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Snails are the first intermediate host in the life cycle of trematodes. Previous research found that Trichopodus microlepis fish, cultured in earthen ponds in Tan Nhut Commune, Binh Chanh District, Ho Chi Minh City, Vietnam had a high infection rate with metacercariae of Centrocestus formosanus and Procevorum sp. It is necessary to investigate whether habitats supplying water to the ponds may contribute to the transmission by carrying intermediate hosts and/or cercariae into these ponds or not. A study of cercariae and snail composition in rice fields and canal supplying water directly to these Trichopodus microlepis ponds was carried out with six samplings in the years 2022 and 2023. A total of 1,151 snails were collected, and nine snail species belonging to 8 genera and 6 families were identified. Three snail species in both rice fields and canal were infected with trematode (cercariae stage) including Bithynia siamensis, Lymnaea viridis and Indoplanorbis exustus. The overall prevalence in the dry season (25.9%) was significantly higher than in the wet season (10.6%) (P<0.05). Three cercariae morphotypes were recovered from snails: xiphidio (in all three snails), echinostome (in Lymnaea viridis and Indoplanorbis exustus), and pleurolophocercous in Bithynia siamensis. This finding shows that Bithynia siamensis is one of the infected sources for Trichopodus microlepis fish cultured in ponds, as pleurolophocercous is also the cercariae in the family of Heterophyidae (including Centrocestus formosanus and Procevorum sp.). Further research should be done to clarify the transmission of fish-borne zoonotic diseases to cultured Trichopodus microlepis in other habitats including the actual fishponds, and sources of trematodes in order to produce Trichopodus microlepis free of metacercariae, contributing to clean aquaculture development and

Although rice production landscapes are often the scene of homicides, vertebrate decomposition and associated arthropods have never been described from rice paddies. Tropical rice landscapes are typically composed of irrigated/non-irrigated rice fields, fallow land (i.e., uncultivated fields), and low earthen levees (bunds) used as access pathways. The specific microclimatic and environmental conditions associated with each subunit of rice field landscapes are likely to impact carcass decomposition as well as the arthropod species associated with carrion. Here, we tested the hypothesis that the combined effects of constraints on arthropod colonization and survival, scarcity of necromass, limited habitat architecture, and recurrent disturbance limit the ability of carrion-related arthropods to colonize corpses and large carcasses in tropical rice-fields. Our results from monitoring pig carcasses in Philippine rice fields indicated that vertebrate decomposition in irrigated fields was slower and incomplete when compared to non-irrigated fields and bunds. Carcasses were colonized by a small complex of carrion-related arthropods that differed in composition and relative species abundance between dry bunds and relatively humid rice paddies. Fire ants (Solenopsis germinata) were observed frequently on carcasses exposed on bunds, rarely in non-irrigated fields, and almost never in irrigated fields. The presence of fire ants was associated with reduced blow fly (Chrysomya megacephala) abundance. Taken together, this indicates that the arthropod fauna associated with carcasses in tropical rice fields is relatively simple in contrast to the generally high arthropod diversity reported for other ecosystems at tropical latitudes. The limited richness of the community also means that an understanding of the development of one abundant calliphorid blow fly, C. megacephala, may be sufficient to investigate deaths and homicides under conditions similar to the ones described in th

Aims: Research into the dispersal of plants lacking a fleshy fruit by avian endozoo-chory remains limited, particularly regarding the different roles of specific vectors in the same habitat.Methods: We compared plants dispersed by endozoochory between two migratory waterbirds differing in body size: the lesser black-backed gull Larus fuscus, and the white stork Ciconia ciconia. We collected faeces and pellets from roosting flocks on dykes in rice fields in Doñana, SW Spain, and extracted intact seeds.Results: We recovered 424 intact seeds from excreta, representing 21 plant taxa, 11 of which germinated under laboratory conditions. Eight plant species are con -sidered weeds, four of them as alien species, and only two have a fleshy fruit. Seed abundance and species richness per sample did not differ between storks and gulls. Toadrush (Juncus bufonius) was the dominant species, accounting for 49% of seeds recovered. PERMANOVA and mvabund analyses revealed no differences in the pro -portions of each plant species dispersed by the two vectors, and seasonal variation in abundance was absent. Overall, germinability was 19%, and declined with increasingdelay between sample collection and processing. Transects along dykes identified 52 plant taxa, only 18 of which were recorded in excreta.Conclusions: Overlap in the communities of non-fleshy-fruited plants dispersed by two unrelated birds of different size suggests that waterbird plant dispersal networks are different from frugivore networks. Unlike for frugivores, decoupling between seed production and ingestion reduces seasonal variation in endozoochory rates. For Juncus bufonius and other plants, these avian vectors provide maximum dispersal distances several orders of magnitude greater than predicted from their dispersal syndromes. Endozoochory by migratory waterbirds has major implications for plant distributions in a rapidly changing world, and more research is required before we can predict which plants disperse regu

