General description of Baixo Guadiana SES

Authors:	Michiel Curfs, Anton Imeson
Editors:	Alexandros Kandelapas, Vassilis Koutsoukos, Jane Brandt

Editor's note 11Mar13: Source D331-3.3

Location

The Baixo Guadiana study area lies in the lower Guadiana Basin, situated at the south western part of Iberia along the border between Spain and Portugal. The total size of the study area is 2,612 km².

Climate

Climate is typical Mediterranean with hot and dry summers and a wet winter period. Almost all precipitation (avg. 500 mm/year) falls between November and March. Rainfall records (1931 – 1997) show a declining trend in the total amount. The evapotranspiration is estimated at approximately 900 mm/year and the aridity index is 0.55.

Geology, soils and hydrology

The study area is of carboniferous origin consisting of shale, slates and greywackes of a fluvial origin. The communities Sanlúcar de Guadiana and Alcoutim are also situated on carboniferous material but of volcanic origin (Tuff, lavas, acid breccias, quartz). Younger formations from the Quaternary, consisting of conglomerates, gravel and red clay, are also present. The area is best described sloping land; a dissected low to medium level undulating to rolling landscape. The main group consists of an undulating slope relief on metamorphic material.

Main soils in the area are, Leptosol, Regosol and Cambisol. Soils are generally shallow, with low nutrients and organic matter content. The parent material is divided into three main divisions: flysh (north), shale (central) and conglomerates (south). Soil erosion levels vary. Soil texture is clay loam and sandy loam. Soil depths are generally class 3, with low permeability favouring surface runoff.

The Hydrological network is a complex dendritic river network consisting of well-incised gullies with a high seasonal and torrential regime, with high erosive capacity. The dams in the area are the Andévalo and the Chança on the Spanish side and the Odeleite and the Alqueva in Portugal which the biggest reservoir of western Europe.

Ecosystems and land use

Major ecosystems in the area are Forest, Sub humid semi arid dryland, Cultivated, Urban. The area includes several protected areas: natural parks of higher and lower order, natural reserves and 12 areas falling under the NATURA 2000 network. The estuary of the Guadiana has been declared a RAMSAR site.

Land use change has affected 35% of the area between 1990 and 2006, due to increases forest cover, urban areas and water surfaces (newly constructed reservoirs).

Population, employment and infrastructure

Total population in the study area in 2008 was around 59,000 with only the coastal municipalities Ayamonte (Spain) and Vila Real de Santo Antonio (Portugal) witnessing increases. Average population density is 22 inhabitants/km², ranging from 6 in the mainland to 300 on the coast. Communities in the area are depicted have age indices in the range of 100% - 300%. The population growth is generally positive but is more related to migration rather than natural growth.

Sectoral employment within the communities of the Baixo Guadiana is highest in the service sector (over 60%), except for the municipality San Silvestre de Guzman where agriculture remains dominant. The drop in agricultural employment is dramatic: from 60% in 1900 60.4% to 6% in 2001 and 15.1% active in services. Most farms are owned and managed privately. Unemployment exceeds 23%.

The area has a low density road network and very few schools and medical clinics in the rural inland part of the study area. Huelva province has two hospitals.

Administration and policies in effect

Governance in the study area differs between the two countries. Spanish communites are under the Huelva province, of the Autonomous region of Andalucia. Portuguese communities are under the sub-provinces of the province Alentejo and Algarve.

Assessing LEDD and related policies, in the Baixo Guadiana study area is not without difficulties: Spain and Portugal have different methods, categories and indicators for land assessment. However, several trans-boundary projects as well as arrangements for water management present considerable potential for cross-border collaboration, as does tourism.

In the Baixo Alentejo, the northern part of the Portuguese side of the study site, dramatic changes in land use and rural landscapes are taking place, directly related to the Common Agricultural Policy (CAP), particularly financial support provides for forest plantations. Although forestation may be positive response to LEDD, the practical application of these policies often exacerbates LEDD problems. For example in order to receive EARDF support for afforestation of agricultural land, land clearing has been mandatory, even where vegetation was recovering. Forestation has also included heavy soil mobilisation, compaction, inadequate planting techniques, unsuitable species with no natural regeneration and high densities increasing fire risk, all contributing to LEDD problems

Other relevant policies on the Portuguese side include the rural development programme, PAMAF, and PROT, the regional development programmes of the Alentejo and the Algarve. The PROT also include direct references to forest management and combating desertification, as foreseen in Portugal's National Action Plan.

On the Spanish side, the 'Desarollo Rural de Andalucia 2007-2013 (PDR) (development of rural Andalucia), is also affecting the area, particularly through measure 216 "support to non productive inversions" in order to protect farmland from wind and reduce erosion. Andalucia has also put in place a regional Forest Management Plan (2008-2015)

Both countries have forest fire policies, although they tend to focus on mitigation and post-fire management rather than proactive prevention. Study site provinces are preparing land-use plans, which are at various stages of approval.

