Members of the genus Hakea (Proteaceae) are sclerophyllous, evergreen perennial shrubs or small trees endemic to Australia, with 65% of species confined to the South-West Botanical Province (southwestern Australia). Southwestern Australian Hakea species possess two contrasting leaf morphologies (broad or terete leaves) and fire-related life forms (non-sprouting (fire-killed) or resprouting (fire-surviving)), with each species representing one of four leaf morphology-life form groups.Representative species within each group were studied to determine whether they display similar distribution and ecophysiological patterns at both the adult and seedling stages. The distribution of species within these groups was best based on averages and variations in annual temperature and rainfall. The highest percentage of terete leaved non-sprouters (25 species) occurred in areas of low-moderate rainfall with large annual temperature ranges, whereas terete leaved resprouters (14 species) displayed a patchy distribution. Broad leaved resprouters (28 species) dominated areas of strongly seasonal rainfall, with few species occurring in the drier regions. Broad leaved non-sprouters (33 species) were best represented in areas of low annual temperature. The distribution of non-sprouters/resprouters may be due to the effect of climatic factors on seedling recruitment and/or fire frequencies. Leaf morphology appears to have a more direct influence on species distribution, as broad leaves are favoured in regions of medium-high, seasonal rainfall (less stressful habitats) while terete leaves are better adapted to tolerate hot, dry environments.Terete leaves are either simple (needle-like) or 2-3 pronged, and, apart from their narrow width, are characterised by their greater leaf thickness (> 1 mm), smaller projected area and mass, higher leaf mass per area (a measure of sclerophylly) and a ++ / lower density than broad leaves. Broad leaves are much more variable in their shape. Increased leaf thickness and sclerophylly in terete leaves can be partially attributed to the presence of a central parenchyma core and increased palisade thickness. This core is surrounded a compact network of fibre-capped vascular bundles. Thickness and sclerophylly were good indicators of relative nutrient content in terete, but not broad leaves. Both leaf types have a thick cuticle (> 20 mu m) and sunken stomates, with terete leaves possessing a greater stomatal density than broad leaves. Broad leaves are bilateral and hence amphistomatous. Adult and seedling leaves (of a similar leaf type) differed in morphology, but not anatomy, with some species producing broad seedling leaves and terete adult leaves.Seedlings growing under optimal growth conditions (full sunlight, well watered) in pots showed no relationship between rate of growth and ecophysiology with respect to the four species groupings, although seedlings of non-sprouters and broad leaved species had higher transpiration and photosynthetic rates than seedlings of resprouters and terete leaved species respectively. In response to high air temperatures (> 35°C), leaf temperatures close to or lower than the surrounding air temperature only occurred for terete leaved species possessing small individual and total leaf areas. By maintaining leaf photosynthesis rates during periods of relatively high air temperatures, terete leaved seedlings were able to produce more biomass per leaf area while retaining a low leaf area per seedling mass. When subjected to periods of water stress (withholding water), differences in water relations were most evident between seedlings of non-sprouters and resprouters, with resprouter seedlings showing an ability to minimise the decrease in relative water content for a given decrease in XPP. ++ / Although terete leaves possess many xeromorphic attributes, terete leaved seedlings were not necessarily superior at avoiding/tolerating drought. Terete leaves in seedlings may have alternative heat dissipation and/or anti-herbivore properties.Seasonal water relations of adult plants were monitored for over a year, including a period of prolonged summer drought at four sites (two on laterite (rocky substrate) and two on deep sand). The eight species inhabiting the lateritic sites were more stressed (more negative xylem pressure potentials (XPP)) in summer than the eight species on sandy soils, with lower conductances and higher leaf specific resistivity (XPP/area-based transpiration, LSR). Broad leaved species had higher transpiration rates and LSR, and more negative midday XPP throughout the study than terete leaved species. When spring (predrought) and summer (drought) data were compared, non-sprouters had lower XPP in summer, and lower transpiration rates and conductances in both seasons than resprouters. Non-sprouters on lateritic sites had the lowest water relations values in summer (drought tolerators). There was a tendency for broad leaved resprouters on sandy soils to have higher summer water relations values (drought avoiders). Broad leaved non-sprouters on lateritic soils could be considered the most water stressed group, with substantial plant death during the summer period. Terete leaved species on sandy soils were the most conservative in their water usage.