Aims: Research into the dispersal of plants lacking a fleshy fruit by avian endozoo-chory remains limited, particularly regarding the different roles of specific vectors in the same habitat.Methods: We compared plants dispersed by endozoochory between two migratory waterbirds differing in body size: the lesser black-backed gull Larus fuscus, and the white stork Ciconia ciconia. We collected faeces and pellets from roosting flocks on dykes in rice fields in Doñana, SW Spain, and extracted intact seeds.Results: We recovered 424 intact seeds from excreta, representing 21 plant taxa, 11 of which germinated under laboratory conditions. Eight plant species are con -sidered weeds, four of them as alien species, and only two have a fleshy fruit. Seed abundance and species richness per sample did not differ between storks and gulls. Toadrush (Juncus bufonius) was the dominant species, accounting for 49% of seeds recovered. PERMANOVA and mvabund analyses revealed no differences in the pro -portions of each plant species dispersed by the two vectors, and seasonal variation in abundance was absent. Overall, germinability was 19%, and declined with increasingdelay between sample collection and processing. Transects along dykes identified 52 plant taxa, only 18 of which were recorded in excreta.Conclusions: Overlap in the communities of non-fleshy-fruited plants dispersed by two unrelated birds of different size suggests that waterbird plant dispersal networks are different from frugivore networks. Unlike for frugivores, decoupling between seed production and ingestion reduces seasonal variation in endozoochory rates. For Juncus bufonius and other plants, these avian vectors provide maximum dispersal distances several orders of magnitude greater than predicted from their dispersal syndromes. Endozoochory by migratory waterbirds has major implications for plant distributions in a rapidly changing world, and more research is required before we can predict which plants disperse regu

Aims: Research into the dispersal of plants lacking a fleshy fruit by avian endozoo-chory remains limited, particularly regarding the different roles of specific vectors in the same habitat.Methods: We compared plants dispersed by endozoochory between two migratory waterbirds differing in body size: the lesser black-backed gull Larus fuscus, and the white stork Ciconia ciconia. We collected faeces and pellets from roosting flocks on dykes in rice fields in Doñana, SW Spain, and extracted intact seeds.Results: We recovered 424 intact seeds from excreta, representing 21 plant taxa, 11 of which germinated under laboratory conditions. Eight plant species are con -sidered weeds, four of them as alien species, and only two have a fleshy fruit. Seed abundance and species richness per sample did not differ between storks and gulls. Toadrush (Juncus bufonius) was the dominant species, accounting for 49% of seeds recovered. PERMANOVA and mvabund analyses revealed no differences in the pro -portions of each plant species dispersed by the two vectors, and seasonal variation in abundance was absent. Overall, germinability was 19%, and declined with increasingdelay between sample collection and processing. Transects along dykes identified 52 plant taxa, only 18 of which were recorded in excreta.Conclusions: Overlap in the communities of non-fleshy-fruited plants dispersed by two unrelated birds of different size suggests that waterbird plant dispersal networks are different from frugivore networks. Unlike for frugivores, decoupling between seed production and ingestion reduces seasonal variation in endozoochory rates. For Juncus bufonius and other plants, these avian vectors provide maximum dispersal distances several orders of magnitude greater than predicted from their dispersal syndromes. Endozoochory by migratory waterbirds has major implications for plant distributions in a rapidly changing world, and more research is required before we can predict which plants disperse regu

The Natural Park of the Albufera (Valencia, Spain) is a Mediterranean wetland where rice cultivation dominates the agricultural activity. The purpose of this study was to offer broader information about the current state of the wetland assessing the contamination by pesticides in four aquatic habitats during the rice cultivation period in 2016. Liquid chromatography with tandem mass spectrometer (UHPLC-MS/MS) was used to determine the pesticides in water and sediment samples from the rice fields, Lake Albufera and irrigation and outlet channels. 21 pesticides were detected in our samples (seven already forbidden by European legislation). Higher values than 10000 ng L of accumulated pesticides had been observed in the water samples of the midterm of the cultivation period (July). The sediment samples presented values ten times lower than the water samples. The habitat showed significant differences in the concentrations of the water and sediment samples (Two-way Permanova, p < 0.05) at the end and in the midterm of the cultivation period, respectively. Bentazone and tricyclazole were the dominant and most ubiquitous pesticides in the habitats. The quantities also calculated in real water volume showed that the rice fields and Lake Albufera supported more than 100 kg of pesticides in July. Finally, negative effects in the phytoplankton and some taxa of the biota of the Natural Park were predicted in the risk assessment (Risk Quotient >1). The data provided in this work should show concern about the impact of pesticides in Mediterranean systems subjugated to agricultural pressure.

