Desertification refers to the process of degradation of economically productive land in dry areas. Desertification has long been recognized as a major environmental and societal problem emerging from a combination of climatic factors and human activities.
Drylands make up 40% of the world land mass and sustaining 44% of the world’s food production systems as well as 50% of the world’s livestock. According to UNCCD (United Nations Convention to Combat Desertification) every year around 12 million hectares of productive land is lost worldwide due to drought and desertification thus hampering the life-supporting systems sustained by these lands.
Pakistan is mainly a dryland country with around 80% of the land being arid or semi-arid supporting the livelihoods of around two-thirds of the country’s population. However due to rapid land degradation and desertification largely arising from human activities, we are losing this vital non-renewable resource.
The challenge of desertification
In recent decades, desertification has largely been driven by human interventions posing serious threats to several populations across the globe. Desertification is a self-accelerating process involving a range of inter-connected phenomena many of which are both causative and consequential.
Deforestation: One of the most significant factors directly associated with desertification is the loss of vegetation and forest cover. Pakistan’s forest cover is only 3-4% of the total land mass instead of the required 20-25%. Indiscriminate cutting of forests by local communities, timber mafia and property builders has aggravated the problem of desertification. Vegetation stabilizes soil by providing cover and withholding of sediments by roots. Deforestation exposes the soil to the effects of soil-degrading factors such as wind and water erosion. It also reduces the resistance against water logging and salinity, causes the loss of productive topsoil, loss of biodiversity and also contributes to global warming.
Grazing pressure: Increasing and unsystematic livestock grazing has devastated ecosystems in various parts of the country. Loss of shrubs and woodlands in the Southwestern Mountains and other dryland areas has caused tremendous land degradation resulting in the loss of soil fertility and increased soil erosion.
Climatic factors: Climatic factors such as drought and flooding also contribute to the problem of desertification. Floods cause a loss of vegetation, crops and fertile topsoil. Drought has a very significant impact in arid and semi-arid areas. Pakistan drylands are subject to periodic and prolonged droughts which have accentuated the problem of desertification particularly in fragile ecosystems. Drought on one hand reduces the recharge of groundwater aquifers and on the other hand causes the loss of vegetation which promotes desertification.
Water logging and salinity: Water logging, i.e. the saturation of soil with water, and salinity, i.e. excess of soluble salts in soil solution are also a major causative factor of land degradation in Pakistan. Water logging is more prevalent in the irrigated areas of Punjab, Sindh and Baluchistan mainly due to improper use of irrigation water. Around 11 million hectares of the land is water logged with water table depth of only 5-10 feet.
Salinity is associated with natural processes as well as to the irrigation activities affecting around 6 million hectares of total land mass of Pakistan. Water logging and salinity render a fertile land barren thus hampering the productivity of soil and loss of biodiversity.
Soil erosion: Soil erosion is the loss of soil involving detachment, movement and deposition at a new location. Soil erosion by wind (wind erosion) or water (water erosion) is a significant challenge associated with desertification. Soil erosion results in the loss of productive topsoil thus directly affecting land fertility as well as associated biodiversity.
Wind erosion is common in the arid areas of Punjab, Sindh and Baluchistan affecting around 3-5 million hectares of land and is responsible for 28% of the total soil loss. Dust storms not only erode a substantial amount of soil from a dryland but also create health and pollution issues in the deposition areas.
Water erosion is worsened by deforestation, overgrazing and poor watershed management. It has become a major ecological hazard in Pakistan. An estimated 40 million tons of sediments are annually introduced in the Indus river basin. This increased sedimentation of water bodies has reduced the water storage capacity of major reservoirs, affected aquatic biodiversity and is responsible for increase in the risk and intensity of floods. About 11.2 million hectares of land in Pakistan is affected by water erosion. Northern mountain regions with relatively thick forest cover protect soil from erosion while maximum runoff overloaded with eroded sediments is generated from deforested and irrigated lands.
Degradation of rangelands: Rangeland refers to a vast area (usually an open land) used by livestock for grazing and constitutes around 60% of the total land mass of Pakistan. These lands are naturally fragile ecosystems highly vulnerable to degradation. Baluchistan is around 79% rangeland and livestock rearing is the predominant occupation of people in the province. Lack of integrated grazing management practices, recurrent drought, and erosion are the main factors behind rangeland degradation in Pakistan threatening the sustainability of this significant resource.
Loss of biodiversity: Biodiversity loss is a serious global and regional concern. Every year world loses around 27,000 species and with it valuable genetic resources. Desertification is one of the major threats to biodiversity by affecting soil biota as well as allied species. Drylands provide an important habitat for several species of mammals and birds which may suffer a threat of extinction with ongoing desertification.
Agricultural practices: Pakistan is primarily an agricultural country and around 60-70% of the population is directly or indirectly linked to the agricultural farming. In addition to rain-fed areas, there is an extensive irrigation system as well. However, mismanagement of irrigation system and agricultural practices has contributed significantly to the problem of land degradation and desertification. Extensive and continued cropping without nutrient replenishment has negative effects on soil fertility. Artificial fertilizers are used for maintaining fertility of soil but the high costs of fertilizers limit their use. Moreover, fertilizer application is almost always more generalized without a pre-testing of soil for required minerals leading to nutrient imbalance and reduction in soil fertility.
Increased cultivation leads to increased irrigation generating problems like excessive use of groundwater, water pollution, soil erosion, salinity and water logging all contributing to desertification. Another problem is expansion of cultivated lands in drylands to meet the increasing food demand thus conferring the risk of degradation due to alterations in ecosystem.