Quercus praedelavayi Xing Y.W. et Zhou Z.K. sp. nov. is reported from the upper Miocene of the Xianfeng flora in central Yunnan, southwestern China. The fossil species is identified based on the detailed leaf morphological and cuticular examinations. The primary venation is pinnate and the major secondary venation is craspedodromous with regular spacing. Stomata are anomocytic and occur on abaxial epidermis. Trichome bases are unicellular and multicellular. The new fossil species shows the closest affinity with Quercus delavayi, an extant species distributing in southwestern China. The responses of the functional leaf traits to the climate change were studied by comparing the leaf characters of fossil species and its nearest living relative. The stomatal density of Q. praedelavayi is higher than Q. delavayi, which suggests a lower palaeoatmospheric CO2 concentration during the late Miocene. The trichome base density of Q. praedelavayi is higher than the extant Q. delavayi. Considering the palaeoclimatic reconstruction of Xianfeng flora, it rejected the hypothesis that increase in trichome density is an adaptation to the drier environment.

Quercus praedelavayi Xing Y.W. et Zhou Z.K. sp. nov. is reported from the upper Miocene of the Xianfeng flora in central Yunnan, southwestern China. The fossil species is identified based on the detailed leaf morphological and cuticular examinations. The primary venation is pinnate and the major secondary venation is craspedodromous with regular spacing. Stomata are anomocytic and occur on abaxial epidermis. Trichome bases are unicellular and multicellular. The new fossil species shows the closest affinity with Quercus delavayi, an extant species distributing in southwestern China. The responses of the functional leaf traits to the climate change were studied by comparing the leaf characters of fossil species and its nearest living relative. The stomatal density of Q. praedelavayi is higher than Q. delavayi, which suggests a lower palaeoatmospheric CO2 concentration during the late Miocene. The trichome base density of Q. praedelavayi is higher than the extant Q. delavayi. Considering the palaeoclimatic reconstruction of Xianfeng flora, it rejected the hypothesis that increase in trichome density is an adaptation to the drier environment.

