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Occurrence of wide-band tracheids in Cactaceae: wood variation during Pilosocereus auriasetus development

GODOFREDO, Vanessa Romero; MELO-DE-PINNA, Gladys Flavia
Fonte: TORREY BOTANICAL SOC Publicador: TORREY BOTANICAL SOC
Tipo: Artigo de Revista Científica
Português
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Studies of wide-band tracheids (WBTs) have aroused the interest of researchers who have searched to understand their origin, function, and phylogenetic implications. The present research has the objective of studying the distribution of WBTs, together with anatomic aspects of vegetative organs in different stages of Pilosocereus aurisetus, in order to understand the occurrence of WBTs in columnar cacti. Transverse and longitudinal sections of the stem (apex, middle, and base) and the root were made. The epidermis was present in the photosynthetic stem, but was substituted by periderm which was already well established in the root. The differentiation of the cortex is visible in the middle of the stem, becoming homogeneous in the base. WBTs were observed in the base and middle of young stems (WBT monomorphic wood); common in stems of globular cacti. However, WBTs/ fibrous dimorphic wood was observed in the base of adult stems, a result of the cambial activity producing vessel elements and fibers. This wood polymorphism of the Cactaceae can be interpreted as cambial variation, a common character of Caryophyllales. Due to the small size of the plant, the presence of WBTs in the young stem may be related to water retention necessary for its development...

Bactérias associadas às cactáceas da Caatinga: promoção de crescimento de plantas sob estresse hídrico; Cacti-associated bacteria from Caatinga: plant growth promotion under water stress

Kavamura, Vanessa Nessner
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/10/2012 Português
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A Caatinga, bioma exclusivamente brasileiro, inserido no clima semiárido nordestino, apresenta xerófitas com alta resistência aos períodos de seca. Estas plantas associam-se a micro-organismos que também se encontram bem adaptados, desenvolvendo mecanismos de proteção celular contra o estresse hídrico, assim como proteção vegetal contra os efeitos negativos da dessecação. O presente estudo buscou compreender as bactérias associadas às cactáceas da Caatinga, analisando a estrutura das comunidades bacterianas de solo e da rizosfera de Cereus jamacaru durante a alteração do período chuvoso para o de seca, identificando os grupos dominantes e discutindo algumas funções que possibilitem a manutenção da interação solo-cacto-micro-organismo durante o período de seca. Além disso, buscou selecionar bactérias tolerantes à seca e que fossem capazes de promover crescimento de plantas sob estresse hídrico. Amostras foram coletadas ao longo da Caatinga, em cinco estados: BA, CE, PI, PB e RN totalizando cinco pontos. Com o uso de metodologias independentes de cultivo, foi possível observar que o período de amostragem (chuvoso/seca) foi o principal responsável pela alteração na estrutura das comunidades bacterianas. Os filos Proteobacteria e Bacteroidetes foram abundantes durante o período chuvoso e os filos Actinobacteria e o gênero Bacillus abundantes durante o período de seca. Com o uso de metodologias dependentes de cultivo...

Uma proposta de solução de gerenciamento de contabilização utilizando Nagios e Cacti; An accounting management solution with Nagios and Cacti

Koch, Moisés
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
Português
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Esta monografia apresenta uma proposta de solução de gerenciamento para uma rede local de computadores, a partir do gerenciamento de contabilização. Depois de fazer uma breve revisão dos principais tópicos de gerência de redes, o trabalho concentra-se em gerenciamento de contabilização, descrevendo os princípios desta área funcional do gerenciamento e ferramentas. Além disso, também apresenta um estudo de caso com a utilização das ferramentas Nagios e Cacti, bem como uma análise dos resultados obtidos.; This document aims at showing a management solution to a local area network, from the perspective of accounting management. After a short review of the main topics in the computer network management field, the work focus attention in account management, describing its capabilities and tools. Also, it shows a study with the deployment of Nagios and Cacti tools, as well as an analysis of the associated results.

