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International audience; This work aims to improve our understanding of the resonance wood and to investigate the interactions between their physical-mechanical properties, natural variability, and the violin makers' ways of choosing their materials. In order to identify the luthiers' practices and opinions, a socio-technical survey was conducted. Physical, vibrational, and visual/structural characteristics of the resonance wood obtained from several provenances with a variety of quality grades were also determined. Finally, these two approaches were completed by a psychosensory evaluation to compare the measurements that we have conducted with the perception and qualification of wood by the violin makers. more...

We introduce a new non-destructive source of skeletochronological data with applications to species identification, associating disarticulated remains, assessing minimum number of individuals (MNI), and collection management of fossil snakes, but with potential implications for all bony vertebrates, extinct or extant. Study of a diverse sample of Recent henophidian snakes confirms that annual growth cycles (AGCs) visible on the surface of the vertebral zygantrum correspond to lines of arrested growth in osteohistological thin sections and accordingly reflect chronological age. None of the specimens considered here showed signs of remodelling of the zygantrum, suggesting that a complete, unaltered age record is preserved. We tested potential influences on AGCs with a single experimental organism, a maleBogertophis subocularis, that was raised at a controlled temperature and with constant access to mice and water. The conditions in which this individual was maintained, including that it had yet to live through a full reproductive cycle, enabled us to determine that its AGCs reflect only the annual solar cycle, and neither temperature, nor resource availability, nor energy diversion to gametogenesis could explain that it still exhibited lines of arrested growth. Moreover, growth lines in this specimen are deposited toward the end of the growth season in the fall, and not in the winter, during which this individual continued to feed and grow, even though this mid-latitude species would normally be hibernating and not growing. This suggests that growth lines are not caused by hibernation, but reflect the onset of a physiological cycle preparingBogertophis subocularisfor winter rest. That being said, hibernation and reproductive cycle could still influence the amount of time represented by an individual growth line. Growth-line number and AGC spacing-pattern, plus centrum length, are used to estimate MNI of the Early Eocene fossil snakeBoavus occidentaliscollected from the Willwood Formation over two field seasons during the late 19th century. We identified eight or nine individuals among specimens previously parcelled among two specimen lots collected during those expeditions. more...

In this note the authors report the first case of naturalization of the Malagasy smoke bush within Italian territory. Along with a description of the abiotic and biotic characteristics of the invaded site, the current demographic and dynamic trends of the detected population by means of growth-ring analysis was also assessed. Moreover, an overview on the history of its introduction in Europe is provided, underlining the key role played by the Mediterranean cities with respect to the acclimatization and spread of alien tropical and subtropical plants. Due to its low frequency under cultivation, the Malagasy smoke bush should not behave as an invader in the future; on the other hand, its ability to cover and smother neighbouring trees in very short times, make its spread within the whole Mediterranean area worth regular monitoring. more...

RESUMO Plantios comerciais de Ocotea porosa disponíveis para estudo são raros e por esse motivo devem ser usados como fonte de informação para se estabelecer o potencial de manejo da espécie. A recuperação do histórico do crescimento desses povoamentos para estruturação dos planos de manejo é possível com o uso da técnica da dendrocronologia e a análise de dados dendrométricos e morfométricos. O objetivo desse trabalho foi utilizar ferramentas de análise de povoamentos florestais aliadas aos estudos dendrocronológicos, para recuperar e sistematizar o desenvolvimento de povoamento não manejado. O trabalho foi conduzido em um povoamento não manejado de imbuia, com 44 anos, em Rio Negro - PR, na Estação Experimental da UFPR. Inferências do crescimento recuperado por dendrocronologia, e competição pela aplicação de metodologias como índice de abrangência e de projeção de copa mostraram resultados compatíveis na análise do povoamento, indicando necessidade de primeiro desbaste próximo aos 12 anos. Em função do pequeno número de árvores amostradas, os resultados não permitem generalizações definitivas, entretanto, são consistentes para estabelecer um protocolo para análise de povoamentos não manejados de Ocotea porosa,assim como de outras espécies. ABSTRACT Commercial plantations of Ocotea porosa available for studying are scarce and therefore should be used as a source of information to establish the potential for management of the species in plantations, even if these evaluations were not been held along the stand development. The recovery of the historical growth of these stands to optimize the management plans is possible by dendrochronology and by the analysis of morphometric and dendrometric data. The aim of this study was to use stand analysis tools, combined with the dendrochronological studies, to recover and to systematize the development of unmanaged stands. The study was conducted in an unmanaged stand ofOcotea porosa, with with 44 years of age in Rio Negro, PR state, in a UFPR research station. Growth inferences recovered by dendrochronology and the competition by the application of methodologies such as rate of coverage and crown cover rate showed consistent results in the analysis of population, indicating the need for a first thinning near 12 years old. Due to the small number of sampled trees, the results do not allow any definitive generalization. However, they are consistent to establish an analysis protocol for unmanaged stands of Ocotea porosa or other species. more...

Este manual tiene como objetivo describir los métodos para la determinación de la edad anual del estornino (Scomber colias, Gmelin, 1978). Las técnicas para la determinación de la edad en estructuras calcificadas de especies pelágicas y bentónicas (disección, preparación y métodos) en el área del ICES (aguas atlánticas europeas) se han descrito recientemente en un manual publicado tanto en inglés como en castellano (Villamor et al., 2015; 2016). Este nuevo manual que presentamos aquí se centra sólo, pero en mayor profundidad, en los criterios utilizados y estandarizados a nivel europeo para la interpretación de los anillos de crecimiento anual en los otolitos (lectura de otolitos) del estornino del Atlántico Nordeste. Este manual tiene como finalidad servir de referencia para los lectores de edad del estornino en los laboratorios del IEO y pretende también ser una guía para el entrenamiento de los nuevos participantes (lectores) en la determinación de la edad en los otolitos del estornino, para suplementar y complementar el entrenamiento que reciben del lector experto asignado para entrenarlos. También pretende ser una guía dinámica, que pueda cambiar a medida que sean introducidos nuevos criterios de interpretación tras ser evaluados y adoptados a nivel europeo. Este manual se basa en los últimos intercambios, talleres y publicaciones sobre la determinación de la edad del estornino (ICES, 2015; Navarro et al., 2015). También se hace referencia a la biología de la especie ya que es fundamental tener conocimiento de ella para poder interpretar los otolitos con mayor precisión. more...

Las Violetas Fossil Forest of the Salamanca Formation was a mixed forest of Paleocene age located in the Golfo San Jorge Basin, central Patagonia of Argentina, which includes conifers (previously studied), dicots and palms. In the present work, the dicot fossil woods outcropping in one of the fossiliferous levels (L3) of the Salamanca Formation are described, taxonomically assigned, and their affinities are discussed. They are three new species, including a new genus related to the Myrtaceae and Laurales. The complete fossiliferous assemblage is used to infer the climate and environment of the fossil forest. This assemblage represents a parautochtonous fossil plant association that lived either on the margins of channels or exposed bars in well-drained soils, probably tropical red-soils, close to their depositional setting (tidal channels and bars of an estuary). Warm and humid conditions and porous host-rocks favored the silicification of woods and pigmentation with Fe, resulting in yellow-orange and green fossil woods. We apply growth ring analysis to the conifer woods. For the dicots, wood anatomical characters influenced by the environment were analyzed, and the Vulnerability and Mesomorphy indices were used. These methods, comparisons with extant forests and the sedimentology, suggest that the Las Violetas Fossil Forest was an evergreen forest that developed under uniform growing seasons that ended abruptly, with an abundant water supply and high mean annual temperatures. Fil: Ruiz, Daniela Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Raigemborn, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina Fil: Brea, Mariana. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina Fil: Pujana, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina more...

