Biodiversity hotspot vegetation in decline

May 9, 2016 by Samille Mitchell, Sciencenetwork Wa

Vegetation growth in forests and shrublands of WA's global biodiversity hotspot are showing alarming declines, according to a recent study which found a quarter of the hotspot's woody vegetation had disappeared in the past 16 years.

The research also suggests we should expect the trend to continue into the future, which is likely to spell bad news for the local fauna.

The study, involving satellite imagery from 2000 to 2011, shows a fast declining rate of in forest and shrubland across the hotspot.

The hotspot stretches from Shark Bay in the Gascoyne to beyond Esperance in the south-east and to the south-west corner.

It is one of only 34 hotspots around the world— that are under threat and recognised for their incredible biodiversity and for homing plant and animal life that occurs nowhere else on the globe.

The Murdoch University research showed that 15 per cent of the across the hotspot study area (about 37,000 km2)—an area more than half the size of Tasmania—lost a quarter of its vegetation growth between 2000 and 2011.

Further study from 2011 to now indicates the trend is worsening.

Most of the observed declines are due to ever-decreasing rainfall figures across the region, Murdoch University research fellow Niels Brouwers says.

Bureau of Meteorology figures show average rainfall in the area has decreased from 5mm to 40mm every 10 years since 1970.

"There has been a persistent drop in rainfall over the past 40 to 50 years and more and more we're seeing the response to this in declines in forest health," Dr Brouwers says.

While there has been evidence of vegetation health declining at a local scale, this is the first study to examine the entire biodiversity hotspot.

Dr Brouwers drew his conclusions by examining time series , which detects changes in vegetation cover and productivity.

He found the declines were worst in the north-west and south-east transition zones from tree to shrub vegetation.

He says with fewer trees, less carbon is absorbed from the atmosphere and with the persistent declines in rainfall this means the area is becoming increasingly less suited for tree planting efforts as a means of combating climate change.

"Fauna that is dependent of forest habitat, like the threatened Carnaby's Black Cockatoo [Calyptorhynchus latirostris], will also suffer," he says.

"Basically the area covered by forest is getting smaller, and we should prepare ourselves for massive changes in terms of the vegetation we have," he says.

Explore further: Climate change is killing our trees

More information: Niels Christiaan Brouwers et al. Decreasing Net Primary Production in forest and shrub vegetation across southwest Australia, Ecological Indicators (2016). DOI: 10.1016/j.ecolind.2016.01.010

Related Stories

Good luck and the Chinese reverse global forest loss

March 30, 2015

Analysis of 20 years of satellite data has revealed the total amount of vegetation globally has increased by almost 4 billion tonnes of carbon since 2003. This is despite ongoing large-scale deforestation in the tropics.

Scientists dance around Pilbara's fairy circles

April 20, 2016

An extremely rare phenomenon known as fairy circles—a concept more at home in the pages of fantasy books—have sprung into the vast, arid expanse of the modern day Pilbara.

Cockatoos find food in rehabilitated forest

September 24, 2013

Murdoch University researchers have found that Western Australia's iconic black cockatoos have been drawn to a new food source – rehabilitated mining pits.

Recommended for you

Experiments call origin of Earth's iron into question

February 21, 2017

New research from The University of Texas at Austin reveals that the Earth's unique iron composition isn't linked to the formation of the planet's core, calling into question a prevailing theory about the events that shaped ...

Impacts of mass coral die-off on Indian Ocean reefs revealed

February 21, 2017

Warming seawaters, caused by climate change and extreme climatic events, threaten the stability of tropical coral reefs, with potentially devastating implications for many reef species and the human communities that reefs ...

Study finds 6,600 spills from fracking in just four states

February 21, 2017

Each year, 2 to 16 percent of hydraulically fractured oil and gas wells spill hydrocarbons, chemical-laden water, hydraulic fracturing fluids and other substances, according to a new study.The analysis, which appears Feb. ...

Selenium deficiency promoted by climate change

February 20, 2017

Selenium is an essential micronutrient obtained from dietary sources such as cereals. The selenium content of foodstuffs largely depends on concentrations in the soil: previous studies have shown that low selenium concentrations ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.