© 2020 Elsevier Ltd The analysis of macroinvertebrate communities is essential in aquatic ecology studies. Nonetheless, sample collection, processing and species determination of macroinvertebrates are extremely time-consuming and require huge efforts. Moreover, despite the crucial need for refined sampling protocols, investigations on viable benchmark sampling efforts are still scarce. This study provides a preliminary analysis on the optimisation of the sampling effort required to study macroinvertebrate communities from rice fields. Twenty core sediment samples were collected from a non-vegetated Mediterranean lagoon (rice field) in Valencia (Spain), and their macroinvertebrate community assemblages were obtained. Characterisations of the minimum number of samples needed for both faunistic inventories and environmental quality assessments were carried out using diversity indexes (number of taxa, Shannon, Simpson, and Margalef indexes), ecological indicators (Nutritional Mode Index, IMN) and several species richness estimators (Chao 1, Chao 2, Jacknife 1, Jacknife 2, ACE, ICE, Bootstrap and EstimateS 9.1.0). Our results indicate that in surveys in which the taxa richness of the communities is the objective, 20 samples or even more could be needed. However, when the objective of the study is to assess the environmental quality by means of ecological indexes such as the IMN, three samples could be an acceptable benchmark. Our findings, despite being limited by our experiment conditions, can provide methodological guidelines for ecological assessments in Mediterranean rice fields and shallow non-vegetated lagoons. Further research involving multiple study areas and seasonal patterns will help meliorate the accuracy of this protocol and refine sampling efforts in wetlands.

Pesticide use in developing countries increases rapidly. In many regions, we miss knowledge of how frequently pesticides are applied and which active ingredients are used. We present a new cost-efficient and rapid assessment method of recording pesticides diversity in rice-dominated landscapes and present some evidence of the misuse of active ingredients in our study regions. We investigated 17 rice fields in two regions of Northern Vietnam in 2014 and 2015. At each region, we explore the abundance of pesticides used with three methods including (1) the novel approach of collecting pesticide packages close to our target rice fields, (2) observations of farmers spraying pesticides in the surrounding and (3) interviewing local farmers. By collecting pesticide packages, we found 811 packages containing 74 different active ingredients. On average, 19 active ingredients (ranging from four to 40 active ingredients) were applied with an average content of 275.3 g of active ingredients per site. Insecticide packages (39%) were most abundant followed by those of fungicides (31%), herbicides (16%) and other active ingredients (14%). On all sites, active ingredients banned in the European Union were applied by the farmers. Collecting pesticide packages proved to be an efficient and rapidly implemented method to obtain some baseline information about pesticide application (for Northern Vietnam). We suspect that improved agricultural extension services could contribute to good agricultural practices in pest management. Generally, better information and education for local farmers for appropriate use of pesticides seem a necessity.

Pesticide use in developing countries increases rapidly. In many regions, we miss knowledge of how frequently pesticides are applied and which active ingredients are used. We present a new cost-efficient and rapid assessment method of recording pesticides diversity in rice-dominated landscapes and present some evidence of the misuse of active ingredients in our study regions. We investigated 17 rice fields in two regions of Northern Vietnam in 2014 and 2015. At each region, we explore the abundance of pesticides used with three methods including (1) the novel approach of collecting pesticide packages close to our target rice fields, (2) observations of farmers spraying pesticides in the surrounding and (3) interviewing local farmers. By collecting pesticide packages, we found 811 packages containing 74 different active ingredients. On average, 19 active ingredients (ranging from four to 40 active ingredients) were applied with an average content of 275.3 g of active ingredients per site. Insecticide packages (39%) were most abundant followed by those of fungicides (31%), herbicides (16%) and other active ingredients (14%). On all sites, active ingredients banned in the European Union were applied by the farmers. Collecting pesticide packages proved to be an efficient and rapidly implemented method to obtain some baseline information about pesticide application (for Northern Vietnam). We suspect that improved agricultural extension services could contribute to good agricultural practices in pest management. Generally, better information and education for local farmers for appropriate use of pesticides seem a necessity.

Deltas provide many worthy ecosystem services. Yet, delta basins are quite vulnerable, especially in the face of climate change, which can affect the outcome of both agriculture and biodiversity. Moreover, rice paddy cultivation is well known to contribute with strong emissions of greenhouse gases (GHGs), such as methane (CH4). Thus, knowing the atmospheric variability of CH4 in relation to the different stages of the rice culture cycle could help to improve GHGs' mitigation strategies in deltas. The Ebro River Delta, in the northwestern Mediterranean basin, forms part of the largest Spanish river basin and is mainly covered by rice fields. In this study, for the first time, ground level (40 cm a.g.l.) atmospheric CH4 concentrations have been monitored in this area, through twenty-seven car mobile transects, over the course of one year. Seasonal, diurnal and spatial variability of CH4 concentrations were studied to identify its relationship with rice cultivation, meteorological conditions and land-use distribution. With regard to seasonal variability, autumn transects showed the highest mean values for atmospheric CH4 (2.466 ppm) when dead rice straw is mixed with the sediment, and weed growth is prevented. Spring and summer measurements gave the highest mean CH4 values at dawn (1.897e3.544 ppm), whereas autumn and winter produced the mean values after sunset (2.148e2.930 ppm). Spatial differences were accounted for by proximity to urban areas, presence of shallow water storage structures, and distance to seawater., Postprint (author's final draft)

