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A Flexible Hybrid Model of Life Cycle Carbon Balance for Loblolly Pine (Pinus taeda L.) Management Systems  [PDF]
Carlos A. Gonzalez-Benecke,Timothy A. Martin,Eric J. Jokela,Rafael De La Torre
Forests , 2011, DOI: 10.3390/f2030749
Abstract: In this study we analyzed the effects of silvicultural treatments on carbon (C) budgets in Pinus taeda L. (loblolly pine) plantations in the southeastern United States. We developed a hybrid model that integrated a widely used growth and yield model for loblolly pine with published allometric and biometric equations to simulate in situ C pools. The model used current values of forest product conversion efficiencies and forest product decay rates to calculate ex situ C pools. Using the model to evaluate the effects of silvicultural management systems on C sequestration over a 200 year simulation period, we concluded that site productivity (site quality), which can be altered by silviculture and genetic improvement, was the major factor controlling stand C density. On low productivity sites, average net C stocks were about 35% lower than in stands with the default average site quality; in contrast, on high quality sites, C stocks were about 38% greater than average productivity stands. If woody products were incorporated into the accounting, thinning was C positive because of the larger positive effects on ex situ C storage, rather than smaller reductions on in situ C storage. The use of biological rotation age (18 years) was not suitable for C sequestration, and extended rotation ages were found to increase stand C stock density. Stands with an 18-year-rotation length had 7% lower net C density than stands with a 22-year-rotation length; stands with a 35-year-rotation length had only 4% more C than stands harvested at age 22 years. The C sequestered in woody products was an important pool of C storage, accounting for ~34% of the average net C stock. Changes in decomposition rate, associated with possible environmental changes resulting from global climate change, affected C storage capacity of the forest. When decay rate was reduced to 10% or increased to 20%, the C stock in the dead pool (forest floor and coarse woody debris) was reduced about 11.8 MgC?ha ?1 or increased about 13.3 MgC?ha ?1, respectively, compared to the average decay rate of 15%. The C emissions due to silvicultural and harvest activities were small (~1.6% of the gross C stock) compared to the magnitude of total stand C stock. The C model, based on empirical and biological relationships, appears appropriate for use in regional C stock assessments for loblolly pine plantation ecosystems in the southern U.S.
Effect of Thinning and Harvest Type on Storage and Losses of Phosphorous in Pinus taeda L. Plantations in Subtropical Argentina  [PDF]
Rodolfo Andrés Martiarena,Jorge Luis Frangi,Martín Alcides Pinazo,Alejandra Von Wallis,Roberto Antonio Fernández
International Journal of Forestry Research , 2011, DOI: 10.1155/2011/761532
Abstract: The aim of this study was to evaluate the effect of thinning intensity and different harvest types on ecosystem P conservation in 20-year-old Pinus taeda plantation ecosystems at Misiones province, Argentina. The plantation was established in 1985, thinned at three intensities—0, 33, and 66% of basal area of control plots removed by thinning—and harvested in 2005. The nutrient content at harvest was determined for tree, shrub, and herb layers, the forest floor and upper mineral soil. Two harvest types were simulated: stem only and whole tree. Total P content was 56.8, 46.8, and 38.6?kg· ha?1 for 0, 33, and 66% thinning, respectively. Total P exported by harvest was different among treatments, the highest at 0% thinning treatment. Phosphorus stability index values indicated that the P most conservative management option is 66% thinning, harvest of stem only and retention of forest floor, understory, and harvest residues. 1. Introduction Pinus taeda L. (loblolly pine) is the most widely planted tree species in Argentina [1]. Misiones, with a subtropical humid climate, is the province having the largest planted area with 300,000?ha [2]. Plantations are established mostly on deep red soils of the order Ultisols [3] where the main fertility problems are associated with low availability of P and K [4, 5]. Thinning reduces stand density favoring dominant trees and those with better form, increases the growth rate of retained trees, and results in stands with uniform tree diameters. These are important features in managing fast-growing plantations [6] and providing the increase of the remnant stand basal area to obtain more volume of quality wood at the end of the rotation [7, 8]. Thinning also influences ecosystem development [9], including modifying the availability and use of light, nutrients, and water for trees [10] and also affecting the understory [11]. Despite the fact that the understory represents a small fraction of total biomass, dependent on plantation basal area [12], it may act as an important nutrient repository in the plantation ecosystem [13]. This is supported by observations which show differences in ecosystem nutrient content between unthinned and thinned plots [14] at the end of a rotation. Intensively thinned plots have higher sun energy inputs to forest floor, modifying site conditions for decomposers and speeding up decomposition [15–21]. The result is a reduction of organic matter accumulated on the forest floor. Harvesting causes the greatest nutrient losses [22] and can change the C balance [23] including changes in decomposition
Pine Growth and Nutrient Status as Related to Pine/Alder Ratio in Mixed Stands  [PDF]
Miguel A. Lopez-Lopez,R.M. Reich,C. Aguirre-Bravo,A. Velazquez-Martinez
Journal of Biological Sciences , 2009,
Abstract: The relationships between varying pine/alder ratios and pine growth and nutrient status were experimentally examined in three Regeneration Areas (RA) in the Mexican State of Hidalgo. A randomized complete block design with five pine/alder ratios as pseudo-treatments was established at each of the RAs. Pine density, which varied among plots, was blocked to control its effects on pine growth. The results indicate that the effects of alder on pine growth largely depend on pine density, which affects light availability to alders. Growth variables showed saturation curves with respect to increasing alder densities in the 1987 and 1994 RAs. Pine growth was maximum for pine/alder ratios of 2666/20 and 711/267 in the 1987 and 1994 RAs, respectively. For the 1989 RA, maximum pine growth was not reached since alder densities were low. When alders were in the understory, light limitations probably impaired N-fixation, bringing about competition effects for N between alder clumps and pine trees. Management techniques that promote sunlight reduction to alders may switch alder function from beneficial to detrimental. When alder was fully exposed to sunlight, it gave up all N required by pines. Availability of P and K to pine trees was increased by alders exposed to full sunlight. When sunlight limited alder performance, P and K concentrated within pine needles due to reductions in pine growth resulting from N deficiency.
