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Wyszukujesz frazę "forest modelling" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
Wykorzystanie modelu macierzowego do prognozowania rozwoju drzewostanów o złożonej postaci
Application of matrix model for projecting the development of stands with complex structure
Autorzy:
Drozdowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/1019340.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
drzewostany
wykorzystanie
modele macierzowe
prognozowanie
lesnictwo
modele matematyczne
rozwoj drzewostanu
forest modelling
linear and non−linear programming
stand with complex structure
silvicultural planning
Opis:
In this study, the principles of building, parameterisation and validation of matrix models of stands are presented. Three basic processes occurring in stand development such as regeneration, growth and dieback of trees are discussed. The study points out to the potential advantages and directions of application of stand matrix models in solving silvicultural problems.
Źródło:
Sylwan; 2006, 150, 02; 3-13
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Premises for the construction of balance equations of water reserves in the saturation zone of forest soil
Przesłanki do konstrukcji równań bilansowych zapasu wody w strefie saturacji gleb leśnych
Autorzy:
Suliński, J.
Owsiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/292927.pdf
Data publikacji:
2009
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
bilans wodny lasu
hydrologia leśna
leśnictwo
modelowanie matematyczne
zapas wody w glebie
forestry
forest hydrology
mathematical modelling
soil water reserve
water budget in a forest
Opis:
Premises for the construction of balance equations of water reserves in the saturation zone of forest soil are presented in this paper. Changes of soil water reserves are dealt with as an effect of the atmosphere-tree stand-soil balance at the assumption of constant ground water flow and negligibly small losses for infiltration down the soil profile below saturation zone. These assumptions are met in permeable lowland forest soils, particularly in areas where the aquifer is situated on relatively shallow impermeable substratum. Then, for snow-free periods, it is possible to: 1) combine the increment of soil water reserves with precipitation above tree crowns and with plant and litter interception and 2) combine the losses of soil water reserves with plant transpiration and evaporation from the soil surface. The periods of increments and losses of soil water reserves are determined from limni-graph records of ground water table depth in piesometers. Examples are given in the paper of equations identified by long term data from 13 soil profiles localised in pine forests on Pleistocene floodplain of the Dunajec River. The data included: ground water table depth, physical properties of grounds in soil profiles, and hydro-climatic conditions. The equations combine increments and losses of water reserves in the saturation zone with rainfall and deficits of air humidity measured on a mid-forest meadow.
W pracy przedstawiono przesłanki do konstrukcji równań bilansu wody w strefie saturacji gleb leśnych. Zmiany zapasu wody w glebie są traktowane jako wynik bilansu atmosfera-drzewostan-gleba, z założeniem ruchu ciągłego wody gruntowej, oraz zaniedbywalnie małych strat na infiltrację w głąb profilu, poniżej strefy saturacji. Założenia te są spełnione w wysokim stopniu w nizinnych glebach leśnych, przepuszczalnych od powierzchni, szczególnie na tych obszarach, na którym warstwa wodonośna znajduje się na stosunkowo płytko położonym stropie utworów nieprzepuszczalnych. Wówczas w okresach bez pokrywy śniegowej możliwe jest: (1) związanie przyrostu zapasu wody glebowej z opadem nad koronami drzew i intercepcją roślin oraz ściółki, (2) związanie ubytków zapasu wody glebowej z transpiracją roślin i parowaniem z powierzchni gleby. Okresy przyrostów i ubytków zapasu wody glebowej są wyznaczane na podstawie zapisu limnigraficznego głębokości zwierciadła wody gruntowej w piezometrach. W pracy podano przykłady równań opracowanych na podstawie danych z wieloletnich pomiarów w 13 profilach glebowych zlokalizowanych w lasach sosnowych na plejstoceńskiej terasie Dunajca, tj.: 1) głębokości zwierciadła wody gruntowej, 2) właściwości fizycznych gruntów budujących profile glebowe, 3) warunków hydroklimatycznych. Równania te wiążą przyrosty i ubytki zapasu wody w strefie saturacji z opadami deszczu i niedosytami wilgotności powietrza, pomierzonymi na śródleśnej łące.
