Grazing land
Drivers of LEDD in grazing land: general
Authors: Conceptión Alados, Erea Paz, Frederico Filliat, Maite GartziaEditor's note 14Jun2012: Text source D211, section 3.2.
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
Type of Driver | Examples |
Direct drivers of LEDD | |
Changes in local land use and cover | Land abandonment; unsustainable land management practices |
Species introduction or removal |
Introduction of new commercial breeds less adapted to local natural conditions |
Technology adaptation and use | Mechanisation and motorization (use of tractors and tracks to carry water and feedstuff to remote areas) |
External inputs | Importation of feeds |
Harvest and resource consumption | Increasing or changing global food demand |
Climate change | Increased frequency of extreme weather events |
Other natural, physical and biological drivers | Loss of local knowledge of traditional rangeland management techniques |
Indirect drivers of LEDD |
|
Demographics | Changes in population structure and spatial distribution such as rural out-migration of young people; ageing populations in coastal areas etc. |
Economic | Changes in national and per capita income; international trade flows; changes in global, regional and local market prices; macroeconomic policy; strategies to alleviate drought threats |
Socio-political | Democratization; changes in the role of women; changes in civil society such as the loss of traditional transhumance patterns etc. |
Science and technology |
Adoption of new technologies including biotechnology and information and communication technologies; changes in research funding; |
Cultural and religious | Social norms surrounding consumption; materialism; changing religious practices etc. |
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.