Siembra directa de Brosimum alicastrum Sw. (Moraceae) y Enterolobium cyclocarpum (Jacq.) Griseb. (Mimosaceae) en diferentes habitats en el trópico seco del centro de Veracruz

Abstract

Secondary forest in the seasonal tropics is usually dominated by a few pioneer tree species (usually wind-dispersed), while animal-dispersed species with large seeds may be absent. Several studies have shown that directly seeding these tree species in abandoned pastures can be successful; however, information is lacking about the optimal habitat conditions for sowing. We selected two large-seeded zoochorous canopy tree species that are common in the semi-deciduous tropical forest of central Veracruz, Mexico: Brosimum alicastrum and Enterolobium cyclocarpum. Their seeds were sown in seven habitats: six forming a gradient of increasing vegetation structure, from active pasture to 10-year-old secondary forest, and an old-growth forest. We assessed seed predation by granivores, protecting half of the seeds in wire cages. For a year we monitored seedling emergence, survival and growth, re-visiting the sites four-and-a-half years later. Seedling emergence was relatively high (75% in Brosimum, 60% in Enterolobium) and fairly even among habitats. Surprisingly, no seeds were removed by granivores. Enterolobium seedling survival and growth was higher in open habitats (around 60% survival up to a year) than in habitats shaded by woody plants (<10%). For Brosimum, the reverse was true; its seedlings survived and grew better under a dense woody canopy (>80% survival) than in open sites (0%). Our results show that abandoned pastures and secondary forests can be successfully enriched by directly seeding poorly-dispersed forest canopy tree species, if the right habitat for sowing is chosen with care and based on the ecology of seedling establishment of the desired species.Key words: forest recovery, large-seeded trees, secondary forest, seed predation, seedling establishment, semi-deciduous tropical forest. 100: 107-134 (2012) 108 RESUMEN Los acahuales (i.e. selvas secundarias) de zonas tropicales secas o estacionales, suelen ser pobres en especies arbóreas y dominados por unas cuantas especies de arbustos y árboles pioneros, usualmente dispersados por viento, siendo notable la ausencia de plantas arbóreas del dosel cuyas semillas relativamente grandes dependen de vectores animales para su dispersión. Varios estudios han encontrado que la siembra directa de especies arbóreas zoócoras con semillas grandes, en pastizales abandonados puede ser una práctica exitosa para enriquecer y acelerar la sucesión secundaria. Sin embargo, todavía no se conocen cabalmente las condiciones de hábitat o etapa sucesional óptima para realizar la siembra directa de semillas de árboles de fases sucesionales tardías. En este estudio seleccionamos dos especies arbóreas con semillas zoócoras relativamente grandes, que suelen formar parte del dosel de las selvas sub-caducifolias del centro de Veracruz: Brosimum alicastrum y Enterolobium cyclocarpum. Las sembramos en siete hábitats; seis de ellos representando un gradiente de menor a mayor complejidad estructural o desarrollo sucesional, desde pastizal activo hasta acahual de 10 años y el hábit...

Genetic diversity of Enterolobium cyclocarpum in Colombian seasonally dry tropical forest: implications for conservation and restoration

“…Our finding that suitable areas for the species are not expected to be severely impacted by the negative effects of climate change bodes well for its future use in tree planting projects. While a growing body of knowledge on the sexual and asexual propagation and management of E. cyclocarpum exists (Rodríguez-Sahagún et al 2007;Laborde and Corrales-Ferrayola 2012;Ekamawanti et al 2013;Obando and Moya 2013), limited attention has thus far been given to the genetic quality of planting material. Ensuring that reproductive material of E. cyclocarpum used in tree planting efforts will survive, thrive, and establish viable and resilient populations in the long term requires (1) adequate planning to identify the seed sources that are best matched to the conditions of the planting site and (2) application of good seed collection protocols (Thomas et al 2014(Thomas et al , 2015a.…”

Moving carbon between spheres, the potential oxalate-carbonate pathway of Brosimum alicastrum Sw.; Moraceae

“…However, the concentrated production of druse crystals in the lamina of B. alicastrum foliar tissue could distribute UV light to chloroplasts, increasing incident UV absorbency in understory environments, as originally hypo th esise d by Franceschi (2001) and later demonstrated experimentally by Kuo-Huang et al (2007) in Peperomia glabella. This hypothesis explains the observed decrease in subject foliar CaOx concentration with age, while also explaining B. alicastrum's high survival rates under dense canopy (>80 %; Laborde and Corrales-Ferrayola 2012). Therefore, a role for B. alicastrum CaOx druse crystal production in the maximisation of incident UV light is hypothesised.…”

Gone with the wind: Negative genetic and progeny fitness consequences of habitat fragmentation in the wind pollinated dioecious treeBrosimum alicastrum

“…Seeds of B. alicastrum are eaten fresh and dry mixed with corn meal to make bread or beverages with a flavor similar to coffee (Peters and Pardo‐Tejeda, 1982; Pérez‐Pacheco et al, 2014). In fragmented forest sites, as a result of current management practices, female trees are preferred and left in the forest by peasants (Laborde and Corrales‐Ferrayola, 2012), which may have negative effects on effective population sizes, sex ratios, genetic diversity, and progeny vigor.…”