855 resultados para vegetation attributes


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The Maximum Capture problem (MAXCAP) is a decision model that addresses the issue of location in a competitive environment. This paper presents a new approach to determine which store s attributes (other than distance) should be included in the newMarket Capture Models and how they ought to be reflected using the Multiplicative Competitive Interaction model. The methodology involves the design and development of a survey; and the application of factor analysis and ordinary least squares. Themethodology has been applied to the supermarket sector in two different scenarios: Milton Keynes (Great Britain) and Barcelona (Spain).

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Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept. The guilds constitute a valuable ecological tool, because they allow conducting comparisons among environments under different conditions. The ants can be used as ecological indicators, mainly for the monitoring of degraded forest areas. The aim of this research was to study guild organization among the epigeous Formicidae living in Atlantic forest remnants of the State of São Paulo, Brazil. Ant collections were performed in three distinct Atlantic forest biome areas: arboreal littoral vegetation ("restinga") (Cananéia), semideciduous seasonal forest (Piracicaba) and dense ombrophylousforest (Pariquera-Açu). After identification, the ants were grouped into guilds, based on the ecological attributes of behavior and habit, according to the literature. Nine guilds were found; the semideciduous seasonal forest ecosystem presented eight of them, followed by the arboreal sandbank (7) and dense ombrophylous forest (6). The guilds found were: litter omnivorous and scavengers, granivorous species, specialist predators living in litter and soil, litter generalist predators, subterranean mealybug-dependent species, army ants, dominant or subdominants arboreal, that occasionally forage on the ground, soil or litter dominant and fungus-growers, using feces and insect body fragments. The guilds found can be used in the monitoring of the mirmecofauna in the Atlantic Forest biome, supplying insights for further ecological studies.

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Forensic Entomology research has been concentrated in only a few localities of the "Cerrado" vegetation, the Brazilian Savannah. The present study had, as its objective, an examination of the diversity of arthropod fauna associated with the carcasses of Sus scrofa (Linnaeus) in this biome. The study was conducted during the dry and humid periods in two Cerrado vegetation profiles of the State of Minas Gerais. The decaying process was slower and greater quantities of arthropods were collected during the dry period. Insects represented 99% of 161,116 arthropods collected. The majority of these were Diptera (80.2%) and Coleoptera (8.8%). The entomofauna belong to 85 families and at least 212 species. Diptera were represented by 31 families and at least 132 species. Sarcophagidae (Diptera) and Scarabaeidae (Coleoptera) were the richest groups. Oxysarcodexia (Sarcophagidae) presented the largest number of attracted species, however none of these species bred in the carcasses. The Coleoptera collected belong to at least 50 species of 21 families. Among these species, Dermestes maculatus and Necrobia rufipes were observed breeding in the carcasses. This study showed species with potential importance for estimating the postmortem interval (PMI), indicative of seasonal and environmental type located.

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This article examines the private mechanisms used to safeguard quality in auditing, with a view to defining rules capable of facilitating the performance of market forces. An outline is given of a general theory of private quality assurance in auditing, based on the use of quasi-rents to self-enforce quality dimensions. Particular attention is paid to the role of fee income diversification as the key ingredient of private incentives for audit quality. The role of public regulation is then situated in the context defined by the presence of these safeguard mechanisms. This helps in defining the content of rules and the function of regulatory bodies in facilitating and strengthening the protective operation of the market. By making sense of the interaction between regulation, quality attributes and private safeguards, the analysis helps to evaluate the relative merits of different regulatory options.

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Polistine wasps are important in Neotropical ecosystems due to their ubiquity and diversity. Inventories have not adequately considered spatial attributes of collected specimens. Spatial data on biodiversity are important for study and mitigation of anthropogenic impacts over natural ecosystems and for protecting species. We described and analyzed local-scale spatial patterns of collecting records of wasp species, as well as spatial variation of diversity descriptors in a 2500-hectare area of an Amazon forest in Brazil. Rare species comprised the largest fraction of the fauna. Close range spatial effects were detected for most of the more common species, with clustering of presence-data at short distances. Larger spatial lag effects could also be identified in some species, constituting probably cases of exogenous autocorrelation and candidates for explanations based on environmental factors. In a few cases, significant or near significant correlations were found between five species (of Agelaia, Angiopolybia, and Mischocyttarus) and three studied environmental variables: distance to nearest stream, terrain altitude, and the type of forest canopy. However, association between these factors and biodiversity variables were generally low. When used as predictors of polistine richness in a linear multiple regression, only the coefficient for the forest canopy variable resulted significant. Some level of prediction of wasp diversity variables can be attained based on environmental variables, especially vegetation structure. Large-scale landscape and regional studies should be scheduled to address this issue.

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The effects of forest conversion to agricultural land uses on assemblages of aquatic insects were analyzed in subtropical streams. Organisms and environmental variables were collected in six low-order streams: three streams located in a forested area, and three in areas converted to agricultural land uses. We expected that the aquatic insects' assemblage attributes would be significantly affected by forest conversion, as well as by environmental variables. Streams in converted areas presented lower species richness, abundance and proportion of sensitive insect taxa. The ANOSIM test evidenced strong difference in EPT assemblage structure between streams of forested and converted areas. The ISA test evidenced several EPT genera with high specificity to streams in forested areas and only one genus related to streams in converted areas. Thus, the impacts of the conversion of forested area to agricultural land uses have significantly affected the EPT assemblages, while environmental variables were not affected. We suggest that the effects detected can be influenced by two processes related to vegetation cover: i) lower input of allochthonous material, and ii) increased input of fine sediments in streams draining converted areas.

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The DOT is in the process of replanting all the roadsides on state primary highways to native grasses and wildflowers. While the existing vegetation may look nice, it is not functioning as well as needed for roadside purposes such as erosion control, water infiltration or weed competition. The DOT currently spends nearly $3 million each year to clean ditches, remove silt, and spray and mow weeds. The DOT believes the native vegetation, once established, will provide sufficient benefits and reduced maintenance costs to warrant replacing the existing vegetation.

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This work aimed to measure and analyze total rainfall (P), rainfall intensity and five-day antecedent rainfall effects on runoff (R); to compare measured and simulated R values using the Soil Conservation Service Curve Number method (CN) for each rainfall event; and to establish average R/P ratios for observed R values. A one-year (07/01/96 to 06/30/97) rainfall-runoff data study was carried out in the Capetinga watershed (962.4 ha), located at the Federal District of Brazil, 47° 52' longitude West and 15° 52' latitude South. Soils of the watershed were predominantly covered by natural vegetation. Total rainfall and runoff for the period were 1,744 and 52.5 mm, respectively, providing R/P of 3% and suggesting that watershed physical characteristics favored water infiltration into the soil. A multivariate regression analysis for 31 main rainfall-runoff events totaling 781.9 and 51.0 mm, respectively, indicated that the amount of runoff was only dependent upon rainfall volume. Simulated values of total runoff were underestimated about 15% when using CN method and an area-weighted average of the CN based on published values. On the other hand, when average values of CN were calculated for the watershed, total runoff was overestimated about 39%, suggesting that CN method shoud be used with care in areas under natural vegetation.

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Echocardiography is a key tool in the diagnosis of infective endocarditis. Although transthoracic echocardiography is the first step in the work-up, transoesophageal echocardiography is mandatory for the evaluation of the exact extent of the infectious process. Indeed, perivalvular abscess can fistulate towards different heart chambers, leading sometimes to critical clinical situations.

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Tiivistelmä: Karjalan tasavallan Vodlajärven kansallispuistossa sijaitsevan Lishkansuon kasvillisuus

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Tiivistelmä: Kasvillisuus ja CO2-tase käytöstä vapautuneella turvetuotantoalueella Kihniön Aitonevalla

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Based on conclusions drawn from general climatic impact assessment in mountain regions, the review synthesizes results relevant to the European Alps published mainly from 1994 onward in the fields of population genetics, ecophysiology, phenology, phytogeography, modeling, paleoecology and vegetation dynamics. Other important factors of global change interacting synergistically with climatic factors are also mentioned, such as atmospheric CO2 concentration, eutrophication, ozone or changes in land-use. Topics addressed are general species distribution and populations (persistence, acclimation, genetic variability, dispersal, fragmentation, plant/animal interaction, species richness, conservation), potential response of vegetation (ecotonal shift - area, physiography - changes in the composition, structural changes), phenology, growth and productivity, and landscape. In conclusion, the European Alps appear to have a natural inertia and thus to tolerate an increase of 1-2 K of mean air temperature as far as plant species and ecosystems are concerned in general. However, the impact of land-use is very likely to negate this buffer in many areas. For a change of the order of 3 K or more, profound changes may be expected.