Strategies to persist in the community: soil seed bank and aboveground vegetation in Patagonian pine plantations

RAGO, MARÍA MELISA; URRETAVIZCAYA, MARÍA FLORENCIA; ORELLANA, IVONNE ALEJANDRA; DEFOSSÉ, GUILLERMO EMILIO

APPLIED VEGETATION SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 vol. 23 p. 254 - 265

1402-2001

In terms of biodiversity conservation, forest plantations are often considered problematic because they usually have negative effects on natural ecosystems. Soil seed banks could play an important role in restoring vegetation that was originally present, by recruiting species that disappeared aboveground. We addressed this topic in plantations located in the Patagonian steppe by asking the following questions: Are richness, abundance and composition of steppe aboveground vegetation and soil seed bank affected by plantations? Is species composition of aboveground vegetation and soil seed bank similar in plantations and in the steppe? We selected three plantations located in the steppe, and delimited three sectors: steppe, plantation edge and plantation interior. We compared richness and abundance by species origin and growth form among sectors for aboveground vegetation and soil seed bank compartments, using generalized linear mixed models. We compared species composition for each compartment and between them using permutational multivariate analysis of variance and non-metric multidimensional scaling. In aboveground vegetation we found richness and abundance decrease and composition changes from the steppe to the plantation interior. Richness and abundance of the soil seed bank did not show differences among steppe and the plantation sectors, although composition was different among them. Aboveground vegetation and soil seed bank species composition was always different; native perennial herbs and shrubs were predominant in the aboveground vegetation while exotic annual herbs dominated the soil seed bank. Our findings suggest that plant recruitment from the soil seed bank would not be sufficient for restoring depleted species pools in aboveground vegetation of plantations. Therefore, actions promoting native species reestablishment and exotics control should be considered to reach the aim of restoring biodiversity in former plantations.