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1.
Sci Total Environ ; 916: 170252, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38253093

RESUMO

Global climate change is having significant effects on plant growth patterns and mountain plants can be particularly vulnerable to accelerated warming. Rising temperatures are releasing plants from cold limitation, such as at high elevations and latitudes, but can also induce drought limitation, as documented for trees from lower elevations and latitudes. Here we test these predictions using a unique natural experiment with Himalayan alpine shrub Rhododendron anthopogon and its growth responses to changing climate over a large portion of its latitudinal and elevational ranges, including steep precipitation and temperature gradients. We determined growth dynamics during the last three decades, representing period of accelerated warming, using annual radial growth increments for nine populations growing on both wet and warm southern localities and drier and cold northern localities in the Himalayas along elevation gradients encompassing the lower and upper species range limits. A significant growth increase over past decades was observed after controlling for confounding effect of shrub age and microsites. However, the magnitude of increase varied among populations. Particularly, populations situated in the lower elevation of the northernmost (cold and dry) locality exhibited most substantial growth enhancement. The relationship between growth variability and climate varied among populations, with the populations from the coldest location displaying the strongest responsiveness to increasing minimum temperatures during July. Minimum temperatures of April and August were the most important factor limiting the growth across most populations. Potential warming-induced drought limitation had no significant impact on growth variation in any part of the species geographic range. Overall, our findings indicate that plant growth is continuously increasing in recent decades and growth-climate relationships are not consistent across populations, with populations from the coldest and wettest localities showing stronger responses. The observed patterns suggest that dwarf-shrubs benefit from ongoing warming, leading to increased shrubification of high elevation alpine ecosystems.


Assuntos
Ecossistema , Aquecimento Global , Mudança Climática , Árvores , Temperatura , Plantas
2.
Sci Total Environ ; 918: 170539, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38296069

RESUMO

We lack understanding of how variable is radial growth of coexisting tree and shrub species, and how growth is constrained by drought depending on site aridity. Here, we compared the radial growth of two widespread and coexisting species, a winter deciduous shrub (Amelanchier ovalis Medik.) and an evergreen conifer tree (Pinus sylvestris L.). We sampled four sites in Northeastern Spain subjected to different aridity levels and used dendrochronological methods to quantify growth patterns and responses to climate variables. The growth of the two species varied between regions, being lower in the driest sites. The first-order autocorrelation (growth persistence) was higher in more mesic sites but without clear differences between species. Tree and shrub growth negatively responded to elevated summer temperatures and positively to spring-summer precipitation and wet conditions. However, negative growth responses of the shrub to drought were only observed in the two driest sites in contrast to widespread responses of the tree. Abrupt growth reductions were common in the drier sites, but resilience indices show that the two species rapidly recovered pre-drought growth levels. The lower growth synchrony of the shrub as compared to the tree can be due to the multistemmed architecture, fast growth and low stature of the shrub. Besides, the high dependency of the shrub growth on summer rainfall can explain why drought limitations were only apparent in the two driest sites. In any case, results point out to the dendrochronological potential of shrubs, which is particularly relevant giving its ability to inhabit woodlands and treeless regions under harsh climatic conditions. Nevertheless, further research is required to elucidate the capacity of shrub species to tolerate drought, as well as to understand how shrubs thrive in water- and cold-limited environments.


Assuntos
Pinus sylvestris , Pinus , Árvores , Secas , Florestas , Estações do Ano , Mudança Climática
3.
J Environ Manage ; 351: 119781, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38113792

