• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 9
  • 9
  • 6
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analýza mitochondriálních genů živočichů pro DNA barcoding / Analysis of animal mitochondrial genes for DNA barcoding

Brabencová, Klára January 2014 (has links)
The aim of this work is a literature review on the topic of the mitochondrial genome and DNA barcoding, building a dataset of mitochondrial sequences from GenBank database and creatione of a software function for extraction of individual genes that are present in the mitochondrial genome. This function was developed in Matlab. DNA barcoding is a method that uses short DNA sequence of mitochondrial genome for identification of species. There is no comprehensive work examining the appropriateness of different mitochondrial genes. This aim investigates the potential of other mitochondrial genes and evaluate their effectiveness for DNA barcoding and calculation of intra-and interspecific variability.
2

Morfološka varijabilnost vrsta roda Anacamptis Rich. (Orchidoideae, Orchidaceae) na području Balkanskog poluostrva i Panonske nizije / Morphological variability of species of the genusAnacamptis Rich. (Orchidoideae, Orchidaceae) in the Balkan Peninsula and the Pannonian Plain

Radak Boris 04 November 2019 (has links)
<p>Pored rodova evropskih orhideja koji se odlikuju velikim stepenom diverzifikacije, kao i značajnim brojem novoopisanih vrsta, kao &scaron;to su <em>Ophrys </em>ili<em> Epipactis,</em> rod<em> Anacamptis </em>je ostao poprilično zapostavljen u orhidolo&scaron;kim istraživanjima. Na predstavnicima ovog roda uglavnom su vr&scaron;ena molekularna istraživanja, u kojima je bio uključen i veći broj drugih rodova.Takođe, urađene su i opsežne studije, ali samo na pojedinim vrstama. Morfolo&scaron;ka istraživanja su bila veoma retka i uz par uzuzetaka, ograničena na geografski mala područja i na jednu ili nekoliko morfolo&scaron;ki sličnih vrsta. Analiza morfolo&scaron;ke varijabilnosti ovolikog broja taksona roda<em> Anacamptis</em> na geografski relativno velikom području kakvo je Balkansko poluostrvo, kao i deo Panonske nizije koji se oslanja na njega, do&nbsp; sada nije bilo sprovedeno. Morfolo&scaron;kim analizama bili su podvrgnuti gotovo svi predstavnici ovog roda u rangu vrste i podvrste, a koji se javljaju na području kopnenog dela Balkanskog poluostrva, kao i južnog oboda Panonske nizije. Sprovedene su jednostrane i uporedne morfolo&scaron;ke analize sa detaljnomobradom podataka metodama bazične, univarijantne i multivarijantne statistike. Do sada najvećim istraživanjem taksona roda<em> Anacamptis</em>, po broju obrađenih jedinki i području na kom je sprovedeno, bila je obuhvaćena 2001 jedinka iz 185&nbsp; populacija. Analizirane su prirodne populacije, ali i materijal iz Herbarijuma BUNS. Ukupno je definisano 69 morfolo&scaron;kih karaktera, kvantitativnih i kvalitativnih, a među njima su traženi oni koji imaju potencijalno diferencijalni karakter između opisanih vrsta i infraspecijskih taksona. Analize su obuhvatile i interpopulacionu morfolo&scaron;ku varijabilnost u okviru svakog taksona, a u cilju uočavanja postojanja određenih geografskih obrazaca njenih promena. Morfolo&scaron;ki karakteri koji su se u sprovedenim analizama pokazali kao taksonomski informativni, iskori&scaron;ćeni su za formiranje dihotomog ključa za determinaciju taksona roda <em>Anacamptis</em> prisutnih na istraživanom području. Analizama je utvrđen veliki broj karaktera koji su statistički značajno različiti između analiziranih populacija, podvrsta i vrsta. Većina karaktera je pokazala umerenu ili nisku varijabilnost, a u retkim slučajevima i povećanu. Karakteri cveta međusobno su statistički značajno korelisani,većina slabo do umereno, dok su oni na listićima kacige, kao i između labeluma i drugih delova cveta jako do izrazito jako povezani. Jedini takson koji nije pokazao nikakvu infraspecijsku diferencijaciju, a koji se odlikuje velikom unutari interpopulacionom varijabilno&scaron;ću je<em> A. pyramidalis</em>. Iz istog razloga je pokazano kao neosnovano izdvajanje jedinki iz različitih delova njegovog areala u do sada opisane infraspecijske oblike. Potvrđena je niska morfolo&scaron;ka varijabilnost uskorasprostranjene vrste <em>A. boryi.</em> Kod svih preostalih istraživanih taksona utvrđeno je postojanje određenih obrazaca geografske interpopulacione varijabilnosti i infraspecijske struktuiranosti.Populacije <em>A. laxiflora</em> subsp. <em>laxiflora </em>mogu se podeliti na jadranske i kontinentalne, pri čemu najzapadnije pokazuju i najmanje vrednosti analiziranih karaktera. <em>A. coriophora </em>subsp.