Rice-based Ecosystems Research Articles

Adoption of Pest Management Practice Wise Green Technologies Utilization Behaviour of Trichy and Madurai District Farmers in Rice-based Ecosystem

The current study was carried out in Madurai and Trichy districts of Tamil Nadu. Two blocks from each district were chosen. For this study, a total sample size of 240 people was used. It was seen that 52.08 per cent of the respondents had fully adopted the destruction of stubbles after harvest in which 56.67 per cent of Trichy district farmers and 47.50 per cent of Madurai district farmers had fully adopted the above practice in order to avoid yellow stem borer. More than half (51.67%) of the farmers had adopted placing of dry fish in the field in which 56.67 per cent of Trichy district farmers and 46.66 per cent of Madurai district farmers had fully adopted this practice. It was observed that 50.00 per cent of Trichy district respondents and 27.50 per cent of Madurai district respondents had partially adopted the practice of dipping the seedlings with chloropyriphos to avoid the attack of termites.

Adoption of Agronomic Practice Wise Green Technologies Utilization Behaviour of Trichy and Madurai District Farmers in Rice-Based Ecosystem

The current study was carried out in Madurai and Trichy districts of Tamil Nadu. Two blocks from each district were chosen. For this study, a total sample size of 240 people was used. More than half (60.00%) of the farmers had fully adopted the seed treatment practices in which 62.50 per cent of Trichy district farmers had fully adopted and more than half (57.50%) of Madurai district farmers had fully adopted the above practices. More than three-fourths (83.33%) of the farmers had fully adopted in which 86.66 per cent followed by 80.00 per cent of Trichy and Madurai district farmers had fully adopted the application of farm yard manure respectively. Exactly half of the Trichy district respondents (50.00%) had fully adopted summer ploughing followed by 52.50 per cent of Madurai farmers.

Sublethal effects of chlorantraniliprole on growth, biochemical and molecular parameters in two chironomids, Chironomus kiiensis and Chironomus javanus

Pesticide residues have serious environmental impacts on rice-based ecosystems. In rice fields, Chironomus kiiensis and Chironomus javanus provide alternative food sources to predatory natural enemies of rice insect pests, especially when pests are low. Chlorantraniliprole is a substitute for older classes of insecticides and has been used extensively to control rice pests. To determine the ecological risks of chlorantraniliprole in rice fields, we evaluated its toxic effects on certain growth, biochemical and molecular parameters in these two chironomids. The toxicity tests were performed by exposing third-instar larvae to a range of concentrations of chlorantraniliprole. LC50 values at 24 h, 48 h, and 10 days showed that chlorantraniliprole was more toxic to C. javanus than to C. kiiensis. Chlorantraniliprole significantly prolonged the larval growth duration, inhibited pupation and emergence, and decreased egg numbers of C. kiiensis and C. javanus at sublethal dosages (LC10 = 1.50 mg/L and LC25 = 3.00 mg/L for C. kiiensis; LC10 = 0.25 mg/L and LC25 = 0.50 mg/L for C. javanus). Sublethal exposure to chlorantraniliprole significantly decreased the activity of the detoxification enzymes carboxylesterase (CarE) and glutathione S-transferases (GSTs) in both C. kiiensis and C. javanus. Sublethal exposure to chlorantraniliprole also markedly inhibited the activity of the antioxidant enzyme peroxidase (POD) in C. kiiensis and POD and catalase (CAT) in C. javanus. Expression levels of 12 genes revealed that detoxification and antioxidant abilities were affected by sublethal exposures to chlorantraniliprole. There were significant changes in the expression levels of seven genes (CarE6, CYP9AU1, CYP6FV2, GSTo1, GSTs1, GSTd2, and POD) in C. kiiensis and ten genes (CarE6, CYP9AU1, CYP6FV2, GSTo1, GSTs1, GSTd2, GSTu1, GSTu2, CAT, and POD) in C. javanus. These results provide a comprehensive overview of the differences in chlorantraniliprole toxicity to chironomids, indicating that C. javanus is more susceptible and suitable as an indicator for ecological risk assessment in rice ecosystems.

