Consulta: subjectFacets:"Population parameters"
Registros recuperados: 7
Data/hora: 13/06/2024 03:32:14

Population ecology of Eligmodontia morgani (Rodentia, Cricetidae, Sigmodontinae) in northwestern Patagonia
Provedor de dados: 67
Autores: Monteverde,Martín; Piudo,Luciana; Hodara,Karina; Douglass,Richard.
Eligmodontia morgani is one of the most abundant endemic species of arid Patagonian steppe. Most previous studies have focused on systematics and taxonomy and ecological information on this species is scarce. The objectives of this study were to estimate population parameters for E. morgani in the Patagonian steppe ecoregion and to compare them to parameters available for this species in another environment. Data were collected from February 2003 through October 2004. Abundances ranged from 12±1.85 to 71±6.67, with residents comprising 39% of the population. The sex ratio was female biased and age classes resulted in juveniles body mass &amp;#8804;11 g, subadults between 13-15 g, and adults &amp;#8805;17g. The breeding season lasted from August to March....
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Patagonian steppe ecoregion; Arid environments; Silky desert mouse; Rodent ecology; Population parameters.
Ano: 2011
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2011000200007

Cystoseira baccata meadows along the French Basque coast (Bay of Biscay) as a reference for the implementation of the Water Framework and Marine Strategy EU directives
Provedor de dados: 5
Autores: De Casamajor, Marie-noelle; Derrien-courtel, Sandrine; Lalanne, Yann; Maria Gorostiaga, José; Le Gal, Aodren; Huguenin, Laura; Quintano, Endika; Lissardy, Muriel.
Cystoseira baccata, a biological quality element for the implementation of the Water Framework and Marine Strategy EU Directives, is a dominant species in the subtidal rocky bottoms of the Basque coast. As part of this issue and given the need to better understand the functional character of benthic rocky ecosystems and use them as a reference to anthropogenic changes, two samplings campaigns were conducted in 2014 and 2017. Several population parameters (i.e. frond density, frond length frond-length/total frond-length ratio and taxonomic richness of epibionts) of C. baccata were studied from three sites monitored within the Water Directive Framework in relation to bathymetry during the two campaigns. The results showed a significant influence of...
Tipo: Text
Palavras-chave: Bathymetry; Cystoseira baccata; Epiphytes; Foundation species; Population parameters; Water framework directive.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00500/61151/64581.pdf

Wide reproductive period of a long-distance migratory fish in a subtropical river, Brazil
Provedor de dados: 83
Autores: Zaniboni-Filho,Evoy; Ribolli,Josiane; Hermes-Silva,Samara; Nuñer,Alex P. O.
ABSTRACT Salminus brasiliensis is a potamodromous fish species that occurs in southern South American rivers. In spite of its ecological and economic relevance, information regarding the reproductive biology of S. brasiliensis is still scarce. This study used data from 18 years of continuous sampling in the Upper Uruguay River Basin, analyzing 718 adult fish (307 males, 243 females, 168 undefined) captured at different months of the year. The results showed that the reproductive timing for S. brasiliensis is wide in the Upper Uruguay River, with the occurrence of mature fish between the month of August and March and spawned individuals between July and May of the next year. These results were sustained by the increase of gonadal somatic relationship (GSR)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dourado; Long-term study; Population parameters; Salminus brasiliensis; Uruguay River.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000100215

Growth of the Cichla temensis Humboldt, 1821 (Perciformes: Cichlidae) from the middle rio Negro, Amazonas, Brazil
Provedor de dados: 83
Autores: Campos,Caroline Pereira; Freitas,Carlos Edwar de Carvalho; Amadio,Sidineia.
This study aimed to estimate age and growth of the peacock bass Cichla temensis from the rio Negro (Brazilian Amazonia) by analyzing scale annuli. Specimens were captured between October 2011 and September 2012 in the main channel of the river and in adjacent lakes in the municipality of Barcelos, AM, Brazil. Six growth checks were identified on the scales of specimens. The annual variation in body condition observed suggests that fat is accumulated during the dry season. Results for the GSI (gonadosomatic index) showed that peak reproduction occurred in the receding-water period, indicating that the fish had energy deficiencies as a result of reproductive activity. RMI (relative marginal increment) analysis revealed that an annulus is formed once a year...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Age; Hydrological period; Peacock bass; Population parameters; Scales.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200413

When &lt;i&gt;m&lt;/i&gt;-selection?
Provedor de dados: 27
Autores: Bergmans, M.
Caswell and Hastings (1980) introduced an explicit model for the relative merits, in terms of growth rate &lt;i&gt;lambda&lt;/i&gt;, of developmental shifts vs. fecundity increases. Some aspects of their model are clarified by concentrating on the (fitness &gt;1) half-plane rather than on the (accelerated reproduction) half-plane. There is no strict equivalence between Caswell and Hastings' key parameter &lt;i&gt;lambda/P&lt;/i&gt; and the dynamic behaviour of the population which is governed by &lt;i&gt;lambda&lt;/i&gt;. Thus in some stationary/declining populations time shifts of reproduction (forward or backward, according to the value of &lt;i&gt;lambda/P&lt;/i&gt;) are just as effective in promoting a high &lt;i&gt;lambda&lt;/i&gt; as they are in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Population parameters.
Ano: 1983
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3364

Life table of Hypothenemus hampei (Ferrari) in relation to coffee berry phenology under Colombian field conditions
Provedor de dados: 63
Autores: Ruiz-Cárdenas,Ramiro; Baker,Peter.
The overlap of generations of coffee berry borer (CBB), Hypothenemus hampei (Ferrari) under field conditions in countries like Colombia hinders the construction of life tables by the sampling of natural populations. In this paper, a field methodology to carry out regular measurements of CBB cohorts inside coffee berries of different ages until harvest, both in coffee trees and in infested berries placed on the ground, is developed and used to compare the life history parameters of CBB. Populations with berries at six ages in three experimental stations (without CBB control) and in a commercial farm in Colombia (with chemical CBB control regularly carried out) were used. The duration of the pre-oviposition period as well as the mortality and survival rates...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee berry borer; Population parameters; Integrated pest management.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000600007

Population dynamics of Pseudevadne tergestina (Branchiopoda: Onychopoda) in Guanabara Bay, Brazil
Provedor de dados: 52
Autores: Marazzo,Andrea; Valentin,Jean Louis.
Populations of Pseudevadne tergestina were studied in Guanabara Bay, southeastern Brazil, to assess temporal variations in density and population dynamics. Data on temperature, salinity and zooplankton samples were taken from the superficial water of a fixed station, every 3 - 4 days, from February 2 through August 1, 2000. The highest abundance of this species was observed in March, when densities varied widely, from 20 to 600 ind. m-3. Population parameters were calculated, such as birth rate (from 0.25 to 0.90 ind.-1.day-1), growth rate (from -1.30 to 2.09 day-1 ) and death rate ( from -1.6 to 1.9 day-1 ) Start of population could be attributed to the increase of temperature and to the hatching of resting eggs. The population collapsed in fall-winter,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zooplankton; Cladocera; Population parameters; Temporal distribution; Guanabara bay; Brazil.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000500006