ABSTRACT
Resumen Introducción: Los estudios dendrocronológicos en México se han basado principalmente en las coníferas, mientras que las especies de madera dura han sido poco estudiadas. Este ha sido el caso del género Quercus, con una alta diversidad taxonómica en el país pero que no ha sido estudiado con fines dendrocronológicos, a pesar de los valores ecológicos y económicos de sus especies. Objetivo: En la presente investigación se determinó el potencial dendroclimático de Quercus sideroxyla en el noroeste de México, y su relación con variables climáticas como precipitación y temperatura. Métodos: La investigación se desarrolló en el estado de Durango en el ejido Chavarría Viejo en las coordenadas (23º43' N & 105º33' W), se recolectaron muestras de 5 a 7 cm en dos sitios bajo aprovechamiento forestal y se procesaron mediante técnicas dendrocronológicas convencionales. Resultados: Se desarrolló una cronología de ancho de anillo total, la cual se compuso por 30 muestras de 16 árboles para el período de 1917 a 2018 (101 años). Se obtuvieron valores de intercorrelación entre series de 0.43, de sensibilidad media de 0.36, relación señal-ruido de 3.53 y autocorrelación de primer orden (0.58). En cuanto a la relación clima-crecimiento, los valores de índice de ancho de anillo se correlacionaron con datos de la estación climática más cercana al sitio de estudio; donde la precipitación invierno-primavera (enero-mayo) fue la variable de mayor influencia en el crecimiento de la especie. Conclusiones: Con base en los parámetros dendrocronológicos se demuestra el alto potencial de la especie para ser empleada en estudios dendroclimáticos en la región, la respuesta de la especie a la precipitación es similar al de las coníferas con las que cohabita.
Abstract Introduction: Dendrochronological studies in Mexico have been mainly based on conifers, while hardwood species have been little studied. This has been the case of the genus Quercus, which has a high taxonomic diversity in the country but has not been previously studied for dendrochronological issues, despite the ecological and economic values of oak species. Objective: In the present investigation, the dendroclimatic potential of Quercus sideroxyla in Northwestern Mexico was determined, as well as its relationship with climatic variables such as precipitation and temperature. Methods: The research was carried out in the state of Durango, Chavarría Viejo with coordinates (23º43' N & -105º33' W). Samples of 5 cm to 7cm were collected in two sites under forest exploitation and processed by conventional dendrochronological techniques. Results: A chronology of total ring width was developed, which was composed of 30 samples from 16 trees for the period from 1917 to 2018 (101 years). Inter-series intercorrelation values of 0.43, mean sensitivity of 0.36, signal-to-noise ratio of 3.53 and first-order autocorrelation (0.58) were obtained. Regarding the climate-growth relationship, the ring width index values were correlated with data from the climatic station nearest to the study site, where winter-spring precipitation (January-May) was the variable with the greatest influence on the growth of the species. Conclusions: Based on the dendrochronological parameters, the high potential of the species that were used in dendroclimatic studies in the region has demonstrated that the response of the species to precipitation is similar to that of the conifers with which the Quercus sideroxyla shares its habitat with.
Subject(s)
Chronology , Quercus/growth & development , ClimateABSTRACT
The quality of Astragali Radix (AR) was closely related to the growth period. However, the current commodity grades of AR were only divided by diameter but not directly related to the growth period, which leads to the contradiction between the grade standard and the quality evaluation index. Therefore, solving this problem will be the key for the quality evaluation of AR. The present study established a potential quality evaluation approach for the absolute growth years' wild Astragali Radix (WAR) and transplanted Astragali Radix (TAR) based on the chemical components and anti-heart failure efficacy through adopting a bare-handed sections approach to rapidly identify the growth years of WAR. In this study, the absolute growth years of WAR were obtained by identifying the growth rings of 1-6 growth years root through the methods. The contents of flavonoids and saponins in 2-6 growth years' WAR were determined by HPLC-UV-ELSD. The contents of 12 chemical components and the anti-fatigue failure effects of WAR (4-year-old) and TAR were compared on rat models of heart failure induced by doxorubicin. Meanwhile, NMR-based untargeted metabolomics studies were performed to investigate the regulative effects of WAR and TAR. The result shows that the numbers of growth rings were consistent with the actual growth periods of AR. The HPLC-UV-ELSD determination indicated that the content of total flavonoids in WAR was significantly higher than that in TAR. Pharmacodynamics analysis revealed that the effects of WAR on cardiac function parameters (EF, FS and LVIDs), contents of serum CK and BNP were superior to those of TAR. 13 metabolites of heart were identified that had a higher rate of change in WAR group than TAR. Overall, a rapid identification method for the growth years of WAR was established, and the fact that WAR were significantly better than TAR in the heart failure rats was first proved in the paper. This study provided a scientific basis for establishing a novel commodity specification and grade of AR for clinical rational drug use.
