Colonisation by epibionts and meiofauna of real and mimic pneumatophores in a cool temperate mangrove habitat

The size and pace of change in meiofaunal assemblages suggest that meiofauna make excellent subjects for testing theories about how ecological communities change. A field experiment was performed in which the  abundance and composition of epibionts and meiofauna on natural,  transplanted and mimic pneumatophores were monitored over a 47 wk period. Meiofaunal density increased with growth of algal epibionts, both reaching maximum values after 24 wk, at the end of winter. At this time the assemblages from the 3 substrata were similar, although the combined abundances of meiofauna on transplants and mimics were only 28% of the average on natural pneumatophores. Meiofaunal abundance on all substrata decreased rapidly during spring as algal cover declined due to desiccation. Twenty-three species of nematode were recorded from mimics compared with 8 and 7 from transplants and pneumatophores, respectively. A temporal sequence of feeding groups occurred in the order of epigrowth feeders, deposit feeders, and omnivore/predators, with the latter 2 adding to rather than replacing earlier trophic groups. Scavengers were found only on natural pneumatophores. The turnover rates of nematode species between all census times were similar, peaking at 63%, but there was no trend in the turnover rates with time. We conclude that mimics are more suitable than transplanted pneumatophores for colonisation studies because of their greater persistence and more easily standardised surface area. Moreover, the composition of colonising assemblages on them closely resembled assemblages on natural pneumatophores at the time of peak meiofaunal abundance.

The classification of lands managed for conservation : existing and proposed frameworks, with particular reference to Australia

Comprehensive classification systems to accurately account for lands managed for biodiversity conservation, are an essential component of conservation planning and policy. The current international classification systems for lands managed for nature conservation are reviewed, with a particular emphasis on Australia. The need for a broader, all-encompassing, categorisation of lands managed for conservation is presented and a proposed broader categorisation system is developed—the Conservation Lands Classification. This classification system has the advantage of incorporating data on both tenure and protection mechanisms and has been applied in this paper using conservation lands in three Australian jurisdictions as examples. It is envisaged that this method of classification has the potential to significantly improve the ability to measure current and future trends in nature conservation across all land types at a variety of scales and hence is put forward in order to stimulate discussion on this important topic.

The effect of grazing gastropods on meiofaunal colonisation of pneumatophores in a temperate mangrove

A field experiment was run to assess how grazing affects meiofaunal colonisation of mimic pneumatophores in a temperate mangrove. The effects of two manipulated factors were tested: mimics (made from wooden dowel rods) were either implanted into the sediment, or suspended just above the substratum; and in addition were either fitted with an aluminium 'snail barrier' or left without. The abundance of meiofauna was estimated on the 4 treatments after 2, 4, 8 and 16 weeks in situ in the intertidal region. After 16 weeks the meiofaunal assemblage was dominated by copepods, and the effect of suspension was highly significant on abundance of the epibiotic assemblage. Mimics suspended above the sediment, out of reach of snails, were fouled with a green algal layer whereas implanted units were not. In contrast, 'snail barriers' were found to be relatively ineffective in preventing access by the dominant herbivorous gastropod Bembicium melanostomum. Meiofaunal assemblages were more abundant on suspended units, but there was greater taxonomic richness at levels of phylum and class on implanted units than on   suspended units. The colonising meiofaunal assemblage was less abundant on implanted mimics than in previous experiments at this study site, and this was attributed to the present experiment being carried out during the dry summer period, when meiofauna on pneumatophores is in decline.

The culture-based fisheries in small, farmer-managed reservoirs in two provinces of northern Vietnam: an evaluation based on three production cycles

In this paper the results of a study conducted on the culture-based fisheries in small (ranging from 2 to 160 ha), farmer-managed reservoirs in YenBai and ThaiNguyen Provinces in the northern highland region of Vietnam, for the production cycles of 1997/98, 98/99 and 99/00 are presented. The small reservoirs are leased to small farmers by the provincial authorities for fishery activities, and all lessees adopt culture-based fisheries when fingerlings of grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), common carp (Cyprinus carpio) and mrigal (Cirrihinus mrigala) are stocked between March and mid-April each year and harvested, using large seine nets, after approximately 11-12 months. The mean yields from reservoirs in YenBai and ThaiNguyen Provinces in 97/98, 98/99 and 99/00 production cycles were 251, 332 and 253, and 331, 372 and 210 kg ha⁻¹ respectively. There were major differences in the fish productivity in the reservoirs in the two Provinces, and in a reservoir between culture cycles. The stocking strategies appeared to be rather ad hoc, being determined by the availability of seed stock and the financial status of the lessees. Accordingly, there was no apparent consistent trend in the improvement of yields from the culture-based fishery practice throughout the growth cycles. The fish yields in reservoirs in each Province were significantly related to reservoir area (exponentially) and to mean weight of stocked fish and conductivity (logarithmically). Of the stocked fish, the highest returns were obtained with mrigal and bighead carp, which collectively contributed > 50% to the harvest. The return from common carp was the lowest. The mean growth rate of grass carp (2.7 g day⁻¹), followed by bighead carp (2.0 g day⁻¹) was the highest in reservoirs in YenBai Province, bighead carp (4.0 g day⁻¹) followed by grass carp (3.2 g day⁻¹) was the highest in ThaiNguyen Province. The seed stocked on average accounted for 65% and 48% of the total operating costs in YenBai and ThaiNguyen Provinces, and the mean cost:benefit ratio of the culture-based fishery in the two Provinces was 0.35 and 0.37 respectively. The culture-based fishery on average contributed about 28% to the gross income of a farmer lessee.

