̽��ֱ�� of Cambridge - Wetlands International

Political instability and weak governance lead to loss of species, study finds

fpjl2 — Wed, 20 Dec 2017 18:00:21 +0000

A vast new study of changes in global wildlife over almost three decades has found that low levels of effective national governance are the strongest predictor of declining species numbers – more so than economic growth, climate change or even surges in human population.

̽��ֱ��findings, published in the journal Nature, also show that protected conservation areas do maintain wildlife diversity, but only when situated in countries that are reasonably stable politically with sturdy legal and social structures.

̽��ֱ��research used the fate of waterbird species since 1990 as a bellwether for broad biodiversity trends, as their wetland habitats are among the most diverse as well as the most endangered on Earth.

An international team of scientists and conservation experts led by the ̽��ֱ�� of Cambridge analysed over 2.4 million annual count records of 461 waterbird species across almost 26,000 different survey sites around the world.

̽��ֱ��researchers used this giant dataset to model localised species changes in nations and regions. Results were compared to the Worldwide Governance Indicators, which measure everything from violence rates and rule of law to political corruption, as well as data such as gross domestic product (GDP) and conservation performance.

̽��ֱ��team discovered that waterbird decline was greater in regions of the world where governance is, on average, less effective: such as Western and Central Asia, South America and sub-Saharan Africa.

̽��ֱ��healthiest overall species quotas were seen in continental Europe, although even here the levels of key species were found to have nosedived.

This is the first time that effectiveness of national governance and levels of socio-political stability have been identified as the most significant global indicator of biodiversity and species loss.

“Although the global coverage of protected areas continues to increase, our findings suggest that ineffective governance could undermine the benefits of these biodiversity conservation efforts,” says Cambridge’s Dr Tatsuya Amano, who led the study at the ̽��ֱ��’s Department of Zoology and Centre for the Study of Existential Risk.

“We now know that governance and political stability is a vital consideration when developing future environmental policies and practices.”

For the latest study, Amano worked with Cambridge colleagues as well as researchers from the universities of Bath, UK, and Santa Clara, US, and conservation organisations Wetlands International and the National Audubon Society.

̽��ֱ��lack of global-level data on changes to the natural world limits our understanding of the “biodiversity crisis”, say the study’s authors. However, they say there are advantages to focusing on waterbirds when trying to gauge these patterns.

Waterbirds are a diverse group of animals, from ducks and heron to flamingos and pelicans. Their wetland habitats cover some 1.3 billion hectares of the planet – from coast to freshwater and even highland – and provide crucial “ecosystem services”. Wetlands have also been degraded more than any other form of ecosystem.

In addition, waterbirds have a long history of population monitoring. ̽��ֱ��annual global census run by Wetlands International has involved more than 15,000 volunteers over the last 50 years, and the National Audubon Society’s annual Christmas bird count dates back to 1900.

“Our study shows that waterbird monitoring can provide useful lessons about what we need to do to halt the loss of biodiversity,” said co-author Szabolcs Nagy, Coordinator of the African-Eurasian Waterbird Census at Wetlands International.

Compared to all the “anthropogenic impacts” tested by the researchers, national governance was the most significant. ”Ineffective governance is often associated with lack of environmental enforcement and investment, leading to habitat loss,” says Amano.

̽��ֱ��study also uncovered a relationship between the speed of GDP growth and biodiversity: the faster GDP per capita was growing, the greater the decline in waterbird species.

Diversity on a localised level was worst affected on average in South America, with a 0.95% annual loss equating to a 21% decline across the region over 25 years. Amano was also surprised to find severe species loss across inland areas of western and central Asia.

̽��ֱ��researchers point out that poor water management and dam construction in parts of Asia and South America have caused wetlands to permanently dry out in counties such as Iran and Argentina – even in areas designated as protected.

Impotent hunting regulations can also explain species loss under ineffective governance. “Political instability can weaken legal enforcement, and consequently promote unsuitable, often illegal, killing even in protected areas,” says Amano.

In fact, the researchers found that protected conservation areas simply did not benefit biodiversity if they were located in nations with weak governance.

Recent Cambridge research involving Amano suggests that grassroots initiatives led by local and indigenous groups can be more effective than governments at protecting ecosystems – one possible conservation approach for regions suffering from political instability.

Reference
Amano, T et al. Successful conservation of global waterbird populations depends on effective governance. Nature; 20 December 2017; DOI: 10.1038/nature25139

Big data study of global biodiversity shows ineffective national governance is a better indicator of species decline than any other measure of “anthropogenic impact”. Even protected conservation areas make little difference in countries that struggle with socio-political stability.

