Moisture Range to Which Species is Well Adapted 

Plant response to moisture is subject to many variables - ele­vation, exposure, total heat units, season when greatest amount of moisture is received and runoff losses, to name a few.  "Moisture", as used here, includes all sources -- annual precipitation, natural flooding, irrigation, etc.  Some species may do well in rows under lower moisture than shown, since this makes the available moisture more effective. 

In defining a moisture range for a species, the lower limit is the minimum at which the species gives satisfactory production in solid stand.  The upper limit is the amount beyond which the species will not utilize additional moisture.  If no upper limit is given it means it does well under maximum precipitation experienced in forage producing areas in Montana, or under irrigated conditions. 

(Ratings are expressed as inches of moisture).