ABSTRACT
Resumen Los estudios dendrocronológicos se utilizan para reconstruir algunas variables climáticas; en México, estos estudios se han centrado en los bosques templados del centro y del norte, donde los árboles presentan anillos anuales bien definidos. Pocos estudios se han llevado a cabo en la parte sur del país, donde el crecimiento anual del anillo no se identifica fácilmente y, por lo tanto, esto hace que la datación se dificulte. Se analizó el potencial dendrocronológico de Pinus oocarpa para la reconstrucción de variables climáticas en la porción noroeste de Lagunas de Montebello, Chiapas. Empleando un muestreo selectivo se recolectaron 65 núcleos de incremento de 34 árboles. Aunque las muestras presentaron una alta frecuencia de anillos falsos (8 a 60 %), se logró fechar 30 muestras de 22 árboles (46 %) mediante técnicas dendrocronológicas estándar y el desarrollo de cronologías de anillo total, madera temprana y madera tardía para un período de 91 años (1925-2015). Se encontró una influencia significativa de la precipitación media y de la temperatura media máxima y mínima del período 1961-2004 sobre el crecimiento anual de P. oocarpa. Los resultados muestran que la precipitación inviernoprimavera (enero-mayo) fue la más importante para el crecimiento del anillo anual de la especie. Sin embargo, la correlación más alta se observó entre la precipitación de primavera (marzo-mayo) y la cronología de la madera temprana (r = 0.719, P < 0.05). La cronología de la madera temprana también mostró potencial para reconstruir la temperatura mínima (marzo a mayo) (r = 0.732, P < 0.05), mientras que la cronología de madera tardía registra potencial para reconstruir la temperatura máxima (septiembreenero) (r = 0.714, P < 0.05). Estos resultados muestran que P. oocarpa puede emplearse para reconstruir variables climáticas en los trópicos mexicanos. Se recomienda explorar nuevas áreas con árboles más viejos a fin de aumentar la extensión de las cronologías y reconstruir los registros climáticos varios siglos en el pasado.(AU)
Abstract Dendrochronological studies are used to reconstruct some climatic variables; in México these studies have focused on central and Northern temperate forests where trees present well defined annual rings. Few studies have been carried out in the Southern part of the country where annual ring growth is not easily identified and thus makes cross-dating problematic. We analyzed the dendrochronological potential of Pinus oocarpa Schiede for reconstructing climatic variables in the Northwest portion of Lagunas de Montebello, Chiapas. We used a selective sampling approach and collected 65 increment cores from 34 trees. While our samples showed a high frequency of false rings (8 to 60 %), we were able to date 30 samples from 22 trees (46 %) using standard dendrochronological techniques and developed total chronologies for total ring width, earlywood, and latewood for a period of 91 years (1925-2015). We found a significant influence of mean precipitation and mean maximum and minimum temperature over the annual ring growth of P. oocarpa in the period 1961-2004. Our results show that winter-spring precipitation (January-May) was the most important for the species' annual ring growth. However, we found the highest correlation between spring (March-May) precipitation and the earlywood chronology (r = 0.719, P < 0.05). The earlywood chronology also showed potential for reconstructing minimum temperatures (March to May) (r = 0.732, P < 0.05), while the latewood chronology had the potential for reconstructing the maximum temperature (September to January) (r = 0.714, P < 0.05). These results showed that P. oocarpa can be used to reconstruct climatic variables in the Mexican tropics. We recommend that new areas with older trees should be explored in order to increase the depth of chronologies and reconstruct climate records several centuries into the past.(AU)
Subject(s)
Wood , Climate Change , Pinus , Trees , MexicoABSTRACT
The purpose of this study was to combine morphological, microscopic, UHPLC multiple-component assay and fingerprinting studies in order to evaluate the quality of Moutan Cortex (MC) systematically. The root system of Paeonia suffruticosa was measured to compare the morphological variation and the chemical composition of different grades of MC was discussed according to previous studies. The difference between the main microscopic features of MC powder and the xylem powder is dramatic, the MC powder contains great amount of starch granules and clusters of calcium oxalate, while the xylem powder displays considerable vessels. Interestingly, the growth rings of P. suffruticosa was first reported in the xylem of the root transection, this can help to determine the growth years of the plant. Moreover, through the assay of 16 component, MC produced in Tongling and Bozhou in Anhui province were compared, content of PGG in MC produced in Bozhou was significantly higher than MC produced in Tongling (<0.01). MC with different growth years, MC with xylem and unprocessed MC and MC decoction pieces were compared respectively by combining the results of 16 compounds assay and fingerprinting. It is proposed that the quality evaluation standard include the assay of paeoniflorin. Above all, the holistic quality difference can be evaluated more comprehensively by combining multiple analytical methods.
