Wetland Cultivation Research Articles

Molecular evidence reveals fish-pathogenic Aphanomyces spp. (Oomycetes: Saprolegniales) on new host of the threatened seasonal cyprinodont fish Nothobranchius spp. (Teleostei: Cyprinodontiformes) in south-eastern Democratic Republic of Congo

The Aphanomyces species pose an important global threat and cause damage to aquaculture and agriculture by infecting aquatic animals and plants. Several subpopulations of the seasonal cyprinodont fish genus Nothobranchius with lesions suggestive of infection with Aphanomyces invadans, were observed in ephemeral wetland habitats of the upper Congo drainage in the south-eastern Democratic Republic of Congo. Molecular analyses on samples collected in 2023 revealed evidence of fish-pathogenic oomycetes Aphanomyces invadans and A. laevis, for the first time in the host of fish genus Nothobranchius spp. All Nothobranchius fishes in the upper Congo drainage are subject to a high level of threat and belong to one of the threatened Red List categories, due to habitat degradation of seasonal wetlands. These fishes complete their seasonal life cycle in ephemeral natural habitats. The latter makes them highly vulnerable, as such wetland habitats are often degraded by the cumulative effect of multiple human stressors which include: the cultivation of wetlands for agriculture, the abstraction of water, the expansion of urban areas and the pollution load. Evidence of infection by oomycete pathogens documented in this study, represents a critical additional threat to the unique seasonal aquatic biodiversity of the region.

Evaluation of Newly Bred Zinc and Iron Enriched Rice Genotypes for Cultivation Under Aerobic Condition Using Genetic Parameters: Implication on Drought Management

This research focused on the evaluation of twelve newly bred rice genotypes with diverse morphological traits under aerobic cultivation to develop strategies for water conservation while maintaining grain productivity and quality. The experiment was conducted during the summer season of 2016, employing a Randomized Complete Block Design (RCBD) with wetland cultivation as a control. For analysis, various vegetative and reproductive traits namely, Plant height, Number of Tillers, Shoot Weight, Days to 50% flowering, Days to Maturity, Number of Productive Tillers, Panicle Length, Grain Weight, Length of the seed, Breadth of the seed, Ratio of Length and Breadth of the Seed, and Test weight of 100 seeds were recorded. Data on analysis of variance revealed the significant difference for days to flowering, maturity, plant height, panicle length, test weight, and grain yield under aerobic and wetland cultivation methods during the summer season, 2016, suggesting these traits are under high genetic control. Genetic parameters such as percentage of GCV, PCV, Heritability, and GAM were estimated across 13 parameters comprising vegetative and reproductive characters. The findings suggest a considerable amount of genetic variability for most traits, providing a foundation for the potential implementation of an effective selection procedure in breeding new rice varieties within the selected genotypes.

Faster cycling but lower efficiency: A microbial metabolic perspective on carbon loss after wetland conversion to cropland

Natural wetlands store 20–30% of soil organic carbon (C) in terrestrial ecosystems. Wetlands conversion to croplands has caused a massive loss of soil organic C; however, the microbial contribution to this C loss remains elusive. In this study, we took 24 soil cores from a natural wetland and a 23-year cultivated cropland over four seasons to compare the abundance of functional genes encoding 138 enzymes for ten C-cycling pathways classified as organic C degradation, catabolic and anabolic processes. We found that land use-induced C loss was primarily driven by enhanced organic C degradation (∼24% increase) but suppressed microbial C assimilation efficiency, represented by shifted catabolism and declined anabolism (∼22% decrease). The enhanced organic C degradation was advocated by the enriched genes encoding organic C degradation enzymes; the suppressed microbial C assimilation efficiency was upheld by the shifted catabolic processes and inhibited anabolic processes. Compared with natural wetlands, the croplands showed substantial shifts in catabolic processes - 22% suppression of the Embden-Meyerhof-Parnas pathway, 27% decline in the Citrate Cycle, 22% increase in Entner-Doudoroff, and 25% stimulation in pentose phosphate pathways. Meanwhile, the anabolic process, especially the Wood-Ljungdahl pathway, was significantly suppressed (∼55%) in the cropland. The shifts in organic C degradation, catabolism, and anabolism were stronger in spring and summer than in winter and autumn. At the ecosystem level, microbial metabolic quotient was suppressed by 44%, while microbial biomass carbon was boosted by 5% after wetland conversion to cropland, indicating a faster microbial growth rate but lower C use efficiency. Differentiating microbial metabolic processes explained the C loss after wetland cultivation, indicating an urgency to represent microbial metabolism in soil C models.

