Effects of elevated CO2 and phosphorus addition on productivity and community composition of intact monoliths from calcareous grassland.

摘要: We investigated the effects of elevated CO2 (600 μl l−1 vs 350 l−1) and phosphorus supply (1 g P m−2 year−1 unfertilized) on intact monoliths from species-rich calcareous grassland in a greenhouse. Aboveground community dry mass remained almost unaffected by first year (+6%, n.s.), but was significantly stimulated enrichment two (+26%, 0.05). Belowground biomass stubble after seasons were not different when added. The small initial increase aboveground under is explained fact that some species, particular Carex flacca, responded very positively right beginning, while others, especially dominant Bromus erectus, negatively to enrichment. Shifts composition towards more responsive species explain much larger response second year. These shifts, i.e., decline xerophytic elements (B. erectus) an mesophytic grasses legumes occurred independently treatments all accelerated CO2. difference average production at compared ambient higher supplied (at level enhanced 20% 33% added, graminoids 17% 27%, 4% 60%, C. flacca 120% 298% two). Based observations this similar studies, we suggest interactions between concentration, presence, nutrient availability will govern responses