Effect of the addition of nitrogen and phosphorus in the structure of a seminatural grassland of early secondary succession stage

Nitrogen (N), and phosphorus (P) are the soil resources that most commonly affect primary productivity and as such determine the structure of plant communities in terrestrial ecosystems. The aim of this study was to examine the effects of these two resources on the primary productivity and structure (composition of functional groups – grasses, legumes and forbs) in a seminatural grassland of early secondary succession stage. The results showed that N was a limiting resource, and its increased availability tended to maximize the primary productivity of the grassland and favor the functional group of grasses. On the other hand legumes, having the ability to fix atmospheric N2, exhibited an increased competitiveness when N was limiting, particularly following water and P additions.