{xtypo_alert}Editor's note 14Jun2012: Text source D211, section 3.2.{/xtypo_alert}

In »LEDD issues in grazing land worldwide we introduced and discussed the main LEDD issues which concern grazing land worldwide, in the countries where the study sites are located and in the broader regions of the study sites themselves. These LEDD issues do not occur in isolation but are driven by interdependent environmental, economic and social processes, operating at multiple scales, singly and in combination with each other.

This section of LEDDRIS we will discuss these key drivers at global, national and regional spatial levels. Policy drivers are discussed here only briefly. For a full discussion of policy drivers in the three land themes, please refer to »Policy context and policy recommendations for LEDD in cropland: general.

The MEA (Millennium Ecosystem Assessment 2003, p.15) defines direct and indirect drivers of ecosystem change and their relationship as follows:

• "A driver is any factor that changes an aspect of an ecosystem.
• A direct driver unequivocally influences ecosystem processes and can therefore be identified and measured to differing degrees of accuracy.
• An indirect driver operates more diffusely, often by altering one or more direct drivers, and its influence is established by understanding its effect on a direct driver.
• Both indirect and indirect drivers often operate synergistically. Changes in land cover, for example, can increase the likelihood of introduction of alien invasive species. Similarly, technological advances can increase rates of economic growth".

In LEDDRA, the above distinction is adopted. Practically, direct drivers of LEDD are intentional and unintentional human activities and interventions that cause changes to the characteristics of the environment; i.e. they cause LEDD directly (e.g. land management practices, deforestation, overgrazing, etc.). Indirect drivers are those socio-economic, cultural, institutional, political and other forces that drive people to undertake activities that may or may not cause LEDD (e.g. demand for food, prices, policies, norms, property rights, etc.).

Table 1 below presents the direct and indirect drivers of LEDD in grazing land. Drivers operate at all spatial levels (global, national, regional, local); their specific operational form depending on the level concerned.

Table 1. Direct and indirect drivers of LEDD in grazing land

Source: (Adapted from Millennium Ecosystem Assessment 2003)

As noted above, the MA defines a driver as any natural or human induced factor that indirectly or directly causes a change in an ecosystem. For example, climate change and land-use change are the two most important drivers affecting land degradation in grazing land. Land degradation refers to the loss of primary production not only through soil erosion but also through changes in vegetation and ecosystem processes such as carbon sequestration (M.E.A. 2005). Analyses of grazing systems should be conducted without forgetting the ecological perspective because feed resources are regulated by biomass production, rainfall and evapo-transpiration processes, which are directly influenced by climate.

Traditional land use change has important consequences on the conservation of grazing land.  Many mountain landscapes are the result of human influences to increase food production (Ellenberg 1988a; García-Ruiz and Lasanta 1990; Montserrat and Fillat 1990). For example, numerous agro-pastoral systems lead to a mosaic of grasslands, shrublands and forest (Farina 2000; Pasche et al. 2004; Bartolomé et al. 2005) where extensive grazing and transhumance practices are important and enable such landscapes to be maintained (Di Pietro 2001). These semi-natural landscapes have great cultural interest because they maintain a large pool of biodiversity (Austrheim et al. 1999; Pärtel et al. 1999; MacDonald et al. 2000; Pykälä 2000). Nowadays, such landscapes are under  pressure from a range of  different interests: agriculture, forestry, tourism and nature protection (Fischer 1990). Balancing these sometimes competing demands with natural processes, such as succession, is not always easy. At present intensification in the use of accessible sites is increasing in parallel with abandonment of less accessible sites in the European Alps (Tasser and Tappeiner 2002) and in other parts of the world.

Indirect drivers act over the direct drivers, as for example changes in population demography, influencing energy demand, economy and socio-political will indirectly affect grazing land.  For example, agricultural modernisation and rural depopulation of many mountain areas leads to abandonment of traditional farming; shrub and tree encroachment (Austrheim et al. 1999; Poyatos et al. 2003; Pykälä et al. 2005; Lasanta et al. 2006; Gehrig-Fasel et al. 2007; Tasser  et al. 2007) and to homogenisation of the landscape structure (Burel and Baudry 1995; Olsson et al. 2000; Dullinger et al. 2003b; Laiolo et al. 2004; Isseltein et al. 2005). Other indirect drivers are originated from present socio cultural needs, where herders tend to spend more time close to villages or in larger settlements to acquire access to markets, education, and medical and employment services (Ringrose et al. 1996; Fernandez-Gimenez 2002; Kazato 2005; Dembele et al. 2006). Herders also tend to remain close to roads that are connected to cities (Muller and Bold 1996; Okayasu et al. 2007). This results in intensification of grazing activities around specific locations.