Agricultural development is basically one of the systems development is no less important in supporting the success of the national development. Development of the agricultural sector aims to develop agricultural businesses in rural areas that will spur rural economic activity, create jobs and improve the welfare of society grow upstream, downstream and support in enhancing the competitiveness and added value of agricultural products. The purpose of this study to: (i) large knowing rice farming income in Cemara Labat Village Kapuas Kuala District Kapuas regency, (ii) determine the feasibility of rice farming In Cemara Labat Village Kapuas Kuala District Kapuas regency. Determination of respondent committed intentionally (purposive), Total farmer respondents (sample) taken in this study of 30 rice farmers. The analysis used in this research is revenue analysis and feasibility analysis. The results showed that rice farming income in the village of Cemara Labat Kapuas Kuala District of Rp 10.807.462 Ha-1. Rice farm In Cemara Labat Village Kapuas Kuala District Kapuas regency viable with the value of revenue cost ratio (RCR ) to 2.73, which means that any expenditure of Rp 1.000,- will generate revenue of Rp 2.730,-.

Agricultural development is basically one of the systems development is no less important in supporting the success of the national development. Development of the agricultural sector aims to develop agricultural businesses in rural areas that will spur rural economic activity, create jobs and improve the welfare of society grow upstream, downstream and support in enhancing the competitiveness and added value of agricultural products. The purpose of this study to: (i) large knowing rice farming income in Cemara Labat Village Kapuas Kuala District Kapuas regency, (ii) determine the feasibility of rice farming In Cemara Labat Village Kapuas Kuala District Kapuas regency. Determination of respondent committed intentionally (purposive), Total farmer respondents (sample) taken in this study of 30 rice farmers. The analysis used in this research is revenue analysis and feasibility analysis. The results showed that rice farming income in the village of Cemara Labat Kapuas Kuala District of Rp 10.807.462 Ha-1. Rice farm In Cemara Labat Village Kapuas Kuala District Kapuas regency viable with the value of revenue cost ratio (RCR ) to 2.73, which means that any expenditure of Rp 1.000,- will generate revenue of Rp 2.730,-.

14 species of Draparnaldia were reported from Rice fields of Garwha Allahabad. Of these Draparnaldia iyengarii Tiwari and Pandey, Draparnaldia deskacharyi Yadav, Draparnaldia bori Nizamii, Draparnaldia bory Plumosa and Draparnaldia bisiach Agradh are first time reported from Garwha Allahabad, they constitute new record for the area.

14 species of Draparnaldia were reported from Rice fields of Garwha Allahabad. Of these Draparnaldia iyengarii Tiwari and Pandey, Draparnaldia deskacharyi Yadav, Draparnaldia bori Nizamii, Draparnaldia bory Plumosa and Draparnaldia bisiach Agradh are first time reported from Garwha Allahabad, they constitute new record for the area.

14 species of Draparnaldia were reported from Rice fields of Garwha Allahabad. Of these Draparnaldia iyengarii Tiwari and Pandey, Draparnaldia deskacharyi Yadav, Draparnaldia bori Nizamii, Draparnaldia bory Plumosa and Draparnaldia bisiach Agradh are first time reported from Garwha Allahabad, they constitute new record for the area.

14 species of Draparnaldia were reported from Rice fields of Garwha Allahabad. Of these Draparnaldia iyengarii Tiwari and Pandey, Draparnaldia deskacharyi Yadav, Draparnaldia bori Nizamii, Draparnaldia bory Plumosa and Draparnaldia bisiach Agradh are first time reported from Garwha Allahabad, they constitute new record for the area.

The role of rice fields as feeding habitats for the two main waterfowl herbivores, Eurasian Coot (Fulica atra) and Mallard (Anas platyrhynchos), in the Ebro Delta, a Mediterranean wetland in northeastern Spain, was investigated. Exclusion cages and tethering experiments were deployed within a rice field at the beginning of the growing season (summer 2010) and before harvest (autumn 2010). In summer, waterfowl abundances were low, but cage experiments detected rice field damage by waterfowl grazing through a significant reduction in plant biomass (although consumption was undetectable using tethers). In autumn, waterfowl abundance increased and tethering experiments detected consumption of rice plants with developed seeds, whereas cage experiments did not show grazing effects. Gut content analyses indicate that Mallards are mainly granivorous, feeding mostly on seeds of spiral ditch grass (Ruppia cirrhosa) and rice (Oryza sativa), while Eurasian Coots are herbivorous, feeding mainly on macrophyte leaves. However, stable isotope analyses and mixing model results showed that in the long term both species seem to acquire most of their dietary needs from rice plants and sago pondweed (Potamogeton pectinatus). Dietary analyses confirm the importance of rice in both species' diets but also suggest that waterfowl may undergo seasonal dietary variations. These are mostly influenced by changes in the availability of food resources in the area rather than by their nutritional quality. This study confirms the ecological importance of rice fields as a complementary feeding habitat for waterfowl during the growing season in Mediterranean areas. It also highlights the importance of including these habitats in wetland management for waterfowl conservation.

