Leguminous seedling establishment in Tamaulipan thornscrub of northeastern Mexico

Abstract

Due to extensive land clearing in northeastern Mexico, there is an increasing need for restoration for which knowledge on plant establishment biology becomes a priority, for restoration practices. In here we tested the influence of current environmental variation on the establishment biology of common woody species from Tamaulipan thornscrub. Seedling establishment was monitored; four native species ( Acacia berlandieri Benth., Ebenopsis ebano (Benth.) Coult, Havardia pallens (Benth.) Brintton and Rose, Prosopis laevigata (Humb & Bonpl. ex. Wild.) M.C. Johston), and one exotic species ( Leucaena leucocephala (Lam.) de Wit). Seedling emergence, seedling survivorship, length of stems and number of leaves were evaluated over 1 year in environments with different light regimes: (i) dense thornscrub; (ii) thornscrub edge; (iii) cleared thornscrub (direct sunlight). Ten plots of 4 m 2 (2 m × 2 m) were sampled in each environment. Seedling emergence occurred on spring and late summer and was greater on dense thornscrub for all species. Native species had higher survivorship and growth and had more leaves in dense thornscrub than in other environments. Exotic L. leucocephala had similar survivorship, shoot length and number of leaves across environments. All seedlings from all species died by late spring, possibly due to environmental stress. Seedling survival was longer for all native plants, as there were surviving seedlings in early spring for all species but not of exotic L. leucocephala. Perhaps mainly as a result of high temperature and low humidity. Additional watering, shading and moisture retaining gels should thus be considered when rehabilitation programs are made with seeds and seedlings in the region.