Impacts of the biological invasion by Ricinus communis L. on the native biota of the Atlantic Forest, Aracaju, Sergipe State, Brazil

The existence of environmental disturbances is an important facilitating factor to the establishment of biological invasions (BI). Biological invasions are considered the second biggest threat to the planet's biodiversity, behind only anthropic actions such as deforestation and habitat fragmentation. Thus, all environments are subjected to biological invasions, including Conservation Units (CU). The objective of the work was to evaluate the impacts of the exotic invasive Ricinus communis L. on the native biota of the Morro do Urubu Environmental Protection Area, Aracaju, Sergipe State, Brazil. Plots were allocated in places invaded by exotic invasive and in non-invaded places. Within the sample units, the number of individuals of each species present was counted. With these data, the statistics of the present study were performed. In the plots plotted on the non-invaded sites, 28 species were found. In the plots plotted on the invaded sites, only three species were sampled, among them the exotic invader studied, which showed to be the most abundant taxon in the area. In total, 75 individuals were counted in the invaded sites, of which 72 were from R. communis. In the non-invaded sites, 210 individuals. The average number of species was statistically higher in the plots where the exotic invader was removed, while from the second reading and remained until the eighth reading, the same happened for the average number of individuals. The results of this study showed the impacts caused by invasive exotic Ricinus communis on the composition, richness, diversity and resilience of an invaded Atlantic Forest area.(AU)

Impacts of the biological invasion by Ricinus communis L. on the native biota of the Atlantic Forest, Aracaju, Sergipe State, Brazil / Impacts of the biological invasion by Ricinus communis L. on the native biota of the Atlantic Forest, Aracaju, Sergipe State, Brazil

The existence of environmental disturbances is an important facilitating factor to the establishment of biological invasions (BI). Biological invasions are considered the second biggest threat to the planet's biodiversity, behind only anthropic actions such as deforestation and habitat fragmentation. Thus, all environments are subjected to biological invasions, including Conservation Units (CU). The objective of the work was to evaluate the impacts of the exotic invasive Ricinus communis L. on the native biota of the Morro do Urubu Environmental Protection Area, Aracaju, Sergipe State, Brazil. Plots were allocated in places invaded by exotic invasive and in non-invaded places. Within the sample units, the number of individuals of each species present was counted. With these data, the statistics of the present study were performed. In the plots plotted on the non-invaded sites, 28 species were found. In the plots plotted on the invaded sites, only three species were sampled, among them the exotic invader studied, which showed to be the most abundant taxon in the area. In total, 75 individuals were counted in the invaded sites, of which 72 were from R. communis. In the non-invaded sites, 210 individuals. The average number of species was statistically higher in the plots where the exotic invader was removed, while from the second reading and remained until the eighth reading, the

The existence of environmental disturbances is an important facilitating factor to the establishment of biological invasions (BI). Biological invasions are considered the second biggest threat to the planet's biodiversity, behind only anthropic actions such as deforestation and habitat fragmentation. Thus, all environments are subjected to biological invasions, including Conservation Units (CU). The objective of the work was to evaluate the impacts of the exotic invasive Ricinus communis L. on the native biota of the Morro do Urubu Environmental Protection Area, Aracaju, Sergipe State, Brazil. Plots were allocated in places invaded by exotic invasive and in non-invaded places. Within the sample units, the number of individuals of each species present was counted. With these data, the statistics of the present study were performed. In the plots plotted on the non-invaded sites, 28 species were found. In the plots plotted on the invaded sites, only three species were sampled, among them the exotic invader studied, which showed to be the most abundant taxon in the area. In total, 75 individuals were counted in the invaded sites, of which 72 were from R. communis. In the non-invaded sites, 210 individuals. The average number of species was statistically higher in the plots where the exotic invader was removed, while from the second reading and remained until the eighth reading, the

Impactos da invasão de Prosopis juliflora (sw.) DC. (Fabaceae) sobre o estrato arbustivo-arbóreo em áreas de Caatinga no Estado da Paraíba, Brasil / Impact of the invasion of Prosopis juliflora (Sw.) DC. (Fabaceae) in areas of Caatinga in the state of Paraíba, Brazil