SB-CORSICA: A Program to Support the Management of Corsican Pine Stands
Barreto,Luís Soares;
Silva Lusitana , 2004,
Abstract: this paper introduces program sb-corsica, for the supporting of the forestry of even-aged and uneven-aged stands of corsican pine (pinus nigra ssp. laricio ). the program, that applies the theoretical findings of the author, is written in basic, and it has two subprograms: a) simulator sb-corso; b) subprogram sb-corsicana. the structure of the text reflects the structure of the program. in the first part, the author accomplishes the following: a) establishes the allometric equations for the biomasses of the tree components; b) he characterises the architecture of the tree; c) he proposes gompertz equations for the biomasses of the components of the tree and of the self-thinned even-aged pure stands; d) he presents simulator sb-corso. the simulator, for the same stands of corsican pine establishes the yield table, the biomasses table and the table of the weights of n, p, k, ca, mg retained in the biomasses. in the second part of the paper, the author presents subprogram sb-corsicana. knowing the structure of a self-thinned even-aged pure stand of corsican pine, at a given age, for its symmetric uneven-aged stand, the program establishes (a) the stand structure (age and dbh classes, frequencies, standing volume, area per tree), and (b) nine alternative management guidelines.
Resin production in natural Aleppo pine stands in northern Evia, Greece  [PDF]
K. Spanos,D. Gaitanis,I. Spanos
Web Ecology (WE) , 2010, DOI: 10.5194/we-10-38-2010
Abstract: We investigated the variability in resin yield of Aleppo pines in Evia (Greece) with the aim to exploit this natural resource in a sustainable way. Ten experimental plots were established in natural pine stands for monitoring. Our results revealed significant differences among stands, with high variation among individual trees in each plot. Maximum resin production was achieved in the Livadakia site whereas the minimum was obtained in Kokinomilia. All trees were classified according to their resin production into five classes ranging from not economically profitable (I) to highly profitable (V). From a total of 2483 trees, 1043 (42%) were in class I whereas the remaining 58% was classified into economically acceptable classes (II–V). A weak correlation (R2 = 0.315) between resin production and tree size was found suggesting that taller trees produced more resin than smaller trees.
Large outbreaks of Ips acuminatus in Scots pine stands of the Italian Alps
Faccoli M,Colombari F,Dal Pont C,Finozzi V
Forest@ , 2010, DOI: 10.3832/efor0644-007
Abstract: In the last years, many Scots pine (Pinus sylvestris) stands have been severely attacked by the bark beetle Ips acuminatus (Coleoptera Curculionidae Scolytinae). In the outbreak area of San Vito di Cadore (Eastern Dolomites), the number of attacked trees since 2005 and both the emergence of bark beetles and natural enemies have been assessed. The investigated forests showed dozens of easily recognizable infestation spots with size ranging from about 20-30 trees (small spots) up to 300 trees (large spots). These infested spots evolved quickly, while new ones appeared within a radius of few hundreds of meters. During the last 5 years (2006-2010) we sampled branches from small and large spots and lodged them into emergence cages: adults of I. acuminatus as well as natural enemies were collected weekly, identified and counted. At the same time, a monitoring program of the surveyed pine stands was carried out to check the enlargement of old spots and the appearance of new ones. Voltinism and phenology of I. acuminatus were investigated by pheromone traps baited with different lures (Austrian vs. Spanish lures). The effects of a sanitation felling of about 4500 infested trees, carried out by the Regional Forest Service in autumn 2007 on I. acuminatus population were also assessed. Throughout the whole sampling area I. acuminatus resulted bivoltine, with the highest density attained during the first generation. However, a part of the population still evidenced a monovoltine behaviour. The realized sanitation felling strongly reduced both breeding sites and the number of infested trees observed during the following year. Moreover the pheromone-baited traps gave useful information about changes in bark beetle population density; the trapping efficiency of Spanish lure resulted clearly higher than the Austrian one. Finally, the recorded parasitism may have a role in outbreak dynamics as it was significantly higher during the second host generation, in both small and large spots.