Made available in DSpace on 2015-04-22T22:12:38Z (GMT). No. of bitstreams: 1 Marcos Melo Correa.pdf: 3085652 bytes, checksum: ad02fd98038c54ac33211ab40d13e32c (MD5) Previous issue date: 2013-03-23 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The internal taxonomical organization of the Chrysobalanaceae is problematical and studies are needed with large numbers of taxa. This work is an anatomical and morphological description of 20 species of Chrysobalanaceae from the genera Couepia, Licania and Parinari occurring in the Adolpho Ducke Forest Reserve, Manaus AM. Morphological observations were made using a stereomicroscope. In addition, leaves were cleared with sodium hydroxide to see details of venation pattern. We characterized the epidermis frontal view using the method of dissociation with Franklin solution and paradermal cuts. The petiole, midrib and mesophyll were analyzed by cross sections from the middle third. The species analyzed herein have the basic morphological pattern described for the family, with simple, alternate, distichous, petiolate leaves with stipules usually present in younger branches. Macroscopic characters such as the shape of the blade, stipule type and the presence or position of glands vary between species. The most recurrent venation pattern among the species studied is the eucamptodromous with the occurrence in some cases of mixed eucamptodromous / broquidodromous venation. The petiole vascularization in all species is formed by continuous or discontinuous rings, or two or three arcs. The vascular bundles of the midrib are organized into arcs formed by two or three collateral bundles or forming a closed ring which may present an inner phloematic arc. The predominant type of anticlinal contour in the upper surface of the leaves is straight, with varying forms in the lower surface. The species have paracytic stomata, some occurring in stomatal crypts. The mesophyll of all species is dorsiventral, with both sides lined by a thick cuticle in several species. The epidermal cells on the adaxial surface are tabular, cubic or rectangular in shape. Palisade tissue occurs in one to three layers of elongated cells and spongy parenchyma compression varies according to the species. Sheath extensions and columnar sclereids occur in various species. An identification key was developed, as well as standardized descriptions using morphological and anatomical features. The following anatomical characters contributed more to the diagnosis, showing greater variation per feature, and were of most use in the key: position of glands, position of stomata in the epidermal line, shape of the stipules, number of layers of the upper epidermis, number of accessory vascular bundles in the petiole and development of areoles. The character set is effective in differentiating between species. / Chrysobalanaceae apresenta organização taxonômica interna problemática e estudos são necessários contendo grande número de táxons. Este trabalho apresenta a descrição morfológica e anatômica de 20 espécies de Chrysobalanaceae dos gêneros Couepia, Licania e Parinari ocorrentes na Reserva Florestal Adolpho Ducke, Manaus AM. A caracterização morfológica foi realizada com observação em estereomicroscópio, além de diafanização com hidróxido de sódio para detalhamento do padrão de venação. A epiderme foi caracterizada em vista frontal com uso do método de dissociação com solução de Franklin e cortes paradérmicos. O pecíolo, a nervura central e o mesofilo foram analisados a partir de cortes transversais no terço médio. As espécies possuem o padrão morfológico básico descrito para a família, com folhas simples, alternas, dísticas, pecioladas, com estípulas presentes geralmente nos ramos mais jovens. Caracteres macroscópicos como o formato do limbo, tipo de estípulas e a presença ou posição das glândulas variam entre espécies. O padrão de venação mais recorrente entre as espécies é o eucamptódromo, com a ocorrência em alguns casos de venação mista eucamptódroma/broquidódroma. A vascularização do pecíolo em todas as espécies é formada por anéis contínuos ou descontínuos, ou ainda arcos variando de dois a três. O feixe vascular da nervura central organiza-se em arcos formados por feixes colaterais que estão dispostos em número de dois ou três, ou formando um anel fechado no qual pode estar presente um arco floemático. O tipo de contorno anticlinal predominante na face adaxial das folhas é reto, com formas variáveis na face abaxial. Os estômatos são paracíticos, alguns ocorrendo em criptas estomáticas. O mesofilo de todas as espécies é dorsiventral, com ambas as faces revestidas por cutícula espessa. As células epidérmicas da face adaxial apresentam formato tabular, cúbico ou retangular. Ocorrem no parênquima paliçádico de uma a três camadas de células alongadas e o parênquima lacunoso apresenta compactação variável de acordo com a espécie. Extensões de bainha e esclereides colunares são de ocorrência comum. As espécies apresentam características escleromórficas, como a cutícula espessa, extensões de bainhas de feixes vasculares e criptas estomáticas. Esses caracteres indicam adaptação ao ambiente florestal de solo pobre, bem como aos fatores que interferem na utilização adequada dos recursos hídricos. Estômatos acima da linha epidérmica foram a única característica que ocorreu exclusivamente em espécies de Licania. Foi elaborada uma chave de identificação, assim como descrições padronizadas utilizando os caracteres morfoanatômicos. Os caracteres anatômicos deram maior contribuição para a diagnose, pois apresentaram maior variação entre as espécies, sendo os principais utilizados na chave: posição das glândulas, posição dos estômatos na linha epidérmica, forma das estípulas, número de camadas da epiderme adaxial, número de feixes acessórios no pecíolo e desenvolvimento das aréolas. O conjunto de caracteres é eficaz na diferenciação entre espécies.

Leaf morphology of Quercus (oak) species is highly variable and complicated confounded with phenotypic plasticity and fluctuating asymmetry (FA). However, the study of variation is mostly limited to leaf morphology. This study was extended to plasticity and FA variations in Q. alba (white oak), Q. palustris (pin oak), and Q. velutina (black oak). It was hypothesized that light exposure, individual trees, leaf position, and other leaf traits will influence variation in these species. Leaves were sampled from trees of these species and their morphological traits were measured. Absolute asymmetry of leaf width and area were determined and plasticity of each species was calculated. The data were analyzed using nested ANOVA with General Linear Model. Leaf morphology, plasticity and FA varied across the species and light exposure was the main source of variation. Individual trees and several leaf covariate traits also influenced leaf morphological and FA variations in all species.

No description available.

