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1.
Li-Na Xie Hong-Yu Guo Zhe Liu Christopher A. Gabler Wei-Zhong Chen Song Gu Cheng-Cang Ma 《Annals of Forest Science》2017,74(4):70
Key message
Mature Caragana stenophylla shrubs facilitated intraspecific sapling establishment by two mechanisms: microhabitat amelioration and protection against herbivory. Facilitation was mediated by climate, grazing, and sapling age.Context
Pre-existing shrubs could facilitate sapling establishment of woody plants; however, how these facilitation vary across abiotic and biotic stress gradients and the underlying mechanisms remain unclear.Aims
The aim of this study is understanding the facilitation of shrub on sapling establishment and how the two underlying mechanisms, microhabitat amelioration and protection against herbivory, vary across climatic aridity gradients, grazing gradients, and sapling age.Methods
We conducted field sowing experiments to examine the facilitation of mature Caragana stenophylla Pojark on intraspecific sapling establishment.Results
Facilitation of C. stenophylla on sapling survival increased as drought stress, grazing intensity, and sapling age increased. Microhabitat amelioration increased as drought stress and sapling age increased. Similarly, protection against herbivory increased as drought stress, grazing intensity, and sapling age increased. Relative importance of microhabitat amelioration increased as drought stress increased, and relative importance of protection against herbivory increased as grazing intensity and sapling age increased.Conclusion
Facilitation of shrub on sapling establishment involves both microhabitat amelioration and protection against herbivory. Facilitation, the two mechanisms, and relative importance between the two mechanisms would all be affected by climatic aridity, grazing intensity, and sapling age. Shrub establishment has a positive feedback effect.2.
Marcin K. Dyderski Anna Gazda Mariusz Hachułka Paweł Horodecki Izabela L. Kałucka Jacek Kamczyc Marek Malicki Remigiusz Pielech Michał Smoczyk Maciej Skorupski Sylwia Wierzcholska Andrzej M. Jagodziński 《Annals of Forest Science》2018,75(4):91
? Key message
Natural regeneration of P. abies (L.) H. Karst. may reach high densities in lower mountain elevations. The highest densities were found in sites with moderate light availability, with low pH, and not near the riverbank. However, age-height classes differed in the predicted magnitude of response, but were consistent in response directions. Mosses and understory species typical of coniferous forests were positively correlated with regeneration density.? Context
Norway spruce Picea abies (L.) H. Karst. in Central Europe is at risk under climate change scenarios, particularly in mountain regions. Little is known about the impact of environmental factors on the natural regeneration of P. abies in low-elevation mountain forests.? Aims
We aimed to assess impacts of distance from the riverbank, soil pH, and light availability on natural P. abies regeneration. We hypothesized that (1) natural P. abies regeneration would depend on light availability and soil pH and (2) there are understory plant species which may indicate the microsites suitable for natural regeneration of P. abies.? Methods
The study was conducted in the Sto?owe Mountains National Park (SW Poland, 600–800 m a.s.l.). We established 160 study plots (25 m2) for natural regeneration, light availability, soil pH, and understory vegetation assessment.? Results
The highest densities of natural regeneration of P. abies were observed in sites with moderate light availability (0.1–0.2 of open sky) and low pH (3.5–4.5), and located relatively far from the riverbank. Cover of 22 understory plant species were correlated with natural P. abies regeneration densities, mostly positively.? Conclusion
Different stages of natural regeneration of P. abies revealed different regeneration niches. Most understory plant species (bryophytes and herbs typical of coniferous forests) do not compete with natural regeneration of P. abies.3.
Key message
Carbon stock density was quite similar in planted vs natural forest of Masson’s pine ( Pinus massoniana Lamb.) in China across three ages (7, 15, and 50 years). The stock in the standing trees was larger in planted than in natural forests, but this difference was compensated by larger stocks in the soil and the debris of natural forests.Context
Most studies on the carbon stocks are focused on management strategies to maximize carbon stocks. We still lack data comparing planted vs natural conifer forests.Aims
We compared carbon storage in the different compartment (vegetation, soil, debris) along a chronosequence of Masson’s pine plantations vs natural forests.Methods
We investigated 58 Masson’s pine (Pinus massoniana Lamb.) forest stands (20 m?×?50 m plots), that differ in stand management (planted and natural forests) and age (young, middle-aged, and mature ages) and then calculated the carbon stock densities of vegetation biomass (tree, shrub, and herb), debris, and soil.Results
The carbon stock densities in the planted and natural Masson’s pine forest ecosystems ranged from 78 to 210 Mg ha?1 and from 97 to 177 Mg ha?1 respectively. The carbon stock densities in the vegetation were significantly greater in planted forests than in natural forests. A lower carbon stock density in debris and soil alleviated the increase of biomass carbon stock densities in planted vs natural forests, leading to similar carbon stock densities at ecosystem level. The carbon stock densities in the vegetation increased with age, whereas those of debris and soil remained stable.Conclusions
Planted forests of Masson’s pine sequester similiar amounts of carbon at ecosystem level to those in natural forests, reinforcing the idea that planted pine forests can contribute to the mitigation of greenhouse gas emission.4.
María Castaño-Díaz Pedro Álvarez-Álvarez Brian Tobin Maarten Nieuwenhuis Elías Afif-Khouri Asunción Cámara-Obregón 《Annals of Forest Science》2017,74(4):69
Key message
LiDAR data (low-density data, 0.5 pulses m ?2 ) represent an excellent management resource as they can be used to estimate forest stand characteristics in short-rotation willow coppice (SRWC) with reasonable accuracy. The technology is also a useful, practical tool for carrying out inventories in these types of stands.Context
This study evaluated the use of very low-density airborne LiDAR (light detection and ranging) data (0.5 pulses m?2), which can be accessed free of charge, in an SRWC established in degraded mining land.Aims
This work aimed to determine the utility of low-density LiDAR data for estimating main forest structural attributes and biomass productivity and for comparing the estimates with field measurements carried out in an SRWC planted in marginal land.Methods
The SRWC was established following a randomized complete block design with three clones, planted at two densities and with three fertilization levels. Use of parametric (multiple regression) and non-parametric (classification and regression trees, CART) fitting techniques yielded models with good predictive power and reliability. Both fitting methods were used for comprehensive analysis of the data and provide complementary information.Results
The results of multiple regression analysis indicated close relationships (Rfit 2 = 0.63–0.97) between LiDAR-derived metrics and the field measured data for the variables studied (H, D20, D130, FW, and DW). High R 2 values were obtained for models fitted using the CART technique (R 2 = 0.73–0.94).Conclusion
Low-density LiDAR data can be used to model structural attributes and biomass yield in SRWC with reasonable accuracy. The models developed can be used to improve and optimize follow-up decisions about the management of these crops.5.
? Key message
The optimal management of larch (Larix olgensis) plantations in Northeast China consisted of 2 or 3 thinnings and a rotation length of 55–61 years when economic profitability, wood production, and carbon sequestration were simultaneously maximized. Wood production ranged from 5.4 to 11.7 m3 ha?1 a?1, depending on site quality.? Context
L. olgensis is an important tree species in the northeast forest region of China, playing a significant role in the establishment of fast-growing and high-yielding plantation forests in China. However, the management of these plantations has not been optimized in previous studies.? Aims
The objective of the study was to find the optimal combinations of thinning times, thinning types, and rotation length for L. olgensis stands when both timber production and carbon stock are considered.? Methods
First, a growth and yield model was developed to simulate the dynamics of larch plantations. Then, the models were linked with the Hooke and Jeeves optimization algorithm to optimize forest management for two commonly used planting densities and three site qualities.? Results
Two thinnings were found to be suitable for larch plantations when the stand density at 10 years was 2125 trees/ha (corresponding to a planting density of 2500 trees/ha) whereas three thinnings were recommended when the density at 10 years was 2800 trees/ha (planting density of 3300 trees/ha). When the stand density was 2800 trees/ha, the optimal rotation length was 61, 58, and 55 years for site indices (SI) 12, 16, and 20 m (dominant height at 30 years), respectively. The mean annual wood production was 5.4 m3 ha?1 for SI 12, 8.2 m3 ha?1 for SI 16, and 11.7 m3 ha?1 for SI 20. The results were nearly the same for the lower initial stand density. The better the site quality of the stand, the earlier the thinnings were conducted.? Conclusion
In multifunctional forestry, optimal rotation lengths of larch plantations were 10–20 years longer than advised in the current silvicultural recommendations for Northeast China.6.
? Context
Physiological ecologists have been fascinated by height- or position-linked differences of leaf morphology within tall trees >25 m, but the exact cause is still debated, i.e., is it due to light or height-induced water stress?? Aims
The aim of this study was to demonstrate that relatively small trees (<15 m) have leaf morphologies that vary with height and that such variation depends on site-moisture variability.? Methods
Leaves were collected from Robinia pseudoacacia trees at two sites in China with contrasting moisture variability to gather baseline data on leaf morphology parameters.? Results
Most measured parameters changed regularly with height. Water potential linearly decreased with height. Leaf area and stomata area decreased with height, while leaf mass per area, carbon isotope composition (δ 13C), and stomata density increased with height. Mesophyll and epidermal cell width decreased with height, while leaf thickness and palisade cell length increased with height. All the morphology parameters between two sites were also significantly different.? Conclusions
Based on the field results, it is concluded that minor variations in water potential at the time of leaf growth influence leaf morphology at both site-level and height-level. Controlled environment experiments will be conducted to confirm this conclusion.7.
Ingrid Seynave Alain Bailly Philippe Balandier Jean-Daniel Bontemps Priscilla Cailly Thomas Cordonnier Christine Deleuze Jean-François Dhôte Christian Ginisty François Lebourgeois Dominique Merzeau Eric Paillassa Sandrine Perret Claudine Richter Céline Meredieu 《Annals of Forest Science》2018,75(2):48
Key message
The diversity of forest management systems and the contrasted competition level treatments applied make the experimental networks of the GIS Coop, a nationwide testing program in the field of emerging forestry topics within the framework of the ongoing global changes.Context
To understand the dynamics of forest management systems and build adapted growth models for new forestry practices, long-term experiment networks remain more crucial than ever.Aims
Two principles are at the basis of the experimental design of the networks of the Scientific Interest Group Cooperative for data on forest tree and stand growth (GIS Coop): contrasted and extreme silvicultural treatments in diverse pedoclimatic contexts.Methods
Various forest management systems are under study: regular and even-aged stands of Douglas fir, sessile and pedunculate oaks, Maritime and Laricio pines, mixed stands of sessile oak, European silver fir, and Douglas fir combined with other species. Highly contrasted stand density regimes, from open growth to self-thinning, are formalized quantitatively.Results
One hundred and eighty-five sites representing a total of 1206 plots have been set up in the last 20 years, where trees are measured regularly (every 3 to 10 years). The major outputs of these networks for research and management are the calibration/validation of growth and yield models and the drawing up of forest management guides.Conclusion
The GIS Coop adapts its networks so that they can contribute to develop growth models that explicitly integrate pedoclimatic factors and thus also contribute to research on the sustainability of ecosystems under environmental and socio-economic changes.8.
Key message
When areas of interest experience little change, remote sensing-based maps whose dates deviate from ground data can still substantially enhance precision. However, when change is substantial, deviations in dates reduce the utility of such maps for this purpose.Context
Remote sensing-based maps are well-established as means of increasing the precision of estimates of forest inventory parameters. The general practice is to use maps whose dates correspond closely to the dates of ground data. However, as national forest inventories move to continuous inventories, deviations between map and ground data dates increase.Aims
The aim was to assess the degree to which remote sensing-based maps can be used to increase the precision of estimates despite differences between map and ground data dates.Methods
For study areas in the USA and Norway, maps were constructed for each of two dates, and model-assisted regression estimators were used to estimate inventory parameters using ground data whose dates differed by as much as 11 years from the map dates.Results
For the Minnesota study area that had little change, 7-year differences in dates had little effect on the precision of estimates of proportion forest area. For the Norwegian study area that experienced considerable change, 11-year differences in dates had a detrimental effect on the precision of estimates of mean biomass per unit area.Conclusions
The effects of differences in map and ground data dates were less important than temporal change in the study area.9.
Jerzy Szwagrzyk Zbigniew Maciejewski Ewa Maciejewska Andrzej Tomski Anna Gazda 《Annals of Forest Science》2018,75(3):80
Key message
The disturbance of a research plot by a windstorm allowed us to study the role of the seedling bank in the regeneration processes. The released advance regeneration dominated among the saplings; taller individuals retained their position until the end of the study. Pioneer species occurred sporadically. Seven years after the disturbance, the windthrow was covered by a dense thicket of young trees.Context
The dominant role played by advance regeneration in natural regeneration processes after intense wind disturbances is still a matter of dispute.Aims
We took advantage of a windstorm in one of our research plots to study the role of the seedling bank released by the disturbance in the regeneration processes.Methods
We collected data in 70 plots, recording the survivorship of seedlings, annual height growth, and signs of browsing. The height ranking was analyzed with Kendall’s concordance coefficient, and the height growth rates were compared using Dunn’s test.Results
The density of seedlings increased from 6.7/m2 in 2008 to 8.1/m2 in 2010 and then decreased to 1.2/m2 in 2015. The density of saplings increased continuously from 0.14 to 1.9/m2. The highest size differentiation occurred in sycamore maple; the individuals which were taller before the windstorm retained their position until the year 2015. The only species that was recruited mainly from germinants was European hornbeam.Conclusion
The advance regeneration released by the windstorm played a major role in the regeneration process, while pioneer species occurred only sporadically. Seven years after the disturbance, the windthrow was already covered by a dense thicket of young trees.10.
Overview of methods and tools for evaluating future woody biomass availability in European countries
Susana Barreiro Mart-Jan Schelhaas Gerald Kändler Clara Antón-Fernández Antoine Colin Jean-Daniel Bontemps Iciar Alberdi Sonia Condés Marius Dumitru Angel Ferezliev Christoph Fischer Patrizia Gasparini Thomas Gschwantner Georg Kindermann Bjarki Kjartansson Pál Kovácsevics Milos Kucera Anders Lundström Gheorghe Marin Gintautas Mozgeris Thomas Nord-Larsen Tuula Packalen John Redmond Sandro Sacchelli Allan Sims Arnór Snorrason Nickola Stoyanov Esther Thürig Per-Erik Wikberg 《Annals of Forest Science》2016,73(4):823-837
11.
Florent Noulèkoun Asia Khamzina Jesse B. Naab John P. A. Lamers 《Annals of Forest Science》2017,74(4):78
Key message
The changes in the relative biomass allocation to roots in juvenile stands of fast-growing ( Leucaena leucocephala Lam., Moringa oleifera Lam., and Jatropha curcas L.) and slow-growing ( Anacardium occidentale L. and Parkia biglobosa Jacq.) afforestation species are driven mainly by ontogeny rather than resource availability. However, silvicultural management aiming at increasing availability of water and particularly nutrients enhances biomass production in all species.Context
Understanding the patterns of biomass allocation among tree species in response to ontogeny and to variation in resource availability is key to the successful restoration of degraded land using forest plantations.Aims
This study assessed the effects of resource availability and ontogeny on biomass accumulation and partitioning in five semi-arid afforestation species.Methods
The aboveground and belowground biomass production of fast-growing Leucaena leucocephala Lam., Moringa oleifera Lam., and Jatropha curcas L. and slow-growing Anacardium occidentale L. and Parkia biglobosa Jacq. was monitored following the application of manure (1 kg plant?1) and/or supplemental irrigation (0.5 L per sapling daily) during the first two rainy seasons and the intervening dry season on degraded cropland in Northern Benin.Results
Biomass accumulation in the fast-growing species was positively impacted by fertilization and irrigation during both rainy seasons. The slow-growing species responded positively to the silvicultural treatments during the dry and second rainy season. The application of fertilizer alone increased the biomass of P. biglobosa by up to 335% during the dry season. Fifteen months after planting, manure-treated L. leucocephala accumulated the most biomass (2.9 kg tree?1). The root fraction decreased with increasing tree size in all species. The comparison of root versus shoot allocation in trees of equal size indicated that the treatment-induced shifts in biomass partitioning were controlled by ontogeny, which explained 86–95% of the variation in root-shoot biomass relationships.Conclusion
While ontogeny was the main driver of biomass partitioning, increased resource availability induced a larger production of biomass, overall leading to greater aboveground production in all species.12.
Caterina Palombo Patrick Fonti Bruno Lasserre Paolo Cherubini Marco Marchetti Roberto Tognetti 《Annals of Forest Science》2018,75(4):93
Key message
Comparisons between compression and opposite wood formation in prostrating Pinus mugo indicate that the secondary meristem can produce more tracheids with thicker walls by also increasing the number of contemporaneously differentiating cells, rather than only increasing the duration or the rate of cell formation.Context
Although cambium tissues within a stem experience the same climatic conditions, the resulting wood structure and properties can strongly differ. Assessing how meristem differently regulates wood formation to achieve different anatomical properties can help understanding the mechanisms of response and their plasticity.Aims
We monitored the formation of compression (CW) and opposite (OW) wood within the same stems to understand whether achieved differences in wood structure are caused by modifications in the process of cell formation.Methods
We collected weekly microcores of compression and opposite wood from the curved stem of ten treeline prostrating mountain pines (Pinus mugo Turra ssp. mugo) at the Majella massif in Central Italy.Results
Results indicate that cambium formed approximately 1.5 times more cells in CW than OW, despite that CW cell differentiation only extended 2 weeks longer and the residence time of CW cells in the wall-thickening phase was only 20% longer. Differences in their formation were thus mainly related to both the rates and the width of the enlarging and wall-thickening zones (i.e., the number of cells simultaneously under differentiation) and less to duration of cell formation.Conclusion
We conclude that to achieve such a different wood structures, the efficiency of the secondary meristem, in addition of altered rate of cell division and differentiation, can also modify the width of the developing zones. Thus, deciphering what rules this width is important to link environmental conditions with productivity.13.
Damien Bonal Mathilde Pau Maude Toigo André Granier Thomas Perot 《Annals of Forest Science》2017,74(4):72
Key message
Mixing sessile oak and Scots pine in central France to reduce intraspecific competition for water resources did not improve the ability of these two species to withstand severe drought during the summer.Context
In order to reduce the impact of increasingly extreme droughts on forests, managers must adapt their practices to future climate conditions. Maintaining a greater diversity of tree species in temperate forest ecosystems is one of the recommended options.Aims
We addressed how interactions between sessile oak and Scots pine in mixed forests in central France affect their functional response to drought.Methods
We characterized the carbon isotope composition (δ13C) in the tree growth rings formed during wet (2001, 2007) or dry (2003, 2004) summers for each of the two species growing both in pure and in mixed stands in order to compare the effect of stand composition on variations in carbon isotope discrimination (Δ13C) among contrasted years.Results
The severe drought in 2003 induced a strong decrease in Δ13C for all trees and in all stands as compared to 2001. This decrease was greater in pine than in oak. There was no significant difference between pure and mixed stands in the response of either species to drought.Conclusion
Mixing sessile oak and Scots pine in stands in central France does not improve the ability of either species to withstand severe drought during the summer.14.
Angelo Rita Francesco Ripullone Tiziana Gentilesca Luigi Todaro Antonio Saracino Marco Borghetti 《Annals of Forest Science》2017,74(3):49
Key message
Apical dominance ratio (ADR), reported as a suitable indicator for the growth and development of Abies alba , is concurrently determined by morphological and functional plant traits. Structural equation modeling (SEM) proved here to be an effective multivariate technique to represent the contribution of different variables in explaining ADR variability.Context
During the natural recruitment of understory tree saplings, the light environment and competition among individuals may change drastically as well as their growth patterns. To cope with this, saplings have a remarkable ability to accordingly modify their physiology and morphology. Therefore, understanding the ecological significance of plant structural patterns requires an integrated view of morphological, architectural, and physiological attributes of plants.Aims
Here, we applied a SEM approach to understand the mechanisms influencing the ADR, recently reported as suitable indicator of the growth conditions favoring silver fir (Abies alba Mill.) natural regeneration in Mediterranean areas.Methods
A series of plant traits (e.g., root-collar diameter, leaf mass per area, and isotope composition) were combined into two main latent variables, namely Morphology and Physiology, to account for their relative contribution in explaining the ADR variability.? Results
Our results underline the importance of variables accounting for the photosynthetic capacity and leaf economics in determining ADR; among them, leaf mass per area (LMA) emerged as an important driving variable.? Conclusion
SEM proved to be an effective multivariate technique to represent the coordination of different morphological and functional variables in explaining ADR variability in silver fir.15.
Elisabeth Wallin Daniel Gräns Douglass F. Jacobs Anders Lindström Nathalie Verhoef 《Annals of Forest Science》2017,74(3):59
Key Message
Gene expression analysis showed that prolonged short day (SD) treatment deepened dormancy and stimulated development of freezing tolerance of Picea abies seedlings. Prolonged SD treatment also caused later appearance of visible buds in autumn, reduced risks for reflushing, and promoted earlier spring bud break.Context
Short day (SD) treatment of seedlings is a common practice in boreal forest tree nurseries to regulate shoot growth and prepare the seedlings for autumn planting or frozen storage.Aims
The aim of this study was to examine responses of Norway spruce (Picea abies (L.) Karst.) to a range of SD treatments of different length and evaluate gene expression related to dormancy induction and development of freezing tolerance.Methods
The seedlings were SD treated for 11 h a day during 7, 14, 21, or 28 days. Molecular tests were performed, and the expression profiles of dormancy and freezing tolerance-related genes were analyzed as well as determination of shoot growth, bud set, bud size, reflushing, dry matter content, and timing of spring bud break.Results
The 7-day SD treatment was as effective as longer SD treatments in terminating apical shoot growth. However, short (7 days) SD treatment resulted in later activation of dormancy-related genes and of genes related to freezing tolerance compared to the longer treatments which had an impact on seedling phenology.Conclusion
Gene expression analysis indicated an effective stimulus of dormancy-related genes when the SD treatment is prolonged for at least 1–2 weeks after shoot elongation has terminated and that seedlings thereafter are exposed to ambient outdoor climate conditions.16.
Udo Mantau Thomas Gschwantner Alessandro Paletto Marian L. Mayr Christian Blanke Evgeniya Strukova Admir Avdagic Paolo Camin Alain Thivolle-Cazat Przemko Döring Edmundas Petrauskas Hermann Englert Klemens Schadauer Susana Barreiro Adrian Lanz Claude Vidal 《Annals of Forest Science》2016,73(4):885-894
Key message The application of the ITOC model allows the estimation of available biomass potentials from forests on the basis of National Forest Inventory data. The adaptation of the model to country-specific situations gives the possibility to further enhance the model calculations.
Context
With the rising demand for energy from renewable sources, up-to-date information about the available amount of biomass on a sustainable basis coming from forests became of interest to a wide group of stakeholders. The complexity of answering the question about amounts of biomass potentials from forests thereby increases from the regional to the European level.Aims
The described ITOC model aims at providing a tool to develop a comparable data basis for the actual biomass potentials for consumption.Methods
The ITOC model uses a harmonized net annual increment from the National Forest Inventories as a default value for the potential harvestable volume of timber. The model then calculates the total theoretical potential of biomass resources from forests. By accounting for harvesting restrictions and losses, the theoretical potential of biomass resources from forests is reduced and the actual biomass potentials for consumption estimated.Results
The results from ITOC model calculations account for the difference between the amounts of wood measured in the forests and the actual biomass potentials which might be available for consumption under the model assumptions.Conclusion
The gap between forest resource assessments and biomass potentials which are available for consumption can be addressed by using the ITOC model calculation results.17.
Bogdan Brzeziecki Kamil Bielak Leszek Bolibok Stanisław Drozdowski Jacek Zajączkowski Henryk Żybura 《Annals of Forest Science》2018,75(3):89
? Key message
Long-term strict protection of woodland communities may lead to their compositional simplification and homogenisation.? Context
In the past, it has often been postulated that structures and processes typical for natural forests should be mimicked by silvicultural activities in the case of managed tree stands.? Aims
To determine which features and traits of natural woodland communities (alongside typical old-growth attributes) should be imitated in managed forests, as well as which should not (and for what reasons).? Methods
Tree data from five permanent study plots (of a total area of 15.44 ha) established in 1936 in the core area of the Bia?owie?a National Park (NE Poland) are used to calculate several quantitative indices describing the temporal dynamics (in terms of stand structure and composition) of eight major woodland community types.? Results
Most structural attributes revealed rather high stability over time. In contrast to these, during the observation period, noticeable changes in the composition of particular Bia?owie?a woodland communities have been taking place, related to declining occurrence and reduced roles characteristic for a large number of tree species.? Conclusion
In many ways, natural forests can serve as an important model for managed forest stands. However, in certain circumstances, silvicultural treatments counteracting natural developmental trends may appear to be indispensable, especially when more diverse and stable tree species composition (at a given spatial and temporal scale) is indicated or desirable.18.
