DeADWeb
Welcome to DeADWeb!
DEcomposition Across Drylands (DeAD) is a collaborative research project funded by the US National Science Foundation through the Macrosystems Biology - NEON Enabled Science program. The project runs 2024-2029.
Why Drylands?
Drylands (arid and semi-arid ecosystems) cover nearly half the world’s land surface. One in three people and over half the global livestock population live in these critical systems. Drylands also play a dominant role in the global cycling of nutrients and carbon. However, our understanding of how nutrients and carbon cycle in drylands is limited relative to mesic (wet) systems.
Decomposition
Plants get most of their nutrients through recycling by taking up nutrients that are released when dead material decays. The decomposition of dead plant material, such as leaves and branches, is thus a foundational biological process that drives the availability of nutrients to plants and the cycling of carbon between the biosphere and the atmosphere.
Scientific understanding of decomposition in drylands lags behind that of mesic ecosystems. One way that dryland decomposition may be different from mesic systems is that litter tends to be relatively evenly distributed in mesic systems but is concentrated in certain areas (e.g., under shrubs or next to rocks) in drylands.
Dryland decomposition is affected by mechanisms that are particularly important to these systems, such as solar radiation and short bursts of moisture availability. We hypothesize that variation in environmental conditions play an important role in regulating decomposition.
Differences between mesic and dryland decomposition are illustrated below. The surface litter distribution, moisture (raindrop), temperature (sun), and temperature are fairly even in the mesic site. As a result, microbes that decompose litter are evenly distributed. In the dryland example, the heterogeneously distributed vegetation and rocks alter the microclimate and microbes, likely altering decomposition patterns.
Our Approach
Collaborative Research
DeAD is characterizing dryland decomposition from small to large spatial scales, with the goal of improving our ability to predict nutrient and carbon cycling through time and space in North American drylands. The DeAD project is deeply collaborative, bringing together experts from a variety of disciplines to address how carbon moves through drylands.
Image credit: Throop et al. 2025 Functional Ecology
This project scales from the microbial to continental scale to increase our understanding of dryland decomposition.
In the field, we are characterizing litter distribution, the micro-environmental conditions where litter accumulates, and litter decomposition rates among locations.
In the lab, we measure decomposition activity under controlled environment conditions.
We connect field data with satellite imagery to understand decomposition pools and processes at larger scales.
We use data to develop models that predict decomposition rates across drylands and explore how decomposition may change in the future.
Education
DeAD is supporting several educational initiatives, including a course module where art and science majors collaborate to develop skills for visual communication of the importance of drylands decomposition and other scientific ideas. We are expanding an educational outreach platform, the Interactive Model of Leaf Decomposition, to encompass drylands. Finally, the project provides cross-disciplinary career development opportunities for undergraduate, graduate, and postdoctoral scientists.
Broader Context
Drylands support billions of people and represent large unknowns in forecasts of future carbon cycling and climate. DeAD will advance the understanding of ecological processes in drylands, critical for informing land management decisions in the face of environmental change.
Where We Work
Collaborating Institutions
Research Sites
Our work takes place at the National Ecological Observatory Network’s four dryland sites.
Santa Rita Experimental Range is in the Sonoran Desert in southern Arizona. This semi-arid site is characterized by hot summers, mild winters, and bimodal precipitation distribution as summer monsoons and winter rains. The mean annual precipitation (MAP) is 346 mm and mean annual temperature (MAT) is 19.3C. The vegetation is primarily a mesquite savanna, with patches of creosote bush scrubland at the lowest elevations.
Jornada Experimental Range is in the Chihuahuan Desert in southern New Mexico. This arid site is characterized by hot summers and cool winters, with precipitation primarily as summer rains. MAP is 271 mm and MAT is 15.7C. Dominant vegetation is desert grassland and mesquite duneland.
Moab NEON Site is on the Colorado Plateau in southern Utah. This arid site is characterized by warm summers and cool winters. Precipitation is primarily during the winter. MAP is 319 mm and MAT is 10.1C. Vegetation includes saltbush shrubland and pinyon-juniper savanna.
Onaqui NEON Site is in the Great Basin Desert in northern Utah. This semi-arid site has warm summers and cold winters. Precipitation is primarily in the winter, much of which is snow. MAP is 288 mm and MAT is 9.0C. Vegetation includes sagebrush shrublands and western juniper savanna.
Funding
Contact Us
For general inquiries about DeAD, contact DeAD PI Heather Throop (heather.throop at asu.edu).
Find contact information for the DeAD Team here.