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1.
The main purpose of the present investigation is to examine and compare three methods for diameter distribution modeling in
terms of their fitness to predict from stand level variables the diameter distributions of even-aged Austrian black pine (Pinus nigra Arn.) plantations in Bulgaria. The percentile-based projection method involving empirical probability density function based
on 12 percentiles was the first method tested. A new modified approach based on the first method was proposed as the second
alternative. The third method was the 2-parameter Weibull functional model in which parameters were recovered from the first
and the second raw moments and the second central moment of the empirical distributions. The Kolmogorov–Smirnov test was applied
to compare the experimental distributions with the predicted ones, and estimation of the error indices was employed to evaluate
the total absolute deviation of the predicted numbers from the actual ones by diameter class. The two-parameter Weibull function
proved superior to the examined alternative percentile-based projection methods and the newly proposed percentile method,
without a driver percentile showed improved precision compared to the classical percentile method (with a driver percentile).
The parameters of the Weibull frequency distribution function can be easily recovered from the stand quadratic mean diameter.
Consequently, this diameter distribution model could be incorporated as a sub-model for stand horizontal structure characterization
within the Stand Density Management Diagram modeling framework. 相似文献
2.
应用Weibull函数来拟合油松(Pinus tabulaeformis)、侧柏(Platycladus orientalis)人工林树冠率的分布,研究发现林分平均树冠率与相对林分密度指数之间呈极显著线性关系,并随林分相对密度指数增加而降低;Weibull函数参数b与油松、侧柏人工林林分平均树冠率呈极显著线性关系,参数c与侧柏林分平均树冠率呈二次方关系,在油松林分中则为一常数值;通过对未参加建模的油松、侧柏样地进行动态预测,发现Weibull函数对林分树冠率分布预测值与实测值之间没有显著性差异。因此,该方法可以应用于预测油松和侧柏人工林树冠率的动态分布。 相似文献
3.
Marc Palahí Timo Pukkala Elena Blasco Antoni Trasobares 《European Journal of Forest Research》2007,126(4):563-571
The purpose of this study was to compare the beta, Johnson SB, Weibull and truncated Weibull functions in describing the diameter
distributions of forest stands in Catalonia. The data consisted of permanent sample plots from the Spanish National Forest
Inventory in Catalonia. The empirical data represent left-truncated distributions, as the smallest diameter measured in the
field was 7.5 cm. A total of 1,242 plots were used to fit the functions and analyze their performance. The distribution functions
were fitted to the diameter distributions of the number of stems (DDN) and stand basal area (DDG). The performance of the candidate functions was compared by means of their bias and RMSE for different diameter sums measuring
the difference between the empirical and fitted distributions. The leftmost part (from 0 to 7.5 cm) of the non-truncated functions
was ignored in this analysis. Sensitivity analyses were conducted to check whether the results depended on the number of trees
measured in the stand, or the main species of the stand. The truncated Weibull function for the diameter distribution of stand
basal area appeared to be in all cases the most accurate and consistent function. Generally, functions describing the distribution
of stand basal area performed better than functions that described the distribution of the number of trees. Of the basal area
distributions, beta and Johnson’s SB were the second best and nearly equally good with each other. The order of precision
of the tested functions was: truncated Weibull for DDG, truncated Weibull for DDN, Johnson’s SB for DDG, beta for DDG, beta for DDN and Weibull for DDG, Weibull for DDN, and Johnson’s SB for DDN. 相似文献
4.
