Compensatory Photosynthetic Responses of Three African Graminoids to Different Fertilization, Watering, and Clipping Regimes

Abstract
Three C4 graminoids, Kyllinga nervosa, Themeda triandra and Hyparrhenia filipendula were grown in unbalanced factorial treatment designs of clipping height, clipping frequency [to simulate grazing pressure] watering frequency and R availability for periods equivalent to 1 growing season, after which gas exchange was measured on all plants. Clipped plants in all 3 spp. had higher photosynthetic rates, but the percentage of stimulation was least in T. triandra. Stimulation of photosynthesis may have been caused by increased stomatal opening.