RESUMO

The Amazonian clearwater igapós are poorly studied floodplain ecosystems that are mainly covered by forests and are undergoing massive threats due to changes in land use and climate. Their hydrochemical characteristics and edaphic conditions fall between those of the eutrophic várzea floodplains on whitewater rivers and those of the oligotrophic igapós on blackwater rivers. Previous studies have indicated the management potential of timber species in the highly dynamic várzea floodplains due to the fast tree growth and high forest productivity. Timber resource management, however, is not recommended for the blackwater ecosystem because of its slow dynamics and high vulnerability to disturbances. For clearwater igapós, information on the potential for sustainable management of timber resources is lacking. In this study, we modeled the growth in diameter, height, and volume to derive species-specific minimum logging diameters (MLD) and felling cycles (FC) for eight merchantable species in the clearwater igapós of the Branco and Tapajós rivers in the northern and southern Amazon Basin, respectively. Diameter growth was modeled by analyzing the tree rings that are annually formed in the Amazonian floodplains as a consequence of the regular and predicable long-term flooding. Growth modeling followed the guidelines of the Growth-Oriented Logging (GOL) concept, with the adjustment of diameter growth improved by applying nonlinear mixed-effects regression. MLDs varied from 36 to 90 cm and FCs ranged from 6 to 21 years, which diverges from the standards of Brazilian logging regulations (MLD: 50 cm; FC: 25-35 years). This indicates the potential for timber resource management, which should be tested and introduced at small scales, integrated in protected areas to stepwise promote the sustainable management of these natural resources by traditional communities to increase their income and the conservation of this ecosystem.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Florestas , Inundações , Especificidade da Espécie
4.
Materials (Basel) ; 16(24)2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38138724

RESUMO

Research on existing wooden structures relies on non-destructive and semi-destructive techniques. One of the methods enabling the estimation of the physico-mechanical characteristics of wood in building structures based on established correlational relationships is the sclerometric method. The challenge in utilizing these known correlational relationships is the lack of data regarding the impact of frequently occurring factors in objects on sclerometric test results. This paper presents the influence of selected factors on the results of sclerometric tests, such as temperature, the direction of testing in relation to annual growth rings, and the physical orientation of the measuring device. The research was conducted on pine, spruce, and fir elements, each subjected exclusively to the influence of one of these factors. The study indicates that these factors should not be overlooked in assessing technical conditions using sclerometric testing methods. The impact of temperature on sclerometric test results is relatively small; a change in temperature of 10 °C results in an average test outcome change of approximately 3%. Conversely, changing the orientation of the measuring device from horizontal to vertical can alter the test result by up to 10%. The direction of testing relative to the annual increments of wood also has a significant impact on the test results, but incorporating this factor into practice seems to be quite difficult, and in the case of elements with substantial cross-sections, it is also not required. The obtained results enable the application of established correlational relationships in the structural analysis of wooden elements for which access is challenging, especially under temperature conditions different from the reference, 20 °C.

5.
Am J Bot ; 110(10): e16243, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37755870

RESUMO

PREMISE: Dominant in many ecosystems around the world, clonal plants can reach considerable ages and sizes. Due to their modular growth patterns, individual clonal plants (genets) can consist of many subunits (ramets). Since single ramets do not reflect the actual age of genets, the ratio between genet size (radius) and longitudinal annual growth rate (LAGR) of living ramets is often used to approximate the age of clonal plants. However, information on how the LAGR changes along ramets and how LAGR variability may affect age estimates of genets is still limited. METHODS: We assessed the variability of LAGR based on wood-section position along the ramets and on the duration of the growing season on three genetically distinct genets of Salix herbacea growing in the Northern Apennines (Italy). We compared genet ages estimated by dividing genet radius by the LAGRs of its ramets. RESULTS: LAGR increased significantly from the stem apex to the root collar; indicating that ramet growth rate decreased with time. Furthermore, a difference of ca. 2 weeks in the onset of the growing period did not impact LAGR. Considering the high LAGR variability, we estimated that the three genets started to grow between ~2100 and ~7000 years ago, which makes them the oldest known clones of S. herbacea even considering the most conservative age estimate. CONCLUSIONS: Our findings indicate that analyzing ramets at the root collar provides an integrative measurement of their overall LAGR, which is crucial for estimating the age of genets.


