scholarly journals Recovery of freshwater invertebrates in alpine lakes and streams following eradication of nonnative trout with rotenone

Author(s):  
Mark E. Schnee ◽  
Niall G. Clancy ◽  
Matthew C. Boyer ◽  
Samuel Leonard Bourret

Nonnative fish eradication via the piscicide rotenone is an effective tool for fisheries management and conservation of native species. However, the long-term effects on non-target organisms, including benthic invertebrates and zooplankton in alpine lakes, are under-studied and are poorly understood. As part of a landscape-scale native fish conservation project, we assessed the effects of 50 ppb rotenone on the aquatic invertebrate community by comparing pre- and post-rotenone treatment density and diversity metrics of benthic invertebrates and zooplankton in 13 alpine lakes and their outlets in Montana, USA. Across study sites, decreases in density and diversity of some invertebrates, including Ephemeroptera, Plecoptera, and Trichoptera taxa, were observed the year following rotenone treatment, and within three years, densities and diversities were similar to and sometimes higher than pre-treatment values. These results demonstrate resilience of aquatic invertebrate communities following rotenone exposure in alpine lakes and streams and informs fisheries managers for planning rotenone projects and monitoring recovery of non-target organisms. Further studies will be useful to evaluate the mechanisms driving invertebrate recovery rates, including downstream drift from nontreated areas and terrestrial adult dispersal.

2017 ◽  
Vol 24 (2) ◽  
pp. 285-298 ◽  
Author(s):  
Aneta Spyra ◽  
Justyna Kubicka ◽  
Małgorzata Strzelec

AbstractRecognition of the deteriorating conditions of rivers worldwide has called for increased efforts to improve the ecological quality of impacted river systems. This is particularly important in areas that have suffered from a significant impact of human pressure on the ecological status of water. Field studies were conducted in the Ruda River in an area that had undergone anthropogenic disturbances. The objectives of our survey were to test the biological metrics based on benthic macroinvertebrates at four study sites. Spring and autumn surveys of benthic invertebrates indicated that based on the BMWP and BMWP(PL) indices, water quality was higher in comparison with the value of Multimetric index at all of the sites that were studied. Our results revealed that the water quality was higher at the study sites that are located above the dam reservoir based on both the chemical and biological parameters. This study also indicated that both spring and autumn constitute appropriate periods for carrying out monitoring studies. The values of multimeric index indicated the same water quality (except for site 1) in both sampling periods. Anthropogenic transformations of a riverbed influence the flora and fauna and affect the ecological status of rivers.


2018 ◽  
Vol 5 (5) ◽  
pp. 172477 ◽  
Author(s):  
Dailos Hernández-Brito ◽  
Martina Carrete ◽  
Carlos Ibáñez ◽  
Javier Juste ◽  
José L. Tella

The identification of effects of invasive species is challenging owing to their multifaceted impacts on native biota. Negative impacts are most often reflected in individual fitness rather than in population dynamics of native species and are less expected in low-biodiversity habitats, such as urban environments. We report the long-term effects of invasive rose-ringed parakeets on the largest known population of a threatened bat species, the greater noctule, located in an urban park. Both species share preferences for the same tree cavities for breeding. While the number of parakeet nests increased by a factor of 20 in 14 years, the number of trees occupied by noctules declined by 81%. Parakeets occupied most cavities previously used by noctules, and spatial analyses showed that noctules tried to avoid cavities close to parakeets. Parakeets were highly aggressive towards noctules, trying to occupy their cavities, often resulting in noctule death. This led to a dramatic population decline, but also an unusual aggregation of the occupied trees, probably disrupting the complex social behaviour of this bat species. These results indicate a strong impact through site displacement and killing of competitors, and highlight the need for long-term research to identify unexpected impacts that would otherwise be overlooked.


