Habitat loss in rainforests
Occupying about 7% of the earth’s total surface, tropical forests are estimated to contain more than 50% of the world’s terrestrial species. Due to these high levels of biodiversity, the complexity of biological interactions in tropical forests is unequaled in other ecosystems, and therefore also their importance to man.
At the local level, timber and non-timber products from tropical forests support the traditions, livelihoods, and financial well-being of millions of Africans. Tropical forests are also of regional importance, including the protection of river basins and moderating climate.
Finally, as a carbon sink, tropical forests play an important role globally in mitigating adverse effects of anthropogenic climate change, and with 17% of the Earth’s tropical forests, Africa plays an important role globally in efforts to conserve tropical forests.
Despite the importance of tropical forests, their destruction has become synonymous with the rapid loss of biodiversity. Africa had already lost more than 65% of its native tropical forests by 1990; human activities have destroyed an additional,308,000 km2 (an area larger than Italy) between 1990 and 2010
Ethnobotany, as a scientific discipline, studies the relationships between people and plants: how people affect the survival and distribution of plants and how plants influence human behavior and cultures. For instance, local cuisines are shaped by the plant species available, and people cultivate species that consider useful.
The conservation of plant diversity can be helped in several ways.
RECOGNIZE THE IMPORTANCE OF PLANTS FOR THE SUSTAINABILITY OF PEOPLE AND FOR SPIRITUAL PRACTICES
People in East Africa identify and use a large number of plant species that are essential to their well-being. Native plants are used for food, for construction, to treat illnesses in people and livestock, and in many other ways.
Some of the more notable species include White’s ginger (Mondia whitei) and red stinkwood (Prunus africana, VU) for medicine,African teak (Milicia excels, NT) for wood, shea (Vitellaria paradoxa, VU) for foods and cosmetics and African sandalwood (Osyris lanceolate, LC) as a source of fragrance oil.
Some plant species (and sometimes entire ecosystems, such as forests) are appreciated for religious or cultural reasons. Plants or forest areas themselves they are considered sacred, the place of a deity or spirit, with certain rituals performed using those particular plant species or the habitats they occupy. These sacred sites and species are protected by local taboos.
For example, powdered bark of gardenia (Gardenia ternifolia) is not harvested for firewood by Balamogi people of Uganda because it is believed to bring bad luck. Among Kenya’s Mijikenda, sacred forests known as Kaya are protected because people believe that forests are inhabited by spirits and are places of prayer and held as a source of ritual power. It is forbidden to cut trees, graze livestock and cultivate inside the Kaya.
A protective belief holds that cutting down a tree in the Kaya with a machete can result in a machete bouncing off and hurting the woodcutter. Another belief is that food cooked with wood from these sacred forests can cause disease and that a house built with wood from the forest will collapse.
Therefore, more than 50 Kaya, whose size varies from 0. from 3 to 3 km2 and is home to 187 plants, 48 species of birds and 45 species of butterflies enjoyed unofficial protection due to religious and cultural beliefs.
Today, however, the plants and their natural communities that are important to our well-being are threatened. By far the biggest threat is the land use habitat change and conversion to agriculture to produce food for a growing population of people.
The evolution of cultural and spiritual values in East Africa, as well as social and economic pressures also threaten the existence of sacred forests. For example, the place of the coronation of the Paramount Chief of the Balamogiin Uganda was previously protected as a sacred forest by local tradition, but it is today demolished and transformed into gardens by the local populations who no longer follow the old traditions.
Collection of plant species, such as red stinkwood and sandalwood from East Africa, for international markets is also an important threat no longer held at bay by cultural norms.
Fortunately, several species continue to be actively protected by local communities and governments. Traditional healers contribute to conservation by replanting approximately 50% of the medicinal plant species that they consider important for their practice. For the relationship between people and plants to survive, scientific conservation and local tradition must work together.
An example of such collaboration is on display in Uganda Budongo Forest Reserve, where researchers from Budongo Conservation Field Station work with local communities to perfect methods of sustainable management and use of local plants in the region. Losses were particularly severe in Burundi, Benin, and Mozambique, with each country having less than 5% of its original forest cover.
Retaining about half of its original forest cover, the DRC is relatively better, but current deforestation rates in this country are currently the second-highest in the world. Current rates of deforestation are so severe in Equatorial Guinea that this country will lose all its forests in the next 20 years if current trends are continued.