Assuntos
Salix , Animais , Ecossistema , Viverridae , Plantas , Itália
6.
Front Plant Sci ; 14: 1183918, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37448865

RESUMO

In tropical and subtropical regions, much research is still required to explore the dendrochronological potential of their trees. This study aims to evaluate the anatomical structure and dendrochronological potential of three Mediterranean desert shrubs in Egypt (Lycium schweinfurthii var. schweinfurthii, L. europaeum, and Calligonum polygonoides subsp. comosum) supported by X-ray density. The results showed that the target species had distinct growth rings at macroscopic and microscopic levels. The vessel traits reflected the adaptability of each species with the prevailing arid climate conditions. After the exclusion of the non-correlated series, we obtained three site chronologies that cover the years 2013-2022 for L. schweinfurthii, 2012-2022 for L. europaeum, and 2011-2022 for C. comosum. The mean series intercorrelation was 0.746, 0.564, and 0.683 for L. schweinfurthii, L. europaeum, and C. comosum, respectively. The EPS (expressed population signal) values ranged from 0.72 to 0.80, while the SNR (species-to-noise ratio) ranged from 9.1 to 21.5. Compiling all series of L. schweinfurthii raised the EPS value to 0.86. The chronologies developed for the studied species were relatively short since we dealt with multi-stemmed shrubs. The average percentage difference between latewood density (LWD) and earlywood density (EWD) in C. comosum, L. europaeum, and L. schweinfurthii were 11.8% ± 5.5, 5.2%± 1.87, and 3.6% ± 1.86, respectively. X-ray densitometry helped in the precise determination of the ring borders of the studied species. The relationships between the radial growth of the studied species and the climate variables were weak to moderate but mostly not significant (i.e., r < 0.7). Generally, the radial growth of the target species had a weak to moderate positive correlation with temperature and precipitation during the wet season (winter), while negatively correlated with temperature for the rest of the year, particularly in summer. Our data agrees with earlier findings that ring formation starts at the beginning of the long vegetative stage, then the rest of the assimilated carbohydrates are directed to the flowering and fruiting at the end of the vegetative stages. For more efficient dendrochronological studies on subtropical and Mediterranean trees, we recommend carrying out xylogenesis studies, collection of phenological data, sampling 45-80 trees per species, using new techniques, and choosing homogeneous and close sites for wood sampling.

7.
Materials (Basel) ; 16(13)2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37445185

RESUMO

The complete characterization of wood, with the determination of the 12 elastic constants that represent its orthotropy, is greatly relevant in applications employing structural calculation software programs. Ultrasound allows for such characterization with relative simplicity when compared to other methods. The polyhedron is considered the most appropriate specimen format for allowing the 12 constants to be calculated with a single specimen, and the traditionally used one is the 26-sided polyhedron, which, to be produced manually with more precision in directing the main directions of the wood, needs larger faces. The accuracy of this technique tends to be reduced when increasing the growth rings' inclination since the waves deviate from the main directions of orthotropy. This research aimed to verify whether it is possible to reduce the polyhedra dimension without affecting the results of the elastic parameters obtained in wood characterization by ultrasound. The results indicate that the dimension of the polyhedron can be reduced without prejudice to the results of the elastic parameters obtained by the ultrasound test and that, in the manual production process of the specimen, the best way to make this reduction is to eliminate the faces unused in the test, changing the polyhedron to 18 faces instead of 26. Reducing the number of faces simplifies the manufacturing process and thus increases the possibility of producing specimens with straighter growth rings and better-directed symmetry axes.

8.
Microsc Res Tech ; 86(9): 1197-1205, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37515361

RESUMO

Panax ginseng, a slow-growing perennial herb, is the most praised and popular traditional medicinal herb. Mountain-cultivated ginseng (MCG) and cultivated ginseng (CG) both belong to Panax ginseng C. A. Meyer. The market price and medical effects of this popular health product are closely related to its age. It is widely acknowledged that CG is typically harvested after 4-6 years of growth, but MCG is often collected after 10 years. Until now, the age identification of MCG or mountain wild ginseng (MWG) has remained a major challenge. In this study, we established a novel and rapid method for staining xylem vessels with phloroglucinol and identifying the "annual growth rings" of ginseng by utilizing a stereoscope, which serves as a reliable indicator of the age of MCG. Statistical analysis of the ring radius and the ring density of MCG aged from 1 to 20 years shows that the secondary xylem of MCG increases rapidly in the first 3 years but then gradually slows down from 4 to 10 years, and minor fluctuation is observed in the next 10 years. Meanwhile, the space between the growth rings (ring density) becomes increasingly small with age. This straightforward staining approach can reveal the age of MCG with remarkable clarity and can distinguish MCG from CG. RESEARCH HIGHLIGHTS: A novel rapid staining method for Panax ginseng was established. The age of mountain-cultivated ginseng (MCG) can be identified by microscopic techniques. MCG and cultivated ginseng (CG) can be discriminated by microstructure characteristics.


