Agriculture

Research on plant roots challenges the nature of ecological trade-offs

Certain characteristics of the roots of a plant determine the climatic conditions in which a particular plant predominates. A new study led by the University of Wyoming sheds light on this relationship and casts doubt on the nature of ecological trade-offs.

Daniel Laflin, an associate professor of botanical studies at the University of Washington and director of the Earth Vegetation Project, led the study, including researchers at the German Center for Integrated Biodiversity Studies in Leipzig, Germany. Leipzig University; and research with Wageningen University in Wageningen, the Netherlands.

“We have found that root features can explain the distribution of species throughout the globe. It has never been tried on such a scale,” says Laughlin. “We found that species with thick, dense roots are more likely to occur in warmer climates, while species with thin, less dense roots are more likely to occur in colder climates. This is a nutrient. With mycorrhizal fungi that acquire resources such as and affect the ability to engage in symbiotic relationships. “

Laughlin is the lead author of a treatise entitled “Root traits explain the distribution of plant species along climatic gradients, but challenge the nature of ecological trade-offs” today (June 10). Was announced in. Nature Ecology & EvolutionThis online-only journal publishes monthly the best research from all over ecology and evolutionary biology.

This treatise includes contributors from more than 50 academic, environmental, research institutes, and research institutes.

Plant roots usually remain hidden under the ground, but their role in plant distribution should not be underestimated. Roots are essential for water and nutrient uptake, but little is known about the effects of root traits on species distribution.

To investigate this relationship, an international team of researchers analyzed a root feature database, GRooT, and a vegetation database known as sPlot. Each is the largest database of its kind. This work was facilitated by sDiv, the integrated center of the German Center for Integrated Biodiversity Research. sDiv supports the collaboration of scientists from different countries and disciplines.

Researchers have analyzed the root characteristics of several plants. These include specific root lengths and root diameters, as well as root tissue density and root nitrogen content. The characteristics of these roots were compared to the environmental conditions in which these plants occur. Researchers have found that in forests, species with relatively thick fine roots and high root tissue density are more likely to occur in warmer climates, while species with more delicate, longer fine roots and lower root tissue density have cold climates. I found it to be seen more often in. A classic trade-off.

In contrast, forest species with large diameter roots and high root tissue densities were more commonly associated with arid climate, while species with opposite characteristic values ​​were not associated with humid climate. did. Instead, in warm or humid climates, a variety of root traits occurred.

Laughlin states that this finding is important because roots are literally the basis for plant survival.

“Understanding how root characteristics relate to climate gradients such as water and temperature, how species respond to climate change and change their distribution and how they react. It will be decided, “he says.

Research agenda Ecological trade-offs

Ecology theory builds on trade-offs, and differences in traits between species have evolved as adaptations to different environments. This general view of trade-offs in ecology theory can be widespread in nature. It may have prevented the discovery of sexual one-way benefits. Studies show that identifying the difference between trade-offs and one-way benefits, especially at the species level, will help us understand how individual traits affect community assembly.

However, plants cannot cover all bases. For plants, this means that under certain climatic conditions, lower characteristic values, such as lower specific root lengths, are associated with benefits. Conversely, high characteristic values, such as high specific root lengths, benefit under the opposite conditions.

However, certain root characteristics did not follow this general ecological theory. Rather, certain route characteristics were associated with one-way benefits. Translated, this means that high characteristic values ​​have an advantage under certain environmental conditions, but low characteristic values ​​have no advantage under other conditions.

“We were surprised at how common these one-way benefits are to their roots compared to traditional trade-offs,” says Laughlin.

A typical trade-off is when one species, such as Hakoyanagi, is highly adapted to moist riparian soil but does not adapt to dry conditions and simply withers in dry prairie. In contrast, some dry prairie grasses thrive on dry soils, but can die on moist riparian soils or be overtaken by more productive species along rivers. Laughlin says. This classic idea pervades ecological ideas.

“We found that a set of more subtle traits promoted species outbreaks in dry, cold and harsh climates, but many traits and species were able to withstand warm, moist and mild climates. “In other words, the traits can be beneficial at one end of the climate gradient and neutral at the other end,” he explains.

Alexandra Weigert, a plant ecologist at the University of Leipzig, a member of the German Center for Integrated Biodiversity Research, and the last senior author, said, “This is about how traits promote species distribution. Challenge to understand. Of paper.

The study concludes that this suggests that one-way benefits can be broader than previously thought. One-way benefits are better than warm and moist climates. It was consistently associated with a more extreme cold and dry climate with limited resources. In contrast, studies have shown that warm and humid climates have been associated with greater diversity of root traits.

Laughlin acknowledges that, at least at this time, there is still a lack of extensive empirical evidence to fully challenge the ecological theory of trade-offs. It is an extension of the previous tips on impact.

“We believe our research will help us understand the possible combinations of traits in a particular climatic zone, which is important knowledge for the restoration of ecosystems in a changing world,” said Wageningen University. & Research plant ecologist Rishe Mommer says.

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This study was funded by the German Research Foundation.

https://www.eurekalert.org/pub_releases/2021-06/uow-sop061021.php Research on plant roots challenges the nature of ecological trade-offs

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