Dario Martin-Benito Hans Beeckman Isabel Cañellas 《European Journal of Forest Research》2013,132(1):33-45
We investigated the influence of climate on the ring width and xylem anatomy of two co-occurring pines (Pinus nigra Arn. and P. sylvestris L.) in the mountains of east-central Spain in order to test their utility for dendroclimatic reconstructions. We developed chronologies of ring width, mean lumen diameter and mean cell-wall thickness (in the earlywood, latewood, and the total annual ring) and the number of cells between 1960 and 2006. Drought, expressed as the standardized precipitation-evapotranspiration index (SPEI), was the main climatic driver of tree radial growth, although trees were also sensitive to temperature (negative effect in previous autumn and current summer) and precipitation (with a general positive effect). P. sylvestris response was stronger to climate of the current year, whereas the effect of previous-year climate was more important for P. nigra. Warm and dry summers reduced ring width, tracheid lumen, and wall thickness in both species, whereas warm winter-spring temperatures had the opposite effect, primarily for P. sylvestris. Previous-year or early-season conditions mainly affected earlywood features, whereas latewood was more responsive to summer climate. Overall, climate appeared to be a stronger limiting factor for P. sylvestris. During periods of drought, cell-wall thickness was reduced while lumen width increased in the latewood of P. sylvestris. This could compromise its hydraulic safety against drought-induced cavitation as our site was close to the southern and dry edge of the species distribution area. Our results suggest that anatomical variables record different and stronger climate information than ring width variables, especially in P. sylvestris. Reconstruction models for SPEI at the 3-month scale were developed for July–August and September–October using principal components regression. The best models included anatomical and width variables of both pine species suggesting that tracheid chronologies can be useful for drought reconstructions especially at mesic sites or with species that encode a mixed drought and temperature-precipitation signal. 相似文献
5.
The purpose of this study was to construct models for predicting the structure of young Scots pine (Pinus sylvestris L.) stands. The two-parameter Weibull function characterized the height distribution of the stands. In young stands height was preferred to dbh as a random variable because of its continuous feature. Tree diameters were predicted using a multiplicative model, fitted as a linearized mixed-effect model. The modelling data consisted of repeatedly measured Scots pine dominated juvenile stands, carried out on a sub-sample of the 7th National Forest Inventory. The data covered a dominant height range from 0.2 up to 17 m. Two independent data sets were used to validate the models. The Weibull function was fitted using the maximum likelihood method. Four methods for predicting the distributions were compared: (1) parameter prediction models (PPM) consisting of seemingly unrelated regression equations, (2) a generalized linear model (GLM) which was a one-stage distribution and model fitting procedure, (3) a hybrid method including PPM for the shape parameter together with moment-based parameter recovery for the scale parameter, and (4) inclusion of moment-based parameter recovery for the scale parameter in the estimated GLM. Goodness-of-fit were tested in terms of Kolmogorov–Smirnov and error index statistics. Parameter recovery showed no improvement when used with PPM, but it improved GLM and gave the overall best performance for this new method. The constructed diameter–height model showed quite flexible and unbiased behaviour. Models are recommended as practical tools for Finnish forest management planning purposes. 相似文献
6.
Two-year-old Picea sitchensis (Queen Charlotte Islands and Oregonprovenances), Pseudotsuga menziesii, Larix kaempferi, Larixeurolepis, Pinus sylvestris and Pinus nigra var. maritima werelifted at intervals during two winters and planted within 24h on a nearby second rotation site. Physiological conditionat planting, measured by root growth potential and fine rootelectrolyte leakage, and outplanting performance were significantlyinfluenced by lifting date. There were consistent differencesin the species' response to lifting date. Planting out in Septemberresulted in poor survival. Survival of P. sitchensis liftedin October until April was >90 per cent. Pinus sylvestrisand P. nigra had survivals of >90 per cent when lifted inNovember and January respectively until March. There was noclear pattern in P. menziesii performance. Both L. kaempferiand L. eurolepis had two periods of good survival—Octoberand March—with significantly poorer survival and growthassociated with mid-winter planting. The double peak in larchperformance was closely related to root growth potential; lowmid-winter establishment was associated with root growth potentialsof <5 even though the nursery root systems were in excellentcondition as assessed by electrolyte leakage. 相似文献
7.
