Characteristics

Characteristics of forests & shrubland: general

2012-06-14T14:24:25+00:00

Authors: Agostino Ferrara, Guiseppe Mancino, Luca Salvati

{xtypo_alert}Editor's note: Text extracted from D311-2.1{/xtypo_alert}

Forests ecosystems and shrublands represent one of the most important terrestrial biomes in terms of distribution and also in terms of goods, services and benefits they provide to humankind. Forest ecosystem services derive directly or indirectly from a wide range of functions related to the biogeochemical processes and physical properties of forest and shrubland systems (FAO 2010a). Increasing demand for forest resources generated by socio-economic development includes not only energy and wood demand, but also land for agriculture and grazing. As a result, forest resources are often overexploited and/or mismanaged and, eventually, suffer land and ecosystem degradation.

According to the Global Forest Resources Assessment (FAO 2005), forests currently cover about 3.9 Gha worldwide, or 30 percent of total land area. The forest area is unevenly distributed worldwide, with 52 percent of forests in low latitudes (approximately 0-25° N and S latitude), 30 percent in high latitudes (approximately 50-75° N and S latitude), and 18 percent in mid-latitudes (approximately 25-50° N and S latitude). Based on a sub-regional summary of the distribution of forests, Europe and Russian Federation accounts for one-quarter of total forest area (5 percent and 20 percent respectively), followed by South America (21 percent) and North and Central America (18 percent). Other wooded land distributed worldwide is estimated to be at least 1.3 Gha, representing about one-third of total forest area (Figure 1).

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Figure 1. The world’s forests. Source: (FAO 2005.

The worldwide forest status can be represented by four main categories (Figure 2, Global Forest Resources Assessment FAO 2005):

Primary forest, in which there are no clearly visible indications of human activity and ecological processes are not significantly disturbed (36 percent of total forest area).
Natural forests consisting of naturally regenerated native species in which there are clearly visible indications of human activity (53 percent).
Semi-natural forests, comprising native species, and established through planting, seeding or assisted natural regeneration (7 percent).
Forest plantations, representing forests of introduced species and in some cases native species, established through planting or seeding (4 percent): a. Productive forest plantations (3 percent); b. Protective forest plantations (0.8 percent).

Within the other wooded land, 69 percent is classified as modified natural, 28 percent as primary and the remaining 3 percent as semi-natural.

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Figure 2. Forest Characteristics. Source: (FAO 2005)

Forests provide a wide range of ecosystem services that contribute significantly to the overall economic and social development of humankind. Forest ecosystems and shrublands have, in most cases, a high or very high level of complexity that directly impacts on their ability to simultaneously provide multiple and differentiated ecosystem services and, consequently, raises the need to adopt proper and efficient management methods, especially in the perspective of their high social, economic and ecological importance (Daily 2000; Kremen 2005). The management complexity of forest ecosystems and shrublands is mainly due to:

the high number of ecosystem services (i.e. higher than agricultural or simplified pastoral systems);
the diversity of ecosystem services (i.e. regulating, supporting, production, cultural);
the types of ecosystem services ((i.e. direct, indirect, tangible and intangible) (Gee and Burkhard 2010));
the scale of influence (i.e. from site-specific to global);
the interdependence and interrelationship among forest ecosystem services and other types of ecosystems.

The range and importance of forest ecosystem services are also diverse and primarily depend on the biophysical and socio-economic setting. The lack of an efficient system for forest service valuation and its inclusion in national economic accounting is responsible for the poor recognition of their overall contribution (Croitoru 2007). The most important forest ecosystem services are: conservation of biodiversity; protection of watersheds and regulation of hydrological cycles (Pinto et al. 2010); mitigation of desertification and land degradation processes; and regulation of biogeochemical cycles through carbon sequestration and storage. For these reasons, forest ecosystem complexity needs to be preserved through proper and efficient forest management, to improve the contribution of forest services to social, economic and ecological cohesion as fundamental components of human well-being ((MEA 2005) Figure 3).

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Figure 3. Linkage between Ecosystem Services and Human Well-being. Source: (MEA 2005:28)

For forest and shrubland ecosystems in particular, it is possible to define the ecosystem services reported in Table 1, both by type, scale (MEA 2005; De Groot et al. 2010; Vihervaara et al. 2010; Pinto et al. 2010; Petrosillo et al. 2010; Yapp et al. 2010) and principal dimension of interest (Pinto et al. 2010; Gios and Clauser 2009).