The role of rice fields as feeding habitats for the two main waterfowl herbivores, Eurasian Coot (Fulica atra) and Mallard (Anas platyrhynchos), in the Ebro Delta, a Mediterranean wetland in northeastern Spain, was investigated. Exclusion cages and tethering experiments were deployed within a rice field at the beginning of the growing season (summer 2010) and before harvest (autumn 2010). In summer, waterfowl abundances were low, but cage experiments detected rice field damage by waterfowl grazing through a significant reduction in plant biomass (although consumption was undetectable using tethers). In autumn, waterfowl abundance increased and tethering experiments detected consumption of rice plants with developed seeds, whereas cage experiments did not show grazing effects. Gut content analyses indicate that Mallards are mainly granivorous, feeding mostly on seeds of spiral ditch grass (Ruppia cirrhosa) and rice (Oryza sativa), while Eurasian Coots are herbivorous, feeding mainly on macrophyte leaves. However, stable isotope analyses and mixing model results showed that in the long term both species seem to acquire most of their dietary needs from rice plants and sago pondweed (Potamogeton pectinatus). Dietary analyses confirm the importance of rice in both species' diets but also suggest that waterfowl may undergo seasonal dietary variations. These are mostly influenced by changes in the availability of food resources in the area rather than by their nutritional quality. This study confirms the ecological importance of rice fields as a complementary feeding habitat for waterfowl during the growing season in Mediterranean areas. It also highlights the importance of including these habitats in wetland management for waterfowl conservation.

Within the frame work of the Sino-Dutch Pesticide Environment Risk Assessment Project (PERAP) and as part of the Chinese environmental ris assessment procedures models and scenarions were developed to estimate concentrations of Plant Protection Product (PPP) leaching to the groundwater and to estimate PPP concentrations in Chinese small surface waters. Protection goals considering groundwater and surface water were defined in detail. Realistic worst-case groundwater scenario's and surface water scenarios were defined to be used in respectively a Tier 1 leaching assessment of PPP a Tier 1 assesment of the risks of PPP to aquatic ecosystems in China. Data on soil, weather, crops, irrigation and Agricultural practices were gathered for both scenario definitions. Existing models PEARL and TOXSWA were modified and parameterised for the scenarions defined.

Over the last decades the Continental European population of black-tailed godwits, Limosa limosa limosa, has shown steep declines as a consequence of agricultural intensification on the breeding grounds. Although numbers have also declined in their traditional wintering areas in West-Africa, in the Doñana wetlands of southwestern Spain high nonbreeding numbers have persisted. Here we provide a long-term (35. year, 1977-2011) analysis of godwit numbers in Doñana. In fact, from the mid 1990s there has been a steep increase in numbers so that the fraction of godwits along this flyway that winters in Doñana increased from 4% in the late 1980s to 23% in 2011. These changes were not correlated with climatic conditions in Spain, nor in Sahel, but they were associated with changes in habitat availability - mainly an increase in man-made artificial wetlands. Commercial fish-farms and rice fields provide alternative habitats to the original seasonal marshlands for daytime roosting (mainly in the fish ponds) or nocturnal foraging (probably rice fields in addition to fish ponds). For migrating waterbirds, degradations of natural wetlands can thus be compensated by man-made alternative habitats. As the availability especially of such man-made areas is highly sensitive to short-term political/economic driven decision-making, they should be given greater consideration in global conservation plans. © 2014 Elsevier Ltd.

Greater Angkor was the capital of the Khmer Empire from the ninth to the fourteenth centuries a.d. The rulers of Angkor left behind magnificent temples, along with extensive, centrally planned landscapes and massive urban complexes. However, the landscape of Greater Angkor also represents a decentralized planning tradition. This article addresses the different scales of economic landscapes at Greater Angkor: from massive ricefield superstructures watered by artificial irrigation, to smaller patches of fields organized around local temples and ponds. Contrary to widely accepted views, the design of extensive cultural landscapes does not require the presence of an elite controlling authority, or the guidance of a commonly conceived plan. Within Greater Angkor, the design of extensive landscapes often occurred at the local level, most likely involving local traditions rather than abstract, centrally approved plans. The relationship between centralized and decentralized planning traditions is investigated using a topographic classification of the landscape based on extensive mapping from remote sensed imagery from 2007–2010. Covering 1000 km2 of rice fields, and including 22,000 km of rice-field bunds, the topographic classification of the rice-field systems reveals two very different ways of building. These two systems are best described as coaxial systems and cardinal systems: both suggest dramatically different development models and socioeconomic frameworks. The two different, and extensive, development processes had a lasting physical impact on the resulting landscapes, and are still actively used today. This article discusses the evidence for both central and local plans as well as more complicated examples, where both central and local plans seem to have influenced the design of landscapes. Illustrated examples of centrally planned landscapes and local approaches to planning landscapes demonstrate this premise.