Estima-se que as áreas invadidas por algaroba – Prosopis juliflora (Sw.) DC. (Fabaceae) no semi-árido nordestino já ultrapassam um milhão de hectares. O presente trabalho objetivou estudar os impactos da invasão de P. juliflora sobre a fitodiversidade e a estrutura do componente arbustivo-arbóreo, em remanescentes de caatinga no Estado da Paraíba. Usando-se o método de parcelas, foram amostrados quatro ambientes, nos quais os indivíduos de todas as espécies arbustivas e arbóreas foram inventariados e medidos, estimando-se os parâmetros estruturais das comunidades. Também foi calculada a diversidade, pelo índice de Shannon-Wiener (H’) e o índice de impacto ambiental de exóticas (IIAE). No total, foram amostradas 19 famílias, 35 gêneros e 39 espécies. A invasora foi responsável por mais de 70% de toda a estrutura dos ambientes inventariados. A baixa diversidade e o elevado valor de impacto ambiental obtidos para os ambientes invadidos revelaram, conjuntamente com os dados de estrutura das populações, os graves impactos que P. juliflora provoca nas comunidades invadidas. Evidencia-se com isso a formação de sistemas monodominados pela espécie invasora, o que revela a necessidade de controle efetivo de P. juliflora para se proteger o patrimônio genético autóctone.

It is estimated that invader populations of algaroba Prosopis juliflora (Sw.) DC. (Fabaceae) in the northeastern semi-arid, Brazil, cover more than one million ha. This study aimed to study the impacts of P. juliflora invasion on phytodiversity and on the structure of the shrub-tree component in caatinga fragments in Paraiba state. Four environments were sampled by plots in which all shrubtree individuals were surveyed and measured, estimating structural parameters of the communities. Diversity was estimated by the Shannon-Wiener index (H'), and the index of environmental impacts of exotic species (IIAE) was also calculated. A total of 19 families, 35 genera and 39 species were surveyed. Invader species accounted for more than 70% of the entire structure of the surveyed environments. The low diversity and the high environmental impact indexes obtained, as well as the structure of populations on the invaded communities, reveal that native communities are seriously jeopardized by P. juliflora. Interventions aiming at effective control of P. juliflora are recommended to protect the genetic heritage of native species.

Impactos da invasão de Prosopis juliflora (sw.) DC. (Fabaceae) sobre o estrato arbustivo-arbóreo em áreas de Caatinga no Estado da Paraíba, Brasil / Impact of the invasion of Prosopis juliflora (Sw.) DC. (Fabaceae) in areas of Caatinga in the state of Paraíba, Brazil

Estima-se que as áreas invadidas por algaroba Prosopis juliflora (Sw.) DC. (Fabaceae) no semi-árido nordestino já ultrapassam um milhão de hectares. O presente trabalho objetivou estudar os impactos da invasão de P. juliflora sobre a fitodiversidade e a estrutura do componente arbustivo-arbóreo, em remanescentes de caatinga no Estado da Paraíba. Usando-se o método de parcelas, foram amostrados quatro ambientes, nos quais os indivíduos de todas as espécies arbustivas e arbóreas foram inventariados e medidos, estimando-se os parâmetros estruturais das comunidades. Também foi calculada a diversidade, pelo índice de Shannon-Wiener (H) e o índice de impacto ambiental de exóticas (IIAE). No total, foram amostradas 19 famílias, 35 gêneros e 39 espécies. A invasora foi responsável por mais de 70% de toda a estrutura dos ambientes inventariados. A baixa diversidade e o elevado valor de impacto ambiental obtidos para os ambientes invadidos revelaram, conjuntamente com os dados de estrutura das populações, os graves impactos que P. juliflora provoca nas comunidades invadidas. Evidencia-se com isso a formação de sistemas monodominados pela espécie invasora, o que revela a necessidade de controle efetivo de P. juliflora para se proteger o patrimônio genético autóctone.(AU)

It is estimated that invader populations of algaroba Prosopis juliflora (Sw.) DC. (Fabaceae) in the northeastern semi-arid, Brazil, cover more than one million ha. This study aimed to study the impacts of P. juliflora invasion on phytodiversity and on the structure of the shrub-tree component in caatinga fragments in Paraiba state. Four environments were sampled by plots in which all shrubtree individuals were surveyed and measured, estimating structural parameters of the communities. Diversity was estimated by the Shannon-Wiener index (H'), and the index of environmental impacts of exotic species (IIAE) was also calculated. A total of 19 families, 35 genera and 39 species were surveyed. Invader species accounted for more than 70% of the entire structure of the surveyed environments. The low diversity and the high environmental impact indexes obtained, as well as the structure of populations on the invaded communities, reveal that native communities are seriously jeopardized by P. juliflora. Interventions aiming at effective control of P. juliflora are recommended to protect the genetic heritage of native species.(AU)