<em> fragrans </em>se pokazala kao manje varijabilnom od tipske podvrste, ali je u okviru nje kao zaseban takson izdvojen var. <em>hermae </em>kao fenolo&scaron;ki, ekolo&scaron;ki i morfolo&scaron;ki odvojen u odnosu na ostaleispitivane populacije. Tipska podvrsta pokazuje obrazac variranja ukupne morfolo&scaron;ke varijabilnosti u pravcu zapad-istok. Kao karakteri koji su najznačajniji za diferencijaciju podvrsta vrste<em> A. palustris</em> izdvojeni su dužina i &scaron;irina brakteje, stepen diferenciranosti labeluma na režnjeve, kao i dubina sinusa koja ih razdvaja. Populacije<em> A. palustris</em> subsp. <em>elegans</em> moguće je podeliti na tri geografski i morfolo&scaron;ki definisane grupe &ndash; istočnobalkansku, zapadnobalkansku i periferne populacije sa severa Srbije i iz Slovenije. Kao diferencijalni karakteri između taksona sekcije <em>Laxiflorae</em> pokazali su se odnos između dužine plodnika i brakteje, kao i dužina srednjeg režnja labeluma. Vrsta<em> A. morio </em>je po prvi put jasno morfolo&scaron;ki i arealno podeljena na dve podvrste na istraživanom području. Podvrste pokazuju velika preklapanja vrednosti morfolo&scaron;kih karaktera, ali se obe odlikuju specifičnim karakteristikama cveta, pre svega labeluma na osnovu kojih ih je moguće razlikovati. Definisani su areali podvrsta<em> A.morio </em>na istraživanom području &ndash; tipska podvrsta je prevashodno severnija i zapadnija, dok je subsp.<em> caucasica </em>južnija i istočnija. Prvu odlikuju krupniji cvetovi, bubrežastih labeluma sa srednjim režnjem koji ne prevazilazi značajno dužinu bočnih, dok je druga sa sitnijim cvetovima i snažno isturenim srednjim režnjem. Obe podvrste mogu se podeliti na grupe populacija sa jasno definisanim geografskim raspostranjenjem. Vrsta <em>A. papilionacea </em>je po prvi put morfolo&scaron;ki istaživana na većem broju primeraka, a ne prostim poređenjem pojedinačnih primeraka iz različitih delova areala. Pokazana je morfolo&scaron;ka diferenciranost na dve podvrste &ndash; tipsku i subsp. aegaea, koje se jasno morfolo&scaron;ki razlikuju i zauzimaju različite delove areala vrste. U okviru subsp. <em>papilionacea</em> registrovan je klinalni raspored morfolo&scaron;ke varijabilnosti u pravcu sever-jug. Registrovana su i tri hibrida, nova za područje pojedinih zemalja &ndash; A. <em>&times; gennarii</em> (Severna Makedonija),A. <em>&times; parvifolia</em> (Crna Gora) i A. &times; <em>timbali</em> (Srbija). Hibridi pokazuju generalnu morfolo&scaron;ku intermedijarnost u odnosu na roditelje, ali se odlikuju i novim stanjima karaktera, nezabeleženim kod roditeljskih taksona. Slični obrasci morfolo&scaron;ke varijabilnosti, kako na interpopulacionom nivou pojedinih vrsta, ali iizmeđu podvrsta svake istraživane vrste, pokazuju jasnu vezu između istraživanih taksona i jo&scaron; jednom opravdavaju njihovo zajedničko grupisanje u rod<em> Anacamptis.</em></p> / <p>Unlike the highly diversified and species-rich genera of European orchids, such as<em> Ophrys </em>or <em>Epipac</em>tis, the genus <em>Anacamptis </em>has remained quite neglected in orchidological research. Representatives of this genus, together with many others genera, were investigated mainly by molecular methods. Also, extensive studies have been done, but only on specific species. Morphological studies were very rare, and with a few exceptions, limited to geographically small areas and one or more morphologically similar species. Analysis of the morphological variability of so many taxa of the genus <em>Anacamptis</em>, in a is, in a geographically relatively large area such as the Balkan Peninsula, as geographically relatively large area such as the Balkan Peninsula, as well as the southern part of the Pannonian Plain, has not been conducted so far. Morphological analyses were<br />performed on almost all representatives of this genus,in the species and subspecies rank , occurring in the Balkan Peninsula mainland, as well as in the southern perimeter of the Pannonian Plain. Comparativemorphological analyses were conducted using the methods of basic, univariate and multivariate statistics.So far, the largest study of the genus&nbsp; nacamptis, by the number of processed individuals and the area in which it was conducted, included 2001 individuals from 185 populations. Natural populations and&nbsp; material from the BUNS Herbarium were analyzed. A total of 69 morphological characters, quantitative and&nbsp; qualitative, were defined, and those that have a potentially differential character among analyzed species and infraspecific taxa were selected. The analyzes also included