Table 1. Main ecosystem services as functions of services type, dimension of interest and scale

Service	Type	Principal dimension of interest	Scale
Regulating	Climate and microclimate regulation Carbon sequestration Pollination Water regulation (flood control/prevention) Drought mitigation Soil erosion protection/prevention Natural hazards mitigation	ecological ecological - econ. ecological ecol. - econ. - social ecological ecol. - econ. - social ecological - social	local - global regional - global local local - regional local - regional local local - global
Supporting	Disturbance regulation/mediate (includes human disturbances and natural hazards mitigation) Soil fertility recovery/generation Waste treatment (Detoxification and decomposition of wastes) Purification/control of water and air Biological regulation and pest control (bioremediation) Nursery habitat; Support critical life cycle requirements and provide structural and nutritional niches (photosynthesis) Biodiversity conservation Wildlife protection Water supply and water quality Employment support	ecological ecological - econ. ecological - econ. ecological - econ. econ. - ecological ecological ecological ecological econ. ecological econ.	local – regional local local - regional local - regional local - regional local local - regional local - regional local - regional local
Provisioning	Timber products (raw materials), Non-Wood Forest Products (NWFPs) Fibre Renewable energy, fuel Food (nuts, mushrooms, fruits, honey, spices, herbs, flavourings,) Biochemical products (plant and animal products with medicinal value.) Pasture (fodder for cattle, sheep and swine) Genetic resources	econ. - ecological econ. - ecological econ. - ecological econ. - ecological econ. - ecological econ. - ecological ecological	local local local local local local local - regional
Cultural	Cultural and diversity, sense of place and identity, knowledge systems and cultural heritage values Educational values Cognitive and spiritual services, inspiration and aesthetic values Social relations Recreation and ecotourism	social social - econ. social social - econ. social	local - global local - global local - global local - regional local - regional

Source: (Adapted from De Groot et al. 2010; Gios and Clauser 2009; MEA 2005; Petrosillo et al. 2010; Pinto et al. 2010; Vihervaara et al. 2010; Yapp et al 2010).

Table 1 highlights the high level of diversity in type and scale of forest ecosystem services and the complexity of forest ecosystem functions. This complexity is a function of the distribution of forests globally, with different types of services related to climate, forest type, social and economic assets. On a global scale, forests affect climate through biophysical properties such as albedo, which controls the amount of incoming solar radiation that is reflected back to the atmosphere, regulating the amount absorbed and converted to heat (Ollinger et al. 2008; Lohila 2010). Forests have lower albedo in comparison to grassland, desert or ice and snow cover (Table 2 and Figure 4), absorbing most of the incoming solar and infra-red radiation. Some of this energy is used by the trees for photosynthesis but a greater part is released as 'sensible heat', creating a warming effect and raising the atmospheric temperature (Bala et al. 2007; Bonan 2008). In the Mediterranean environment, forest ecosystem services are mainly related to regulating functions such as climate and microclimate regulation, biogeochemical cycles (carbon and water), drought mitigation, soil erosion protection and prevention, and land degradation and desertification prevention (Croitoru 2007; Petrosillo et al. 2010). In particular, these ecosystem services are related to soil protection from wind erosion, coastal protection from shoreline erosion and crop protection from salt-spray and aerosols.

Table 2. Radiation-weighted annual means of surface albedo of vegetation types in the Northern Hemisphere (1991-2000).

Dominant vegetation type	Annual albedo
Tropical evergreen forest Tropical deciduous forest Temperate evergreen broadleaf forest Temperate evergreen conifer forest Temperate deciduous forest Boreal evergreen forest Boreal deciduous forest Mixed forest Savanna Grassland Dense Shrubland Open Shrubland Tundra Desert Land Ice	0.09 0.11 0.11 0.10 0.13 0.18 0.20 0.16 0.13 0.19 0.15 0.21 0.38 0.24 0.52

Source: (Bala et al. 2007).

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Figure 4. Albedo of the Earth's terrestrial surface as measured by the TERRA satellite. Data collected from the period April 7-22, 2002. Source: (NASA Earth Observatory. Available online at: http://earthobservatory.nasa.gov/IOTD/view.php?id=2599).

Forests also play a very significant role in regulating the global carbon cycle, which affects global climate change. In particular, forests absorb atmospheric carbon dioxide during photosynthesis, storing carbon in wood, leaves, roots and soil, representing above and below-ground biomass. In this way, forests represent a carbon sink in the global carbon cycle. At the same time, forests release carbon dioxide to the atmosphere through respiration and organic matter oxidation processes, as well as through the deliberate or unintended results of human activities (i.e. harvesting, fires, deforestation), representing a carbon source. The contribution of forests to carbon cycles must be evaluated, taking into account the use of harvested wood, e.g. wood products storing carbon for a certain period of time, or energy generation releasing carbon in the atmosphere. In cases the net balance of carbon emissions by forests is negative, i.e. carbon sequestration prevails, forests contribute to mitigating carbon emissions by acting as a carbon sink to sequester additional carbon. In cases where the net balance of carbon emissions is positive, forests contribute to the greenhouse phenomenon and climate change.

