Desert diversity cut by 'human activities'

Desert shepherd on his camel

Related Stories

Humans may be destabilising desert ecosystems across the world, according to a new study.

Analysis of the human impact on dryland ecosystems suggests it is "drastically changing" mammal communities.

The scientists believe that activities such as overgrazing livestock lie behind increasing local extinctions and a reduction in diversity.

The work will help to inform future conservation efforts, said lead author Ms Maria Veronica Chillo.

The findings are published in the Journal of Arid Environments and assess how man-made disturbances affect the role of mammals in the ecosystem.

"We report for the first time that in drylands, the effect of human-induced disturbances on mammal functional diversity is negative," said Ms Chillo, a biologist in the Biodiversity Research Group at the Argentinian Institute of Arid Lands Research.

Life in a desert

Camels sit in grassy desert

"Regardless [of] the characteristic of the disturbance, functional diversity is diminished."

The review brought together evidence from 25 studies that evaluated the effect of human-caused disturbances on mammals in arid and semi-arid lands.

A total of 110 species were included in the analysis, spanning a range of animals.

Poaching, logging, grazing, fires and introduction of invasive species were some of the ways that humans were found to have damaged mammal communities.

Although deserts and arid lands may seem to be barren places, they often support complex and fragile ecosystems in which mammals play a key role.

Some mammals dig to build nests or find food, which can bring organic material underground, enriching the soil.

Many herbivores play an important role in maintaining plant life by eating leaves and dispersing seeds.

Life in a desert can be a precarious existence for many mammals. They are constantly exposed to extreme and unpredictable environmental conditions and will be negatively impacted by anything that wipes out the resources they rely on, said Ms Chillo.

White-bellied fat-tailed mouse opossum The White-bellied fat-tailed mouse opossum is a desert mammal found in South America that feeds mainly on insects
Patagonian fox This Patagonian fox is a "zorro", one of the false foxes from South America, and native to arid and semi-arid land, particularly in Chile and Argentina
Gray Leaf-eared mouse The Gray Leaf-eared mouse is found across South America and was one of the species recorded by Charles Darwin's expedition to South America
Patagonian mara: Dolichotis patagonum The Patagonian mara resembles a rabbit but is actually a large rodent that breeds in warrens and can be spotted in open ground particularly in Argentina

The "human activities" that the study suggests are most damaging mammals' role in the ecosystem were those that made fundamental changes to habitat type, such as fires or overgrazing that caused grassland to turn into shrubland.

"The most negative effect is seen when disturbances change the conditions of the system [such as something that] modifies the structure or dominant plant species," said Ms Chillo.

The team found that "old fire" from at least a year ago seemed to have a more detrimental effect than "recent fire".

Recent fires simply wipe out plants, whereas new types of vegetation colonise areas scorched by fire that happened earlier. These new plants can be more damaging to desert mammals than no plants at all.

Cars parked at desert camp in sandstorm The threat of sandstorms doesn't prevent humans disturbing desert wildlife

But the team also found that moderate grazing, while it did have a small impact on mammal diversity, had a much more limited effect.

The scientists hope to understand how humans can continue to make use of desert habitats while preserving the mammals' contribution to the ecosystem in areas such as the Monte desert in Argentina.

"The fact that livestock production [one of the main human activities in arid lands] does not represent the most aggressive human activity to mammal functional diversity opens new avenues of research."

The scientists hope that sustainable livestock production is a strategy that might help protect the biodiversity of these areas from human activities in the future.

More on This Story

Related Stories

The BBC is not responsible for the content of external Internet sites

More from nature

  • Cardinal fish and ostracodFish filmed spitting 'fireworks'

    Film crew captures ostracods' spectacular defensive lightshow that makes predatory fish spit them out.

  • Arapaima'Locally extinct'

    A giant fish which used to dominate the Amazon river is now absent in many areas


  • DragonflyRapid reactions

    Dragonfly's super quick reactions recorded in slow motion by BBC film-makers


  • Wingless adult male of the midge Belgica antarcticaExtreme survivor

    Antarctic midge's small genome may be an adaptation to its extreme environment


  • Myotis midastactus specimen (previously identified as Myotis simus)Golden discovery

    A bat from Bolivia is described as a new species by scientists


  • Dinosaurs 'shrank' to become birds

    Huge meat-eating, land-living dinosaurs evolved into birds by constantly shrinking for over 50 million years, new research shows.

  • Would we starve without bees?

    Honey bees are under threat, and as pollination significantly contributes to the food we eat, what would we do without them?

  • Eggshells may act like 'sunblock'

    Birds' eggs show adaptations in pigment concentration and thickness to allow the right amount of sun for embryos, scientists say.

  • Female shrimps are more aggressive

    Female snapping shrimps are more aggressive than males when defending their territories despite their smaller claw size, a study shows.

BBC iWonder

  • Honey bee close-upInsect intelligence

    Are honey bees as smart as your sat nav?

  • Tyrannosaurus rex skull (c) Mark Williamson / Science Photo LibraryDinosaur dynasty

    One group of dinosaurs survived and their descendants can be seen all around us today


  • Brown rat cluse upRise of the rodent

    Reports of giant, 'super rats' are filling the headlines. But why are we being overrun by rats?


  • Cuckoo portraitHoliday hotspot

    What makes the UK such an attractive destination for visiting wildlife?


Awesome! And there's nothing common about such beauty.

Elaine Bernon on Facebook comments on the trio of common blue butterflies in our Photo of the Day.

Things To Do

RUN BY THE BBC AND PARTNERS

More Nature Activities >

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.