Arthropods are among the most diverse and abundant group of animals found in tropical forests. Arthropods that live in litter and soil provide a number of ecosystem services such as maintenance of soil structure and nutrient cycling. Despite the key ecological roles of these organisms, very little is known about arthropods communities in high elevation tropical ecosystems. We are studying patterns of litter arthropod abundance and diversity in two important habitat types, puna grassland and remnant Polylepis forests, across altitudinal gradients in the tropical Andes.
Overview of our surveys from 2013 and 2014
Land cover transformation and climate change are predicted to be major drivers of biodiversity loss in tropical ecosystems. Establishing baseline information on current distributions of biodiversity is critical for understanding the impacts of environmental change. This is the first study to examined patterns of litter arthropod abundance and diversity in two important habitat types, puna grassland and remnant Polylepis forests, across high-elevation gradients in the tropical Andes. Pitfall traps were placed in nine adjacent forest and grassland sites between 3800-4400 m in three major valleys on the western slope of the Cordillera Blanca in Huascarán National Park, Peru. We found that litter arthropod richness, diversity, and abundance were significantly greater in grasslands compared to forests; however, richness and diversity did not vary with increasing elevation. Litter arthropod abundance declined with increasing elevation in grassland but not forest suggesting that forests provide more stable habitats over elevation. Arthropod community composition between the habitats was quite distinct pointing up the key role of remnant Polylepis forests in conserving biodiversity in high-elevation ecosystems in the tropical Andes.
Abundance of litter arthropods in Polylepis forest and Puna grassland at nine sites across elevational gradients.
NMDS plot illustrating the differences in community composition of litter arthropods between Polylepis forest (black circles) and Puna grassland (open triangles).