Ecology

Does grazing change algal communities from grassland and pine afforested streams?: A laboratory approach
Drastic changes in the composition and physiognomy of riparian vegetation, such as the conversion of grassland to forest, are expected to alter interactions among light availability, primary producers and herbivores. Our aim was to examine in laboratory the influence of a ubiquitous grazer on periphyton grown in a grassland unshaded stream (reference) vs. periphyton from a nearby pine afforeste...


Influence of stock origin and environmental conditions on the survival and growth of juvenile freshwater pearl mussels (Margaritifera margaritifera) in a cross-exposure experiment
The freshwater pearl mussel (Margaritifera margaritifera) is a highly specialized and sensitive freshwater bivalve, whose survival in the juvenile phase is indicative of high quality habitats. This contribution investigates the use of juvenile freshwater pearl mussels as bioindicators, considering the influence of mussel stock and study stream conditions on juvenile performance, as described by...
River bed stability versus clogged interstitial: Depth-dependent accumulation of substances in freshwater pearl mussel (Margaritifera margaritifera L.) habitats in Austrian streams as a function of hydromorphological parameters
Substrate conditions are considered crucial for the survival of juvenile freshwater pearl mussels (Margaritifera margaritifera L.)–and therefore for the recovery of overaged populations in danger of extinction–as fine sediments can clog the interstitial habitat and hamper water and oxygen circulation to the juveniles. Watercourses and their bed sediments must meet two seemingly diametricall...


Conservation status of the freshwater pearl mussel Margaritifera margaritifera in Portugal
Based on new information, the current conservation status of the freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) in Portugal is revised. Between 2010 and 2013 surveys were conducted in eight different rivers to assess distribution, abundance, size-frequency and preferential habitat of this species. Rivers Neiva, Cávado and Terva presented very low abundances (in the Cávad...
Genetic diversity and population structure of Schizopygopsis younghusbandi Regan in the Yarlung Tsangpo River inferred from mitochondrial DNA sequence analysis
The genetic diversity and population structure of Schizopygopsis younghusbandi from six sites in the middle reach of the Yarlung Tsangpo River were examined based on mitochondrial DNA cytochrome b (Cyt b) gene and control region (D-loop) sequences. 1141 bp of complete Cyt b sequences and 737 bp of partial D-loop sequences for 153 individuals of S. younghusbandi were obtained by using PCR ampl...


Effect of P-Reactive Drainage Aggregates on Green Roof Runoff Quality
The main hypothesis of the presented study is that the negative effect of phosphorus leaching from a green roof substrate can be reduced by including P-reactive material in a drainage layer. In this work, different aggregates (Pollytag®, lightweight expanded clay aggregates, chalcedony, serpentynite and crushed autoclaved aerated concrete) to be used as the green roof drainage layer are descri...
Integrated Water Resource Management and Energy Requirements for Water Supply in the Copiapó River Basin, Chile
Population and industry growth in dry climates are fully tied to significant increase in water and energy demands. Because water affects many economic, social and environmental aspects, an interdisciplinary approach is needed to solve current and future water scarcity problems, and to minimize energy requirements in water production. Such a task requires integrated water modeling tools able to ...

Assessing the Effects of Periodic Flooding on the Population Structure and Recruitment Rates of Riparian Tree Forests
Riparian forest stands are subjected to a variety of hydrological stresses as a result of annual fluctuations in water levels during the growing season. Spring floods create additional water-related stress as a result of a major inflow of water that floods riverside land. This exploratory study assesses the impacts of successive floods on tree dynamics and regeneration in an active sedimentatio...
Coral reef organisms as bioregion indicators off Halmahera, Moluccas, Indonesia
In the planning of marine protected areas for the conservation of coral reef systems, it is important to be able to distinguish between certain bioregions, i.e. regions with distinct species assemblages. This was done off western Halmahera (Moluccas, Indonesia), where three such bioregions were distinguished based on species inventories of 41 coral reef sites. The relative value of species belo...

Nitrogen pollution negatively affects Stratiotes aloides in Central-Eastern Europe. Implications for translocation actions
The preliminary evaluation of threats and the possibility of their removal or mitigation is a key issue for a successful translocation. Here, the possibility to reintroduce Stratiotes aloides in Italy where it had become extinct about 25 years ago was investigated by studying the difference in water quality in sites where the species currently exists in Europe, where the species has recently ...
Variability in potential to exploit different soil organic phosphorus compounds among tropical montane tree species
We hypothesized that tropical plant species with different mycorrhizal associations reduce competition for soil phosphorus (P) by specializing to exploit different soil organic P compounds. We assayed the activity of root/mycorrhizal phosphatase enzymes of four tree species with contrasting root symbiotic relationships–arbuscular mycorrhizal (angiosperm and conifer), ectomycorrhizal and non-m...

Patterns of Mortality and Factors Influencing Survival of a Recently Restored Elk Population in Ontario, Canada
This study examined patterns of mortality and determinants of survival among elk recently restored to four sites in Ontario, Canada (1998–2005). We predicted that: (1) elk located in release sites closer to the core of their historic range would have higher survival; survival would increase as an animal's time and experience on the landscape increased; and survival rates would decline as anim...
Development of a Spatially Universal Framework for Classifying Stream Assemblages with Application to Conservation Planning for Great Lakes Lotic Fish Communities
Classifications are typically specific to particular issues or areas, leading to patchworks of subjectively defined spatial units. Stream conservation is hindered by the lack of a universal habitat classification system and would benefit from an independent hydrology-guided spatial framework of units encompassing all aquatic habitats at multiple spatial scales within large regions. We present a...
People and pixels in the Sahel: a study linking coarse-resolution remote sensing observations to land users? perceptions of their changing environment in Senegal
Mounting evidence from satellite observations of a re-greening across much of the Sahel and Sudan zones over the past three decades has raised questions about the extent and reversibility of desertification. Historical ground data that could help in interpreting the re-greening are scarce. To fill that void, we tapped into the collective memories of local land users from central and western Sen...
Exploring agency beyond humans: the compatibility of Actor-Network Theory (ANT) and resilience thinking
At first glance, the compatibility of social theory and resilience thinking is not entirely evident, in part because the ontology of the former is rooted in social interactions among human beings rather than ecological process. Despite this difference, resilience thinking engages with particular aspects of social organization that have generated intense debates within social science, namely the...