Deforestation in Madagascar

Deforestation by life in Madagascar by human intervention first made an impact on its highland forests as early as AD 600 in the establishment of swidden fields by Indonesian settlers.[11] The creation of swidden fields is a subsistence method of agriculture that has been practised by humans across the globe for over 12000 years by means of a slash and burn technique that clears an area in preparation for crop growth.[12] An increase in the rate of forest removal was seen around AD 1000 with the introduction of cattle from Africa, compelling Malagasy islanders to expand their grassland grazing areas. Historical records point to the importance that this impact has caused with the disappearance of most of Madagascar’s highland forest by 1600 AD.[13] Attempts to conserve Madagascar’s forests were introduced by French rulers in the establishment of environmental regulations, the earliest being seen in 1881 when Queen Ranavalona II placed a ban on using slash and burn techniques in agriculture.[14] These efforts aimed to protect the future of the countries rainforests, however, it has been estimated that over 80 percent of Madagascar’s original forests are gone with half of this loss occurring since the late 1950s.[14]

Early estimates of deforestation in Madagascar were unreliable until using data taken over a 35-year period from a combination of aerial photography, taken in 1950, and more recently data from satellite imagery available since 1972 were used to clearly see the extent of rainforest cleared in the eastern areas of Madagascar.[15] By 1985, only 50 percent of the 7.6 million hectares that existed in 1950 remained equating to an average deforestation rate of over 111,000 hectares per year[15] and by 2005 the country had seen a total of 854,000 hectares of forest lost since 1990.[14] Since the first evidence of human occupation less than 2000 years ago the island of Madagascar’s population in 2002 had grown to about 12 million people (McConnell, 2002). Agricultural fires, erosion and soil degradation continue to contribute to the degradation of the countries ecological stability impeding forest regrowth[13] and according to recent data taken over the 2001 – 2012 period the rate of forest loss in Madagascar’s has continued to increase.[14]

The primary cause for deforestation in Madagascar is the slash and burn practice. Historically and culturally known as “Tavy,” the process involves setting vegetation alight after being cut down, creating potential land for rice cultivations.[16] Coupled with the establishment of rural communities who undertake farming,[17] hectares of forest are lost to agriculture.

Since the 1940s, the population in Madagascar has rapidly increased, putting pressure on the land available for housing and farming. Thousands of hectares of rainforest have been cut down in order to provide for the increased population.

As 40% of Madagascar’s rural population lives in poverty and has little to no access to electricity, they have to resort to using fuelwood for completing daily tasks. Consuming approximately 100 kg of fuelwood monthly, Madagascan households use this energy for cooking, home heating and lighting[18]

Illegal export of rosewood from Marojejy National Park

The Masoala Peninsula, in Madagascar’s east, consists of valuable hardwood timber. Mostly ebony and rosewood, rainforests are degraded in order to satisfy a high demand within the international market.[14][19]

Since its divergence from Africa over 88 million years ago, Madagascar has evolved into an incredibly biodiverse island.[22] Including more than 13000 plants and 700 vertebrates,[22] close to 90% of Madagascar’s species are endemic and are found nowhere else in the world.[23] However, with deforestation depleting key habitats and food resources, over 8000 species are either classified as vulnerable or endangered and some, including 15 species of lemur, have actually gone extinct.[24] Coupled with its geographic isolation thus increasing vulnerability to destruction,[23] deforestation will continue to impact Madagascar’s flora and fauna, increasing rates of extinction.

Deforestation of the Highland Plateau has led to extensive siltation and unstable flows of western rivers.

Like many habitats that undergo deforestation, Madagascar experiences soil erosion, of which can adversely affect river systems and lakes. In the case of Lake Alaotra in Ambatondrazaka area, in the country’s east, deforestation in the hills above has caused heavy erosion, leading to increased sedimentation in the lake. As result, Lake Alaotra has actually decreased in size by approximately 30% in last 40 years. Moreover, the water quality of the lake has suffered, thus reducing the productivity of neighbouring rice cultivations.[25] Soil can also become infertile after vegetation clearing. When plants die or shed their leaves, micro-organisms in soil decompose the leaf litter as they consume it, breaking it down to key nutrients valuable to future plant growth. Should this biomass be removed, there will be no nutrient recycling, reducing soil fertility and reducing plant growth.[23]

Deforestation in Madagascar, as well as other parts of the world, can have an influence on climate. When the forest is cleared, the understorey is left exposed to the sun to a greater extent than before. This increased sunlight reduces soil moisture and increases rates of evapotranspiration in plants, ultimately dehydrating them and stunting growth.[26] At a global level, deforestation is also known to have an effect on carbon dioxide levels in the atmosphere through;

• Slash and Burn Practices: Used primarily to create agricultural land, it involves the logging of forests and burning debris afterwards.[26]
• Disruption of Photosynthesis: Plants absorb atmospheric carbon dioxide, as well water, in order to form their biomass and oxygen.[27] Without plants, carbon dioxide is not absorbed.

It is with the loss of crucial carbon sinks and continuation of slash and burns deforestation that carbon dioxide levels will continue to increase in the atmosphere, ultimately contributing to global warming.[26]

Deforested agricultural countryside in Madagascar

While a key cause of deforestation,[16] agriculture can also be one of its victims. Without vegetation to anchor soil, the chance of erosion increases, sending close to 400 tonnes/ha of sediment into waterways annually.[16] As a result, water quality decreases and coupled with a lack of nutrient cycling due to little biomass, plant productivity is reduced, including valuable rice crops;.[28][29]

As a product of its biodiversity, Madagascar has a vast array of plant species, with 2,300 having medicinal properties that treat many illness, from common ailments to cancers.[30] Should deforestation continue, the pharmaceutical industry will lose a key resource, eventually suffering decreases in profit.[31]

Madagascar possesses a vast array of species, 90% of which are only unique to the island.[29] With deforestation destroying habitats and causing increased extinctions, Madagascar will potentially lose a great tourism asset, eliminating incentive to invest in ectourism operations (such as resorts, recreational facilities, and national parks), thus decreasing long-lasting employment opportunities for local communities.[30]