Efeito das relações bióticas sobre o estabelecimento de macroalgas de ecossistemas lóticos tropicais: interação com microalgas e pressão por herbivoria

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A comparative study of Odonata (Insecta) in aquatic ecosystems with distinct characteristics

The objective of this study was to compare the richness and density of Odonata larvae in four distinct environments: lotic with large pollutant loads, lotic with small pollutant loads, lentic disconnected from a river and lentic connected to a river, as well as to record the physical and chemical parameters of the water in the four environments. We identified a total of 1,302 Odonata larvae in the four habitats. The environmental variables measured were: dissolved oxygen, pH, conductivity, suspended matter, air and water temperature, precipitation, depth, and the biomass of the macrophytes. The lentic habitats exhibited a greater Odonata larvae density in relation to the lotic habitats, except during April and December of 2006. The Guareí River, however, presented an elevated conductivity, possibly because of a greater quantity of pollutants it received during the period between June and September of 2006, and it showed a higher density of Odonata larvae in comparison to the Paranapanema River. The temperature and the dissolved oxygen on the water surface were, respectively, greater and smaller in the lakes in comparison to the rivers. In spite of the Odonata density being higher in the lentic ecosystems in comparison to the lotic, the richness was not altered during the period studied. Nevertheless, the genera composition was distinct, showing that some taxa show a certain preference for certain types of ecosystems like Calopterygidae and Neogomphus, which were shown exclusively in the Paranapanema River.

Avaliação das áreas de conflito de uso em APP da microbacia do alto água fria, Bofete (SP)

The misuse of land by man and is causing serious problems to the environment, resulting in ecological imbalance and depletion of natural resources, especially when it comes to areas of permanent preservation, that ecosystems are essential for balance and water conservation importance . Conflicts of land use is a major cause of silting of rivers and water bodies, causing significant losses in soil and decaying natural water resources both in quantity and in quality. Within this scenario, the planning becomes essential for the control of environmental impacts to the environment factor. This study aimed to evaluate land use conflicts in permanent preservation areas of the stream Água Fria watershed, Bofete (SP) using Geographic Information System and satellite image of LANDSAT - 5 of 2010, scale 1:50000. The results show that 51.16% of the permanent preservation areas of the watershed are conflicting, especially for pasture (88.94%) and reforestation with eucalyptus (11.06%). The GIS IDRISI Selva and Cartalinx along with GIS techniques demonstrated speed and efficiency in identifying, measuring and editing maps of land use, preservation and ongoing conflicts in areas of permanent preservation.

Avaliação das áreas de conflito de uso em APP na microbacia do ribeirão Morro Grande

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation’s water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation’s river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html).

Spatial statistical models that use flow and stream distance

We develop spatial statistical models for stream networks that can estimate relationships between a response variable and other covariates, make predictions at unsampled locations, and predict an average or total for a stream or a stream segment. There have been very few attempts to develop valid spatial covariance models that incorporate flow, stream distance, or both. The application of typical spatial autocovariance functions based on Euclidean distance, such as the spherical covariance model, are not valid when using stream distance. In this paper we develop a large class of valid models that incorporate flow and stream distance by using spatial moving averages. These methods integrate a moving average function, or kernel, against a white noise process. By running the moving average function upstream from a location, we develop models that use flow, and by construction they are valid models based on stream distance. We show that with proper weighting, many of the usual spatial models based on Euclidean distance have a counterpart for stream networks. Using sulfate concentrations from an example data set, the Maryland Biological Stream Survey (MBSS), we show that models using flow may be more appropriate than models that only use stream distance. For the MBSS data set, we use restricted maximum likelihood to fit a valid covariance matrix that uses flow and stream distance, and then we use this covariance matrix to estimate fixed effects and make kriging and block kriging predictions.

Feral swine damage and damage management in forested ecosystems

Invasive feral swine (Sus scrofa) cause deleterious impacts to ecosystem processes and functioning throughout their worldwide distribution, including forested ecosystems in the United States. Unfortunately, many feral swine damage management programs are conducted in a piecemeal fashion, are not adequately funded, and lack clearly stated or realistic objectives. This review paper identifies damage caused by feral swine to forest resources and presents techniques used to prevent and control feral swine damage. Concluding points related to planning a feral swine damage management program are: (1) the value of using a variety of techniques in an integrated fashion cannot be overstated; (2) there is value in using indices for both feral swine populations and their damage pre and post management activities; (3) innovative technologies will increasing be of value in the pursuit of feral swine damage reduction; and (4) though not appropriate in every situation, there is value in involving the public in feral swine damage management decisions and activities.

Analysis of the environmental impact on a stream: is only tannery to blame?