2017 ◽  
pp. 163-171 ◽  
Author(s):  
Enrico Scarici ◽  
Roberto Ruggeri ◽  
Maria Elena Provenzano ◽  
Francesco Rossini

The use of native species in landscape design is a choice related to environmental sustainability and it contributes to the aesthetic appeal of urban and marginal areas. However, to date, the lack of knowledge of the ecological characteristics and agronomic practices of these species, represents a limit for their use. This study aims to obtain information about germination ecology, morphological traits and ornamental value of 7 selected perennial native taxa, with potential use in meadows seed mixtures for the Mediterranean environment. Seed germination for each taxon was assessed under different conditions (temperature, photoperiod and pre-treatment) in a controlled environment, while data on plant performances was collected from field plots. In general, the dormant seeds showed a positive response to pre-treatment with gibberellic acid (GA3) and chilling within a period of about six months from the time of seed collection. The dependence of germination on light and temperature was observed in most of the tested taxa. Differences in plant height and flowering dynamics gave practical directions in terms of combining seeds of different species to create and maintain a wildflower meadow in low-maintenance areas. Crepis bursifolia L. and Hypochaeris radicata L. were the only two species, which showed good persistence during the two-year field study and met the aesthetic requirements of low-input Mediterranean landscaping. Our study by adding original findings to the limited knowledge available on wildflower sowing in the Mediterranean environment, contributes to the development of sustainable strategies in the greening projects designed for those peculiar climatic conditions.


Botany ◽  
2015 ◽  
Vol 93 (11) ◽  
pp. 745-757 ◽  
Author(s):  
Mónica Higuera-Díaz ◽  
Jessamyn S. Manson ◽  
Jocelyn C. Hall

Flowering plants that attract a diverse range of pollinators represent a generalist pollination system. Studying these plants provides valuable information about accessibility of floral resources to pollinators, which is particularly important in areas where scarcity of flowers limits pollinator populations. Here, we describe the flowering phenology, reproductive biology, and visitor community of Cleomella serrulata (Pursh) Roalson & J.C.Hall and Polanisia dodecandra (L.) DC., two native species with generalist pollination systems and limited distribution in Albertan prairies. Although their flowers are similar, they differ in traits such as petal colour, inflorescence size, and nectar display. Both species were facultatively cross-pollinated and exhibited nocturnal anthesis but differed in nectar production patterns. Cleomella serrulata produced highest nectar volume in the morning and highest sugar concentration at noon, while Polanisia dodecandra produced highest nectar volume before noon but sugar concentrations were higher at sunset. We observed 150 insect taxa visiting the plants, with Hymenoptera and Diptera as the most frequent visitors for Cleomella serrulata and Polanisia dodecandra, respectively. We recorded the first nocturnal flower visitors for Cleomella serrulata and the first record of Nysson plagiatus (Cresson) for Alberta. Both plant species present effective nectar and pollen resources for pollinators at the study sites and may be useful in the maintenance of native pollinators in at-risk prairie ecosystems.


2017 ◽  
Vol 35 (5_suppl) ◽  
pp. 133-133
Author(s):  
Aubri Veneruso ◽  
Megan Rae Slocum ◽  
Sheetal Mehta Kircher ◽  
Nausheen Akhter ◽  
Gillian Murtagh ◽  
...  

133 Background: Improvements in early detection, screening, and treatment of cancer translate into survivors living longer, highlighting the need for guidelines to address the late and long-term effects of cancer treatment. A particularly concerning effect is Cancer Therapeutics-Related Cardiac Dysfunction (CTRCD). Cancer treatments can result in a range of cardiovascular toxicity including left ventricular dysfunction, heart failure and radiation-induced heart disease (RIHD). Various consensus statements related to cardiovascular care for adult cancer survivors exist; however there are no globally accepted follow-up guidelines. Our purpose is to create a protocol to stratify a survivor’s cardiac risk and provide a basis for follow-up recommendations. Methods: We first evaluated existing resources within our institution and identified key stakeholders who were recruited to form a multidisciplinary workgroup (2 survivorship advanced practice providers, an oncologist, a radiation oncologist, and 2 cardio-oncologists). We then reviewed current research and literature on cardiotoxic cancer therapies and identified two consensus statements from the American Society of Echocardiography and the European Association of Cardiovascular Imaging which helped inform our protocol. Finally, we created a cardiac assessment that could be applied in the pre-treatment phase and extend into the post-treatment phase. Results: Two assessment tools were developed. The first is an algorithm initiated in the pre-treatment setting by an oncologist when a Type I or Type II cardiotoxic agent is planned. The second is a risk assessment tool that is initiated in the post-treatment setting to stratify cardiac risk and provide follow-up recommendations. Conclusions: Development of standardized guidelines for assessment and treatment of late and long-term effects of treatment is critical. This protocol has been developed to account for the many factors that contribute to overall cardiac risk after various anti-cancer therapies. Further data is needed to evaluate long-term cardiac and survival outcomes based on this protocol.