Microclima e bioindicadores paleoclimáticos em paisagens com ocorrência de areais em São Francisco de Assis, RS, Brasil

Silva, Dakir Larara Machado da
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
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A tese que fundamenta esta pesquisa centra-se na idéia de que as cactáceas encontradas na área de estudo são bioindicadoras de climas pretéritos. Suas características em escala micro são similares aos seus ambientes de origem ou, ao sofrerem transformações, apresentam condições para estabelecimento e proliferação nesses ambientes. Mais especificamente, o objetivo é de analisar em escala microclimática, diferentes compartimentos da paisagem em áreas de ocorrência de areais, no município de São Francisco de Assis, Rio Grande do Sul, Brasil. Isso possibilitará o reconhecimento das condições ambientais que dão suporte à variação e densidade de cactáceas e demais espécies (arbóreas e arbustivas) que compõem a cobertura vegetal em diferentes setores e, sua possível identificação como indicadores bioclimáticos. Derivada da necessidade de pesquisa em escala climática de detalhe elaborou-se, preliminarmente, uma análise em escala local. Posteriormente, através de um estudo experimental realizado através de medições de parâmetros climáticos ao longo de um ano experimental, analisamos o microclima da área objeto de investigação tomando como suporte unidades de paisagem. Identificamos, para cada unidade...

Use of cacti as heat sources by thermoregulating Mabuya agilis (Raddi) and Mabuya macrorhyncha Hoge (Lacertflia, Scincidae) in two restinga habitats in southeastern Brazil

Vrcibradic,Davor; Rocha,Carlos Frederico Duarte
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2002 Português
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Lizards may benefit from gain of heat from contact with the substrate via conduction. In this study, evidence that the lizards Mabuya agilis (Raddi, 1823) and Mabuya macrorhynclui Hoge, 1946 (Scincidae) inhabiting two restinga habitats in southeastern Brazil (Grussaf, Rio de Janeiro and Praia das Neves, Espfrito Santo), may shift microhabitat preferences along the day, and that such shifts may be related to the use of cacti surfaces as direct sources of heat is presented. For both species, body temperature (Tb) was always significantly correlated (p < 0,05) with air temperature (Ta). Tb was significantly correlated (p < 0,0.5) with substrate temperature (Ts) for M. agilis collected on cacti, but not for specimens collected on the ground. For M. macrorhyncha collected on cacti, both Ta and Ts were more important in conjunction than separately, in explaining lizard Tb. Use of cacti as perches by M. agilis was more frequent during late afternoon when environmental temperatures are declining, but such a trend was not evident for M. macrorhynclui. We suggest that the use of cacti as direct heat sources may be more evident in the ground-dwelling M. agilis than in the scansorial M. macrorhynclui.

CACTI: Free, Open-Source Software for the Sequential Coding of Behavioral Interactions

Glynn, Lisa H.; Hallgren, Kevin A.; Houck, Jon M.; Moyers, Theresa B.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 16/07/2012 Português
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The sequential analysis of client and clinician speech in psychotherapy sessions can help to identify and characterize potential mechanisms of treatment and behavior change. Previous studies required coding systems that were time-consuming, expensive, and error-prone. Existing software can be expensive and inflexible, and furthermore, no single package allows for pre-parsing, sequential coding, and assignment of global ratings. We developed a free, open-source, and adaptable program to meet these needs: The CASAA Application for Coding Treatment Interactions (CACTI). Without transcripts, CACTI facilitates the real-time sequential coding of behavioral interactions using WAV-format audio files. Most elements of the interface are user-modifiable through a simple XML file, and can be further adapted using Java through the terms of the GNU Public License. Coding with this software yields interrater reliabilities comparable to previous methods, but at greatly reduced time and expense. CACTI is a flexible research tool that can simplify psychotherapy process research, and has the potential to contribute to the improvement of treatment content and delivery.

Sonoran Desert columnar cacti and the evolution of generalized pollination systems

Hamrick, J.L.; Nason, John D.; Holland, J. Nathaniel; Sahley, Catherine T.; Fleming, Theodore H.
Fonte: Ecological Society of America Publicador: Ecological Society of America
Tipo: Artigo de Revista Científica
Português
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journal article; We studied variation in flowering phenology, fruit and seed set, and the abundance of the pollinators of four species of night-blooming Sonoran Desert columnar cacti for up to eight years at one site in Mexico and one year at one site in Arizona. We determined how spatiotemporal variation in plant–pollinator interactions affects the evolution of generalized pollination systems. We conducted pollinator exclusion and hand pollination experiments to document annual variability in pollinator reliability and to determine whether pollination systems were redundant (different species are partially or totally substitutable) or complementary (different species have an additive effect on fruit set). The cacti we studied included three species with generalized pollination systems involving bats, birds, and bees (cardon, Pachycereus pringlei; saguaro, Carnegiea gigantea; and organ pipe, Stenocereus thurberi) and one specialized moth-pollinated species (senita, Lophocereus schottii). We predicted that the migratory lesser long-nosed bat, Leptonycteris curasoae, is a less reliable pollinator than birds and bees, and that cacti with generalized pollination systems have more variable flowering phenologies than the specialized species. Annual time of peak flowering and mean size of flower crops were relatively invariant in saguaro and organ pipe. Time of peak flowering in cardon varied by as much as six weeks...