Achievement of Target Yield by Using Required Quantitative Fertilizers in Rice Crop Cultivation by Using Optimum Solutions

Studies of soil-based tests pertaining to different crops in Vindhyan alluvial plains from 2001 to 2004 show effect of production on specific rice crop by IR-36 testing leveraging on soil stoichiometric testing and recommended balanced fertilizers and organic matter amelioration by application for the niche area of impact to targeted yield of rice crop. Findings reinforce that soil micro-flora and micro-organisms accelerate aeration, porosity, drainage and optimum crumby structures, resulting in nascent fertility and support to crop plant for profuse and vigorous growth through optimum soil texture under different agro-climatological divisions in specificity. Primary and secondary data are tabulated after administration of research questionnaire, structure, queue, flow and research objectives, first hand data fulfilment through field notes and experimental block designs under study in rice-based ecosystem of control and treatment blocks. The study of nutrients requirement for specific accelerated productivity of rice crop by applying control and treatment with particular fertilisers which is structured in the mathematical model of [CF (%)] and [CS (%)] gradient. Further data in relation to studies of nutrient dose recommended model development through incursion into stoichiometric trends, analysis, models, algorithms, principles, procedures and quantisation. Regression based studies support the experimental design blocks. Studies by experimental design of blocks replication and finding of experimentations led to outcome of best efficacy and efficient recommended fertiliser dose to enrich, replenish the gap of inadequate fertilizers to the paddy crop to meet our targeted yield of paddy crops. Analytical trends and comparison experimentation sheet led to the effort for how much fertilizer is actually required for crop growth by applying mathematical quantization and qualitative. Under experimental controls and originality of this innovative findings, this research supports systems approach for simplicity, spirituality and sustainability.

Changes in rural household characteristics and their implications on agricultural income in wetland rice ecosystems

Agricultural development has impacted changes in rural economic structure, as reflected by rural economic indicators.. The research question is how the direction of the changes is and the implications for rural household agricultural income. This paper aims to analyses household characteristics changes in the rice-based ecosystems and their implication on household agricultural income. The study used micro-panel data of the National Farmers Panel (in 2010 and 2016) from the Indonesian Centre for Agro Socio-Economic and Policy Studies. The survey was conducted in 14 villages of five rice production centers provinces in Java and Outside Java. The number of respondents is 559 households. Data was analyzed statistically descriptive by calculating the average, minimum-maximum numbers, and participation rate. Generalized Linear Models method was employed to determine the factors affecting household agricultural income. The results showed that agricultural land occupation tends to decrease. The number of older workers tends to increase. The increase of workforce older than 65 years is more significant in Java than Outside Java. The workforce level of education remains predominantly in elementary school. Although nominal total income increased significantly, real income increase sluggishly. Household agricultural income is still dominant but declining. The farmland managed, age and level of education of the household member, number of the household member, and cropping intensity affect household agricultural income significantly. To increase the household agricultural income by increasing the production capacity of farmers’ households through increasing land occupation, improving human resources skills, and facilitating innovative technology that can increase farming efficiency and productivity.

Significant bioaccumulation and biotransformation of methyl mercury by organisms in rice paddy ecosystems: A potential health risk to humans.

Rice has been confirmed as one of the principal intake pathways for methylmercury (MeHg) in human, however, the impact of edible organisms, such as snails, loaches and eels, living in the rice-based ecosystem to the overall MeHg intake has been overlooked. Here, we conducted a cross-sectional ecological study, and the results showed that bioaccumulation of MeHg in these edible organisms was significantly higher than in paddy soils and rice roots (p<0.001), even though rice roots and grains have significantly higher total Hg (THg) (p<0.001). The MeHg/THg ratios were consistently and significantly higher in those edible organisms than in rice grains, suggesting a potential elevated MeHg exposure risk through consumption. Based on results of bioaccumulation factors (BAFs) for MeHg, it was clear that MeHg was bioaccumulated and biotransformed from paddy soils to earthworms and then to eels, as well as from paddy soils to snails and then to eels and loaches, potentially indicating that the consumption of eels and loaches was absolutely pernicious to people regularly feeding on them. Overall, MeHg was biomagnified along the food chain of the paddy ecosystem from soil to the organisms, and it was of potential higher risks for local residents to eat them, especially eels and loaches. Therefore, it is intensely indispensable for people fond of such diets to attenuate their consumption of rice, eels and loaches, thus mitigating their MeHg exposure risks.