The role of forests in regulating the global carbon cycle is affected by both changing climatic conditions and human activities. Changes in rainfall and temperature can have either damaging or beneficial impacts on forest health and productivity, which are very complex to predict. Depending on the circumstances, climate change may produce a shift of forest cover towards higher elevations and latitudes and will either reduce or increase carbon sequestration into forests, which causes uncertainty about the extent to which the world’s forests can contribute to climate change mitigation in the long term. Forest management activities have the potential to influence carbon sequestration by stimulating certain processes like forest regeneration or expansion and forest productivity and mitigating the impacts of negative factors (Nabuurs et al. 2007).

Another important ecosystem service provided by forests is the protection and regulation of water resources through the reduction of surface erosion and sedimentation; moderation of floods; enhancing precipitation (e.g. ‘cloud forests’) and mitigating salinity. Forests also provide protection from natural hazards such as snow avalanches and landslides. Other relevant ecosystem services of Mediterranean forests and shrublands in particular include supporting functions such as biodiversity conservation, genetic resources, wildlife protection, water supply and water quality by filtering water pollutants and regulating water yield and flow (Chazdon 2008).

On a local scale, forest and shrubland ecosystem services provide provisioning services, due to their capacity to produce a wide range of wood and Non-Wood Forest Products (NWFPs), such as timber products, renewable energy, food (berries, mushrooms, edible plants, bushmeat) and pasture. These services provide employment opportunities in the processing and trade of forest products and energy. Finally, forest and shrubland ecosystem services also include cultural services as forests create sites and landscapes of high cultural, spiritual or recreational value.

One of the key factors which influence conservation of forest ecosystem complexity and of related ecosystem services is the forest management system (De Groot 2010).A simple change in forest management or land use may lead to a significant change in the supply of ecosystem services.

The economic benefits derived from forests are usually measured in monetary terms and include: income from employment in the forest sector; the value of forest goods and services; the contribution of the forest sector to the national economy; energy supplies and international trade. In this case, the economic benefits of the forest sector can be assessed by measuring the profitability of forest enterprises, or levels of investment.

The social benefits of forests are often more difficult to measure and can vary considerably among countries, depending on their level of development and their forest use traditions. For example, at the global level, almost 4 percent of forests are managed primarily for recreation, education, tourism and other social services. In most cases, touristic and recreational functions are more developed and managed in Europe and North America. According to the National Visitor Use Monitoring Results of the USDA Forest Service (2009), in the period from 2005 to 2009 about 170 million people visited US National Forests System and Wilderness for tourism or recreational purposes. At the European level, the number of annual of visits is estimated to be much higher than North America, as shown in Table 3.

Table 3. Estimated number of forest visits in European countries.

Source: (MCPFE 2007).

Characteristics of forests & shrubland: Italy and Matera

2012-06-15T09:57:56+00:00

Authors: Agostino Ferrara, Guiseppe Mancino, Luca Salvati

{xtypo_alert}Editor's note 15Jun2012: Text source D311-2.2{/xtypo_alert}

The Italian peninsula occupies an area geographically situated between 36° and 47°30’ North latitude and between 5°30’ and 18°30’ East longitude. Its orography is quite complex due to the presence of two main mountain ranges, the Alps in the north and the Apennines in the centre-south. Due to this geographical and orographical heterogeneity, the Italian climate is also very variable following the latitudinal and altitudinal gradients and the distance from the sea. In general, the Italian climate ranges from Mediterranean warm to temperate cool (Chirici et al. 2007). This variability, combined with a high population density, produces a complex distribution and composition of forests. According to the forest map derived from the CORINE Land Cover 2000 map (Figure 1), forests (including shrubland) cover nearly 9.2 Mha in Italy (Maricchiolo et al. 2004) with 95 percent of forests located in mountainous and hilly regions. Half of the forests (52 percent) is located in the Mediterranean region, 32 percent belong to the Alpine biogeographical region and 16 percent to the Continental region (Habitat Directive of the European Commission 43/92).

