We compare the distribution of reproductive traits in woody vegetation of 10 wet tropical forests in northeastern Costa Rica. Based on quantitative sampling of seedlings, saplings, and trees, we assess whether particular sexual systems, pollination syndromes, or seed-dispersal modes are associated with successional stage, prior selective logging, woody growth forms, or patterns of abundance or rarity. We further examine the phylogenetic structure of these traits in the regional woody flora, testing explicit hypotheses regarding phylogenetic clustering of reproductive traits and habitat distributions. Animal dispersal and insect pollination predominate across all forest types and size classes. In second-growth trees, relative abundance of species with explosive dispersal, hermaphroditic flowers, and insect pollination is higher, and relative abundance of species with animal dispersal and mammal pollination is lower, compared to old-growth and logged forests. Overall, dioecy and wind dispersal are more frequent than expected in canopy trees, and hermaphroditic flowers are more frequent than expected in shrubs. Reproductive traits, growth-form traits, and relative abundance patterns show significant clustering within the supertree phylogeny. Patterns of trait distribution across forest types are closely linked with patterns of floristic composition at the genus and family level. Species-level associations among reproductive traits and woody growth form can be explained by phylogenetic correlations. Wind dispersal and hummingbird pollination are significantly concentrated in clades with hermaphroditic flowers, whereas wind pollination is concentrated in clades with unisexual flowers. Legacies of both phylogenetic history and forest disturbance structure the distribution of reproductive traits within and among tropical wet forest communities.
The relationship between toughness and herbivory is complex; despite the negative findings of some recent authors for dicots we hypothesize that either greater toughness or late folding can protect monocot leaves against herbivorous insects in tropical lowland rain forest, and that the relative importance varies widely with species. The difficulties of establishing unequivocally the roles of leaf toughness and leaf folding or rolling in a given case are discussed.
At an historic moment, when Colombia is emerging from 60 years of armed conflict, the 7-year-old Colombian Network for Ecological Restoration (Red Colombiana de Restauración Ecológica [REDCRE]) has created four subnational nodes, and is actively developing several more. All of this is taking place in the context of the Ibero-American and Caribbean Society for Ecological Restoration (Sociedad Ibero-Americana y del Caribe de la Restauración Ecológica [SIACRE]). In mid-November 2014, over 200 representatives of government agencies, academia, private enterprises, and nongovernmental organizations (NGOs) from the entire country attended a symposium to launch the Antioquia Province node, and take stock and plan the way forward. There are bright prospects of transdisciplinary and public-private collaborations in Colombia for ecological restoration and restoration of natural capital as part of a strategy to transition smoothly to a post-conflict era. We suggest some goals and guidelines to help move forward an ambitious agenda to mainstream ecological restoration.
We examined whether the experimental exclusion of large mammalian and small rodent seed predators had differing effects on seedling recruitment under natural seed rain conditions. In both primary and late‐successional secondary forested areas, exclosure experiments using natural seed densities were designed to assess seedling recruitment. To assess the differences in seedling recruitment, we monitored three exclosure treatments (1.2 m radius/1.5 m height) in two forest types (primary vs. late‐successional secondary forest): (1) fenced exclosures that excluded large mammals; (2) fenced exclosures that excluded both large and small mammals; and (3) open controls. Within each exclosure treatment, we marked and identified all seedlings at the beginning of the experiment (February 2001), followed the marked seedlings' fate for a year, and then marked and identified all new seedlings after a year. Two preliminary findings were generated from these data: for some tree species, small rodents and large mammals have differential effects on seedling recruitment, and the effect of excluding mammals did not differ with habitat type (primary vs. late‐successional secondary forest). These preliminary results highlight the need to examine further how the effects of small rodent and large mammal exclusion may affect species‐specific seed predation and seedling recruitment in a variety of habitat/land use types (e.g., primary forest, late‐successional forest, and early‐successional forest).
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