Black mangrove (Avicennia germinans) stands in south Texas grow in association with other autotrophic organisms including herbaceous halophytes and cyanobacterial mats. Despite the relevant ecosystem services provided by this coastal plant community, limited information exists on its functioning, in particular as it pertains to nutrient dynamics, namely nitrogen (N). Nitrogen stable isotopes were used to assess potential N sources for plant growth in this community. Plant tissue (leaves), cyanobacteria, and sediment were sampled once every season for one year. Total N in A. germinans (2.6 %) and associated saltwort (Batis maritima) (2.1 %) was higher than in cyanobacteria (0.6 %), and sediment (0.1 %). Isotopic signatures (δ¹⁵N) in A. germinans (5.85 ‰) and B. maritima (4.75 ‰) were more similar to sediment (5.21 ‰) than to cyanobacteria (1.98 ‰), suggesting mangroves and saltwort obtain N mostly from the sediment; no evidence of N transfer from cyanobacteria was found.

黑红树林（Avicennia Germinans）位于得克萨斯州南部，与其他自养生物（包括草本盐生植物和蓝藻垫）结合生长。尽管该沿海植物群落提供了相关的生态系统服务，但是关于其功能的信息有限，尤其是与养分动力学即氮（N）有关的信息。氮稳定同位素用于评估该社区植物生长的潜在氮源。每一年对植物组织（叶片），蓝细菌和沉积物进行采样，为期一年。产气链球菌（2.6％）和伴生的盐蒿（Batis maritima）（2.1％）的总氮高于蓝细菌（0.6％）和沉积物（0.1％）。同位素特征（δ ¹⁵ N）中A.菌种（5.85‰）和B. maritima（4.75‰）与沉积物（5.21‰）比蓝细菌（1.98‰）更相似，表明红树林和盐麦芽汁主要从沉积物中获取N。没有发现从蓝细菌转移氮的证据。