381,350 research outputs found
Water quality related macroinvertebrate community responses to environmental gradients in the Portoviejo River (Ecuador)
The Portoviejo River, located in the central western part of Ecuador, has been heavily impacted by damming, intensive agriculture and untreated wastewater discharge. Unfortunately, detailed information on the water quality and the ecological status of the Portoviejo River is not available, inhibiting decision-making and the development of water management plans. Therefore, the aims of this study were (1) to assess the ecological water quality, (2) to investigate the point along the environmental gradient where the most significant change in macroinvertebrate community occurs and (3) to find potential macroinvertebrate taxa that significantly change in abundance and frequency of occurrence along the Portoviejo River. To this end, macroinvertebrate and physico-chemical data were collected and hydro-morphological conditions were recorded at 31 locations during the dry season of 2015. The results showed that the ecological water quality of the sampling sites ranged from good to bad. In addition, the Threshold Indicator Taxa ANalysis was used to examine changes in macroinvertebrate communities and revealed significant community change points for sensitive taxa declining at a conductivity value of 930 (mu S.cm(-1)) and nitrate-nitrogen concentrations of 0.6 mg.L-1. In addition, the thresholds estimated for tolerant taxa were set at a conductivity value of 1430 mu S.cm(-1) and nitrate-nitrogen concentration of 2.3 mg. L. Atyidae, Corbiculidae, Thiaridae, Acari, Baetidae and Leptohyphidae can be considered indicator taxa, showing shifts in the community. This study suggests that values of conductivity and nitrate-nitrogen concentrations should not exceed the threshold levels in order to protect macroinvertebrate biodiversity in the Portoviejo River
Changes in the silver fir forest vegetation 50 years after cessation of active management
Knowledge of the vegetation and the monitoring of its changes in preserved areas is an essential part of effective conservation
policy and management. The aim of this study was to assess the effectiveness of traditional methods of conservation
of silver fir forests. The study analyses the changes in the structure and species composition of a temperate forest excluded
from the commercial silvicultural management for 50 years, and since then protected as a nature reserve. The study is
based on a comparative analysis of phytosociological reléves made on permanent plots in 1961, 1982, 1994 and 2011. PCA
and ecological indicator values were analyzed, as well as characteristic species based on an indicator value (IndVal) index.
Results revealed significant and dynamic changes in the forest structure and composition. The mixed coniferous-broadleaved
forest with Abies alba and diverse ground flora, considered in the 1960s as valuable and worthy of conservation, was found
to have been anthropogenically transformed and unstable. Significant reduction in the human impact was followed by
spontaneous regeneration of oak–hornbeam forest. However, the directional process of changes in vegetation was modified
by such silvicultural treatments as selective cutting of trees and gap creation, all intended for silver fir maintenance. The
results show that Carpinus betulus effectively outcompeted Pinus sylvestris, Picea abies, Quercus robur and A. alba. Changes
in the forest overstory and understory caused temporal changes in the habitat conditions reflected in changes in the ground
vegetation composition. The proportion of light-demanding and oligotrophic species significantly decreased, while the
contribution of species with a wide ecological amplitude, i.e. more shade-tolerant and nutrient-demanding – increased.
The share of A. alba was reduced. Species defined in this study as most valuable, should be actively protected, or selection
of conservation targets should be re-evaluated
The NIOO-approach as evaluation method of the benthic ecological quality within the Water Framework Directive
The EU Water Framework Directive (WFD) requires development of biological indicators and ecological classification for assessment of the ecological quality status of rivers, lakes, coastal and transitional waters. The NIOO - approach is developed to evaluate the ecological status of benthic invertebrates in coastal and transitional waters. This approach aims to be representative for the important structural and functional characteristics of coastal and estuarine ecosystems. The method uses a set of indicators that take into account the different scales of variability in coastal and transitional waters and evaluate the water body (ecosystem) as a whole and not by evaluating sampling station by sampling station. This approach evaluates the ecological status on three different levels (Escaravage et al., 2004; Ysebaert and Herman, 2004). On the level of the whole ecosystem (e.g. a water body) one can evaluate if the benthic macrofauna fulfils the functional role one might expect given the current ecological circumstances. At this level also integration with other quality measures is most appropriate, and information on the water body can be summarised. On the subsequent level the distribution of habitats (habitat completeness, complexity and presence of certain ecoelements [e.g. mussel banks]) can be evaluated. Finally the biological quality of each distinguished habitat based on benthic macrofauna will be evaluated (within-habitat level), based on four indicators (biomass, density, species richness and species composition changes). These four indicators aim at providing a signal that is capable of showing significant changes/deviations from a certain defined reference state. The indicator results strongly depend on the sampling effort (sediment surface) that is deployed in a habitat and water body. Therefore, the reference values for the indicators were calculated per habitat from permutations executed over increased sampling surfaces. This allows estimating, for any given sampling surface, the reference value that can be expected. The expected reference values for each indicator, based on this randomisation, were determined for each ecological status boundary of the WFD. The ecological status for each indicator is finally determined by classifying the observed assessment value in the right ecological status class, based on their defined reference values. The NIOO - approach uses easily interpretable indicators that are evaluated separately. This allows a transparent assessment method and for any deviation of the overall ecological quality ratio from the reference condition the underlying responsible indicator can be easily traced back and evaluated individually. This tool is currently used by the Netherlands and Belgium to evaluate the ecological status of the benthos, following the requirements of the WFD
Assessment of the ecological status of Maltese coastal waters using the Ecological Evaluation Index (EEI)
Benthic macroalgae are a reliable indicator of the trophic status of coastal waters. Macroalgae are also one of the Biological Quality Elements for the evaluation of ecological quality required by the European Water Framework Directive (WFD, 2000/60/EE). The Ecological Evaluation Index (EEI) described by Orfanidis et al. (2001), a specific biological index for the implementation of the WFD in the Mediterranean, was applied to seven sites around Malta with different degrees of anthropogenic stress and which were therefore expected to have a different ecological status. One aim was to assess if the EEI would discriminate between these sites and another was to investigate whether the annual EEI value remained stable for each site over a two‐year period.peer-reviewe
The use of diatom records to establish reference conditions for UK lakes subject to eutrophication
A knowledge of pre-disturbance conditions is important for setting realistic restoration targets for lakes. For European waters this is now a requirement of the European Council Water Framework Directive where ecological status must be assessed based on the degree to which present day conditions deviate from reference conditions. Here, we employ palaeolimnological techniques, principally inferences of total phosphorus from diatom assemblages (DI-TP) and classification of diatom composition data from the time slice in sediment cores dated to similar to 1850 AD, to define chemical and ecological reference conditions, respectively, for a range of UK lake types. The DI-TP results from 169 sites indicate that reference TP values for low alkalinity lakes are typically 3 m mean depth) generally had lower reference TP concentrations than the shallow sites. A small group of shallow marl lakes had concentrations of similar to 30 mu g L-1. Cluster analysis of diatom composition data from 106 lakes where the key pressure of interest was eutrophication identified three clusters, each associated with particular lake types, suggesting that the typology has ecological relevance, although poor cross matching of the diatom groups and the lake typology at type boundaries highlights the value of a site-specific approach to defining reference conditions. Finally the floristic difference between the reference and present day (surface sample) diatom assemblages of each site was estimated using the squared chord distance dissimilarity coefficient. Only 25 of the 106 lakes experienced insignificant change and the findings indicate that eutrophication has impacted all lake types with > 50% of sites exhibiting significant floristic change. The study illustrates the role of the sediment record in determining both chemical and ecological reference conditions, and assessing deviation from the latter. Whilst restoration targets may require modification in the future to account for climate induced alterations, the long temporal perspective offered by palaeolimnology ensures that such changes are assessed against a sound baseline
Particular aspects of geo-ecologic assessment in geo-eco-socio-economic approach to the development of northern territories
In today’s context, the preservation of territory’s ecosystem, when it becomes involved in the economic turnover, requires preemptive geo-ecological assessment aimed at identifying the extent of its sustainability to expected anthropogenic impact. The analysis of the existing methodological approaches to geo-ecological assessment allows to conclude that they are often standardized and can be equally applied to the various types of territories. The goal of this research study is to develop a methodological approach to the geo- ecological assessment of a territory, which allows to consider the specific character of the northern territories in the Ural region. This article proposes a new methodological approach to geo-ecological assessment that takes into account the specific character of the northern territories in the Ural region and is based on assessing the saturation of the natural resource potential of the territory and the intensity of its restoration after the anthropogenic impact. The approach relies on the principle of scoring assessment of a territory, which can be explained by the large surface areas of the assessed territory and by the fact that these assessments are proposed to take place at the pre-project stage of the development of the territory. Such approach allows to consider the specific aspects of the ecosystem of the territory, namely, its ability for self-restoration and self-cleaning during and after the economic development which, in turn, allows to make a general selection of the area of economic activity while minimizing the damage caused by violating the ecosystem of the territory and preserving its resource potential. This article is intended for the specialists and students dealing with the issues of geo-ecological assessment of a territory.This article has been prepared under Grant No. 14–18–00456 Substantiating the Geo-Eco-Socio-Economic Approach to the Development of Strategic Natural Resource Potential of Northern Understudied Territories as Part of the Investment Project The Arctic—Central Asia provided by the Russian Science Foundation
A Study on Green Economy Indicators and Modeling: Russian Context
This article aims to assess and forecast the dynamics of a regional green economy. The research relevance is determined by the need to develop theoretical and methodological basis of the green economy for the transition period and to identify criteria basis for assessing the state and regional level of it. The authors applied the modern methods, which allowed to model criteria considering data uncertainty and both static and dynamic criteria. The research process involved the methods of scientific analysis, comparison and synthesis, the theory of fuzzy sets, and fuzzy modeling. The main principles and methodology of the criteria evaluation for a regional green economy are proposed. The principal methodological approach in this research combines the current state and dynamics of the green economy in evaluating and forecasting the conditions of data uncertainty. The research results form a theoretical, methodological, and practical basis for assessing the current state and level of a regional green economy development, determining the effectiveness of environmental and economic programs, optimizing financial management, conducting environmental monitoring, and developing state plans.The research was funded by the grant of the Ministry of Education and Science of the Russian Federation to Perm National Research Polytechnic University # 26.6884.2017/8.9 "Sustainable development of urban areas and the improvement of the human environment.
- …
