Humans have a knack for moving plants and animals around.
With human help, over 37,000 species have traveled from their native homes to new parts of the world. Thousands of these “alien” or introduced species have even become invasive in their new environments, harming local biodiversity and human lives. Such invasions are only expected to increase in the future. But there’s hope: areas managed by Indigenous peoples keep weeds at bay, according to a recent study published in Nature Sustainability.
Researchers found this by overlaying maps of Indigenous people’s lands (IPLs) with recently published of millions of alien species from around the world. Their analysis showed that, in general, IPLs have 30% fewer introduced species than comparable natural lands not managed by Indigenous communities.
“I am not surprised by the findings that Indigenous lands have fewer alien species, but seeing extensive, good quality evidence for this on a global scale is very useful,” Priscilla M. Wehi, a conservation biologist at the University of Otago, New Zealand, told Mongabay in an email. Wehi was not involved in the study.
IPLs harbor much of the world’s intact forests and biodiversity. One reason they also have fewer introduced species, the study found, is their location—IPLs tend to be far away from cities and roads, which likely reduces the chance of species entering these areas. In fact, the researchers found that IPLs closer to urban areas and roads usually have higher numbers of introduced species than those located in more remote, less accessible areas.
Areas managed by Indigenous peoples also tend to have more intact forests, less cultivated land, and fewer settlements than other natural areas, the study found. The lower levels of disturbance, the authors write, might help slow down the spread of non-native species.
The way Indigenous peoples manage their areas also likely plays a role, the authors write. The researchers couldn’t investigate this hypothesis in detail because of a lack of data on local Indigenous land management practices. But some studies show that traditional practices, such as those used by Indigenous communities in Australia and India, have historically controlled the spread of invasive species.
However, IPLs aren’t free from introduced plants and animals. In fact, more than 2,300 invasive alien species are found on lands managed or owned by Indigenous peoples, Andy Sheppard, Chief Research Scientist for Biosecurity at CSIRO, Australia’s national science agency, who wasn’t part of the study, said in an email. So, For example, invasive species like Lantana camara in the forests of southern India have reduced visibility for local communities, increasing human-wildlife encounters.
Moreover, IPLs remain under threat from development, mining, and conservation schemes. So, support for Indigenous peoples’ demands for greater rights and autonomy should continue, Jocelyne Sze, a conservation scientist at the Autonomous University of Barcelona, who was not part of the study, said in an email.
Banner image of a Cakchiquel family in the hamlet of Patzutzun, Guatemala, by John Isaac via Flickr (CC BY-NC-ND 2.0)
Credits