This study has aims to determine the age and to estimate the growth parameters using scales of the species. Individuals of Piaractus mesopotamicus (Holmberg, 1887) used in this study were captured in the commercial fishery conducted in the region, along the year 2006. The model selected to express the growth of the species was the von Bertalanffy Sl= Sl∞*[1-exp-k(t-to)]. To determine if scales are suitable for studying the growth of pacu, we analyzed the relation between standard length (Sl) and the radius of the scales through linear regression. The period of annuli formation was determined analyzing the variations in the marginal increment and evaluating the consistency of the readings through the analysis of the coefficient of variations (CVs) for the average standard lengths of each age (number of rings) observed in the scales. The relationship between Ls of the fish and the radius of the scales showed that scales can be used to study the age and growth of P. mesopotamicus (R= 0.79). CVs were always below 20%, demonstrating the consistency of the readings. Annuli formation occurred in February, probably related to trophic migration that occurs in this month in the region. Equations that represents the growth in length obtained for P. mesopotamicus are Sl=50.00*[1-exp-0.18(t-(-3.00)] for males and Sl=59.23*[1-exp-0.14(t-(-3.36)] for females. The growth parameters obtained in this study were lower compared to other studies previously conducted for the same species and can related to overexploitation that species is submitted by fishing in the region. These values show also that females of pacu attain greater asymptotic length than males that growth faster. more...

We present preliminary results on age and growth of Dissostichus mawsoni for the third season (2015/16) of the Spanish research fishing in the 58.4.1 Division obtained for growth rings on otolith readings. It is included the growth parameters estimates by sex. Growth parameters obtained using length-age pair values are: L∞: 208.2, k: 0.074 and t0: 0.564 for females; L∞: 173, k: 0.089 and t0: -0.1771 for males; and L∞: 226.4, k: 0.05673 and t0: -0.745 all combined. Values differ with the previous estimates, and comparisons are made between seasons all seasons together as well as with the parameter values used in the Ross sea assessment. more...

This study is attempted to compare the number of rings and circular scales that are formed during various ages on Liza saliens. Sampling was carried out monthly during 2012-2013 using beach seine fishing nets. 102 specimens of different sizes were collected and transferred to the laboratory in boxes containing ice. The age of fish was determined by the number of annual rings as well as, the number of rings in each annual area. The distance between rings in each annual area was also measured. The results showed that the maximum growth was demonstrated in the first and second years. In the first year of life, the scale radius was nearly 2823.3±366.5(µm) which decreased to 1223.9±236.0(µm). The result indicated that 48 percentage of growth scales occurred in the first year and this value is only 21.8% in the second year. The number of growth rings in the annual regions decreased with increase in age. The result demonstrated that the average number of rings was 95.5±17.6 in the first life year of the fish. If you take into account the number of growth ring through years in comparison with the number of days in a year, it is clear that one ring was nearly made in four days in the first life year and it gradually reached 7.5, 15.9, 21.9 and 31.7 in the second, fourth and sixth years of life, respectively. One ring was approximately made in each month at higher ages. more...

Tundra shrubs are slow-growing species limited by low air temperature and scarce nutrient availability. However, shrub expansion has been widely observed in the Arctic during the last decades and attributed to climate warming. Shift in shrub growth, wood structure and abundance affects the surface albedo and permafrost thawing and these changes may feedback to climate. Despite the importance of shrub–climate feedbacks, uncertainties about shrub growth sensitivity to climate remain. Here, we explored the indirect effects of climate warming on shrub growth (vertical and radial), bark thickness, and bark investment in four arctic shrub species. We combined a field experiment addressing two suggested growth drivers – thawing depth and nutrient availability – with dendroecology in a Siberian tundra ecosystem. We used heating cables to increase the thawing depth. To enhance the nutrient availability, we fertilized the surface soil layers. We found that shrub growth was mainly limited by nutrient availability, as indicated by the fertilization treatment effects on shrub growth ring widths. We also found a bark thickness decrease with the combined soil heating and nutrient addition treatment and a negative correlation between bark investment and growth rate for two of the species. These findings suggest that tundra shrubs, especially deciduous species, will grow faster and taller driven by an increasing nutrient availability in the surface soil layers. However, shrubs might become more vulnerable to pests, herbivory, and climate extremes, such as frost or drought events, due to thinner bark and lower bark investment. Using dendroecological approaches in field experiments simulating projected climate scenarios for the Arctic, and an increasing number of study species and locations will reduce uncertainties related to shrub growth sensitivity to climate and other processes driving shrub dynamics. more...

11 pages, 6 figures, 4 tables, supplementary material https://dx.doi.org/10.1016/j.dsr.2016.03.007, Antarctic benthic communities have long been regarded as relicts of the past, since they have developed in a very stable environment and are formed by slow-growing and extraordinary long-lived organisms. However, little is known about the life history traits of gorgonian species, which are considered key components of the Antarctic benthos. In this study, age, Radial Growth Rates (RGR) and skeletal composition of Thouarella variabilis, Fannyella abies and Fannyella rossii colonies (Octocorallia, Primnoidae) that inhabit Antarctic shelf waters were examined. The radioisotopes C and Pb used for dating revealed that these colonies are long-lived, with ages spanning from 50 to 1100 years, thus confirming the archaic character of the Antarctic ecosystem. Some RGR obtained are among the lowest rates ever reported for primnoid species and gorgonians as a whole, with Thouarella species showing rates of 5.08 μm yr. Growth ring deposition seemed to occur every 2-3 years on average, although this result cannot be confirmed. Irregularities in the growth rings could be observed under the Scanning Electron Microscope (SEM) as fluctuations in the skeletal composition, which may be indicative of changes in the environmental conditions, most possibly primary production, This research was funded by ECOWED Project (CTM2012-39350-C02-01) more...

Age and growth parameters of cachara Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae) (males and females) were estimated through the analysis of growth rings in spines of pectoral fins. Fish were collected from January to December 2007, in the area directly influenced by the Aproveitamento Múltiplo de Manso (APM Manso) and in the Cuiabá River (upper parts of the Pantanal). The maximum number of growth rings was seven for males, and eight, for females. The analysis of temporal variations in mean marginal increment showed that rings found in the spines were formed annually, in December. Growth rings were associated to spawning (in the study region from November to March) of the species. The growth curve in length was obtained by the von Bertalanffy model adjusted by the Ford-Walford transformation. The equations are: Ls = 72.7*[1-e-0.44(t+1.5974)] for males, and Ls = 84.5*[1-e-0.33(t+2.0943)] for females. The equations that describe the growth curve in weight are: Wt = 4991.61*[1-e-0.44 (t+1.5974] 2.70 for males and Wt = 7503.17*[1-e-0.33 (t+2.0943] 2.99 for females. A idade e os parâmetros de crescimento de machos e fêmeas do cachara, Pseudoplastystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae), coletados de janeiro a dezembro de 2007, na área de influencia do Aproveitamento Múltiplo de Manso (APM Manso) e rio Cuiabá (parte superior do pantanal), foram estimados através das marcas de aposição (anéis) observadas nos acúleos das nadadeiras peitorais. O número máximo de anéis encontrados foi sete para os machos e oito para as fêmeas. Os anéis encontrados nos acúleos foram anuais e formados em dezembro, como observado através da análise da variação temporal do incremento marginal médio. Possivelmente estes estão relacionados com a época de reprodução para a espécie na área (novembro a março). A curva de crescimento em comprimento foi obtida pelo modelo de von Bertalanffy, ajustada pela transformação Ford-Walford. As equações são: Cp = 72,7*[1-e-0,44(t+1,5974)] para machos e Cp = 84,5*[1-e-0,33(t+2,0943)] para fêmeas. As equações que descrevem a curva de crescimento em peso são: Pt = 4991,61*[1-e-0,44(t+1,5974)]2,70 para machos e Pt = 7503,17*[1-e-0,33(t+2,0943)]2,99 para fêmeas. more...

