The distribution of male and female plants was examined in five dioecious, wind-pollinated species representing five plant families and two classes (gymnosperms and angiosperms). The arid to semiarid habitats occupied by these species in northern Utah were stratified for sampling into two categories: chronically xeric and seasonally moist. The results show that for all species, males are more abundant on xeric microsites, while females are over represented on the moister parts of each local environment. Differential distribution of the sexes along a soil moisture gradient is a strategy that maximizes seed set of females and pollen dispersal of males; it also tends to minimize intraspecific competition between the sexes.

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The photosynthetic response to temperature and moisture stress of three dominants of the west, moist, and dry meadows of the central Sierra Nevada was determined. The wet meadows are relatively cold; the dry meadows, warm and the moist meadows, intermediate. The photosynthetic response to moisture stress parallels the natural distribution with Carex exserta of the dry meadows being least sensitive, Potentilla breweri of the moist meadows intermediate, and Calamagrostis breweri of the wet meadows most sensitive. The photosynthetic response to temperature also parallels the natural distributions. Calamagrostis photosynthesis more efficiently at lower temperatures than Carex or Potentilla.