Mercury flow through an Asian rice-based food web

Mercury (Hg) is a globally-distributed pollutant, toxic to humans and animals. Emissions are particularly high in Asia, and the source of exposure for humans there may also be different from other regions, including rice as well as fish consumption, particularly in contaminated areas. Yet the threats Asian wildlife face in rice-based ecosystems are as yet unclear. We sought to understand how Hg flows through rice-based food webs in historic mining and non-mining regions of Guizhou, China. We measured total Hg (THg) and methylmercury (MeHg) in soil, rice, 38 animal species (27 for MeHg) spanning multiple trophic levels, and examined the relationship between stable isotopes and Hg concentrations. Our results confirm biomagnification of THg/MeHg, with a high trophic magnification slope. Invertivorous songbirds had concentrations of THg in their feathers that were 15x and 3x the concentration reported to significantly impair reproduction, at mining and non-mining sites, respectively. High concentrations in specialist rice consumers and in granivorous birds, the later as high as in piscivorous birds, suggest rice is a primary source of exposure. Spiders had the highest THg concentrations among invertebrates and may represent a vector through which Hg is passed to vertebrates, especially songbirds. Our findings suggest there could be significant population level health effects and consequent biodiversity loss in sensitive ecosystems, like agricultural wetlands, across Asia, and invertivorous songbirds would be good subjects for further studies investigating this possibility.

Host status of rotation crops in Asian rice-based cropping systems to the rice root-knot nematode Meloidogyne graminicola

Rotation with nonhost crops is an important practice used for root-knot nematode (RKN) management. Screenhouse experiments were conducted to evaluate the response infection of 27 cultivars belonging to 14 crops (blackgram, cabbage, cauliflower, chickpea, cowpea, garlic, ginger, greengram, groundnut, maize, potato, sesame, soybean, sunflower), which are grown in rotation with rice in lowland and upland rice-based ecosystems, to the RKN Meloidogyne graminicola. Root galling indices observed on all crop rotation cultivars were significantly lower compared with the rice cv. Thihtatyin, used as positive control. Differences in host response to M. graminicola infection were observed between cultivars. All 27 cultivars were poor or non-hosts of M. graminicola, except cv. Yezin 4 of chickpea considered as good host. No significant differences in plant growth were observed between non-inoculated and inoculated plants of all plant/species cultivars, with the exception of a reduction in root length in the chickpea cv. Yezin 4 (good host) and the garlic cv. Shan (poor host). Rotation crops identified as poor or non-hosts of M. graminicola could be useful in the management of RKN in rice-based cropping systems.

Earthworm bioturbation stabilizes carbon in non-flooded paddy soil at the risk of increasing methane emissions under wet soil conditions

Studies on earthworms in rice-based ecosystems tend to focus on some pest species, while the potential of these important soil engineers for beneficially affecting carbon storage and cycling is widely ignored. We carried out a microcosm experiment to quantify the impact of the tropical earthworm Pheretima sp. on the C turnover in paddy soils under different conditions of water saturation and N fertilization. The soil was sampled at the lowland farm of the International Rice Research Institute (Philippines). In the absence of earthworms, soil respiration showed a distinct hump-shaped maximum at intermediate levels of water saturation (4-fold higher than in hand-dry soil) and increased 1.5-fold with increasing amounts of N fertilization. Amounts of CH4 emitted, in contrast, were small at low to moderate soil humidity and became very high under conditions of water saturation (80-fold higher than hand-dry soil). No response to nitrogen addition was observed. Earthworms suppressed both the respiration maximum at intermediate saturation levels (by a factor of 1.4) and the stimulating impact of N fertilization (1.7-fold at maximum fertilizer level). On the other hand, earthworms strongly increased CH4 release under conditions of high water saturation (3-fold). No consistent response of the soil microflora (bacterial abundance, soil enzymes) to earthworm activity could be established. Our findings suggest that the stabilization of soil organic C via earthworm bioturbation is confined to the range of soil humidity that allows high activity of Pheretima sp. Under conditions of intensive agriculture, the stabilizing effect of the worms may even be augmented by the fact that they offset the positive effect of N fertilization on microbial respiration. Earthworms may thus play a vital role in reducing the CO2 flush from paddy soils after the conversion to non-flooded crops such as aerobic rice or maize. Acceleration of methane emission in very humid soils nevertheless points to a certain risk that is associated with increasing earthworm abundance in production systems that are still exposed to temporary flooding during the wet season.