At the same time direct and indirect drivers interact. Thus, the way that land use and climate change influence grazing lands depends not only on the climatic conditions but also on the industrial development of the country in question. During the last 50 years, the population in the Maghreb has increased three-fold, leading to over-exploitation of rangelands and desertification, while in northern Mediterranean countries (Portugal, Spain, France and Italy) only a 30 percent increase was reported (Puigdefábregas and Mendizabal 1998). In northern Mediterranean countries, migration  to cities and intensification of agriculture have led to land abandonment, which enables soil and vegetation to recover, although in many cases soils are so exhausted and degraded that recovery is difficult (Puigdefábregas and Mendizabal 1998).

Sometimes, authors do not agree on the drivers of land degradations. For example, the use of communal pasture has been generally considered as the cause of land degradation according to Hardin’s ‘Tragedy of the Commons’ paper, in which he considers that individual self-interest will result in the abuse of a commonly held resource leading to land degradation (Hardin 1968). It has been reported that overgrazing in communal farmed areas is greater than in commercially farmed areas (Archer et al. 1989). Recently, however, some authors have argued that this is not always the case and that the communal areas do not differ from commercial farms in vegetation and soil parameters, while rainfall is the main driving force leading to differences in vegetation productivity in arid lands (Ward et al. 1998). A detailed study of Simpson et al. (2001), evaluating historic documentary sources of grazing pressures, revealed that communal lands in Iceland had regulatory mechanisms to prevent overgrazing from at least the 1200s AD and suggest that there was sufficient biomass to support the numbers of domestic livestock indicated from historic sources. Similarly, land use regulations have been in place in common lands since the Middle Ages in Spain, such as “La Mesta” in Castilla and “Casa de Ganaderos de Zaragoza” and other sheep producers associations, whose mission was the administrative and judicial role to defend shepherds’ rights.

{xtypo_alert}Editor's note 14Jun2012: Text source D211, section 3.2.2{/xtypo_alert}

Drivers of LEDD in grazing land in Greece are mainly related to social, economic and political factors, policies such as the Common Agricultural Policy (CAP) and tourism development.

Overgrazing and under grazing

Overgrazing occurs when the number of animals grazing the land is more than its grazing capacity (Papanastasis 1998; 2000). Due to differences in the way that various grazing animals collect forage, their impact on vegetation and biodiversity loss is different (Rook et al. 2004). As animals graze, they remove parts of plants or whole plants. Removal is selective with the most palatable species eaten first in preference to less palatable ones, which eventually dominate the grazed area. This is the last stage of vegetation degradation (Papanastasis 2008). Furthermore, as animals move around they trample the soil with their hooves, exerting pressure and resulting in soil compaction which leads to reduction of soil infiltration rates causing higher surface water runoff.  Under-grazing occurs when the number of animals grazing the land is less than its capacity. Under such conditions in dryland areas, highly flammable biomass remains on the ground, favouring wildfires which also lead to land degradation.  

Continuous and intensive grazing has been taking place in Greece for millennia.  Overgrazing is considered the main desertification cause for most parts of the country (Yassoglou 1989).  In previous decades, a gradual degradation of the mountainous and hilly grasslands of Greece took place due to overgrazing in some areas and under grazing in others. These two opposite causes are mainly attributed to depopulation of marginal rural areas (e.g. remote mountain areas, highly degraded areas, adverse climatic conditions), and European policies (CAP). Under grazing, and consequent development of scrub, appear to threaten grazing lands more than overgrazing. Reduced grazing levels on the mountain pastures of Greece have allowed scrub and other unpalatable species to develop, reducing the grazing capacity of these areas by 25 percent. Nationally, 40 percent of all mountain pastures (including pasture, wooded pasture and shrub) are under-grazed (Alexandris 1985). Under grazed lands may also result in a loss of biodiversity (Papanastasis 2008).

As Figure 1 shows, overgrazing is associated with several environmental and socio-economic characteristics (Papanastasis 2004). The amount of biomass produced or left at the end of the grazing period, plant cover and species composition are important vegetation indicators (Papanastasis et al. 2003). Usually, when the land is overgrazed, the plant species remaining are undesirable for animals.  Soil and climatic characteristics and temperature all affect vegetation and therefore the carrying capacity of grazing land. There is a direct relationship between soil depth (Papanastasis 1994) or the amount of rock fragment content on the soil surface (Alexandris et al. 1997) and herbage production in pastures.