Farm size and productivity relationship among the farming communities in India

The relationship between farm size and productivity has been a topic of interest in agricultural research for decades due to the significance of agriculture in rural economies and its potential to reduce poverty and promote inclusive growth. The relationship between farm size and productivity is influenced by factors such as the type of crop being produced, costs of cultivation, farm management practices, access to inputs and markets and socio-economic conditions. This paper aims to investigate the relationship between farm size and productivity in the context of farming households, their cost of cultivation and the types of crops they produce. Using the Cobb–Douglas production function, the present study estimates the regression function for principal crops such as cotton and paddy in the study area. The findings reveal strong evidence of an inverse relationship between farm size and productivity, indicating that small and marginal farmers are more productive in wetland cultivation (paddy). In contrast, medium and large farmers are more productive in dry land cultivation (cotton). The paper also investigates the availability and accessibility of credit facilities for different farm sizes. It concludes that small and marginal farmers depend mainly on non-institutional credit agencies compared to medium and large farmers.

Soil nutrient and invertase-producing bacteria relation impact on Cilembu sweet potato (Ipomoea batatas L.) growth: A study based on upland and wetland cultivation in Cilembu village Sumedang district

Environment is one important factors that must be considered in supporting sweet potato productivity. Environmental factors can be biotic and abiotic, including the availability of nutrients and microbes in the soil. This study aimed to identify the nutrient content of the soil in paddy fields and dry fields, identify the total invertase microorganisms in paddy fields and dry fields, and identify the relationship between soil nutrients and microorganisms during the growth of Cilembu sweet potato in dry and paddy fields agroecosystems. This research was conducted on dry fields and paddy fields in Cilembu Village, Sumedang Regency. The experimental design used was a randomized block design (RBD) with six treatments and three replications: A; Rancing, paddy fields, B; Biang, paddy fields, C; Mencrang, paddy fields, D; Rancing, dry fields, E; Biang, dry fields, F; Mencrang, dry fields. The observed parameters included pH, C-organic, total-N, available-P, exchangeable-K, exchangeable-Na, exchangeable-Ca, and exchangeable-Mg, cation exchange capacity (CEC), and total invertase-producing bacteria. The results showed that in paddy fields, the pH was slightly acidic, and the nutrient content such as N, available P, exchangeable Ca, Mg, Na, CEC, and C-organic tended to be more available. Soil K and abundant invertase bacteria were more available in the dry fields. The activity of invertase bacteria had a close relationship with the K content. The information generated in this study could be used to determine an effective location to produce good quality sweet potato.

Inter-Island production variability and Pre-Contact carrying capacity estimates: A geospatial analysis of taro farming in Rurutu, (Austral Islands, French Polynesia)

Our study explores pre-contact taro cultivation in pondfield irrigation systems on Rurutu (Austral Islands, French Polynesia). Understanding the size and extent of these systems is critical for estimating pre-contact human population, the ability to produce surplus, and socio-political dynamics. Since peak taro cultivation occurred across Polynesia prior to its historic documentation, the extent of wetland cultivation must be estimated from other sources. We explore pre-contact ecology and population levels on Rurutu using Landsat imagery and geospatial suitability analysis to estimate the maximum extent of the island’s pondfield irrigation systems. A primary goal was to develop an intra-island comparison of probable annual yields of taro to model pre-contact population sizes and their distribution at the system and socio-political district scales. Our model indicates the likely presence of 20 dormant taro systems on Rurutu. Our results point to significant intra-island differences of taro production on the island in the pre-contact era. We suggest that Rurutu’s Open socio-political structure was maintained, in part, by unequally dispersed arable taro land throughout the island which contributed to intra-island differences in annual yields and population densities resulting in endemic pre-contact warfare. We end by linking our data to ongoing conversations regarding resilience in Oceania and beyond.