interpopulation morphological variability within each taxon, to identify the existence of specific geographic patterns of its changes. The morphological characters that proved to be taxonomically informative, were used to form the dichotomous key for the determination of the genus Anacamptis members, presented in the study area. The analyzes identified a large number of characters that were statistically significantly different between the analyzed populations, subspecies, and species. Most of the characters showed moderate or low variability, and in rare cases increased variability. Flower&rsquo;s characters were statistically significantly correlated with each other, most of them weakly to moderately, while those of the sepals and petals, as well as between the&nbsp; labellum and other parts of the flower, were very strongly correlated. The only taxon that has not shown any infraspecific differentiation (except <em>A. boryi</em>), and which is characterized by high intra- and interpopulation variability, is A. pyramidalis. For the same reason, it has been shown as unjustified to separate individuals from different parts of species range into infraspecific forms. The low morphological variability of the narrowly distributed A. boryi was confirmed. In all other taxa studied, the existence of certain patterns of geographical interpopulation variability and infraspecific structuring was detected. <em>A. laxiflora</em> subsp. <em>laxiflora</em> populations can be divided into two groups &ndash; Adriatic and Continental, with the lowest characters values measured among the westernmost populations. <em>A. coriophora s</em>ubsp. <em>fragrans</em> proved to be less variable than the type subspecies, but within it, a new variety (var. hermae) as phenological, ecological and morphologically distinct from other studied populations was described. The typesubspecies has a transition of morphological variability in a west-east direction. The characters that are the most important for differentiation of A. palustris subspecies are the&nbsp; bract length and width, the degree of labellum differentiation into lobes, and the depth of the sinuses that separate them. Populations of A. palustris subsp. elegan<em>s </em>can be divided into three geographically and morphologically defined groups &ndash; Eastern Balkan, Western Balkan and peripheral populations from the North Serbia and Slovenia. Differential characters&nbsp; among the Laxiflorae section taxa are ration between the ovary length and bract length, as well as the labellum middle lobe length. For the first time, species <em>A. morio </em>is morphologically and geographically divided into two subspecies, in the&nbsp; study area. Analyzed subspecies have great overlapping values for many morphological characters, but both are characterized by specific flower&rsquo;s characteristics, above all labellum shape. On this basis, it is possible to distinguish them. Areals of <em>A</em>. <em>morio </em>subspecies were defined &ndash; the type subspecies is predominantly northern and western,while subsp. caucasica is southern and eastern. The first is characterized by larger flowers, renal shape labellum with a median lobe that does not exceed significantly the length of the lateral ones, while the second subspecies has smaller flowers and strongly projecting the median lobe. Both subspecies can be divided into groups of populations that have clearly defined geographical distribution. For the first time, A. papilionacea was morphologically investigated on a larger number of specimens, unlike previous&nbsp;&nbsp; researches in which individual specimens from different parts of the range were simply compared. Morphological differentiation into two subspecies was shown &ndash; type and subsp. aegaea. They are morphologically distinct and occupy different parts of the species range. Within the subsp. papilionacea a clinal distribution of morphological variability in the north-south direction was recorded. Three taxa of hybrid origin, new for the area of North Macedonia (A.<em> &times; gennari</em>i), Montenegro (A. <em>&times; parvifolia</em>) and Serbia (A. &times; t<em>imbali</em>) were registered. Hybrids exhibit a general morphological intermediacy between parents but are also distinguished by new character states that were not observed in<br />parental taxa. Similar patterns of morphological variability, both at the interpopulation level ofindividual species and between the subspecies of each species studied, show a clear relationship between the studied taxa and once again justify their grouping into the genus <em>Anacamptis.</em></p>
3

