Plants live in tight association with microbes, especially belowground where fungi and bacteria live on and inside the roots of plants. The relationship can be beneficial or harmful to the plant. Some microbes cause plant diseases by decomposing roots. Others trade nutrients with the roots in return for sugars produced aboveground by leaves.
We investigate two main aspects of the relationship between plants and microbes in the soil. First, as it pertains to weeds, we want to know if soil microbes can help or hinder plant invasions. Three highly invasive weeds of contrasting life history strategies; cheatgrass, knapweed and leafy spurge, co-occur with remnants of native plant vegetation. This creates a unique opportunity to observe, characterize, and manipulate interactions between plants and belowground microbial communities. We outline a number of short, intermediate and long-term research projects that will significantly enhance our knowledge regarding plant microbe interactions and soil processes, with the overall goal to better understand, predict and counteract plant invasions, and to restore and manage invaded ecosystems.
Second, we seek to understand how the relationship between plants and soil influences the function of ecosystem processes. Soil microbes are responsible for organic matter decomposition and nutrient cycling between the atmosphere and the land. On this project we collaborate with the Earth Microbiome Project (EMP). The goal is to map and understand the diversity of microorganisms in habitats around the world. We mapped microbial diversity and function across gradients of weed invasions.
Humans have exerted a major influence on plant communities across MPG Ranch that began with fires set by the Native American and continued with intensive livestock grazing, farming, and herbicide applications. The overall result of these activities is that low diversity and low productivity plant communities composed mainly of non-native plants cover many areas. In many cases the existing undesired vegetation is hardy and resistant to replacement, after all it is the stuff that has survived grazing, herbicide applications, and the ranch’s harsh climate. The updates and reports in this section show the approaches we take to figure out the best ways to restore diverse and productive plant communities. The Restoration Map under the maps heading is the best way to explore our restoration work. The map interface allows researchers to explain our methods and research in a chronological and spatial context. Abstracts and links to major updates and plans will be visible on this page.
Rangeland diversification- In some cases we use herbicide applications combined with fire and drill seeding to establish new communities.
Assisted Succession- We have also developed a new approach to restoration of weedy areas using a naturally herbicide resistant initial plant to reclaim weed infestations. The plant is called sainfoin. It is a legume that enriches the soil and allows us to kill-off the weeds seed bank before we re-plant.
Plants constitute the essential core of the ecosystem. Without plants, habitat exists only as an inhospitable void. Knowing that vegetation plays such an integral part in ecosystem function, we keep a close eye on the current state and subsequent changes in vegetation. One facet of vegetation research is vegetation data collection across MPG.
A grid of 560 sampling points covers MPG, with each point separated by about 200 yards. We visit each point to gather data on plant communities. At each point we set up 4 transects, each 50 feet long. Botanists record the plant species encountered at each foot. The reports in this section discuss how we categorize plant communities and the relationships between plant communities and other kinds of organisms.
As we continue to layer data onto this sampling grid we will post new discussions of interactions between plant communities and new groups of organisms. Rebecca Durham, one of the botanists that conducted the original survey, is revisiting many of the points to document lichen and moss community composition.
Nate Gordon's Field Note shared a report on field work, wireless moisture probe testing, and soil sampling.
06-28-13 Restoration Field Note
07-10-13 Field Note