Agricultural land use regulates the fate of soil phosphorus fractions following the reclamation of wetlands

Over half of the Earth's wetlands have been reclaimed for agriculture, leading to significant soil P destabilization and leaching risks. To evaluate the effects of agricultural land use on soil P stability, we used sequential P extraction to investigate the long-term effects of wetland cultivation for rice and soybean on soil P fractions, including labile and moderately labile inorganic/organic P (LPi, LPo, MPi, and MPo), and stable P in Northeast China. The results showed that soybean cultivation decreased the total P by 35.9 %, whereas rice cultivation did not influence the total P content (p < 0.05). Both the soybean and rice cultivations significantly increased LPi (p < 0.05). Soybean cultivation significantly decreased the LPo and MPo compared to rice cultivation, and the latter increased MPi by 309.28 % compared with the reference wetlands (p < 0.05). Redundancy analysis indicated that pH, poorly crystalline Fe (Feca), crystalline Fe (Fec), and total organic carbon (TOC) explained similar variations in P fractions during soybean and rice cultivation (54.9 % and 49.7 %, respectively). Similarly, during soybean or rice cultivation, pH negatively influenced LPo and MPo, while Feca positively influenced MPi and LPi. Furthermore, TOC showed a positive role in LPo, and MPo, but a negative effect on LPi and MPi during rice cultivation. Hence, we concluded that the cultivation of soybean or rice create contrasting modifications to wetland soil P fractionation by altering TOC, Feca, Fec, and pH. Our study indicates that agricultural land use can regulate the fate of wetland soil P fractionation, with potential benefits to both i) P risk management in cultivated wetlands and ii) potential approaches for future wetland restoration.

Microbial mechanisms for methane source-to-sink transition after wetland conversion to cropland

Wetland conversion to cropland substantially reduces methane (CH4) emission, turning a source into a sink on many occasions; how various microbial processes contribute to this source-to-sink transition remains elusive. We addressed this issue by examining the net CH4 flux, CH4 production potential, CH4 oxidation potential, and functional genes associated with methanogenesis and methanotrophy in a pristine wetland and a 23-year cultivated cropland in the Sanjiang Plain, China. The study confirmed that wetland conversion to cropland turned a CH4 source of 44.93 ± 10.17 g CH4·m−2·yr−1 to a small CH4 sink of −0.056 ± 0.051 g·CH4 m−2·yr−1. The proportion of total CH4-related genes, methanogenesis genes, as well as the CH4 production marker genes – mcr were significantly decreased by 24.14 %, 32.10 %, and 97.89 %, respectively in cropland. The proportions of methanotrophic marker genes, pMMO, and the sum of sMMO and pMMO were significantly increased by 48.74 % and 22.79 % after wetland cultivation. The 23-year cultivation yielded suppressing impacts on methanogenesis and mcr genes throughout the four seasons while stimulating effects on the functional genes of sMMO, pMMO, and MMO in spring and summer. The proportions of CH4-related genes decreased along soil depth in wetland and cropland, while pMMO and MMO slightly increased in the depth of 20–60 cm in cropland. A global synthesis supported this microbial mechanism for the CH4 source-to-sink transition, indicating the strong methanogenesis suppression and slight methanotrophy enhancement in explaining the source-to-sink transition after wetland conversion to cropland. This mechanism should be incorporated into CH4 models to predict CH4 dynamics under land-use change.

Paludiculture: peatland utilization to support climate change adaptation

Tropical peatlands are one of the largest carbon-storing ecosystems in the world. Draining tropical peatland causes environmental damage including greenhouse gas emissions. Drained peat is highly susceptible to fires that increase carbon emissions into the air. Rewetting is one way to solve the problem because, to achieve a zero or negative carbon balance, the water level should be close to or above the surface to maintain the water saturation of peat. The government of Indonesia has thoughtfully restored the peatland by implementing the 3R approach (rewetting, revegetation, and revitalizing local livelihood). After rewetting, paludiculture (wetland cultivation) is a promising land-use option for peatland. Through paludiculture, the peatland ecosystem will be improved which has already undergone drainage and will re-encourage carbon accumulative in peatland. This paper aims to determine the potential of paludiculture to support climate change adaptation including presenting challenges and opportunities in its implementation. Paludiculture has been shown to reduce greenhouse gas emissions by keeping peat moist. Besides having an ecological function, paludiculture also functions economically because it can be an alternative source of livelihood for people living around peat.