There is a great demand for wood within tropical natural forests and a scarcity of available data to carry out a management program. It is of great importance, therefore, that growth ring information is being enhanced. The Pantanal of Nhecolândia, sub-region of Pantanal Mato-grossense, may be viewed as one of these regions. Its natural forests are systematically cut to be used as solid wood or fuel, or replaced by cultivated pastures. Peculiar climatic and soil factors of Nhecolandia induce the formation of annual growth rings. This work aims at determining the radial increments of Anadenanthera colubrina var. cebil and Tabebuia impetiginosa by growth ring analysis. Disks from eight trees of Anadenanthera colubrina var. cebil and six of Tabebuia impetiginosa were collected, in July 1996, in Nhumirim Farm, Embrapa Pantanal, located in Nhecolandia sub-region. The trees of Anadenanthera colubrina var. cebil and Tabebuia impetiginosa were 14 to 30 and 15 to 30 years old, respectively. Diameter increment varied from 5.4 to 8.0 mm/year for Anadenanthera colubrina var. cebil and from 4.8 to 11.6 mm/year for Tabebuia impetiginosa. The average estimated time for both species to reach a diameter of 40 cm was 55 years. RESUMO O uso de informações obtidas por estudos com anéis de crescimento é cada vez mais freqüente e são muito importantes para florestas naturais tropicais onde a demanda por madeira é grande, mas geralmente não existem dados disponíveis sobre o crescimento das espécies arbóreas para a estruturação de programas de manejo. O Pantanal da Nhecolândia, sub-região do Pantanal Mato-Grossense, pode ser visto como uma dessas regiões onde as florestas naturais são sistematicamente cortadas para extração de madeira, ou para implantação de pastagens cultivadas. Fatores climáticos e edáficos, característicos do Pantanal, sub-região da Nhecolândia, induzem a formação de anéis anuais de crescimento. Objetivou-se, com este trabalho, determinar a idade e os incrementos radiais de Anadenanthera colubrina var. cebil e Tabebuia impetiginosa, pela análise dos anéis de crescimento. Discos de oito árvores de Anadenanthera colubrina var. cebil e seis de Tabebuia impetiginosa foram coletados em julho de 1996, na fazenda Nhumirim, de propriedade da Embrapa Pantanal, localizada na sub-região da Nhecolândia. As árvores de Anadenanthera colubrina var. cebil e Tabebuia impetiginosa apresentavam 14 a 30 e 15 a 30 anos respectivamente, com crescimento anual médio, em diâmetro a 1,3 m do solo, variando de 5,4 a 8,0 mm em Anadenanthera colubrina var. cebil e de 4,8 a 11,6 mm em Tabebuia impetiginosa. O tempo médio para Anadenanthera colubrina var. cebil e Tabebuia impetiginosa atingirem 40 cm de diâmetro foi estimado em, no mínimo, 55 anos. more...

The goal of the present study was to find a pattern regarding wood anatomical features for the Araucaria Forest. For that, we studied the wood anatomy of 17 tree species characteristics of this forest formation of Southern Brazil. The species were selected based on the amplified importance value. Wood samples of three individuals per species were collected and prepared according to standard wood anatomical techniques. Most of the species can be grouped according to the presence of the following features: visible growth rings, diffuse porosity, absence of any typical vessel arrangement, simple perforation plate, simple to diminute bordered pits in fibers, little axial parenchyma, heterogeneous rays. The Grouping Analysis of qualitative and quantitative characters groups the species together, but two are distinct from the others: Cinnamodendron dinisii and Roupala montana. Principal Component Analysis explained 69 % of the total variance, influenced by rays height and width, vessel element and fiber length, separating Cinnamodendron dinisii and Roupala montana from the others. Results corroborated ecological wood anatomical patterns observed for other species in other tropical and subtropical vegetation formations occurring in higher altitudes and latitudes, where the species can be characterized by the presence of visible growth rings, predominantly solitary vessels, simple perforation plates and little axial parenchyma. Se presenta el estudio anatómico de la madera de 17 especies de árboles características de una formación de bosque de araucaria, en el sur de Brasil. Se colectaron 17 especies, basado en el valor de importancia ampliado. Muestras de madera de tres individuos por especie fueron recolectadas, y preparadas de acuerdo con técnicas usuales empleadas en anatomía de la madera. La mayoría de las especies se pueden agrupar para la presencia de las siguientes características: anillos crecimiento visibles, porosidad difusa, los vasos no presentaron patrones específicos de agrupamientos, platina de perforación simples, punteaduras diminutas a bordeadas en las fibras, poco parénquima axial, radios heterogéneos. El análisis de agrupamiento de los caracteres cualitativos y cuantitativos de las especies se las agruparon juntas, pero dos son distintos de los demás: Cinnamodendron dinnisii y Roupala montana. El análisis de componentes principales explicó 69 % de la varianza total, influido por la altura y ancho de los radios, la longitud de los elementos de vasos y de las fibras, separando Cinnamodendron dennisii y Roupala montana de los demás. Los resultados corroboraron los patrones anatómicos ecológicos de la madera observados en otras formaciones vegetales tropicales y subtropicales, en mayor altitud y latitud. more...

Background and Aims In Costa Rica, coffee (Coffea arabica) plants are often grown in agroforests. However, it is not known if shade-inducing trees reduce coffee plant biomass through root competition, and hence alter overall net primary productivity (NPP). We estimated biomass and NPP at the stand level, taking into account deep roots and the position of plants with regard to trees. Methods Stem growth and root biomass, turnover and decomposition were measured in mixed coffee/tree (Erythrina poeppigiana) plantations. Growth ring width and number at the stem base were estimated along with stem basal area on a range of plant sizes. Root biomass and fine root density were measured in trenches to a depth of 4 m. To take into account the below-ground heterogeneity of the agroforestry system, fine root turnover was measured by sequential soil coring (to a depth of 30 cm) over 1 year and at different locations (in full sun or under trees and in rows/inter-rows). Allometric relationships were used to calculate NPP of perennial components, which was then scaled up to the stand level. Key Results Annual ring width at the stem base increased up to 2·5 mm yr−1 with plant age (over a 44-year period). Nearly all (92 %) coffee root biomass was located in the top 1·5 m, and only 8 % from 1·5 m to a depth of 4 m. Perennial woody root biomass was 16 t ha−1 and NPP of perennial roots was 1·3 t ha−1 yr−1. Fine root biomass (0–30 cm) was two-fold higher in the row compared with between rows. Fine root biomass was 2·29 t ha−1 (12 % of total root biomass) and NPP of fine roots was 2·96 t ha−1 yr−1 (69 % of total root NPP). Fine root turnover was 1·3 yr−1 and lifespan was 0·8 years. Conclusions Coffee root systems comprised 49 % of the total plant biomass; such a high ratio is possibly a consequence of shoot pruning. There was no significant effect of trees on coffee fine root biomass, suggesting that coffee root systems are very competitive in the topsoil. (Resume d'auteur) more...

International audience; This chapter focuses on trees and their responses to flooding in large fresh water flood-pulsed ecosystems. The regularity and predictability of the flood pulse has allowed for the development of adaptations by which a large number of tree species are able to grow in ecosystems subjected to seasonally inundated sites. By comparing diversity and tree responses in four floodplain ecosystems on different continents, we attempt to improve our understanding of the factors influencing spatial distribution of plants, diversity of species and adaptations and thus contribute to our knowledge of tropical wetland ecology. In this way, we hope to assist in the successful restoration of degraded floodplains and promote the sustainable use and conservation of these highly valuable ecosystems. more...

The goal of the present study was to find a pattern regarding wood anatomical features for the Araucaria Forest. For that, we studied the wood anatomy of 17 tree species characteristics of this forest formation of Southern Brazil. The species were selected based on the amplified importance value. Wood samples of three individuals per species were collected and prepared according to standard wood anatomical techniques. Most of the species can be grouped according to the presence of the following features: visible growth rings, diffuse porosity, absence of any typical vessel arrangement, simple perforation plate, simple to diminute bordered pits in fibers, little axial parenchyma, heterogeneous rays. The Grouping Analysis of qualitative and quantitative characters groups the species together, but two are distinct from the others: Cinnamodendron dinisii and Roupala montana. Principal Component Analysis explained 69 % of the total variance, influenced by rays height and width, vessel element and fiber length, separating Cinnamodendron dinisii and Roupala montana from the others. Results corroborated ecological wood anatomical patterns observed for other species in other tropical and subtropical vegetation formations occurring in higher altitudes and latitudes, where the species can be characterized by the presence of visible growth rings, predominantly solitary vessels, simple perforation plates and little axial parenchyma., Se presenta el estudio anatómico de la madera de 17 especies de árboles características de una formación de bosque de araucaria, en el sur de Brasil. Se colectaron 17 especies, basado en el valor de importancia ampliado. Muestras de madera de tres individuos por especie fueron recolectadas, y preparadas de acuerdo con técnicas usuales empleadas en anatomía de la madera. La mayoría de las especies se pueden agrupar para la presencia de las siguientes características: anillos crecimiento visibles, porosidad difusa, los vasos no presentaron patrones específicos de agrupamientos, platina de perforación simples, punteaduras diminutas a bordeadas en las fibras, poco parénquima axial, radios heterogéneos. El análisis de agrupamiento de los caracteres cualitativos y cuantitativos de las especies se las agruparon juntas, pero dos son distintos de los demás: Cinnamodendron dinnisii y Roupala montana. El análisis de componentes principales explicó 69 % de la varianza total, influido por la altura y ancho de los radios, la longitud de los elementos de vasos y de las fibras, separando Cinnamodendron dennisii y Roupala montana de los demás. Los resultados corroboraron los patrones anatómicos ecológicos de la madera observados en otras formaciones vegetales tropicales y subtropicales, en mayor altitud y latitud. more...