Assuntos
Panax , Panax/química
9.
Environ Sci Technol ; 57(23): 8776-8784, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37267390

RESUMO

The potential transformation of hexachlorocyclohexane isomers (HCHs) within tree trunks could have a significant impact on the use of phytoscreening. However, the transformation mechanisms of HCH in trunks particularly in growth rings are not yet well understood. Therefore, a field study on an HCH-contaminated field site was conducted to investigate the fate of HCH, particularly α-HCH in tree trunks using multielement compound-specific isotope analysis (ME-CSIA) and enantiomer fractionation. The results indicate that α-HCH was transformed, as evidenced by higher δ13C and δ37Cl values detected across different growth ring sections and in the bark compared to those in muck and soil. Remarkably, in the middle growth ring section, δ13C values of HCH were only marginally higher or comparable to those in muck, whereas δ37Cl values were higher than those of the muck, indicating a different transformation mechanism. Moreover, the δ37Cl values of ß-HCH also increased in the tree trunks compared to those in soil and muck, implying a transformation of ß-HCH. Additionally, dual-element isotope analysis revealed that there are different transformation mechanisms between the middle growth rings and other sections. Our findings suggest that the transformation of HCHs in trunks could bias quantitative phytoscreening approaches; however, ME-CISA offers an option to estimate the degradation extent.


Assuntos
Hexaclorocicloexano , Árvores , Isótopos de Carbono/análise , Biodegradação Ambiental , Solo
10.
Int J Mol Sci ; 24(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37176062

RESUMO

The chemical composition and structure of bamboo octocoral Keratoisis spp. skeletons were investigated by using: Scanning Electron Microscopy SEM, Raman Microscopy, X-ray Diffraction XRD, Laser Ablation-Inductively Coupled Plasma LA-ICP, and amino acid analyzers. Elements discovered in the nodes (mainly organic parts of the skeleton) of bamboo corals showed a very interesting arrangement in the growth ring areas, most probably enabling the application of bamboo corals as palaeochronometers and palaeothermometers. LA-ICP results showed that these gorgonian corals had an unusually large content of bromine, larger than any other organism yet studied. The local concentration of bromine in the organic part of the growth rings of one of the studied corals grew up to 29,000 ppm of bromine. That is over 440 times more than is contained in marine water and 35 times more than Murex contains, the species which was used to make Tyrian purple in ancient times. The organic matter of corals is called gorgonin, the specific substance that both from the XRD and Raman studies seem to be very similar to the reptile and bird keratins and less similar to the mammalian keratins. The missing cross-linking by S-S bridges, absence of aromatic rings, and significant participation of ß-turn organization of peptides differs gorgonin from keratins. Perhaps, the gorgonin belongs to the affined but still different substances concerning reptile and bird keratin and in relation to the more advanced version-the mammalian one. Chemical components of bamboo corals seem to have great medical potential, with the internodes as material substituting the hard tissues and the nodes as the components of medicines.


Assuntos
Antozoários , Animais , Antozoários/química , Bromo , Mamíferos , Microscopia Eletrônica de Varredura , Água , Espectrometria de Massas , Difração de Raios X , Microscopia
12.
Crit Rev Food Sci Nutr ; 63(20): 4799-4816, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34847797

RESUMO

Starch is a major part of the human diet and an important material for industrial utilization. The structure of starch granules is the subject of intensive research because it determines functionality, and hence suitability for specific applications. Starch granules are made up of a hierarchy of complex structural elements, from lamellae and amorphous regions to blocklets, growth rings and granules, which increase in scale from nanometers to microns. The complexity of these native structures changes with the processing of starch-rich ingredients into foods and other products. This review aims to provide a comprehensive review of analytical methods developed to characterize structure of starch granules, and their applications in analyzing the changes in starch structure as a result of processing, with particular consideration of the poorly understood short-range ordered structures in amorphous regions of granules.