[EN] Rice fields contribute substantially to global warming of the atmosphere through emission of methane (CH4). This article reviews the state of the art of factors affecting CH4 emissions in rice fields, focusing on soil organic matter content and water management practices. A quantitative relationship between these factors was established through a meta-analysis based on a literature survey. This relationship can be useful to update emission factors used to estimate CH4 in the National Emission Inventories. Methane emissions in rice fields can be as much as 90% higher in continuously flooded rice fields compared with other water management practices, independent from straw addition. Water management systems that involve absence of flooding in total or for part of the growing period such as midseason drainages, intermittent flooding, and percolation control, can reduce CH4 emissions substantially. Moreover, CH4 emissions increase with the amount of straw added up to 7.7 t/ha for continuously flooded soils and up to 5.1 t/ha for other water regimes. Above these levels, no further increase is produced with further addition of straw. With regard to rice straw management mitigation strategies, recommended practices are composting rice straw, straw burning under controlled conditions, recollecting rice straw for biochar production, generation of energy, to be used as a substrate, or to obtain other byproducts with added value. This review improves the understanding of the relationship between straw application rate, water regimes, and CH4 emissions from rice fields to date. This relationship can help to select the most appropriate management practices to improve current mitigation strategies to reduce atmospheric CH4. © 2012 Mary Ann Liebert, Inc.

The Panel considers the Spanish pest risk analysis (PRA) to be clear and to provide appropriate supporting evidence. However, (i) the environmental impact assessment is incomplete and (ii) the estimates for the potentially endangered area are too limited. The Panel points out that large areas of the European Union have climatic conditions, that are very similar to those of the areas of native distribution of Pomacea spp. snails, and suitable host plants are available. The Panel agrees with the Spanish PRA on the following points with regard to the risk assessment area: (i) the potential consequences of the organism for rice crops are major; (ii) the probability for establishment of the organism is very likely and (iii) the probability of spread is estimated as likely. The Panel disagrees with the Spanish PRA on the following points and considers (i) the effects on the environment to be massive under suitable environmental conditions in the PRA area and (ii) the probability of entry of the organism to be high. Regarding risk reduction options the Panel agrees with the Spanish PRA that no single risk reduction method is sufficient to halt the introduction and spread of Pomacea spp. snails in the PRA area. However, a legislative ban on import of Pomacea spp. is the only risk reduction option identified that can reduce the probability of entry. The many other risk reduction options listed will help to reduce the probability of spread within the PRA area. The Panel considers that the risk reduction options should target the canaliculata complex, as Pomacea insularum and P. canaliculata, as well as other species from the complex, are almost indistinguishable. This is of particular importance for risk reduction options addressing both breeding and trade of the organism.

A knowledge of the foraging strategies of marine predators is essential to understand the intrinsic factors controlling their distribution, abundance and their ecological function within the marine ecosystem. Here, we investigated for the first time the foraging movements and activity patterns of Audouin’s gull Larus audouinii by using satellite-tracking data from eight breeding adults in the main colony of the species worldwide (Ebro Delta, NW Mediterranean). Tagged gulls foraged in the marine area close to the breeding colony (62% of foraging locations) and in the terrestrial area of the Ebro Delta (mainly rice fields; 38% of foraging locations). The foraging activity patterns changed significantly throughout the day; lower from dusk through the first half of the night (19-1 h; 32% of active locations) and higher during the rest of the day (1–19 h; 75.5 ± 4.3% of active locations). These results confirm the foraging plasticity of this seabird and, based on previous information about the dietary habits of this species, we hypothesize how its time-dependent activity patterns and habitat use could be associated with variations in the availability of marine food resources (e.g. diel vertical migrations of pelagic fish) and the exploitation of terrestrial resources (e.g. American crayfish Procambarus clarkii)

Background: Malaria mosquitoes spend a considerable part of their life in the aquatic stage, rendering them vulnerable to interventions directed to aquatic habitats. Recent successes of mosquito larval control have been reported using environmental and biological tools. Here, we report the effects of shading by plants and biological control agents on the development and survival of anopheline and culicine mosquito larvae in man-made natural habitats in western Kenya. Trials consisted of environmental manipulation using locally available plants, the introduction of predatory fish and/or the use of Bacillus thuringiensis var. israelensis (Bti) in various combinations. Results: Man-made habitats provided with shade from different crop species produced significantly fewer larvae than those without shade especially for the malaria vector Anopheles gambiae. Larval control of the African malaria mosquito An. gambiae and other mosquito species was effective in habitats where both predatory fish and Bti were applied, than where the two biological control agents were administered independently. Conclusion: We conclude that integration of environmental management techniques using shade-providing plants and predatory fish and/or Bti are effective and sustainable tools for the control of malaria and other mosquito-borne disease vectors.

The aim of this study was to assess the ecotoxicological effects of water coming from untreated organic and conventional rice field production areas in the Ebro Delta (Catalonia, Spain) treated with the herbicides oxadiazon, benzofenap, clomazone and bensulfuron-methyl and the fungicides carbendazim, tricyclazole and flusilazole. Irrigation and drainage channels of the study locations were also included to account for potential toxic effects of water coming in and out of the studied rice fields. Toxicity tests included four species (Pseudokirchneriella subcapitata, Desmodesmus subcapitatus, Chlorella vulgaris and Daphnia magna), three endpoints (microalgae growth, D. magna mortality and feeding rates), and two trophic levels: primary producers (microalgae) and grazers (D. magna). Pesticides in water were analyzed by solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS). Negative effects on algae growth and D. magna feeding rates were detected mainly after application of herbicides and fungicides, respectively, in the conventional rice field. Results indicated that most of the observed negative effects in microalgae and D. magna were explained by the presence of herbicides and fungicides. The above mentioned analyses also denoted an inverse relationship between phytoplankton biomass measured as chlorophyll a and herbicides. In summary, this study indicates that in real field situations low to moderate levels of herbicides and fungicides have negative impacts to planktonic organisms and these effects seem to be short-lived.

