Saturday, August 9, 2008

Trees of Andalucia on threat of global warming

Spanish Fir
Abies Pinsapo

In 1837, during one of his exploratory visits to the south of the Iberian Peninsula, the Swiss Botanist Edmond Boisser discovered a new species of tree: Abies Pinsapo, popularly known as the pinsapo pine or Spanish fir. Pinsapo Grazalema

The tree can grow up to 30m tall and live as long as 200 years. It has tiny needle-like leaves, which are extremely sharp and cylindrical in shape, and although this foliage appears lightweight, it throws out a very dense shade on the ground.

Found only in the southern mountains of Andalucia and in the north of Morocco, botanists discovered that the pinsapo had been around since the Tertiary geological time period - before the Ice Age! How could it have survived?

What probably happened is that the climatic changes occurring during the Pleistocene period were not as intense in Andalucia as might be assumed. In that case, the glaciers of the Ice Age that reached down from the North may have stopped short of these mountains, thus saving the species from extinction.

What the elements couldn't destroy man almost did. At the beginning of the last century, due to extensive cultivation, pinsapo numbers were dwindling. In 1964 there were just 700 hectares of pinsapo forests remaining. Now, thanks to careful forestry management, there are 5000 hectares.

However, just as this distinctive tree looked set to last until the next Ice Age, a new threat has Fungus HeteroBasidium Annosumappeared - the fungus 'heterobasidium annosum'. Invisible but deadly, the fungus attacks the roots, moves up the trunk and finally brings the tree down. Experts consider that changes in the climate (local effects of global warming) have weakened the species' resistance to this fungus, which in normal circumstances would not pose a threat.

So far, the response of the regional government has been to burn infected specimens to prevent the spread of the disease. Ecologists are calling for a seed bank to ensure the survival of the species. In the future pinsapos could then be planted in areas where the effects of global warming have been less noticeable, such as Sierra Nevada and Cazorla.

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