Researchers at the University of Granada (UGR) have studied the natural history and conservation status in Spain of the only known population of Polygala balansae in Europe, a thorny bush that can grow up to 1.5 metres high, which was previously thought to be exclusive to Morocco. The team of scientists is calling for it to be protected and included on the list of threatened species.
In 2006, a research team from the University of Granada (UGR) embarked upon a detailed study of the bush Polygala balansae in Spain. The scientists studied its distribution area, the number of individual plants and some features of its reproductive biology. The bush was declared to be a new species in Europe in the same year.
"Field sampling led to us finding only one population, despite searching a much larger area", Juan Lorite, lead author and a researcher at the Department of Botany of the UGR, tells SINC.
The study, which was published last month in the journal Annales Botanici Fennici, counted 246 reproductive individuals. "These data, along with its small area of occupation and potential threats to its population, have led to the species being evaluated as in critical danger of extinction at regional level by the International Union for Conservation of Nature (UICN)", explains Lorite.
The only population in Spain occupies "just" 1,920 m2 near Almuñécar (Granada), at an altitude of 120-160 metres above sea level. This population occupies "a small area of Mediterranean scrubland, in an environment populated by subtropical crops (avocados and custard apples)", the researcher adds.
Some of the threats facing the bush include habitat fragmentation, changing soil use, human settlement encroachment and the expansion of subtropical crops, housing developments, natural or deliberately set fires, as well as biological problems resulting from the low number of reproductive individuals in the population.
The researcher says, "the species itself is not protected and nor is the area it occupies, meaning it should be included in future red lists of threatened species, and protective regulations introduced to cover the whole area where it is found".
The researchers are also calling for urgent measures to protect areas where the bush could potentially grow, and where no protective guarantees are in place, such as Murcia, Almería, Granada and Malaga.
The voyage of the African bush
Prior to this study, the distribution area of Polygala balansae was thought to be limited exclusively to Morocco. The bush can be found in the High Atlas, the Western Anti-Atlas and in some parts of the Mid Atlas. It is very widely distributed in Morocco, where populations have a high number of individuals "and so it is not under threat there", Lorite concludes.
Lorite, Juan; Penas, Julio; Benito, Blas; Cañadas, Eva; Valle, Francisco. "Conservation status of the first known population of Polygala balansae in Europe" Annales Botanici Fennici 47(1): 45-50, 10 de marzo de 2010.