ABSTRACT
The growth years of medicinal materials are closely related to their quality, and "Herb-chronology" has been used to determine the growth years of perennial dicotyledonous plants in recent years. On the basis of conventional paraffin section and freehand section, the anatomical study on roots of seven Sect. Paeonia species and main roots of cultivated Paeonia lactiflora was conducted in this paper. The results showed that, there existed some differences in microstructure of the seven species such as P. lactiflora, P. obovata, P. veitchii, P. mairei, P. anomala, P. sinjiangensis and P. anomala var. intermedia, and this could be used to distinguish different species. In the roots of seven Sect. Paeonia species, distinct growth rings were formed because that the different diameters or density of xylem vessels in the secondary xylem formed clusters and arranged interrupted rings in tangential direction. There were growth rings in the main roots of P. lactiflora cultivated 1-4 years in Siping, Jilin, which were all consistent with their growth years. Due to the similar growth characteristics between wild Sect. Paeonia species and cultivated P. lactiflora, the growth rings can provide a basis for the age identification and lay the foundation for the quality evaluation of Paeoniae Radix Rubra.
ABSTRACT
A madeira juvenil em maior proporção no fuste e suas características físicas, mecânicas, químicas e anatômicas diminuem a qualidade do material. Esse estudo teve como objetivo estimar a idade de segregação do lenho juvenil e adulto pelo comprimento dos traqueoides em Pinus elliottii Engel, aos 30 anos de idade. Para tanto, seis árvores foram selecionadas, com base no diâmetro dominante, em um povoamento localizado no Colégio Agrícola de Frederico Westphalen/UFSM. Após o abate, no disco correspondente a 0,15 metros de altura, foram marcadas e seccionadas baguetas centrais de onde se retirou o lenho inicial dos trinta anéis de crescimento, no sentido medula-casca, para maceração. A segregação dos dois tipos de lenhos foi determinada pela variação radial da característica anatômica em estudo através de duas regressões lineares simples. Os resultados indicaram que o comprimento dos traqueoides apresentou padrão de variação crescente no sentido medula-casca, indicando assim que os menores valores foram observados próximos à medula e correspondem aos primeiros anéis de crescimento. A idade de segregação do lenho de Pinus elliottii definida por meio do comprimento de traqueoides foi de, aproximadamente, dez anos.
The juvenile wood in greater proportion in the stem and its physical, mechanical, chemical and anatomical characteristics decrease the quality of the material. This study was undertaken to estimate the segregation age of juvenile and mature wood by tracheid length of Pinus elliottii Engel, at 30 years of age. Six trees were selected, on the basis of the dominant diameter, in a stand located in Agricultural College of Frederico Westphalen/UFSM. After cutting down, in the disk corresponding to the 0.15 meters, were marked and sectioned centrals baguettes from where was removed the initial wood of the thirty growth rings, in pith-to-bark direction, for maceration. The segregation of the two types of wood was defined by radial variation of the anatomical characteristic in study through two simple linear regressions. The results indicated that the tracheid length showed a pattern of increasing from pith to bark, indicating that the lowest values were observed near the pith and correspond to the first growth rings. The age of segregation of the Pinus elliottii wood defined by tracheid length was, approximately, ten years-old.
