Assimilation Of Resources Research Articles

Ризики та загрози господарській діяльності під час засвоєння ресурсів у береговій зоні морів

The article discusses and systematizes the most important risks associated with the economic assimilation of natural resources of the coastal zone of the seas. This is necessary to strengthen the fight against negative natural and artificial processes that negatively affect the state of the coastal zone and the high quality of the coastal environment. This question has always been relevant, but there is not a single special work on this topic in Coastal Studies. To achieve the goal of this work, the following tasks were solved: a) adopt the basic concepts and definitions in the text of the article; B) identify risks in the coastal zone, as opposed to risks on land; C) type risks in the coastal zone of the seas; d) analyze each of the risks. We have reviewed and analyzed the 10 most important risks and indicated ways and means to overcome them. Each differs from all the others within a particular sea in origin, geological structure, sediment balance, biogenic and hydrochemical features, morphology and dynamics. Therefore, anthropogenic impact and natural hazards create different types of risks and threats to the nature of the coastal zone, on the one hand, and on the other — for economic objects and buildings. A critical review of research materials in the coastal zone of the Black and Azov seas (examples on other seas are taken for comparison) showed the ability to identify the ten most important risks in the process of assimilation of Natural Resources in the coastal zone and perform an appropriate natural justification. Their analysis showed that the most important and dangerous risks are associated with a violation of the balance of sediments, with the lack of data on the long-term dynamics of the abrasive and accumulative Coast, underestimation of the interaction processes of the surface and underwater parts of the coastal zone, with the unsuccessful use of hydraulic structures that do not harmonize with the coastal environment of a particular lithodynamic cell. It was most effective to take into account a certain set of risks and threats, within different lithodynamic systems, with different physical and geographical conditions, with different goals and objectives for the natural justification of a particular design in the coastal zone of the sea. In this aggregate, each type of risk (threat).

Экономическая политика Испании на новом этапе европейской интеграции

On April 29, 2021, IMEMO RAS held a round table chaired by the Academician of the Russian Academy of Sciences, a member of the Directorate of IMEMO RAS V.G. Baranovsky and organized by the Center of European Studies of the IMEMO RAS under the leadership of Candidate of Historical Sciences Yu.D. Kvashnin. The round table participants analyzed the key problems of modern Spain's economy in the context of the emergence of new challenges of a global and regional nature. The discussion focused on the dynamics of the Spanish economy and its reaction to both a set of internal problems and external crises. In the context of unprecedented support for citizens and businesses from European regulators, Spain has become one of the primary beneficiaries in the distribution of European funds. Until 2027, the country will receive 170 billion euros. On the one hand, this will significantly boost the potential of the national economy in the long term regarding the country's role for the EU resilience and sustainability. The country's business is capable of significantly accelerating the economy through a successful foreign economic sector. The EU funds' emphasis on the Green Deal and the dominance of a government coalition with a special focus on the Green Agenda create favorable conditions for the promotion of Spanish energy multinationals at the global level. Nevertheless, Spain has been facing a number of socio-economic and political problems for a long time. Among them are high unemployment rate, significant budget deficit and political instability. The pandemic has greatly exacerbated the complexity of this range of problems. Their solution depends on the ability of the national political establishment to consolidate the existing levers and to ensure sustainable development of the economy through reforms. The assimilation of all-European fund resources, record for the country, greatly simplifies the tasks Spain is facing, but a political consensus is needed. The main speakers of the event included A.V. Avilova, K.A. Nikulin and G.N. Ponedelko from the Center of European Studies of the IMEMO RAS; I.L. Prokhorenko from the Department of International Political Problems of the IMEMO RAS; V.M. Tayar and P.P.Yakovlev from the Center of Iberian Studies of the Institute of Latin America RAS; T.V. Sidorenko from the National Research University Higher School of Economics; and T.I. Malashenko from the Department of Business Administration of the joint venture 'Digital Industrial Platform'. The review of the round table discussions was prepared by Kirill A. Nikulin, the junior researcher of the Center of European Studies of the IMEMO RAS (nikulin@imemo.ru, ORCID: 0000-0001-6314-0447.

Molecular Properties and New Potentials of Plant Nepenthesins.

