Seedling recruitment and cover responses to rock detention structures paired with seed in the Chihuahuan Desert

Abstract

Drylands are susceptible to erosion by wind and water. Thus, the reestablishment of vegetation is a crucial focus of watershed restoration in order to stabilize soils and improve water infiltration. Currently, limited research exists quantifying vegetation responses to rock detention structures (RDS) in the Chihuahuan Desert, and no studies have quantified the effects of RDS paired with seed introduction. Our study area in the Rincon Arroyo Watershed, in southern New Mexico, tested the hypotheses that two types of RDS, micro‐catchments and stone‐lines paired with seeding, support increases in seedling recruitment and vegetation cover compared to untreated controls. This study also tested whether the application of seed to RDS alters plant communities in comparison to controls. One season after seeded RDS were applied, seedling recruitment, cover, and plant community responses were evaluated at treatment and control areas. Seeded stone‐lines showed significantly greater seedling recruitment (2×) and cover (0.3×) than controls (p < 0.05), whereas seeded micro‐catchments showed significantly greater cover (0.3×) than controls (p < 0.05) but did not exhibit significant differences in seedling recruitment compared to controls (p > 0.05). The lack of a significant difference between plant communities at treatment and control areas (p > 0.05) suggests that the addition of seed had little to no effect on plant communities or positive responses in seedling recruitment and cover. These results suggest that stone‐lines and micro‐catchments, alone, can support vegetation establishment in degraded dryland watersheds without the addition of seed.