ABSTRACT
The knowledge about the existence of annual tree rings in tropical trees, which was already found at the beginning of the last century, was ignored by many scientists for a long time. Wood samples of 80 tree species from seven different sites belonging to Satipo and Chanchamayo provinces in Central Forest, Perú. Wood slices were taken at 1.30m height, following the Peruvian Technical Norms (NTP) 251-008, COPANT norms 30:1-019 and IAWA (1989). Results showed that 24 of the 80 tree species analyzed showed a potential for dendrocronological studies, 25 had problems for growth-rings analysis, and 31 did not have potential. The problems most frequently found were: barely visible or irregular ring growth, parenchyma bands and multiseriate rays difficult to be identified in rings growth. The “T” Student test showed that the significant variation in vessel and fiber diameters between growth zones (Early-wood and late-wood) of species with potential for dendrocronology, do have a periodic cells production, so is possible to suggest the annual formation of each growth-ring. However, those species without potential to dendrocronology may be influenced by of a lot of factors, such as biotic and abiotic conditions of environment, as well as the genetic aspect of each species.
El conocimiento acerca de la existencia de anillos anuales en árboles tropicales, se conoce desde principios del siglo pasado, pero fue ignorado por muchos científicos durante largo tiempo. La investigación fue realizada en el Laboratorio de Tecnología de la Madera e Industrias Forestales de la Universidad Nacional del Centro del Perú, con la finalidad de caracterizar anatómicamente los anillos de crecimiento de 80 especies arbóreas potenciales para estudios dendrocronológicos; provenientes de las provincias de Satipo y Chanchamayo en la Selva Central del Perú. Para el estudio se consideraron las normas COPANT 30:1-019, Normas Técnicas Peruanas (NTP) 251-008 y la Lista Estándar de la IAWA 1989. Entre los resultados más sobresalientes tenemos: el 30% de las ochenta especies estudiadas tienen buen potencial para estudios dendrocronológicos. La mayoría de estas especies, están delimitadas por una banda de fibras acortadas radialmente. Entre los problemas encontrados, se puede destacar la presencia de anillos con dificultad para ser visualizados, la presencia de anillos irregulares y la presencia de parénquima en bandas. Las características microscópicas, muestran que la variación significativa en dimensiones de fibras y vasos entre zonas de crecimiento (madera temprana y madera tardía), de las especies potenciales para dendrocronología, tienen una producción de células en forma periódica, lo que podría sugerir la formación anual de cada anillo.
Subject(s)
Trees/anatomy & histology , Wood/anatomy & histology , Peru , Tropical Climate , Trees/classification , Wood/classificationABSTRACT
Teak (Tectona grandis) is one of the most valuable timbers in international trade and an important species for tropical forestry. Teak is found on the island of East Timor but no information is available on teak growth from this region. A pure stand planted in 1940-50 in the North of East Timor and left unmanaged was studied. Fifteen trees were sampled in October-November 2003 and stem discs taken at three height levels of its height (1.7m, 9.5m and 18.7m), and cores were collected at DBH. Transverse surfaces of the discs and cores were polished for ring identification. Core cross sections were first digitized and disc cross sections were observed under the microscope. Three randomly selected radii were analyzed in each disc. Ring width measurement and ring counting were done using image analysis software. The distinction between heartwood and sapwood was performed macroscopically by colour difference, and heartwood radius and sapwood width were measured. The relationship between stem and heartwood radius was studied for each disc and heartwood percentage by radius was determined. Radial ring width curves are presented for the different axial positions within the stem, and ring width variability was analyzed. Growth rates were calculated and age-radius relationships were estimated using cumulative growth curves. Growth rings were large and well defined in the juvenile phase, reflecting the specie’s fast-growing character. The year-to-year variation of ring width showed a similar pattern among trees. Mean ring width ranged between 4.3-7.3mm for the first 20 years and 3.3-5.1mm for 30 to 45 years. Pith eccentricity was evident in the lower part of the stem and ring wedging occurred. On average, heartwood represented 84% of the radius and sapwood contained 6 to 11 rings. The age-related variation of ring width and the occurrence in the lower part of the tree stems of eccentricity and wedging rings, highlights the importance of appropriate stand management, particularly regarding basal density distribution over time, whenever optimized timber production is envisaged.
