Predicting current and future distribution of Hovenia dulcis Thunb. (Rhamnaceae) worldwide

Biological invasions are increasingly recognized as one of the major threats to biodiversity. The Japanese raisin tree (Hovenia dulcis) is native to East Asia, however, in southeastern South America this species has become one of the most pervasive invaders. Hovenia dulcis has many biological characteristics that favor the process of invasion and few studies have indicated changes in the structure and composition of native plant communities where this species has become invader. Given the invasiveness shown in southeastern South America, our main goal was to identify the potentially suitable habitats for this invasive species at a global scale. In this sense, we modeled the potential distribution of H. dulcis along the terrestrial areas worldwide using an ensemble forecasting approach. Additionally, the percentage of overlapping biodiversity hotspot areas with the currently suitable areas for this species was calculated. Our results revealed that the current potential H. dulcis range is equivalent to 7.88% (12,719,365 km2) of the terrestrial area worldwide. For the future scenarios of climate change, the potential distribution area tends to have a small reduction. However, significant suitable areas were identified for H. dulcis range in the northern limits of the boreal distribution. Currently, around 17% of biodiversity hotspot areas overlap with the suitable areas for H. dulcis occurrence. In summary, given that the prevention is well-recognized as a more effective management action against invasive alien species, it is essential to implement policies to prevent H. dulcis introduction in suitable areas worldwide, as well as local population control, especially in biodiversity hotspots

Red swamp crayfish: biology, ecology and invasion - an overview

Alien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modifications in invaded environments causing irreparable ecological and economic damages. Its impressive ability to successfully colonize a wide range of environments is a consequence of its behavioural and biological characteristics that can adapt to features of the invaded location, conferring to this species a notable ecological plasticity. This review summarizes the available information regarding P. clarkii’s biology and invasive dynamics around the world in order to contribute to the understanding of the threats posed by its establishment, as well as to support management and impact mitigation efforts

Distribution, introduction pathway, and invasion risk analysis of the North American crayfish Procambarus clarkii (Decapoda: Cambaridae) in southeast Brazil

This study reports new records of Procambarus clarkii Girard, 1852 in Southeastern Brazil and investigates its possible pathways of introduction. The Brazilian crayfish pet trade was surveyed with regard to species’ availability and price, reporting its persistence, even though illegal. An invasion risk analysis was performed by applying a protocol developed specifically to invasive freshwater invertebrates (FI-ISK). Procambarus clarkii has confirmed occurrences from urban and non-urban areas in the state of São Paulo, including the Jaraguá State Park, an Atlantic Forest conservation area. The pet trade is an important introduction vector but some subsequent translocation can also be due to the release of live bait by anglers. Besides passive dispersal, these newly discovered populations, especially those located in non-urban areas, are likely to naturally disperse further through active spread and river drift of juveniles. Although confirmed colonized areas are all located in the state of São Paulo, the invasive risk analysis showed that P. clarkii is a potential highly invasive species for Brazil. These introductions have unknown consequences; however, many impacts are associated with this species establishment around the world, underlining the urgency to understand the invasion process in Brazil and develop efficient management techniques

Growth curve of Balloniscus glaber Araujo & Zardo (Crustacea, Isopoda, Oniscidea) from Parque Estadual de Itapuã, Rio Grande do Sul, Brazil Curva de crescimento de Balloniscus glaber Araujo & Zardo (Crustacea, Isopoda, Oniscidea) no Parque Estadual de Itapuã, Rio Grande do Sul, Brasil

Based on field data, this study presents the growth curve of Balloniscus glaber Araujo & Zardo, 1995, a terrestrial isopod species found in Parque Estadual de Itapuã (PEI), Rio Grande do Sul, Brazil. Specimens were monthly sampled, from May 2004 to April 2005, at PEI. Captured individuals were sexed, their cephalothorax width was measured, and the growth curve was described according to von Bertalanffy's model. Male and female growth curves are described by the equations: Wt = 2.256[1-e-0.00394(t+91.128)] and Wt = 2.588[1-e-0.00301(t+101)], respectively. Curves show differential growth between males and females, with females reaching higher W<FONT FACE=Symbol>&yen;</FONT>, and a slower growth rate than males. Based on theses curves, life span was estimated.<br>Esse estudo, baseado em dados de campo, esse estudo apresenta a curva de crescimento de Balloniscus glaber Araujo & Zardo, 1995, um isópodo terrestre encontrado no Parque Estadual de Itapuã (PEI), Rio Grande do Sul. Os espécimes foram coletados mensalmente, de maio de 2004 a abril de 2005, no PEI. Os indivíduos capturados foram sexados e tiveram o cefalotórax mensurado e a curva de crescimento descrita a partir do modelo de von Bertalanffy. As curvas de crescimento para machos e para fêmeas são descritas pelas equações: Lt = 2,256[1-e-0,00394(t+91,128)] e Lt = 2,588[1-e-0,00301(t+101)], respectivamente. As curvas apresentam crescimento diferencial entre machos e fêmeas, com fêmeas atingindo maior L' mas com uma taxa de crescimento menor do que os machos. Com base na curva foi estimada a longevidade dos animais