Allotopic Distribution of Native Frogs and Introduced Fishes in High Sierra Nevada Lakes of California: Implication of the Negative Effect of Fish Introductions

Copeia ◽  
1989 ◽  
Vol 1989 (3) ◽  
pp. 775 ◽  
Author(s):  
David F. Bradford
1998 ◽  
Vol 55 (11) ◽  
pp. 2478-2491 ◽  
Author(s):  
David F Bradford ◽  
Scott D Cooper ◽  
Thomas M Jenkins, Jr. ◽  
Kim Kratz ◽  
Orlando Sarnelle ◽  
...  

In an alpine area of the Sierra Nevada of California, naturally acidic waters and introduced fishes both strongly affect the distributions of native amphibians, zooplankton, and macroinvertebrates. The study area in Kings Canyon National Park contains 104 lakes with pH values between 5.0 and 9.3, including 10 lakes with pH < 6.0 (defined here as acidic lakes) and 18 lakes with introduced trout. We surveyed 33 of these lakes (8 acidic, 7 non-acidic with trout, 18 non-acidic without trout) for water chemistry and faunal assemblages. Yellow-legged frog tadpoles (Rana muscosa), common microcrustaceans (Daphnia, Hesperodiaptomus, Diaptomus), and larvae of a caddisfly (Hesperophylax) were rare or absent in acidic lakes but common in non-acidic lakes, and microcrustacean and macroinvertebrate species richness decreased with decreasing pH. Large and (or) mobile, conspicuous taxa, including tadpoles, large-bodied microcrustaceans (Hesperodiaptomus, Daphnia middendorffiana), and many epibenthic or limnetic macroinvertebrates (baetid and siphlonurid mayfly nymphs, notonectids, corixids, limnephilid caddis larvae, and dytiscid beetles), were rare or absent in trout lakes but were relatively common in lakes lacking trout, and the taxon richness of macroinvertebrates was reduced by trout.


Geosciences ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 437
Author(s):  
Tomás R. Bolaño-Ortiz ◽  
Viverlys L. Diaz-Gutiérrez ◽  
Yiniva Camargo-Caicedo

Snow albedo is an important variable in the coupled atmosphere-earth system at the global level. Moreover, studying its behavior allows us to know the state of the cryosphere. The Sierra Nevada de Santa Marta (SNSM) is a glacier area and the northernmost tropical (10.82° N, 73.75° W) region in South America. It has a height of up to 5775 m.a.sl., which is the second highest mountain in the world near the marine coast. We analyzed variations in snow albedo related to snow cover, snowfall, temperature, light-absorbing impurities such as blank carbon (BC), organic carbon (OC) and dust, and El Niño—Southern Oscillation (ENSO) phenomenon through 20 years (2000–2020). We mainly use daily data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra and Aqua NASA satellites. Results showed through correlations that snow albedo has decreased due to Land Surface Temperature (55%, p < 0.001), a positive phase of ENSO (42%, p < 0.001) and dust (37%, p < 0.01) in the SNSM. Additionally, a dust negative effect was more evident on the southern side (up to 49%, p < 0.001) of the SNSM. Backward trajectories by the NOAA HYSPLIT model suggest that dust sources would be soil erosion in the surrounding region. Results can help recognize the influence of ENSO and dust in the glacier decrease of the SNSM.


1990 ◽  
Vol 68 (5) ◽  
pp. 1053-1057 ◽  
Author(s):  
Moira M. Ferguson

The introduction of nonnative fishes or "exotics" and transplants of fishes outside their geographic range but within the same country is a contentious issue. The effects of these introductions on native fish faunas are well documented and have resulted in legislation controlling future introductions of alien species and management policies based largely on living with past mistakes. However, fish introductions also occur at two more subtle levels: transfers within the range of the species, and introduction of foreign DNA to produce "transgenics." The rationale for transfers is largely typological in that "a fish is a fish," at least as far as any given species might be concerned. Transfers disregard the concept that species are divided into genetically distinct units or "stocks" adapted to their particular environment and that introduction of nonlocal conspecifics can disrupt the genetics and adaptation of local populations. This paper raises some of the major issues and the need to synthesize the concepts, documented cases, and effects.


2017 ◽  
Vol 76 (4) ◽  
pp. 145-153 ◽  
Author(s):  
Jana Nikitin ◽  
Alexandra M. Freund

Abstract. Establishing new social relationships is important for mastering developmental transitions in young adulthood. In a 2-year longitudinal study with four measurement occasions (T1: n = 245, T2: n = 96, T3: n = 103, T4: n = 85), we investigated the role of social motives in college students’ mastery of the transition of moving out of the parental home, using loneliness as an indicator of poor adjustment to the transition. Students with strong social approach motivation reported stable and low levels of loneliness. In contrast, students with strong social avoidance motivation reported high levels of loneliness. However, this effect dissipated relatively quickly as most of the young adults adapted to the transition over a period of several weeks. The present study also provides evidence for an interaction between social approach and social avoidance motives: Social approach motives buffered the negative effect on social well-being of social avoidance motives. These results illustrate the importance of social approach and social avoidance motives and their interplay during developmental transitions.


2014 ◽  
Vol 73 (3) ◽  
pp. 135-141 ◽  
Author(s):  
Monica S. Bachmann ◽  
Hansjörg Znoj ◽  
Katja Haemmerli

Emerging adulthood is a time of instability. This longitudinal study investigated the relationship between mental health and need satisfaction among emerging adults over a period of five years and focused on gender-specific differences. Two possible causal models were examined: (1) the mental health model, which predicts that incongruence is due to the presence of impaired mental health at an earlier point in time; (2) the consistency model, which predicts that impaired mental health is due to a higher level of incongruence reported at an earlier point in time. Emerging adults (N = 1,017) aged 18–24 completed computer-assisted telephone interviews in 2003 (T1), 2005 (T2), and 2008 (T3). The results indicate that better mental health at T1 predicts a lower level of incongruence two years later (T2), when prior level of incongruence is controlled for. The same cross-lagged effect is shown for T3. However, the cross-lagged paths from incongruence to mental health are marginally associated when prior mental health is controlled for. No gender differences were found in the cross-lagged model. The results support the mental health model and show that incongruence does not have a long-lasting negative effect on mental health. The results highlight the importance of identifying emerging adults with poor mental health early to provide support regarding need satisfaction.


2013 ◽  
Vol 34 (3) ◽  
pp. 159-169 ◽  
Author(s):  
Sevtap Cinan ◽  
Aslı Doğan

This research is new in its attempt to take future time orientation, morningness orientation, and prospective memory as measures of mental prospection, and to examine a three-factor model that assumes working memory, mental prospection, and cognitive insight are independent but related higher-order cognitive constructs by using confirmatory factor analysis (CFA). The three-factor model produced a good fit to the data. An alternative one-factor model was tested and rejected. The results suggest that working memory and cognitive insight are distinguishable, related constructs, and that both are distinct from, but negatively associated with, mental prospection. In addition, structural equation modeling (SEM) showed that working memory had a strong positive effect on cognitive insight and a moderate negative effect on mental prospection.


2011 ◽  
Author(s):  
Daniel Peterson ◽  
Knox College ◽  
Neil W. Mulligan
Keyword(s):  

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