Kraniometrická studie středoevropských populací bělozubek Crocidura suaveolens a C. leucodon (Mammalia: Soricomorpha) / Craniometric study of Central European populations of the white-toothed shrews Crocidura suaveolens and C. leucodon (Mammalia: Soricomorpha)

Milerová, Petra January 2014 (has links)
Interspecific and intraspecific size variability of the skull, mandibles and teeth of the lesser white- toothed shrew Crocidura suaveolens and the bicolored white-toothed shrew C. leucodon was studied on material of 350 skulls and 465 mandibles of white-toothed shrews obtained by analysis of the barn owl pellets originating from four regions in the Czech Republic and one region in the southern Slovakia. C. suaveolens was present in all regions under study, while sympatric C. leucodon occurred in three regions only. In total, 21cranial and dental measurements and 4 mandibular measurements were investigated. It was found that the most reliable measurement enabling discrimination between skulls of both species in the whole studied material is the lenght of the lower dental row. If skulls of both species were evaluated separately for each area of their sympatry it was possible to use also the distance between second molars M2 and the width of premolar P4 . Skulls of these two species can also be distinguished by bivariate graphs using the length and width of premolar P4 and the palatal length. We studied relationships between cranial measurements of both species and geoclimatic factors such as longitude, latitude, mean annual temperature and mean annual percipitation. It was found that variability of...
4

Explorace, neofobie a potravní konzervatismus u sýkor / Exploration, neophobia and dietary conservatism in tits (Paridae)

Beranová, Eliška January 2012 (has links)
Neophobia and exploratory behaviour are two processes applied in great measure in birds' reactions towards novel stimuli. The specific demonstration of these two processes may differ between different species of birds as well as within them. We compared neophobia and exploratory behaviour in two species of tits (Paridae). Adult Great tits (Parus major) and Blue tits (Cyanistes caeruleus) did not differ neither in exploring novel environment and novel object nor in neophobia towards novel object near food. We have found great differences between juveniles of these two species. Juvenile Blue tits were more neophobic towards both novel objects. Age, sex and personality affected some differences within tested species. We tested whether there exist any differences in reactions towards novel food between and within species. We used red painted mealworm (larvae of Tenebrio molitor), house cricket (Acheta domestica) and aposematic bug (Pyrrhocoris apterus) as novel food. Adult wild-caught tits with plentiful experience with various feeds did not differ in reaction towards these types of novel food. In contrast hand-reared juvenile tits differed quite a lot. Juvenile Blue tits were more neophobic than juvenile Great tits towards all three types of novel food. We found dieraty conservatism, phenomenon...
5

Význam stanovištních podmínek pro interakce rostlin a bezobratlých herbivorů / The importance of enviromental conditions on plant-invertebrate herbivore interactions

Kuglerová, Marcela January 2017 (has links)
Plants and herbivores influence each other for more than million years. Most studies are focused on interspecific variability in herbivory intensity, but little i known about intraspecific variability and what controls it. Environmental conditions can determine intraspecific variation. Goal of this thesis is to examine importance of environmental conditions and interspecific variation for invertebrate herbivory preferences. Plant material that was used in experiments comes from several species from subfamily Carduoideae. Preferences of invertebrate herbivores are tested in food-choice experiments. Plastic arenas are made for these experiments, in which leaves are put in small tubes that are placed along the periphery. After herbivores are placed in to arena, arena is covered by net to ensure that herbivores can't escape. Plant material for experiments was grown in experimental garden and was also brought from field. Plants from garden differ in productivity of soil and water regime. In experiments with field material, plant leaves were collected from eight localities, four fields and four grasslands. Leaves were scanted before and after each experiment. Scans were processed and the amount of consumed leaf tissue was determined. For plant characteristics I measured plant functional traits, specific...
6

Diversité interspécifique de l'efficience d'utilisation de l'eau des acacias sahéliens et australiens / Inter-specific diversity of water use efficiency among sahelian and australian acacias