We now know that governance and political stability is a vital consideration when developing future environmental policies and practices

Tatsuya Amano

Szabolcs Nagy, Wetlands International

Black-tailed godwit (Limosa limosa), a waterbird with habitats ranging from the Russian far-east to Europe, Africa, and Australasia.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Mangroves could survive sea-level rise if protected

tdk25 — Wed, 31 Jul 2013 07:44:32 +0000

Mangroves, which provide a natural coastal defence to communities around the world, may be able to withstand a future rise in sea levels far more than previously thought, scientists have found.

Their report should serve to allay fears that many mangrove areas could be lost in the coming decades as sea levels go up because of global warming.

It comes, however, with a cautionary note: ̽��ֱ��authors, who have carried out a rare and detailed survey of how mangroves adapt to their environment, also argue that it is vital that they are managed and conserved so that they can continue to provide this protection.

̽��ֱ��survey warns that human activity on land – such as the damming up of rivers or the felling of trees to create shrimp ponds – is currently a far greater threat to many mangrove habitats than the effects of climate change on sea level.

Mangroves – trees and shrubs which grow in saltwater, coastal environments – play a critical role in protecting thousands of shoreline communities in tropical and subtropical regions from floods, storms, and other hazards.

Their densely-packed, overground root systems can absorb wave energy and reduce the velocity of a sudden surge of water. In the 2004 tsunami, for example, mangroves were sometimes the difference between life and death for people whose homes lay in the path of the giant waves which crashed into shorelines around South Asia.

For some time, scientists have been concerned that if sea levels rise as predicted, they will kill off mangroves – removing these natural coastal defences at the very time they are expected to be needed most.

̽��ֱ��new study suggests that this is far less likely than previously thought, however. Dr Anna McIvor, from the ̽��ֱ�� of Cambridge, and the report’s lead author, said: “Although we can expect some mangrove areas to be lost as sea levels rise, many of them appear to be able to withstand it.”

“In fact, changes to mangrove habitats through human activity are likely to pose a bigger threat to these coastal defences than sea level rise as it stands. Our research has enabled us to find out more about how mangroves continue to flourish in spite of a rise in sea levels – but that information should be used as the basis for better management of these important ecosystems.”

̽��ֱ��study was carried out by a team from ̽��ֱ��Nature Conservancy, Wetlands International, and the Cambridge Coastal Research Unit (based in the ̽��ֱ��’s Department of Geography). ̽��ֱ��researchers examined both recent reports looking at surface elevation in mangrove areas, and the historical reasons why mangroves have, in some places, persisted for thousands of years.

They found that the height of the soil surface in mangrove areas is often “surprisingly dynamic”, and in some cases appears to be building up at rates of between one and 10 millimetres every year. ̽��ֱ��global mean sea level rise is currently 3mm per year, meaning that many mangrove areas build up soil at a rate which keeps pace with the sea.

There are several reasons for this, but chief among them appear to be the ability of mangroves to trap sediment as it is carried down to them by rivers, and the work of their roots beneath the surface. “Mangroves provide much of the organic sediment matter that makes up the soil, their complex roots help to bind and trap the sediments on the soil surface, while the unseen growth of roots beneath helps to build up the soil from below,” McIvor said.

Despite this resistance to changes in sea level, however, the report cautions that the future stability of mangroves is by no means guaranteed. “Threshold rates of sea level rise are likely to exist, beyond which mangrove surfaces are no longer able to keep up,” the authors point out.

Perhaps more urgently, in some regions human activities like agriculture and construction are being authorised regardless of their impact on the ecosystems which enable mangroves to thrive.

In some countries, for example, rivers which play a vital role by carrying sediment to the mangrove areas so that the soil can be built up are being dammed or diverted. Another common threat is aquaculture: in Indonesia, and other South Asian countries, mangroves are often cut down without restriction to make way for shrimp ponds.

̽��ֱ��report also warns that mangroves may need room to expand landward, especially where conditions are such that sea level rise may still be a threat to their growth. Communities which rely on them for coastal defence need to leave space to ensure that this can happen, the authors advise.

Dr Mark Spalding, from ̽��ֱ��Nature Conservancy and the Department of Zoology, ̽��ֱ�� of Cambridge, said: “This report shows that well-managed mangroves in many places will continue to support and safeguard many vulnerable communities as sea levels rise. We still have lots to learn about them, but the sensible, precautionary approach is to look after them and restore them as a critical first line of defence.”

̽��ֱ��full report can be downloaded at: http://coastalresilience.org/science/mangroves/surface-elevation-and-sea...

For more information about this story, please contact Tom Kirk, Tel: 01223 332300, thomas.kirk@admin.cam.ac.uk

Human activity is currently a bigger threat to mangroves, and the natural defences they provide against storm surges and other coastal disasters, than rising sea levels, according to a new study.

Although we can expect some mangrove areas to be lost as sea levels rise, many of them appear to be able to withstand it.

Anna McIvor

Wikimedia Commons.

Mangrove trees along a coastline, Everglades National Park.

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