Living Off Wetlands: A Case Study of Mara Bay and Masirori Wetlands, Tanzania

This study was undertaken to help highlight the negative impacts of economic activities on wetlands in East Africa with a specific focus on Mara Bay and Masirori wetlands, Tanzania, a region where the local communities still harness wetland resources for economic sustenance. Key economic activities and the negative impacts of the income-generating activities on the wetlands are identified, including the main goods harnessed, level of dependency of the locals to the wetlands, and the level of environmental knowledge of the locals on the wetlands’ ecosystem services. Both qualitative and quantitative tools and techniques viz.: questionnaires, semi-structured interviews, market surveys and spreadsheet analysis were used in this study. The proportion of wetland users involved in papyrus harvesting, food crop cultivation and fishing was 30%, 25% and 24%, respectively while charcoal/firewood and grass for livestock accounted for 12% and 7%, respectively. Significant differences in incomes for charcoal (p < 0.05) across the four villages were recorded but farming, fishing, mat making, herding and fish mongering were non-significant. About 6% of those interviewed had some considerable knowledge on wetland ecosystem services, while the rest (94%) lacked information. Issues identified as having detrimental impacts on the wetlands’ ecosystem services included conversion of sections of the wetlands into farmlands, grazing, charcoal burning, unsustainable fishing, overharvesting of papyrus and brick-making. Farming was found to be a major income-generating activity within the two wetlands. Other important economic activities were charcoal burning, fishing, mat making and fish mongering. The findings from the research are useful for devising appropriate strategies for wetland conservation. Such measures may include assigning wetland ecologists to the village governments, valuation of the wetlands, commissioning of a price and resource regulatory board for the wetland goods, creation of wetlands monitoring program, a fining regime system and a roll-out of mass environmental education in the wetlands regions.

Processes for the valorization of food and agricultural wastes to value‑added products:recent practices and perspectives

Biorefneries contribute to a circular bioeconomy using renewable feedstock to produce commodity and specialty chemicals as an alternative to petroleum chemicals.Using waste streams such as food waste and agricultural waste as a feedstock for biorefneries is a promising approach for obtaining value-added products in an economically feasible and sustainable way.The conversion of biomass to chemicals ofers diverse opportunities but poses new technological challenges.This paper aims to review the current state of food and agricultural waste valorisation by giving a brief technical overview,summarizing the current state of the bio-based market,and identifying the current barriers to scaling-up biorefneries.Utilizing lignocellulosic biomass in biorefneries calls for pre-treatment due to its complex structure,in which biomass is broken into monosaccharides,building blocks of value-added products.Diferent state of the art technologies for lignocellulose pre-treatment is introduced in the review followed by a brief explanation of the role of the hydrolysis and fermentation.The economic aspect of chemical production from biomass waste at an industrial scale is also introduced by giving an overview of some recent techno-economic studies.

Soil water storage,yield,water productivity and transpiration efficiency of soybeans(Glyxine max L.Merr)as affected by soil surface management in lle-Ife,Nigeria

Rainfed agriculture has a high yield potential if rainfall and land resources are effectively used.In this study,conventional(NC)and six in-situ water conservation practices were used to cultivate Soybean in 2011 and 2012 in Ile-lfe,Nigeria.The conservation practices are:Tied ridge(TR),Soil bund(BD),Mulch(ML),Mulch plus Soil bund(MLBD),Tied ridge plus Mulch(TRML),Tied ridge plus Soil bund(TRBD).The practices were arranged in Randomised Complete Block Design with four replicates.Seasonal rainfall was 539 and 761 mm in 2011 and 2012,respectively.Seasonal soil water storage(SWS)ranged from 485 mm for NC to 517 mm for TRML in the two seasons.ML increased the SWS in the upper 30 cm of the soil by 17% while TR increased the soil water content in the lower 30-60 cm by 22% compared with NC.ML reduced soil temperature in the upper 30 cm between 2.2 and 2.9℃ compared with NC,TR and TRML.Seasonal crop evapotranspiration ranged between 432 mm for NC and 481 mm for BD in the seasons.Grain yield increased by 41.7% and 44.3% for BD and MLBD,respectively compared with NC.Water conservation practices increased water productivity for grain yield by 14.0-41.8% compared with NC.Similarly,it increased average seasonal transpiration efficiency by 15.3-32.5% compared with NC.These findings demonstrate that when there are fluctuations in rainfall,in-situ water conservation practices improve SWS,land,and water productivity and transpiration efficiency of Soybeans.

Removal and recovery of nutrients and value‑added products from wastewater:technological options and practical perspective

Wastewaters from various process industries,namely food and agricultural,sugar mill,brewery,milk,vegetable and fruit,and meat and fsheries processing industries and their wastewater efuents contain nutrients,organic matter,inorganic,heavy metals,suspended solids,and pathogens.The discharges of non-treated wastewater enter the nearby aquatic ecosystem(e.g.,lakes,rivers)and are a signifcant concern due to the presence of diferent nutrients,competing ions and C containing pollutants.It causes excessive growth of algae,loss of habitat/species,and other negative impacts on human health/environment.In the present review,diferent treatment approaches have been discussed in utilizing these nutrients to synthesize value-added products such as biopolymer,biofuel,pigment,organic acid,or enzymes.These biopolymers can be used to prepare various food products/packaging materials.Dextran,chitosan,carrageenan,alginate,and pectin are good examples of non-food biopolymers.Besides these products,poly-β-hydroxybutyrate(PHB)synthesis from wastewater nutrients is reported as a new source of bio-nanocomposite materials/biopolymer-based coatings.In this review,the diferent treatment approaches are discussed,which are being used worldwide for the removal/recovery of nutrients,toxic pollutants,and the potential resource recovery of value-added products from wastewater.

The spatial variability of actual evapotranspiration across the Amazon River Basin based on remote sensing products validated with flux towers

Actual evapotranspiration(ET)is a major component of the water balance.While several international flux measurement programs have been executed in the tropical rain forest of the Amazon,those measurements represent the evaporative process at a few selected sites only.The aim of this study is to obtain the spatial distribution of ET,using remote sensing techniques,across the entire Amazon River Basin.Results from six global ET products based on remote sensing techniques(GLEAM,SEBS,ALEXI,CMRSET,MOD16,and SSEBop)were merged to obtain an ensemble prediction of the ET rates for the complex and in-accessible environment of the Amazon at a spatial resolution of 250 m.The study shows that the basinwide average ET is 1316 mm/year with a standard deviation of 192 mm/year.This new ET-Amazon product was validated against seven different historic flux tower measurements.The energy balance closure of the in situ measurements varied between 86 and 116%.Only months with more than 70%completeness of in situ measurements were considered for validation.Different procedures for closure correction were included in the analyses.The correlation between measured and remotely sensed ET is good(R2>0.97 for consecutive periods of 2 to 12months),and the bias correction is negligible for the energy balance residual method,which seemed most favorable.Monthly ET values have more uncertainty.The monthly RMSE values vary between 7.4 and 27.8 mm/month(the average RMSE is 22.2mm/month),and the coefficient of determination(R2)varies between 0.48 and 0.87(the average R2 is 0.53).The ET from the water balance is 1380 mm/year,being−64 mm/year difference and 4.6%less than ET derived from the water balance.The evaporation from the Amazon basin inside Brazil is 5063 km3/year,followed by Peru with 1165 km3/year.ET-Amazon shows more spatial details and accuracy than alternative global ET products such as LandFlux-EVAL,Model Tree Ensemble(MTE),and WACMOS-ET.This justifies the development of new regional ET products.