Nepenthesins are aspartic proteases (APs) categorized under the A1B subfamily. Due to nepenthesin-specific sequence features, the A1B subfamily is also named nepenthesin-type aspartic proteases (NEPs). Nepenthesins are mostly known from the pitcher fluid of the carnivorous plant Nepenthes, where they are availed for the hydrolyzation of insect protein required for the assimilation of insect nitrogen resources. However, nepenthesins are widely distributed within the plant kingdom and play significant roles in plant species other than Nepenthes. Although they have received limited attention when compared to other members of the subfamily, current data indicates that they have exceptional molecular and biochemical properties and new potentials as fungal-resistance genes. In the current review, we provide insights into the current knowledge on the molecular and biochemical properties of plant nepenthesins and highlights that future focus on them may have strong potentials for industrial applications and crop trait improvement.

Verbal aspects of China’s vocal art system

Verbal aspects of China’s vocal art system

Microbiota associated with the skin, gills, and gut of the fish Parachondrostoma toxostoma from the Rhône basin

Abstract The close relationships between hosts and their microbiota underlie the current concept of holobionts. This biological entity enlarges our perception of the genomic diversity supported by individuals/species and the potential abilities of hosts to respond to the environment. We investigated a total of 54 specimens of the sofie fish Parachrondrostoma toxostoma (Pt) for the taxonomic and functional composition of microbiota associated with the skin, gills, and gut tissues. Five wild populations from the Ardèche and Durance river basins in the Mediterranean part of the large catchment of the Rhône (southern France) were compared. We found that the skin microbiota was more diverse and variable in bacterial community composition than the gut microbiota. These differences suggest that different deterministic factors underlie the composition of these bacterial communities, resulting in tissue‐specific variation of the microbiota composition between wild fish populations inhabiting two rivers. Microbiota diversity and composition differed between wild Pt populations at both regional and local spatial scales. Using the Picrust tool, the taxonomic variation of the microbiota composition in the river fish populations could be associated with the enrichment of predicted metabolic pathways. In particular, carbohydrate metabolism was more represented and xenobiotic biodegradation pathways less represented in the gut microbiota of Pt populations from the Ardèche than of those from the Durance. This result suggests variability in the ability to acclimate to environmental features through the assimilation of food resources from plants and the detoxification of xenobiotic components. This study opens perspectives in the detection of subtle shifts in environmental features through the description of the microbiota composition, and in the potential prediction of the functional capacities of species to acclimate.

Innovation capability of clusters: understanding the innovation of geographic business networks

Purpose – This paper aims to explore innovation in geographic business networks and to propose a model of innovation capability of cluster. The premise is that innovation is a necessity for firms and relations inter firms is an alternative for it to occur. Among these relationships, clusters stand out, with studies showing that firms in clusters tend to be more innovative. Design/methodology/approach –This, we conducted an exploratory research with two clusters: emerging cluster of Alto do Camaqua , in Brazil and growing cluster of Sisteron , in France.The cases were analyzed from elements previously established in the literature: context, collective strategy, public policy, commercialization, pro-activity, external relations, transmission collaboration, assimilation, transformation and application of knowledge, governance, infrastructure, financial resources and human resources. Findings – We arrived to a model of cluster innovation capability, composed by the strategic management, relationships and learning, technological and marketing development and operational management. Originality/value –The proposed model is a dinamic model as capabilities vary in their intensities according to the development stage of the cluster and its maturity time.

Tropical mussels Perna perna and P. viridis (Bivalvia: Mytilidae): Bottom or suspended culture?

Growth and survival of size-classes of the green Perna viridis and the brown P. perna mussels were compared in suspended and bottom culture systems in the Southern Caribbean Sea. The size-classes (juveniles, medium-size and adults) were defined in relation to somatic and reproductive characteristics of both species. Survival of P. viridis in bottom culture was close to 100% in all size groups, while in P. perna was between 75 and 80% in juveniles and medium-size and 63% in adults. Survival of P. perna in suspended culture was higher than 85% for juvenile and medium-size individuals and <60% in adults, while in P. viridis was between 60 and 70% in juveniles and medium-size and 40% in adults. Perna perna in suspended culture showed higher growth and survival rates, probably related to higher availability of phytoplanktonic biomass while on bottom culture, where seston levels were higher, P. viridis reached a higher growth rate suggesting physiological adaptations for efficient assimilation of available food resources in this environment. The results show that the culture strategy of the tropical mussel species to obtain a higher performance is different, recommending the cultivation of P. perna in suspended systems and P. viridis in bottom systems.

