Ant communities respond to a large-scale disturbance along an elevational gradient in Puerto Rico, USA

Large scale disturbances are known to significantly alter aspects of both species diversity and ecosystem function. In the Caribbean, hurricane events are a significant form of disturbance, the effects of which have been shown to alter food web function, especially in the terrestrial environment. Although hurricanes have been studied from a variety of their effects on ecosystems, there is little research on how these storms affect species along elevational gradients. Within terrestrial habitats, ants form the basis of many food webs, being both numerically dominant and functioning in a variety of roles within the food web. On September 20th, 2017 Hurricane Maria, a category 4 storm, crossed over the island of Puerto Rico, causing significant damage to both human and natural systems. We collected data on ant abundance and composition from 150 samples of leaf litter along a 700 m elevational gradient during June the year of and after the storm event. Ant abundance increased by 400% after the storm with many common ant species seeming to benefit, especially at lower elevations. There were subtle changes in ant richness, with declines generally after the storm, but yet again this response was dependent on elevation. This is one of the first studies to consider how terrestrial insect communities are affected by large hurricane events across elevations, and our results are in contrast to past work showing declines in ant abundance after such storms.Abstract in Spanish is available with online material. Se sabe que las perturbaciones a gran escala alteran significativamente aspectos tanto de la diversidad de especies como de la funcion de los ecosistemas. En el Caribe, los huracanes son una forma importante de perturbacion, cuyos efectos se ha demostrado que alteran la funcion de la red alimentaria, especialmente en el medio terrestre. Aunque los huracanes se han estudiado a partir de una variedad de efectos en los ecosistemas, hay pocas investigaciones sobre como estas tormentas afectan a las especies a lo largo de gradientes altitudinales. Dentro de los habitats terrestres, las hormigas forman la base de muchas redes alimentarias, siendo numericamente dominantes y realizando una variedad de funciones dentro de la red alimentaria. El 20 de septiembre de 2017, el huracan Maria, una tormenta de categoria 4, cruzo la isla de Puerto Rico, causando danos importantes a los sistemas humanos y naturales. Colectamos datos sobre la abundancia y composicion de hormigas de 150 muestras de hojarasca a lo largo de un gradiente de elevacion de 700 m durante junio del ano y despues del evento de la tormenta. La abundancia de hormigas aumento en un 400% despues de la tormenta y muchas especies de hormigas comunes parecieron beneficiarse, especialmente en elevaciones mas bajas. Hubo cambios sutiles en la riqueza de hormigas, con disminuciones generalmente despues de la tormenta, pero una vez mas esta respuesta dependio de la elevacion. Este es uno de los primeros estudios que considera como las comunidades de insectos terrestres se ven afectadas por grandes huracanes en diferentes elevaciones, y nuestros resultados contrastan con trabajos anteriores que muestran disminuciones en la abundancia de hormigas despues de tales tormentas. We collected data in the Luquillo Experimental Forest of Puerto Rico on ant abundance and composition from 150 samples of leaf litter along a 700 m elevational gradient during June the year of and after Hurricane Maria. Ant abundance increased by 400% after the storm with many common ant species seeming to benefit, especially at lower elevations, with subtle changes in ant richness, with declines generally after the storm, but yet again this response was dependent on elevation. This is one of the first studies to consider how terrestrial insect communities are affected by large hurricane events across elevations, and our results are in contrast to past work showing declines in ant abundance after such storms.image