Some aspects of the nitrogen cycle in a Californian strand ecosystem

Nitrogen inputs and storage pools were quantified for 20 months on a perennial grass dominated beach-foredune area at Pt. Reyes National Seashore, CA. Atmospheric input of ammonium and nitrate by bulk precipitation (rain + dry fallout) was 1.6 kg N haɻ¹;1 yr⁻¹ and by summer fog condensation was 4.2 kg N ha⁻¹ yrɻ¹; Non-symbiotic nitrogen fixation was not detected and fixation by a nodulated legume species is negligible relative to atmospheric inputs. The total ecosystem nitrogen pool was only 390 kg ha⁻¹ , 78% of which was soil organic nitrogen, 18% was in vegetation, and 4% was inorganic soil nitrogen. Living vascular plant tissue contained 1.7% nitrogen— a value typical of crop plants on fertile soil— despite soil nitrogen content < 0.006%.