Chromolaena odorata invasion in Nigeria: A case for coordinated biological control

Abstract

The presence of the North American Marmorkrebs (Procambarus fallax f. virginalis) in European inland waters is entirely driven by ongoing propagule pressure from the ornamental trade. Since 2003 at least 25 independent introduction events have been confirmed, of which some have eventually resulted in established populations. This study links a maximum-entropy model that forecasts the probability of Marmorkrebs introduction based on socioeconomic predictors to an updated species distribution model based on environmental predictors in order to explore the risk of further Marmorkrebs establishment in Europe. In line with related research, the probability of Marmorkrebs release was largely affected by gross domestic product and human population density, i.e. predictors very likely related to the density of Marmorkrebs owners, whereas environmental suitability was mostly influenced by minimum temperature and the availability of lentic habitats, which was indirectly assessed by terrain slope. While considerable parts of Europe were predicted as potentially suitable for establishment, high probabilities of introduction were forecasted in much smaller geographic areas. The consensus map of the model predictions suggests that introduction and subsequent establishment of Marmorkrebs is likely to occur in much of Germany, the Benelux countries, England, Italy, and areas of high human population density throughout France and Spain, as well as parts of southernmost Scandinavia and Southeastern Europe. Monitoring trades of Marmorkrebs in these high-risk regions is recommended and implications for proactive measures are discussed, including the need for consistent trade regulations at the EU level.

Impact of mining on the floristic association of gold mined sites in Southwest Nigeria

“…It is an aggressive competitor with allelopathy effects. Its sparse status on the control site compared to the two mined sites suggests low level of disturbance [44]. Also widespread in the tropics include Melanthera scandens, Sida pilosa and Paullinia pinnata which is usually in regrowth vegetation, and Commelina erecta; particularly in the forest woodland areas.…”

The nocturnal larvae of a specialist folivore perform better on Chromolaena odorata leaves from a shaded environment

“…Chromolaena odorata is a scrambling perennial shrub native to the Americas from southern USA to northern Argentina (Gautier, ). In its invasive range, C. odorata grows in a wide range of vegetation types such as forest margins, grasslands, roadsides, agricultural lands and disturbed forests posing a significant threat to agriculture, biodiversity and livelihoods (Zachariades et al., ; Uyi & Igbinosa, ; Uyi et al., ). The weed is intolerant of deep shade, but performs well under partial shade and full‐sun (high light) conditions (Zachariades et al., ; Zhang & Wen, ).…”

Chromolaena odorata (L.) R.M. King & H. Rob. (Asteraceae) in sub-Saharan Africa: A synthesis and review of its medicinal potential

“…While C. odorata has been declared a 'Category 1' weed under the Conservation of Agricultural Resources Act (CARA) and the National Environmental Management Biodiversity Act (NEMBA) on Alien and Invasive Species List in South Africa because of its invasiveness in the north-eastern parts of the country (Goodall and Erasmus, 1996;Nel et al, 2004;Zachariades et al, 2011), the situation in West Africa remains contentious despite numerous research reports and the perceived usefulness of the plant in the latter region (Uyi et al, 2014). In view of its coverage of large areas, and its invasive propensity, the use of chemical, mechanical and other conventional methods of controlling the weed have proven not to be sustainable (Timbilla et al, 2003;Zachariades et al, 2009;Uyi and Igbinosa, 2013).…”

“…The invasive success of C. odorata is thought to depend upon a combination of several factors such as; (i) high reproductive capacity; (ii) high growth and net assimilation rates; (iii) its capacity to suppress native vegetation through competition for light and allelopathic properties; and (iv) its ability to grow in many soil types and in many climatic zones (Zachariades et al, 2009;Uyi et al, 2014).…”

“…The status of C. odorata as an agricultural and environmental weed has been a subject of burgeoning concern in the past four decades in west and southern sub-Saharan Africa, probably because of its invasiveness in agro-ecosystems and conservation areas (Ivens, 1974, Lucas 1989Goodall and Erasmus, 1996;Timbilla et al, 2003;Uyi et al, 2014). The invasive success of C. odorata is thought to depend upon a combination of several factors such as; (i) high reproductive capacity; (ii) high growth and net assimilation rates; (iii) its capacity to suppress native vegetation through competition for light and allelopathic properties; and (iv) its ability to grow in many soil types and in many climatic zones (Zachariades et al, 2009;Uyi et al, 2014).…”