Problem

A Growing Need

Dryland regions cover 40% of Earth’s land surface, host a rich variety of unique plants and animals adapted to aridity and support 44% of the world’s cultivated systems and half of all livestock. One-third of people on Earth live in these areas, too, including the poorest and most marginalized in the world—and these communities are bearing the brunt of climate change right now. 

Climate Change

What does it mean to lose biodiversity?

Loss of biodiversity is also happening among landrace species of plants and animals. Landrace species are animals and plants that lived alongside us and we have used for food and clothing, and consequently have adapted, not for a few decades, but centuries to a specific ecosystem without much human intervention. In our modern society, they are often characterized by low commercial value, and are considered not viable economically, that is their pecuniary sustainability is marginal and their risk of extinction is high.

We are finding landrace species may play a significant role in protecting native ecosystems and our lack of knowledge regarding their relationships with the environment may prevent the design of successful conservation measures. We are changing them faster than we are discovering how they can help us adapt.

Addressing the climate emergency will require not only dramatic reductions in greenhouse gas emissions but also the large-scale removal of CO2 from the atmosphere. Agricultural and natural lands are our most valuable tools in massively scaling up rates of CO2 sequestration across the globe while also building climate resilience and ecological health.

Fragile desert ecosystems are some of the most biodiverse landscapes on the planet. They might have answers to a drying and heating world.

To survive, they require tenacity and remarkable adaptations from their inhabitants. Since desert plants and animals have to survive searing drought, high winds, and intense heat or cold, they've evolved specific strategies for thriving in a harsh environment. Biocrusts, or biological soil crusts, are collections of cyanobacteria, lichens, mosses, and other organisms that cover the fine, sandy soils of arid regions. Collectively, they form layers — crusts — across the desert floor harboring much needed nutrients and moisture for desert plants. Biocrusts essentially hold these desert ecosystems together.

Recent research has found plant health is directly proportional to the beneficial microbe health that exists in the soil. In arid soils, the beneficial microbes are generally in the top centimeter of soil crust. According to a recent estimate, biological soil crusts (biocrusts) currently cover about 12% of Earth's terrestrial surface and about 30% of all dryland soils (Rodriguez‐Caballero et al., 2018a).

Despite their prevalence, biocrusts are imperiled by global change factors, in particular the combined effects of land‐use intensification and climate change, which may cause a strong decrease in bio-crust coverage at local, regional, and global scales. Their disappearance could endanger highly effective carbon sinks present in deserts with abundant grasses and shrubs — like the Southwest deserts. Less biocrust means more erosion, preventing desert plants from growing and absorbing carbon dioxide. Biocrusts stabilize the soil in a big way, and plants and seeds need stable soil to grow, and need protection from erosion. They retain much-needed water and exude natural carbon and nitrogen into the soil, creating a fertile environment for plants to thrive.

Soil scientists are also studying the role of biocrust itself in the carbon cycle, determining whether its colonies sequester carbon dioxide at the same rates as shrubs and grasses. Considering biocrusts cover an estimated 12 percent of the planet’s landmass (twice the amount as tropical rainforests), losing them could have massive effects on the future of carbon reduction. On top of physical disturbances, climate change and hotter weather are hindering biocrusts’ ability to recover from damage. “Not disrupting it is essential to not disrupting these ecosystems,” Young said. “These intact dry places have a lot of a value.”

Where biocrusts have been diminished, native grasses are reacting negatively to worsening, long-term drought conditions. Issues with overuse by livestock and introduced species are further stressing these systems resulting in lower biodiversity, which can have serious impacts on the entire ecosystem.