The tree Piptadenia gonoachantha is widely used in forestry and in forest restoration projects, which require methods for evaluating tree growth. Long-term studies are necessary to determine patterns and detect changes in species growth rhythms. Tree ring analysis provides a precise method for determining age and documenting long-term growth trends in tropical tree species. The present study evaluated the periodicity of tree ring formation and radial growth dynamics of P. gonoachantha from a population of known age in the Poço das Antas Biological Reserve. Two radii from six trees were sampled using non-destructive methods. Tree rings were counted and measured to estimate age and to calculate diametric increment. All samples had 16 tree rings, which matched the known plantation age and confirmed the annual formation of rings. The individuals sampled had a mean annual diametric increment of 9.5 mm / year. Results showed a trend towards decreasing growth rate with increasing age. Individuals of P. gonoachantha in Ombrophilous Dense Forest produce annual tree rings, which holds potential for future dendroecological studies. more...

The formation of annual growth rings has been confirmed for several mangrove species in the last decade, among which is the Rhizophora mangle. However, the record of annual rings for this species was made in a region with high hydric seasonality, a widely recognized induction factor of annual rings in tropical species. In this sense, the present study aimed to verify the occurrence of annual growth rings in R. mangle in the mangroves of Guaratiba (Rio de Janeiro, Southeastern Brazil), a region with low hydric seasonality. For this purpose, the crossdating technique was applied in ten trees collected with known age (seven years). The growth rings are characterized by alternating layers of low vessel density (earlywood) and high vessel density (latewood). Multiple regression analysis indicated that growth rings width variation is driven by precipitation, water surplus, water deficit and water storage. Crossdating analysis confirmed the existence of annual growth rings in the R. mangle in Guaratiba. This discovery in a region with low hydric seasonality increases the dendrocronological potential of this species and suggests the importance of biological factors (eg. phenological behavior) as complementary inductors for the formation of growth rings in this species. RESUMO A formação de anéis de crescimento anuais tem sido confirmada para diversas espécies de mangue na última década, dentre as quais Rhizophora mangle. Contudo, o registro de anéis anuais para esta espécie foi feito em região com alta sazonalidade hídrica, um fator de indução de anéis anuais em espécies tropicais amplamente reconhecido. Nesse sentido, o presente estudo teve como objetivo verificar a ocorrência de anéis de crescimento anuais em R. mangle nos manguezais de Guaratiba (Rio de Janeiro, sudeste do Brasil), região com baixa sazonalidade hídrica. Para isso, a técnica de datação cruzada foi aplicada em dez árvores coletadas com idade conhecida (sete anos). Os anéis de crescimento são caracterizados pela alternância entre uma camada com baixa densidade de vasos (lenho inicial) e outra com alta densidade de vasos (lenho tardio). A análise de regressão múltipla indicou que o padrão de variação de largura dos anéis de crescimento é determinado por precipitação, excedente hídrico, déficit hídrico e armazenamento hídrico. A análise de datação cruzada confirmou a existência de anéis de crescimento anuais no lenho de R. mangle em Guaratiba. Essa descoberta em região com sazonalidade hídrica pouco pronunciada aumenta o potencial dendrocronológico desta espécie e sugere a influência de outros fatores (ex. comportamento fenológico) como indutores complementares para a formação dos seus anéis de crescimento desta espécie. more...

National audience

A identificação do ritmo de crescimento das variáveis dendrométricas de espécies florestais com o uso da análise de tronco é rápida, eficiente e de grande importância na tomada de decisões para o manejador florestal. Sendo assim, objetivou-se neste trabalho analisar a evolução das curvas de produção, Incremento Médio Anual (IMA) e Incremento Corrente Anual (ICA) da altura, diâmetro, área transversal e volume individual da Bracatinga (Mimosa scabrella), em diferentes classes de sítio, bem como, ajustar modelos matemáticos para expressar a evolução dessas variáveis, ao longo dos anos. A base de dados proveio da análise completa de tronco de 29 árvores, coletadas na região metropolitana de Curitiba, com idades variando de sete a 18 anos, distribuídas em três classes de sítio. Após as medições e processamento básico dos dados, ajustaram-se seis modelos matemáticos conhecidos na literatura, para cada uma das quatro variáveis dendrométricas em análise, independentemente para cada sítio. O melhor modelo foi escolhido com base no coeficiente de determinação ajustado (R²aj), erro padrão de estimativa em percentagem (Syx%) e análise gráfica de resíduos. Os resultados mostraram que o modelo de Chapman-Richards foi o de melhor ajuste para quase todas as variáveis em análise dentro dos três sítios. Verificou-se, também, que a ordem de culminação do incremento corrente anual seguiu a ordem cronológica esperada, isto é, primeiro a altura, seguida pelo diâmetro, área transversal e, por último, o volume, em todos os sítios. The identification of the growth rhythm of the dendrometric variables of forest species with the use of stem analysis is quick, efficient and of great importance in the decision making by forest managers. Thus, the objectives of this research were to analyze the annual evolution of the yield curves, Mean Annual Increment (MAI) and Current Annual Increment (CAI) in height, diameter, cross sectional area and volume of individual Mimosa scabrellaBenth (Bracatinga) in different site classes, and also, to fit mathematical models to express the evolution of these variables over the years. The database came from complete stem analysis of 29 Mimosa scabrella trees collected in the metropolitan region of Curitiba, with ages ranging from seven to 18 years, distributed in three site classes. After the measurements and basic data processing, six mathematical models were adjusted for each one of the four dendrometric variables, independently for each site. The best model was chosen based on the adjusted coefficient of determination (R²aj), relative standard error of estimate (Syx%) and residual graphic analysis. The results showed that the Chapman-Richards model presented the best fitting for almost all analyzed variables in all three sites. It was also verified that the culmination order of the current annual increment followed the expected chronological order, that is, first height, then diameter, cross sectional area, and finally, volume, in all the sites. more...

The indirect validation in increments (rings) counting by a precision analysis allowed to determine the daily deposition pattern in whitemouth croaker (Micropogonias furnieri) otoliths during the larval and early juvenile stages. To compare the number of rings in each individual both sagittae otoliths (n= 71) and the readings by two independents readers (n= 27) were used. A slight variation of the optic focus allowed to eliminate sub-daily increments and obtain the best reading plane of the daily growth pattern. Between the 28th and 35th increment, approximately, the growing otoliths showed a rather diffuse zone where accessory nuclei around the main nucleus appeared. From the 35th increment onwards another deposition pattern markedly different from that of the accessory nuclei was noticed. The slopes of the linear regressions fitted between the otoliths of the pair and between the ones observed on the same otolith by the independent readers did not show significant differences with respect to 1. The analysis replicated and the intervention of two skilled independent readers constituted a consistent method to identify the daily deposition pattern in otoliths of the species larvae and early juveniles. Fil: Braverman, Mara Silvia. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Brown, Daniel Roberto. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina Fil: Acha, Eduardo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina more...