Agronomic Response of Local Upland Rice Cultivars on Growing under Two Cultivation Systems

Background: This study aimed to observe the agronomic response of 18 Southeast Sulawesi local upland rice cultivars that were grown under two cultivation systems (dry land and wet rice field) and optimize local potential to support self-sufficiency and food security. Methods: The research used a split-plot design with the following main plot: cultivation system (L) including upland (L1) and rice field cultivation system (L2). The subplots were 18 local upland rice cultivars such as Wangkomina (K1), Wuna Lapodidi (K2), Waburi-buri (K3), Wapantoga (K4), Nggalaru (K5), Wuna Parigi (K6), Bakala (K7), Biu (K8), Ikulaku (K9), Bou (K1), Momea (K11), Daindomoronene (K12), Konkep (K13), Tinangge (K14), Ndoamoito (K15), Uwa (K16), Ndowatu (K17) and Indalibana (K18). Result: The local upland rice responded better to the wetland cultivation system than the upland cultivation system. The local upland rice cultivar Ndowatu showed the highest production potential, which was statistically similar to the Biu, Ikulaku, Momea, Konkep and Uwa cultivars. Ndowatu cultivar showed high production potential (842.80 g.m-2). Thus, this cultivar can be considered suitable for development in the rainfed lowlands to increase the planting index and to support the self-sufficiency and food security of the region.

A review of the conservation status of seasonal Nothobranchius fishes (Teleostei: Cyprinodontiformes), a genus with a high level of threat, inhabiting ephemeral wetland habitats in Africa

Abstract The small and colourful Nothobranchius fishes inhabit ephemeral habitats in freshwater wetlands of Africa and have extreme life‐history adaptations that allow their eggs to survive the periodic drying up of the seasonal natural habitats. They are subject to high levels of threat, with 72% of the 94 assessed species falling into one of the threatened Red List categories, as a consequence of habitat degradation of seasonal wetlands. There is, therefore, a need to conserve ephemeral waters for species that rely on the seasonality of habitats. Extinction risk factors for all species of the genus were entirely reworked with IUCN Red List assessments, whereas first‐time assessments were established for species that had previously not been evaluated. These fishes complete their seasonal life cycle in ephemeral natural habitats and this makes them highly vulnerable, as such wetland habitats are often degraded owing to multiple interacting human‐induced stressors and threats, including cultivation of wetlands for agriculture, abstraction of water, expansion of urban areas and pollution load. A fine‐scale classification scheme based on habitat type was used for each site to identify ecological characteristics and the pattern of threats. The classification scheme is based on a primary subdivision of natural habitats compared with those modified by human activities, with further subdivision within the two fundamental groupings. Out of the 478 analysed habitat site observations by the authors, 46% were affected by human activities. Recommended conservation actions include: conducting surveys to better understand habitat trends and threats; establishing protected areas and effectively allocating resources to preserve wetland habitats; managing protection of the structural integrity of the habitats throughout the seasonal phases of wet and dry seasons; and raising awareness of the importance of healthy wetland systems and the value of the unique seasonal freshwater biodiversity.

Enhancing soil ecosystem services through sustainable integrated nutrient management in double rice-cropping system of North-East India

The wetland cultivation of rice is subjected to anaerobic and aerobic soil conditions causing substantial changes in the soil system. However, how long-term supplementation of organics with reduced chemical fertilizers affects microbial composition, their activities, and enzymatic activities in acid soil has not been sufficiently investigated. This research is focused on a rice-rice system after an ongoing field experiment set-up in 1977–78 at Assam Agricultural University, Jorhat, India, where 7 alternative nutrient management have been investigated to: (1) assess the effects on soil organic carbon (SOC), microbial biomass carbon, and enzymatic activity in acid soil; (2) identify and discuss the most suitable treatment combinations of organic and chemical fertilizers to enhance soil ecosystem services (SES). Accordingly, we analysed the soil microbiological properties as affected by the 32 years of continuous integrated nutrient management (INM) practices and also evaluated the INM treatments in terms of SES. Results revealed that the soil microbial biomass carbon significantly varied across the treatments from 129.4 to 412.1 µg g−1 which comprises 2.4 to 4.4% of the SOC. The highest bacterial count (8.95 log cfu g−1 soil) was recorded in RDF + Azolla treatment, whereas fungal count was the maximum (7.47 log cfu g−1 soil) in RDF + FYM treatment. All the enzymatic activities responded significantly to the INM practices, but the trend of response was different for different enzymes. The highest dehydrogenase (223.6 µg TTF g−1 soil 24 h−1) and urease (4.1 μg NH4-N g−1 soil 2 h−1) activities were recorded in RDF + Azolla, while phosphomonoeaterase (337.4 μg p-nitrophenol g−1 soil h−1) and fluorescein diacetate hydrolysis (10.0 μg fluorescein g−1 soil h−1) activities were found to be the maximum in RDF + FYM. The microbial and enzymatic activities decreased significantly in the control after 32 cycles of rice-rice cropping. In this study, a significant positive statistical correlation of all the microbiological properties with soil pH, soil organic carbon and grain yield of crops were recorded. Finally, the different soil properties under the different nutrient treatments have been discussed in terms of SES provision, highlighting that the most sustainable treatments have resulted in RDF + FYM, RDF + RS and RDF + Azolla.