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Figure 1. Forest distribution in Italy (raster format with geometric resolution of 1 km²). The nomenclature system is an aggregation of the original one, which is derived from the CORINE Land Cover dataset. Forest types classes: 1 White fir/Norway spruce forest; 2 Chestnut forest; 3 Exotic conifer forest ; 4 Beech forest ; 5 Exotic broadleaf forest; 6 Hygrophilous broadleaf forest; 7 Mediterranean broadleaves ; 8 Holm oak ; 9 Bushlands; 10 Mediterranean pine forest; 11 Mountain pine forest; 12 Other oaks. Source: (Chirici et al. 2007).

Italian forest ecosystems are also characterised by a pronounced biodiversity with 117 native forest tree species. Beech, deciduous and evergreen oaks, poplars and chestnut represent most widespread forest types. The main conifer forests are those of Abies alba and Picea abies, followed by other Pine forests. Fifty-three percent of forestland is managed as coppices, 43 percent as high-stands, and 4 percent is Mediterranean macchia. Even-aged stands represent 60 percent of the total high stands (Corona et al. 2004). Individuals privately own two thirds of Italian forests, in small holdings, and one third is publicly owned, mainly by Regions and Municipalities (FAO 2003).

Mediterranean forests and shrublands represent one of the most important ecological systems because of their rich biodiversity; they are recognized as biodiversity hotspots (Myers et al. 2000). On a continental scale, Mediterranean forests cover only 8.5 percent of the European land area but they host about 25,000 species of vascular plants with a high degree of genetic diversity and endemism (about 50 percent of the species are endemic). Despite this high level of biodiversity, Mediterranean forests and shrublands represent one of the most vulnerable ecosystems with high levels of fragility and instability due to several environmental and human-induced pressures including climate change, recurrent fires, human activities and land use changes.

Mediterranean forests have played a crucial role in the rise and development of some of the oldest civilizations, thanks to their multifunctional environment which offers a wide range of important benefits and services to society and human welfare beyond traditional forest wood products. Over the centuries, a mosaic-like structure emerged from the complex interactions of forests and shrublands with other land uses such as agriculture, pasture and urban or industrial areas. One of the most important forest functions in the Italian territory, as elsewhere, is the capacity to maintain and regulate water and soil resources, protecting watersheds and regulating local climate, generally mitigating severe summer droughts and desertification processes. Other important socio-economic development benefits include protection of soil against erosion and salinisation processes, carbon sequestration, recreation and landscape scenic value, supporting tourism development. These forest services provide more benefits to the local communities than to their individual owners. In fact, the production of wood products based on traditional forestry suffers from decreasing profitability as a result of high extraction costs. This situation leads to general forest abandonment, the consequences of which include increased fire risk and phytopathological diseases. In rural areas, the main threats to forests include overgrazing and forest clearance for agricultural use.

The Basilicata region is located in Southern Italy and its territory includes the 'Mediterranean coastal and upland study site in Matera prefecture' that represents and embodies most of the climatic, environmental and socioeconomic aspects and characteristics of Mediterranean regions.

The Basilicata Region covers approximately 10,000 km². It is located between the Regions of Calabria, Campania and Puglia and also borders with the Tyrrhenian Sea to the west and the Ionian Sea to the south. The Region is mainly hilly-mountainous with a flat area in the south. The mountainous area is essentially in the west, representing 47 percent of the total territory. It includes the Apennine Mountains, which cross the region in a northwest-southeast direction. Mount Pollino (2248 m a.s.l.) is the highest mountain. The rest of the Basilicata Region is characterized by hills (45 percent of the land area) and by plains (8 percent of the land area). The mean annual rainfall varies across the region from 500 mm to 2,000 mm in the southwest. The rainfall is irregularly distributed during the year and between years, as it is common in a typical Mediterranean climate (maximum precipitation in autumn and minimum during the summer). The region is within the annual isotherm of 11°C-15°C (De Stefano and Lorusso 2000).

In the mountainous areas, forestry, agriculture and pastures represent the most important economic activities. Forests cover 35.6 percent of the territory (Figure 2). Oak forests, composed of different species (Quercus sp.), occupy 51.8 percent of the total forest cover, beech (Fagus sylvatica) 8.4 percent, Mediterranean bush 7.9 percent, forest plantations only 0.6 percent, and conifers 7 percent. The altitudinal distribution of forests is as follows: 60 percent are located between 400 m and 1200 m altitude, less than 9 percent above 1200m, and 20 percent is located in less than 400m altitude.

