Image of the Day: Fragmented Habitat
Image of the Day: Fragmented Habitat

Image of the Day: Fragmented Habitat

Human activities may be affecting both narrow-ranged plants and widespread ones.

Emily Makowski
Dec 17, 2019

ABOVE: A fragmented habitat caused by diverse land use in Zhejiang Province, China

Astudy of 9,701 plant species in China suggests that land use by humans affects the way plants fill in their potential geographic ranges. Researchers led by Keping Ma, an ecologist at the Chinese Academy of Sciences, analyzed distribution data for vascular plant species to calculate range filling, or how much of a potential suitable location certain species take up. They then compared this measurement with human population density and the proportion of cropland in the species’ range areas. Their results were published in PNAS yesterday (December 16). 

The team found that in areas with high levels of human activity, plants with narrow ranges fill up less of their potential space—that is, the individual plants are distributed throughout a smaller area. But for plants that have wide ranges, the opposite is true. Higher levels of human activity are associated with widespread plants taking up more of their range. This may be because many species with narrow ranges are specialized to live in specific environmental conditions, making them more susceptible to environmental disturbances, according to the authors. The results suggest that human activities can result in the replacement of narrow-ranging species with wide-ranging ones, making ecosystems less diverse, the researchers conclude.

Gastrodia elata, a narrow-ranged orchid (left), and Pinus massoniana, a widespread pine tree (right), two species included in the study

W. Xu et al., “Human activities have opposing effects on distributions of narrow-ranged and widespread plant species in China,” PNAS, doi:10.1073/pnas.1911851116, 2019.

Emily Makowski is an intern at The Scientist. Email her at