Figure 1. Important environmental and socio-economic characteristics associated with overgrazing. Source: (Papanastasis 2004)

Continuous grazing during the whole year is more detrimental to species composition than a seasonal or rotational grazing system (Sternberg et al. 2000). Combining overgrazing with wildfires can be more detrimental than either of the two causes of degradation alone. The distribution of road infrastructure also affects grazing pressure.  Areas which are easily accessible by road tend to be grazed more intensively than more remote areas. Furthermore, grazing land situated near watering points or animal sheds tends to be more intensively grazed than land situated further away (Ghossoub 2003).

The socio-economic characteristics that affect the state of grazing lands, such as EU subsidies, local traditions, land tenure (private, state or communal pastures), alternative income sources and legal systems related to the use of pastures, are interrelated with several physical characteristics (land productivity) as well as management factors (number and type of animals, grazing system etcetera) (Figure 2) (Papanastasis 2004).

Figure 2. Soil erosion risk  of an area burned in 2007 in Greece (Aliveri, Evia Greece). Source: (Kosmas et al. 2007).

Overgrazing is a serious problem for most of the mountainous and hilly areas of Crete and is caused mainly by the type of grazing system (Stefanakis 2006) and stocking density. Overgrazing is especially important in the areas of the Psilorites and Asterousia mountains (the LEDDRA study site) (Papanastasis et al. 2006), and the Sfakia region, as a large number of animals is concentrated in those areas. Overgrazing results in high erosion rates, leads to the disappearance of important plant species and the expansion of species which are unpalatable to animals. Pastures in the upper mountainous zone either receive large numbers of animals during the summer period, or they are under grazed due to a lack of infrastructure (roads and drinking water for animals).   

Studies on overgrazing in the Psilorites Mountains have shown that in phryganic lands, overgrazing favoured phryganic species at the expense of the herbaceous vegetation. In the opposite case, in grasslands, overgrazing affected negatively both herbaceous and woody species because the latter are desirable to animals (Papanastasis et al. 2006).

Forest fires

Forest fires in Greece constitute a serious threat of land degradation. During the last 40 years, the number of forest fires has rapidly increased. Fires have become frequent in pine-dominated forests and in pastures. Most fires started by people, either through carelessness or as a management tool to eradicate unpalatable vegetation. The majority of fires occur in areas with high xerothermic indices and moisture deficits. Soil dryness and wind speed are the principal factors of fire evolution. According to the Greek Ministry of Environment, the average rate of burned areas ranged from 44108 to 52417 ha/year in the last three decades.   

Wildfires set by shepherds to control undesirable growth of vegetation is a common practice in many areas of Greece.  Although Mediterranean vegetation is well adapted to fire and usually regenerates soon after burning, it can be destroyed if burning is combined with grazing. Several studies have shown that the combination of wildfires and grazing are the main cause of rangeland degradation and desertification (Arianoutsou-Faraggitaki 1985; Margaris and Koutsidou 1995; Pantis and Mardiris 1992; Papanastasis et al. 1990 Vokou et al. 1986).

Approximately 90 percent of the areas burned every year are areas largely susceptible to soil erosion and land desertification due to shallow soil depth and steep slopes. A typical example of high land sensitivity to soil erosion and desertification is shown in Figure 3 (Aliveri, Evia, Greece).  Soils are mainly characterized as subjected to high (red) or moderate (orange) erosion risk. In addition, land desertification risk is predominantly high (purple or red) or moderate (all colours except green).

Figure 3. Land desertification risk of an area burned in 2007 in Greece (Aliveri, Evia Greece). Source: (Kosmas et al. 2007).

Fire in grazing land, as an environmental concern for forest managers, appeared mostly in the second half of the past century (Pausas and Vallejo 1999). Up to this period, reforestation in these areas was conducted for preventing flooding of lowland, for wood production, and for promotion of rural employment. After the expansion of wildfires, forest managers developed strategies for fire prevention in order to abridge the degradation of grazing lands. Measures include: early warning systems for fire ignition; infrastructure for combating forest fires; the national cadastral plan for forests and forested areas.

The Common Agricultural Policy (CAP)

In the early 1980s, the EU began to subsidise livestock farming (goats and sheep) in order to offer financial support to traditional livestock farmers. The Common Agricultural Policy, through its structural policies, provides an adequate income to farmers, contributing to the development of regional economies and the maintenance of landscapes, particularly in less favoured areas. In addition, subsidies allocated under the CAP accelerate the intensification of husbandry (Wilson and Juntti 2005). Higher farm prices under CAP encourage farmers to keep larger numbers of animals in degraded areas. The number of sheep and goats in Greece has doubled in the last three decades as a result of subsidy allocation, while the number of cows has decreased.