Despite these alarming trends, the destruction continues relentlessly, especially in Ghana and Côte d’Ivoire which saw an increase of 60% and 26%forest loss (the largest increase globally), respectively, between 2017 and 2018. Across Africa, deforestation is currently the dominant driver of forest loss (which caused 77% of total losses over the last decade), followed by agriculture.
Rivers and deltas
Due to our dependence on freshwater, humans have always preferred to live near rivers, streams, and lakes. Consequently, these aquatic environments have been destroyed at a scale at least equal to that of terrestrial environments.
Rivers have taken a particularly hard hit from human activities, being polluted by industries and dammed to ensure a reliable, year-round supply of water for consumption and irrigation, and to generate hydroelectricity. Dam construction holds several negative consequences for biodiversity and people.
Aquatic organisms that cannot survive the altered river conditions downstream (reduced flow and dissolved oxygen, higher temperatures, and increased turbidity) are most vulnerable. For example, a study from South Africa found that native macroinvertebrate populations (often a good indicator of water quality) were reduced by 50%, and some insect orders virtually extirpated following dam construction.
Dams also displace aquatic organisms upstream. In one well-studied example, back flooding of Mozambique’s Massingir Dam facilitate driver substrate changes and the spread of invasive species, which in turn forced sharptooth catfish (Clarias gariepinus, LC), tiger fish (Hydrocynus vittatus, LC), and Nile crocodiles (Crocodylus niloticus, LC) to change their diet.
Increased stress levels dueto these dietary and environmental changes leave the affected animals susceptible to pansteatitis (a condition where body fat becomes inflamed), leading to mass wildlife mortality events in South Africa’s Kruger National Park.
Lastly, dams reduce connectivity in freshwater ecosystems, preventing freshwater organisms from exchanging genetic material, migrating between upstream and downstream areas, and adapting to changing conditions.
For example, in West Africa, the damming of the Senegal River blocked the annual migration path for African river prawns (Macrobrachium vollenhoveni, LC), a major predator of snails that host schistosomiasis (bilharzia). Once the dam was completed, prawn populations collapsed, leading to a schistosomiasis epidemic in villages upstream from the dam.
Terrestrial ecosystems also suffer from dam construction. Of concern is the direct loss of riverine and palustrine ecosystems downstream from the dam due to reduced water flow. For example, the construction of Nigeria’s Kainji Dam in the Niger River caused the drying of large wetlands and floodplains downstream, in the process displacing nearly 400,000 people who depended on the river’s now compromised seasonal flood cycles.
Flooding of upland areas next to dammed rivers also displaces terrestrial wildlife and people. For example, the construction of Mali’s Manalati Dam flooded 430 km2of savannahs and 120 km2 of the forest, which fractured the migration routes of the region’s nomadic pastoralists, leading to overgrazing and soil erosion of the remaining grazing lands in addition to a 90% loss of fisheries downstream.
Wetlands
Throughout Africa, wetlands are being mined for valuable peat, or drained and/or filled in for development and agriculture. Through these activities, the region has already lost approximately 43% of its wetlands, with current rates of loss among the highest in the world.
This is a major concern because wetlands serve spawning grounds and nurseries for aquatic and amphibious wildlife and stop-over sites for migratory birds.
Wetlands also provide multiple important ecosystem services. For example, they prevent erosion and runoff by capturing large volumes of floodwater, which is then released slowly over time. This process also allows sediments and nutrients kicked up during flood events to settle out, creating fertile habitats for a wide diversity of animals and plants, as well as for agriculture.
Water that leaves after this settling period is cleaner than when it entered, having been filtered by the soil, plants, and microbes of wetlands. This water purification and filtration service is generally cheaper and much more efficient than man-made filtrations systems.
The loss of any wetlands, especially at such large scales, is thus a grave concern not only because of the countless animals and plants threatened with extinction, but also the people that depend on all the valuable ecosystem services they offer.
Addressing these declines, governments, conservation organizations, and local communities all over Africa have started initiatives to protect migratory birds and their habitats. One such initiative is happening in Kenya’s Tana River Delta, one of the most important stop-over sites along the Asian-East African Flyway.
