scholarly journals Long term changes in life history traits and catches of the round sardinella, Sardinella aurita (Clupeidae), along the Senegal coast, West Africa

2021 ◽  
Vol 42 ◽  
pp. 101621
Author(s):  
Ousseynou Samba ◽  
Khady Diouf ◽  
Massal Fall ◽  
Papa Ndiaye ◽  
Jacques Panfili
2017 ◽  
Author(s):  
Lalita Putchim ◽  
Niphon Phongsuwan ◽  
Chaimongkol Yaemarunpattana ◽  
Nalinee Thongtham ◽  
Claudio Richter

The bleaching susceptibility of 28 coral taxa around southern Phuket was examined in four natural major bleaching events, in 1991, 1995, 2010, and 2016. Surveys were conducted by line intercept and belt transect methods. All coral colonies were identified to genus or species-level and their pigmentation status was assessed as: (1) fully pigmented (i.e. no bleaching), (2) pale (loss of colour), (3) fully bleached, and (4) recently dead as a result of bleaching-induced mortality. Bleaching and mortality indices were calculated to compare bleaching susceptibility among coral taxa. In 2016 some of the formerly bleaching susceptible coral taxa (e.g. Acropora, Montipora, Echinopora, and Pocillopora damicornis) showed far greater tolerance to elevated sea water temperature than in previous years. In P. damicornis the higher bleaching resistance encompassed all sizes from juveniles (<5cm) to adults (>30cm). In contrast, some of the formerly bleaching-resistant corals (e.g. the massive Porites, Goniastrea, Dipsastraea, and Favites) became more susceptible to bleaching over repeated thermal stress events. Our results support the hypothesis that some of the fast-growing branching corals (Acropora, Montipora, and Pocillopora) may have life-history traits that lead to more rapid adaptation to a changed environment than certain growing massive species.


Oecologia ◽  
2008 ◽  
Vol 159 (2) ◽  
pp. 463-472 ◽  
Author(s):  
Teddy Albert Wilkin ◽  
Andrew G. Gosler ◽  
Dany Garant ◽  
S. James Reynolds ◽  
Ben C. Sheldon

2007 ◽  
Vol 13 ◽  
pp. 333-336
Author(s):  
S.A. Härri ◽  
J. Krauss ◽  
C.B. Müller

Plant-endophyte associations can have major impacts on the dynamics of consumer interaction-webs but long-term effects of mycotoxins and the ability of herbivores to adapt to these toxins have not been studied. To understand the potential of aphids to cope with mycotoxins, we compared the life-history parameters for aphids conditioned for several generations on endophyte-infected plants with those of endophyte-naïve aphids on both endophyteinfected and endophyte-free grasses. Aphids conditioned on endophyte-infected plants produced more offspring during the first days of adulthood than endophyte-naïve aphids independent of the endophyte infection of the test environment. However, the endophyte-conditioned aphids tended to have a shorter lifespan, which resulted in similar numbers of total offspring produced for endophyte-conditioned and endophyte-naïve aphids. The difference in life-history parameters caused by the conditioning environment suggests that the effects of endophytes on herbivore life-history traits may represent an adaptive change that should be considered in future studies of endophyte-herbivore interactions. Keywords: Rhopalosiphum padi, Neotyphodium lolii, Lolium perenne, common strain, adaptation, long-term effects, microbes, endosymbionts, reproductive strategy, life-history traits


2021 ◽  
Vol 376 (1823) ◽  
pp. 20190745
Author(s):  
Svenja B. Kroeger ◽  
Daniel T. Blumstein ◽  
Julien G. A. Martin

Studies in natural populations are essential to understand the evolutionary ecology of senescence and terminal allocation. While there are an increasing number of studies investigating late-life variation in different life-history traits of wild populations, little is known about these patterns in social behaviour. We used long-term individual based data on yellow-bellied marmots (Marmota flaviventer) to quantify how affiliative social behaviours and different life-history traits vary with age and in the last year of life, and how patterns compare between the two. We found that some social behaviours and all life-history traits varied with age, whereas terminal last year of life effects were only observed in life-history traits. Our results imply that affiliative social behaviours do not act as a mechanism to adjust allocation among traits when close to death, and highlight the importance of adopting an integrative approach, studying late-life variation and senescence across multiple different traits, to allow the identification of potential trade-offs.This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’


Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 839
Author(s):  
Becky K. Kerns ◽  
Michelle A. Day ◽  
Dana Ikeda

Conifer removal in interior woodland ecosystems of the western US is a common management treatment used to decrease fire hazard and shift woodlands to more historical states. Woody material is frequently removed by skidding material off site and via slash pile burning. Assessing the long-term outcomes of seeding treatments after such ground disturbing activities is critical for informing future management and treatment strategies. Using two designed experiments from a central Oregon juniper woodland, we resampled slash piles and skid trails 8 years after seeding. Our objectives were to assess the long-term vegetation response to conifer removal, ground disturbance, and seeding source (cultivar and local) in slash piles and skid trails. We found that seeded species persisted in the long term, but abundance patterns depended on the species, seed source, and the type of disturbance. In general, there were more robust patterns of persistence after pile burning compared to skid trails. Seeding also suppressed exotic grass cover in the long term, particularly for the local seed source. However, the invasion levels we report are still problematic and may have impacts on biodiversity, forage and fire behavior. Our short-term results were not predictive of longer-term outcomes, but short- and long-term patterns were somewhat predictable based on species life history traits and ecological succession. The use of a mix of species with different life history traits may contribute to seeding success in terms of exotic grass suppression. Lastly, our results suggest that locally adapted seed sources may perform as well or better compared to cultivars. However, more aggressive weed treatments before and after conifer removal activities and wider seeding application may be needed to effectively treat exotic grass populations.


2016 ◽  
Vol 172 ◽  
pp. 56-66 ◽  
Author(s):  
Ilaria Bernabò ◽  
Antonello Guardia ◽  
Rachele Macirella ◽  
Settimio Sesti ◽  
Antonio Crescente ◽  
...  

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