The aim of this study was to assess the ecotoxicological effects of water coming from untreated organic and conventional rice field production areas in the Ebro Delta (Catalonia, Spain) treated with the herbicides oxadiazon, benzofenap, clomazone and bensulfuron-methyl and the fungicides carbendazim, tricyclazole and flusilazole. Irrigation and drainage channels of the study locations were also included to account for potential toxic effects of water coming in and out of the studied rice fields. Toxicity tests included four species (Pseudokirchneriella subcapitata, Desmodesmus subcapitatus, Chlorella vulgaris and Daphnia magna), three endpoints (microalgae growth, D. magna mortality and feeding rates), and two trophic levels: primary producers (microalgae) and grazers (D. magna). Pesticides in water were analyzed by solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS). Negative effects on algae growth and D. magna feeding rates were detected mainly after application of herbicides and fungicides, respectively, in the conventional rice field. Results indicated that most of the observed negative effects in microalgae and D. magna were explained by the presence of herbicides and fungicides. The above mentioned analyses also denoted an inverse relationship between phytoplankton biomass measured as chlorophyll a and herbicides. In summary, this study indicates that in real field situations low to moderate levels of herbicides and fungicides have negative impacts to planktonic organisms and these effects seem to be short-lived.

Pseudomonas sp. strain S3 was isolated from Paddy (rice) field agricultural area. This organism, which can utilize a halogenated compound of D,L-2-Chloropropionic acid as sole carbon and energy source, catalyses the hydrolytic dehalogenation of both D- and L- isomers of 2-Chloropropionic acid. Identification of Pseudomonas sp. S3 is still ambiguous due to the lack of basic studies, especially their molecular genetic information. In this study, the amplified 16S rRNA gene sequence of Pseudomonas sp. S3 (Accession No. FJ968758) was compared to other nine selected gene sequences from the same group of Pseudomonas sp. and/or dehalogenase producing bacteria using in silico method. Their phylogenetic relationships were then determined. The results were analysed using MEGA4 software to ascertain its evolutionary distance by reconstructing a phylogenetic tree of these organisms. The evolutionary history and bootstrap consensus tree were inferred using the Neighbour-Joining method from 500 replicates. The tree is drawn to scale, with branch lengths (next to the branches) in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the p-distance method and were in the units of the number of base substitutions per site. Based on this analysis, Pseudomonas sp. S3 16S rRNA gene was closely related to the Pseudomonas chlororaphis with genetic distance 0.170 base substitutions per site. S3 gene was also compared among known dehalogenase producing bacteria 16S rRNA genes. Results suggested that S3 was closely related to the Pseudomonas sp. R1 with a genetic distance 0.040 base substitutions per site. From present study, evolutionary relationships of 16S rRNA gene of Pseudomonas sp. S3 were elegantly illustrated by phylograms, comparable to a pedigree showing which microorganisms are most closely related.

In the Ebro River basin, point and diffuse pollution of heavy metals stems mainly from industry and agriculture. Bioaccumulation patterns were examined under different pollution sources (point and diffuse) using levels of heavy metals (As, Cd, Cr, Cu, Hg, Pb and Zn) in abdominal muscle tissue of Procambarus clarkii. P. clarkii captured under point source effects presented the highest concentrations of Hg, Pb and As; and were related with distance to the source of industrial waste sediments. Mean Hg levels in crayfish exposed to point sources of metals significantly exceeded legal allowed values established by the European Union legislation. In the Ebro Delta, high levels of As, Cr, Cu and Zn were associated with traditional agriculture activity (diffuse pollution) as well. These results demonstrate the potential of P. clarkii to bioaccumulate heavy metals from both point and diffuse sources and hence potentially transfer these metals to higher trophic levels.

A bacterial strain tentatively identified as Pseudomonas sp. R1 was isolated from a paddy (rice) field that could degrade monochloroacetic acid (MCA) for concentrations ranging from 5 to 40 mM. Quantitative agreement between the amount of MCA introduced and chloride released was also found. MCA dehalogenase activity in this strain was found to be inducible. Cell-free extracts displayed dehalogenating activity with specific halogenated organic compound with no activity on dichloropropionic acid or monochloropropionic acid. The estimated Km values for MCA was 0.14 mM. The optimal pH range for MCA dehalogenase activity (between pH 6.5 and 8.0), whereas the thermal stability profile stable up to 50 °C. The results of our current study demonstrated the potential use of Pseudomonas sp. R1 as suitable biological agent for biodegradation of MCA in contaminated agricultural area.