Red alder (Alnus rubra) is a tree species with high economic and ecological importance. It is subject to defoliation during unpredictable, episodic outbreaks of tent caterpillars (Malacosoma spp.) that result in reduced growth, decreased wood production, unsightly appearance and mortality in severe cases. Alder trees are weakened by severe and repeated tent caterpillar defoliation, and this can increase the susceptibility of the trees to other pests, diseases and drought. Repeated attack by tent caterpillars can cause decline in red alder populations, which can have potential negative impacts on the ecological and economic benefits of the species. Evidence from other species has shown that plants produce phytochemicals for defense against herbivores at a cost to growth and reproduction, but the relative magnitude of the cost of allocating available resources to defense depends on the level of the resources, and the plant genotype. The quality of a plant as food for herbivores is influenced by leaf physical and biochemical traits, and these traits change during a growing season or upon attack by herbivores. My research aimed to explore the defense mechanisms of red alder against western tent caterpillars (Malacosoma californicum) and determine the resistance variation among and within red alder populations, and to evaluate red alder available resource (nitrogen) allocation to defense and growth. Bioassay feeding trials were conducted in 2014 and 2015 with western tent caterpillars (WTC) (M. californicum) on twenty red alder clones from ten provenances. Phenology and quality of red alder leaves as food for the defoliators were analyzed to determine if budburst, leaf chemical content, water content or physical traits are major determinants of western tent caterpillars preference for red alder leaves. In another experiment, one-year-old seedlings from 100 half-sib red alder families were treated with two levels of ammonium nitrate (NH4NO3) in two growing seasons in a common garden. Growth, herbivore defense-related traits and root nodulation were measured and ranked among the plant genotypes and between the two nitrogen (N) treatments. Leaves from the two N treatments and different alder families were also used for bioassay feeding trials with WTC larvae to determine effects of N and genotype on red alder herbivory resistance. In my final experiments, I harvested and analyzed leaves from three-year-old red alder trees from five different families on eight dates from early April to mid-October 2016 to quantify oregonin and total phenolics concentrations, and wound induction experiments were conducted to determine if the concentrations of the chemicals vary during a growing season and upon attack by insects. Alder clones and families differed in percentage leaf area eaten by caterpillars and in leaf defense traits. The concentrations of foliar phenolic compounds negatively correlated with the percentage leaf area eaten by the caterpillars, but the results suggest a threshold, above which the concentration of each of the chemicals appeared to reduce WTC feeding, individually. Particularly, foliar oregonin concentration above 20 % leaf dry weight consistently appeared to reduce feeding by caterpillars. N availability had significant effects on red alder seedling total dry biomass and leaf N concentration. There was a clear trade-off between red alder seedling growth, and content of the phenolic compounds and leaf thickness, which supports the growth-differentiation balanced hypothesis in relation to resource availability. The concentration of oregonin varied during the growing season and there were no significant responses of any of the measured compounds to wounding. The results suggest that red alder foliar oregonin, condensed tannin and total phenolics are constitutive defenses and are not wound-induced. The effects of leaf total phenolic and condensed tannin concentrations on insect herbivory have been documented by past studies but the effects of oregonin concentration in red alder leaves on tent caterpillar feeding is a novel finding. / Graduate / 2020-04-18