Tissue culture of ornamental cacti

Pérez-Molphe-Balch,Eugenio; Santos-Díaz,María del Socorro; Ramírez-Malagón,Rafael; Ochoa-Alejo,Neftalí
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2015 Português
Relevância na Pesquisa
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Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family.

Conservation network design for endemic cacti under taxonomic uncertainty

Carvallo, Gastón; Bustamante Araya, Ramiro Osciel; Guerrero, Pablo C.; Duarte, Milen
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo de revista
Português
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Artículo de publicación ISI; The utility of spatial conservation prioritization (SCP), could be limited by the biases produced by taxonomic uncertainty and by the lack of an accepted taxonomic checklist for a diverse group of species. Using information on the endemic cacti of the Atacama Desert and Mediterranean Chile, we assessed the implications for SCP of the existence of two contrasting taxonomies. Biological and socioeconomic criteria were combined to design conservation networks for two widely used taxonomic checklists of endemic Chilean cacti. We analyzed the spatial distribution of these conservation networks to assess the congruence of the taxonomic checklists and evaluated whether our models match the geographic distribution of the National System of Protected Areas. The conservation networks had low similarity. However, consensus scenarios revealed several coincident priority sites. Gap analyses indicated that one-third of the species were completely unprotected but that all species were satisfactorily protected in the consensus scenario. Consensus scenarios based on different checklists can improve SCP because this approach is less affected by taxonomic uncertainty. It is more conservative (without a priori taxonomic decisions) and robust (priority sites are supported by more than one scenario). Given the narrow distribution of cacti...

On a conjecture for the signless Laplacian spectral radius of cacti with given matching number

Shen, Yun; You, Lihua; Zhang, Minjie; Li, Shuchao
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/11/2015 Português
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A connected graph $G$ is a cactus if any two of its cycles have at most one common vertex. Let $\ell_n^m$ be the set of cacti on $n$ vertices with matching number $m.$ S.C. Li and M.J. Zhang determined the unique graph with the maximum signless Laplacian spectral radius among all cacti in $\ell_n^m$ with $n=2m$. In this paper, we characterize the case $n\geq 2m+1$. This confirms the conjecture of Li and Zhang(S.C. Li, M.J. Zhang, On the signless Laplacian index of cacti with a given number of pendant vetices, Linear Algebra Appl. 436, 2012, 4400--4411). Further, we characterize the unique graph with the maximum signless Laplacian spectral radius among all cacti on $n$ vertices.; Comment: 20

Independent sets in chain cacti

Sedlar, Jelena
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/05/2011 Português
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In this paper chain cacti are considered. First, for two specific classes of chain cacti (orto-chains and meta-chains of cycles with h vertices) the recurrence relation for independence polynomial is derived. That recurrence relation is then used in deriving explicit expressions for independence number and number of maximum independent sets for such chains. Also, the recurrence relation for total number of independent sets for such graphs is derived. Finaly, the proof is provided that orto-chains and meta-chains are the only extremal chain cacti with respect to total number of independent sets (orto-chains minimal and meta-chains maximal).; Comment: 18 pages, 5 figures

Enumeration of m-ary cacti

Bona, Miklos; Bousquet, Michel; Labelle, Gilbert; Leroux, Pierre
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The purpose of this paper is to enumerate various classes of cyclically colored m-gonal plane cacti, called m-ary cacti. This combinatorial problem is motivated by the topological classification of complex polynomials having at most m critical values, studied by Zvonkin and others. We obtain explicit formulae for both labelled and unlabelled m-ary cacti, according to i) the number of polygons, ii) the vertex-color distribution, iii) the vertex-degree distribution of each color. We also enumerate m-ary cacti according to the order of their automorphism group. Using a generalization of Otter's formula, we express the species of m-ary cacti in terms of rooted and of pointed cacti. A variant of the m-dimensional Lagrange inversion is then used to enumerate these structures. The method of Liskovets for the enumeration of unrooted planar maps can also be adapted to m-ary cacti.; Comment: LaTeX2e, 28 pages, 9 figures (eps), 3 tables

