Alentejo, Portugal

The cork oak landscapes of Alentejo, the so-called "Montados" are located in Portugal, in an area towards the southeast of Lisbon. This area is one of three major cork oak areas worldwide, besides south- and south-eastern Spain and northern Morocco. Of 8.000 km² of cork oak in all Portugal, the Alentejo region accounts for 7.300 km² of it (Pinto-Correia et al., 2011). In the context of this project we focus on the central Alentejo, and in terms of administrative boundaries on the two municipalities of Montemor-o-Novo and Évora.

Topographically, the Alentejo countryside varies from the open-rolling plains in the south to the granite hills that border Spain in the northeast. The landscape is primarily one of soft rolling hills and plains, with conspicuous shrubs and the native cork oaks and holly/holm oaks.

The Alentejo region lies in the semiarid climate area, highly susceptible to desertification. The average annual rainfall ranges between 400 and 600 mm, distributed over 50 to 75 days, and the average mean temperature is between 15°C and 17,5°C. The further away one gets from the Atlantic Ocean, the hotter and drier the summers are. Some of the hottest areas of Europe are situated in the Alentejo. The most represented soil types are Eutric Lithosols for more than 65% of the area and Ferric Luvisols.

The dominant land use consists of grain crops combined with open oak stands (Quercus ilex L. and Quercus suber L.). Harvested fields are often grazed for the stubble, and on the poorer schist hills, Mediterranean shrubs are dominant (ex. Cistus ladanifer L., Arbutus unedo L.), while plains originally formed from granite are more intensively farmed.

Approximately 41% of the Alentejo landscapes are covered with agroforestry areas dominated by cork oak trees. Livestock farming is very important in the area, mainly cattle (‘Carne alentejana’) and pigs (‘Porco preto’ or ‘Black pork’). Non-irrigated arable land also covers an important proportion of the area.

Montados are human-shaped ecosystems characterized by strong habitat heterogeneity.

The most singular characteristic of the Montados is its savannah-like physiognomy, spread throughout a large-scale mosaic with changing densities of cork (Quercus suber) and holm oak (Quercus ilex rotundifolia) trees.

The patchy vegetation and a strong seasonality of biological plant and animal cycles are characteristic features of this type of landscapes. Consequently, the Montados have long been acknowledged as a land use system with high natural and social values, providing relevant ecosystem and landscape services well beyond the biodiversity conservation.

Culturally, the city of Évora was announced a world heritage site in 1986 and belongs to the network of “Most Ancient European Towns”. Inside, or bordering the two municipalities, three Natura2000 areas are designated, totalling approximately 950 km² of area.

Our study site is located in the Évora district, covering an area of 7.393 km2 with a population of 152.865 inhabitants in 2018, which has decreased since 2011. The population density is very low.

In overall Portugal, average life expectancy had reached 82 years in 2017. The literacy rate is at 99% and 100% of all children get enrolled in primary schools. Alentejo specifically has one of the most aged populations in Portugal and the illiteracy rate among those older than 60 is the highest in the country. The unemployment rate is higher than the national average standing at 7,2% and youth unemployment (<35 years of age) represents 44,6% of all unemployment in the region. This region has the highest inactivity rate in the country (43,9%), as it is home to a large number of pensioners (42,4%). 

The main economic activities in Alentejo are around food, wine, and cork production as well as tourism. In the region, there is an employment rate of 73,4% (317.400 people) from which approximately 12% work in the primary sector, 21% in the secondary sector, and 27 % in the tertiary sector (rest not defined). In terms of regional gross added value, the tertiary sector contributes 63,5%, the secondary sector 27,1%, and the primary sector approximately 9,4% (European Commission, 2019).

Cork production landscapes in the Alentejo are divided into agro-silvopastoral and forest types. At least around 1.000 ha of cork land are under Forest Stewardship Council (FSC) certification since 2005. The Programme for the Endorsement of Forest Certification (PEFC) also offers Non-Timber Forest Products (NTFPs) certification (including cork) in Portugal.

Agro-silvopastoral cork production systems currently cover about 70% of the total cork oak area in Portugal and are found mainly in the province of Alentejo, on flat terrain. They have low tree density (40 to 80 trees/ha), trees are exploited for cork, and the understory is cleared of shrubs for pasture, crops or both. Production activities in the undercover are cereal crops (mainly wheat, barley, and oats) cultivated in long rotations, combined with fallowing, and extensive livestock grazing/raising of cows, sheep, goats, cattle, and the Iberian pig. Associated activities are beekeeping and mushroom picking.

The open tree cover is maintained through natural regeneration and trees are seldom planted. Trees have a direct value as fodder crop, providing acorns and leafy branches in autumn and winter when the herbage production is low; and an indirect value as shelter against cold in winter and heat in summer. Furthermore, the trees create the ecological characteristics that are fundamental to the sustainability of all activities occurring at stand level. Tree density is determined by the need for space for pasture or cereal cultivation in the understory. Land use intensity (grazing and crop production) depends on soil fertility and landholding size.

On smaller properties and where soils are less fertile, grazing is more extensive. When the canopy structure of cork oak agro-silvopastoral systems have a low tree density, the vegetation closely resembles natural savannahs. Mediterranean climatic and soil conditions favour woody rather than herbaceous species, which is why savannahs have always had an anthropogenic origin in the Mediterranean Basin. Agro-silvopastoral systems must be continually maintained through human management by thinning and understory-use through grazing, ploughing and shrub clearing.

Cork oak forests have higher tree density than agro-silvopastoral systems (more than 80–100 trees/ha) and are managed solely for cork production without understory cultivation. When not regularly cleared for fire prevention, the understory contains diverse shrub species (e.g. Arbutus unedo, Erica arborea, Pistacia lentiscus, Populus angustifolia, Lonicera implexa, Ruscus aculeatus). Cork oak forests today cover a small percentage (about 30%) of the total cork oak area in Portugal and are located mainly in the mountain regions of Algarve, hilly areas of Alentejo, and the north of the country, where the soils are shallow and poor.

The area currently occupied by forests results from:

1. agro-silvopastoral land use systems that were abandoned after the rural exodus in the 1960s, where forests recovered naturally, or that were gradually transformed into cork oak forests through artificial cork oak planting;
2. forest areas where understory management was rarely practised because of the difficult (steep) terrain; and
3. new cork oak plantations with high tree densities.