Variation in Species and Trophic Composition of Insect Communities in Puerto Rico¹

Abstract

Insects are important participants in many ecosystem processes, but the effects of anthropogenic and natural disturbances on insect communities have been poorly studied. To describe how disturbances affect insect communities, we addressed two questions: Do insect communities return to a pre-hurricane composition? And how do insect communities change during succession? To answer these questions, we studied insect communities in a chronosequence of two abandoned pastures (5 yr and 32 yr) and a mature forest (>80 yr) that were recently disturbed by two hurricanes (Hurricane Hugo, 1989; Hurricane Georges, 1998). Although insect abundance and richness fluctuated during the study, all sites returned to pre-hurricane (Hurricane Georges) abundance and richness in less than one year. All trophic categories present before Hurricane Georges were present after the hurricane, but richness within categories fluctuated greatly. Insect richness did not increase during succession; the 5 yr site had the highest richness, the >80 yr site had an intermediate richness, and the 32 yr site the lowest. Nevertheless, the species composition of the two forested sites was different in comparison to the 5 yr site. These results suggest that trophic structure varies little in time and space, but the species composition within each trophic category is highly variable. RESUMENLos insectos participan en muchos de 10s procesos de 10s ecosistemas, sin embargo pocos estudios se han investigado el efecto que tienen las perturbaciones naturdes y antropogknicas sobre las comunidades de insectos. Para describir cbmo estas perturbaciones afectan a las comunidades de insectos, nos planteamos dos preguntas: regresan las comunidades de insectos a la composicibn previa desphes de un huracin? Y cbmo cambian las comunidades de insectos durante la sucesibn? Para contestar estas preguntas, estudiamos las comunidades de insectos en una cronosecuencia de dos pastides abandonados (5 afios y 32 aiios) y un bosque maduro (>80 aiios) que heron recientemente perturbados por dos huracanes (Huradn Hugo, 1989; Huracin Georges, 1998). Aunque la abundancia y riqueza de insectos fluctub durante el estudio, todos 10s sitios recuperaron 10s niveles prehuracin (Huracin Georges) en menos de un afio. Todas las categorias trbficas presences antes del Huracin Georges siguieron presences despub del huracin, pero la riqueza dentro de las categorias fluctub ampliamente. La riqueza de insectos no aumentb durante la sucesibn; el sitio de 5 af~os tuvo la riqueza m h alta, el sitio de >80 aiios tuvo una riquaa intermedia, y el sitio de 32 aiios t w o la riqueza m h baja. Sin embargo, la composicibn de especies de 10s dos sitios de bosque h e diferente en comparacibn al sitio de 5 aiios. Estos resultados sugieren que la estructura trbfica varia poco en tiempo y espacio, pero la composicibn de especies de las categorias trbficas es muy variable.

Changes in Patterns of Understory Leaf Phenology and Herbivory following Hurricane Damage

“…In Florida, many common herbivores and seed predators disappeared for more than seven months afcer Hurricane Andrew (Pascarella 1998, Koptur et al 2002. Other studies have shown a diversity of responses by insects to hurricanes, with some groups increasing and others decreasing (Torres 1992;Schowalter 1994Schowalter , 1995Garrison & Willig 1996;Schowalter & Ganio 1999;Barberena-Arias & Aide 2002). Without data on specific herbivore species, it is difficult to determine if this was the major reason for lower levels of herbivory in our study.…”

Leaf‐Litter Arthropods in Restored Forests in the Colombian Andes: A Comparison Between Secondary Forest and Tree Plantations

“…We must bear in mind that at our site, plantations are presently embedded in a forest matrix. Although soils were profoundly disturbed by cattle ranching for several decades, there were remnant forest patches in the region that presumably served as recolonization sources and litter insect communities may recover rapidly after a perturbation (Barberena‐Arias & Aide 2002). In this case, the best chance to recover a fully functional tropical forest, with a species composition and structure resembling the original forest, is probably through natural regeneration (Murcia 1997), although preliminary work to restore soils may be necessary.…”

Soil Biology Research across Latitude, Elevation and Disturbance Gradients: A Review of Forest Studies from Puerto Rico during the Past 25 Years

“…Barberena-Arias and Aide [90] and Osorio-Pérez et al [91] studied litter insect diversity and trophic composition during plant secondary succession in Puerto Rico. They found that arthropod species composition was significantly different between early and intermediate/late forests where early successional habitats had few unique species, and intermediate/late habitats had more species specific to woody habitats-suggesting the recovery of arthropod diversity during plant secondary succession is dependent not only on the increase of wood and concomitant resources but also on the recovery of plant diversity [92].…”