On several varieties of cacti and their relations

Kaufmann, Ralph M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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Motivated by string topology and the arc operad, we introduce the notion of quasi-operads and consider four (quasi)-operads which are different varieties of the operad of cacti. These are cacti without local zeros (or spines) and cacti proper as well as both varieties with fixed constant size one of the constituting loops. Using the recognition principle of Fiedorowicz, we prove that spineless cacti are equivalent as operads to the little discs operad. It turns out that in terms of spineless cacti Cohen's Gerstenhaber structure and Fiedorowicz' braided operad structure are given by the same explicit chains. We also prove that spineless cacti and cacti are homotopy equivalent to their normalized versions as quasi-operads by showing that both types of cacti are semi-direct products of the quasi-operad of their normalized versions with a re-scaling operad based on R>0. Furthermore, we introduce the notion of bi-crossed products of quasi-operads and show that the cacti proper are a bi-crossed product of the operad of cacti without spines and the operad based on the monoid given by the circle group S^1. We also prove that this particular bi-crossed operad product is homotopy equivalent to the semi-direct product of the spineless cacti with the group S^1. This implies that cacti are equivalent to the framed little discs operad. These results lead to new CW models for the little discs and the framed little discs operad.; Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-13.abs.html

A proof of a cyclic version of Deligne's conjecture via Cacti

Kaufmann, Ralph M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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In this note, we show that the normalized Hochschild co--chains of an associative algebra with a non--degenerate, symmetric, invariant inner product are an algebra over a chain model of the framed little discs operad which is given by cacti. In particular, in this sense they are a BV algebra up to homotopy and the Hochschild cohomology of such an algebra is a BV algebra whose induced bracket coincides with Gerstenhaber's bracket. To show this, we use a cellular chain model for the framed little disc operad in terms of normalized cacti. This model is given by tensoring our chain model for the little discs operad in terms of spineless cacti with natural chain models for $(S^1)^{\times n}$ adapted to cacti.; Comment: 20 pages, LaTex. New version with more expository text

Cacti and filtered distributive laws

Dotsenko, Vladimir; Griffin, James
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/09/2011 Português
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Motivated by the second author's construction of a classifying space for the group of pure symmetric automorphisms of a free product, we introduce and study a family of topological operads, the operads of based cacti, defined for every pointed topological space $(Y,\bullet)$. These operads also admit linear versions, which are defined for every augmented graded cocommutative coalgebra $C$. We show that the homology of the topological operad of based $Y$-cacti is the linear operad of based $H_*(Y)$-cacti. In addition, we show that for every coalgebra $C$ the operad of based $C$-cacti is Koszul. To prove the latter result, we use the criterion of Koszulness for operads due to the first author, utilising the notion of a filtered distributive law between two quadratic operads. We also present a new proof of that criterion which works over the ground field of arbitrary characteristic.; Comment: 30 pages

Tissue culture of ornamental cacti

Pérez-Molphe-Balch, Eugenio; Santos-Díaz, María del Socorro; Ramírez-Malagón, Rafael; Ochoa-Alejo, Neftalí
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2015 Português
Relevância na Pesquisa
27.717964%
Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family.

Ecological Attributes, Geographic Distribution and Endemism of Cacti from the São Francisco Watershed; Ecological Attributes, Geographic Distribution and Endemism of Cacti from the São Francisco Watershed

Meiado, Marcos V.; Machado, Marlon C.; Zappi, Daniela C.; Taylor, Nigel P.; Siqueira Filho, José A.
Fonte: Programa de Pós Graduação em Desenvolvimento e Meio Ambiente – PRODEMA Publicador: Programa de Pós Graduação em Desenvolvimento e Meio Ambiente – PRODEMA
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 02/05/2015 Português
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The purpose of this study is to assess the ecological attributes, geographic distribution, conservation status and endemism of cactus species in the São Francisco River Watershed (SFRW). In order to gather information on the cactus species found in the SFRW, three sources of information were used: collections from Brazilian herbaria, bibliographic references and online collections. The ecological attributes were related to (1) habitat specificity, (2) species habit, (3) pollination syndrome, and (4) groups of primary and secondary dispersers. Moreover, data from the three information sources cited above were used to assess geographic distribution of the cacti found in the SFRW. Species were divided into three categories according to the number of populations sampled: (1) widespread species: over 30 populations, (2) species with intermediate distribution: 11 to 30 populations, (3) locally distributed species: up to 10 populations. Conservation status of the cacti found in the SFRW was determined according to the classification of the International Union for Conservation of Nature and Natural Resources Red List. There were 108 cacti taxa scattered throughout the SFRW and 32.4% of the taxa are endemic. Species may be present in more than one ecosystem; most were found in areas of Caatinga (59.5%). The most common microhabitat was soil (62.5%). The globose habit (21.2%)...