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-06-09T18:33:27Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Bárbara Laine Ribeiro da Silva.pdf: 2635614 bytes, checksum: 8384212e8db84a27bc2b1fd6a579e7ad (MD5) / Made available in DSpace on 2017-06-09T18:33:27Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Bárbara Laine Ribeiro da Silva.pdf: 2635614 bytes, checksum: 8384212e8db84a27bc2b1fd6a579e7ad (MD5) Previous issue date: 2016-04-01 / CAPES / Em ambientes com clima semiárido, a sobrevivência das plantas depende da adaptação de características morfológicas, anatômicas e fisiológicas. O hábito das espécies e a estrutura do ambiente no qual a planta está inserida também determina sua sobrevivência em ambientes com condições ambientais limitantes, como a caatinga. No caso das espécies herbáceas, é necessário descobrir qual a principal limitação ambiental para o seu desenvolvimento, já que a maioria delas possui ciclo de vida restrito ao período de chuvas na região, bem como quais são as características desenvolvidas que permitem sua sobrevivência no ambiente. O trabalho avaliou características fisiológicas, anatômicas e morfológicas de três espécies herbáceas (Hyptis suaveolens L., Stachytarpheta sanguinea Mart. ex Schauer e Jacquemontia evolvuloides (Moric.) Meisn., em áreas de caatinga com 22, 44 e mais de 60 anos de regeneração, na Paraíba. Foram analisadas: área foliar; área foliar específica; espessura das epidermes, das cutículas, dos parênquimas e do mesofilo; densidade estomática e de tricomas; concentrações de clorofila a, clorofila b e carotenoides; potencial hídrico foliar, trocas gasosas, concentrações de compostos fenólicos totais, nitrogênio, potássio e fósforo. As três espécies apresentaram características anatômicas de folhas de sol, com estômatos e tricomas em ambas as faces foliares e maior concentração na face abaxial. J. evolvuloides apresentou mais características de locais ensolarados, com a menor área foliar específica na área em regeneração mais recente, maior espessura de epiderme e parênquima isobilateral. Algumas variações morfoanatômicas entre as áreas foram comuns entre as três espécies, como as maiores espessuras dos mesofilos e dos parênquimas na caatinga mais antiga que nas áreas com 22 e 44 anos em regeneração. No geral, H. suavoelens e S. sanguinea foram espécies mais plásticas que J. evolvuloides, com as maiores diferenças morfofisiológicas entre as áreas. J. evolvuloides demonstrou ser mais adaptada à baixa disponibilidade hídrica e à alta incidência luminosa. / In environments with semi-arid climate, the survival of plants depends on the adaptation of morphological, anatomical and physiological characteristics. The habit of the species and environmental structure in which the plant is inserted, also determines their survival in environments with limiting environmental conditions, such as the caatinga. In the case of herbaceous species, it is necessary to find out what is the main environmental limitations for its development, since most they have a life cycle restricted to the rainy season in the region, and what are the features developed to survival in the environment. This work determined the physiological, anatomical and morphological characteristics of three herbaceous species (Hyptis suaveolens L. Stachytarpheta sanguinea Mart. Ex Schauer and Jacquemontia evolvuloides (Moric.) Meisn., in areas of caatinga with 22, 44 and over 60 years of regeneration, in Paraiba state. Were analyzed the leaf area, specific leaf area, thickness of the epidermis, cuticle, parenchyma and mesophyll, the stomata and trichomes densities; concentrations of chlorophyll a, chlorophyll b and carotenoids, the leaf water potential, gas exchange, concentrations of total phenolic compounds, nitrogen, potassium and phosphorus. The three species have anatomical features of sun leaves with stomata and trichomes in both leaf surfaces and a greater concentration on the abaxial surface. J. evolvuloides showed more characteristics of sunny locations, with lowest specific leaf area in the most recent regeneration area, thickest epidermis and isobilateral parenchyma. Some morphoanatomical variations between the areas were common among the three species, such as the greater thicknesses of mesophyll and parenchyma in the oldest caatinga than in the areas with 22 and 44 years in regeneration. Overall, H. suavoelens and S. sanguinea were more plastic species than J. evolvuloides, with the largest morphophysiological differences between areas. J. evolvuloides proved to be more acclimatized to low water availability and high light incidence.

No description available.

Although a common plant response to environmental gradients, leaf trait plasticity is often uncharted in agroforestry systems. The objective of this study was to examine the effect of a i) local-scale gradient (light, nutrients) induced by shade tree diversity and ii) large-scale gradient (climato-edaphic) induced by altitude on coffee plant response on multiple agroforestry research farms in Costa Rica. Results show large variability of coffee traits: leaf photosynthetic rates, specific leaf area (SLA) and number of fruiting nodes deviate along both gradients. Mean SLA increased with increasing shade tree diversity. However, with increasing altitude, full sun coffee photosynthesized at higher rates than shaded coffee. Concurrently, other coffee leaf physiological and morphological traits differentiated between full sun and shaded coffee with increasing altitude. Results suggest soil moisture and light availability dominate environmental correlates to intraspecific coffee trait plasticity, providing insight to sources of coffee performance variability in monoculture and agroforestry systems.