Tillage effects on soil nitrification and the dynamic changes in nitrifying microorganisms in a subtropical rice-based ecosystem: A long-term field study

The dynamics of N mineralization and nitrification may be altered by tillage, which ultimately affects crop growth and yield. This study investigated effects of tillage on soil nitrogen dynamics in a subtropical rice (Oryza sativa L.) soil (Hydragric Anthrosols, WRB classification) under combination ridge with no-tillage (RNT) and conventional tillage (CT) for 22 years in Chongqing, China. Soil mineralization, nitrification and changes in abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA) were investigated to test the hypothesis that RNT decreases nitrification in the rice-based ecosystem. Soil mineralization and nitrification rates decreased after 22 years of RNT compared with CT. Soil pH decreased about 0.5 units after 22 years of RNT, and this difference may be responsible for the decrease of N mineralization and nitrification rates observed under RNT. The nitrification process was best fitted by a first-order kinetic model for both CT and RNT. While the nitrification rate was significantly lower for RNT (2.96mgNkg−1day−1) than CT (3.40mgNkg−1day−1), AOB and AOA amoA gene copies were significantly higher for RNT than CT. This suggested that the functional expression (i.e., nitrification) may not be closely related to numbers of microorganisms that have the ability to nitrify. The AOA dominated in abundance over the AOB for both CT and RNT paddy soils, with AOA to AOB ratios ranging from 13 to 52, and the AOA abundance showed similar changes with AOB, suggesting that AOA may also play an important role in soil nitrification. Results implied that RNT may increase soil N retention by keeping N longer in the NH4+ state, thus decreasing the potential for N loss from leaching.

Biodiversity and Nutrition in Rice-Based Ecosystems; the Case of Lao PDR

This paper presents results from a year-long household survey in which the aquatic resource collection and consumption activities of 240 households across Lao PDR were studied to assess the diversity of species used, their role in household food security and the overall importance of ricefield habitats in this respect. Results show that aquatic biodiversity, under threat in rice-based ecosystems, plays a larger role in household consumption than previous estimates. More than 90 % of these resources are collected by households themselves and the greatest quantities from ricefield habitats. This seasonal aquatic environment is therefore the principal habitat from which households acquire aquatic animals, both to eat fresh and to process and store for use during nutritionally vulnerable times of year. The importance of these habitats therefore goes far beyond their use for rice production and this multi-functionality needs to be understood and addressed in agricultural, conservation and food security policy.

Seasonal variability of microbial biomass associated with aggregates in a rice-based ecosystem

Temporal variability of soil microbial biomass shows contradictory trends for different ecosystems. Since soils are comprised of many sizes of aggregates and soil particles, we hypothesized that the microbial biomass response to seasonal variation is more sensitive at the aggregate scale than for whole soil. Tillage impacts on seasonal variation of microbial biomass were determined for a hydargric Anthrosol in China from 2008 to 2009. No significant seasonal changes occurred for soil total organic C (TOC), but microbial biomass C (MBC) exhibited distinct seasonal variation. However, seasonal variation patterns of MBC associated with aggregates coincided with patterns for whole soil, regardless of tillage regimes.The MBC in whole soil was significantly higher in spring (272 mg kg−1) than autumn (186 mg kg−1) and winter (165 mg kg−1) under CT (conventional tillage), while MBC was higher in spring and autumn than winter and summer for RNT (ridge with no-till). Microorganisms associated with different sizes of aggregates responded similarly to environmental changes, but the degree of response for different sizes of aggregates varied. The CV (coefficient of variation) for seasonal change was lowest for macroaggregates, while the highest CVs occurred for the silt + clay fraction. The results indicated that soil microorganisms associated with macroaggregates were more stable than with silt + clay fractions to resist seasonal changes in climate and soil properties, and therefore more likely to play a role in enhancing nutrient conservation in the soil. Seasonal variation patterns of microbial biomass associated with aggregates coincided with patterns for whole soil, suggesting that microorganisms associated with different size fractions of aggregates respond to macro- and micro-environmental changes in a similar way.