Every year, Basra reed warblers (Acrocephalus griseldis, EN) return from their Middle Eastern breeding grounds to overwinter in the Delta, which covers 1,300 km2 and supports dozens of threatened species. The area, however, has been under serious threat from the development of sugarcane and biofuel crops since 2008.
These activities could reduce dry season water flow by up to one-third. Local people and conservationists strongly oppose these developments because of its threat to local communities’ ways of life and to wildlife populations. Their efforts gained international attention, and in 2012, Kenyan courts halted development until comprehensive management plans were developed that included environmental impact assessments and local stakeholder engagement.
Today, local people gain benefit from more sustainable industries, including eco-charcoal audited by the Forest Stewardship Council (FSC), and solar-powered energy to reduce the need for wood. Also, in West Africa, collaborative conservation initiatives are taking steps to protect the critical East Atlantic Flyway.
For example, under the guidance of BirdLife International, Guinea-Bissau residents are now monitoring several wetlands in the Bijagós Archipelago to track how well migratory waterbirds are doing at this critically important stop-over site. Also, in Senegal, where two important stop-over sites (Saloum Delta and Djoudj wetlands) are located, the local non-profit NGO Nature Communautés Développement initiated an extensive conservation education programme aimed at safeguarding the region’s birds.
Conserving migratory species that cover huge distances and rely on habitats in many areas is not easy. However, efforts like these in West Africa and Kenya (which combine the interests of local people and wildlife) provide excellent models for others to build from.
Mangrove swamps (sometimes called mangrove forests, though technically a wetland because their function and structure are primarily determined by hydrology, are one of Africa’s most threatened wetland ecosystems. Characterized by woody plants that can tolerate saltwater, mangrove swamps occupy brackish waters in tropical coastal areas, typically where there are muddy bottoms.
These areas are sparsely distributed; globally, mangrove swamps cover only 53,000 km2of land scattered across 118 countries. Protecting Africa’s mangrove swamps, comprising 21% of Earth’stotal, is important both biologically and economically.
In addition to holding many unique species, mangrove swamps also protect coastal cities and villages from cyclone/hurricane and tsunami damage and provide important breeding and feeding grounds for marine shellfish and fish.
One study estimated that mangrove swamps provide the estimated US $57,000 worth of ecosystem services per hectare. Yet, only 7% of Africa’s mangrove swamps are protected. With so little protection, it comes as no surprise that a large percentage of Africa’s mangrove swamps have been destroyed or damaged by agriculture, urban expansion, pollution, and commercial shellfish farming.
In WestAfrica, the situation is particularly dire. Wood extraction for commercial fish smoking is one of the biggest drivers of mangrove losses, even within protected areas. With so much destruction, it should come an as little surprise that about 40% of vertebrate species endemic to mangrove swamps are currently threatened with extinction.
Seasonal drylands
Africa is also rapidly losing its semi-arid savannahs, scrublands, and grasslands through conversion to agriculture and desertification—the systematic degradation of formerly complex and adaptive seasonal drylands into barren wastelands.
When human populations were low, nomadic pastoralism and shifting cultivation enabled people to utilize seasonal drylands in a sustainable way. Today, however, population growth, combined with restrictions placed on free movement by administrative borders and competition for land, forces people and animals living on drylands to be more sedentary.
While these areas may initially support some agriculture and livestock, unsustainable techniques, such as overgrazing and excessive tilling, lead to soil erosion and the depletion of soil nutrients and natural seed banks. With the cover vegetation gone, the unprotected topsoil is easily lost to wind and flooding, leaving behind the deeper, infertile, and compact subsoil layers with little capacity to hold water.
The result is something that closely resembles a man-made desert. However, rather than a functional ecosystem characterized by species adapted life in the desert, these wastelands have lost their original productivity and biological communities, only to be revived through expensive and/or time-consuming land reclamation methods.
We are currently witnessing the start of the sixth mass extinction of species on our planet. From here onwards, biodiversity losses are expected to increase rapidly: a recent UN report estimated that about one million species are already threatened with extinction.
While the reasons behind these losses vary by region, in Africa, a major driver is habitat loss. With the current push for development, the impacts of habitat loss are increasing dramatically, affecting species both inside and outside of protected areas.
