The Effect of Restoration Treatments on Seed Dispersal and Seedling Establishment Limitation in a Tropical Agricultural Landscape

Abstract

Seed dispersal and seedlings establishment limitation are variable and depend upon the environmental conditions that habitats provide. We know that limitations are higher in degraded ecosystems, but little we know about effect of restoration on these limitations through time. Dispersal and establishment limitations change according to life strategies of species, their dispersal mode and the changes in the restored environment. We tested the changes in limitations in 12 common woody species from 2007 to 2015 in three different restoration scenarios (tree plantings of animal dispersed species, tree plantings of wind dispersed species and plots that simulate natural succession). Both types of planted plots had a higher decrease in dispersal limitation than under natural regeneration, with plots planted with animal dispersed trees showing up to 15% less dispersal limitation compared to the other treatments. Even though species had a different trajectory of dispersal and establishment limitations, general trend have an average reduction of 23±18% in dispersal limitation for animal dispersed species, while limitations for wind dispersed species increased on average 6±18% throughout time. Higher limitations for pioneers establishing in five-year-old plantings (2011 is still pre fruiting conditions for the most part) were expected, but for later successional animal dispersed Bursera simaruba, a small decrease in dispersal limitation meant a big decrease in establishment limitation. All in all, planted plots influenced seed dispersal and seedling establishment limitation even before general fruiting patterns were observed in the planted plots favoring animal dispersed trees over wind dispersed trees.