Pinus nigra Arnold var. pallasiana Endl. and Abies equi-trojaniAschers-Sinten are indigenous species of Turkey. The area ofPinus nigra is very large (more than 2 million hectares) occurringin the west, south and north of Turkey. However, Abies equi-trojanioccurs only in the west of Turkey in the Ida Mountains (Kazdagi)and is of limited area (5500 ha).These two species naturallyform both mixed stands and pure stands in the Ida Mountains. When mixed stands of Pinus nigra and Abies equi-trojani areregenerated, if the seedlings of these two species regeneratesimultaneously, the Pinus nigra will be eliminated from thestand in 15 to 25 years because of the rapid growth of Abiesequi-trojani. In different site conditions, Abies equi-trojanireaches 22–30 m in height and 40–65 cm in diameterin 70 years, whereas Pinus nigra reaches 17–22 m in heightand 25–40cm in diameter in the same period in the sameforest sites. 相似文献
8.
Pau Brunet-Navarro Frank J. Sterck Jordi Vayreda Jordi Martinez-Vilalta Godefridus M.J. Mohren 《Annals of Forest Science》2016,73(4):1025-1034
Key message
Self-thinning lines are species- and climate-specific, and they should be used when assessing the capacity of different forest stands to increase biomass/carbon storage.Context
The capacity of forests to store carbon can help to mitigate the effects of atmospheric CO2 rise and climate change. The self-thinning relationship (average size measure ～ stand density) has been used to identify the potential capacity of biomass storage at a given density and to evaluate the effect of stand management on stored carbon. Here, a study that shows how the self-thinning line varies with species and climate is presented.Aims
Our main objective is thus testing whether species identity and climate affect the self-thinning line and therefore the potential amount of carbon stored in living biomass.Methods
The Ecological and Forest Inventory of Catalonia was used to calculate the self-thinning lines of four common coniferous species in Catalonia, NE Iberian Peninsula (Pinus halepensis, Pinus nigra, Pinus sylvestris and Pinus uncinata). Quadratic mean diameter at breast height was chosen as the average size measure. The self-thinning lines were used to predict the potential diameter at a given density and study the effect of environmental variability.Results
Species-specific self-thinning lines were obtained. The self-thinning exponent was consistent with the predicted values of ?3/2 and ?4/3 for mass-based scaling for all species except P. sylvestris. Species identity and climatic variability within species affected self-thinning line parameters.Conclusion
Self-thinning lines are species-specific and are affected by climatic conditions. These relationships can be used to refine predictions of the capacity of different forest stands to increase biomass/carbon storage.9.
火炬松人工林直径分布收获模型的研究 总被引：1，自引：0，他引：1
搜集福建省火炬松人工林各30株林分平均木和优势木的树干解析数据，运用正态分布、对数正态分布、Weibull分布、B分布、Γ分布函数来拟合福建省火炬松人工林的直径分布规律。结果表明：Weibull分布的拟合效果好，标准地接受率为80％，用参数回收技术建立火炬松人工林直径分布收获模型，经检验，每公顷材积平均相对误差8．37％，每公顷胸高断面积平均相对误差6．72％。因此该模型可以用来估测福建省火炬松人工林的林分结构和产量。 相似文献
10.
The callus-fungal method was employed to test the response to C. flaccidum of the highly susceptible P. nigra var. laricio and the resistant P. sylvestris, and to ascertain whether results obtained with this method matched in planta observations. Calli were inoculated with axenie cultures of C. flaccidum obtained by incubating basidiospores on modified Schenk and Hildebrandt medium. Several parameters were evaluated. Colony growth was more rapid on P. nigra var. laricio. Colonies were dense on P. nigra var. laricio, but sparse on P. sylvestris. Aerial hyphae growth was abundant on P. nigra var. laricio, but less frequent on P. sylvestris. Hyphal branching began after 18 h on P. nigra var. laricio and after 45 h on P. sylvestris. Necrosis of the host cells set in after 24 h on P. nigra var. laricio, and after 70 h on P. sylvestris. The number of cells with plasmolysis was much larger in P. nigra var. laricio than in P. sylvestris. These results were consistent with the known resistance of the two species on whole plants. 相似文献
11.
12.