Konaté, Nianguiri Moussa 12 July 2010 (has links)
Le principal objectif de ce travail était de déterminer l’efficience d’utilisation de l’eau (WUE) de diverses espèces d’acacias d’origine Australienne et Sahélienne par la discrimination isotopique au niveau de la feuille (Δ13Cf) et par différentes techniques de mesure. Les acacias ont montré une forte variabilité interspécifique de Δ13Cf. Cette variabilité a été confirmée par les mesures directes d’échanges gazeux au niveau des feuilles (efficience intrinsèque d’utilisation de l’eau, Wi) et par des mesures effectuées au niveau de la plante entière (efficience de transpiration, TE). Une forte variabilité interspécifique des traits foliaires(densité stomatique DS, proportion d’azote dans les feuilles %N, surface massique SLA, assimilation nette du CO2 à la saturation Asat, conductance stomatique en vapeur d’eau à la saturation gssat) et de la croissance (ratio biomasse racinaire sur biomasse aérienne R/S) a également été constatée entre les espèces. WUE était pratiquement contrôlée par gssat.L’hypothèse selon laquelle les espèces se développant dans les zones arides présenteraient une WUE plus élevée n’a pas été vérifiée. Au contraire, les espèces des zones semi-humides ont présenté une WUE plus élevée que celles de zones semi-arides et arides. / The main objective of this work was to compare water use efficiency (WUE) among various Australian and Sahelian acacia species using isotope discrimination at leaf level (Δ13Cf) and various methods of measurement. Acacia species exhibited a large inter-specific variability of Δ13Cf. This variability was confirmed by direct leaf gas exchange measurements (intrinsic water use efficiency, Wi) and by measurement at the whole plant level (transpiration efficiency, TE). A large interspecific variability of leaf traits (stomatal density DS, leaf nitrogen concentration %N, specific leaf area SLA, net CO2 assimilation of the saturation Asat, stomatal conductance for water vapor of the saturation gssat) and growth characteristics (root shoot biomass ratio R/S) has also been reported. WUE was controlled for gssat. The hypothesis that the species from arid areas exhibit higher WUE was not confirmed. In contrast, the species from semi-wet area exhibited a higher WUE than those from semi-arid and arid zones
7

Padrões e processos de organização de comunidades de plantas lenhosas : nicho, evolução e biogeografia histórica

Carlucci, Marcos Bergmann January 2014 (has links)
Abordagens funcionais e filogenéticas têm sido amplamente utilizadas no estudo de ecologia de comunidades e têm propiciado um melhor entendimento de como atributos funcionais e sua evolução influenciam padrões ecológicos observados atualmente na natureza. A incorporação da variabilidade intraespecífica em estudos recentes de ecologia de comunidades vegetais tem demonstrado que, apesar de a variabilidade intraespecífica de um atributo ser normalmente menor do que sua variabilidade interespecífica, estudos que consideram a variabilidade intraespecífica inferem mecanismos de organização de comunidades com mais acurácia. Além disso, abordagens analíticas que incluem a variabilidade intraespecífica em estudos de comunidades possibilitam integrar as escalas de populações e comunidades em ecologia. Abordagens filogenéticas recentes permitem a avaliação da interação entre composição filogenética de bancos regionais de espécies e a estrutura filogenética local de comunidades, o que permite a inferência de processos históricos e ecológicos que estruturam comunidades atuais. O objetivo geral desta tese foi avaliar padrões e inferir processos de organização de comunidades de plantas lenhosas da escala local à regional. Para isso, utilizei abordagens baseadas em atributos funcionais para avaliar o nicho de indivíduos (capítulo 2) e das espécies (capítulo 2 e 3) e abordagens filogenéticas para avaliar como a evolução influencia a similaridade funcional entre as espécies (capítulo 3), a formação de bancos de espécies locais (capítulo 3) e regionais (capítulo 4) e a estruturação de comunidades locais (capítulo 4). No capítulo 2, avaliei qual a importância relativa da substituição (turnover) de espécies e da variabilidade intraespecífica nas respostas médias e de dispersão de área foliar específica no nível de comunidade a um gradiente de abertura de dossel em uma metacomunidade de árvores juvenis. Nesse capítulo, concluí que a variabilidade intraespecífica é fundamental para a organização de comunidades lenhosas em florestas e arbustais, pois a área