Assessing the Long-Term Ecological Sustainability of Dambo Cultivation in Southern Africa: Ten-Year Case Studies from Zambia and Malawi

Internationally, evidence-based assessments of the sustainability of cultivation in seasonal wetlands are lacking despite such areas, including dambos in southern Africa, providing key areas for cultivation. The Striking a Balance project, which supported multiple use, including cultivation, of dambos, was undertaken in Zambia and Malawi between 2006 and 2008. Using the baseline WET-SustainableUse assessments made in 2008 in four of these dambos, the procedures were repeated in 2019 to explore the ecological sustainability of current use based on the concept of Thresholds of Potential Concern (TPC). This concept was applied to the five components of ecological health, namely hydrology, geomorphology, soil organic matter, nutrient retention and vegetation composition. In all four dambos, despite ten years of multiple use including cultivation, the change in ecological health between 2008 and 2019 was generally small, and overall, the ecological health of the four dambos has largely been maintained. However, there are some concerns, particularly with respect to vegetation composition, which had fallen below the TPC for two of the dambos. The methods used and the findings appear to have wider application in Africa for long-term monitoring the ecological health of seasonal wetlands and determining the ecological bounds for wetland cultivation.

Ecological and Environmental Effects of Estuarine Wetland Loss Using Keyhole and Landsat Data in Liao River Delta, China

An estuarine wetland is an area of high ecological productivity and biodiversity, and it is also an anthropic activity hotspot area, which is of concern. The wetlands in estuarine areas have suffered declines, which have had remarkable ecological impacts. The land use changes, especially wetland loss, were studied based on Keyhole and Landsat images in the Liao River delta from 1962 to 2016. The dynamics of the ecosystem service values (ESVs), suitable habitat for birds, and soil heavy metal potential ecological risk were chosen to estimate the ecological effects with the benefit transfer method, synthetic overlaying method, and potential ecological risk index (RI) method, respectively. The driving factors of land use change and ecological effects were analyzed with redundancy analysis (RDA). The results showed that the built-up area increased from 95.98 km2 in 1962 to 591.49 km2 in 2016, and this large change was followed by changes in paddy fields (1351.30 to 1522.39 km2) and dry farmland (189.5 to 294.14 km2). The area of wetlands declined from 1823.16 km2 in 1962 to 1153.52 km2 in 2016, and this change was followed by a decrease in the water area (546.2 to 428.96 km2). The land use change was characterized by increasing built-up (516.25%), paddy fields (12.66%) and dry farmland (55.22%) areas and a decline in the wetland (36.73%) and water areas (21.47%) from 1962–2016. Wetlands decreased by 669.64 km2. The ESV values declined from 6.24 billion US$ to 4.46 billion US$ from 1962 to 2016, which means the ESVs were reduced by 19.26% due to wetlands being cultivated and the urbanization process. The area of suitable habitat for birds decreased by 1449.49 km2, or 61.42% of the total area available in 1962. Cd was the primary soil heavy metal pollutant based on its concentration, accumulation, and potential ecological risk contribution. The RDA showed that the driving factors of comprehensive ecological effects include wetland area, Cd and Cr concentration, river and oil well distributions. This study provides a comprehensive approach for estuarine wetland cultivation and scientific support for wetland conservation.