Particular LEDD issues in Baixo Guadiana

The main LEDD problems are:

• Forest productivity decline, affecting not only wood production but also Non-wood forest products (cork, gum, medicinal and aromatic plants, fodder, nuts, fruit, truffles) as well as tourism and recreational uses, including hunting.
• Loss of biodiversity, through fires, fragmentation and soil deterioration. In addition, loss of biodiversity in dehesa and montado systems particularly affects the Spanish imperial eagle (Aquila adalberti) and the Iberian Lynx (Lynx pardinus)
• Forest fragmentation cause by infrastructure development (transportation), agriculture and urbanisation. The road network of Spain and Portugal has increased in length by 640% over the past 20 years. Soil sealing is in Portugal has increased by 10% since 2010, while in Spain it has reached dramatic proportions: in the past decade, Spain urban space has expanded more than in Germany, France and Italy combined.
• Soil erosion, deterioration, land degradation and desertification. Dehesa and montado forests protect the soil wind and solar radiation (shadow and windblocks) and also facilitate the condensation of fog (natural fog harvesting effect). They also have very efficient nutrient cycling through deep root systems, leaf litter and manure via agroforestry practices. Nevertheless, as soils are generally shallow, ploughing between trees (twice per year) causes accelerated erosion and land degradation. On the Spanish side, landowners are held responsible for fires starting on their land, preventative ploughing is therefore widely practiced.
• Water stress and phytosanitary deterioration of forest cover. Prevalent pests include Phytophtora spp. affecting all Quercus species and in particular cork and holm oak. This process is called ´seca´ in Spain. Endemic water stress is rendered more severe by human modifications of the hydrological regime: water shortage is now a 'structural characteristic' of the system. Future climate changes are expected to amplify existing water stress.
• Agriculture/ Grazing. The extension of agricultural lands, logging and the practice of burning land are drivers that lead to the degradation and loss, particularly of dehesas and montados. Although clearing of holm and cork oak is strictly fobidded in Portugal Deforestation still occurs to clear land for cultivation and pasture. Clearing of holm oak and cork oak trees (Quercus ilex and Q. suber) is strictly forbidden by law (DIS4ME, Roxo & Casimiro 2004).
  The increase in the number of cows in the Portuguese side, and to lesser extent the Spanish side, has been supported through the CAP subsidies and has contributed greatly to soil erosion. Fragile soils cannot withstand the impact of trampling by cows, where pigs, sheep and goats were traditionally raised, causing both compaction and erosion. Subsidy rates also ignore optimum stocking density of the land, fodder production capability and the water balance, so overgrazing is an inherent problem.
  Pastoral activity is also a major source of wildfires as shepherd use fire regularly to renovate pastures. Pastoral activity was found to be responsible for 20% of all wildfires and for 11% of the total area burned (78% shrublands, 18% forests.
  It is important to note that the mixed agro-silvo-pastoral system of the dehesa and the montado is not a LEDD driver. On the contrary, livestock grazing and to a lesser degree agricultural practice, combined with the maintenance of oak and cork trees provide the system with versatility and long term sustainability. The system does not try to maximise the output of any particular product and also avoids arable farming which is inhibited by both climate and soil fertility. Although economic profitability is limited, sustainability is demonstrated by the longevity of the system. Nevertheless, the system does face threats such as abandonment, air pollution and pathogens.
• Mining. The Iberian Pyrite Belt, touching the northern part of the Huelva province, is one of the most important volcanogenic massive sulphide ore deposits in the world. Although mining has generally declined, mining activity has led to environmental pollution (acid mine drainage, heavy metal soil contamination). In the past, the mines were also a driver of deforestation
• Climate change. Spanish and Portuguese forest ecosystems are expected to suffer form warmer, drier climate, likely to cause more fires and desertification. The trend of declining precipitation is expected to continue, as is amplification of water stress and subsequent conflict. Tree mortality and land degradation are also expected
• Forest Fires
• Tourism and Urbanisation

Responses to LEDD in Baixo Guadiana

Several Responses to LEDD have been developed in the study area. They include:

• Extensive afforestation
• Cross-border cooperation, including infrastructure (e.g. river bridges) and water use awareness raising
• Forest fire management

In order to address fragmentation, Portugal has taken steps to create ecological corridors or green bands. Efforts are being made to extend them across the river to Spain.

Socio-economic decline is addressed through several national and regional economic instruments which as a rule take into account the need to address land degradation, such as

• The Spanish Plan to stimulate the economy and labour, which includes "Silvicultural treatments and improvement of habitats in Andevalo and Chanza" and "Landscaping adjustment of the nuclei of the Andevalo environment"
• EARDF measures
• The "Land use plan of Andalucia" and general urban plans

 

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