Źródło:
Journal of Water and Land Development; 2009, no. 13b; 87-108
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocenka ehkspluatacionnykh svojjstv kolesnogo trelovechnogo traktora
Exploitation properties valuation of wheel tralling tractor
Autorzy:
Bilyk, B.
Borys, M.
Mokhov, S.
Simanovich, V.
Powiązania:
https://bibliotekanauki.pl/articles/77673.pdf
Data publikacji:
2013
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
transmission
dynamic process
dynamic load
work condition
forest machine
wheel tractor
computer programme
fuel economy
mathematical modelling
Opis:
The analysis of the work conditions of forest tractors and machines at their base, and the impact of these conditions on the performance properties of tractors. Calculated scheme of dynamic model of transmission biaxial wheel tractor and computer program has been developed for the tractor movement simulation and dynamic processes in the transmission that allows you to explore the influence of weight and geometric parameters, engine power and the transmission gear number on its speed properties, coefficients of dynamic and fuel economy. It was presented the results of mathematical modeling of the dispersal from the place and dynamic loadings in the transmission of a wheel tralling machine. The dependences of the dynamics coefficients, of the determination of the fuel’s economy and speed property on gear numbers of the transmission’s aggregates was received. It was substantiated the rational significances of the gear numbers of distribute box of a wood tractor, that will reduce dynamic moments, and therefore increase the work durability of the wheel forest transport machine.
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2013, 15, 4
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie wielkości użytkowania rębnego drzewostanów w zależności od przyjętych metod prognozowania rozwoju lasu
Modelling of the size of allowable cutting based on adopted methods of forest development forecast
Autorzy:
Szyc, K.
Borecki, T.
Stępień, E.
Kędziora, W.
Konieczny, A.
Orzechowski, M.
Wójcik, R.
Powiązania:
https://bibliotekanauki.pl/articles/979061.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
forestry use
forest development
modelling of usage regulation
Opis:
Many attempts have been made to develop a strategy for regulating forest use consistent with the multifunctional forest model. In this paper we present two proprietary methodologies of regulation of the allowable cutting size in a multifunctional forest in the 60−year time perspective. We assumed that all restrictions of nature protection and non−productive functions of the forest would still be in force. We based the first method on age class tables (TKW), which is faster but less exact in terms of spatial order of felling. The tree stand method (D−STAN) is based on stands spatial order and the cutting direction basis. In both cases, we based the temporal felling order on species rotation age. Comparing the results, we noticed that they present similar trends in the age structure of tree stands in younger age classes. The main discrepancies of the forecast concerns the share of forest stands in a complex structure: the TKW method gave approximately 12,4%, while the D−STAN one produced 5,1%. The latter approach shows that much smaller areas of stands are used for reconstruction. That marker is influenced by the spatial order of cutting used in the D−STAN model. In conclusion, we suggest to return to the big−area clear−cutting system on fresh coniferous habitats. Medium−area clear−cuttings should be brought back on the least fertile fresh mixed coniferous forests and possibly even fresh mixed deciduous forests.
Źródło:
Sylwan; 2020, 164, 04; 280-291
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele struktury grubości w dwu- i wielopiętrowych drzewostanach z udziałem jodły Abies alba Mill. i buka Fagus sylvatica L.
Models of diameter structure in two- and multi-storied stands with fir Abies alba Mill. and beech Fagus sylvatica L.
Autorzy:
Pach, M.
Podlaski, R.