Analysis of different urban spaces on thermal comfort in cold regions: a case from Erzurum

With the rapid rise in population density in urban areas, there has also been an increase in research on quality of life and the effects of green space on health and comfort in densely populated cities. A critical part of improving the quality of life in urban areas is the reduction of urban heat island effect, especially in hot climate cities, and the reduction of adverse effects of winter in cold climates. Urban planning and landscape design strategies can have a great impact on urban microclimates, thereby providing relief from the harsh effects of climate change. Studies reveal that the cultivation of wetlands and open green spaces can have a direct impact on microclimate and comfort in densely populated areas. Erzurum is under the cold stress of the decreasing temperature in winter and continues to experience extreme temperatures in summer. This study is focused on the effects of urban design and landscape architectural interventions in the city of Erzurum. For this purpose, meteorological stations were placed in intensive construction areas of the urban city center, in wetland areas, and in the forested area of Ata Botanical Park in the city center. Three stations, dense green areas (1), temporary wetlands (2), and urban city center areas (3), were selected as urban area use types. Meteorological data were collected during March–April when the wetlands were full due to heavier periods of rain, and during July–August, the hottest months in the city. Thermal comfort values have been analyzed for different areas using RayMan soft model. The average value of Physiologically Equivalent Temperature (PET) recorded in March–April was 3.5 °C in the city center, 2.8 °C in the dense green area, and − 0.3 °C around the temporary wetland area. In July and August, the average value of PET in the city center was 24.9 °C, 23.0 °C in dense green areas, and 21.2 °C around the wetland area. In cold cities, it was found that the water surfaces, which positively contribute to thermal comfort in summer, increased the cold stress in winter. It was determined that dense green areas function as balancing factors for thermal comfort of the city both for summer and winter seasons and they contributed positively in all conditions. As a result of this study, more accurate decisions can be made for future urban planning efforts by considering the effects of different environmental conditions on microclimates in the city, especially where this consideration can be applied to urban design and development, urban revitalization efforts, or when designing new settlements.

Socio-Economic Determinants of Land Use/Cover Change in Wetlands in East Africa: A Case Study Analysis of the Anyiko Wetland, Kenya

In East Africa, wetlands are steadily converted to agriculture for food security reasons. This study analyzed high spatial resolution panchromatic and color photographs in the Anyiko wetland in Kenya to reveal wetland conversions between 1966 and 2018. In addition, socio-economic determinants of land use/cover change are assessed in the Anyiko wetland. Socio-economic data was collected through a questionnaire survey of 226 households. A CHi- squared Automatic Interaction Detector (CHAID) decision tree approach is utilized to assess determinants of wetlands conversion. The results showed that between 1966 and 2018, the wetland area reduced by 55%, mostly attributed to agricultural development. Households were more likely to cultivate the wetland if they did not harvest papyrus for artisanal products, were male-headed and lacked alternative sources of income. The perceptions that wetland is “wasteland” and conversion to agriculture provides higher net monetary benefit did not influence wetland cultivation. Hence, the conversion of the wetland was determined by the socio-economic status of the households rather than perceptions on its value.

Land use change effects on diversity of soil bacterial, Acidobacterial and fungal communities in wetlands of the Sanjiang Plain, northeastern China

The bacterial, acidobacterial, and fungal communities in wetlands can undergo perturbations by various human activities, such as disturbances caused by cultivation and during the process of system restoration. In this study, we investigated the relationships between the composition of the soil bacterial, acidobacterial, and fungal communities and the transformation of wetlands by human activities in the Sanjiang Plain. Soil microbial communities were assessed in wetland soils collected from pristine marsh, neighboring cropland (wetland turned into arable land), and land that had been reforested with Larix gmelinii. The alpha-diversities of bacteria, Acidobacteria, and fungi were affected by land-use change and were highest in the arable land and lowest in the wetland soils. The soil microbial community structures were also altered with changing land-use. Canonical correlation analyses showed that beta-diversity was significantly affected by soil pH, available phosphorus, soil nitrogen, and total organic carbon. Overall, our results showed that the agricultural cultivation of wetlands changes the available soil carbon, nitrogen, and phosphorus pools, thereby influencing the bacterial, acidobacterial, and fungal diversity and community structure. Once the soil microbial community has been altered by human activity, it might be difficult to restore it to its original state. These findings highlight the importance of effectively maintaining the diversity of soil bacterial, Acidobacterial, and fungal communities despite land use change in order to sustain a microbial community diversity and ecosystem function.

