Animal-plant-soil nutrient relationships on Marion Island (Subantarctic).

Manuring by the many seals and seabirds forms the major source of N and P to the Marion Island terrestrial ecosystem and plants at manured sites exhibit enhanced vitality and increased N and P contents in their leaf tissue and saps. A similar effect results from small applications of NPK fertilizer. Non-manured soils possess very low levels of available N but substantial quantities of organic N.