Flammability and Combustibility of Aleppo Pine (Pinus halepensis Mill.) Stands  [PDF]
?eljko ?panjol,Roman Rosavec,Damir Bar?i?,Ivo Gali?
Croatian Journal of Forest Engineering , 2011,
Abstract: In terms of its biodiversity, the Mediterranean area is one of the most important regions in the world. In recent years this area has often been affected by forest fires. Forest fires are the most important and most powerful environmental factor causing changes (Trabaud 1991, Casal 1985, 1993 Calvo, Le Houerou 1993, Pyne et al. 1996, Naveh, 1999). When talking about the occurrence and spread of forest fires, vegetation characteristics, fuel supplies and climate factors (mean atmospheric conditions) are the most decisive and important factors of natural origin (Rosavec 2010). Fuel is any substance or mixture of substances that can be ignited and burn. Forest fuels mostly come frompine culture, especially when speaking of younger stands. As we cannot have a direct impact on climate, geology, soil and relief factors, our efforts should be focused on potential availability of forest fuels and vegetation where we can prevent the occurrence and spread of wildfires. Accordingly, and with favorable climatic conditions for starting forest fire, fire risk can be reduced to aminimum if caremeasures are taken regulating the amount of the potential of forest fuels. Therefore, timely and according to professional standards of care measures derived stands and culture greatly influenced the reduction in the number and size of fire burn area. Testing of ignition delay, i.e. the time required to ignite the sample, and burning duration, or time elapsed from the moment of ignition to self-quenching of the sample, and determination of moisture content of dead (discarded needles) and living (green needles) fuel was carried out in the period from June 2007 to June 2009 at the educational center NP O Rab, Faculty of Forestry, University of Zagreb, in a 40-year stand of Aleppo pine (Pinus halepensis Mill.). Themethodology prescribed byValette (1990) was used to test the ignition delay and burning of the living fuel. Themoisture content of tested samples of living and dead fuels were obtained using a standard equation for determining the moisture content (percentage of dry weight), the drying method. Investigations were conducted on the island. It is located in the Kvarner group of islands, and along with several surrounding islands, islets and reefs makes the Rab archipelago. In the structure of the Island of Rab, Upper Paleogene Quaternary sediments are present but they are much less developed, while chalk and Paleogene sediments largely prevail. Walter climate diagram (Walter 1955) was used to view the annual variation of air temperature and precipitationwas used. He, among ot
Predicting the above-ground biomass of calabrian pine (Pinus brutia Ten.) stands in Turkey
A Durkaya, B Durkaya, A ünsal
African Journal of Biotechnology , 2009,
Abstract: Biomass equations are presented for calabrian pine stands within the Adana-Karaisaly Regional Forestry Management Area. Thirty three sample plots, each of 0.04 ha, were chosen in order to define the biomass equations of calabrian pine, the most common needle leave species in Turkey. A tree which is the most similar to mean tree according to basal area was cut in each sample area as a sample tree. Various models were tested, utilizing the diameter (d) and the height (h) as independent variables and the most suitable models were determined. Using these models, above-ground biomass amounts can easily be acquired for single trees and stands.
Allometric relationships for volume and biomass for stone pine (Pinus pinea L.) in Italian coastal stands
Cutini A,Chianucci F,Manetti Maria Chiara
iForest : Biogeosciences and Forestry , 2013, DOI: 10.3832/ifor0941-006
Abstract: Tree biomass plays a key role in sustainable forest management and in determining forest carbon stocks. Accurate estimates based on species-specific empirical data are necessary for regional and national inventories and forest carbon management. In this study, we obtained allometric relationships for volume and aboveground biomass for stone pine (Pinus pinea) based on empirical data collected in four coastal stands in Italy. Root sampling was also performed. The results enabled generalized equations for volume and aboveground biomass to be developed. However, an analysis also showed several differences in biomass allocation in stone pine resulting from different stand characteristics, emphasizing the importance of stand-dependent factors for adjusting regional or national biomass calculations. Biomass expansion factors were also provided. This study provides tools to help forest managers in quantifying volume and biomass, thereby contributing to the accurate estimation of carbon sequestration and stocks in stone pine stands in Italy.
Alteration in Vital State Parameters of Scots Pine Tree-Stands under Technogenic Pollution  [PDF]
Tatiana A. Mikhailova,Olga V. Kalugina,Olga V. Shergina,Ekaterina N. Taranenko
International Journal of Environment , 2014, DOI: 10.3126/ije.v3i4.11729
Abstract: The study was focused on the relation between deterioration of vital state parameters of Scots pine (Pinus sylvestris L.) tree-stands polluted by various technogenic sources, and the level of polluting agents accumulation in the needles. Changes in the balance of the most important biogenic elements and their proportion in the needles of polluted trees have been shown. The results confirm systemic character of polluting agents impact on tree-stands vital state. It may be presumed to show in the following order: polluting agents accumulation in assimilating organs → disbalance of elements composition of plant organism → disturbance of plant organism nutritious conditions → disturbance of tree growth characteristics → reduction of tree-stands productivity.
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