Agriculture in Madagascar is predominantly rain-fed, meaning food-security is highly susceptible to inconsistent rainfall, as discussed in Part I. In a recent study, it has been revealed that Madagascan farmers have adopted land-use change as a direct adaptive strategy to help offset poor crop yields. By clearing forest and expanding cropland, farmers attempt to boost the chances of a successful harvest. Yet, Madagascar’s unique forests are a regional and global hub of biodiversity, so forest clearance is a difficult and contested issue. Part II of this article will discuss the link between rainfall, agriculture and land-use change.
The ‘eighth continent’
Madagascar covers only 1% of the Earth’s terrestrial surface, but accounts for around 5% of the world’s total biodiversity. Furthermore, around 90% of the species found on the island are found nowhere else on earth. It is thought that natural variations in Madagascar’s climate, combined with its unique geography, shaped its distinctive flora and fauna. Evolutionary responses to Madagascar’s unpredictable rainfall and varied landscape can be seen in the extreme species variation, in which organisms fill an unusual number of ecological niches across the island. Madagascar’s long geographic separation, fostered the development of its highly adapted and endemic biodiversity, isolated from human influence. However, anthropogenic direct impacts on Madagascar’s native biota has been well documented. Although humans took a little while to colonise, the arrival of settlers from (likely) Southeast Asia in the first century AD coincided with the near immediate mass extinction of almost all its megafauna. Madagascar’s highly specialised biodiversity is immensely susceptible to anthropogenic change.
‘Kowalski, analysis.’
Land-use change for agriculture remains the primary driver for deforestation worldwide, with 80% of cleared land in use for agricultural purposes. In Madagascar, there is now evidence for drought-driven deforestation. A study found that deforestation increased 7.6% on average in years of comparative drought and as much as 17% in its arid and semi-arid regions. Madagascar is now thought to have lost nearly half its forests in only half a century, and contains the highest number of threatened species in Africa. Yet, forest habitats are more resilient to short-term changes in rainfall patterns than cropland and can provide natural capital, acting as safety nets for rural communities to mitigate against extreme weather events. Furthermore, they are crucial for maintaining biodiversity and easing climate change through carbon storage. Perhaps slightly ironically then, adaptive measures taken by farmers to mitigate against environmental change are further perpetuating the long-term issue.
Undoubtedly the economic and social costs of droughts and deforestation are considerable and increasing. However, the link between deforestation and drought is not linear. Land-use change is a short term solution to boost yields, but in the long-term, recurring droughts often trigger ‘risk-averse’ farmers to lower their exposure to rainfall dependence by reducing cropland, diversifying their products or migrating. Thus, rainfall is influential in determining the composition and distribution of forests both directly and indirectly. If droughts and deforestation in Madagascar are agricultural problems, then they require agricultural fixes. Policy based solutions and economic incentives, such as legislative insurance programs for farmers (supported by global climate finance if needed), would provide safety-nets in the event of droughts and help reduce pressure for land-clearance. Investment in infrastructure, such as improved road networks and water pipelines could facilitate the movement of water and goods between regions of the island. Finally, continued groundwater research, for example using remote sensing, could help find solutions to limit the reliance on rain as a determinant for water-security.
Groundwater difficulty
Much of the reason for farmers reliance on rain-water is much of Madagascar’s groundwater is hard to access. This is due to being located in ‘regions with complex hydrological structures which are prone to geochemical contamination’, including saline and fluoride impurities – many of Madagascar’s largest aquifers are near the coast and susceptible to salt-water penetration. Groundwater withdrawals are important for the bulk of the African continent’s population and are especially important in arid regions, where groundwater is often the only reliable source of fresh-water year-round. However, due to a combination of: limited scientific knowledge and complex hydrogeology, plus restricted economic investment and infrastructural constraints, most communities in Madagascar are unable to access safe groundwater.
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| Rain-fed rice paddies in the central highlands |
The ‘eighth continent’
Madagascar covers only 1% of the Earth’s terrestrial surface, but accounts for around 5% of the world’s total biodiversity. Furthermore, around 90% of the species found on the island are found nowhere else on earth. It is thought that natural variations in Madagascar’s climate, combined with its unique geography, shaped its distinctive flora and fauna. Evolutionary responses to Madagascar’s unpredictable rainfall and varied landscape can be seen in the extreme species variation, in which organisms fill an unusual number of ecological niches across the island. Madagascar’s long geographic separation, fostered the development of its highly adapted and endemic biodiversity, isolated from human influence. However, anthropogenic direct impacts on Madagascar’s native biota has been well documented. Although humans took a little while to colonise, the arrival of settlers from (likely) Southeast Asia in the first century AD coincided with the near immediate mass extinction of almost all its megafauna. Madagascar’s highly specialised biodiversity is immensely susceptible to anthropogenic change.
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| The biodiversity of Madagascar |
‘Kowalski, analysis.’
Land-use change for agriculture remains the primary driver for deforestation worldwide, with 80% of cleared land in use for agricultural purposes. In Madagascar, there is now evidence for drought-driven deforestation. A study found that deforestation increased 7.6% on average in years of comparative drought and as much as 17% in its arid and semi-arid regions. Madagascar is now thought to have lost nearly half its forests in only half a century, and contains the highest number of threatened species in Africa. Yet, forest habitats are more resilient to short-term changes in rainfall patterns than cropland and can provide natural capital, acting as safety nets for rural communities to mitigate against extreme weather events. Furthermore, they are crucial for maintaining biodiversity and easing climate change through carbon storage. Perhaps slightly ironically then, adaptive measures taken by farmers to mitigate against environmental change are further perpetuating the long-term issue.
Undoubtedly the economic and social costs of droughts and deforestation are considerable and increasing. However, the link between deforestation and drought is not linear. Land-use change is a short term solution to boost yields, but in the long-term, recurring droughts often trigger ‘risk-averse’ farmers to lower their exposure to rainfall dependence by reducing cropland, diversifying their products or migrating. Thus, rainfall is influential in determining the composition and distribution of forests both directly and indirectly. If droughts and deforestation in Madagascar are agricultural problems, then they require agricultural fixes. Policy based solutions and economic incentives, such as legislative insurance programs for farmers (supported by global climate finance if needed), would provide safety-nets in the event of droughts and help reduce pressure for land-clearance. Investment in infrastructure, such as improved road networks and water pipelines could facilitate the movement of water and goods between regions of the island. Finally, continued groundwater research, for example using remote sensing, could help find solutions to limit the reliance on rain as a determinant for water-security.
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