2018 ◽  
Vol 38 (1) ◽  
pp. 237-246 ◽  
Author(s):  
Lynda M. Fried ◽  
Matthew C. Boyer ◽  
Meriel J. Brooks

1996 ◽  
Vol 47 (6) ◽  
pp. 851 ◽  
Author(s):  
BJ Robson

Densities of benthic invertebrates were counted over several weeks before and after a small winter spate (15.5 times base flow) in two riffle types of contrasting architectural complexity in Mountain River, Tasmania. Complex benthic architecture reduced the impact of this spate on invertebrate densities over the short term (seven days). Longer-term recovery (several weeks) was unaffected by riffle architecture, with one of the riffles recovering much more slowly than the others. Refuges from small spates in Mountain River may exist in mid channel in complex boulder-cobble riffles. Within its temporal context, the effects of the spate on the study sites were of a similar magnitude to other unexplained population fluctuations.


2017 ◽  
Vol 43 ◽  
pp. 28-34 ◽  
Author(s):  
K.W. Müller ◽  
K. Wölfling ◽  
U. Dickenhorst ◽  
M.E. Beutel ◽  
J. Medenwaldt ◽  
...  

AbstractPurpose:Gambling disorder is associated with various adverse effects. While data on the immediate effectiveness of treatment programs are available, follow-up studies examining long-term effects are scarce and factors contributing to a stable therapy outcome versus relapse are under-researched.Materials and methods:Patients (n = 270) finishing inpatient treatment for gambling disorder regularly participated in a prospective multicenter follow-up study (pre-treatment, post-treatment, 12-month follow-up). Criteria for gambling disorder, psychopathology, functional impairment were defined as endpoints. Changes in personality were defined as an additional parameter.Results:At follow-up, three groups were identified: subjects maintaining full abstinence (41.6%), patients still meeting criteria for gambling disorder (29.2%), and subjects still participating in gambling without meeting the diagnostic criteria for gambling disorder (29.2%). Every group had improvements in functional impairment, abstinent subjects showed the lowest psychopathology. Significant decreases in neuroticism and increases in both extraversion and conscientiousness were found among abstinent subjects but not in patients still meeting criteria for gambling disorder.Discussion:One year after treatment, a considerable percentage of patients kept on gambling but not all of them were classified with gambling disorder leading to the question if abstinence is a necessary goal for every patient.Conclusions:The changes of personality in abstinent patients indicate that after surmounting gambling disorder a subsequent maturing of personality might be a protective factor against relapse.


Soil Systems ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 59
Author(s):  
Peter Rwibasira ◽  
Francois Xavier Naramabuye ◽  
Donat Nsabimana ◽  
Monique Carnol

Understanding the long-term effects of tree species on soil properties is crucial for the development of forest restoration policies in relation to the choice of species that meet both environmental and local livelihood needs. This study was performed in the Arboretum of Ruhande, Southern Rwanda, where monocultures of 148 deciduous and 56 conifer species have been established in 0.25 ha replicated plots from 1933 onwards. We investigated the effects of six exotic and two native tree species planted in monoculture plots and native species mixed within one self-regenerated plot on soil properties in two layers (0–5 cm and 5–10 cm depth). We measured general soil properties (pH, SOM, exchangeable base cations) and water-soluble C and N as a proxy for soil functioning. Changes in soil properties were observed in the upper soil layer for all tree species. Planting Eucalyptus species caused soil acidification, whereas soil exchangeable cations and pH were higher under native species (Entandrophragma excelsum and Polyschias fulva) and mixed native species. The effects of tree species were more pronounced for hot water-extractable C and N than for other soil properties. Their analyses could be used for detecting changes in soil functioning linked to vegetation types.


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