Xiaolu Tang Lutz Fehrmann Fengying Guan David I. Forrester Rubén Guisasola César Pérez-Cruzado Torsten Vor Yuanchang Lu Juan Gabriel Álvarez-González Christoph Kleinn 《Annals of Forest Science》2017,74(1):12
Key message
A generalized algebraic difference approach (GADA) developed in this study improved the estimation of aboveground biomass dynamics of Cunninghamia lanceolata (Lamb.) Hook and Castanopsis sclerophylla (Lindl.) Schott forests. This could significantly improve the fieldwork efficiency for dynamic biomass estimation without repeated measurements.Context
The estimation of biomass growth dynamics and stocks is a fundamental requirement for evaluating both the capability and potential of forest carbon sequestration. However, the biomass dynamics of Cunninghamia lanceolata and Castanopsis sclerophylla using the generalized algebraic difference approach (GADA) model has not been made to date.Aims
This study aimed to quantify aboveground biomass (AGB, including stem, branch and leaf biomass) dynamics and AGB increment in C. lanceolata and C. sclerophylla forests by combining a GADA for diameter prediction with allometric biomass models.Methods
A total of 12 plots for a C. lanceolata plantation and 11 plots for a C. sclerophylla forest were selected randomly from a 100 m × 100 m systematic grid placed over the study area. GADA model was developed based on tree ring data for each stand.Results
GADA models performed well for diameter prediction and successfully predicted AGB dynamics for both stands. The mean AGB of the C. lanceolata stand ranged from 69.4 ± 7.7 Mg ha?1 in 2010 to 102.5 ± 11.4 Mg ha?1 in 2013, compared to 136.9 ± 7.0 Mg ha?1 in 2010 to 154.8 ± 8.0 Mg ha?1 in 2013 for C. sclerophylla. The stem was the main component of AGB stocks and production. Significantly higher production efficiency (stem production/leaf area index) and AGB increment was observed for C. lancolata compared to C. sclerophylla.Conclusion
Dynamic GADA models could overcome the limitations posed by within-stand competition and limited biometric data, can be applied to study AGB dynamics and AGB increment, and contribute to improving our understanding of net primary production and carbon sequestration dynamics in forest ecosystems.19.
Matthew G. Hamilton Jules S. Freeman David P. Blackburn Geoffrey M. Downes David J. Pilbeam Brad M Potts 《Annals of Forest Science》2017,74(1):17
Key message
Multiple lines of evidence suggest acoustic wave velocity (AWV) would provide a rapid and efficient method to indirectly select for superior pulp yield in Eucalyptus globulus breeding programs.Context
Eucalyptus globulus is one of the most widely planted hardwood species in temperate regions of the world and is primarily grown for pulpwood.Aims
To determine if acoustic wave velocity (AWV) can be used to indirectly select for kraft pulp yield in E. globulus.Methods
Genetic group effects, additive and non-additive variance components, and genetic correlations were estimated for AWV and pulpwood traits, including Kraft pulp yield. In a separate trial, the relative position of quantitative trait loci (QTL) for these traits was compared.Results
Estimated narrow-sense heritabilities for AWV and pulp yield were both 0.26, and these traits were strongly genetically correlated (0.84). Furthermore, co-located QTL for these traits were identified. Further evidence that AWV could be used to indirectly select for pulp yield was provided by the ranking of genetic groups—Otways and King Island had the highest AWV and pulp yield and Strzelecki and Tasmania the lowest. There was no evidence of dominance variation in wood property traits.Conclusion
Together, these findings suggest that AWV could be used as a selection criterion for kraft pulp yield in E. globulus breeding programs.20.
Marc Soler Martin José Antonio Bonet Juan Martínez De Aragón Jordi Voltas Lluís Coll Víctor Resco De Dios 《Annals of Forest Science》2017,74(3):51