Characterizing Land Use Systems within Awoja Watershed

This manuscript analyses trends in land use changes in Awoja Watershed with the aim of exploring the underlying causes of degradation in this watershed within the context of frequent draughts and floods. Changing trends of land use characteristics were used as indicators of ineffectiveness of control of access to resource use in the watershed. The study was carried out in the districts of Katakwi, Amuria and Sorotiin Eastern Uganda where the watershed is experiencing increasing trends of degradation despite the presence of elaborate watershed management institutions. The study used Remote Sensing, and focus group discussions to acquire relevant data on land use changes and their perceived causes. Perceptions of respondents on the effectiveness of the local governance processes were generated. The findings show increase in built-up areas from 0.21% between 1986-1996; to 3.28 between 2006 and 2016 and a notable decrease in forest cover from 107.48 Km2 in 1,986 to 6.94 Km2 by 2016. The results also show a dramatic increase in small scale farming area from 629.44 Km2 to 2,376.64 Km2 from 1986-2016 while the area of wetland reduced from 2,810.47 Km2 to 1,355 Km2over the same period. Results from focus group discussions revealed that although climatic and demographic factors were responsible for land use changes in Awoja, control of access to natural resources was inadequate to stop degradation. Climatic factors mentioned included increased frequency of floods and draughts that were perceived to have been responsible for changes in vegetation cover, water levels and infrastructure. Socio economic factors driving the changes in land use included increased cultivation of wetlands and communal land, increased sale of fuel wood, charcoal and sand, increased migration of cattle herders into the watershed during draughts and out of it during floods and increased fishing. While climatic factors were important, socio political factors such as displacements of communities, resettlements in the fragile environment brought about by government efforts to demarcate wetlands and wild life conservation areas were cited as drivers of degradation. The study concludes that besides climatic factors, inadequate management of access to resources was contributing to degradation of the watershed.

Changes of microbial residues after wetland cultivation and restoration

A potentially important factor for destabilization of soil organic C (SOC) in the conversion of ecosystems to arable land is the impact to microbial residues, which have been recently shown to be a significant source of SOC pool. Here, we present the results of a study investigating the changes of microbial residues along a chronosequence of cultivation (5, 15, and 25 years) and attempted restoration (6 and 12 years of agricultural abandonment) in a marsh wetland of China. The wetland cultivation depleted the fraction of SOC derived from microbes, in particular fungal residues. During agricultural abandonment and restoration, bacterial residues accumulated relatively more rapidly than fungal analogs, where fungal residues represented the major microbial SOC pool overall. These differential responses of microbial residues are illustrative of the susceptibility of this SOC pool and indicate their importance as a tool to track soil stability with land-use change. Our work points to the need for future research to focus more strongly on the nature and mechanisms of microbial residue–mediated C process during chronic land-use changes.

The potential contribution of peri-urban wetlands to livelihood of local communities in Shinyanga Municipality, Tanzania

Yusuph M, Munishi PKT. 2018. The potential contribution of peri-urban wetlands to the livelihood of local communities in Shinyanga Municipality, Tanzania. Bonorowo Wetlands 2: 75-83. The study took place in Shinyanga Municipality, Tanzania to assess the potential contribution of peri-urban wetlands to the livelihood of nearby communities. The specific objectives were to examine the participation of the suburban wetland ecosystems to natural capital-(food production/food security), evaluate the involvement of periurban wetlands ecosystem to financial capital-(household income) and assess the advantages received by farmer groups/associations formed around the utilization of wetlands (social capital). Information was acquired through households and farmer's group/associations questionnaires, focus group discussion as well as field observations. Data were analyzed by employing descriptive and inferential statistics by applying correlation and t-test. As many as 79.2% of the wetland nearby communities rely on the wetlands for food. The major food crops were paddy, fruits, vegetables, and sweet potatoes. The average production levels of cereals, vegetables and fruits were prominently higher in wetlands compared to uplands. In the case of household income wetland cultivation (paddy, vegetables, maize, and fruits) brought about statistically higher household annual mean income of Tshs 2,335,852/year (US$ 1,168) compared to Tshs 197,475/year (US$ 99) produced by upland cultivation. The results further suggested that 70% of the farmer groups/associations established around wetland utilization accessed loans/credit to support agricultural production as an advantage from being members. Sustainable use of peri-urban wetlands in Shinyanga Municipality produces substantial livelihoods to adjacent communities. Conservation of such wetland ecosystems is indispensable for continued contribution to livelihoods while ensuring environmental protection. Further studies are necessary to unravel the nature of social capital associated with utilization of wetland ecosystems.