Direct seeding of forest species for ecological restoration in the Pampa – Atlantic Forest transition

ABSTRACT

Ecotonal transition regions are neglected in floristic and ecological restoration studies, despite their vast occurrence and socioeconomic relevance. The present study evaluated the emergence and initial development of forest species from the ecotonal transition between the Pampas and the Atlantic Forest, in direct seeding, using inter-row green manure (Canavalia ensiformis). We tested sixteen species and evaluated emergence, survival and seedling height rates monthly for twelve months. Six species emerged and established themselves, with mean emergence values of 7%, survival rate of 73% and height of 20 cm. Larger seed species had higher emergence rates. All legumes in the study emerged (Enterolobium contortisiliquum, Parapiptadenia rigida, Bauhinia forficata and Mimosa bimucronata). The pitangueira (Eugenia uniflora) was the only recalcitrant seed species to present emergence. The coverage of jack bean provided greater establishment for Annona sylvatica and Enterolobium contortisiliquum, with statistical significance by the Wilcoxon test. For future studies on direct seeding, we recommend further study on the quality and size of forest seeds, responses in temperate climates, ideal sowing time, density and depth. For the green cover we recommend a higher sowing density and intercropping with other species, including native herbs and shrubs.

Keywords
Ecotonal transition; Early development; Temperate climate