foliar específica dentro da mesma espécie varia conforme o ambiente e o contexto local de espécies interatoras. Essa plasticidade permite o estabelecimento de espécies em uma porção maior do gradiente de abertura do dossel. No capítulo 3, avaliei se espécies ocorrentes tanto na floresta quanto no campo diferem de espécies restritas à floresta ou ao campo quanto a resposta de seus atributos a espécies coocorrentes e ao gradiente ambiental. Concluí que uma ação combinada entre área foliar específica, espessura foliar e densidade de folhagem ajuda a explicar a organização de comunidades de plantas lenhosas em ecótonos floresta-campo. A plasticidade nesses atributos permite a colonização do campo por espécies que também ocorrem na floresta. No capítulo 4, avaliei se há associação entre a estrutura filogenética local (agrupamento ou repulsão) de comunidades de árvores e a distribuição geográfica de grandes linhagens de angiospermas no Neotrópico e Afrotrópico. A conclusão foi que diferenças regionais de composição filogenética entre o Neotrópico e o Afrotrópico são provavelmente um resultado de taxas diferenciais de especiação e extinção que seguiram a separação de Gondwana e atualmente influenciam a estrutura filogenética local de comunidades de árvores de florestas pluviais nos dois reinos. / Functional and phylogenetic approaches have been widely used in community ecology studies and have provided a better understanding of how functional traits and their evolution influence ecological patterns that are currently observed in nature. The incorporation of intraspecific variability in recent plant community ecology studies have demonstrated that, despite intraspecific variability of a given trait extent be usually lower than its interspecific variability, studies that account for intraspecific variability more accurately infer mechanisms of community assembly. Moreover, analytical approaches that incorporate intraspecific variability in community ecology studies enable integrating population and community scales in ecology. Recent phylogenetic approaches permit evaluating the interaction between the phylogenetic composition of regional species pools and local phylogenetic structure of communities, which enables the inference of historical and ecological processes structuring current communities. The general aim of this dissertation was to evaluate and infer assembly processes of woody plant communities from local to regional scales. For this, I used trait-based approaches to assess the niche of individuals (chapter 2) and species (chapter 2 and 3) and community phylogenetics approaches to evaluate how evolution influences the trait similarity between species (chapter 3), the formation of local and regional species pools (chapter 3 and 4, respectively) and the structuring of local communities (chapter 4). In chapter 2, I evaluated what is the relative importance of species turnover and intraspecific variability to the variation in trait mean and spread responses of specific leaf area at the community level across a canopy openness gradient in a tree juvenile metacommunity. In this chapter, I conclude that intraspecific variability is essential to woody community assembly in forests and shrublands, since specific leaf area within the same species varies according to the environment and local context of interacting species. This plasticity permits species establishment in a wider portion of the canopy openness gradient. In chapter 3, I evaluated whether species both in forest and grassland differ from species restricted to either forest or grassland regarding their trait-based responses to co-occurring species and environmental gradient. I concluded that an interplay between specific leaf area, leaf thickness and foliage density help explaining the assembly of woody plant communities in forest-grassland ecotones. The plasticity in these traits enables the colonization of the grassland by species that also occur in the forest. In chapter 4, I evaluated whether there is association between local phylogenetic structure (clustering or overdispersion) of tree communities and geographical distribution of major angiosperm lineages in the Neotropics and Afrotropics. In this chapter, I concluded that regional differences in phylogenetic composition between the Neotropics and Afrotropics are likely an outcome of differential rates of speciation and extinction following the breakup of Gondwana and currently influence local phylogenetic structure of rainforest tree communities in both realms.
8

