In a glass house experiment, we investigated the effect of both the frequency of water pulses and the total amount of water supplied on individual performance in the absence and presence of neighbors. We used monocultures and all combinations of pairs of seedlings of three species of perennial grasses, characteristic of different points along a soil moisture gradient within a semi-arid grassland in New Mexico, USA. In the absence of neighbors, higher total water or more frequent (but smaller) pulses significantly increased growth of all three species. The species with the fastest intrinsic growth rate, and from the most productive habitat, exhibited the largest increase in absolute and relative growth in response to higher total water [...]