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Figure 2. Basilicata Region Forest Map. Source: (Costantini et al. 2006)

The Mediterranean forests of the Basilicata Region include a range of different types such as pinewood forests of artificial origin located in retro-dune zones, reforestation with Mediterranean pines in the calanchi (“badlands”) and the Mediterranean macchia and garrigue mainly found in the Ionian coastal zones. These habitats represent a fragile environment with a high risk of land and ecosystem degradation.

On the coastline, the pinewood forests are artificial in origin in that they have been planted since the mid-1930s. Major reforestation took place between 1950 and 1970, with Southern Italy Development Funds. The main objective of reforestation was to consolidate the coastal dunes and to create an efficient and wide windbreak strip to protect inland agricultural crops from marine aerosol fluxes. The species most commonly used were Pinus halepensis (the majority), Acacia saligna, Eucalyptus globulus, Eucalyptus rostrata, Pinus pinea and Tamarix gallica. Less used species include Cupressus sempervirens, Pinus pinaster and Pinus canariensis.

One of the main effects of the protective function of coastal reforestation is the development of inland intensive agriculture. Thus, coastal reforestation can be considered as one of the main drivers for the growth of the economic use of the coastal area. The best reforestation results are due to the use of Pinus halepensis (which is native in the Ionian area) rather than Pinus pinea. The forests are 30 to 80 years old, generally even-aged, and they show very different conditions of growth, depending on stand characteristics and thinning. Areas without intervention are often characterized by high incidence of deadwood or trees with poor growth habit and these represent a significant fire hazard. Frequently, phytosanitary problems are also encountered, for example intense attacks of Thaumetopoea pityocampa.

The second forest type is represented by the reforestation of the calanchi (“badlands”) with Mediterranean pines. In this case also, this forest type has been planted for protective purposes. In fact, the erosion phenomenon of calanchi badlands concerns a large part of the Ionian area of Basilicata and the main manifestations are found in Aliano, Craco, Pisticci, Montalbano Jonico, Tursi and other adjacent areas. These erosion phenomena, due to their characteristics, are considered a site of extraordinary geological interest, protected by the institution of Geological Reserves within the natural boundaries represented by the Sauro torrent in the west side and by the Basento river in the east part.

The calanchi badlands principally originate in argillaceous soil, in which the surface water run-off causes a “combined erosion” process represented by channel erosion and repeated superficial slides, resulting in a dynamic sequence of channels separated by crests. In general, the south side of the calanchi badlands are much steeper because of the combined actions of sun and rainwater. The sun desiccates the soil, creating a network of cracks in which rainwater run-off starts the erosion process. The north side of the calanchi badlands are generally characterized by a gentle slope, allowing agricultural practices like olive groves and grazing of natural formations like Mediterranean bush (Figure 3).

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Figure 3. Calanchi badlands in the Matera study site. Source: (Author Angelo Nolè).

In general, the calanchi “badlands” are a very inhospitable environment for vegetation because of steep slopes, instability of the soil, high soil salinity and long periods of drought. As a result, vegetation is sparse and is characterised by plants that can tolerate the salinity and have specific adaptation mechanisms. Main species are Capperis spinosa, Tamarix africana, Spartium junceum, Psolearea bituminosa, Ligeum spartium and Glycirrhiza glabra.

In order to increase the vegetation cover and limit erosion processes, a broad afforestation programme was realised in many calanchi badlands, between1950 and 1960 in particular, using Mediterranean pines like Aleppo pine (Pinus halepensis), stone pine (Pinus pinea) and maritime pine (Pinus pinaster) (Figure 4).

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Figure 4. Mediterranean pine afforestation in Calanchi badlands near Aliano in the Matera study site. Source: (Author Giuseppe Mancino).

In some areas it is possible to find other species, in particular eucalyptus (Eucalyptus spp.) and cypresses (Cupressus sempervirens and Cupressus arizonica). The Mediterranean pine forest type includes both artificial populations and natural populations of Aleppo pine representing 5.5 percent of the Basilicata Region forest cover. The environmental sensitivity to desertification risk of these formations is sufficiently elevated (mean ESAI value equal to 1.32) as testified by sub-optimal vegetation and phytosanitary conditions. These conditions are also due to environmental constraints (scarce rainfall, elevated summer temperatures, extended periods of drought, bad edaphic conditions) and human pressure. High fire frequency is an issue, due to intense agricultural activities in the adjacent areas, meteorological conditions that favour ignition and grazing that often exceeds the capacities of these top-soils.