Using stable isotope approach to quantify pond dam impacts on isotopic niches and assimilation of resources by invertebrates in temporary streams: a case study

Fishponds built across streams can greatly affect their functioning, especially through loss of ecological continuity but also changes in water availability and trophic resources. Yet, their consequences on communities and stream functioning remain largely understudied. We investigated effects of fishpond dams on the trophic ecology of macroinvertebrate communities in temporary low-order streams using C and N stable isotopes. Food resources and macroinvertebrates were sampled in one upstream and one downstream site of two temporary streams, one stream without (reference stream) versus one with a fishpond (impacted stream) and used for isotopic analyses. Results suggested moderate effects of fishponds on the upstream tributaries. In contrast, at the downstream impacted site, ten times higher macroinvertebrate biomass and modifications in the trophic niches were recorded, likely due to changes in resource availability/quality and dam-related hydrology. By modifying the food sources as well as water fluxes, fishpond dams tend to alter macroinvertebrate communities but also shift the trophic dynamics downstream. This assessment stresses the need for exploring their impacts on food webs and nutrient fluxes at larger downstream distances to better understand their effects before drawing conclusions in regard to their management.

Honey bees overwintering in a southern climate: longitudinal effects of nutrition and queen age on colony-level molecular physiology and performance

Honey bee colony nutritional ecology relies on the acquisition and assimilation of floral resources across a landscape with changing forage conditions. Here, we examined the impact of nutrition and queen age on colony health across extended periods of reduced forage in a southern climate. We measured conventional hive metrics as well as colony-level gene expression of eight immune-related genes and three recently identified homologs of vitellogenin (vg), a storage glycolipoprotein central to colony nutritional state, immunity, oxidative stress resistance and life span regulation. Across three apiary sites, concurrent longitudinal changes in colony-level gene expression and nutritional state reflected the production of diutinus (winter) bees physiologically altered for long-term nutrient storage. Brood production by young queens was significantly greater than that of old queens, and was augmented by feeding colonies supplemental pollen. Expression analyses of recently identified vg homologs (vg-like-A, -B, and -C) revealed distinct patterns that correlated with colony performance, phenology, and immune-related gene transcript levels. Our findings provide new insights into dynamics underlying managed colony performance on a large scale. Colony-level, molecular physiological profiling is a promising approach to effectively identify factors influencing honey bee health in future landscape and nutrition studies.

Maximizing Success With Rapid Sequence Intubations.

Within emergency care settings, rapid sequence intubation (RSI) is frequently used to secure a definitive airway (i.e., endotracheal tube) to provide optimal oxygenation and ventilation in critically ill patients of all ages. For providers in these settings, a deeper understanding of the indications, associated medications, and adjunctive techniques may maximize success with this common procedure. Identification of difficult airways, using mnemonics and standardized criteria prior to the procedure allows, the clinician additional time for assimilation of additional resources and tools to increase the likelihood of first-pass success with intubation. This article describes tools for the procedure of RSI, including the "7 Ps" checklist of intubation.

An assessment of assumptions and uncertainty in deuterium-based estimates of terrestrial subsidies to aquatic consumers.