PROBLEM: Irrigated agriculture exposes rural people to health risks associated with vector-borne diseases and pesticides used in agriculture and for public health protection. Most developing countries lack collaboration between the agricultural and health sectors to jointly address these problems. APPROACH: We present an evaluation of a project that uses the "farmer field school" method to teach farmers how to manage vector-borne diseases and how to improve rice yields. Teaching farmers about these two concepts together is known as "integrated pest and vector management". LOCAL SETTING: An intersectoral project targeting rice irrigation systems in Sri Lanka. RELEVANT CHANGES: Project partners developed a new curriculum for the field school that included a component on vector-borne diseases. Rice farmers in intervention villages who graduated from the field school took vector-control actions as well as improving environmental sanitation and their personal protection measures against disease transmission. They also reduced their use of agricultural pesticides, especially insecticides. LESSONS LEARNED: The intervention motivated and enabled rural people to take part in vector-management activities and to reduce several environmental health risks. There is scope for expanding the curriculum to include information on the harmful effects of pesticides on human health and to address other public health concerns. Benefits of this approach for community-based health programmes have not yet been optimally assessed. Also, the institutional basis of the integrated management approach needs to be broadened so that people from a wider range of organizations take part. A monitoring and evaluation system needs to be established to measure the performance of integrated management initiatives.

Malaria has strong linkages with agriculture, and farmers in malarious regions have a central position in creating or controlling the conditions that favour disease transmission. An interdisciplinary and integrated approach is needed to involve farmers and more than one sector in control efforts. It is suggested that malaria control can benefit from a complementary intervention in rural development, the Farmer Field School (FFS) on Integrated Pest Management (IPM). This is a form of education that uses experiential learning methods to build farmers' expertise, and has proven farm-level and empowerment effects. The benefits of incorporating malaria control into the IPM curriculum are discussed. An example of a combined health-agriculture curriculum, labeled Integrated Pest and Vector Management (IPVM), developed in Sri Lanka is presented. Institutional ownership and support for IPVM could potentially be spread over several public sectors requiring a process for institutional learning and reform

Background - Although the effects of rainfall on the population dynamics of the malaria vector Anopheles gambiae have been studied in great detail, the effects of dry periods on its survival remain less clear. Methods - The effects of drying conditions were simulated by creating desiccated habitats, which consisted of trays filled with damp soil. Experiments were performed in these trays to (i) test the ability of An. gambiae sensu stricto eggs to hatch on damp soil and for larvae to reach an artificial breeding site at different distances of the site of hatching and (ii) to record survival of the four larval stages of An. gambiae s.s. when placed on damp soil. Results - Eggs of An. gambiae s.s. hatched on damp soil and emerging larvae were capable of covering a distance of up to 10 cm to reach surface water enabling further development. However, proportions of larvae reaching the site decreased rapidly with increasing distance. First, second and third-instar larvae survived on damp soil for an estimated period of 64, 65 and 69 hrs, respectively. Fourth-instar larvae survived significantly longer and we estimated that the maximum survival time was 113 hrs. Conclusion - Short-term survival of aquatic stages of An. gambiae on wet soil may be important and adaptive when considering the transient nature of breeding sites of this species in sub-Saharan Africa. In addition, the results suggest that, for larval vector control methods to be effective, habitats should remain drained for at least 5 days to kill all larvae (e.g. in rice fields) and habitats that recently dried up should be treated as well, if larvicidal agents are applied

The primary objective of this study was to obtain information on the environmental characteristics of rice fields in the United States and the effect of these characteristics on ground mobility for comparison with similar characteristics of rice fields in Southeast Asia as data from the latter become available. Twenty-two study sites were located in rice fields in a variety of soil types and under various cultural practices in Arkansas and Louisiana. Fifteen of the 22 sites were selected for data collection several times during a one-year period (March 1963-March 1964) to determine the seasonal variations in soil moisture, strength, vegetation characteristics, and hydrologic geometry characteristics. Cultural practices and data from the nearest weather stations also were recorded. Profiles and spacing of surface and hydrologic geometry features were measured. General conclusions were: (a) for most U.S. rice fields tested a good correlation exists between soil strength (in terms of rating cone index) and soilmoisture content; (b) estimates of soil strength of rice fields can be made by employing the WES soil moisture -strength prediction method; (c) surface geometry features (dikes) found in U.S. rice fields would not be a significant deterrent to ground vehicles. (Author)

The over-all purpose of this study is to determine seasonal characteristics of rice fields, pertinent to military operations, in several locations in the United States. The specific objectives of the field trips reported herein were to: (a) Collect data during the peak of the wet season in selected areas of the Mississippi Valley rice lands to (1) determine maximum moisture condictions produced by natural wetting and (2) delineate the trafficability characteristics of the soils. (b) Measure vegetation and terrain geometry of rice-field surfaces. (c) Obtain information on the cultural practices used in the U. S. rice lands. (d) Determine what information is presently available on rice lands, such as soil maps, weather records, aerial photographs, cultural practices.