Local ecological knowledge concerning the invasion of Amerindian lands in the northern Brazilian Amazon by Acacia mangium (Willd.)

Abstract

IntroductionInvasive plants can impact biodiversity as well as the lives of native human populations. Natural ecosystems represent sources of natural resources essential for the subsistence and socio-cultural continuity of these social groups. Approximately 30,000 ha of Acacia mangium were planted for commercial purposes in savanna areas surrounding indigenous lands in Roraima State, Brazil, at the end of the 1990s. We examined the local ecological knowledge of indigenous Wapichana and Macuxi Amerindians, members of the Arawak and Carib linguistic families, respectively, concerning A. mangium Willdenow (Fabaceae) in a savanna ecosystem (“Lavrado”) to attempt to understand its propagation beyond the limits of the commercial plantations and contribute to mitigating its impacts on socio-ecological systems.MethodsThe present study was undertaken in the Moskow, São Domingos, and Malacacheta communities in the Moskow and Malacacheta Indigenous Lands (ILs) in the Serra da Lua region of Roraima State, in the northern Brazilian Amazon region. Interviews were conducted with a total of 94 indigenous individuals of both sexes, with ages between 18 and 76, and low levels of formal schooling, with an average time of permanence in the area of 21 years; some still spoke only their native languages. The interviews focused on their ecological knowledge of the invasive, non-native A. mangium and their uses of it.ResultsThe informants affirmed that A. mangium negatively impacted the local fauna and flora, making their subsistence more difficult and altering their daily routines. Among the problems cited were alterations of water quality (71.3%), negative impacts on crops (60.6%), negative impacts on the equilibrium of the local fauna (52.1%), increased farm labor requirements (41.5%), and restriction of access to indigenous lands (23.4%). There were no significant differences between the opinions of men and women, nor between community leaders and nonleaders. Most of the interviewees (89%) felt that A. mangium had no positive importance for the local economy and saw no future prospects of beneficial use.ConclusionsThe Wapichana and Macuxi informants felt that the invasion by A. mangium had caused negative effects on the natural environment and on community subsistence in the indigenous lands due to its rapid and unwanted propagation. The similarity between the opinions of men and women and between community leaders and nonleaders demonstrates the existence of knowledge that is well distributed among these communities and transmitted within their communities through social–cultural interactions.

Invasive alien plant species: Their impact on environment, ecosystem services and human health

“…Several IAPS, introduced for human welfare are known to create environmental and economic havoc (Souza et al, 2018). Therefore, people's perception about IAPS as well as their local ecological knowledge can be an effective approach to categorize the IAPS impacts.…”

“…Therefore, people's perception about IAPS as well as their local ecological knowledge can be an effective approach to categorize the IAPS impacts. In this context, Acacia mangium, an IAPS in northern Brazilian Amazon, is noted for its harmful effects to economy, environment and indigenous people through alteration of the water quality (Souza et al, 2018).…”

Acacia mangium Willd: benefits and threats associated with its increasing use around the world

“…In some countries, A. mangium is considered an invasive tree species (Richardson and Rejmánek 2011;Low 2012;Rejmánek and Richardson 2013;Attias et al 2013;Aguiar et al 2014;Sampaio and Schmidt 2013;Richardson et al 2015;Witt 2017;Souza et al 2018). We could find no statistics on the extent of invasions or the area invaded in different regions.…”

“…Introduction of A. mangium to agricultural, agroforestry or large open areas is, however, increasingly being shown to trigger major biological invasions. The number of publications documenting the invasive spread of A. mangium from planting sites is increasing rapidly; the species is currently recorded as an invasive species in Asia, Indonesia, southern Africa and South America (Richardson and Rejmánek 2011;Ismael and Metali 2014;Aguiar et al 2014;Meira-Neto et al 2018;Souza et al 2018). Such invasions are reducing the overall benefit from using the species and is creating conflicts of interest between (agro) foresters on the one hand and conservationists and natural resource managers on the other.…”

“…This is the fundamental mediator of thresholds that facilitate major biotic and abiotic impacts (Gaertner et al 2014). Widespread invasions of Australian acacias in many parts of the world have led to increasing conflicts of interest regarding the benefits and negative impacts of the species (Kull and Rangan 2008;Richardson and Rejmánek 2011;Wilson et al 2011;Tassin et al 2012;Ismael and Metali 2014;Aguiar et al 2014;Kull et al 2018;Souza et al 2018).…”