UH researchers find climate change may reduce coastal grassland plant diversity

Inside this greenhouse on the roof of the University of Houston, plant-soil feedback could lead to a powerful theory for predicting the response of plant communities to changes in precipitation caused by climate change. The key, according to researcher Jan Dudenhoeffer, is not only in wet or dry conditions, but also in the interactions within the soil. The team’s findings have just been published in Nature Ecology and Evolution.

Climate change presents a myriad of challenges, from changing temperatures to rising sea levels and extreme weather events. It could also lead to less plant diversity in coastal Texas grasslands, according to a new study from the University of Houston.

The team of ecology and evolution researchers examined the impact of rainfall on plant-soil interactions. Their findings could help conservationists and agricultural leaders predict what future plant environments will look like under different climatic conditions, and more specifically, how climate change might influence Texas grasslands. the study was published today in Nature Ecology and Evolution.

“If we look at what climate change has in store for us, we will see changes in precipitation and we may end up with different plant communities,” said lead author Jan Dudenhoeffer, postdoctoral researcher in the College of Natural Sciences and Mathematics of the University. ‘uh. “Not just because some plants do better or worse in wet or dry conditions, but because of the interactions that occur in the soil.”

Various plant species grow in different soil communities. Soil communities are bacteria, fungi and other microorganisms that can be beneficial or harmful to plants. This interaction is called plant-soil feedback, and for ecologists it is a powerful theory used to make predictions about plant community development. However, until the publication of this article, no one had used plant-soil feedback to predict how plant communities will respond to changes in precipitation due to climate change.

Dudenhoeffer collaborated on the study with Kerri Crawford, an associate professor of biology and biochemistry, and Noah Luecke, a doctoral student in Crawford’s lab.

The research team tested eight plant species from the Texas coastal grasslands: tuberous milkweed, Bothriochloa ischaemum, Ratibida columniferous, Rudbeckie hirta, Sorghum halepense, Sorghastrum nutans, Schizachyrium scoparius and Verbena brasiliensis.

They grew about 2,300 plants in the greenhouse above UH’s Science and Research Building 2, in one of the largest studies of its kind. Each plant species was grown in soil previously occupied by a plant of its same species or in the soil of a plant of each of the other seven species.

“The size of this experiment and its complex design manipulating precipitation and microbial communities posed logistical challenges,” Luecke said. “The design, configuration, data collection, and molecular and nutritional analysis could not have been accomplished without our cooperative effort.”

They conducted their experiment with three different water treatments – low watering to mimic drier conditions, medium and high watering. They tested plant growth in all combinations of soil and watering levels, then used a computer simulation to predict how a plant community would develop over time, given their results.

They found that plant diversity decreases as conditions become wetter, as certain plant species would become more dominant and could eventually take over an environment.

“If the world becomes wetter, interactions between plants and soil microbes will lead to the loss of plant species from communities,” Crawford said. “It becomes more difficult to predict which species will remain in communities.”

Low plant diversity is often associated with unstable systems. For example, if one species does poorly under certain circumstances, a different species might compensate and thrive in the biome. But if a single species is dominant, and something happens and it’s wiped out, there’s a significant problem because the loss can’t be cushioned by other species, the researchers say.

The team writes that future work would involve further study of the timing of rainfall events on plant-soil interactions and how soil communities of different groups of soil fungi respond to changes in rainfall patterns.

– Story by Rebeca Trejo, UH College of Natural Sciences and Mathematics