Germinable Alkali Sacation Seed Content of Soils in the Rio Puerco Basin, West Central New Mexico

Abstract

Barren sites are interspersed through native stands of alkali sacaton (Sporbolus airoides Torr.) in west central New Mexico. To determine if these sites remain bare because of lack of viable seeds, soil samples were collected three times each year for three years, and emerging sacaton seedlings were counted. Fewer germinable seeds were found in soil from barren sits than in soil from within stands. Moreover, the number of germinable seeds varied with time of collection. Seed movement from stands to barren sites were determined through collection made weekly during the period of seed dissemination. It was found that a substantial number of alkali sacaton seeds cross the barren sites, mainly through wind action. As many as 40—50 seeds/sq. ft. (400—500 m2) were collected 25 to 50 feet (7.6 to 15.2 m) from established stands. The results suggest most seeds are blown across the barren sites. The few seeds trapped in microsites in the soil soon after dissemination apparently are either removed by wind water animals, or insects, or are killed due to unfavorable moisture—temperature conditions.