Exploring Plant-Plant Interactions and Nutrient Manipulation as Strategies for Thorn Scrub and Thorn Forest Restoration

Restoration of thorn scrub and thorn forest communities in South Texas is hindered by harsh environmental conditions and hypercompetitive invasive grasses. The success of thorn scrub/thorn forest restoration efforts depends on increasing seedling survival and growth by reducing stress after transplantation. Four experiments evaluated initial effects of plant-plant interactions and nutrient manipulation on thorn forest restoration. High density planting along with the use of nurse plants look promising; survival was generally higher under these conditions and growth was unaffected or in the case of high-density planting, promoted. Nutrient sequestration by sorghum had little effect on seedling performance and cover of grass and other plants, but localized fertilization benefited the seedlings. Allelopathy is promising; however, field studies must be performed to confirm benefits in the field. Overall positive plant-plant interactions resulted higher survival and growth in this study and should be implemented as thorn scrub and thorn forest restoration strategies