BoCP Design: US-China-Sao Paulo: Functional Biodiversity in Streams on a Changing Planet in Tropical, Subtropical, and Temperate Climates

Humans have globally altered the fundamental processes maintaining biodiversity by converting natural land cover for human uses. Freshwater ecosystems have been disproportionally impacted by global land use change, with aquatic insects experiencing sharp declines in recent years. This project will link the three dimensions of biodiversity across temperate, subtropical, and tropical regions on three continents to provide comprehensive understanding of how human land use affects aquatic life, in particular caddisflies, a highly diverse and widespread group of aquatic insects.

Identifying broad patterns of aquatic ecosystem health in response to land use change is a major goal of conservation ecology, but research has struggled for decades with this goal for two main reasons, which this study address. First, most biodiversity research has considered only the number of species (“taxonomic diversity”). Taxonomic diversity is incomplete because it does not provide information about (a) the actual roles the organisms play in their environment (“functional diversity”), or (b) how shared evolutionary history among species may cause them to respond similarly to land use change (“phylogenetic diversity”).

The second roadblock for identifying broadly applicable patterns is that most field studies are conducted only in a single region, limiting resulting conclusions to that region. This project will contribute to the collections and identification of caddisfly species across three continents, provide international training and networking opportunities, and deliver aquatic insect identification workshops in both Brazil and China.

It will also launch long-term pollution-monitoring programs in Brazil and China and will train a diverse group of over 20 undergraduate and graduate students, as well as postdoctoral researchers.

This project will focus on caddisflies—a highly diverse, widespread, and imperiled group of aquatic insects. The project team will sample larval and adult caddisflies in streams across gradients of land use change—from streams whose watersheds contain mostly natural land cover, to those that have been largely converted to agriculture and/or urbanization.

Work will occur simultaneously in three of the world’s major biomes: the temperate Blue Ridge ecoregion of the southeastern United States, the subtropical Qiantang River of southeastern China, and the tropical Paranapanema River basin of southern Brazil. This project consists of a developing collaboration between researchers at Clemson University (CU, United States), Universidade Estudal Paulista (UNESP, Brazil), and Nanjing Agricultural University (NJAU, China) in which researchers will conduct field work in their respective nations.

In addition, CU researchers will compare modern fauna with fauna sampled from the same streams in 1969 and the 1980s and will travel to China and Brazil to teach aquatic insect identification courses and to transport specimens for DNA sequencing. Researchers at NJAU will conduct cutting-edge genetic analyses to enable calculation of phylogenetic diversity and identification of larvae, and collaborators at UNESP will provide expertise in community analysis and spatial statistics.

This project will 1) build a trans-continental, multidimensional database of caddisfly diversity; 2) quantify multidimensional caddisfly responses to human land use change in different ecoregions on three continents; and 3) quantify homogenization of caddisfly assemblages within regions through time. This project will provide new inferences and information to help identify threats and slow aquatic biodiversity loss on a rapidly changing planet.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.