The Greek Government has encouraged livestock farming, according to the grazing-capacity of each region, but without setting rules and prerequisites for the sustainable management of livestock farming (e.g. for the creation of infrastructure for supporting professional livestock farmers, protecting grazing lands and the natural environment) (Tsimpidis 2008). This uncontrolled allocation of subsidies does not comply with national and international legislation for the protection of forests and natural habitats. However, it brought about the creation of very large herds which required extensive areas of grazing land, far exceeding the grazing capacity of many regions. Local authorities also became involved in this uncontrolled financing and management, by renting public areas as grazing lands to livestock breeders. Also, forests have been rented as grazing-lands, as have areas that have either been proposed for protection within the framework of the network of European protected areas (NATURA 2000), as well as areas being protected by international environmental conventions. As a result, this type of livestock farming developed rapidly in many parts of the country (Tsimpidis 2008). This problem was most acute in the Eastern Aegean islands and in Crete.

EU production subsidies are important in supporting farm incomes, and are sometimes greater than the income achieved from livestock production.  Farmers try to maximise their farm income, so their land management decisions are directed towards maintaining the number of animals that can assure higher income. But high animal density is a crucial factor of land degradation, leading to vegetation degradation and, in turn, to soil compaction and erosion. Overgrazing by thousands of sheep and goats is the main contributory factor to the desertification of mountainous areas of Greece

The animal population in Crete, mainly sheep and goats, is higher than the carrying capacity of the land. It is estimated that 1,500,000 sheep and goats graze on 55 percent of Cretan land, eliminating all edible vegetation in their desperate struggle to find food.

Tourism development

In the last few decades, tourism in Greece has increased significantly. New developments, mass tourism, urbanisation and over-exploitation of water resources has led to a progressive decline in traditional husbandry. In previous years, approximately 12 million overnight stays of foreign and national visitors in hotels and rented apartments have been recorded. Crete is one of the most well developed tourist destinations in Greece, receiving more than 2.5 million tourists every year.  

Tourism development motivates farmers to expand their livestock activities into parallel activities such as agri-tourism. In 1967, a national action plan divided Greece into zones for tourism development. The north of Crete was designated as a high priority area for tourism development and this sparked a building boom in the area.  Due to the high numbers of tourists, demand of agricultural products increased considerably. Under these circumstances, farmers tended to expand their livestock operations in order to provide the required quantities of high quality products, particularly important during the height of the tourist season. As a result, more people became engaged in agricultural activities and migration from rural to urban areas was reduced.

Different EU programmes and funds have been used to promote the economic development of rural areas through diversification of local economies and support for bottom-up initiatives. Young farmers have been financially supported by European and National funds, such as the 3rd CSF Regional Operational Programme and the LEADER programme, which is implemented by the national OPAAH Integrated Rural Development Programme. These support programmes have prompted many young farmers to organise their activities on a more professional basis and follow new tourism trends such as agri-tourism. As a result of these drivers, pressure on grazing lands has continued to increase, as the nutritional demands of larger herds of livestock and higher production levels need to be met.

{xtypo_alert}Editor's note 14Jun2012: Text source D211, section 3.2.4{/xtypo_alert}

One of the most important direct drivers of LEDD in grazing land in the Central Pyrenees is the change in traditional land use. The traditional land-uses practiced for centuries have disappeared to a large extent, just as in many other European mountain areas (Taillefumier and Piégay 2003; Lasanta et al. 2005). One of the consequences is the loss of productivity and biodiversity caused by shrub encroachment in abandoned grasslands. The impact of shrub encroachment on these landscapes is an important issue for land managers and land policy makers, but the rate and dynamics of shrub encroachment occurring in semi-natural grasslands are not well known in terms of land-use changes and climate change (Bartolomé et al. 2005). Consequently, a better understanding of the land-use change and its consequences is essential for the comprehension of mountain landscape dynamics and maintenance of biodiversity, the cultural heritage, and agricultural and pastoral production (Lasanta et al. 2006; Mottet et al. 2006).

Multiple factors (indirect drivers) are responsible for these land use changes resulting in changes in demography and socio-economic conditions (García-Ruiz and Lasanta 1990). The main indirect drivers leading to these socio-economic changes are: the movement of people to cities and industrial regions; agricultural mechanisation (less accessible areas were abandoned); and the development of synthetic fibres which reduced the value of wool and wool products. Extensive grazing is expensive in terms of production because it is labour-intensive. Every day, shepherds must look after their flocks. This limits the labour force and reduces the availability of experienced shepherds. The ovine is replaced by bovine because cattle production requires less in terms of human resources and cattle are better adapted to indoor production systems. As a result, some areas moved to intensive production of fodder for cows, and the more remote, less productive areas were abandoned (Lasanta 1989). The loss of agricultural soil due to tourist infrastructure is another of the causes of less forage being available for livestock, reducing the capacity of the area to feed animals during winter.

