Changes in grassland species diversity, biomass allocation and phenology with warming in a trasplanting experiment.

SEBASTIÁ, M.T., R. BLANCO, J. CONNOLLY, N.N. CHIUV & FRANCESCHINI, M.C.

Amsterdam

Congreso; Congress of Global Change and Terrestrial Ecosystems; 2001

--

We conducted a climate change experiment by transplanting monoliths of subalpine grasslands from the Pyrenees to low altitudes, where temperature was higher, water availability was lower, and there was an increase in CO2, as predicted by climate change models for the area. Total aboveground biomass increased under warming. However, root biomass by mid growing season was not significantly different between treatments, and the proportion of biomass allocated to roots was higher in the control plots. Differences in vegetation at different dates within the same treatment were bigger than differences between treatments for a given date. However, rare species showed a tendency to disappear in the warming treatment by the end of the experiment, and the abundant species changed their biomass ranking with warming. Flowering and fruiting were more intense, and more species flowered in the upland than in the lowland, particularly forbs. Graminoids showed low flowering frequency in both cases.