fossil creek stream restoration

Stream Restoration

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 After Control Impact), we determined the relative importance of flow restoration versus non-native fish removal Read more…

Researcher climbing a large redwood tree.

Plant Ecophysiology

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 diverse environments ranging from deserts to rainforests. A longstanding interest is the biophysical and ecological Read more…

Fossil Creek, Arizona with fall foliage in background.

Riparian Ecosystems

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 power generation impose major demands on the defining feature of aquatic ecosystems: water. Work at Read more…

Core of permafrost with a lens of ice at its deepest end.

Soil Microbial Ecology

Soil microorganisms are biogeochemical forces of global significance. They affect nutrient availability to plants, the amount of carbon stored in soils, and the evolution of the atmosphere over geologic time. The research we conduct in Ecoss examines many aspects of soil microbial ecology. Metabolic Flux Analysis of Soil Microbial Communities Read more…

Detail of Yellow Fremont Cottonwood Leaves in Autumn Stream

Leaf Litter Effects on Stream Ecosystems

As part of a large interdisciplinary team, with funding from the National Science Foundation, we have studied how genetic and environmental factors affect leaf litter quality in cottonwoods and other riparian species, and how these effects are manifest in aquatic ecosystems.

Close-up of cheatgrass

Soil Microbial Legacies of Invasive Species

Invasive plants like cheatgrass have huge and costly effects on ecosystems. Restoring native plants to areas invaded by cheatgrass is challenging, and one explanation for poor seedling establishment is the absence of beneficial soil microbes. In this project, we are testing the idea that restoring microbial communities promotes ecosystem recovery and the re-establishment of native plants.