As rising sea levels alter coastal ecosystems, there is a pressing need to examine the effects of saltwater intrusion on coastal communities. Using 16S Illumina profiling, we characterized the communities of baldcypress tree (Taxodium distichum) root endosphere and rhizosphere soil bacteria. Our study utilized established sites along salinity and flooding gradients in the United States of Georgia, Louisiana, and South Carolina. We hypothesized that environmental variables, namely salinity and water level, as well as distance between sites would be correlated with baldcypress-associated rhizosphere and root endosphere bacterial communities. We found that geographic distance correlated with rhizosphere but not root endosphere bacterial communities, suggesting that the trees may have stabilized their endosphere communities via recruitment of a more specific suite of taxa from the surrounding soil. Mean water level, mean salinity, and the volume of woody debris were associated with both endosphere and rhizosphere bacterial communities in baldcypress trees. The density of host trees was also associated with endosphere community composition. Our study is the first to use 16S Illumina sequencing to characterize bacterial communities in baldcypress trees— a key restoration species in coastal swamp ecosystems under threat from rising sea levels.

随着海平面上升改变沿海生态系统，迫切需要研究盐水入侵对沿海社区的影响。使用16S Illumina轮廓分析，我们对秃柏树（Taxodium distichum）根内球和根际土壤细菌。我们的研究利用了佐治亚州，路易斯安那州和南卡罗来纳州沿盐度和洪水梯度建立的站点。我们假设环境变量，即盐度和水位，以及位点之间的距离将与秃头草相关的根际和根内球菌的细菌群落相关。我们发现地理距离与根际相关，但与根内层细菌群落无关，这表明树木可能通过从周围土壤中募集一套更具体的分类单元来稳定了其内层群落。秃柏的平均水位，平均盐度和木质碎片的体积与球内和根际细菌群落有关。寄主树的密度也与内球群落组成有关。我们的研究是首次使用16S Illumina测序来表征秃头树中的细菌群落，秃头树是受到海平面上升威胁的沿海沼泽生态系统中的关键恢复物种。