Re-seed or not re-seed? Factors affecting rangeland grass-seedling establishment. Review

Abstract Although seedling has a significant role in the maintenance of plant diversity, productivity, and biochemical cycles in the rangeland. However, little is known about the influence of environmental factors in the seedling establishment, as well as the differences in the morphological development among species. To understand of seedlings establishment becomes of crucial importance to improve the success of reseeding of natural ecosystems. This literature review investigated which factors are addressed with failures in the seedling establishment of native grasses in rangeland conditions. Germinating seed grass is not big a problem if there are optimum environmental conditions. The heart of the matter is to ensure the survival and growth of these seedlings until the complete establishment as plant. The moisture and temperature of soil are the main environmental factors associated with failures in seedling establishment. The studies reviewed showed that annual plants have higher seedling growth rates, however lower allocation to reproductive structures when compared to mid-seral and late successional plants. These differences also promote different rates of seedling survival rate, with early seral grass showing higher rates than late seral. Apparently, the main cause of seedlings failures in the establishment is correlated with the development and extension of the adventitious roots. Where the reports describe that seedling emerge quickly and abundantly in most grasses, but the seedlings died between six and ten weeks of age. It was addressed that a plant can germinate and sprout the primary roots, however, for an unknown reason the plant does not sprout the adventitious root.