Termite and Ecosystem Processes: A Study from Western Ghats, South India

Termites are undoubtedly key soil organisms in tropical and subtropical soils. They greatly influence the physical, chemical, biological properties of soils and, consequently, water dynamics hence well known as “soil engineers”. Their effect on the ecosystem can be appreciated only if we have the detailed knowledge about the process and functions carried out by them in the tropical soil. Some studies from Africa and Vietnam gave a glimpse of services provided by the termite and under that particular vegetation but under Indian context, no such studies were conducted as result we don’t have much data regarding their effect on soil properties, water infiltration and vice versa. Hence, field studies were carried out to understand the effect of termite activity and the ecological benefits derived in terms of soil dynamics and water infiltration.The study was conducted at Uttara Kannada district located at the lavishing western ghat. Mound building termite species Odontotermes obesus, was considered as study species as it is the widespread and dominant termite species of the Indo-oriental region. Numerical density, mound height and soil properties of O. obesus mounds were only analysed along with the neighbouring soil without termite activity in forest areas. To assess the influence of the vegetation on termite mound properties, the forest types were classified into plantations, evergreen, semi-evergreen or deciduous. In the forest, termite active sites, as well as sites devoid of termite activity, were selected and the rate of water infiltration in these sites was also measured using Beerkan method. Bulk density and water humidity were measured. Data obtained were analysed. Results revealed that the amount of rainfall defined termite mound abundance, and it has a remarkable influence on the density/height of termite mounds. In terms of soil properties, clay and C content in the soil which is known to bring the stability to the termite mounds did not show any significant relationship with density or height of the termite mound. But a positive linear relationship was observed between clay content in termite mound walls and that in the surrounding topsoil. The result of water infiltration studies at the sites showed that there was a significant variation in the rate of water infiltration in the termite active sites. The study presented here is the important one as it aims towards the efficient determination of the functional influence of soil biodiversity (termites) in tropical ecosystem functioning and a better evaluation of their impacts on soil erosion and water dynamic at the local and global scale. Moreover, the link between soil biodiversity and ecosystem services, such as water availability and quality, is often mentioned but rarely demonstrated. This paper is therefore original in its approach and in it quantifies the importance of biodiversity on soil erosion, water dynamic and quality in tropical ecosystems. There is a clear lack of information on the functional impact of termites on ecosystem functioning in India, in comparison with Africa where most of the studies have been carried out. This study aims to counterbalance this trend through this paper.Keywords: Termites, Soil and water dynamics, Water infiltratio

Seasonal variation in the relative dominance of herbivore guilds in an African savanna

African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems

Trends in Loss to Follow-Up among Migrant Workers on Antiretroviral Therapy in a Community Cohort in Lesotho

BACKGROUND: The provision of antiretroviral therapy (ART) to migrant populations raises particular challenges with respect to ensuring adequate treatment support, adherence, and retention in care. We assessed rates of loss to follow-up for migrant workers compared with non-migrant workers in a routine treatment programme in Morjia, Lesotho. DESIGN: All adult patients (≥18 years) initiating ART between January 1, 2008, and December 31, 2008, and followed up until the end of 2009, were included in the study. We described rates of loss to follow-up according to migrant status by Kaplan-Meier estimates, and used Poisson regression to model associations between migrant status and loss to follow-up controlling for potential confounders identified a priori. RESULTS: Our cohort comprised 1185 people, among whom 12% (148) were migrant workers. Among the migrant workers, median age was 36.1 (29.6-45.9) and the majority (55%) were male. We found no statistically significant differences between baseline characteristics and migrant status. Rates of lost to follow up were similar between migrants and non-migrants in the first 3 months but differences increased thereafter. Between 3 and 6 months after initiating antiretroviral therapy, migrants had a 2.78-fold increased rate of defaulting (95%CI 1.15-6.73); between 6 and 12 months the rate was 2.36 times greater (95%CI 1.18-4.73), whereas after 1 year the rate was 6.69 times greater (95%CI 3.18-14.09). CONCLUSIONS: Our study highlights the need for programme implementers to take into account the specific challenges that may influence continuity of antiretroviral treatment and care for migrant populations

A Tale of Four Stories: Soil Ecology, Theory, Evolution and the Publication System

International audienceBACKGROUND: Soil ecology has produced a huge corpus of results on relations between soil organisms, ecosystem processes controlled by these organisms and links between belowground and aboveground processes. However, some soil scientists think that soil ecology is short of modelling and evolutionary approaches and has developed too independently from general ecology. We have tested quantitatively these hypotheses through a bibliographic study (about 23000 articles) comparing soil ecology journals, generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. FINDINGS: We have shown that soil ecology is not well represented in generalist ecology journals and that soil ecologists poorly use modelling and evolutionary approaches. Moreover, the articles published by a typical soil ecology journal (Soil Biology and Biochemistry) are cited by and cite low percentages of articles published in generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. CONCLUSION: This confirms our hypotheses and suggests that soil ecology would benefit from an effort towards modelling and evolutionary approaches. This effort should promote the building of a general conceptual framework for soil ecology and bridges between soil ecology and general ecology. We give some historical reasons for the parsimonious use of modelling and evolutionary approaches by soil ecologists. We finally suggest that a publication system that classifies journals according to their Impact Factors and their level of generality is probably inadequate to integrate "particularity" (empirical observations) and "generality" (general theories), which is the goal of all natural sciences. Such a system might also be particularly detrimental to the development of a science such as ecology that is intrinsically multidisciplinary

A systematic review of task- shifting for HIV treatment and care in Africa

BACKGROUND: Shortages of human resources for health (HRH) have severely hampered the rollout of antiretroviral therapy (ART) in sub-Saharan Africa. Current rollout models are hospital- and physician-intensive. Task shifting, or delegating tasks performed by physicians to staff with lower-level qualifications, is considered a means of expanding rollout in resource-poor or HRH-limited settings. METHODS: We conducted a systematic literature review. Medline, the Cochrane library, the Social Science Citation Index, and the South African National Health Research Database were searched with the following terms: task shift*, balance of care, non-physician clinicians, substitute health care worker, community care givers, primary healthcare teams, cadres, and nurs* HIV. We mined bibliographies and corresponded with authors for further results. Grey literature was searched online, and conference proceedings searched for abstracts. RESULTS: We found 2960 articles, of which 84 were included in the core review. 51 reported outcomes, including research from 10 countries in sub-Saharan Africa. The most common intervention studied was the delegation of tasks (especially initiating and monitoring HAART) from doctors to nurses and other non-physician clinicians. Five studies showed increased access to HAART through expanded clinical capacity; two concluded task shifting is cost effective; 9 showed staff equal or better quality of care; studies on non-physician clinician agreement with physician decisions was mixed, with the majority showing good agreement. CONCLUSIONS: Task shifting is an effective strategy for addressing shortages of HRH in HIV treatment and care. Task shifting offers high-quality, cost-effective care to more patients than a physician-centered model. The main challenges to implementation include adequate and sustainable training, support and pay for staff in new roles, the integration of new members into healthcare teams, and the compliance of regulatory bodies. Task shifting should be considered for careful implementation where HRH shortages threaten rollout programmes