Other important indirect drivers are demographic changes, mainly characterised by an aging and decreasing population, resulting in smaller families with weaker social bonds who are unable to maintain the labour requirements for extensive practices such as transhumance, which in turn has caused the disappearance of transhumance and prompted a crisis in the sheep sector, leading to shrub encroachment (García-Ruiz et al. 1996). Alternatively, tourist development also acts as indirect drivers, affecting traditional land use.

There has been significant development of tourist infrastructures in the Central Pyrenees associated with the construction of five alpine ski resorts, between 1965 and 1976. Comparisons between municipalities with ski resorts and those without revealed a population increase of 60.4 percent between 1970 and 2008 for those municipalities with ski resorts, while the municipalities without ski resorts have lost 26.6 percent of their population in the same period (Lasanta 2010). The number of farms has declined 48 percent in municipalities with ski resorts and 22 percent in municipalities without ski resorts in the same period (1970-2008) (Lasanta 2010). A loss of 43 percent of livestock was also reported for the same period in municipalities with ski resorts, as opposed to an increase in livestock of 31.8 percent in municipalities without ski resorts. Competition between stockbreeding and tourist development has been reported in the Pyrenees in the High Esera Valley (Laguna & Lasanta 2003), where movement of workers from the primary sector into tourism was observed. The number of UGM (large livestock unit) declined in the High Esera Valley from 5335 in 1970 to 3758 in 1999, in parallel with the reduction in the number of farms from 312 in 1965 to 127 in 2000. Conversely, the number of tourist beds in hotels, auberges and camp sites increased from 344 in 1960 to 17073 in 1999.

Direct and indirect drivers interact. In Spain three important events have shaped socio-economic developments and influenced the landscape in the last 500 years (Puigdefábregas and Mendizabal 1998; Alados et al. 2011), acting as direct and indirect drivers of LEDD:

• The first occurred between the 16th and 17th centuries coinciding with the establishment of Christian rule, which favoured the expansion of rain-fed agriculture; and the colonisation of America, which increased the demand for products to meet population demand.
• The growth of the population led to the second period in the 18th century (Dupre Ollivier 1990), which resulted in the overpopulation of rural areas until the first half of 20th century; the encroachment of agriculture onto rangelands and increases in livestock numbers.
• The third phase occurred in the 1960s with the industrialization of towns and the migration of rural people into cities.

{xtypo_alert}Editor's note 14Jun2012: Text source D211, section 3.2.3{/xtypo_alert}

Table 1 below lists the key direct and indirect drivers of LEDD issues which occur in the Middle Atlas region and Timahdit study site within Morocco.  

Table 1. Direct and indirect drivers of LEDD in the Middle Atlas and Timahdit Region of Morocco

Source: (Adapted from Millennium Ecosystem Assessment 2003)

The area of the Ait Arfa du Guigou devoted to agriculture has increased as a result of suitable environmental conditions for the production of crops such as potatoes, onion, and horticulture (apples and cherries). Agricultural expansion has also led to a break down in the pattern of transhumance, and has obliged herdsmen to settle in the summer rangelands.  Surveys were used to assess the history of the settlement of herdsmen on Ait Beni Yacoub rangelands. The results indicated that settling started early in the century, but it was during the period 1960-1970 that the first selection of land for settlement was observed. Even though settlements on rangelands were forbidden by law, to conserve natural resources, herdsmen have increasingly continued to construct camps on rangelands over the past 30 years.  The settlement of herders has had a negative impact on rangeland resources, as it has lengthened the grazing season and increased grazing pressure.  Grazing pressure reported for these rangelands varies between 1.6 and 6.3 ewes per hectare depending on the grazing location (Laroussi 2000). The consequences of these changes are (Belkhou and Azzouzi 2002)

• Fragmentation in the vegetation cover of rangelands
• A significant increase in bare soil and an associated increase in erosion
• An increase in invader species such as Euphorbia nicacensis
• An increase in annuals species abundance
• A decrease in perennial species
• Degradation of Genista pseudopilosa mattoral
• A decrease in the vigour of low shrubs, especially Genista Pseudopilosa.  

Genista pseudopilosa is shrub of 20 to 50 cm high that plays a major role in the preservation of rangelands since it acts as facilitator for other perennial grass species, which grow and drop seeds within it.