Polycultural manipulation for better regulation of planthopper populations in irrigated rice-based ecosystems

The frequent outbreaks of rice planthoppers, especially brown planthopper Nilaparvata lugens (Stål), in the last ten years in China and other Asian countries have caused serious rice (Oryza sativa L.) yield losses. The key problem is possibly due to biodiversity loss in rice ecosystems. We examined the potential of intercrops of soybean (Glycine max L.) and corn (Zea mays L.), both of which are more profitable than rice and mostly planted in levees, to diversify rice ecosystems and enhance insect pest management. We studied the impacts of such intercrops on planthopper populations and their natural enemies. The results showed significantly lower numbers of rice planthoppers in rice fields with intercrops of corn than in rice monocultures and rice fields with intercrops of soybean. Rice fields with corn intercrops had 26–48% fewer planthoppers than rice monoculture. Rice fields with soybean intercrops had lower rice planthopper abundance compared to rice monoculture in 2008 but higher in 2009. However, neither parasitoid nor predator numbers were significantly affected by intercropping. There were no significant differences in directional movements of planthoppers or natural enemies between crop subplots in the different cropping systems. Moreover, movement of planthoppers was very limited. Our study indicated that soybean and corn intercrops do not greatly enhance the ability of natural enemies to suppress planthoppers. However, rice fields with intercrops of corn had lower abundance of planthoppers and this strategy may be useful as part of an integrated pest management strategy for the sustainable rice production.

Can polycultural manipulation effectively control rice planthoppers in rice-based ecosystems?

Rice planthoppers (mainly Nilaparvata lugens (Stål) and Sogatella furcifera Horvath) are the most destructive rice pests throughout southeastern and eastern Asia. Planthopper feeding often causes “hopper burn” and reduces rice yields. Currently, insecticide use is the sole pest management option available to most Chinese farmers. Because pesticide use may have undesirable effects, environmentally sound and sustainable management alternatives are urgently needed. In a two-year field study at the Wuyishan Experimental Station of the Institute of Applied Ecology (IAE), Fujian Agriculture and Forestry University (FAFU), we evaluated the effects of polycultural manipulation on the abundance, sexual differentiation and wing dimorphism of rice planthoppers. The polycultural manipulation was arranged in mosaic patterns of paddy plots intercropped with non-paddy plots including chili pepper, ginger, maize and peanut plants. Monocultural fields of paddy plants were used as controls. Polycultural manipulation significantly reduced the abundance of total planthoppers and nymphs of N. lugens and S. furcifera. The number of overall planthoppers decreased on average by 49% and 55% in 2007 and 2008, respectively. However, polycultural manipulation had no impact on the proportions of female or macropterous planthoppers. The resource concentration and associational resistance hypotheses may explain these results. In polycultural fields, non-rice species may mask the chemical or visual attractants of rice, making them less apparent, and microhabitat differences in the levels of secondary compounds or in plant quality may also disrupt planthopper orientation.

Biodiversity, nutrition and livelihoods in aquatic rice-based ecosystems

The cultivation of rice in irrigated, rain-fed and deepwater systems often offers a suitable environment for fish and other aquatic organisms. Indeed, it comes as no surprise for those who produce rice that a rich source of biological diversity is to be found in rice-based ecosystems. Wild and gathered foods, from the aquatic habitat, provide important diversity, nutrition and food security as food resources from ricefield environments supply essential nutrients that are not adequately found in the diet. Yet this rich and important diversity is often not recognized in national statistics, policies, and legal frameworks. This paper illustrates the critical importance of aquatic biodiversity for poor rice-farming households based on findings from several years of research in Cambodia, Lao PDR, China and Vietnam. An understanding of the value of aquatic biodiversity from rice-based ecosystems for food and nutrition needs to be well integrated into national agricultural systems that embrace the concepts of an ecosystem approach and the important role of agrobiodiversity for people and the environment.

Use and availability of aquatic biodiversity in rice-based ecosystems of Southeast Asia

Use and availability of aquatic biodiversity in rice-based ecosystems of Southeast Asia

Basic human nutrition requirements and dietary diversity in rice-based aquatic ecosystems

