Isolated trees with high crown coverage and densities increase pasture seed rain

Abstract

Pasture and crop lands restrict seed dispersal near remnant forest fragments, especially by restricting the movements of dispersal agents and limiting propagule dispersal. Some factors can improve seed dispersal in open areas, such as the presence of high numbers of isolated trees in close proximity to forest fragments. We sought to determine if: (i) the structural characteristics and (ii) densities of isolated trees in pasture lands, and (iii) their distances from the forest fragments, infl uence seed dispersal. We installed 18 seed traps in each of six pastures (total=108 traps) bordering forest fragments distributed over 6 distance classes from the forest edges (0, 5, 10, 20, 40 and 80 m). We determined the characteristics of the plants surrounding the traps. GLM and GLMer analyses were performed and the best model was selected by AIC. We collected 8162 seeds (4722 anemochorous, 3304 epizoochorous, 72 autochorous, and 64 endozoochorous) belonging to 26 species. Our results showed that plants with high crown coverage close to forest fragments and at high densities in the pastures increased seed dispersal. Th ese results may aid future restoration of pasture lands by improving seed dispersal in this harsh habitat and promoting better connectivity between forest fragments.

Seed dispersal and seedling establishment during early-stage tropical forest recovery within old-fields

“…Directed dispersal, which is known to be common in successional landscapes(Wenny 2001), occurs when isolated vegetation experiences much greater non-random dispersal events than open pasture due to disperser preference for this vegetation and associated increased visitation rates(Howe and Smallwood 1982). Across all regions within our study, seed rain was significantly higher under isolated trees than in open pasture, adding further support for the occurrence of directed dispersal and may explain why our results are contrary toPejchar et al (2008), andVergne et al (2016) who placed seed traps along transects within open pasture.…”

Conhecimento local de agricultores familiares sobre árvores nativas em pastagens do Portal da Amazônia, MT

“…A arborização das pastagens tem sido proposta como um meio de fortalecer a sustentabilidade dos sistemas de produção a pasto, o que significa manter em longo prazo a produtividade e a persistência da forrageira, além de contribuir com aspectos ambientais como a formação de corredores ecológicos e incrementar a biodiversidade local (Martinez et al, 2014;Bernardi et al, 2016;Vergne et al, 2016;Carvalho et al, 2018). Estudos indicam contribuições positivas da arborização das pastagens para a melhoria das condições físicas, químicas e microbiológicas do solo e maior crescimento e qualidade das plantas forrageiras (Carvalho & Xavier, 2005;Pang et al, 2019).…”

Floristic diversity of patches generated by protected Ficus ‘trees outside forests’ in agricultural landscapes in Madagascar

“…Their presence in farming systems, as well as the incorporation of tree groves within farmland in an agroforestry approach, are widely recognised today as contributing to biodiversity in tropical and temperate agroecosystems (Aumeeruddy-Thomas & Michon, 2018;Genin et al, 2013). Under isolated trees, valuable biodiversity can thrive due to increased organic and mineral elements from animal excrement and vegetation litter that improve soil fertility, which then supports plant growth and species diversity (de la Peña-Domene et al, 2014;Harvey, 2000;Manning et al, 2006;Vergne et al, 2016). Ficus species (Martin et al, 2009;Rasplus et al, 2023).…”