Intensive grazing and soil fertility favour growth of non-native plants

Drivers of non-native plant success in drylands are poorly understood. In a new study of the Leipzig University in Germany, scientists identify the functional differences between dryland native and non-native perennial plants and assess how biotic, abiotic and anthropogenic factors shape the success of the latter.  

Using data from 98 study sites across 25 countries on six continents, the researchers found that non-native plants often grow faster than native species and are particularly successful in areas with intensive grazing and nutrient-rich soils. However, their success is significantly reduced in ecosystems with a high diversity of native plant species.

The success of non-native perennial plants in drylands depends on a variety of factors, according to the scientists who conducted the study. These factors include the local climate, soil quality and the diversity of native vegetation. “Greater biodiversity protects drylands from invasive plants,” says Dr Soroor Rahmanian of Leipzig University and the German Centre for Integrative Biodiversity Research (iDiv). She and Professor Nico Eisenhauer are the joint first authors of the study, which was published in the journal Nature Ecology & Evolution in February.

Drylands cover 45 per cent of the Earth’s surface and are home to 2 billion people

Based on data collected between 2016 and 2019, the team analysed how environmental conditions, plant-animal interactions and human activities combine to shape these drylands. Their focus was on perennial plants, and they examined 41 non-native plant species. These were generally found in small quantities, with only a few species being found particularly frequently in specific areas.

The map shows the dryland regions in the world and the most common non-native plant species in each region.
Source: Rahmanian et al., 2026

Drylands cover approximately 45 per cent of the Earth’s land surface and are home to more than two billion people. Despite their environmental and societal importance, our understanding of how various factors may influence the success of non-native perennial plants in these regions is still developing. “The establishment of these species seems to depend largely on local conditions,” explains Professor Eisenhauer of Leipzig University and iDiv.

“Non-native plants have spread most successfully in heavily grazed areas with nutrient-rich soils. These conditions are often found in less extreme drylands and favour fast-growing species that can tolerate disturbance,” says Dr Rahmanian. The researchers found that higher soil fertility promoted the growth of non-native plants, as did faster decomposition rates and greater fungal diversity.

The researchers further discovered that non-native plants tend to be larger, enabling them to absorb more nutrients from the soil. These traits help them take advantage of the nutrient-rich yet challenging conditions created by grazing.
(Leipzig University /wi)

Reference:
Soroor Rahmanian et al.: "Abiotic and biotic controls of non-native perennial plant success in drylands”, Nature Ecology & Evolution, February 2026