The last forest type is represented by shrublands, in particular the natural and semi-natural Mediterranean macchia and garrigue that are subjected to strong environmental pressures and alterations in the Basilicata region. The extent of Mediterranean macchia in Basilicata represents 7.9 percent of the total forest area of the region. This vegetation cover is typical of the Mediterranean basin. Plants in this forest type are adapted to the particular climatic conditions, high temperatures and low rainfall, which limit the number of species living in this area. The forest physiognomy is characterised by broadleaf evergreen trees and bushes, such as the Holm oak, and principally rock roses, lentisk, myrtle and rosemary. The garrigue is typically represented by rock roses, lentisk and rosemary and covers about 5.923 ha of the Basilicata Region (1.7 percent of the total surface), distributed in the territory near Matera along the Ionian coastal zone.

The garrigue represents a particular association between shrub and herbaceous species of Mediterranean plants, from sea level to 1400m. Its presence is related to degraded conditions of rocky, steep and arid soils, where excessive grazing and repeated harvest felling, accompanied by frequent, often annual use of fire to stimulate grass re-growth, has prevented forest evolution. The main types of species are geophytes and sclerophylls, characterized by hard leaves and the thorns and they are adapted to cope with livestock grazing and long periods of aridity. Due to the discontinuity of its cover, the garrigue is a susceptible ecosystem and vulnerable to degradation and desertification in Mediterranean environments.

Characteristics of forests & shrubland: Spain, Portugal and Baixo Guadiana

2012-06-18T06:01:40+00:00

Authors: Michiel Curfs, Anton Imeson

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Characteristics of forests & shrubland in Spain

{showhide title="»more details ..." changetitle="«more details ..."}Spain comprises about 84 percent of the Iberian Peninsula. It occupies an area geographically situated between latitudes 360 and 430N and longitudes 90 W and 50 E. The orography is characterised by a high average altitude. Spain is the second highest country in Europe; 57.7 percent of the territory rises more than 600 metres above sea level. The arrangement of the mountain ranges following a west-east general direction with the exception of the ‘Sistema Ibérico’ and the ‘Cordilleras Costeras de Cataluña’, exerts a major influence on the climate, creating as it does natural barriers which prevent the wet air masses from the Atlantic from moving inland. The hydrological regime mainly depends on the precipitation pattern, which is abundant from autumn to spring and scarce or non-existent during summer. The hydrographic network is modified by a system of hydraulic works that regulate river flows for human consumption, electricity generation and agricultural purposes (EEA SOERa 2010). Spain has wide climatic variability and includes oceanic, continental and Mediterranean climate types.

Spain’s climatic and lithological heterogeneity has helped to create a highly compartmentalised territory, which in turn has brought about a variety of vegetation and landscape types, from forests similar to those of Atlantic Europe up to and including sub-desert steppe and subtropical plant formations. The modern landscape of Spain is a mosaic in which natural woodland, brushwood and herbaceous formations, along with farming and reforested areas, are unevenly distributed throughout the territory. This variety of landscapes finds its main expression in a rich flora consisting of over 26,500 taxa; 8,000 of which are vascular plants (EEA SOERa 2010). The definitions of forest differ among countries and institutions. For instance, the percentage of tree cover is an indicator that is used to define what a forest is. These differences in definitions also lead to different information of how much area is classified as Forest. According to FAO, the forest area in Spain is 14.4 million hectares, making it the fourth biggest country in Europe in terms of forest resources. Forests occupy almost 29 percent of the total land area and this figure is increasing by about 86,000 ha per year. The growth of forest cover has been through natural expansion and through a forest plantation programme which has been operating for more than 50 years, with soil protection and erosion prevention as its main aims (FAO 2011). Spain has received funds from the European Union in support of this program (http://www.fao.org/forestry/country/57478/en/esp/). According to the Spanish definition of a forest, the ’Ministry of Environment , rural and marine affairs´ (Ministerio de Medio Ambiente y medio Rural y Marino) defines 27.6 million ha as an extensive forest (wooded) area. The extensive forest contains a large number of agricultural, forest and transitional ecosystems that have emerged as a result of human activity within the natural environment (MARM 2011).

The most productive forests are found in the Atlantic coastal zone and are composed primarily of pines (Pinus pinaster and P. radiata) and eucalyptus (Eucalyptus globulus), although some mixed natural forests of oak (Quercus robur and Q. patraea) and beech (Fagus sylvatica) are also found. In the Pyrenees, there are forests of silver fir (Abies alba), beech and pine, depending on altitude. The remainder of the country, where Mediterranean conditions predominate, is notable for its wealth of biological diversity. In some places Quercus spp. are found in pure stands, constituting wooded meadows (an agro-silvo-pastoral combination typical of Mediterranean zones) or mixed with pines and a wide variety of shrubs and scrub vegetation. In mountainous Mediterranean regions Pinus spp. becomes increasingly frequent as the altitude increases (FAO 2011).