Powiązania:
https://bibliotekanauki.pl/articles/989729.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany mieszane
struktura grubosci
drzewostany dwupietrowe
drzewostany wielopietrowe
jodla pospolita
Abies Alba
buk zwyczajny
Fagus sylvatica
rozklad piersnic
rozklad Weibulla
rozklad mieszany
tree diameter modelling
forest complex structure
weibull mixture model
Opis:
The objectives of the study were (1) to determine the models of diameter at breast height (dbh) distributions in two− and multi−storied mixed stands with fir Abies alba Mill. and beech Fagus sylvatica L. as well as (2) to assess the usefulness of single Weibull distribution and two−component mixture of Weibull distribution to approximation of empirical dbh distributions for distinguished models of dbh structures. In the Świętokrzyskie Mountains, 21 sample plots ranging in size from 0.2 to 0.4 ha were established. To identify the models of dbh distributions, in two− and multi−storied stands with similar empirical dbh distributions, the hierarchical cluster analysis (HCA) with the Jaccard's measure and the Ward's minimum variance agglomeration method were used. To approximate dbh distributions, the single Weibull distribution and the two−component mixture of Weibull distribution were employed. In two− and multi−storied mixed stands with fir and beech, with the mean age between 50 and 70 at the dbh, four models of dbh distributions were determined (fig. 1). Two of them were decreasing, strongly asymmetric (OS and OJ models; fig. 2) and the other two were increasing in the initial phase and decreasing in the final, having two maximums (DM1 and DM2 models; fig. 3). In the stands with the complex structure mixed distribution should be used to approximate empirical data. The analysis revealed high suitability and versatility of Weibull distribution both as single form and two−component mixture.
Źródło:
Sylwan; 2015, 159, 08; 632-638
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele stosowane do opisu architektury drzew i możliwości ich praktycznego wykorzystania w leśnictwie
Tree architecture descriptive models with forestry applications
Autorzy:
Kędra, K.
Stereńczak, K.
Gazda, A.
Powiązania:
https://bibliotekanauki.pl/articles/978911.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
forest modelling
forest ecosystems
remote sensing
geometry
Opis:
The qualitative and quantitative descriptive models of tree architecture differ in the degree of complexity and the way of mapping tree structure, and thus, are of varied use in forestry. The qualitative, Hallé−Oldeman models, serve as a framework for analyzing tree architecture and help define the different components of a tree branching system. Among the quantitative models (here: horizontal, three−dimensional or vertical ones) the horizontal representations are the most parsimonious, and proved to be useful for examining the effects of competition process and the light conditions within the forest understory. The three−dimensional representations (Quantitative Structural Models; QSMs) have the widest range of applications as they may be used for deriving both the two−dimensional traits (such as crown length or branch height) and the volumetric traits (such as tree crown volume or wood volume). At the same time they are the most complex ones. The vertical models were used to study the impact of local terrain shape and wind conditions on tree architecture, but the way of deriving such models from the QSMs seems excessively laborious. However, we highlight here also a photogrammetric method, which allows to obtain an analogous model in much simpler way. Both three−dimensional and vertical representations are useful for determining the wood quality features. Three−dimensional models can be used to accurately measure tree woody biomass, while horizontal models can be used for reliable biomass estimations.
Źródło:
Sylwan; 2020, 164, 09; 707-718
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increasing Sustainability of European Forests: Modelling for Security Against Invasive Pests and Pathogens under Climate Change
Autorzy:
Nowakowska, J.A.
Powiązania:
https://bibliotekanauki.pl/articles/38386.pdf
Data publikacji:
2013
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
forest
Europe
European project
ISEFOR project
modelling
invasive pest
pathogen
climate change
forest health
forest ecosystem
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2013, 55, 1
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating parameters of empirical infiltration models from the global dataset using machine learning
Autorzy:
Kim, S.
Karahan, G.
Sharma, M.
Pachepsky, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2083049.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
infiltration modelling
random forest
Soil Water
Infiltration Global database
Opis:
It is beneficial to develop pedotransfer relationships to estimate infiltration equation coefficients in site-specific conditions from readily available data. No systematic studies have been published concerning the relationships between the accuracy of the infiltration equation and the accuracy of the predicted coefficients in this equation. The objective of this work was to test the hypothesis that, for the same infiltration data, the accuracy of pedotransfer predictions for coefficients in an infiltration equation is greater for the infiltration equation that performs better. The hypothesis was tested using the commonly employed Horton and Mezencev (modified Kostiakov) infiltration equations with data from the Soil Water Infiltration Global database. The random forest machine learning algorithm was used to develop the pedotransfer model. The Horton and the Mezencev models performed better with 928 and 758 datasets, respectively. The accuracy of the estimates of the infiltration equation coefficients did not differ substantially between the estimates obtained from all data and from the data where the infiltration equation had lower root-mean-squared error values. The root-mean-squared error values of the pedotransfer estimates decreased by 2 to 25% when only datasets with the same infiltration measurement method were considered. The development of predictive pedotransfer equations with the data obtained from the same infiltration measurement method is recommended.
