A tiny wonder adaptive

A century ago, was already quite low, but maintained a sufficient number of individuals who inhabited the north face of the rocks and terraces of the Tramuntana mountains of Mallorca Island. Nothing presaged that in the early twenty-first century descendants could be counted on the fingers of one hand or one and a half. I'm talking about the beautiful fern Asplenium fontanum, in the last hundred years has endured two such brutal assaults that have taken him to the brink of extinction.

Asplenium fontanum in June after spring bud break. Later this issue was grazed by a goat. He has been on the verge of death.

One of them the perpetrators of the Spanish and foreign botanists middle of last century with its notorious penchant for collecting whole plants to enrich their private herbaria. Was not enough to save a worksheet, a frond, a branch or a pair of flowers and fruits. Nor does it matter if the plant was very low. Conservationist sentiment did not exist. They were not aware that they are putting on the brink of extinction Asplenium fontanum and many other plants, some of them extremely rare endemic to Balearic Islands.

Then came the plague of feral goats, which in recent decades have proliferated, they are forced to eat in times of plenty would not have eaten, or eat it all, because their stomachs can digest it all, including small and leathery patch ferns, including Asplenium fontanum, more predation suffered by having fronds much more tender and juicy than other ferns.

Metal cage nailed to the wall of a terrace of two technicians from the Department of the Environment of the Balearic Government to protect the last remaining Asplenium fontanum on the island of Mallorca. The copy-protected this cage was grazed by a goat that ate all the fronds, but managed to overcome and sprout again. With this protection goats can no longer do the most damage.

Each cage has a data plate metal like this with a phone to notify in case someone finds it broken or torn.

Authentic Mallorcan wild goat, native to the eastern Mediterranean, which has several thousand on the island following its introduction by the first settlers, has also been hurt by this invasion of feral domestic goats, which, in addition to competing for food, is have hybridized with the wild, making them lose the purity of their ancient race.

But here nature wise she went to work to solve the problem before it was too late and managed to save the genes of Asplenium fontanum, even at the expense of their near extinction.

Asplenium petrarchae ssp. bivalens fronds in May with the new spring

The hybridization solution was also another very rare fern, Asplenium petrarchae ssp. bivalens, whose union came a tiny hybrid son, the Asplenium majoricum, which brought in its genome everything that is good for both parents, especially the small size of Asplenium petrarchae ssp. bivalens, allowing you to go virtually unnoticed, protected from the stones of the terraces of the hungry mouth of the goats and the resistance to long or hot dry summer months Mallorca, during which, like their parents, entering aestivation, its fronds are dehydrated, rolled, dried up and pretend to be dead and lasts for three, four and up to 5 months.

 

Asplenium majoricum in early fall, after rehydration. Three days before his appearance was deplorable and looked dead. Specimen photographed in the gully of Biniaraix.

In last autumn usually fairly heavy rain and 24 hours after the first rain comes the miracle, I would say the revival, as their fronds brown, twisted and rehydrate parched, leafing, unroll, spread and show a fresh and turgid with a vibrant bright green, as if nothing had happened. The aestivation of small ferns Aspleniaceae family is an adaptation to the Mediterranean summers only between plants, allowing them to survive long periods of drought.

 

Asplenium majoricum in the gully of the municipality of Sóller Biniarix autumn sprouting new fronds.

Asplenium majoricum, being an allotetraploid interspecific hybrid with two different complete genomes and not combined at its core, should theoretically be sterile. However he has overcome the barrier of sterility in their spores by combining the exact middle of the genome of his father and half of the genome of their mother, with all the genes necessary for life, producing fertile diplosporas, which enabled it to colonize great success and booming all habitats own parents, with a clear competition with them. I would say is a champion of survival.

Asplenium majoricum group in April in the wild, growing on a substrate of moss between the stones of a wall patch. He is accompanied by copies of Sedum dasyphyllum. (Double click on the photo to enlarge)

Sori on the underside of the pinnae in March. Note the small size of the ferns in relation to the thumb nail.

However, the nature, so ingenious, through the creation of a new fertile species hybrid, has managed to preserve from extinction the genes of two species of ferns that are currently in dramatic regression in the island.

 

Diplospores of Asplenium majoricum, much larger than their two parents.

Asplenium majoricum was first described in the Valley of Soller in 1911. For several decades it was considered endemic to Mallorca, until it was found in the recent Valencia and southern Catalonia. However, according to studies of genetic markers, Asplenium majoricum of Mallorca and  the copies of Valencia and Catalonia are not related and are thought to have a hybrid independent origin.