Two Ethiopian birds, the Liben lark (Heteromirafra archeri, CR) and white-winged flufftail (Sarothrura ayresi, CR), exemplify many of the dilemmas associated with protecting biodiversity on unprotected lands where habitat loss is severe.
The Liben Plain is part of the Borana rangelands, managed by Borana pastoralists under their traditional rangeland management system which is generally compatible with conservation ideals. The Borana’s way of life was disrupted about 40 years ago due to pressure from a former Ethiopian government that wanted the Borana’s to adopt a more sedentary lifestyle.
For example, drilling of water wells in dry season grazing areas disrupted seasonal grazing systems, while fires that the Boranas used to maintain productive grazing lands and prevent shrub encroachment were prohibited. The Boranas also face pressure from changing land tenure systems.
The Liben Plain grasslands are located on communal lands upon which nobody can claim ownership. However, if someone wants to farm here, they just pay a tax that in effect assures ownership of the land. The Boranas were initially slow to adopt this farming lifestyle, but when outside settlers started taking advantage of the government’s farming incentives, the Boranas were pushed to do the same to prevent all their ancestral land from being turned over.
The subsequent loss of fire management (and associated shrub encroachment) and cropland expansion, together with increased human and livestock populations, have led to a major loss of the Liben Plains’ natural ecosystem.C Here, its main population is restricted to the open grasslands of the LibenPlain.
To prevent the extinction of the lark, the Ethiopian Wildlife and Natural History Society (EWNHS), BirdLife International, and other organizations collaborated with local authorities and community leaders in 2016 to establish enclosures for grassland regeneration.
These enclosures are ineffect communally-managed grassland reserves regulated under a subset of customary laws. These areas not only secure suitable habitats for the Liben lark, they also provide benefits to the Borana community like securing grazing lands for the dry season when the lark is not breeding.
This initiative shows early promise—over 350 ha of grassland reserves have already been established, and over 1,000 ha of shrubs have been cleared. But to truly secure the future of the Liben lark, more support is needed from the Ethiopian government, particularly in preventing further land conversion, supporting ecosystem restoration, and encouraging the Borana pastoralists’ traditional way of life.
Another species facing imminent extinction due to habitat loss is the white-winged flufftail. One of Africa’s most enigmatic birds, the flufftail is an intra-African migrant restricted to a few seasonal high-altitude wetlands in South Africa and Ethiopia.
Like the lark, the flufftail is a ground-nester that struggles to find suitable nesting sites relatively free from disturbance. The Berga floodplain, the flufftail’s Ethiopian stronghold, used to be covered by productive grasslands. This unspoiled landscape is now being replaced by settlements, crop farms, and eucalyptus plantations that generate quick profits.
This, together with overgrazing, has led to extensive soil erosion, which in turn has altered the structure and grass composition of the floodplain. Today, the floodplain is encroached by invasive weeds and other less desirable vegetation which, together with other forms of disturbance, have reduced the amount of suitable habitat available for the flufftails to such an extent that it is now considered Critically Endangered.
To prevent the extinction of the flufftail, the EWNHS along with the Middlepunt Trust and BirdLife South Africa has taken several steps to improve the outlook for the flufftail. Much of this work involved working with the people at Berga to improve their livelihoods and instill a sense of ownership of their local biodiversity.
A prominent outcome of this collaboration was a primary school named after the flufftail; results from the project also contributed to a species action plan. But without continued maintenance, the progress made by this short-term initiative will have limited long-term value.
The flufftail’s future thus continues to be dire, as unsustainable land-use practices continue to destroy the Berga floodplain. There is an urgent need for joint long-term efforts to reverse the fate of the species, including taking steps to establish protected areas, initiate carefully-planned ecosystem restoration efforts, and develop a new species management plan that will provide lasting benefits.
Erzsebet Frey (Eli Frey) is an ecologist and online entrepreneur with a Master of Science in Ecology from the University of Belgrade. Originally from Serbia, she has lived in Sri Lanka since 2017. Eli has worked internationally in countries like Oman, Brazil, Germany, and Sri Lanka. In 2018, she expanded into SEO and blogging, completing courses from UC Davis and Edinburgh. Eli has founded multiple websites focused on biology, ecology, environmental science, sustainable and simple living, and outdoor activities. She enjoys creating nature and simple living videos on YouTube and participates in speleology, diving, and hiking.