Assuntos
Alimentos , Amido , Humanos , Amido/química
13.
J Fish Biol ; 101(4): 985-995, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35817955

RESUMO

Fish eye lenses are a protein-based chronological recorder of microchemical constituents that are a potentially useful tool for interpretations of environmental, ecological and life-history experienced by fish. Here, we present the first study with data on the chemical composition of eye lenses from Baltic cod examined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and compare these spatially resolved data to otoliths from the same fish also analysed by LA-ICPMS, measuring the isotopes 27 Al, 137 Ba, 43 Ca, 52 Cr, 65 Cu, 57 Fe, 39 K, 7 Li, 25 Mg, 55 Mn, 31 P, 208 Pb, 85 Rb, 45 Sc, 29 Si, 88 Sr, 47 Ti, 50 V, 149 Yb, 66 Zn and 90 Zr. Comparison of the variation in element concentrations between eye lenses and otoliths from the same individuals showed minor similarities, suggesting a different governance in the uptake processes. A strong overlap between the concentric growth rings in the eye lenses and the otolith Sr periodicity was observed, where each consecutive minima in the chemical profile with high accuracy correspond to the width of each lens ring. No comparable trends were seen between growth rings and all other elements measured from both lenses and otoliths. The characteristic rings observed in cod eye lenses do not seem to represent seasonal fluctuation nor are they found to be directly linked to age. With this research, we provide a baseline study identifying elements in corresponding eye lenses and otoliths that show potential for unravelling the environmental and biological conditions experienced by fish.


Assuntos
Membrana dos Otólitos , Oligoelementos , Animais , Membrana dos Otólitos/química , Chumbo/análise , Peixes , Oligoelementos/análise
14.
Data Brief ; 38: 107447, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34660861

RESUMO

Although Pinus kesiya (Royle ex Gordon) is endemic to South Asia, where it grows naturally in pure stands, its growth trajectory in Zambia has not been evaluated. It is estimated that half of the P. kesiya plantation total area is found close to the Copper mine smelters, and the other half is in remote locations approximately 30 km away from the mining activities. Variation in tree growth of non-native P. kesiya forests between these locations in Zambia has been observed, but the causes are unknown. We tested the hypotheses that (i) P. kesiya annual tree-rings are cross-datable, (ii) the signals and noise in the growth ring patterns are modulated by variations in precipitation, temperature, solar radiation, and site conditions. We collected data from 67 trees growing close to the emission source and also in the location 30 km away. Site-specific tree ring-width data was collected and chronology built for P. kesiya. We present ring-width chronology data that may be used to infer the radial growth periodicity of P. keskya at each site. The re-use potential of the data presented includes developing carbon sequestration, yield, and growth models and assessing forest resilience to climate change. It is also intended to enhance the understanding of tree growth and productivity dynamics of non-native pine species. See the article "Assessing cross-datable distinct annual growth rings in non-native Pinus kesiya Royle ex Gordon in Zambia" for more information.

15.
Rev. biol. trop ; 69(3)sept. 2021.
Artigo em Espanhol | LILACS, SaludCR | ID: biblio-1387680

RESUMO

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.


Assuntos
Cronologia , Quercus/crescimento & desenvolvimento , Clima
16.
Ann Bot ; 127(3): 337-346, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33211793

RESUMO

BACKGROUND AND AIMS: Forest peatlands represent 25 % of global peatlands and store large amounts of carbon (C) as peat. Traditionally they have been drained in order to increase forestry yield, which may cause large losses of C from the peat. Rewetting aims to stop these losses and to restore the initial storage function of the peatlands. As roots represent major peat-forming elements in these systems, we sampled roots with diameter <5 mm in a drained and a rewetted forest peatland in north-east Germany to evaluate differences in tree biomass investments below ground, root functional characteristics and root age. METHODS: We cored soil next to Alnus glutinosa stems and sorted root biomass into <1, 1-2 and 2-5 mm diameter classes. We measured biomass distribution and specific root area (SRA) in 10-cm depth increments down to 50 cm, and estimated root age from annual growth rings. KEY RESULTS: Root biomass in the rewetted site was more than double that in the drained site. This difference was mostly driven by very fine roots <1 mm, which accounted for 51 % of the total root biomass and were mostly (75 %) located in the upper 20 cm. For roots <1 mm, SRA did not differ between the sites. However, SRA of the 1-2 mm and 2-5 mm diameter roots was higher in the drained than in the rewetted site. Root age did not differ between sites. CONCLUSIONS: The size-dependent opposite patterns between root biomass and their functional characteristics under contrasting water regimes indicate differences between fine and coarse roots in their response to environmental changes. Root age distribution points to similar root turnover rates between the sites, while higher root biomass in the rewetted site clearly indicates larger tree C stocks below ground under rewetting, supporting the C sink function of the ecosystem.