The deuterium ratio (2 H/1 H) in tissue is often used to estimate terrestrial subsidies to aquatic consumers because of strongly differentiated values between terrestrial and aquatic primary producers. However, quantitative deuterium-based analyses of terrestrial resource assimilation are highly dependent on several poorly defined assumptions. We explored the sensitivity of these estimates to assumptions regarding environmental water contributions to consumer deuterium content (ω) and algal photosynthetic hydrogen discrimination (εH ). We also tested whether 13 C/12 C and 2 H/1 H-based estimates of terrestrial resource assimilation give similar outcomes. The average of the 12 experiments that have directly estimated proportional contributions of environmental water to consumer tissue 2 H/1 H was 0.27±0.11 (mean ± SD), with similar values for invertebrates and fish. Conversely, of the 28 field studies that have used 2 H/1 H to characterize aquatic food webs, all but one assume a value that is less than our current best estimate, usually substantially less. A reanalysis of the raw data from four recent case studies indicates the calculated terrestrial contribution to aquatic consumers is extremely sensitive to this assumption. When the authors' original assumptions were used (i.e., ω=0.16±0.05), the estimated proportional contribution of terrestrial resources to aquatic consumers (θT ) averaged 29±17%, and when ω=0.27 was used the average estimated assimilation of allochthonous resources was ≈0.00. A compilation of published photosynthetic hydrogen discrimination values for microalgae averaged εH =-150±27‰ (SD, n=99), and a sensitivity analysis showed the outcomes of these calculations were also strongly influenced by uncertainty in εH . There was no statistical association between 13 C/12 C and 2 H/1 H-based estimates of terrestrial subsidies (r=-0.12, n=274). This analysis indicates that the assumptions in deuterium-based estimates of terrestrial resource assimilation are highly influential but poorly constrained; therefore, the impact of these assumptions on calculated outputs must be carefully assessed and thoroughly reported. Due to the highly uncertain assumptions inherent in deuterium-based analyses, we urge much more caution when using this approach to estimate terrestrial subsidies to consumers in aquatic ecosystems.

Art and intellectual disability: Exploratory evaluation of the diARTE programme

Abstract The present work offers an exploratory evaluation of the possible benefits of the diARTE programme. This programme was applied to a group of adults with mild intellectual disability (ID) and/or learning disorders from a pre-working centre in Seville (Spain). The intervention was characterized by the use of different artistic disciplines in order to improve their social skills. It was applied in eight sessions, each of them two hours long, for two months. Data on the possible benefits of the intervention were obtained in two ways: observation and interviews. Results suggest that there were improvements in self-knowledge and verbal and non-verbal ability, and learning and assimilation of artistic resources in order to deal with emotional situations.

Seasonal increases in fish trophic niche plasticity within a flood‐pulse river ecosystem (Tonle Sap Lake, Cambodia)

AbstractSpecies’ responses to seasonal environmental variation can influence trophic interactions and food web structure within an ecosystem. However, our ability to predict how species’ interactions will vary spatially and temporally in response to seasonal variation unfortunately remains inadequate within most ecosystems. Fish assemblages in the Tonle Sap Lake (TSL) of Cambodia—a dynamic flood‐pulse ecosystem—were studied for five years (2010–2014) using stable isotope and Bayesian statistical approaches to explore both within‐ and among‐species isotopic niche variation associated with seasonal flooding. Roughly 600 individual fish specimens were collected during 19 sampling events within the lake. We found that fishes within the same species tended to have a broader isotopic niche during the wet season, likely reflecting assimilation of resources from either a wider range of isotopically distinct prey items or a variety of habitats, or both. Furthermore, among‐species isotopic niches tended to overlap and range more broadly during the wet season, suggesting that floodplain inundation promotes exploitation of more diverse and similar resources by different species in the fish community. Our study highlights that the flood‐pulse dynamic that is typical of tropical aquatic ecosystems may be an essential element supporting freshwater fish community structure and the fish diversity that underpins the TSL food web. This flow regime is currently threatened by regional dam development, which may in turn impact the natural function and structure of the fishery food web.

Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes

AbstractLarge‐scale ecosystem disturbances can alter the flow of energy through food webs, but such processes are not well defined for Gulf of Mexico saltmarsh ecosystems vulnerable to multiple interacting stressors. The 2010 Deepwater Horizon (DWH) oil spill significantly affected the composition of terrestrial saltmarsh communities in Louisiana, and thus had the potential to alter energy pathways through terrestrial and aquatic food webs, with direct consequences for higher trophic‐level species restricted to these habitats. The Seaside Sparrow (Ammodramus maritimus) is endemic to saltmarshes and relies completely on the habitat and resources they provide; thus, the sparrows can serve as indicators of ecological change in response to disturbances. We analyzed food web pathways for birds residing in oiled and unoiled saltmarshes for the four years following the oil spill by quantifying the bulk carbon and nitrogen stable isotopes and fatty acid profiles of liver tissues, in addition to primary producers (e.g., marsh grasses) and invertebrate consumers representing the major energy resources in these systems. The stable isotope values of primary producers and most invertebrate consumers did not differ between oiled and unoiled sites, suggesting that the energy pathways within the food web were stable in spite of observed declines in these populations following the spill. The tracer profiles of the Seaside Sparrows confirmed that there was a nominal effect of oil on resource use or trophic position (TP). However, we detected significant inter‐annual variation in resource use by these birds; the sparrows occupied a lower TP and exhibited greater assimilation of resources derived from benthic–aquatic relative to terrestrial pathways in 2013 compared to other years. This distinction is likely attributable to the effects of Hurricane Isaac in 2012, whose significant storm surge extensively inundated the saltmarsh landscape. Despite widespread concern for the saltmarsh ecosystem after the DWH event, the significant effects noted at the population level translated into only subtle differences to the flow of energy through this food web. These results demonstrate varying responses to different degrees of landscape‐level disturbance, such as oil and hurricanes, and establish the need to better understand food web dynamics in these saltmarsh ecosystems.

Are you what you eat? Effects of trophic discrimination factors on estimates of food assimilation and trophic position with a new estimation method

A key factor for estimates of assimilation of resources and trophic position based on stable isotope data is the trophic discrimination factor (TDF). TDFs are assumed based on literature reviews, but may vary depending on a variety of factors, including the type of diet. We analyzed effects of alternative TDFs on estimates of assimilated resources and trophic positions for an omnivorous fish, Jenynsia multidentata, that reveals dietary variation among locations across a salinity gradient of a coastal lagoon in southern Brazil. We also compared estimates of foods ingested vs. foods assimilated. Food assimilation was estimated using carbon (δ13C) and nitrogen (δ15N) stable isotope ratios of food sources and consumer muscle tissue and an isotopic mixing model (SIAR); consumer trophic position (TP) was estimated from consumer and production source δ15N values. Diet was estimated using an index of relative importance based on frequency of occurrence and volumetric and numeric proportions of food items from stomach contents. The effect of variation in TDF on food assimilation and TP was tested using three alternative TDFs reported in review papers. We then created a new method that used food source-specific TDFs (reported separately for herbivores and carnivores) weighted in proportion to estimated assimilation of resources according to mixing model estimates to estimate TP (hereafter TPWAR). We found that plant material was not assimilated in a proportion similar to its importance in the diet of fish at a freshwater site, and the new method yielded best assimilation estimates. Animal material made greatest contributions to fish biomass irrespective of TDFs used in the mixing model. The new method produced TP estimates consistent with differences in estimated food assimilation along the salinity gradient. Our findings support the idea that food source-specific TDFs should be used in trophic studies of omnivores, since the method improved our ability to estimate trophic position and resource assimilation, two important ecological indicators.

Immune-Challenged Fish Up-Regulate Their Metabolic Scope to Support Locomotion.

Energy-based trade-offs occur when investment in one fitness-related trait diverts energy away from other traits. The extent to which such trade-offs are shaped by limits on the rate of conversion of energy ingested in food (e.g. carbohydrates) into chemical energy (ATP) by oxidative metabolism rather than by the amount of food ingested in the first place is, however, unclear. Here we tested whether the ATP required for mounting an immune response will lead to a trade-off with ATP available for physical activity in mosquitofish (Gambusia holbrooki). To this end, we challenged fish either with lipopolysaccharide (LPS) from E. coli or with Sheep Red Blood Cells (SRBC), and measured oxygen consumption at rest and during swimming at maximum speed 24h, 48h and 7 days post-challenge in order to estimate metabolic rates. Relative to saline-injected controls, only LPS-injected fish showed a significantly greater resting metabolic rate two days post-challenge and significantly higher maximal metabolic rates two and seven days post-challenge. This resulted in a significantly greater metabolic scope two days post-challenge, with LPS-fish transiently overcompensating by increasing maximal ATP production more than would be required for swimming in the absence of an immune challenge. LPS-challenged fish therefore increased their production of ATP to compensate physiologically for the energetic requirements of immune functioning. This response would avoid ATP shortages and allow fish to engage in an aerobically-challenging activity (swimming) even when simultaneously mounting an immune response. Nevertheless, relative to controls, both LPS- and SRBC-fish displayed reduced body mass gain one week post-injection, and LPS-fish actually lost mass. The concomitant increase in metabolic scope and reduced body mass gain of LPS-challenged fish indicates that immune-associated trade-offs are not likely to be shaped by limited oxidative metabolic capacities, but may instead result from limitations in the acquisition, assimilation or efficient use of resources.

