The purpose of this experiment is 1) to get detailed demographic information on seedling germination, survival and establishment; 2) to get detailed demographic information on adult survival; 3) to measure ecophysiological parameters like leaf water potential, stomatal conductance, photosynthesis on plants under waterstress as compared to control (normal precipitation) plots. The experiment is being conducted in fileds A and C. There are 3 treatments with 6 replicates in each of the two fields, totalling 36 4x4 m plots. Treatments are 1) a control that is watered only if necessary to maintain average moisture levels; 2) an early drought running from day 130 (May 10) through day 200 (July 19); 3) a late drought running from day 170 (June 18) through day 240 (August 28). The plots were established and the late drought was started in June 1992, the early drought was started in May 1993. The treatments were randomly assigned to the plots which are in an approximate 3x6 plots grid in field A and a 4x5 plots grid in field C. Plots were staked such that scattered trees and shrubs (in field C) and dense Poa pratensis clones (in field A) fell outside the plots in order to maximize plot homogeneity. Spacing of plots is 0.5 m in east west directions and 2 m in north south directions (although a few deviations were caused by avoiding trees and shrubs). Drought treatments are applied through hand operated rain out shelters: 6 mil poly is rolled out when rain is at hand, and is rolled up as rain seems to have stopped. The inner 3m x 3m of each plot are actually used for study. In field A gophers are a problem. Some were trapped in 1992 but disturbance did occur. In 1993 more effort will be taken to reduce gopher disturbance.