Detail of Yellow Fremont Cottonwood Leaves in Autumn Stream
Describing the role of leaves in aquatic ecosystems based on functional communities, rather than structural communities (e.g. presence/absence), provides a useful way of describing the community and how different leaf types function as food resources. This approach also allows one to determine how C and N function and flow through aquatic food webs.
Research conducted by the Marks Lab has found that different riparian leaf species function as substrate for specific microbes. Using Q-PCR methodology, we have found the microbes are keying in on the specific functions provided by each leaf species.
The research conducted by the Marks Lab challenges the notion that decomposition alone determines the leaf quality, suggesting instead that different leaf types benefit aquatic insects in different ways: some insects use slow-decomposing leaf litter for habitat and its temporal longevity, while others use fast-decomposing litter with more immediate nutrient release. This leaf litter paradigm is exemplified by the finding that up to 25% of the leaf litter from Fremont cottonwood is unavailable to microbes compared to that of narrowleaf cottonwood; the narrowleaf litter continues to hold C and N and provide resources to microbes for a much longer period of time. Further, the leaves of these two species leach at different rates and provide both immediate and longer-term food resources for aquatic insect communities.
Fossil Creek Restoration Can we restore a river after a century of disturbance? Research in the Marks Lab has addressed the following questions: How did native species respond to restoration? Employing a BACI design (Before Read more…
Ecoss studies the interactions of plants with their physical and biotic environments at a fundamental level common to all organisms: gas exchange, energy balance, and water relations. We explore how plants make a living in Read more…
Aquatic ecosystems in the southwestern US are among the most threatened in the country: rates of species loss are high, with few remaining refuges for natives, and water extraction for human use and diversion for Read more…