Padrões e processos de organização de comunidades de plantas lenhosas : nicho, evolução e biogeografia histórica

Carlucci, Marcos Bergmann January 2014 (has links)
Abordagens funcionais e filogenéticas têm sido amplamente utilizadas no estudo de ecologia de comunidades e têm propiciado um melhor entendimento de como atributos funcionais e sua evolução influenciam padrões ecológicos observados atualmente na natureza. A incorporação da variabilidade intraespecífica em estudos recentes de ecologia de comunidades vegetais tem demonstrado que, apesar de a variabilidade intraespecífica de um atributo ser normalmente menor do que sua variabilidade interespecífica, estudos que consideram a variabilidade intraespecífica inferem mecanismos de organização de comunidades com mais acurácia. Além disso, abordagens analíticas que incluem a variabilidade intraespecífica em estudos de comunidades possibilitam integrar as escalas de populações e comunidades em ecologia. Abordagens filogenéticas recentes permitem a avaliação da interação entre composição filogenética de bancos regionais de espécies e a estrutura filogenética local de comunidades, o que permite a inferência de processos históricos e ecológicos que estruturam comunidades atuais. O objetivo geral desta tese foi avaliar padrões e inferir processos de organização de comunidades de plantas lenhosas da escala local à regional. Para isso, utilizei abordagens baseadas em atributos funcionais para avaliar o nicho de indivíduos (capítulo 2) e das espécies (capítulo 2 e 3) e abordagens filogenéticas para avaliar como a evolução influencia a similaridade funcional entre as espécies (capítulo 3), a formação de bancos de espécies locais (capítulo 3) e regionais (capítulo 4) e a estruturação de comunidades locais (capítulo 4). No capítulo 2, avaliei qual a importância relativa da substituição (turnover) de espécies e da variabilidade intraespecífica nas respostas médias e de dispersão de área foliar específica no nível de comunidade a um gradiente de abertura de dossel em uma metacomunidade de árvores juvenis. Nesse capítulo, concluí que a variabilidade intraespecífica é fundamental para a organização de comunidades lenhosas em florestas e arbustais, pois a área foliar específica dentro da mesma espécie varia conforme o ambiente e o contexto local de espécies interatoras. Essa plasticidade permite o estabelecimento de espécies em uma porção maior do gradiente de abertura do dossel. No capítulo 3, avaliei se espécies ocorrentes tanto na floresta quanto no campo diferem de espécies restritas à floresta ou ao campo quanto a resposta de seus atributos a espécies coocorrentes e ao gradiente ambiental. Concluí que uma ação combinada entre área foliar específica, espessura foliar e densidade de folhagem ajuda a explicar a organização de comunidades de plantas lenhosas em ecótonos floresta-campo. A plasticidade nesses atributos permite a colonização do campo por espécies que também ocorrem na floresta. No capítulo 4, avaliei se há associação entre a estrutura filogenética local (agrupamento ou repulsão) de comunidades de árvores e a distribuição geográfica de grandes linhagens de angiospermas no Neotrópico e Afrotrópico. A conclusão foi que diferenças regionais de composição filogenética entre o Neotrópico e o Afrotrópico são provavelmente um resultado de taxas diferenciais de especiação e extinção que seguiram a separação de Gondwana e atualmente influenciam a estrutura filogenética local de comunidades de árvores de florestas pluviais nos dois reinos. / Functional and phylogenetic approaches have been widely used in community ecology studies and have provided a better understanding of how functional traits and their evolution influence ecological patterns that are currently observed in nature. The incorporation of intraspecific variability in recent plant community ecology studies have demonstrated that, despite intraspecific variability of a given trait extent be usually lower than its interspecific variability, studies that account for intraspecific variability more accurately infer mechanisms of community assembly. Moreover, analytical approaches that incorporate intraspecific variability in community ecology studies enable integrating population and community scales in ecology. Recent phylogenetic approaches permit evaluating the interaction between the phylogenetic composition of regional species pools and local phylogenetic structure of communities, which enables the inference of historical and ecological processes structuring current communities. The general aim of this dissertation was to evaluate and infer assembly processes of woody plant communities from local to regional scales. For this, I used trait-based approaches to assess the niche of individuals (chapter 2) and species (chapter 2 and 3) and community phylogenetics approaches to evaluate how evolution influences the trait similarity between species (chapter 3), the formation of local and regional species pools (chapter 3 and 4, respectively) and the structuring of local communities (chapter 4). In chapter 2, I evaluated what is the relative importance of species turnover and intraspecific variability to the variation in trait mean and spread responses of specific leaf area at the community level across a canopy openness gradient in a tree juvenile metacommunity. In this chapter, I conclude that intraspecific variability is essential to woody community assembly in forests and shrublands, since specific leaf area within the same species varies according to the environment and local context of interacting species. This plasticity permits species establishment in a wider portion of the canopy openness gradient. In chapter 3, I evaluated whether species both in forest and grassland differ from species restricted to either forest or grassland regarding their trait-based responses to co-occurring species and environmental gradient. I concluded that an interplay between specific leaf area, leaf thickness and foliage density help explaining the assembly of woody plant communities in forest-grassland ecotones. The plasticity in these traits enables the colonization of the grassland by species that also occur in the forest. In chapter 4, I evaluated whether there is association between local phylogenetic structure (clustering or overdispersion) of tree communities and geographical distribution of major angiosperm lineages in the Neotropics and Afrotropics. In this chapter, I concluded that regional differences in phylogenetic composition between the Neotropics and Afrotropics are likely an outcome of differential rates of speciation and extinction following the breakup of Gondwana and currently influence local phylogenetic structure of rainforest tree communities in both realms.
9

Padrões e processos de organização de comunidades de plantas lenhosas : nicho, evolução e biogeografia histórica

