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The savannas of Guyana: cultural and social importance, biodiversity and conservation challenges

In January 2020, a new scientific article published in Tropical Conservation Science summarizes current knowledge on the cultural and social importance, but also on the ecology of the Guyana savannas. In order to enhance this article, we offer you a summary of this publication in French.

Tropical savannahs

African savannah landscape

Tropical savannahs cover 15 to 24.6 million km² in South America, Asia and Africa. Local populations live and subsist thanks to these ecosystems but an unreasonable use has led to the degradation of these savannas and led to a loss of their biodiversity as well as of the services from which humans benefit.

The savannas of French Guiana

Guyana savannahs landscape © Dewinter / BIOTOPE

97% of Guyana is covered by one of the best preserved tropical forests on the planet, the subject of worldwide scientific interest. Guyanese savannahs, on the other hand, cover only 0.3% of the territory (or 251 km²) and are located on its coastal plains, where 95% of the population and infrastructure are also. Despite this, the Guyana savannas are the subject of very little scientific research and are not mentioned in most of the articles written on tropical Amazonian savannas. However, this research is necessary in order to better characterize their geographic distribution, their area, their threats and the historical and current uses of these ecosystems.

Cultural significance and human use

Men have used savannas for millennia, first during the Pre-Columbian period, from the 7th to the 16th century when agriculture was applied by the Amerindians who populated the coast and transformed the savannas into raised fields. From the 18th century, small Creole dwellings appeared in these open landscapes where the inhabitants practiced animal husbandry until the 1950s. The Creole population then lived in scattered houses, built on the edge of savannas where several activities and spaces complementary make these homes almost self-sufficient.
In the 1970s, the French government implemented a development plan called the Green Plan, helping farmers to settle in areas with savannas and initiating a change in agricultural practices, particularly on livestock now placed in fenced plots and private on more intensive pastures. This new system of land use is opposed to the communal use of land carried out in the past and impacts the lifestyles of the Creole and Amerindian communities which for some still exploit these ecosystems through fishing, gathering and ‘Agriculture.

Ecological importance and biodiversity
Bearded Tachuri © Sylvain Uriot (savanes.fr)
Like the other Amazonian savannas, those of Guyana are composed of a complex of several natural habitats. The raised fields created by humans are surely one of the reasons for these variations, thus improving local biodiversity. Indeed, the Guyana savannas within raised fields have the highest densities of invertebrates in the soils recorded in tropical savannas. Although Guyana has more than 700 species of birds, 21 species are observed specifically in savannahs, 81% of which are threatened on a regional scale. In addition, two mammalian species are dependent on savannahs, such as a new species of Opossum Mouse Cryptonanus sp.. Finally, 10 species of reptiles and two species of amphibians are also associated with these ecosystems. Finally, 16% of the Guyanese flora is present in these Guyanese savannas.

Influencing factors

Fires

Savannah fires – Trou poisson © Anna STIER

In Guyana, it has been shown that 62% of the savannas between Cayenne and Organabo burned at least once between 2006 and 2010. These fires take place mainly during the long dry season from July to December, and can play an important role in the maintenance and evolution of certain habitats of these ecosystems. Despite the ban on burning, intentional illegal fires are still occurring, creating conflicts between different actors in the territory.

Agricultural practices

Modern agriculture is considered to be one of the main threats to savannahs around the world. In Guyana, activities like plowing or building fish ponds not only erase raised fields but also alter drainage patterns. In Latin America, the increase in monoculture eucalyptus and pine projects or rice or soybean production within these savannas has led to the transformation of these habitats and led to the loss of savannas. In Guyana, such intensive farming projects have seen the light of day in the past but have all failed or been abandoned. Currently, buffaloes and cows are raised extensively but on limited plots.

Invasive alien species

Acacia mangium on the Guyana savannah © Anna STIER

Located in the most anthropized area of ​​Guyana, savannas are particularly exposed to invasive alien species introduced voluntarily or not by humans. In addition, these savannas are distributed in the form of small patches separated by different ecosystems such as mangroves, marshes and forests or by human infrastructure, which makes them sensitive to invasive exotic species.
Among the 490 invasive alien plants registered in Guyana, Acacia mangium and Niaouli are the most worrying because of their distribution and their ability to modify environmental conditions. With very rapid growth and fire resistance, these plants are predisposed to invade savannas. Introduced from Australia in the 1970s to revegetate mining sites, Acacia mangium has now invaded Guyana to the point where it is now impossible to imagine complete eradication of the species. Niaouli was favored in the 1970s in favor of the development of the paper industry. Unfortunately, little research has been done on the impact of the species on the territory.

Infrastructure development and urbanization

Anthropic pressures on the savannas of Guyana © Anna STIER

In a context of demographic growth and economic liberalization, public land reforms and political, land and economic changes, the savannahs were nibbled by the construction of projects such as the construction and expansion of the Guyanese Space Center, by the installation of solar panels, wind turbines or the establishment of roads requiring the construction of embankments in these seasonally flooded areas. The recent increase in residential construction in Guyana has also contributed to the erosion of wetlands and savannas.

Conservation status of the Guyana Amazonian savannas

Father’s Savannah in Guyana © Florent BIGNON / LPO

Despite the threats to these ecosystems, less than 2.2% of their area is under regulatory protection, while their area was reduced by 7% between 2001 and 2015. In addition, 75% of savannahs are located in Natural Area of special Ecological, Faunistic or Floristic Interest (ZNIEFF) which demonstrates the importance of these ecosystems. Despite everything, in 2016, the Regional Planning Scheme validated by a decree specifies the prohibition of certain activities such as the creation of quarries, agricultural or industrial activities on these surfaces classified ZNIEFF. Finally, 42.8% of the savannas of Guyana are present on the grounds of the Guiana Space Center.

Recommendations

Despite the threats hanging over the Guyana savannas, these remain under-studied and under-protected. There is an urgent need to improve knowledge through research on ecological functioning, socio-environmental interactions and responses to environmental change.

The uniqueness of each savannah must be taken into account and conservation measures must be adapted to each of them. Savannas are unique socio-ecosystems whose maintenance and change factors are different from one savannah to another because of the unique history of each patch: conservation measures must be created and adapted to each patch of savannah and will have to take into account historical, cultural and social aspects in addition to environmental and ecological processes.

The Amazonian savannahs are different from the tropical savannahs, which must be recognized and valued so that this can unlock suitable conservation policies. Finally, it is also a question of responsibilities, that of the national and regional authorities in the conservation of these socio-ecosystems but also that of scientists and environmental professionals who must communicate their knowledge and information on the savannahs of Guyana.

Fore more information :

Original scientific publication