Influence of occupant microhabitat on the composition of encrusting communities on gastropod shells

The exploitation of microhabitats is widely considered to increase biodiversity in marine ecosystems. Although intertidal hermit crabs and gastropods may inhabit the same shell type and shore level, their microhabitat may differ depending on the state of the tide. On the south coast of Wales the hermit crab Pagurus bernhardus mainly inhabits the shells of Nucella lapillus (84%). Hermit crab shells had a significantly different encrusting community compared with live N. lapillus shells. At low tide the live gastropods were found on exposed rock surfaces whereas hermit crabs were restricted to tidal pools. Communities encrusting live gastropod shells were characterised by lower species richness and abundance compared with shells inhabited by hermit crabs (12 species found in total). A greater abundance and richness of epibionts was recorded from both shell types during the summer compared with winter. Differences in community composition between shell occupant types were attributed to microhabitats used by gastropods and hermit crabs and the associated desiccation pressures, rather than competitive interactions or shell characteristics. This contradicts earlier studies of subtidal shells where biological processes were considered more important than physical factors in controlling species abundance and richness patterns. The use of rockpool microhabitats by hermit crabs increases the biodiversity of rocky shores, as some species commonly found on hermit-crab-inhabited shells were rare in other local habitats.

Communities of practice in construction case study organisations: questions and insights

Purpose – At the heart of knowledge management (KM) are the people – an organisation's important knowledge asset. Although this is widely acknowledged, businesses seldom understand this axiom in terms of the communities through which individuals develop and share the capacity to create and use knowledge. It is the collective learning that takes place within the social systems, i.e. communities of practice (CoP) that are of particular significance to an organisation from a KM perspective. This paper aims to review, critique, and raise some pertinent questions on the role of CoPs; and with the help of case studies shed light on the “goings-on” in construction practices. Design/methodology/approach – After critically reviewing the literature on CoPs and querying some underlying assertions, this research investigates how these issues are addressed in practice. A case study approach is adopted. Three organisations operating in the construction sector are interviewed for the purpose of this paper. Findings – Case study findings highlight the potential challenges and benefits of CoPs to a construction organisation, the role they play in generating and delivering value to the organisation and their contribution towards the collective organisational intelligence. From the findings, it is clear that the question is not whether communities exist within organisations, but how they deliver value to the organisation. From an organisational perspective, the key challenge is to provide an environment that is conducive to developing and nurturing such communities as opposed to merely creating them. Practical implications – Challenges and benefits demonstrated through the case studies should be taken in context. The findings are not intended to be prescriptive in nature, but are intentionally descriptive to provide contextual data that allow readers to draw their own inferences in the context of their organisations. They should be applied taking into account an organisation's unique characteristics and differentiators, the dynamics of the environment in which it operates and the culture it harbours within. Originality/value – Investigating the role of CoPs in the context of case study construction organisations forms the prime focus of this paper.

Building communities via a learning landscape

The Learning Landscape project described here is known as RedGloo and has several objectives; among others it aims to help students to make friends, contacts and join communities based on interests and competencies. RedGloo provides a space where students can support each other with personal, academic and career development, sharing insights gained from extracurricular activities as well as their degree programmes. It has shown tendencies of becoming a learning community with several communities of practice.

Child labour in African Artisanal Mining Communities: experiences from Northern Ghana

The issue of child labour in the artisanal and small-scale mining (ASM) economy is attracting significant attention worldwide. This article critically examines this ‘problem’ in the context of sub-Saharan Africa, where a lack of formal sector employment opportunities and/or the need to provide financial support to their impoverished families has led tens of thousands of children to take up work in this industry. The article begins by engaging with the main debates on child labour in an attempt to explain why young boys and girls elect to pursue arduous work in ASM camps across the region. The remainder of the article uses the Ghana experience to further articulate the challenges associated with eradicating child labour at ASM camps, drawing upon recent fieldwork undertaken in Talensi-Nabdam District, Upper East Region. Overall, the issue of child labour in African ASM communities has been diagnosed far too superficially, and until donor agencies and host governments fully come to grips with the underlying causes of the poverty responsible for its existence, it will continue to burgeon.