Sixty-six percent of forest lands belong to approximately two million owners, 30 percent to municipalities and only four percent to the autonomous communities. However, most municipal forests are public service forests (a special forest protection legal category dating back to 1850) and these forests are managed by the autonomous communities. About 25 percent of forests are classified as protected areas. The main function of 88 percent of Spanish forests is to protect the soil against erosion and desertification and to regulate the hydrological cycle, in a country with steep slopes and scant, irregular rainfall. The remaining 12 percent are mainly production forests, which produce 80 percent of the total supply of roundwood. Non-wood forest products such as cork, gum and medicinal and aromatic plants are also important. Other non-wood forest products and services include hunting, fodder, nuts, fruit and truffles. Landscape aesthetic value, tourism, leisure and recreation are increasingly important uses of forests in Mediterranean zones (FAO 2011).

The administrative organization of Spain is decentralized. The Autonomous Communities and cities take on the environmental competences which have been transferred to them, and so they play a decisive role in the definition and implementation of environmental policies in close coordination with the General State Administration. Each of these Autonomous Communities has a competent organization for environmental matters and has the ability to create their own Environmental Agency or similar institutions. There are 17 Autonomous Communities and two Autonomous Cities.

Spain has two clearly defined types of protected natural areas: Protected Natural Areas (designated under Law 42/2007, on Natural Heritage and Biodiversity) and protection granted by inclusion in the Natura 2000 network. Spain's protected natural areas also include those covered by international agreements, such as Wetlands of International Importance (designated under the Ramsar Convention) and Biosphere Reserves. As far as biodiversity protection is concerned, attention must be drawn to the important effort made by Spain. In 2009, 27.65 percent of the whole of Spanish territory was under protection, either by having been declared as Protected Natural Areas (PNA) or through its inclusion in the Natura 2000 Network. The number of PNAs is 1,519 encompassing a total area (terrestrial as well as marine of 6,174,788 hectares. The Sites of Community Importance (SCI), both on land and on the sea, amount to 1,435 while the number of Bird Special Protection Areas (BSPA) stands at 594. In this regard, the great importance of numerous Spanish spots for bird migration between Africa and Europe must be highlighted. Such an effort for the protection of biodiversity has been acknowledged by the UNESCO MAB programme, since Spain is the third country in the world (after the United States and the Russian Federation) in terms of numbers of Biosphere Reserves (EEA SOERa 2010).

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Characteristics of forests & shrubland in Portugal

{showhide title="»more details ..." changetitle="«more details ..."}The physical environment in Portugal varies considerably, creating several distinct geographic regions which have shaped the culture of the people, their economy and society. Even though it is a relatively small country, Portugal has a diversity of landforms, climatic conditions and soils. The major geographical difference is between the mountainous regions in the north and the wide plains in the south. Within these two major regions are further subdivisions. Northern Portugal is a mountainous, rainy region characterised by many small farms and vineyards. Central Portugal, including the capital Lisbon and its surroundings, is less homogeneous. The greater Lisbon area, including both the city and its suburbs, accounts for most of the nation's commerce and much of its industry. Southern Portugal, known as the Alentejo, is an area of gently rolling hills and plains dominated by extensive estates with large-scale agriculture and grazing. The extreme south of Portugal is known as the Algarve. It is a dry region characterised by small-scale grazing agriculture and fishing communities. With its warm Mediterranean climate and a high concentration of golf courses that use up the region’s scarce water resources, the Algarve has become a centre for tourism and a home to many foreign retirees (Solsten 1993). Tourism is one of Portugal’s main activities and accounts for roughly 10 percent of GDP (EEA SOERb 2010).

Land use changes have modified the Portuguese landscape, ecosystems and environment. Urban areas consume significant quantities of resources at the expense of agricultural lands. Rural landscapes are also undergoing change, with intensification of farming and forestry activity on one hand, and abandonment of the land, on the other (EEA SOERc 2010). Land use change mapping activities carried out between 2000 and 2006 reveal that during this short period of time, approximately 8.6 percent of the land area was modified. These modifications include the expansion of artificial surfaces, such as roads and buildings (an increase of 10 percent or 28,000 hectares), construction of dams (in particular, the Alqueva dam and the extension of its influence) and the conversion of agricultural areas into areas with natural vegetation and vice-versa (APA 2009). In 2006, 71 percent of continental Portugal consisted of forest and agricultural land and approximately 15 percent was a mixture of agricultural land use and natural areas. Artificial surfaces represented 3.5 percent and natural vegetation took up 8.6 percent of land cover (IGP 2009). In spite of land use changes, the overall distribution remains comparable to that registered in 2000. Forests and areas of natural vegetation continue to dominate land cover in continental Portugal and remain the focus of the most dynamic changes.