The contribution of wastewater from a tannery industry to the pollution of a stream was investigated. The main parameters studied were biochemical oxygen demand, chemical oxygen demand, chromium, dissolved oxygen, fecal and total conforms, nitrogen, oils and greases, pH, phosphorous, sulfides, suspended solids, turbidity, and volatile solids. Three sampling points were located: (I) at the discharge point of tannery wastewater, (2) 50 m upstream, and (3) 80 m downstream of discharge point. Also was investigated the pollution at the stream source.

Laser Optical Plankton Counter and Zooscan intercomparison in tropical and subtropical marine ecosystems

Two recently developed instruments, the Laser Optical Plankton Counter (LOPC) and the Zooscan, have been applied to study zooplankton biomass size spectra in tropical and subtropical marine ecosystems off Brazil. Both technologies rely on optical measurements of particles and may potentially be used in zooplankton monitoring programs. Vertical profiles of the LOPC installed in a 200 mu m ring net have been obtained from diverse environmental settings ranging from turbid and nearshore waters to oligotrophic open ocean conditions. Net samples were analyzed on the Zooscan and counted under a microscope. Particle biovolume in the study area estimated with the LOPC correlated with plankton displacement volume from the net samples, but there was no significant relationship between total areal zooplankton biomass determined with LOPC and the Zooscan. Apparently, normalized biomass size spectra (NBSS) of LOPC and Zooscan overlapped for particles in the size range of 500 to 1500 mu m in equivalent spherical diameter (ESD), especially at open ocean stations. However, the distribution of particles into five size classes was statistically different between both instruments at 24 of 28 stations. The disparities arise from unequal flow estimates, from different sampling efficiencies of LOPC tunnel and net for large and small particles, and possibly from the interference of non-zooplankton material in the LOPC signal. Ecosystem properties and technical differences therefore limit the direct comparability of the NBSS slopes obtained with both instruments during this study, and their results should be regarded as complementary.

Integrated ecological risk assessment of pesticides in tropical ecosystems: A case study with carbofuran in Brazil

The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Environ. Toxicol. Chem. 2012;31:437-445. (C) 2011 SETAC

Masking environmental feedback : Misfits between institutions and ecosystems in Belize and Thailand

The thesis analyses relationships between ecological and social systems in the context of coastal ecosystems. It examines human impacts from resource extraction and addresses management and governance behind resource exploitation. The main premises are that a lack of ecological knowledge leads to poor ecosystem management and that the dichotomy between social and natural systems is an artificial one. The thesis illustrates the importance of basing resource management on the ecological conditions of the resource and its ecosystem. It also demonstrates the necessity of accounting for the human dimension in ecosystem management and the challenges of organising human actions for sustainable use of ecosystem services in the face of economic incentives that push users towards short-term extraction. Many Caribbean coral reefs have undergone a shift from coral to macroalgal domination. An experiment on Glovers Reef Atoll in Belize manually cleared patch reefs in a no-take zone and a fished zone (Papers I and II). The study hypothesised that overfishing has reduced herbivorous fish populations that control macroalgae growth. Overall, management had no significant effect on fish abundance and the impacts of the algal reduction were short-lived. This illustrated that the benefits of setting aside marine reserves in impacted environments should not be taken for granted. Papers III and IV studied the development of the lobster and conch fisheries in Belize, and the shrimp farming industry in Thailand respectively. These studies found that environmental feedback can be masked to give the impression of resource abundance through sequential exploitation. In both cases inadequate property rights contributed to this unsustainable resource use. The final paper (V) compared the responses to changes in the resource by the lobster fisheries in Belize and Maine in terms of institutions, organisations and their role in management. In contrast to Maine’s, the Belize system seems to lack social mechanisms for responding effectively to environmental feedback. The results illustrate the importance of organisational and institutional diversity that incorporate ecological knowledge, respond to ecosystem feedback and provide a social context for learning from and adapting to change.

Changes in species richness and diversity of cryptogrammic communities in páramo ecosystems

Universidad Técnica Particular de Loja

Planktonic potential CO2 emission calculation: preliminary results by applying an adapted enzymatic methodology to marine ecosystems

[EN]Isocitrate Dehydrogenase (IDH) is a key enzyme in the Krebs cycle, being responsible for the production of one of the three CO2 molecules related to cellular respiration. In order to measure the potential CO2 production linked to the marine planktonic community we have adapted an enzymatic methodology. Preliminary results show that different proportions of autotrophs, heterotrophs and mixotrophs and their metabolic pathways, lead to different relationships between potential CO2 emission and potential O2 consumption during cellular respiration. Although more experiments need to be made, this methodology is leading to a better understanding of cellular respiration in marine samples and their impact on the food chain, vertical Carbon flux and the current sequestering capacity for anthropogenic CO2.