O Schizolobium parahyba (Vell.) Blake, popularmente conhecido por “guapuruvu”, apresenta anéis de crescimento distintos, evidenciados por maior espessamento de suas paredes no lenho tardio e pela presença de parênquima em faixa marginal. Neste contexto, o objetivo deste estudo foi construir a cronologia dos anéis de crescimento de árvores de S. parahyba de ocorrência na ReBio de Tinguá, RJ, visando gerar conhecimento sobre a dinâmica de crescimento da espécie, bem como sobre a sensibilidade da formação dos anéis de crescimento por fatores climáticos. Das 30 árvores selecionadas foram coletadas quatro amostras radiais do tronco, utilizando-se uma sonda Pressler. As amostras passaram por polimento mecânico para melhor visualização dos anéis de crescimento e posterior delimitação e mensuração da largura deles. Para verificar a sincronização da largura dos anéis de crescimento e gerar uma série mestra da cronologia para a espécie, foi utilizado o programa estatístico COFECHA. A espécie apresenta ótimo potencial dendrocronológico, confirmado por elevada correlação da largura dos anéis de crescimento dentre e entre árvores. Além disso, exibe elevado coeficiente de sensibilidade média, que demonstra resposta às variações ambientais. O crescimento da espécie é correlacionado com a precipitação na estação seca. The Schizolobium parahyba, popularly known as “guapuruvu”, has distinct growth rings evidenced by increased thickening of the walls in the late wood and the presence of marginal parenchyma bands. In this context, the aim of this study was to construct a chronology of the growth rings of S. parahybatrees, occurring in Biological Reserve Tinguá, RJ, in order to generate knowledge about the growth dynamic of the species, as well as the sensitivity of the formation of growth rings by climatic factors. From the 30 selected trees, four radial trunk samples were collected using a Pressler borer. The samples suffered mechanical polishing for better visualization of the growth rings and subsequent delineation and measurement of the width of these rings. The statistical program COFECHA was used to check the synchronization of the width of growth rings and generate a series of master chronology of the specie. The species has a great dendrochronological potential, which was confirmed by a high correlation of the width of growth rings within and between trees. Moreover, the species has a high average sensitivity coefficient, which shows a response to environmental variations. The growth of the species is correlated with precipitation in the dry season. more...

Increase of nitrogen depositions, as oxidized (NOx) and reduced (NHx) compounds, has important implications on ecosystem nitrogen cycle. NOx comes predominantly from fossil fuel combustion in car engines and industrial processes, while agricultural activities (cattle farming, fertilizations) are the main sources for NHx emissions. Such fertilisations could stimulate growth and, therefore, productivity of forests, especially in temperate forests, where nitrogen is a limiting factor. On the other hand an excess of nitrogen can lead to an acidification of the soil and have a negative impact on the microbial fauna and structure of plants. NOx and NHx depositions can be separated with the help of stable isotopes with different 15N-values reported for NOx originating from combustion sources. Consequently it was observed that the nitrogen isotopic composition of the vegetation reflects the isotopic signature of nitrogen sources. Our preliminary results on needles of Norway spruce trees exposed to NOx emissions along a transect perpendicular to a highway close to Faido and Brittnau show a clear isotopic enrichment in 15N in trees growing closer to traffic pollution, indicating an uptake of atmospheric nitrogen by stomatal pathway. Carbon and oxygen isotopic composition measured in tree rings reveals the physiological response in plants. Trees more exposed to air pollution from traffic show an increase in δ13C and δ18O in tree rings, since mid sixties next to Erstfeld. This could mean a higher photosynthetic activity, enhanced by NOx traffic emissions, under low or not changed stomatal conductance. Our results confirm that stable isotopes of carbon, oxygen and nitrogen measured in needles and tree rings represent an important tool to monitor the impact of NOx load on tree physiology. more...

Veeneiken zijn (veen)restanten van eiken uit moerasbossen op laagveen. Ze vormen interessant materiaal voor dendrochronologisch onderzoek. Er is voor deze eiken inmiddels een chronologie opgebouwd over de jaren 3600 BC tot 563 AD. Onderzoek aan veeneiken in Nederland en Noordwest-Europa en aan twee (pre)historische moerasbossen in Nederland (locaties Zwolle en Ypenburg) wordt gebruikt voor landschap- en klimaatreconstructie more...

Submitted by Anna Barbara Alves Beraldine (annabarbara@unisinos.br) on 2021-09-28T13:43:03Z No. of bitstreams: 1 Gabriela de Fátima dos Reis Avila_.pdf: 4409831 bytes, checksum: f00b730524adb3d500d0c02e7e915e88 (MD5) Made available in DSpace on 2021-09-28T13:43:03Z (GMT). No. of bitstreams: 1 Gabriela de Fátima dos Reis Avila_.pdf: 4409831 bytes, checksum: f00b730524adb3d500d0c02e7e915e88 (MD5) Previous issue date: 2015-03-26 CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Anéis de crescimento são estruturas anatômicas, formadas no xilema secundário de plantas, que demarcam ciclos de crescimento e dormência em resposta a regimes climáticos sazonais. Visto que cada anel corresponde a um ciclo anual de crescimento e que variam suas características em função das condições do meio físico e biótico, essas estruturas são registros históricos únicos, com alta resolução e extensão temporal sobre mudanças ambientais. A dendrocronologia – ciência que investiga anéis de crescimento em plantas – é ainda incipiente em ecossistemas tropicais, dado seu avanço em regiões temperadas, e deve ser desenvolvida, uma vez que provém informações sobre autoecologia, ecologia florestal e climatologia, bases para o manejo da biodiversidade tropical. Reconhecer espécies com anéis de crescimento anatomicamente visíveis no xilema e sensíveis a flutuações climáticas é o passo primordial para o desenvolvimento da dendrocronologia. Nessa dissertação eu reviso e desenvolvo estudos dendrocronológicos com espécies neotropicais da família Lauraceae, principalmente em remanescentes florestais do sul da Mata Atlântica, um dos hotspots mundiais de biodiversidade. Foco meus esforços em Lauraceae devido à importância ecológica e fisionômica das espécies para as florestas úmidas neotropicais. Informação sobre anéis de crescimento está amplamente disponível na literatura, principalmente em estudos de anatomia da madeira. É notável que grande parte das lauráceas forma anéis de crescimento, em diversos ecossistemas (139 das 156 espécies levantadas em revisão bibliográfica). Com o intuito de facilitar estudos futuros e o reconhecimento dos anéis, apresento uma lista de 156 espécies descritas pela aparência dos anéis e realizo descrições anatômicas de outras 14 frequentes no sul da Mata Atlântica. Estudando séries temporais de largura de anéis de crescimento, verifiquei que Ocotea puclhella, Cinnamomum glaziovii e Ocotea elegans, espécies que ocorrem em regiões montanas subtropicais do Brasil possuem tendências comuns de crescimento entre os indivíduos (sincronismo) e são sensíveis a variações climáticas relacionadas tanto à temperatura quanto à precipitação. Esses resultados contribuem para o avanço da dendrocronologia neotropical, contribuindo para o melhor entendimento sobre as características dos anéis de crescimento de uma das mais importantes famílias botânicas em regiões tropicais. Tree-rings are anatomical structures formed in the secondary xylem of wood plants. These structures delimit the growth cycles and dormancy as response to seasonal climate regimes. Since each ring correspond to one annual growth cycle varying their features as result of physical and biotic conditions, these structures are unique historical records with high resolution and temporal depth reflecting environmental changes. The dendrochronology – science that investigates tree-rings in wood plants – is incipient in tropical ecosystems, taking into account its advancement in temperate zones, and should be developed in tropical zones to provide clearer information about autoecology, forest ecology and climatology, base to tropical biodiversity management. To recognize species forming visible tree-rings in their xylems and that are sensible to climatic fluctuations is the first and prime step to development of dendrochronology. In this Master Dissertation I revise and perform dendrochronological analysis in the neotropical Lauraceae family, mainly in remaining forests of Southern rain forest of Brazil, a hotspot of biodiversity. I focus my efforts in Lauraceae family due to ecological and physiognomic importance of their species to neotropical rain forests. Information about tree-rings are widely available in the scientific literature, especially in the anatomical wood researches. Most species of Lauraceae family form tree-rings in different ecosystems (139 of 156 revised species). In order to facilitate future studies and the recognition of tree-rings I present 156 species described by tree-ring appearance plus 14 other frequent species in Southern rain forest. With temporal series of tree-ring width I verify that Ocotea pulchella, Cinnamomum glaziovii and Ocotea elegans, species from subtropical montane regions of Brazil, have the same growth tendency between individuals (synchronism). Moreover, are sensible to climate variations mainly related to temperature and precipitation. The findings of this dissertation are essential to contribute to development of neotropical dendrochronology, providing a better understanding about tree-rings features of one of the most important families in the tropical regions. more...

