Native macrophyte restoration in a spring-fed river ecosystem.

Restoration of native macrophytes is considered a high-priority objective in the San Marcos River in San Marcos, Texas. This study examines the effects of various factors on the short and long-term survival of seeded and transplanted native macrophytes. Neighboring invasive plants had a significantly negative effect on S. platyphylla, H. dubia, and L. repens transplant short-term survival. Radiation/canopy cover, depth, velocity, and substrate had mixed effects on transplant short-term survival among these three species. Rapid expansion of transplants to large, colony size macrophyte beds had a significantly positive effect on the long-term survival of S. platyphylla and Vallisneria sp. Regarding methods of planting the endangered Z. texana, tillers and whole plants provided higher short-term survival than seed packs. Deeper depths and presence of neighboring plants negatively affected Z. texana whole plant short-term survival and larger initial basal area positively affected tiller and whole plant short-term survival.M.S