GROWTH AND SURVIVAL OF PROSOPIS GLANDULOSA SEEDLINGS ASSOCIATED WITH SHADE AND HERBACEOUS COMPETITION

Greatest growth of honey mesquite seedlings was in full sunlight when there were no competitors. Plants in shade without competitors or in full sunlight with competitors had intermediate growth, while those in shade with competitors were the smallest. Prosopis glandulosa germination in the laboratory was 93 ± 5% versus 2%-19% in the field. No seedlings survived after one growing season in 2 grassland plots with high biomass, compared with 8% in herbicided plot. Lack of P. glandulosa seedling germination and growth under mature P. glandulosa trees appears to be the result of reduced light levels and herbaceous plant competition. These factors also result in low numbers of seedlings in grasslands and, coupled with herbivory or fire, could account for their absence. -from Authors