The Physicochemical Characteristics of Ibiekuma River Ekpoma, Nigeria

The Ibiekuma River is an important source of livelihood to its catchment. It contributes enormously to research success and living standard of students and staffs of the Ambrose Alli University Ekpoma, Nigeria. The aim of the study was to determine the impact of anthropogenic activities on the physicochemical properties of Ibiekuma River. Twenty seven water samples were collected at four stations during the study period and analyzed accordingly. The results obtained shows that the physicochemical parameters of the river were in conformity with the World Health Organization (WHO), National Agency for Food, Drug Administration and Control (NAFDAC) and Nigerian Industrial Standard (NIS) safe limits, except for pH values which ranged from 4.69 to 4.81. The heavy metal concentrations were found to be within the limit of the guidelines prescribed by WHO and NAFDAC. Also, there was no significant difference (P > 0.05) in the concentrations of the physicochemical parameters across the four stations sampled along the Ibiekuma River. Water obtained from Ibiekuma River will be fit for domestic use, only if purified

Eight decades of invasion by Chromolaena odorata (Asteraceae) and its biological control in West Africa: the story so far

Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae) is a perennial weedy shrub of neotropical origin and a serious biotic threat in its invasive range. The Asian-West Africa (AWA) biotype of C. odorata present in West Africa is both morphologically and genetically different from the southern African (SA) biotype. The AWA biotype was first introduced into Nigeria in the late 1930s and rapidly spread across West Africa. Currently, 12 of the 16 countries in West Africa have been invaded, with significant negative effects on indigenous flora and fauna. However, locals in West Africa have found several uses for the weed. As chemical, physical and other conventional methods were unsustainable, costly and largely ineffective, three biological control agents, Apion brunneonigrum (Coleoptera: Brentidae), Pareuchaetes pseudoinsulata (Lepidoptera: Erebidae) and Cecidochares connexa (Diptera: Tephritidae), have been released in West Africa between the 1970s and the early 2000s. However, only C. connexa and P. pseudoinsulata established, contributing to the control of the weed, in six and four countries in West Africa respectively. Limited research funding, the absence of post-release evaluations of the established agents, and the ?conflict of interest? status of C. odorata (i.e. being beneficial for local use but damaging to ecosystem services and agriculture), are serious factors deterring the overall biological control effort. Here, using historical records and field surveys, we examine the invasion history, spread, impacts, and management of C. odorata in West Africa and make recommendations for the sustainable management of C. odorata in the region

Plant size, latitude, and phylogeny explain within-population variability in herbivory

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth