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1.
María Xesús Gómez-Rey Manuel Madeira João Coutinho 《European Journal of Forest Research》2013,132(2):281-295
Wood ash addition to forest soils can balance exported nutrients by tree harvesting and decrease soil acidity, but its effectiveness in Mediterranean areas has been scarcely evaluated. The aim of the present study was to assess the effects of wood ash application on soil C and N dynamics, nutrient leaching and fertility in a pine stand. Treatments were loose and pelleted ash application (11 Mg ha?1), alone or combined with N fertilizer, and a control treatment. Nutrient leaching and soil chemical and biological properties were periodically evaluated for a 30-month period. Wood ash increased leaching of base cations (Ca, Mg, Na and K) and P, mainly at the beginning of the study. The effect was more pronounced for the loose formulation. As a consequence, a positive effect on soil nutrient availability (exchangeable base cations and extractable P) and soil acidity reduction was observed for the loose formulation in the 0–10-cm soil layer. Carbon and N dynamics were only affected when ash was applied with N fertilizer, which enhanced CO2 flux during the study period. 相似文献
2.
Context
Warmer temperatures and anthropogenic N depositions are altering soil nutrient cycles and plant nutrition worldwide and are projected to rise dramatically in the future, particularly at the high latitudes. How much will such alterations affect symbiotic organisms such as ectomycorrhizae (ECM)?Aims
The aim was to investigate the short-term effects of warmer soil temperatures and N-enriched precipitations on roots and ECM.Methods
A field experiment was established during 2008–2010 in two black spruce (Picea mariana) stands of the boreal forest of Quebec, Canada. The ECM of 12 trees per site were counted and identified by morphotyping.Results
After 3 years, soil heating markedly modified the proportions of vital root tips and ECM in the colder stand, while no effect of the N-enriched rain was observed on soil chemistry and consequently on roots and ECM. Density and ramification of root tips were not affected by the treatments.Conclusion
The hypothesis that the treatments would alter the ECM was confirmed only partially in the colder stand. The type of application and amount of N supplied were unable to substantially modify in the short-term growth conditions of roots and ECM, explaining the observed results. 相似文献3.
Dehai Zhao Michael Kane Robert Teskey Daniel Markewitz Dale Greene Bruce Borders 《Annals of Forest Science》2014,71(8):843-851
Context
To sustainably manage loblolly pine plantations for bioenergy and carbon sequestration, accurate information is required on the relationships between management regimes and energy, carbon, and nutrient export.Aims
The effects of cultural intensity and planting density were investigated with respect to energy, carbon, and essential nutrients in aboveground biomass of mid-rotation loblolly pine plantations, and the effects of harvesting scenarios on export of nutrients were tested.Methods
Destructive biomass sampling of a 12 years-old loblolly pine culture/density experiment, and analysis of variance were used to assess the effects of cultural intensity (operational vs. intensive) and six planting densities ranging from 741 to 4,448 trees ha?1. Two harvesting scenarios (stem-only vs. whole-tree harvesting) were assessed in terms of energy, carbon, and nutrient export.Results
The concentrations of energy, carbon, and nutrients varied significantly among stem wood, bark, branch, and foliage components. Cultural intensity and planting density did not significantly affect these concentrations. Differences in energy, carbon and nutrient contents among treatments were mainly mediated by changes in total biomass. Nutrient contents were affected by either cultural intensity or planting density, or both. Stem-only harvesting removed 71–79 % of aboveground energy and carbon, 29–45 % of N, 28–44 % of P, 44–57 % of K, 51–65 % of Ca, and 50–61 % of Mg.Conclusions
Stem-only harvesting would be preferred to whole-tree harvesting, from a site nutrient conservation perspective. 相似文献4.
Eitaro Fukatsu Miyoko Tsubomura Yoshitake Fujisawa Ryogo Nakada 《Annals of Forest Science》2013,70(5):451-459
Context
Wood density is an important component of wood quality, and it is therefore important to assess whether it can be subject to genetic improvement.Aim and methods
We assessed the potential for genetic improvement of wood density in Larix kaempferi by recording components of annual growth rings. A full diallel mating test based on six plus L. kaempferi trees was used. Trees were 29 years old. Wood density was recorded by soft X-ray densitometry, and genetic parameters and genetic gains were computed.Results
Wood density of mature wood was highly heritable, and the largest heritability (0.78) was reached at age 25. Specific combining ability and reciprocal effects displayed very low variance. The age–age correlation of overall wood density was very high (>0.94). The genetic correlation between overall wood density and basal cross-sectional area was positive after age 10. Early selection at age 6 would account for 69 % of the genetic gain from direct selection at age 28 in terms of wood density.Conclusion
Genetic improvement of wood density could be achieved by mass selection and a simultaneous selection for radial increment in L. kaempferi; early selection for wood density can be achieved in this species. 相似文献5.
Context
Short rotation coppice (SRC) of hybrid Eucalyptus has been developed in France for almost 30 years for the production of pulp and paper and, since a few years, for energy purposes. In the traditional pulp production, only the stems are harvested, whereas the whole biomass may be harvested for energy purposes. Thus, a range of different harvest scenarios need to be considered with higher plantation densities or younger age of harvest for example.Aims
The objective of this study was to build models to estimate biomass and nutrient content of eucalyptus at different ages and so to estimate the production and the nutrient exportation of a SRC, depending on the different harvest scenarios.Methods
Over 250 trees were sampled in 16 stands at ages from 1 to 15 years. For each tree, biomass of different compartments and nutrient contents were recorded.Results
A complete set of equations for the four compartments (wood, bark, branches, and leaves) of aboveground biomass and for nutrient concentration was set up.Conclusion
Biomass and its allocation to different compartments and nutrient concentrations depended on the dimension and/or the age of the tree. In particular, nutrient concentration decreased with increasing tree diameter. 相似文献6.
7.
Variation of wood color parameters of Tectona grandis and its relationship with physical environmental factors 总被引:1,自引:0,他引:1
? Context
Teak??s wood color is considered an important attribute in the marketing phase and it has been influenced by environmental setting, stand conditions and management, plant genetic source, and age. However, there is a lack of understanding about how the environmental factors might affect the teak??s wood color planted in short-rotation forest plantations.? Aims
The aim of this study is to understand the relationship, gathered from generated information, between edaphic and climatic variables and their effects in the wood color variation of Tectona grandis from trees in forest plantations.? Methods
Twenty-two plots were grouped in five cluster sites that shared similar climatic and soil conditions. Data about soil??s physical?Cchemical properties and climatic variables were collected and analyzed. Representative trees were harvested next to each plot in order to obtain a wood sample per tree at a diameter breast height. Wood color was measured using standardized CIELab??s chromaticity system.? Results
After comparing the wood change color index (?E*) in the five studied clusters, it was found that heartwood produced from drier and fertile sites had more yellowish-brown color. The heartwood b* color index resulted with significant correlations (R?>?0.5, P?<?0.05) among nine climatic and eight edaphic variables.? Conclusion
It was concluded that climatic variables should be considered as the first-order causal variables to explain wood color variation. Hence, darker b* wood color was associated with dry climates; also, with deeper and fertile sites. 相似文献8.
Fire severity as a key factor in post-fire regeneration of Pinus pinaster (Ait.) in Central Portugal
Context
Mediterranean pine woodlands are strongly affected by wildfires; however, there are knowledge gaps in the role of fire severity on Pinus pinaster Ait. regeneration.Objectives
The principal questions were: (a) does post-fire regeneration of Maritime Pine differ where canopies were consumed to a low vs. high degree and (b) which factors, besides fire severity, could explain these differences.Methods
Pine recruitment was monitored from 2 to 36?months after a summer wildfire in 18 25?m2 plots, equally divided over two fire severity classes based on crown consumption. Besides the degree of crown consumption, three quantitative fire severity indices as well as post-fire site conditions, seed input and understory vegetation recovery were measured.Results
Pine seedling densities were consistently higher in the plots with low than high crown consumption but due to marked spatial variability, they were only significantly different at two out of the eight sampling occasions. This variability could be explained by a quantitative index based on the diameter of twigs, as well as by seed input and post-fire site conditions (ash and litter cover).Conclusion
Fire severity was found to strongly affect the pine recruitment following wildfire, using both a qualitative visual severity index and a quantitative, more labour-intensive one. 相似文献9.
10.
Giovanni Di Matteo Irene Tunno Pierfrancesco Nardi Paolo De Angelis Giada Bertini Gianfranco Fabbio 《Annals of Forest Science》2014,71(8):885-895
Context
Harvesting of Mediterranean oak coppice forests has been progressively suspended on a share of cover over the last decades. Positive growth trend in outgrown coppices no longer harvested on short rotations now drives natural forest restoration on wide areas, and it represents a potential carbon sink in view of global warming.Aims
Our goals were to estimate carbon (C) and nitrogen (N) content per compartment in two deciduous oak outgrown coppice forests, aged differently and growing under unequal site quality, to verify whether C concentration across compartments is in agreement with the conventional conversion rate of 0.5.Methods
Ecosystem C and N pools were assessed by multiplying the whole coppice mass (combining specific allometric functions, root-to-shoot ratio, and soil sampling) by respective C and N concentrations.Results
The results point out that the largest percentage of N was stored in 15-cm topsoil (84.06 and 73.34 % at the younger and older site, respectively), whereas the proportion of organic ecosystem C pool was more variable, as a consequence of the amount and allocation of phytomass. We found that, in most cases, C concentration was less than the conventional conversion rate of 0.5, especially in deadwood, O layer, and root compartments.Conclusion
The findings provide further knowledge of C and N storage into these new built-up forest types and the evidence that a detailed analysis may get higher accuracy in the pools estimate, producing a more reliable outlook on dynamics and climate change mitigation ability of these systems. 相似文献11.
Variations of wood basic density with tree age and social classes in the axial direction within Pinus massoniana stems in Southern China 总被引:1,自引:0,他引:1
Xiangwen Deng Liyun Zhang Pifeng Lei Wenhua Xiang Wende Yan 《Annals of Forest Science》2014,71(4):505-516
Context
Reliable estimates of wood density (WD) within individual trees could maximize the value of Pinus massoniana for specific end-use.Aim
We examined and quantified the axial patterns of WD in trees with different social status in the stands.Methods
Wood disks were sampled at the bottom, breast height, and middle of each 1-m sections from 108 stems, harvesting from three social classes in subtropical forests. A mixed-effects model was designed to quantify axial variation.Results
The WD at different height was significantly different from the whole-stem WD (WWD) except the relative height of 0.1. An overall decrease of 133.8 kg m?3 in WD was found from stem base to top. WD was significantly influenced by relative heights, tree age, and social class. WD of each relative height in mature trees was significantly higher than that of younger trees. Tree social class can affect WD development in the axial direction at age classes 2 and 3. Combining the fixed plus random effects, the final model explained 91 % of the observed variation in WD.Conclusion
The WD development patterns in the axial direction vary considerably among tree age, diameter at breast height, and social class. To distinguish and supply timber for specific end-uses, we should use the axial variation in disk WD (DWD) instead of WWD directly. The accurate predictions of WD provided by the model could be used to optimally classify logs into different product classes and maximize economic benefits. We can use DWD at the relative height of 0.1 instead of WWD of a single tree. 相似文献12.
Xianfeng Yi Guoqiang Liu Mingming Zhang Zhong Dong Yueqin Yang 《Annals of Forest Science》2014,71(1):43-49
Context
Although various tracking methods have been used in many ecosystems to investigate seed dispersal and seedling recruitment, it is still difficult to measure seed dispersal patterns due to methodological challenges in tracking seed movement away from parent trees and in finding the locations of seedlings.Aim
Here, we aimed to develop a new approach to track seed dispersal by animals in the field.Methods
Our approach involves soaking seeds directly into 15N-urea solutions with different dosages to enrich them isotopically. This new method is expected to create a reliable differentiation between the enriched seeds and natural ones and consequently between the corresponding seedlings.Results
We showed that acorns of Quercus variabilis and Cyclobalanopsis glauca and seeds of Pinus koraiensis soaked in 15N-urea solutions were successfully enriched. We did not find that δ 15N value of seeds was a linear function of 15N-urea soaking duration. However, with high urea dosage and extending soaking duration, the δ 15N values in seedlings of Q. variabilis and P. koraiensis were higher than those of normal plants. As expected, 15N isotope was significantly diluted in the growing seedlings germinated from 15N-enriched seeds. Using the 15N-urea soaking method, we successfully located five seedlings of Q. variabilis germinated from the enriched acorns in the field.Discussion
The 15N-urea soaking technique is powerful in tracking seed dispersal and seedling recruitment. This new method solves some of the problems inherent in traditional methods for tracking secondary seed dispersal and could further improve the study of seed dispersal ecology. 相似文献13.
? Context
The rising demand of energy wood for heating purposes in Germany leads to concerns regarding the overexploitation of forests. A major aspect is the impact of whole-tree harvesting on long-term productivity of forest soils.? Aims
This study aimed to analyze the effects of nutrient removal on productivity using the historically prevalent practice of litter raking. Since there is a lack of controlled whole-tree harvesting experiments in Germany, we used litter raking as a surrogate management practice entailing the removal of nutrients from forest stands.? Methods
We used three sites with documented litter raking to analyze the effects of nutrient removal on productivity using dendroecological methods: two recent litter removal experiments in two Scots pine stands (Siegenburg and Burglengenfeld) and one oak stand (Eichhall) with documented historic litter raking. Basal area increment (BAI) and tree-ring characteristics were compared between periods with litter raking and the preceding periods for both treatment and control plots.? Results
For the two Scots pine sites with a relatively short litter raking period, no effects of litter raking on BAI could be ascribed to nutrient removal. On the oak site with a longer history of litter utilization, the loss in BAI due to litter raking amounts to 22 % during the period with active raking and to still 17 % in the recovery period.? Conclusions
These results contribute to the still very limited understanding about the impact of whole-tree harvesting on forest productivity in Germany by laying down an upper limit of possible effects due to nutrient removal, as nutrient loss by litter raking tends to be higher than nutrient loss by whole-tree harvesting. 相似文献14.
Youtao Si Li Xiong Yuehmin Chen Jinmao Zhu Jinsheng Xie Ren Gao Yusheng Yang 《Annals of Forest Science》2018,75(3):79
Key message
The vertical transport of dissolved organic carbon (DOC) is an important determinant of carbon distribution across a soil profile. The transport of DOC down a soil profile can be largely influenced by incoming DOC and soil organic carbon (SOC) levels, which insulate DOC from adsorption processes regulated by soil texture and Fe/Al mineralogy.Context
Uncertainties about how soil properties affect DOC transport through the soil profile require study because soils can differ strongly with respect to texture or Fe/Al mineralogy and yet retain similar quantities of DOC.Aims
This study aimed to assess the role of incoming DOC and native SOC in regulating DOC migration in soils and investigate the contribution of DOC movement to SOC allocation.Methods
We leached a standard DOC solution extracted from Castanopsis carlesii litter through two distinct soil types, using two leaching strategies: single leaching and sequential leaching. The two soil types under a natural Castanopsis carlesii (Hemsl.) Hayata forest and a natural Castanopsis fargesii Franch. forest, respectively, differ strongly with respect to soil texture, Fe/Al oxide abundances, and SOC nature.Results
With single leaching, where each of six soil layers making up an entire 0–100-cm soil depth profile received single doses of standard DOC solution, deeper soil layers retained more DOC than upper soil layers, with native SOC largely masking the effects of soil texture and Fe/Al mineralogy on DOC migration. Following sequential leaching, where a sixfold larger amount of standard DOC solution sequentially percolated through the six soil layers, the upper soil layers generally retained more DOC than deeper layers. Nevertheless, in sequential leaching, desorption-induced transfer of carbon from upper soil layers to deeper soil layers resulted in greater total carbon retention than in single leaching.Conclusion
Forest subsoils (40–100 cm) are well below C saturation, but DOC vertical movement from top soils only transfers limited organic carbon to them. However, DOC vertical movement may greatly alter SOC allocation along the top soil profile (0–40 cm), with part of outer sphere native SOC displaced by incoming DOC and migrating downwards, which is a natural way to preserve SOC.15.
Alma M. García-Moreno María D. Carbonero-Muñoz María Serrano-Moral Pilar Fernández-Rebollo 《Annals of Forest Science》2014,71(8):917-926
Context
Mediterranean open woodlands (dehesa) have faced a dual process of intensification and abandonment of grazing which has resulted in alteration of the understory vegetation.Aims
We analysed the effects of land use changes on the physiological status of holm oak in different open woodlands (dehesa) in southern Iberian Peninsula.Methods
In an area of extensive grazing, we selected six paired plots (one grazed, one abandoned) and grouped them by habitat types according to understory composition (nearly all monospecific Cistus ladanifer L. shrub or mixed shrub). Six plots of moderate and heavy grazing intensity were chosen within a settled area of livestock use. Shoot growth, macronutrient concentrations and water content were assessed in samples of holm oak leaves.Results
Abandonment of grazing affected some nutrient concentrations and water content of holm oak leaves, but the effects were different according to habitat type. C. ladanifer shrub reduced N and P concentrations and water content while mixed shrub increased P concentration and water content. High grazing intensity improved shoot growth and leaf N and Mg concentrations.Conclusion
Extensive grazing could be a useful management tool to enhance growth, nutritional and water status of holm oak in a habitat with limited resources such as Mediterranean open woodlands (dehesa). 相似文献16.
Florence Maunoury-Danger Nicolas Chemidlin Prevost Boure Jérôme Ngao Daniel Berveiller Claude Brechet Eric Dufrene Daniel Epron Jean-Christophe Lata Bernard Longdoz Caroline Lelarge-Trouverie Jean-Yves Pontailler Kamel Soudani Claire Damesin 《Annals of Forest Science》2013,70(2):173-183
? Context
The carbon isotope composition of the CO2 efflux (δ13CE) from ecosystem components is widely used to investigate carbon cycles and budgets at different ecosystem scales. δ13CE, was considered constant but is now known to vary along seasons. The seasonal variations have rarely been compared among different ecosystem components.? Aims
We aimed to characterise simultaneously the seasonal dynamics of δ13CE in different compartments of two temperate broadleaved forest ecosystems.? Methods
Using manual chambers and isotope ratio mass spectrometry, we recorded simultaneously δ13CE and δ13C of organic matter in sun leaves, current-year twigs, trunk bases and soil in an oak and a beech forest during 1 year.? Results
In the two forests, δ13CE displayed a larger variability in the tree components than in the soil. During the leafy period, a pronounced vertical zonation of δ13CE was observed between the top (sun leaves and twigs with higher values) and bottom (trunk and soil with lower values) of the ecosystem. No correlation was found between δ13CE and δ13C of organic matter. Causes for these seasonal variations and the vertical zonation in isotope signature are discussed.? Conclusion
Our study shows clear differences in values as well as seasonal dynamics of δ13CE among different components in the two ecosystems. The temporal and local variation of δ13CE cannot be inferred from organic matter signature or CO2 emission rates. 相似文献17.
Carmen Sotelo Montes John C. Weber Dimas A. Silva Clarice Andrade Graciela I. B. Mu?iz Rosilei A. Garcia Antoine Kalinganire 《Annals of Forest Science》2012,69(6):747-756
? Context
There is little information about inter- and intra-specific variation in fuelwood properties of trees/shrubs in West Africa.? Aims
We studied variation in fuelwood properties of Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum, and Zizyphus mauritiana in the Sahelian and Sudanian ecozones of Mali.? Methods
Trees were sampled on different soil (sandy, sandy/loam, or rocky), land use (parkland agroforest or woodland), and terrain (flat, temporarily flooded, or hill slope) types in five regions extending from the drier eastern to the more humid western parts of Mali. Basic density, volatile matter, fixed carbon, ash content, moisture content, gross calorific value, and fuel value index were measured for each tree and adjusted for tree age.? Results
All fuelwood properties differed significantly among species, but there were significant species by region interactions. Most fuelwood properties of four species differed significantly among regions. Soil and/or land use type had significant effects on a few fuelwood properties of four species.? Conclusion
In general, fuelwood production is recommended in all regions for G. senegalensis, in drier regions for B. aegyptiaca and C. glutinosum, in more humid regions for Z. mauritiana, and on rocky soils for all species. Fuelwood production of P. reticulatum is not recommended. 相似文献18.
19.
Soil enzyme activities as potential indicators of soluble organic nitrogen pools in forest ecosystems of Northeast China 总被引:1,自引:0,他引:1
Context
Soluble organic nitrogen is considered to reflect the effect of forest types on soil nitrogen status. As a major process affecting the soil-soluble organic nitrogen pool, degradation of insoluble organic nitrogen in the production of soluble organic nitrogen is mediated by a suite of soil enzymes.Aims
This study aims to examine soil-soluble organic nitrogen pools and their relationships with the activities of soil enzymes in natural secondary forest stands and adjacent larch plantation stands.Methods
Four pairs of larch plantation stands and secondary forest stands were randomly selected from a mountainous area, and the top 15?cm of the mineral soils were sampled from each field.Results
The soil-soluble organic nitrogen concentrations were up to 2-fold greater in the secondary forest stands than in the larch plantation stands, whereas the ratio of soluble organic nitrogen/total nitrogen was comparable between the two forest types. The concentrations of soluble organic nitrogen were positively correlated with approximately 2-fold differences in urease and protease activities, a 1.2-fold difference in N-acetyl-??-glucosaminidase and a 1.7-fold difference in l-asparaginase between the two forest types.Conclusions
Our results suggest that relationships between soil-soluble organic nitrogen and enzyme activities are independent on sampling time, and that the soil enzyme activities can be used as potential indicators of soil soluble organic nitrogen pools in the temperate forest ecosystem. 相似文献20.