Assuntos
Alnus , Biomassa , Ecossistema , Florestas , Raízes de Plantas , Solo
17.
PeerJ ; 8: e9506, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32832261

RESUMO

BACKGROUND: Forest plantations play an important role in carbon sequestration, helping to mitigate climate change. In this study, survival, biomass, growth rings and annual carbon content storage were evaluated in a mixed Pinus durangensis and P. cooperi plantation that was established after a clear-cutting. The plantation is eight years old and covers an area of 21.40 ha. METHODS: Sixteen sites of 100 m2 were distributed randomly. At each site, two trees distributed proportionally to the diametric categories were destructively sampled (one per tree species). Two cross-sections were cut from each tree: The first at the base of the stump and the second at 1.30 m. The width of tree rings of the first cross-section was measured using a stereoscopic microscope with precision in microns (µm). The year-by-year basal diameter of each tree was recorded and biomass and carbon content was estimated using allometric equations. RESULTS: The estimated survival was 75.2%. The results of the ANOVA showed significant differences between the year-by-year width records of tree rings, the highest value corresponding to the fifth year. The average carbon sequestration per year is 0.30 kg for both studied tree species. CONCLUSIONS: P. durangensis and P. cooperi plantations adapt and develop well in Durango forests when they are established in areas that are subjected to clear-cutting.

18.
Chin J Nat Med ; 18(6): 460-471, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32503737

RESUMO

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.


Assuntos
Astrágalo/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Flavonoides/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Saponinas/farmacologia , Animais , Astragalus propinquus , Modelos Animais de Doenças , Doxorrubicina , Raízes de Plantas/química , Ratos , Ratos Sprague-Dawley
19.
Environ Pollut ; 261: 114209, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32220752

RESUMO

Little is known about how forests adjust their gas-exchange mode while atmospheric CO2 rises globally and air quality changes regionally. The present study aims at addressing this research gap for boreal spruce trees growing in three different regions of Canada, submitted to distinct levels of atmospheric emissions, by examining the amount of carbon gained per unit of water lost in trees, i.e., the intrinsic water use efficiency (iWUE). Under pristine air quality conditions, middle-to long-term trends passed from no-reaction mode to passive strategies due to atmospheric CO2, and short-term iWUE variations mostly ensue from year-to-year climatic conditions. In contrast, in trees exposed to pollutants from a copper smelter and an oil-sands mining region, air quality deterioration generated swift, long-term iWUE rises immediately at the onset of operations. In this case, the very active foliar strategy sharply reduced the intra-foliar CO2 (Ci) pressure. Statistical modeling allowed identifying emissions as the main trigger for the iWUE swift shifts; subsequent combined effects of emissions and rising CO2 led to passive foliar modes in the recent decades, and short-term variations due to climatic conditions appeared all along the series. Overall, boreal trees under different regional conditions modified their foliar strategies mostly without changing their stem growth. These findings underline the potential of acidifying emissions for prompting major iWUE increases due to lowering the stomatal apertures in leaves, and the combined influence of rising CO2 in modulating other foliar responses. A fallout of this research is that degrading air quality may create true divergences in the relationship between tree-ring isotopes and climatic conditions, an impact to consider prior to using isotopic series for paleo-climatic modeling.


Assuntos
Poluição do Ar , Picea , Canadá , Dióxido de Carbono/toxicidade , Isótopos de Carbono/análise , Picea/efeitos dos fármacos , Picea/fisiologia
20.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-827224

RESUMO

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.

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