Afforestation is shaping the landscape, mainly in the centre of the country. The trees used for afforestation are mainly fast growing tree species such as eucalyptus (EEA SOERc 2010). A contributing factor to the changes occurring in this land use sector are the numerous forest fires which affect the country every year and have a significant impact on the landscape and land cover. Although forest areas have been converted to other uses, new forests have also been planted. Between 2000 and 2006, there was a net increase of 30,000 hectares of forest cover. In contrast, areas covered by natural vegetation declined by 27,000 hectares or 3.5 percent (APA 2009). Between 2000 and 2006, over 28,000 hectares of agricultural, forest and other semi-natural and natural land was converted to urban areas and other artificial developments. Exactly 50 percent of that amount was taken from forests and 40 percent from agriculture.

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Characteristics of forests & shrubland in the Baixo Guadiana study site

The study site area Baixo Guadiana lies in the lower Guadiana Basin, which is situated at the south western part of Iberia (Figure 1) at the border between Spain and Portugal.

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Figure 1. The study site area on the Iberian Peninsula. Source: (Author Michiel Curfs)

The Baixo Guadiana represents and summarizes most of the aspects and characteristics of the Mediterranean areas, with a high severity of climate, environment and socio-economic features. The area has the marked characteristics of Mediterranean climate with long, dry periods and high temperatures during summer, associated with a trend of decreasing average annual rainfall that falls in irregular showers. This has negative influences on the ecophysiological efficiency of forests and their phytosanitary status, and can trigger increasing erosion rates. The Baixo Guadiana is a rural area with low population density in the interior and higher population density in the coastal zone. The lack of development opportunities in the interior area has led, and still leads to, unemployment. This is a cause of the negative demographic trend with consequences on the age structure of the population, causing a gradual shift in demographics from younger classes to the elderly. An ageing population structure is a common phenomenon in the interior municipalities. Depopulation is pronounced in the interior parts of the study area. The decline in population is a phenomenon found in almost all municipalities in the Baixo Guadiana however, the coastal municipalities show an increase in population. Littoralisation can clearly be observed in the Baixo Guadiana area. The positive demographic trends in the coastal zone are related to the fact that the coastal municipalities are the most socio-economically vital areas of the Baixo Guadiana, with tourism being the most important activity.

Shrubs and herbaceous cover are the main land use form, representing 42 percent of the total territory of the international Lower Guadiana area. Thirty five percent of the territory in the Lower Guadiana area has undergone changes in land use between 1990 and 2006 (Figure 2).

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Figure 2. Vegetation cover of the Forest divisions in the Baixo Guadiana area in 1990 and in 2006. Source: (Adapted from Felicidades Garcia 2010)

Nearly 30,000 hectares of farmland have become forested areas, of which 20,500 ha have become agro-forestry. The forest area has increased by approximately 16,000 ha in 16 years, but this increase masks a much larger transformation, which is the radical change in floristic composition (Figure 3). This change can be summarised as follows: The forest surface has decreased by 30 percent, a decrease in area of approximately 4,500 ha. There is a more evident decrease in the matorral without trees areas. This division has decreased by 50 percent. However, there has been a large increase in area of the division of matorral with trees. This has increased by 583 percent from 1990 to 2006, an increase in area of nearly 70,000ha (Felicidades Garcia 2010). This last division, the matorral with trees, can be described as young dehesas and montados; the trees that are planted consist mainly of Holm oak.

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Figure 3. Distribution of forest vegetation cover in the forest division. Source: (Adapted from Felicidades Garcia 2010)

Dehesas and montados with its Holm oak (Quercus ilex) and Cork oak (Quercus suber), constitutes the largest forest type in the geological Pyrite belt area, and more generally in the whole of the Mediterranean forests (Figure 4).

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Figure 4. The Dehesa in the Baixo Guadiana in April. Source: (Author Michiel Curfs)

Dehesas and montados are forest areas in which the distance between trees should be kept at a density which is in equilibrium with its land use, in that they are forests that allow development and use of pasture by livestock grazers. The conservation of this type of forest is related to its economic functions, which are critical to the profitability of the system. The density of trees should meet the requirements for natural light of grassland, and also facilitate the movement of livestock (Olea and Miguel-Ayanz 2006).