Southwest Biological Science Center
Population history provides foundational knowledge for utilizing and developing native plant restoration materials
A species’ population structure and history are critical pieces of information that can help guide the use of available native plant materials in restoration treatments and decide what new native plant materials should be developed to meet future restoration needs. In the western United States, Pseudoroegneria spicata (bluebunch...Massatti, Robert; Prendeville, Holly R.; Larson, Steve; Richardson, Bryce A.; Waldron, Blair; Kilkenny, Francis F.
Where have all the turtles gone, and why does it matter?
Of the 356 species of turtles worldwide, approximately 61% are threatened or already extinct. Turtles are among the most threatened of the major groups of vertebrates, in general, more so than birds, mammals, fishes or even the much besieged amphibians. Reasons for the dire situation of turtles worldwide include the familiar list of impacts to...Lovich, Jeffrey E.; Ennen, Joshua R.; Agha, Mickey; Gibbons, J. Whitfield
Approaches for improving field soil identification
Use of soil survey information by non-soil-scientists is often limited by their inability to select the correct soil map unit component (COMP). Here, we developed two approaches that can be deployed to smartphones for non-soil-scientists to identify COMP from the location alone or location together with easily observed field data (i.e., slope,...Fan, Zhaosheng; Wills, Skye A.; Herrick, Jeffrey E.; Nauman, Travis; Brungard, Colby W.; Beaudette, Dylan E.; Levi, Matthew R.; O’Geen, Anthony T.
Soil property and class maps of the conterminous United States at 100-meter spatial resolution
With growing concern for the depletion of soil resources, conventional soil maps need to be updated and provided at finer and finer resolutions to be able to support spatially explicit human–landscape models. Three US soil point datasets—the National Cooperative Soil Survey Characterization Database, the National Soil Information System, and the...Ramcharan, Amanda; Hengl, Tomislav; Nauman, Travis; Brungard, Colby W.; Waltman, Sharon; Wills, Skye A.; Thompson, James
Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling
Climate warming should result in hotter droughts of unprecedented severity in this century. Such droughts have been linked with massive tree mortality, and data suggest that warming interacts with drought to aggravate plant performance. Yet how forests will respond to hotter droughts remains unclear, as does the suite of mechanisms trees use to...Grossiord, Charlotte; Gessler, Arthur; Reed, Sasha C.; Borrego, Isaac; Collins, Adam D.; Dickman, Lee T.; Ryan, Max; Schönbeck, Leonie; Sevanto, Sanna; Vilagroso, Alberto; McDowell, Nate G.
Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination
Background and aimsBiocrusts are communities of cyanobacteria, mosses, and/or lichens found in drylands worldwide. Biocrusts are proposed to enhance soil fertility and productivity, but simultaneously act as a barrier to the invasive grass, Bromus tectorum, in western North America. Both biocrusts and B. tectorum are sensitive to climate change...Ferrenberg, Scott; Faist, Akasha M.; Howell, Armin J.; Reed, Sasha C.
Long-term evolution of sand transport through a river network: Relative influences of a dam versus natural changes in grain size from sand waves
Temporal and spatial nonuniformity in supplies of water and sand in a river network leads to sand transport that is in local disequilibrium with the upstream sand supply. In such river networks, sand is transported downstream as elongating waves in which coupled changes in grain size and transport occur. Depending on the magnitude of each sand‐...Topping, David; Mueller, Erich R.; Schmidt, John C.; Griffiths, Ronald; Dean, David; Grams, Paul E.
Spatially explicit patterns in a dryland's soil respiration and relationships with climate, whole plant photosynthesis and soil fertility
Arid and semiarid ecosystems play a significant role in regulating global carbon cycling, yet our understanding of the controls over the dominant pathways of dryland CO2exchange remains poor. Substantial amounts of dryland soil are not covered by vascular plants and this patchiness in cover has important implications for spatial patterns and...Wertin, Timothy M.; Young, Kristina E.; Reed, Sasha C.
Geomorphometry in landscape ecology: Issues of scale, physiography, and application
Topographic measures are frequently used in a variety of landscape ecology applications, in their simplest form as elevation, slope, and aspect, but increasingly more complex measures are being employed. We explore terrain metric similarity with changes in scale, both grain and extent, and examine how selecting the best measures is sensitive to...Ironside, Kirsten E.; Mattson, David J.; Arundel, Terry; Theimer, Tad; Holton, Brandon; Peters, Michael; Edwards, Thomas C.; Hansen, Jered R.
Key morphological features favor the success of nonnative fish species under reduced turbidity conditions in the lower Colorado River Basin
As a result of anthropomorphic alterations to the lower Colorado River basin and other southwestern rivers, water turbidity has been greatly reduced and introduced, nonnative fishes thrive in these waterways. To quantify key morphological features that may allow nonnative fishes to displace native fishes, we compared eye diameter (a proxy for...Moran, Clinton J.; Ward, David L.; Gibb, Alice C.
Sediment transport and deposition
Sediment transport and deposition (sedimentation) occurs from natural and anthropogenic sources in rivers, lakes, and reservoirs. Substantial changes in sediment transport (such as a major increase or decrease in sediment supply) can impact aquatic ecosystems that depend on a particular sediment quantity and particle size, for example, through...Sankey, Joel B.; East, Amy; Kreitler, Jason R.; Tague, Christina (Naomi)
Species-specific nitrogenase activity in lichen-dominated biological soil crusts from the Colorado Plateau, USA
Background and aimBiological soil crusts (biocrusts) play numerous crucial roles in drylands, which comprise over 40% of Earth’s terrestrial surface. Among these key contributions is the fixation of atmospheric nitrogen. Yet, relatively little is known about the N2 fixation capabilities of different lichen species that are found in late...Torres-Cruz, Terry J.; Howell, Armin J.; Reibold, Robin H.; McHugh, Theresa A.; Eickhoff, Mackenzie A.; Reed, Sasha C.