Relative Efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal Samplers for Poaceae and Urticaceae Pollen under Field Conditions

Introduction: In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these differences inter-sampler correction factors may be applied, however for many pollen samplers and pollen taxa such correction factors do not exist and cannot be derived from existing published work. Materials and methods: In this study the relative efficiencies of the Burkard 7-Day Recording Volumetric Spore Trap, the Sampling Technologies Rotorod Model 20 and the Burkard Personal Volumetric Air Sampler were evaluated for Urticaceae and Poaceae pollen under field conditions, and the influence of wind speed and relative humidity on these efficiency relationships was assessed. Data for the two pollen taxa were collected during 2010 and 2011-12 respectively. Results: The three devices were found to record significantly different concentrations for both pollen taxa, with the exception of the 7-Day and Rotorod samplers for Poaceae pollen. Under the range of conditions present during the study wind speed was found to only have a significant impact on inter-sampler relationships involving the vertically orientated Burkard Personal sampler, whilst no interaction between relative efficiency and relative humidity was observed. Conclusions: Data collected with the three models of sampler should only be compared once the appropriate correction has been made, with wind speed taken into account where appropriate.

Creating Local Institutional Arrangements for Sustainable Wetland Socio-ecological Systems: Lessons from the ‘Striking a Balance’ Project in Malawi

Wetland socio-ecological systems provide livelihood benefits for many poor people throughout the developing world, yet their sustainable development requires local utilisation strategies that balance both environmental and development outcomes. Community-based local institutional arrangements that mediate peoples’ relationships with their environment and facilitate adaptive co-management offer one means of achieving this, and increasingly many NGOs and development practitioners have sought to integrate local institutional capacity-building into development projects. In the context of wider academic debates surrounding the long-term sustainability of externally-facilitated local institutions, this paper draws on the experiences of the three-year Striking a Balance (SAB) project in Malawi which sought to embed sustainable wetland management practices within community-based local institutional arrangements. Drawing on field data collected through participatory methods at three project sites some five years after the cessation of project activities, we examine the extent to which SAB’s local institutional capacity-building has been successful, and from this draw some lessons for externally-driven project interventions which seek win-win outcomes for people and the environment. With reference to Elinor Ostrom’s design principles for long-enduring common property resource institutions, we suggest that the observed declining effectiveness of SAB’s local institutions can be attributed to issues of stakeholder inclusiveness and representations; their sustainability was arguably compromised from their inception on account of them being nested within pre-existing, externally-driven village ‘clubs’ whose membership and decision-making was not congruent with all the wetland stakeholders within the community.