MARKERS INSIDE WOOD – TREE RINGS AS ARCHIVES OF INSECT OUTBREAKS, DRIFT-SAND DYNAMICS AND SPRING FLOODING Trees are long-living organisms that record ecologically relevant information in their xylem that can be accessed by dendrochronology, the study of tree rings. Specific environmental events like frost, fire, floods, burial or wounding may drastically alter the anatomy of tree rings and consequently may leave markers inside trees. These wood-anatomical markers have shown a high potential for studying past environmental events with an annual or even intra-annual temporal resolution. In this thesis, the temporal resolution of wood-anatomical markers was studied to date wounds made by invasive Anoplophora beetles. In addition, the accuracy of dating drift-sand dynamics and spring flooding events was studied using wood-anatomical changes, which were expected to occur after drastic changes in the stem and root environment. It was hypothesised that all these wood-anatomical markers can be used with an intra-annual resolution. Field studies in combination with experiments were used to study tree growth and the formation of wood-anatomical markers in Japanese maple (Acer palmatum Thunb.) and pedunculate oak (Quercus robur L.). It was shown that wounds in Japanese maple can be assigned to three different phases related to tree-ring development: (1) wounds that originated during dormancy are located at the tree-ring boundary; (2) wounds that originated during the growing season are located within the tree ring. If wound-xylem formation was observed locally around the wound (3), it could either imply that the wound originated at the very end of the growing season or just before the onset of radial growth or during dormancy when temperature was high. Dating wounds caused by the formation of exit holes has proved to be very significant in fighting invasive insect outbreaks. By pinpointing the exact year and season when Anoplophora beetles emerged, it can be substantiated whether exit holes in imported trees were formed at the location of import. This knowledge can subsequently be used to draw up customised eradication measures and allocate proper surveillance plans and population dynamics can be reconstructed. Living trees in drift-sand areas may contain burial or exposure signals even if the sand under which they were buried has long since disappeared. Anatomical changes in pedunculate oak trees due to burial are not a result of physical changes in the stem environment that directly affect the cambium. Instead they are most likely the result of adventitious root formation that transforms lower parts of the stem into root, and concomitantly induces a change from stem to root anatomy. As the formation of a wood-anatomical marker caused by burial can be delayed by many years or might be entirely absent, depending on the formation of adventitious root formation, its presence only allows for an estimate on minimum burial age. Flood rings containing anomalously small earlywood vessels in pedunculate oak are formed in response to spring flooding within a narrow time window related to cambial phenology. They can be induced if a flooding event has occurred for at least two weeks during spring. The extreme reduction in vessel size is a consequence of a delay in vessel formation due to anoxic conditions related to flooding. Flood rings however, provide only limited information on the duration of flooding, as the flooding may have lasted for months (during winter) before it is recorded. It is concluded that the origin of wood-anatomical markers largely determines the temporal resolution. Markers induced by wounding or flooding show a high intra-annual temporal resolution and immediate effect on tree functioning, whereas burial might not be recorded three years after the triggering events. The different wood-anatomical markers addressed in this thesis illustrate the relevance of studying the mechanism behind the formation of markers for correct interpretation of the specific triggering factor as well as their temporal resolution. Only with this knowledge it becomes possible to reliably use wood-anatomical markers as archives to understand and reconstruct dynamics in geomorphic, entomologic, pathogenic or climatic factors. more...

Boktorren die uitvliegen laten sporen na in hun kraamkamer. Promovendus Paul Copini leest die sporen in jaarringen van bomen en kan zeggen wanneer de boktor is geboren. Een oordeel met gewicht.

MARKERS INSIDE WOOD – TREE RINGS AS ARCHIVES OF INSECT OUTBREAKS, DRIFT-SAND DYNAMICS AND SPRING FLOODING Trees are long-living organisms that record ecologically relevant information in their xylem that can be accessed by dendrochronology, the study of tree rings. Specific environmental events like frost, fire, floods, burial or wounding may drastically alter the anatomy of tree rings and consequently may leave markers inside trees. These wood-anatomical markers have shown a high potential for studying past environmental events with an annual or even intra-annual temporal resolution. In this thesis, the temporal resolution of wood-anatomical markers was studied to date wounds made by invasive Anoplophora beetles. In addition, the accuracy of dating drift-sand dynamics and spring flooding events was studied using wood-anatomical changes, which were expected to occur after drastic changes in the stem and root environment. It was hypothesised that all these wood-anatomical markers can be used with an intra-annual resolution. Field studies in combination with experiments were used to study tree growth and the formation of wood-anatomical markers in Japanese maple (Acer palmatum Thunb.) and pedunculate oak (Quercus robur L.). It was shown that wounds in Japanese maple can be assigned to three different phases related to tree-ring development: (1) wounds that originated during dormancy are located at the tree-ring boundary; (2) wounds that originated during the growing season are located within the tree ring. If wound-xylem formation was observed locally around the wound (3), it could either imply that the wound originated at the very end of the growing season or just before the onset of radial growth or during dormancy when temperature was high. Dating wounds caused by the formation of exit holes has proved to be very significant in fighting invasive insect outbreaks. By pinpointing the exact year and season when Anoplophora beetles emerged, it can be substantiated whether exit holes in imported trees were formed at the location of import. This knowledge can subsequently be used to draw up customised eradication measures and allocate proper surveillance plans and population dynamics can be reconstructed. Living trees in drift-sand areas may contain burial or exposure signals even if the sand under which they were buried has long since disappeared. Anatomical changes in pedunculate oak trees due to burial are not a result of physical changes in the stem environment that directly affect the cambium. Instead they are most likely the result of adventitious root formation that transforms lower parts of the stem into root, and concomitantly induces a change from stem to root anatomy. As the formation of a wood-anatomical marker caused by burial can be delayed by many years or might be entirely absent, depending on the formation of adventitious root formation, its presence only allows for an estimate on minimum burial age. Flood rings containing anomalously small earlywood vessels in pedunculate oak are formed in response to spring flooding within a narrow time window related to cambial phenology. They can be induced if a flooding event has occurred for at least two weeks during spring. The extreme reduction in vessel size is a consequence of a delay in vessel formation due to anoxic conditions related to flooding. Flood rings however, provide only limited information on the duration of flooding, as the flooding may have lasted for months (during winter) before it is recorded. It is concluded that the origin of wood-anatomical markers largely determines the temporal resolution. Markers induced by wounding or flooding show a high intra-annual temporal resolution and immediate effect on tree functioning, whereas burial might not be recorded three years after the triggering events. The different wood-anatomical markers addressed in this thesis illustrate the relevance of studying the mechanism behind the formation of markers for correct interpretation of the specific triggering factor as well as their temporal resolution. Only with this knowledge it becomes possible to reliably use wood-anatomical markers as archives to understand and reconstruct dynamics in geomorphic, entomologic, pathogenic or climatic factors. more...

