Vertical distribution of prokaryotes communities and predicted metabolic pathways in New Zealand wetlands, and potential for environmental DNA indicators of wetland condition

Globally, wetlands are in decline due to anthropogenic modification and climate change. Knowledge about the spatial distribution of biodiversity and biological processes within wetlands provides essential baseline data for predicting and mitigating the effects of present and future environmental change on these critical ecosystems. To explore the potential for environmental DNA (eDNA) to provide such insights, we used 16S rRNA metabarcoding to characterise prokaryote communities and predict the distribution of prokaryote metabolic pathways in peats and sediments up to 4m below the surface across seven New Zealand wetlands. Our results reveal distinct vertical structuring of prokaryote communities and metabolic pathways in these wetlands. We also find evidence for differences in the relative abundance of certain metabolic pathways that may correspond to the degree of anthropogenic modification the wetlands have experienced. These patterns, specifically those for pathways related to aerobic respiration and the carbon cycle, can be explained predominantly by the expected effects of wetland drainage. Our study demonstrates that eDNA has the potential to be an important new tool for the assessment and monitoring of wetland health.

Impact of multi-crop planter business on service providers’ livelihood improvement in some selected areas of Bangladesh

The custom hiring of the Versatile Multi-crop Planter (VMP) is a profitable enterprise for Local Service Providers (LSP) that could improve their household livelihood but the impacts have not yet been assessed in Bangladesh. In this study, we assessed the use pattern and profitability of custom-hiring the VMP, and its impacts on LSPs’ livelihood. A total of 18 LSP were purposively selected from Rajshahi, Thakurgaon, Mymensingh, and Rajbari districts for this study. The study revealed that LSPs effectively utilized VMP and 2-wheel tractor (2WT) for 4-6 months. They earned Tk. 1,42,434 (with incentive on VMP) and Tk. 1,36,134 (without incentive) per year as net income. The average payback periods were 0.72 and 0.98 years with and without incentive, respectively. The annual break-even of a VMP use was 7.79 ha. The LSPs reported a considerable cash (annual income increased by 34.9 %), and capital enhancement, e.g., land holdings (8.3 %), value of livestock (11.2 %), dwelling houses (36.6 %), household furniture (19 %), and modern amenities (45.5 %). The increased incomes from VMP custom hiring were mostly spent on nutritious food, land mortgage-in, and dwellings. The LSPs reported minor challenges such as being unable to use this machine in the wetland condition (61 %), no seating arrangement on the machine during operation in small plots (56 %), long time taken to complete sowing due to narrow planting width per pass (50 %), farmers’ skepticism about the planting machine as it is still new technology (44 %), and lack of skilled drivers (17 %). Financial support and technical assistance should be made available by the government for LSPs and local manufacturers to accelerate greater adoption of the VMP. Bangladesh J. Agril. Res. 44(3): 409-426, September 2019