March 16 2017

5:00 pm 1100 TLSB

EcoEvoPub Series

Graduate Student Presentations


Dita Cahyani
Department of Ecology and Evolutionary Biology, UCLA

"Delineating Marine Biodiversity in the Coral Triangle Using a Standardized Sampling Method"

Located in the Coral Triangle, Indonesia is home to a remarkable diversity of marine species. Despite being a global biodiversity hotspot, Indonesia has one of the world’s most threatened ecosystems. Increasing pollution and overfishing plague the coral reefs there. To protect and manage Indonesia’s valuable marine ecosystems, novel, standardized, and cost-effective sampling methods are needed. To measure marine diversity across Indonesia, this study uses Autonomous Reef Monitoring Structures (ARMS), devices that mimic the structure of coral reefs, serving as a proxy of the adjacent marine ecosystem. After being deployed underwater for three years, the ARMS and all the animals that have colonized them will be recovered. We will then identify the animals on each ARMS unit using next-generation DNA sequencing (NGS) techniques. The aims of the study are to determine the patterns of marine metazoan and microbial diversity across Indonesian reefs and to document the direct impact of pollution by examining diversity gradients in reefs with increasing distances from a highly polluted marine environment. The results of this study will provide valuable data to help local policy makers to manage this region’s unique biodiversity and to improve ecosystem resilience.

Lee Dietterich
Department of Geography, UCLA

"Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils"

Plant heavy metal uptake is a vital consideration in efforts to manage contaminated soils, but the factors affecting plant metal uptake remain poorly understood. Arbuscular mycorrhizal fungi (AMF) have been suggested to have important effects on plant metal uptake. However, it remains difficult to predict the magnitude and direction of these effects based on existing literature, largely because most previous studies focus on one or two plant species or metals, tend to use highly artificial growing conditions and metal applications, and rarely consider metals’ effects on plants and AMF together. Here, we used a novel field-based approach to examine both direct and AMF-mediated effects of soil concentrations on plant concentrations of 8-13 metals in five wild plant species sampled across a field site with continuous variation in Zn, Pb, Cd, and Cu contamination. Plant and soil metal concentration profiles were closely matched despite high variability in soil metal concentrations even at small spatial scales. However, we observed few effects of soil metals on AMF colonization, and no effects of AMF colonization on plant metal uptake. We conclude that manipulating soil chemistry or plant community composition directly may control landscape-level plant metal uptake more effectively than altering AMF communities. Plant species identities may serve as highly local indicators of soil chemical characteristics.











































































































































































































































































































































































































































































































































































































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