Tropical forests cover only 7% of the earth’s land surface, but harbour almost half of the world’s biodiversity. These forests also provide many ecosystem services, such as the storage of carbon and the regulation of local and regional climate, and many goods such as timber and fruits. Furthermore, tropical forests contribute disproportionately to the global carbon cycle, storing an estimated 25% of the carbon stocks on land and accounting for a third of the terrestrial net primary productivity. Therefore, changes in forest cover or in the net uptake or loss of carbon by forests directly influences the global carbon cycle. Tropical forests are under increasing anthropogenic pressure and are undergoing rapid changes due to deforestation, conversion to other land uses and logging. Additionally, there is evidence that pristine and intact tropical forests are undergoing changes due to the effects of climate change. Concerted increases in biomass and tree growth have been found in studies monitoring intact tropical forests, suggesting that they acted as considerable carbon sinks over the past decades. On the other hand, decreasing or fluctuating forest growth and biomass have also been noted. These different changes have been attributed to different climatic drivers: growth increases have been suggested to arise from growth stimulation by increasing atmospheric CO2 concentrations, while growth decreases have been interpreted to reflect the limiting effects of increased temperature on growth. As monitoring plots usually cover only a few decades, it is still unclear whether these changes are pervasive or whether they simply reflect the effect of short-term climatic fluctuations on tree growth. Assessing whether changes have occurred over centennial scales is thus crucial to understanding whether and how tropical forests are reacting to climatic changes. In this thesis we apply tree-ring analysis on a pantropical study to assess longterm changes in growth of tropical forest trees. Tree-ring analysis was used to measure long-term growth rates of ~1350 trees of different species coming from three sites across the tropics. Trends in growth over the last two centuries were then analysed using an established an a new trend-detection method. Additionally, we applied the long-term growth data from rings to improve the evaluation of forest management practices in Cameroon. All samples were collected and measured within the TROFOCLIM project led by Pieter Zuidema. The project also includes two other PhD theses and sample collection was divided among the three PhD projects and the three sites: in Bolivia (samples collected by Peter van der Sleen), Cameroon (by me) and in Thailand (by Mart Vlam). The main objectives of this thesis were: (1) to assess the potential for using treerings in a wet tropical forest in Central Africa; (2) to project timber yields in the next logging round for four Cameroonian tree species; (3) to evaluate the sensitivity and accuracy of four commonly used methods to detect long-term trends in tree-ring data; and (4) to detect whether growth rates of tropical forest trees have changed over the past ~150 years. In Chapter 2 of this dissertation, we evaluated whether growth rings are formed annually in the wood of tree species growing under very high levels of precipitation (>4000 mm) in an African tropical forest. For this purpose, we assessed whether ring structures are formed in the wood of the 22 commercially exploited tree species and found that ring structures are indeed formed by more than half of these species (in 14 species), though with varying ring clarity. On four species we proved the annual character of ring formation using radiocarbon bomb-peak dating. That rings are formed under such high levels of precipitation is surprising, as these conditions are considered improper to induce ring formation. These results suggest that the potential of tree-rings analysis is more or less similar across the tropics. Based on our results and that of other studies, we estimate that tree rings can be used to measure tree growth and ages for around a quarter to a third of tropical tree species. Worldwide, over 400 million hectares of tropical forests are set aside for timber production. Attaining sustainable use of these forests is very important, in the light of the important role of tropical forests in retaining biodiversity and storing carbon. Ensuring that timber species are not overexploited is key to ensure that forest use is sustainable and entails finding a balance between economic gains and the (ecological) sustainability of logging operations. In Chapter 3, we integrated growth data from tree-rings with logging inventory data to forecast whether timber yields can be sustained in the next harvest round for four timber species in Cameroon. Under current logging practices, future logging yields were predicted to reduce moderately to strongly for all species. These yield reductions are worrisome for forest conservation, as loss of economic value may lead to conversion of forests to other land uses. We recommend that such calculations are needed for more species and argue that these simulations should include the effects of logging and eventual silvicultural measures on the growth and survival of trees. Lifetime tree growth data – as acquired by tree-ring analysis – contains longterm trends in growth that reflect the ontogenetic development of an individual or species, i.e., these data contains an age/size signal in growth. In Chapter 4 we evaluate the sensitivity, accuracy and reliability to detect long-term trends in growth of four methods that are commonly used to disentangle these age/size trends from long-term growth trends. We applied these growth-trend detection methods to measured growth data from tree rings and to simulated growth trajectories on which increasing an decreasing trends were imposed. The results revealed that the choice of method influences results of growth-trend studies. We recommend applying two methods simultaneously when analysing long-term trends – the Regional Curve Standardization and Size Class Isolation – as these methods are complementary and showed the highest reliability to detecting long-term growth changes. In Chapter 5, we analysed long-term growth trends in tropical forest trees using a pantropical approach applying the two recommended growth-trend detection methods. We showed that growth rates for most of the 13 tropical tree species, from the three sites across the tropics, decreased over the last centuries. These species-level changes may have important demographic consequences and may eventually lead to shifts in the species composition of tropical forests. We found no strong growth changes when analysing trends aggregated per site or across sites: only weak growth reductions were detected for the Thai site and across sites. These findings contrast growth increases that would be expected if tree growth is stimulated by increased ambient CO2. These growth reductions suggest worsening growth conditions for several tropical tree species, and could result from the negative effect of temperature increases on tree growth, or reflect the effect of large-scale disturbances on these forests. If one image becomes clear from this thesis it is that long-term data are crucial to enhance the management of tropical forests and to quantify changes happening in these forests. Tree-ring analysis provides this long-term perspective for tree growth and is thus a great tool to evaluate changes in the growth of trees, including for tropical species. One of the most important finding of this thesis is that many tropical species show long-term decreases in growth. These results suggest that the commonly assumed growth increases tropical forests, based on measurements over the last couple of decades, may be incorrect. This discrepancy in results could have strong consequences, among others leading to erroneous predictions of the carbon dynamics of tropical forests under future climate change. Combining monitoring plot data (to analyse short-term changes in growth and species composition) with remotely sensed data (to accurately determine forest land cover) and with the long-term growth data from tree rings is probably the best way forward to relate recent findings of short-term changes in tree growth and forest biomass to changes over the past centuries. Such integrative approaches are needed to better quantify and understand the effects of climate change on tropical forests. more...