Drifting or walking? colonisation routes used by different instars and species of lotic, macroinvertebrate filter feeders

Many views of stream invertebrate populations centre on drift as the major route of larval dispersal, but few studies have presented unambiguous information about the role of drift. We present the results from an experiment designed to determine whether the major route of colonisation of substrata by hydropsychid larvae (commonly found in the drift) is by drifting directly onto substrata or by walking along the stream bottom. The experimental design contained four treatments: substrata open to drifters and walkers; fenced substrata open to drifters only; and two treatments open to drifters and walkers that provided forms of fence controls. Fifteen replicates of each treatment were set out at random locations within a riffle at each of three sites, with each site on a different river (the Little River, the Steavenson River and the Acheron River) in the Acheron River catchment. The experiment was run twice, once during autumn (April 1999) and once during early summer (January 2000). Both experiments were colonised by three species of hydropsychids, Asmicridea sp. AV1, and Smicrophylax sp. AV1 and AV2. We found that 2nd/3rd instars of Asmicridea sp. AV1 walked as well as drifted, whereas all others primarily drifted. No relation between numbers of recruits and water speed was found when substrata were open only to drifters, whereas substrata open also to walkers gained more recruits in faster flows. Additionally, larvae more frequently abandoned nets in slow than fast flows, indicating that drifting into unfavourable flow environments may result in mortality or redispersal of larvae. These findings demonstrate that, although drift is important, it is not necessarily the only method used by hydropsychids to colonise substrata. Larvae may have more capacity to choose substrata in fast flows when they colonise substrata by walking. Spot measures of hydropsychid distribution cannot distinguish between these explanations. The finding that walkers can sometimes comprise significant numbers of recruits raises the prospect that hydropsychids can be sourced locally and have not inevitably drifted in from upstream locations.

The link between self-managed work teams and learning organisations using performance indicators

Both the learning organization literature and the self-managed work team literature have alluded to the potential links between teamwork and learning. However, as yet the link between these two concepts remains undeveloped. This study uses a survey of a random sample of 200 Australian organizations to empirically examine the relationships between self-managed work teams and the learning organization using performance indicators as a medium. It was found that the learning organization concept displays a moderate to strong link with three measures of performance used in this study: knowledge performance, financial performance and customer satisfaction. Although the self-managed work team concept did not display any significant relationship with performance, the qualitative component of the survey did emphasize that there is a common belief that self-managed teams can increase performance in the right setting. While an insignificant relationship between self-managed teams and the learning organization was also found, this study suggests some methodological concerns for future research into the relationship between self-managed teams and the learning organization.

Web-based self-service systems for managed IT support: service provider perspectives of stakeholder-based issues

This chapter explores the provision of after-sales information technology (IT) support services using Web-based self-service systems (WSSs) in a business-to-business (B2B) context. A recent study conducted at six large multi-national IT support organisations revealed a number of critical success factors (CSFs) and stakeholder-based issues. To better identify and understand these important enablers and barriers, we explain how WSSs should be considered within a complex network of service providers, business partners and customer firms. The CSFs and stakeholder-based issues are discussed. The chapter highlights that for more successful service provision using WSSs, IT service providers should collaborate more effectively with enterprise customers and business partners and should better integrate their WSSs.

The cost of community-managed viral respiratory illnesses in a cohort of healthy preschool-aged children

Background : Acute respiratory illnesses (ARIs) during childhood are often caused by respiratory viruses, result in significant morbidity, and have associated costs for families and society. Despite their ubiquity, there is a lack of interdisciplinary epidemiologic and economic research that has collected primary impact data, particularly associated with indirect costs, from families during ARIs in children.
Methods : We conducted a 12-month cohort study in 234 preschool children with impact diary recording and PCR testing of nose-throat swabs for viruses during an ARI. We used applied values to estimate a virus-specific mean cost of ARIs.
Results : Impact diaries were available for 72% (523/725) of community-managed illnesses between January 2003 and January 2004. The mean cost of ARIs was AU$309 (95% confidence interval $263 to $354). Influenza illnesses had a mean cost of $904, compared with RSV, $304, the next most expensive single-virus illness, although confidence intervals overlapped. Mean carer time away from usual activity per day was two hours for influenza ARIs and between 30 and 45 minutes for all other ARI categories.
Conclusion : From a societal perspective, community-managed ARIs are a significant cost burden on families and society. The point estimate of the mean cost of community-managed influenza illnesses in healthy preschool aged children is three times greater than those illnesses caused by RSV and other respiratory viruses. Indirect costs, particularly carer time away from usual activity, are the key cost drivers for ARIs in children. The use of parent-collected specimens may enhance ARI surveillance and reduce any potential Hawthorne effect caused by compliance with study procedures. These findings reinforce the need for further integrated epidemiologic and economic research of ARIs in children to allow for comprehensive cost-effectiveness assessments of preventive and therapeutic options.

Managed fund attributes and performance : Australian evidence

This cross-sectional study goes beyond the traditional performance evaluation of managed funds and extends the literature to consider fund-specific attributes that influence performance. Using a sample of 168 Australian open-ended equity funds, the risk adjusted performance is measured using three alternative evaluation techniques. We find that funds with higher management fees and long fund history have contributed to the underperformance. Along with the traditional attributes identified by the literature, market capitalisation of the security held by the fund is included as a unique attribute with significant results, indicating that funds targeting small capitalisation companies display superior performance.

Applicability of leisure theory in managerial views on volunteerism in a volunteer managed nonprofit organisation : some preliminary findings

This paper explores whether a leisure perspective explains volunteer  motivations as perceived by managers of one event-based nonprofit  organisation - Victoria’s Open Garden Scheme. The results identify that a leisure perspective does not explain all motivations, as some volunteers are socially motivated by a desire to give back to their community. Other  motivations are less positive and less voluntary than is expected of leisure and volunteering in a traditional context. Suggestions are made for further research and managerial implications in regards to managing volunteers.