会影响植物的表型、分布、丰度和群落结构。反过来，这些因素中的每一个都可能影响沉积物生物地球化学。尽管这些相互作用对种群和群落水平的影响已得到广泛研究，但它们对沉积物生物地球化学的影响却知之甚少。鉴于许多植物被归类为对群落结构具有强大控制作用的基础物种，这一现象令人惊讶。在南加州盐沼，我们通过修剪实验来控制地上邻居的存在，以研究两种优势植物太平洋米草（）和多年生滨藜（）之间的相互作用。我们还测量了米草茎密度的变化如何影响沉积物生物地球化学。滨藜抑制了米草的茎密度，但对地上生物量没有影响。每平方米每损失一根米草茎，孔隙水中的铵就会增加0.3 - 1.0微摩尔。因此，与滨藜的地上竞争削弱了米草对沉积物生物地球化学的影响。当考虑植物 - 植物相互作用，特别是那些包含优势种和基础物种的相互作用时，对植物 - 土壤反馈的预测，尤其是在未来气候情景下，将会得到改善。