La madera de teca (Tectona grandis L.f.) es una de las más valiosas en el comercio internacional y una especie importante para la silvicultura tropical. La teca se encuentra en la isla de Timor Leste, pero no existe información disponible sobre su crecimiento en esta región. Se estudió una plantación pura no manejada que fue establecida entre 1940 y 1950 en el Norte de Timor Leste. Entre Octubre- Noviembre 2003 se cosecharon 15 árboles y al tronco se les extrajeron discos a tres niveles de altura (1.7m, 9.5m y 18.7 m), y se recolectaron núcleos a la altura del pecho (DAP). El conteo y la medición de los anillos se realizaron mediante el software de análisis de imagen. La distinción entre el duramen y la albura se realizó macroscópicamente por la diferencia de color, y se midieron el radio del duramen y el ancho de la albura. Para cada disco se estudió la relación entre el tallo y radio del duramen y el porcentaje del duramen. Las curvas de variación del ancho de los anillos se presentan para las diferentes posiciones axiales dentro del tronco y se analizó la variabilidad del ancho de los anillos. Las tasas de crecimiento fueron calculadas y las relaciones de radio con la edad se calcularon usando las curvas de crecimiento acumulado. Los anillos de crecimiento eran grandes y bien definidos en la fase juvenil, lo que refleja el carácter de crecimiento rápido de esta especie. La variación en la anchura de los anillos año a año mostró un patrón similar entre los árboles. La anchura media del anillo osciló entre 4.3-7.3mm para los primeros 20 años y 3.3-5.1mm para los de 30 a 45 años. La excentricidad de la médula fue evidente en la parte inferior del tallo y se observó la formación de anillos sobrepuestos. En promedio, el duramen representó el 84% del radio y la albura mostró entre 6 y 11 anillos. La variación del ancho de los anillos con la edad, la presencia de excentricidad en la parte inferior del árbol y los anillos sobrepuestos pone de relieve la importancia del manejo forestal con particular atención a la distribución de densidad basal en el tiempo, cuando se pretende la producción optimizada de la madera.
Subject(s)
Trees , Verbenaceae/growth & development , Timor-Leste , Verbenaceae/classificationABSTRACT
Age and growth of the hybrid tilapia Oreochromis niloticus x Oreochromis aureus (Perciformes: Cichlidae) in the dam “Zimapan” Mexico. Studies on age and growth in fishes are essential to establish models on population dynamics. The previos issues were determined in this study by scale growth analyses. Between September 2003 and May 2004, 382 organisms were captured using gill and atarraya nets. Eight samples were developed every month a long this study. Standard length in centimeters (Le), total weight in grams (Pt), scale length in centimeters (Lesc) and growth rings were determined. The size and weight ranged from 38 to 232mm (Le) and 8.7 to 311.9g (Pt), respectively. The growth rings analyses reveal four age groups, being the sec-ond group the most representative with 34.3% of the total sampled. The scale ring analyses showed two growth rings, one develops between November-January and the other between April-May, in good correlation with low temperature and gonad development, respectively. The growth parameters were established as: L∞=281.1mm, W∞=877.1g, K=0.33 and T0=0.88year -1. The growth curves based on length and weight were described by using the von Bertalanffy model: Le =28.11[1-e-0.33(t+0.88)] and Pt =877.17[1-e-0.33(t+0.88)]³. Finally, it is concluded that commercial catches in this dam are between a year and year and half-old when exploited. Rev. Biol. Trop. 59 (2): 761-770. Epub 2011 June 01.
La edad y crecimiento de la tilapia Oreochromis niloticus x Oreochromis aureus fueron determinados por medio de la lectura de escamas. Un total de 382 individuos fueron capturados mediante el uso de redes agalleras y atarrayas. Ocho recolectas mensuales se llevaron a cabo entre septiembre 2003-mayo 2004; se registraron los datos de longitud estándar en cm. (Le), el peso total en g (Pt) y se obtuvieron muestras de escamas para registrar el largo de la escama en mm. (Lesc) y el número de anillos de crecimiento formados. Las tallas y pesos de recolecta variaron entre 38 a 232mm (Le) y de 8.7 a 311.9g de peso total (Pt) respectivamente. El recuento de los anillos anuales en escamas, permitió establecer cuatro grupos de edad, siendo el grupo de edad 2 el más representativo, con un 34.3% de la población muestreada. El cálculo de los incrementos marginales del crecimiento mensual de las escamas, sugirió la formación de dos anillos, uno de ellos se forma en los meses de noviembre-enero y otro en los meses de abril-mayo, los cuales coinciden con la época de bajas temperaturas y de madurez gonádica respectivamente. Los parámetros de crecimiento quedaron establecidos en: L∞=281.1mm, W∞=877.1g, K=0.33 y T0=0.88/año. Las curvas de crecimiento en longitud y peso se describieron mediante las ecuaciones de von Bertalanffy: Le=28.11 [1- e-0.33(t+0.88)] y Pt=877.17 [1-e-0.33(t+0.88)]³. Finalmente, se concluyó que los peces que se explotan en la represa mediante captura comercial presentan entre un año y año y medio de edad.