http://www.dailymail.co.uk/sciencetech/article-2332234/Why-rare-species-coral-reefs-tropical-forests-alpine-meadows-determine-planet-survives-global-disasters.html#ixzz2V4REovtx
Researchers from the University of Montpellier in France analysed the role rare species play within coral reefs, tropical forests and alpine meadows
The findings suggest that rare species play a more important part in maintaining ecosystems than was first thought and this ‘calls into question many current strategies’
By Victoria Woollaston
PUBLISHED: 16:03 EST, 28 May 2013 | UPDATED: 16:03 EST, 28 May 2013
Rare species perform unique roles in the way the world functions, claims new research, contradicting what was previously thought.
A study from a team of researchers at the University of Montpellier in France has discovered that rare species perform tasks that more common species can’t.
Using data from three different ecosystems – coral reefs, tropical forests and alpine meadows – the researchers found that these unique functions are essential for maintaining balance within current ecosystems.
Researchers from the University of Montpellier in France have discovered that rare species, such as the giant moray eel, play a much more vital role in the balance of their ecosystems than was first thought.
Rare species, such as the giant moray eel found in coral reefs in the Red Sea, play a much more vital role in the balance of their ecosystems than was first thought
WHAT MAKES UP CORAL REEFS?
Coral reefs are underwater structures made from calcium carbonate released by corals.
Reefs grow best in warm, shallow, clear, sunny and agitated waters.
Often called ‘rainforests of the sea’, coral reefs form some of the most diverse ecosystems on Earth.
They take up less than 0.1% of the world’s ocean surface, yet are home to 25% of all marine species, including fish, mollusks, worms, crustaceans, echinoderms and sponges.
The annual global economic value of coral reefs was estimated at US$ 375 billion in 2002.
However, coral reefs are fragile ecosystems because they are very sensitive to water temperature.
And if these rare species disappear, our ecosystems could fail – or struggle to rebuild in the event of a global disaster.
Lead researcher Dr David Mouillot said: ‘These unique features are irreplaceable, as they could be important for the functioning of ecosystems if there is major environmental change.’
As rare species and the biodiversity of these regions decline, the unique traits and features these animals bring to the areas are vulnerable to extinction because rare species are likely to disappear first.
Biodiverse environments are known by their large number of rare species.
These rare species contribute to the diversity of an area but, up until now, their functional importance within these ecosystems has been largely unknown.
Because there are fewer rare species within a region, they were traditionally thought to have little bearing on how other species interact and how the ecosystem functions, compared with more common species.
If rare species seen in places such as coral reefs and rainforests die out, the carefully balanced ecosystems of those regions could fail and be damaged.
If rare species seen in places such as coral reefs and rainforests die out, the carefully balanced ecosystems of those regions could fail or be damaged. This is because rare species perform unique functions within these areas, say the researchers
The rare pyramidal saxifrage, an alpine plant, is an important resource for pollinators in the mountain regions of Europe
The rare pyramidal saxifrage, an alpine plant, is an important resource for pollinators in the mountain regions of Europe
It was previously assumed that rare species play the same roles within an ecosystem as their common neighbours, yet have less impact because of their low numbers.
This phenomenon is known as ‘functional redundancy’.
The redundancy suggests that rare species merely serve as an ‘insurance’ policy for the ecosystem, in the event of an ecological loss.
To test this, the researchers analysed the extent to which rarer species in the three different ecosystems performed the same ecological functions as the most common ones.
They examined biological and bio-geographical information from 846 reef fish, 2,979 alpine plants and 662 tropical trees and found that most of the unique and vulnerable functions, carried out via a combination of traits, were associated with rare species.
Examples of rare species that were found by the researchers to perform vulnerable functions include the giant moray, a predatory fish that hunts at night in the labyrinths of coral reefs and the pyramidal saxifrage, an alpine plant that is an important resource for pollinators.
Another was the Pouteria maxima, a huge tree in the rainforest of Guyana, which is particularly resilient to fire and drought.
Not only are these species rare, they also have few functional equivalents among the more common species in their respective ecosystems, according to the research published in the journal PLOS Biology.
The Kaieteur National Park in Guyana.
The Kaieteur National Park in Guyana. The rainforest in Guyana is a biodiverse environment because of the large number of species that live in relatively close proximity. Researchers have found that rare species, including the Guyanan tree Pouteria maxima, are fundamental to maintaining balance in biodiverse ecosystems
Dr Mouillot said: ‘Our results suggest that the loss of these species could heavily impact upon the functioning of their ecosystems.
‘This calls into question many current conservation strategies.’
The work emphasises the importance of the conservation of rare species, even in diverse ecosystems.
Dr Mouillot said rare species are more vulnerable and serve irreplaceable functions, the preservation of biodiversity as a whole – not just the most common species, but all those who perform vulnerable functions – appears to be crucial for the resilience of ecosystems.
He added: ‘Rare species are not just an ecological insurance – they perform additional ecological functions that could be important during rapid transitions experienced by ecosystems.
‘The vulnerability of these functions, in particular biodiversity loss caused by climate change, highlights the underestimated role of rare species in the functioning and resilience of ecosystems.
‘Our results call for new experiments to explicitly test the influence of species rarity and the uniqueness of combinations of traits on ecological processes.’
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