The human organism requires a diverse diet in order to meet its nutrient requirements. In the agriculture sector, dietary energy supply had long been a proxy for adequate nutrition. Thus, one guiding principle of the green revolution was to supply dietary energy with the expectation that the nutrients would naturally follow. This has proved false. FAO calculates that there are 840 million undernourished people (FAO, 2000–2005c), yet there are billions with micronutrient deficiencies, more than half of whom have at least adequate energy intakes (FAO, 2004). Rice, and any starchy staple, is capable of providing all the energy required—but dietary diversity is necessary to provide the full range of nutrients. A rice-based aquatic ecosystem is a particularly rich source of biodiversity and—by extension—of dietary diversity. Easily measured and documented nutrient deficiencies include vitamin A, several B vitamins, calcium, iron, zinc, iodine, sulphur-containing amino acids and lysine, and fatty acids of the n-3 series. Recent studies have suggested that the rich utilized aquatic biodiversity in the rice-based ecosystems of Laos, Cambodia, China and Viet Nam could supply most of these nutrients (Halwart, 2003; Halwart and Bartley, 2005). Yet these populations suffer a high rate of micronutrient deficiencies and problems related to nutritional status such as low birth weights, high maternal and infant mortality, and stunting, wasting and underweight in children (FAO, 2005b; Meusch et al., 2003). The contributions to nutrition from these ecosystems are often unrecognized and unacknowledged by researchers, and are often under-appreciated by the local people. Foods outside the formal economy are not included in FAO statistical databases (e.g. Food Balance Sheets, FAO, 2005a), nor have most nutrition surveys attempted to document the differentiation in foods consumed in fine-enough detail to assess the importance of these ecosystems for the nutrition of rural populations. Many food composition tables and databases fail to capture individual foods by variety/strain/breed, preferring instead to group foods generically. Nevertheless, there is an ever-increasing body of data showing that individual cultivars, strains, breeds of the same species can have markedly different nutrient contents (Kennedy and Burlingame, 2003; Huang et al., 1999), and recent studies show that rural people are capable of identifying foods from a genetic resource perspective (Kennedy et al., 2005). With increased attention to local aquatic ecosystems, both for food composition and consumption activities, the contribution of these aquatic species can be properly assessed and their importance to the nutrition of rural people can be established, and ultimately preserved. References

Biodiversity and nutrition in rice-based aquatic ecosystems

The cultivation of most rice crops in irrigated, rainfed and deepwater systems offers a suitable environment for fish and other aquatic organisms. Indeed, it comes as no surprise for those who produce rice that a rich source of biological diversity is to be found in rice-based ecosystems. Wild and gathered foods, from the aquatic habitat, provide important diversity, nutrition and food security as food resources from ricefield environments supply essential nutrients that are not adequately found in the diet. Development plans that focus only on increasing yields of rice may possibly give people more rice to eat, but at the same time may take away many of the aquatic animals and plants harvested from and around the rice fields. Many of the aquatic organisms found in rice ecosystems also play an important role as biological control agents of vectors and pests. Moreover, farmers have experienced that the concurrent culture of fish with rice often increases rice yields. This is reflected in an increase of the net income which is reportedly 7–65% higher on rice-fish farms as compared to rice monoculture farms. Rice fields may also harbour species which are under threat of extinction. The understanding for the value of aquatic biodiversity from rice-based ecosystems for food and nutrition needs to be well integrated into national agricultural systems that embrace the concepts of an ecosystem approach and the important role of agrobiodiversity for people and the environment.

FAO Regional Technical Expert Workshop on aquatic biodiversity, its nutritional composition, and human consumption in rice-based systems

The FAO Regional Technical Expert Workshop on aquatic biodiversity, its nutrient composition, and human consumption in rice-based systems was convened at the FAO Regional Office in Bangkok, Thailand, 8–10 December 2004. The aim of the meeting was to bring nutritionists, fishery resource managers and development agencies together to discuss the various aspects of aquatic biodiversity and nutrition in rice-based farming with a view to establishing baseline information, identifying information gaps, and ultimately formulating recommendations for integrated development activities. The meeting concluded that the available information on composition of aquatic species and their consumption is limited, and sometimes inadequate. Local information sources on composition and consumption need to be identified and incorporated into current rice-based ecosystem biodiversity databases. The use of existing networks for information exchange and strategic partnerships was emphasized. Household consumption studies linking aquatic biodiversity from rice-based ecosystems and nutrition need to be done in the region. Methods need to improve, however, and a step-wise combination of techniques appears to be the most promising approach. It is necessary to develop aquatic resource profiles to guide the selection of key species which must be linked to specific seasons and habitats. Financial resources need to be identified and strategic partnerships made to plan and implement studies that will advance our knowledge on aquatic biodiversity in rice-based ecosystems, the way it is used by rural people, and its impact on their nutrition. The Workshop was attended by 25 participants including regional participants (Cambodia, China, Lao PDR, Thailand and Viet Nam), resource persons (Mekong River Commission (MRC), WorldWide Fund for Nature (WWF), Institute of Aquaculture—Stirling University, European Union), the FAO Technical Secretariat and support staff. In the section that follows this report are the abstracts of presentations given during the Workshop.