Food insecurity and poverty: Fertile soil is the most significant, non-renewable geo-resource. Loss of soil productivity and its consequences in the form of loss of livelihood, food insecurity, hunger and poverty are one of the biggest threats associated with land degradation and desertification. According to IPCC (Intergovernmental Panel on Climate Change) and MDG (Millennium Development Goals) food security is one of the biggest challenges faced by global population and is likely to worsen with time if not taken seriously. Pakistan’s economy faces a direct loss of billions of rupees due to reduction in agricultural output as a result of land degradation and desertification.
Desertification has inverse relationship with food security and a direct link with food prices thus conferring vulnerable populations to the increased menace of hunger and poverty. An estimated 1.2 billion people who inhabit drylands are below poverty line. At present, land degradation directly affects 74% of the poor worldwide. Continuing trends will entrench more population in poverty and food insecurity ultimately driving more migrations and conflicts in turn threatening the global security.
Human population growth: Primary driving factor behind this ecological issue is the increasing pressure on natural resources due to ever-increasing human population coupled with lack of sustainable and wise land use management. Basic human needs such as food and space are directly linked to land usage and are being negatively affected by desertification making this planet a hostile place for future generations to live in.
Natural ecosystems have a threshold beyond which damage becomes irreversible warranting the significance of timely efforts. To ensure food and livelihood security, populations will have to adopt measures to conserve and enhance natural resources. Desertification has long been recognized as a challenge by international community evident from the 1992 Rio Earth Summit which identified it as a major challenge to sustainable development along with climate change and loss of biodiversity. United Nations Convention to Combat Desertification (UNCCD) was established in 1994 with objectives seeking “to improve land productivity, to restore (or preserve) land, to establish more efficient water usage and to introduce sustainable development in the affected areas and more generally, improve the living conditions of those populations affected by drought and desertification”. With the assistance of United Nations Development Program (UNDP) and Global Environment Facility (GEF), Ministry of Environment, Pakistan launched a project “Sustainable Land Management to Combat Desertification in Pakistan“ to address the issues pertaining to land degradation and desertification. Following strategies can be taken into consideration to combat this growing threat.
Awareness activities: Awareness or promotional activities are the first step to be taken for combatting desertification. June 17 has been declared as the World Day to Combat Desertification and Drought since December 1994 by UN General Assembly to sensitize policymakers and public about the challenge. Unfortunately we do not observe effective awareness campaigns against this menace in Pakistan. Awareness regarding its implications on economy, food and society and the approaches to manage the issue needs an extensive coverage. Promotional activities may involve education through electronic and print media; distribution of educational materials in educational institutes; awareness workshops and communication with and technical training of direct land users. Sensitization and information is important because only a well-oriented population can respond positively to the mitigation efforts.
Land use management: Sustainable and integrated land use management is critical to address arid and semiarid lands and a key to combat desertification. First of all there is a need for the establishment of monitoring and tracking system so that appropriate strategies can be devised. Land use management practices must be based on the knowledge of land capacity and the rate of soil depletion. Land use management could involve agroforestry; game ranching of animal species better adapted to arid conditions than livestock; integrated farming techniques; land reforms etc. Lessons can be learned from strategies adopted in other countries with similar challenges. Due to rapid increase in population, demand of products is acute and so are the symptoms associated with the disruption of ecological services. Viable approach is to diagnose the issue and devise long-term solutions than focusing on acute problems.
Reforestation: Reforestation is one of the most effective and foremost strategies to combat desertification. As a consequence of reforestation campaigns, many desertification-prone area of the world are responding positively to address the threat. For instance, our immediate neighbors China and India have turned themselves from forest-losing to the forest-gaining regions through massive replantation efforts. With increasing requirement for agriculture, it has become difficult to reverse the conversion of forest land into the cultivated land. However, adoption of agroforestry practices offers a viable solution towards restoring forest cover in these areas.
Reclamation of land: Land degradation is not necessarily permanent, and at many places, it has a potential to be reversed. Therefore, efforts must be done for the restoration and reclamation of affected areas such as Baluchistan rangelands before the damage becomes irreversible.
Urban planning: The factors directly causative of desertification are themselves the function of population density. Appropriate urban planning and wise partitioning of resources is therefore required to manage the stress on land resources.
Research opportunities: Research aimed at finding out innovative approaches and technical improvements to the existing practices must be encouraged. Owing to the diverse nature of the issue involving multiple social, economic, demographic, political and ecological aspects, a multidisciplinary approach based on scientific principles holds the potential to offer more promising solutions. Therefore, research promotion must constitute a compulsory part of long-term planning.
Sustainable agricultural practices: A lot of research has been done worldwide to improve agricultural practices and to enhance crop yields in a manner least stressful to natural resources. Translation of that research in Pakistan after initial trials, availability of low price fertilizers and an easy access to soil testing laboratories and other technical assistance facilities are among the key factors to conserve soil fertility and improve productivity. Expansion of agricultural farming to more fragile drylands should be avoided by improving crop yield per unit area. Selection of drought-resistant varieties could help manage water budget of marginal lands in particular.
Economic growth costs us long-term losses to the ecosystem. We need to develop and adopt systems that do not compromise ecosystem integrity. Our economy and prosperity is based on the primary productivity of our land. Neglecting this serious issue will limit our survival, therefore we need to protect and conserve our soil capital. Likewise, keeping the increasing prevalence of hunger and poverty in mind, power corridors and policy makers need to realize that “building fences around their prosperity will not work”.