The present invention discloses a method for analyzing the sources of
nitrogen pollution in mangroves based on the stable
nitrogen isotope composition, which includes: culturing
mangrove plants in the laboratory to ensure that the initial
isotope values of each
plant are consistent; placing cages in a series of mangroves with
nitrogen concentration gradients and planting the
mangrove plants into the cages; allowing the
mangrove plants to grow in the cages for at least one month to ensure
isotope integration of the
mangrove plants; collecting mangrove
plant samples from the cages multiple times,
drying the mangrove
plant samples, and
grinding them into powders to make aluminum-
tin capsules; using a
stable isotope ratio mass spectrometer (IRMS) to analyze the δ<supgt;15< / supgt;N isotope ratio of the aluminum-
tin capsules; drawing spatial variation diagrams, temporal variation diagrams, and hotspot diagrams based on the δ<supgt;15< / supgt;N isotope ratio; and determining the sources of nitrogen
pollution according to the differences in the δ<supgt;15< / supgt;N isotope ratio of the
mangrove plants. Through the method of the present invention, accurate judgment of the sources of nitrogen
pollution in mangroves can be achieved, and it can also provide directions for environmental governance and
environmental protection.