Iron-Nutrient Interactions within Phytoplankton.

Iron limits photosynthetic activity in up to one third of the world’s oceans and in many fresh water environments. When studying the effects of Fe limitation on phytoplankton or their adaptation to low Fe environments, we must take into account the numerous cellular processes within which this micronutrient plays a central role. Due to its flexible redox chemistry, Fe is indispensable in enzymatic catalysis and electron transfer reactions and is therefore closely linked to the acquisition, assimilation and utilization of essential resources. Iron limitation will therefore influence a wide range of metabolic pathways within phytoplankton, most prominently photosynthesis. In this review, we map out four well-studied interactions between Fe and essential resources: nitrogen, manganese, copper and light. Data was compiled from both field and laboratory studies to shed light on larger scale questions such as the connection between metabolic pathways and ambient iron levels and the biogeographical distribution of phytoplankton species.

Assimilation of organic matter by two benthic consumers across gradients of latitude and nutrient enrichment

In modifying the traits of producers, coastal development and latitude may influence the assimilation of organic matter resources by consumers. The aim of the present study was to assess spatial variation across gradients of latitude and diffuse nitrogen loading in: (1) the N content of the seagrass Zostera muelleri and the mangrove Avicennia marina; and (2) the ultimate organic matter sources (inferred from δ15N and δ13C signatures) of the detritivorous mud whelk Pyrazus ebeninus and the predatory polychaete Nephtys australiensis. It was hypothesised that the organic matter sources of each of the two consumers would vary spatially, following patterns of spatial variation in the N content of primary producers. Sampling in 12 estuaries of New South Wales, Australia, spanning 7° of latitude and variable nutrient loading revealed that the nitrogen content of Z. muelleri was negatively correlated with latitude and nitrogen loading, but the nitrogen content of A. marina leaves followed only latitude. Of the four organic matter sources considered by the present study, Z. muelleri was consistently the main source passed through the trophic chain to the detritivore P. ebeninus and the predator N. australiensis. Nevertheless, the proportionate contribution of Z. muelleri and microphytobenthos to the carbon sources of N. australiensis varied with latitude, the former negatively and the latter positively. These relationships suggest that latitude may influence carbon sources of consumers by modifying producer physicochemical traits.

Uptake of nitrogen from natural food into fish in differently managed polyculture ponds using 15N as tracer

Food security in Asia depends significantly on small-scale pond aquaculture in which fish feed on external feeds and natural food resources. Little is known about the assimilation of natural food resources into fish. In order to elucidate the food web and nitrogen flows in a traditionally and a semi-intensively managed pond in Vietnam, δ13C and δ15N in pond inputs and fish were measured before and after the application of inorganic 15N at 1.1 and 0.4 % of total nitrogen. The applied 15N was traced through the biomass of stocked fish over 30 days. Under traditional management, grass carp was the dominant species in number and biomass. After 30 days, grass carp assimilated 1.2 % of the applied tracer through natural food resources. Filter feeders assimilated only 0.1–0.3 % of the tracer after 30 days because of the limited productivity in the traditionally managed pond. Nile tilapia showed the highest uptake rates over the 30 days, which demonstrated their ability to feed on a variety of natural food resources. In total, 2.6 % of the applied 15N was assimilated into fish biomass after 30 days. Under semi-intensive management, common carp was the main species numerically and assimilated 1.8 % of the tracer after 30 days. Grass carp was stocked at lower density, but had the highest biomass by the time of the experiment. Grass carp assimilated 0.2 % of the applied tracer suggesting a low contribution of natural food resources to its nutrition. Silver carp benefited most from the higher natural food resources. In total, 4.1 % of applied 15N was assimilated into fish biomass after 30 days. Traditional small-scale aquaculture of a grass carp-dominated polyculture has a lower assimilation efficiency of applied fertilizers into fish biomass than a common carp-dominated polyculture under semi-intensive management.

Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams.

It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna). Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches.