When considering the biodiversity of Madagascar it is important to think about the importance of biodiversity, what it is and why it should be protected for the good of our planet: Biodiversity is the variety of plant and animal life on Earth. However insignificant they may appear, every species has a role to play in ecosystem productivity to ensure natural sustainability. Having a healthy biodiversity on our planet contributes to formation of good soil, protection of water resources, climate stability and pollution breakdown as well as providing us with food, wood and medicinal resources. 70% of pharmaceutical drugs are based on plant structures and around 900 of the plant species in Madagascar are used in this way. Trees are “rain factories”, releasing water vapour into the air when they transpire which results in precipitation. Deforestation interferes with this process. Insects that pollinate plants are currently saving vast amounts of money for global agriculture and extinction of these species would result in an 8% increase in the industry’s costs. In short, we need an extensive biodiversity on Earth in order to survive.
Unfortunately, in Madagascar, there are numerous threats to the plant and animal life that is so unique and has evolved over millions of years. These threats come from human interference in living processes and with a combination of deforestation, over-exploitation of resources and introduction of alien species there has been rapid degradation in the island’s natural environment. Since humans first appeared on the island about 2350 years ago around 90% of Madagascar’s original forest vegetation has been destroyed. Between 1950 and 2000 alone it is suggested that about 40% of the forest cover was lost.
There has long been a culture of “slash and burn” in Madagascar (or Tavy, as it is called locally). Local people convert the rainforests into rice fields by cutting down acres of forest and burning it before planting rice. Two years of crop growth is followed by between four and six years of lying fallow before replanting occurs. After this process has been repeated a few times, the soil has lost all nutrients so alien grasses and scrub takes over the land. On sloping land, the new vegetation is not strong enough to anchor the soil so landslides occur and erosion becomes an issue. “Slash and burn” farming has a long cultural and spiritual significance for the Malagasy people who need to clear the land in this way in order to feed their families with little or no thought for the future.
As well as Tavy, there is a financial incentive for deforestation of the rainforest areas in the east where logging for the high value hardwoods has become a problem. Although logging is illegal in these protected areas, the prospect of raising profits of around $2000 a ton for ebony and rosewood has resulted in many instances of flouting the law. Charcoal production has also resulted in the cutting down of the spiny forests.
Fires are often laid to clear land for pasture which then accidentally spreads to surrounding areas. Bushfires often spread out of control and up to a third of the island is burnt annually. These result in the destruction of endemic plant and animal life, damaged and unproductive soil as well as soil erosion. These uncontrollable fires cause numerous problems for local people whose homes and livelihoods are threatened. Dried up water sources, silted up rice fields and air pollution are just some of the issues that they encounter.