Carlucci, Marcos Bergmann January 2014 (has links)
Abordagens funcionais e filogenéticas têm sido amplamente utilizadas no estudo de ecologia de comunidades e têm propiciado um melhor entendimento de como atributos funcionais e sua evolução influenciam padrões ecológicos observados atualmente na natureza. A incorporação da variabilidade intraespecífica em estudos recentes de ecologia de comunidades vegetais tem demonstrado que, apesar de a variabilidade intraespecífica de um atributo ser normalmente menor do que sua variabilidade interespecífica, estudos que consideram a variabilidade intraespecífica inferem mecanismos de organização de comunidades com mais acurácia. Além disso, abordagens analíticas que incluem a variabilidade intraespecífica em estudos de comunidades possibilitam integrar as escalas de populações e comunidades em ecologia. Abordagens filogenéticas recentes permitem a avaliação da interação entre composição filogenética de bancos regionais de espécies e a estrutura filogenética local de comunidades, o que permite a inferência de processos históricos e ecológicos que estruturam comunidades atuais. O objetivo geral desta tese foi avaliar padrões e inferir processos de organização de comunidades de plantas lenhosas da escala local à regional. Para isso, utilizei abordagens baseadas em atributos funcionais para avaliar o nicho de indivíduos (capítulo 2) e das espécies (capítulo 2 e 3) e abordagens filogenéticas para avaliar como a evolução influencia a similaridade funcional entre as espécies (capítulo 3), a formação de bancos de espécies locais (capítulo 3) e regionais (capítulo 4) e a estruturação de comunidades locais (capítulo 4). No capítulo 2, avaliei qual a importância relativa da substituição (turnover) de espécies e da variabilidade intraespecífica nas respostas médias e de dispersão de área foliar específica no nível de comunidade a um gradiente de abertura de dossel em uma metacomunidade de árvores juvenis. Nesse capítulo, concluí que a variabilidade intraespecífica é fundamental para a organização de comunidades lenhosas em florestas e arbustais, pois a área foliar específica dentro da mesma espécie varia conforme o ambiente e o contexto local de espécies interatoras. Essa plasticidade permite o estabelecimento de espécies em uma porção maior do gradiente de abertura do dossel. No capítulo 3, avaliei se espécies ocorrentes tanto na floresta quanto no campo diferem de espécies restritas à floresta ou ao campo quanto a resposta de seus atributos a espécies coocorrentes e ao gradiente ambiental. Concluí que uma ação combinada entre área foliar específica, espessura foliar e densidade de folhagem ajuda a explicar a organização de comunidades de plantas lenhosas em ecótonos floresta-campo. A plasticidade nesses atributos permite a colonização do campo por espécies que também ocorrem na floresta. No capítulo 4, avaliei se há associação entre a estrutura filogenética local (agrupamento ou repulsão) de comunidades de árvores e a distribuição geográfica de grandes linhagens de angiospermas no Neotrópico e Afrotrópico. A conclusão foi que diferenças regionais de composição filogenética entre o Neotrópico e o Afrotrópico são provavelmente um resultado de taxas diferenciais de especiação e extinção que seguiram a separação de Gondwana e atualmente influenciam a estrutura filogenética local de comunidades de árvores de florestas pluviais nos dois reinos. / Functional and phylogenetic approaches have been widely used in community ecology studies and have provided a better understanding of how functional traits and their evolution influence ecological patterns that are currently observed in nature. The incorporation of intraspecific variability in recent plant community ecology studies have demonstrated that, despite intraspecific variability of a given trait extent be usually lower than its interspecific variability, studies that account for intraspecific variability more accurately infer mechanisms of community assembly. Moreover, analytical approaches that incorporate intraspecific variability in community ecology studies enable integrating population and community scales in ecology. Recent phylogenetic approaches permit evaluating the interaction between the phylogenetic composition of regional species pools and local phylogenetic structure of communities, which enables the inference of historical and ecological processes structuring current communities. The general aim of this dissertation was to evaluate and infer assembly processes of woody plant communities from local to regional scales. For this, I used trait-based approaches to assess the niche of individuals (chapter 2) and species (chapter 2 and 3) and community phylogenetics approaches to evaluate how evolution influences the trait similarity between species (chapter 3), the formation of local and regional species pools (chapter 3 and 4, respectively) and the structuring of local communities (chapter 4). In chapter 2, I evaluated what is the relative importance of species turnover and intraspecific variability to the variation in trait mean and spread responses of specific leaf area at the community level across a canopy openness gradient in a tree juvenile metacommunity. In this chapter, I conclude that intraspecific variability is essential to woody community assembly in forests and shrublands, since specific leaf area within the same species varies according to the environment and local context of interacting species. This plasticity permits species establishment in a wider portion of the canopy openness gradient. In chapter 3, I evaluated whether species both in forest and grassland differ from species restricted to either forest or grassland regarding their trait-based responses to co-occurring species and environmental gradient. I concluded that an interplay between specific leaf area, leaf thickness and foliage density help explaining the assembly of woody plant communities in forest-grassland ecotones. The plasticity in these traits enables the colonization of the grassland by species that also occur in the forest. In chapter 4, I evaluated whether there is association between local phylogenetic structure (clustering or overdispersion) of tree communities and geographical distribution of major angiosperm lineages in the Neotropics and Afrotropics. In this chapter, I concluded that regional differences in phylogenetic composition between the Neotropics and Afrotropics are likely an outcome of differential rates of speciation and extinction following the breakup of Gondwana and currently influence local phylogenetic structure of rainforest tree communities in both realms.

Page generated in 0.1016 seconds