《Scandinavian Journal of Forest Research》2012,27(2):149-159
Abstract The dynamics of six different needle parameters of Pinus sylvestris L. and Pinus ponderosa Dougl. ex P. & C. Laws. were examined retrospectively for a 112-year-old mixed stand in Brandenburg, Germany, using the needle trace method. Similarities were found in needle production, needle loss and needle density. However, needle age, needle retention and total number of needles revealed significant differences between the tree species, with higher values for P. ponderosa. Pinus ponderosa yielded approximately twice as much mean whole-crown needle dry mass as P. sylvestris. Furthermore, different branching systems could be detected between the species, with both pines following “Corner's rule”. The results suggest that under identical growing conditions, P. ponderosa exhibits more efficient water use and can therefore maintain a bigger crown (as the basis for increased growth) than P. sylvestris. 相似文献
13.
Juvenile diameter distributions of loblolly pine characterized by the two-parameter Weibull function
Diameter distributions of juvenile loblolly pine (Pinus taeda L.) were characterized utilizing a two-parameter Weibull distribution to aid in forecasting and simulation of young stands. Juvenile diameter distributions were studied to gain insight into the effects of various stand-level factors. Results show that diameter distributions in juvenile loblolly pine stands can be successfully characterized with the two-parameter Weibull function. Repeated measures analysis detected significant planting density, age, and age by planting density interaction effects for the scale and shape parameter estimates from the two-parameter Weibull distribution. Using parameter recovery techniques, estimated diameter distributions were derived from easily attainable stand-level characteristics (i.e. basal area per hectare, planting density, age, and quadratic mean diameter). A thorough understanding of juvenile diameter distributions should prove especially useful for operational planning of stands on short rotations that require estimates of productivity at early ages. 相似文献
14.
Llu??s Coll Jos?? Ram??n Gonz??lez-Olabarria Blas Mola-Yudego Timo Pukkala Christian Messier 《European Journal of Forest Research》2011,130(1):55-65
In some areas of the Mediterranean basin where the understory stratum represents a critical fire hazard, managing the canopy cover to control the understory shrubby vegetation is an ecological alternative to the current mechanical management techniques. In this study, we determine the relationship between the overstory basal area and the cover of the understory shrubby vegetation for different dominant canopy species (Pinaceae and Fagaceae species) along a wide altitudinal gradient in the province of Catalonia (Spain). Analyses were conducted using data from the Spanish National Forest Inventory. At the regional scale, when all stands are analysed together, a strong negative relationship between mean shrub cover and site elevation was found. Among the Pinaceae species, we found fairly good relationships between stand basal area and the maximum development of the shrub stratum for species located at intermediate elevations (Pinus nigra, Pinus sylvestris). However, at the extremes of the elevation-climatic gradient (Pinus halepensis and Pinus uncinata stands), stand basal area explained very little of the shrub cover variation probably because microsite and topographic factors override its effect. Among the Fagaceae species, a negative relationship between basal area and the maximum development of the shrub stratum was found in Quercus humilis and Fagus sylvatica dominated stands but not in Quercus ilex. This can be due to the particular canopy structure and management history of Q. ilex stands. In conclusion, our study revealed a marked effect of the tree layer composition and the environment on the relationship between the development of the understory and overstory tree structure. More fine-grained studies are needed to provide forest managers with more detailed information about the relationship between these two forest strata. 相似文献
15.
Inoculation experiments were performed in order to evaluate the virulence of Gremmeniella abietina isolates from Spain on the main pine species planted in the Iberian Peninsula, as well as the influence of seedling age on this virulence. Two different experiments were carried out with four isolates of G. abietina from Spain. The greenhouse experiments consisted of seedling inoculations. One‐ and 2‐year‐old seedlings of the following five pine species were used: Pinus halepensis, Pinus pinea, Pinus pinaster, Pinus sylvestris and Pinus uncinata; also, 1‐year‐old seedlings of P. nigra were inoculated. The relative necrosis length (RNL) caused by the pathogen after 130 days was used as a response variable. The laboratory experiments were performed on 2‐ to 6‐year‐old internodes of the above pine species excluding P. uncinata. The necrosis length after 6 weeks of incubation was measured. The results have shown that all G. abietina isolates were pathogens on seedlings of these six pine species and seedlings of P. halepensis were consistently the most susceptible ones, although it is important to take into account that all the isolates used in the present work were isolated from P. halepensis, the only pine species in Spain where G. abietina has been recovered up to now. The susceptibility of the other pine species depended on the age of the seedlings. 相似文献
16.
Natalia Vizcaíno-Palomar Inés Ibáñez Marta Benito-Garzón Santiago C. González-Martínez Ricardo Alía 《New Forests》2017,48(3):363-379
Tree height-diameter allometry, the link between tree height and trunk diameter, reflects the evolutionary response of a particular species’ allocation patterns to above and belowground resources. As a result, it differs among and within species due to both local adaptation and phenotypic plasticity. These phenotypic variations in tree height-diameter allometry determine tree productivity, resistance and resilience to climate variation and, ultimately, the success of plant material used in restoration projects. We tested the effect of climate change and population origin on the phenotypic variation of tree allometry in four pine species at an early stage of development (ca. 11 years old) based upon data originated from multi-site provenance tests and planted along a wide climatic range in south-western Europe. For a representative sample of populations from each species, we used already-developed species-specific height-diameter allometric models to assess changes in allometry between present and future climatic conditions. We found that Pinus halepensis and Pinus pinaster were the most plastic species, while Pinus sylvestris and Pinus nigra showed negligible plastic responses. In addition, our models stressed that pine tree height-diameter allometry will change and phenotypic variation could increase, except in P. sylvestris, under future environmental conditions. For some of the species, this might allow the selection of phenotypes better suited to novel climatic conditions. These foreseeable changes in tree height-diameter allometry (among and within-species) could entail eco-evolutionary effects on the early forest plantation dynamics. Therefore, restoration and reforestation plans should consider these effects, as they may interfere with production and/or environmental goals. 相似文献
17.
Context
Families of the Gumbel (type I), Fréchet (type II) and Weibull (type III) distributions can be combined in the generalized extreme value (GEV) family of distributions. Maximum and minimum values of diameters in forest stands can be used in forest modelling, mainly to define parameters of the functions used in diameter class models as well as in some practical cases, such as modelling maximum diameters for sawing and processing purposes.Aims
The purpose of this study was to examine and compare two extreme value distribution functions (the Gumbel and the Weibull functions) in modelling the distribution of the minimum and the maximum values of representative sets of tree diameter samples. Both of these functions were applied to the lower and upper values of the diameter distributions of the main forest species in northwest Spain: Quercus robur L., Betula pubescens Ehrh., Pinus radiata D. Don, Pinus pinaster Ait. and Pinus sylvestris L.Methods
Parameters of the Gumbel function were estimated using the mode and the moments of the distributions, and parameters of the Weibull function were estimated using the moments method.Results
In general, the Weibull distribution was the most suitable model for describing the maximum diameters. The mode method of the Gumbel yielded the best results for minimum diameters of birch and Monterrey pine. The Gumbel distribution, fitted by either the mode- or moments-based methods, proved more suitable than the Weibull distribution for describing the minimum diameters in maritime pine and Scots pine stands.Conclusion
In some cases, better results were obtained with the Gumbel than the Weibull distribution for describing the distribution of extreme diameter values in forest stands in northwest Spain. This is the first example of the application of the Gumbel distribution in forest modelling. 相似文献18.
Inoculations by Peridermium pini (Pers) Lev. aeciospores ofscalpel wounds 2 mm deep on current year's Pinus sylvestrisL. shoots gave more numerous infections than shallower wounds.Some lesions resulting from these infections developed pycnidialdroplets and a few also produced aecial blisters within thefirst year after infection. Infection of P. sylvestris by P.pini can take place by direct stomatal penetration. This wasobserved only inside the needle sheaths of trees with previousnatural infections and was not observed on healthy trees. Thehyphae that developed from these penetrations passed intercellularlythrough the mesophyll to the vascular tissue where they proliferated. 相似文献
19.
20.
Teresa Bueis María Belén Turrión Felipe Bravo Valentín Pando Adele Muscolo 《Annals of Forest Science》2018,75(1):34