Archive by Category "Land and Water"

Land and Water

At Ecoss we study many aspects of our environment, including plant physiology of redwood and pinyon pine trees, invasive species, soil, aquatic ecosystems, leaf litter decomposition, aquatic macroinvertebrates, food web dynamics, and river and wetland restoration.

Fossil Creek Restoration Fossil Creek, Paul S. Hamilton 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 on the populations densities of native fish and invertebrates. What were the effects of antimycin A on aquatic invertebrates? One of the unwanted side effects of chemical treatments to remove exotics is their propensity to...
Researcher climbing a large redwood tree.

Researcher climbing a large redwood tree. 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 determinants of height and size growth in the world’s giant trees, including the towering redwoods of California and massive eucalypts of Australia. Here we’ve learned that the inescapable influence of gravity increases water stress...
Fossil Creek, Arizona with fall foliage in background.

Fossil Creek, Arizona in the fall. Copyright Steve Rich 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 Ecoss assesses how changes to aquatic ecosystems affect their functioning, from a community and ecosystems perspective. Our work has involved two major ecosystems in the southwest: the Colorado River, where the...

Overview The identities of organisms profoundly influence ecosystems, and microbial diversity is vast. The obvious disconnect between this diversity and its treatment in C cycling models is perhaps the best manifestation of the common complaint that so much physiology, taxonomy, ecology, and diversity is ignored when microbial communities are described with boxes and arrows. A recent report from the American Society for Microbiology captured this complaint by depicting on the cover the hackneyed “black box” of microbial ecology, although the report emphasized the promise of new approaches by showing the...
Core of permafrost with a lens of ice at its deepest end.

Permafrost and ice core 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 Microbial processing of soil organic compounds is a key ecosystem process that largely determines the soil carbon cycle. Yet, we know little about the biochemical pathways involved, and how these pathways respond to environmental change. At...
Detail of Yellow Fremont Cottonwood Leaves in Autumn Stream

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

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.