The role of clonal and sexual spread in cacti species dominance at the Brazilian Caatinga; The role of clonal and sexual spread in cacti species dominance at the Brazilian Caatinga

Ribeiro, Elâine M.S.; Meiado, Marcos V.; Leal, Inara R.
Fonte: Programa de Pós Graduação em Desenvolvimento e Meio Ambiente – PRODEMA Publicador: Programa de Pós Graduação em Desenvolvimento e Meio Ambiente – PRODEMA
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 25/04/2015 Português
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A large part of flowering plants have sexual and asexual propagation. The occurrence of these reproductive modes is probably related to adaptive responses to environmental conditions, species distribution, genetic variation and the maintenance of multiple biological interactions. Here we examined populations of eight cacti species from Brazilian Caatinga (Arrojadoa rhodantha, Cereus jamacaru ssp. jamacaru, Harrisia adscendens, Pilosocereus gounellei ssp. gounellei, Pilosocereus pachycladus ssp. pernambucoensis, Melocactus zehntneri, Tacinga inamoena and Tacinga palmadora) and verified how clonal and sexual spread contribute to these species’ dominance. We surveyed populations of these species in 30 plots of 50x20m in natural areas of Caatinga at Parnamirim municipality, in these plots adults and seedlings/saplings via sexual and asexual reproduction were recorded. We registered a total 2692 individuals from the eight studied species. The most abundant species were A. rhodantha, P. gounellei ssp. gounellei, M. zehntneri, T. inamoena and T. palmadora (> 200 individuals registered), while C. jamacaru ssp. jamacaru, H. adscendens and P. pachycladus ssp. pernambucoensis (< 100 individuals registered). We verified that the high investment in sexual...

Descripción de los estados adultos e inmaduros y aspectos bioecológicos de Heterothrips cacti (Thysanoptera: Heterothripidae)

Zamar,María I.; Neder de Román,Lilia E.; Montero,Teresa E.; Torréns,Javier
Fonte: Revista de la Sociedad Entomológica Argentina Publicador: Revista de la Sociedad Entomológica Argentina
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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Se describen e ilustran los estados inmaduros de Heterothrips cacti Hood y se discuten las características biológicas y ecológicas de esta especie en las zonas semiáridas y de altura de Jujuy (Argentina). Los muestreos de frecuencia quincenal se realizaron en San Pedrito durante el período de floración de Opuntia sulphurea var. hildmannii en la temporada 2006-2007. La muestra consistió en cinco flores tomadas al azar de cada condición de evolución de las mismas. Para conocer las plantas hospedadoras y la distribución de H. cacti, se realizaron muestreos periódicos de la vegetación silvestre en la Prepuna y Puna de Jujuy. Los estudios biológicos se llevaron a cabo en el laboratorio, acondicionando flores de O. sulphurea con huevos de H. cacti en cajas de cría, para controlar la evolución del ciclo de vida. Heterothrips cacti es una especie antófila, oligófaga asociada a cactáceas, de amplia distribución en la Prepuna y Puna jujeñas. La biología de H. cacti está correlacionada con la de su planta hospedadora, O. sulphurea que presenta dos generaciones al año. Asimismo, el ciclo de vida está asociado con la evolución de la flor de la cactácea. El tiempo de desarrollo de los estados inmaduros de la primera y segunda generación fue de 45 ± 1.5 días y 287 ±3 días respectivamente. El estadio de desarrollo por el que la especie atraviesa el período entre floraciones es larva II quiescente...

Cacti community structure in a tropical Mexican dry forest under chronic disturbance

Arias-Medellín,Luís Antonio; Flores-Palacios,Alejandro; Martínez-Garza,Cristina
Fonte: Sociedad Botánica de México A.C. Publicador: Sociedad Botánica de México A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 Português
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When agricultural lands in formerly dry forest are abandoned, chronic disturbance by livestock grazing and wood extraction may set back successional processes precluding older dry forest structure from be reached. We compare cacti density, richness, diversity and evenness in twelve 50 × 50 m plots: six plots in secondary dry forest and six plots in older conserved dry forest at Sierra de Huautla, Central Mexico. Cacti were identified, the life-form of each species was recorded and size was measured to assign individuals into four life-stage classes. Nine cacti species were registered across both forest types. In this dry forest, richness, diversity and evenness of cacti community increased in sites under chronic disturbance, whereas density was not significantly affected. Size structure at community level in the conserved forest showed an increase of individuals with size, whereas in the secondary forest, size structure showed an uneven distribution of individuals, as in populations that regenerate by pulses. In the secondary forest, there was a lower proportion of adults and they were in average, smaller than those in the conserved forest. Chronic disturbance may eventually change cacti community structure, affecting animals that depend on large arboreal cacti for food...