Nature protection and biodiversity - Why care? (Portugal)

For the last 50 years, significant changes have been taking place in Portugal’s ecosystems, driven by profound socio-economic changes. The economy has grown six fold, the number of farmers has decreased by over 60 % and agricultural land has been reduced by 40 %. There has been an intensification of farming alongside a growing tendency towards eucalyptus monoculture which has had negative impacts on biodiversity and ecosystems. Rivers have been dramatically affected by the construction of dams and the increase in pollution from agriculture, industry and settlements. Invasive species have exerted pressure on coastal ecosystems and caused even more damage on the islands. Meanwhile, other species have been overexploited by hunting and fishing (MEA, 2004).

Portugal’s mainland has a climate influenced by the Mediterranean, with dry, hot summers and rainy winters, but it is also influenced by a temperate macroclimate, which results in considerable climatic variation (Miranda, 2002 in MEA, 2004). There is also a considerable diversity of soil materials (Silva, 1982 in MEA, 2004) which, associated with the variation in climate, leads to a wide assortment of soil types (Cardoso, 1973 in MEA, 2004) and ecosystems.

Portugal’s strong biological diversity is explained by its location, which encompasses three bio-geographical regions – the Atlantic and Mediterranean on the Portuguese continent and Macaronesia for the archipelagos of Madeira and the Azores. The combination of its pedology, particular geophysical characteristics and human intervention have given rise to a huge variety of biotopes and ecosystems, housing a wide diversity of species with multiple genotypes. On the other hand, Mediterranean agriculture dating back thousands of years has created a set of human habitats with a high conservation value (MA, 1994 in MEA, 2004). Several species depend on the conservation of these habitats for their survival. Examples of such habitats are the “montado” (traditionally grazed oak forests), the cereal steppes and the mountain “lameiros” (humid meadows) (MEA, 2004).

Portugal is also one of the European Mediterranean countries where desertification has the highest environmental risk (Sequeira, 1998a, b, c in MEA, 2004), particularly in connection with soil degradation caused by water erosion (Giordano, 1992 in MEA, 2004) and the degradation of surface and underground waters (GCID, 1998 in MEA, 2004). Portuguese ecosystems and agriculture are also particularly vulnerable to climate change (Santos et al., 2002 in MEA, 2004) due to the associated risks of fire and drought.

In conclusion, Portugal is one of the European countries with the highest diversity of organisms and farming systems which, at the same time, is most at risk of losing this diversity (MEA, 2004).

References

• MEA (2004). Pereira, H.M, T. Domingos, and L. Vicente (editors). Portugal Millennium Ecosystem Assessment: State of the Assessment Report. Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa.