Ecological Integrity Of Rivers Research Articles

Overcoming Resource Nexus Conflicts With a Normative-Institutional Approach: A Case Study of Brazil

Water-energy nexus research highlights the need for co-management across water and energy sectors, whereby joint planning and solutions under better integrated governance of resources could make action more efficient and cost-effective to advance the SDGs. A gap remains in the literature with regards to the normative dimension of the resource nexus. At the background or resource nexus conflicts there are norms, which need to be considered and applied in the resolution of disputes. Brazil has been chosen as case study because of rising conflicts around its high dependency on water and hydropower generation to keep affordable tariffs, while securing multiple water uses. Hydrological factors (e.g., prolonged droughts) and non-hydrological factors (e.g., chronic delays in delivery of new plants and transmission lines) have impacted on water availability, which led to constraints for hydropower generation, with cascading economic, social and environmental impacts. Electricity prices have risen, while water quantity and quality have decreased, affecting multiple users and ecological integrity of rivers. All of which impact negatively on livelihoods and water services and sanitation, aggravated by the fact that electricity represents one of the fastest growing costs for Water services, Sanitation and Hygiene (WASH) suppliers. The novel combination of research methods based on metrics, historical-institutional analysis, questionnaire, and in-depth interviews served as instruments for the assessment of the water-electricity nexus issues and development of a new legal approach to manage conflicts arising in Brazil. Most of the existing work has favored integration of water and electricity sectors based on quantitative approach to address the interlinkages between them and tackle trade-offs. However, from a legal perspective, very little is known about how these sectors could be better integrated in practice. This study proposes a normative-institutional approach that offers a flexible, integrated, and adequate legal treatment to overcome the conflicts between water and electricity in the context of their asymmetrical governance, policies, regulation, planning and environmental injustices. Split in substantive, institutional, and procedural dimensions this approach is necessary to enhance participatory and equitable resource governance based on the laws of balancing legal principles, rational, inclusive, and transparent procedures. It was concluded that for water-electricity nexus thinking to be connected to the idea of integration it will be necessary to consider justice by taking a normative-institutional approach that can support advances to the SDGs in more holistic and fair ways.

Assessment of river health based on an improved entropy-based fuzzy matter-element model in the Taihu Plain, China

Rivers are valuable to human beings because of their various functions. Unfortunately, ecological integrity of rivers has been seriously threatened by human activities, resulting in poor river functions. It is thus necessary to evaluate and maintain river health. Meanwhile, it is challenging to comprehensively assess river health with a single method alone. It is therefore relevant to combine the advantages of multiple methods in river health assessment. By classifying and characterizing river functions, we first established an indicator system for river health assessment in plain river network regions. We then assessed the health status of the Taihu Plain in terms of an improved entropy-based fuzzy matter-element model. We found that the overall health status of the Taihu Plain is below “good”. In particular, the health status of Yang-Cheng-Dian-Mao and Hang-Jia-Hu Region is “moderate”; the Wu-Cheng-Xi-Yu Region displays the poorest natural and social river functions. We also found that flood control is the most important influential factor in river health. Our findings suggest that rivers in the Taihu Plain must be restored to maintain their health, with the Wu-Cheng-Xi-Yu Region that must be restored preferentially, and that the river function of flood control must be improved at the scale of whole watershed. Comparing with other four commonly used comprehensive assessment methods, our improved entropy-based fuzzy matter-element model outperforms in reflecting objective fact and can be applied to river health assessment. Our results are generally consistent with existing studies, confirming that the proposed method for river health assessment is effective and feasible. Therefore, it provides a useful reference for river health assessment in other plain river network regions.

Amplified fragment length polymorphism analysis reveals high genetic variation in the Ouachita Mountain endemic Carex latebracteata (Cyperaceae)

Species with limited geographic ranges are often of conservation concern because they may possess low levels of genetic variability and thus have a reduced ability to respond to stochastic events. As a consequence, an important conservation strategy is to maximize a species’ adaptive potential by preserving natural levels of genetic variation. With this goal in mind, we assessed genetic variation within and among six populations of the Ouachita Mountain endemic Carex latebracteata Waterfall using 653 amplified fragment length polymorphism (AFLP) loci. Indices of genetic variation [% polymorphic loci, expected heterozygosity (HE), population differentiation (ΦPT)] were most consistent with an outcrossing or mixed mating system despite an inflorescence morphology that seems conducive to self-pollination. An analysis of molecular variance (AMOVA) showed that >80% of the variation occurred within populations, suggesting high levels of gene flow. The close geographic proximity of most populations, which are often adjacent to streams, may facilitate long-distance seed dispersal and help to maintain high intra-population genetic variation. Conservation strategies focused on maintaining the ecological integrity of rivers and streams, and the provision of naturally vegetated buffers would likely assist in the conservation of this and other Ouachita Mountain endemics.

Conservation importance of semi‐arid streams in north‐eastern Brazil: implications of hydrological disturbance and species diversity

1. Intermittent streams in the semi-arid region of Brazil are distinctive landscape features existing as dry watercourses for most of the time. It has been recognized that the extremes of flooding and total absence of water flow are the principal hydrological characteristics of rivers and streams in this region. This is a consequence of complex climatic patterns that lead to an irregular distribution of the small amount of rainfall and low thermal amplitude. The latter is the main climatic difference between the Brazilian semi-arid region and other semi-arid lands. 2. The expansion of water resource development has been a threat to the natural flow regime and the ecological integrity of rivers and streams in semi-arid Brazil. Efforts to manage and conserve the natural flow regime of these systems are hampered by limited scientific information on the ecological processes driving their flora and fauna and the responses of biota to the high natural variability in flow regime. 3. The most important issues in the conservation of streams in semi-arid Brazil are the need for their recognition as important sites of biodiversity and that this diversity is closely associated with natural patterns of flow and the hydrological disturbances. Without the understanding of how the extremes of flooding and drought affect the aquatic fauna, the conservation strategies for Brazilian semi-arid streams and their fauna will not be effective. 4. Therefore, conservation efforts in semi-arid Brazil must ensure that the processes sustaining biodiversity are maintained at multiple-scale and landscape levels and that the natural integrity of the riparian zone is maintained Copyright © 2006 John Wiley & Sons, Ltd.

Ecological integrity of river–floodplain systems—assessment by dragonfly surveys (Insecta: Odonata)

Ecological integrity of river–floodplain systems—assessment by dragonfly surveys (Insecta: Odonata)