Tropical forests cover only 7% of the earth’s land surface, but harbour almost half of the world’s biodiversity. These forests also provide many ecosystem services, such as the storage of carbon and the regulation of local and regional climate, and many goods such as timber and fruits. Furthermore, tropical forests contribute disproportionately to the global carbon cycle, storing an estimated 25% of the carbon stocks on land and accounting for a third of the terrestrial net primary productivity. Therefore, changes in forest cover or in the net uptake or loss of carbon by forests directly influences the global carbon cycle. Tropical forests are under increasing anthropogenic pressure and are undergoing rapid changes due to deforestation, conversion to other land uses and logging. Additionally, there is evidence that pristine and intact tropical forests are undergoing changes due to the effects of climate change. Concerted increases in biomass and tree growth have been found in studies monitoring intact tropical forests, suggesting that they acted as considerable carbon sinks over the past decades. On the other hand, decreasing or fluctuating forest growth and biomass have also been noted. These different changes have been attributed to different climatic drivers: growth increases have been suggested to arise from growth stimulation by increasing atmospheric CO2 concentrations, while growth decreases have been interpreted to reflect the limiting effects of increased temperature on growth. As monitoring plots usually cover only a few decades, it is still unclear whether these changes are pervasive or whether they simply reflect the effect of short-term climatic fluctuations on tree growth. Assessing whether changes have occurred over centennial scales is thus crucial to understanding whether and how tropical forests are reacting to climatic changes. In this thesis we apply tree-ring analysis on a pantropical study to assess longterm changes in growth of tropical forest trees. Tree-ring analysis was used to measure long-term growth rates of ~1350 trees of different species coming from three sites across the tropics. Trends in growth over the last two centuries were then analysed using an established an a new trend-detection method. Additionally, we applied the long-term growth data from rings to improve the evaluation of forest management practices in Cameroon. All samples were collected and measured within the TROFOCLIM project led by Pieter Zuidema. The project also includes two other PhD theses and sample collection was divided among the three PhD projects and the three sites: in Bolivia (samples collected by Peter van der Sleen), Cameroon (by me) and in Thailand (by Mart Vlam). The main objectives of this thesis were: (1) to assess the potential for using treerings in a wet tropical forest in Central Africa; (2) to project timber yields in the next logging round for four Cameroonian tree species; (3) to evaluate the sensitivity and accuracy of four commonly used methods to detect long-term trends in tree-ring data; and (4) to detect whether growth rates of tropical forest trees have changed over the past ~150 years. In Chapter 2 of this dissertation, we evaluated whether growth rings are formed annually in the wood of tree species growing under very high levels of precipitation (>4000 mm) in an African tropical forest. For this purpose, we assessed whether ring structures are formed in the wood of the 22 commercially exploited tree species and found that ring structures are indeed formed by more than half of these species (in 14 species), though with varying ring clarity. On four species we proved the annual character of ring formation using radiocarbon bomb-peak dating. That rings are formed under such high levels of precipitation is surprising, as these conditions are considered improper to induce ring formation. These results suggest that the potential of tree-rings analysis is more or less similar across the tropics. Based on our results and that of other studies, we estimate that tree rings can be used to measure tree growth and ages for around a quarter to a third of tropical tree species. Worldwide, over 400 million hectares of tropical forests are set aside for timber production. Attaining sustainable use of these forests is very important, in the light of the important role of tropical forests in retaining biodiversity and storing carbon. Ensuring that timber species are not overexploited is key to ensure that forest use is sustainable and entails finding a balance between economic gains and the (ecological) sustainability of logging operations. In Chapter 3, we integrated growth data from tree-rings with logging inventory data to forecast whether timber yields can be sustained in the next harvest round for four timber species in Cameroon. Under current logging practices, future logging yields were predicted to reduce moderately to strongly for all species. These yield reductions are worrisome for forest conservation, as loss of economic value may lead to conversion of forests to other land uses. We recommend that such calculations are needed for more species and argue that these simulations should include the effects of logging and eventual silvicultural measures on the growth and survival of trees. Lifetime tree growth data – as acquired by tree-ring analysis – contains longterm trends in growth that reflect the ontogenetic development of an individual or species, i.e., these data contains an age/size signal in growth. In Chapter 4 we evaluate the sensitivity, accuracy and reliability to detect long-term trends in growth of four methods that are commonly used to disentangle these age/size trends from long-term growth trends. We applied these growth-trend detection methods to measured growth data from tree rings and to simulated growth trajectories on which increasing an decreasing trends were imposed. The results revealed that the choice of method influences results of growth-trend studies. We recommend applying two methods simultaneously when analysing long-term trends – the Regional Curve Standardization and Size Class Isolation – as these methods are complementary and showed the highest reliability to detecting long-term growth changes. In Chapter 5, we analysed long-term growth trends in tropical forest trees using a pantropical approach applying the two recommended growth-trend detection methods. We showed that growth rates for most of the 13 tropical tree species, from the three sites across the tropics, decreased over the last centuries. These species-level changes may have important demographic consequences and may eventually lead to shifts in the species composition of tropical forests. We found no strong growth changes when analysing trends aggregated per site or across sites: only weak growth reductions were detected for the Thai site and across sites. These findings contrast growth increases that would be expected if tree growth is stimulated by increased ambient CO2. These growth reductions suggest worsening growth conditions for several tropical tree species, and could result from the negative effect of temperature increases on tree growth, or reflect the effect of large-scale disturbances on these forests. If one image becomes clear from this thesis it is that long-term data are crucial to enhance the management of tropical forests and to quantify changes happening in these forests. Tree-ring analysis provides this long-term perspective for tree growth and is thus a great tool to evaluate changes in the growth of trees, including for tropical species. One of the most important finding of this thesis is that many tropical species show long-term decreases in growth. These results suggest that the commonly assumed growth increases tropical forests, based on measurements over the last couple of decades, may be incorrect. This discrepancy in results could have strong consequences, among others leading to erroneous predictions of the carbon dynamics of tropical forests under future climate change. Combining monitoring plot data (to analyse short-term changes in growth and species composition) with remotely sensed data (to accurately determine forest land cover) and with the long-term growth data from tree rings is probably the best way forward to relate recent findings of short-term changes in tree growth and forest biomass to changes over the past centuries. Such integrative approaches are needed to better quantify and understand the effects of climate change on tropical forests. more...

This study has aims to determine the age and to estimate the growth parameters using scales of the species. Individuals of Piaractus mesopotamicus (Holmberg, 1887) used in this study were captured in the commercial fishery conducted in the region, along the year 2006. The model selected to express the growth of the species was the von Bertalanffy Sl= Sl∞*[1-exp-k(t-to)]. To determine if scales are suitable for studying the growth of pacu, we analyzed the relation between standard length (Sl) and the radius of the scales through linear regression. The period of annuli formation was determined analyzing the variations in the marginal increment and evaluating the consistency of the readings through the analysis of the coefficient of variations (CVs) for the average standard lengths of each age (number of rings) observed in the scales. The relationship between Ls of the fish and the radius of the scales showed that scales can be used to study the age and growth of P. mesopotamicus (R= 0.79). CVs were always below 20%, demonstrating the consistency of the readings. Annuli formation occurred in February, probably related to trophic migration that occurs in this month in the region. Equations that represents the growth in length obtained for P. mesopotamicus are Sl=50.00*[1-exp-0.18(t-(-3.00)] for males and Sl=59.23*[1-exp-0.14(t-(-3.36)] for females. The growth parameters obtained in this study were lower compared to other studies previously conducted for the same species and can related to overexploitation that species is submitted by fishing in the region. These values show also that females of pacu attain greater asymptotic length than males that growth faster. Este estudo tem como objetivo determinar a idade e estimar os parâmetros de crescimento usando as escamas da espécie. Esta informação pode ser usada em outros estudos sobre dinâmica de estoques da espécie na área estudada. Os indivíduos do Piaractus mesopotamicus (Holmberg, 1887) usados nesse estudo foram capturados na pesca comercial, desenvolvida na região durante o ano de 2006. O modelo escolhido para analisar o crescimento da espécie foi o de Von Bertalanffy (Cp= Cp∞*[1-exp-k(t-to)]. Para saber se as escamas são apropriadas para estudos de crescimento do pacu, nós analisamos a relação entre o comprimento padrão (Cp) e o raio das através de regressão linear. O período de formação dos anéis foi determinado analisando as variações no incremento marginal e a consistência das leituras foi avaliada através da análise do coeficiente de variação (CVs) do comprimento padrão médio para cada idade (número de anéis) observado nas escamas. A correlação entre o Ls do peixe e o raio das escamas mostrou que as escamas podem ser utilizadas para estudos de crescimento do P. mesopotamicus (R= 0.79). Os CVs foram sempre abaixo de 20% demonstrando consistência nas leituras. A formação dos anéis ocorreu em fevereiro provavelmente relacionada com a migração trófica que ocorre neste mês na região. As equações que representa o crescimento em comprimento obtidas para o P. mesopotamicus são: Cp=50.00*[1-exp-0.18(t-(-3.00)] para machos e Cp=59.23*[1-exp-0.14(t-(-3.36)] para fêmeas. Os parâmetros de crescimento encontrados neste estudo foram mais baixos quando comparados com outros estudos para a mesma espécie realizados anteriormente e pode estar relacionado com "overexplotation" pela pesca que a espécie é submetida na área. Esses valores mostram ainda que as fêmeas do pacu atingem comprimentos assintóticos maiores que os machos que crescem mais rápido. more...

Background The content of medicinal bioactive constituents in huangqi is affected by plant age. In this study, we devised a quick and convenient method for determining the age of huangqi, which was cultivated in Hunyuan County (Shanxi Province). Methods 1, 2, 3, 4, 5, 8, 10 growth years huangqi had 38 samples, all samples were collected separately. The growth rings in these samples were observed after making paraffin section and freehand-section. The relationship between growth rings and its growth years was analyzed by SPSS 19.0 software. Histochemical localization of total flavones and saponins in huangqi was determined by color reactions. The concentration of four flavonoids and two saponins in the roots of huangqi of different ages and different organizational structure (normal roots and rotten heart roots) were determined by HPLC-DAD and HPLC-ELSD. The results were analyzed by SPSS 19.0 software. Results All huangqi samples had clear growth rings, and the statistical result about growth rings (X) and growth years (Y) showed significant correlation (r = 1, P = 0.000). The calibration curves of these six ingredients showed good linearity respectively, with significant correlation. All relative standard deviations (RSDs) of precision, recovery, repeatability, and stability experiments were less than 2%. Roots of 5-year-old plants contained the highest concentrations of total flavonoids and saponins. Saponin concentrations increased toward the center of the roots, whereas the four flavonoids showed an opposite trend in tissue distribution. Conclusion The growth year of huangqi (Hunyuan County, Shanxi Province) could be determined soon and conveniently by naked eyes after staining phloroglucinol-HCl solution on freehand section. The content of saponins and flavonoids in rotten heart root and the surrounding normal tissues were affected by the formation and the extent of rotten heart. Electronic supplementary material The online version of this article (doi:10.1186/s13020-017-0135-z) contains supplementary material, which is available to authorized users. more...

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