Źródło:
International Agrophysics; 2021, 35, 1; 73-81
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating forest biomass by remote sensing RADAR data in Brazil
Autorzy:
Santos, J.R.
Gama, F.F.
da Conceicao Bispo, P.
Powiązania:
https://bibliotekanauki.pl/articles/52438.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
forest biomass
biomass modelling
forest inventory
tropical forest
remote sensing
eucalyptus tree
stand
RADAR data
Brazil
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 192
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimates and forecasts of forest biomass and carbon sequestration in North America and Australia: a forty-five year quest
Autorzy:
Botkin, D.B.
Ngugi, M.R.
Doley, D.
Powiązania:
https://bibliotekanauki.pl/articles/52742.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
estimation
forecast
forest biomass
forest modelling
forest inventory
biomass inventory
model validation
carbon sequestration
North America
Australia
Opis:
A half-century of forest inventory research involving statistically-valid fieldmeasurements (using statistically representative sample size and showing confidence limits) and well-validated forecasting methods are reviewed in this paper. Some current procedures overestimate global and large-scale forest biomass, carbonstorage, and carbon sequestering rates because they are based on statistically-invalid methods (errors in estimates are unavailable and unreported), or they fail to consider key dynamic characteristics of forests. It is sometimes assumed that old-growth forests can serve as fixed, steady-state storage of biomass and carbon for indefinitely long periods, but it is shown by both modelling and remote sensing that forests are dynamic systems, the state of which can change considerably over as shorta time as a decade. Forecasting methods show that maximum biomass and carbon storage in some important forest types occurs in mid-succession, not in old-growth. It is proposed, therefore, that realistic biomass and carbon storage estimates used for carbon credits and offsets be determined as the statistical mean minus the confidence interval and that practical carbon sequestering programs include specific timeframes, not indefinitely long periods of time.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 192
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution and habitat conditions of Pinus cembra forests in the Tatra Mountains
Autorzy:
Zieba, A.
Rozanski, W.
Bukowski, M.
Ciesielska, B.
Szwagrzyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/2077747.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
subalpine forest
Natura 2000 habitat
GIS analysis
habitat modelling
Opis:
Relic Pinus cembra forests were among the least studied plant communities in the Western Car- pathians. Their distribution in this mountain range is limited only to the Tatras. The lack of comprehensive research on the Polish and Slovakian sides of the Tatras led to considerable discrepancy regarding their distribution (300–1170 ha) as well as habitat conditions. Their occurrence on limestones and in the West- ern Tatras was contested. Therefore, the aim of this work was to determine the distribution and habitat conditions for the occurrence of Swiss stone pine forests in the Tatras. We mapped the entire range of the distribution of these forests, using the topographic method and digitized it in ArcGIS 10.2.2. Afterwards, we undertook spatial analysis, using DEM regarding their occurrence, depending on: altitude, inclination, solar radiation, exposure, geology and soil. To determine the preferable site conditions we used the logistic regression model. The total area of P. cembra forests in the Tatras is 916.93 ha. They occur in all mountain ranges within the Tatras. Altitude, inclination and solar radiation have significant impacts on the occur- rence of these forests. The odds of the occurrence of P. cembra forests increased by 0.5% for every 1 m of altitude, by 2% for every 1° of inclination and decrease by 0.1% for every 1 MJ/m2/year of solar radiation. The majority of these forests grow in the altitude range 1300–1650 m a.s.l. (95%) and on slopes with 20–60° inclinations (80%). Swiss stone pine forests occur both on slopes with low (1900 MJ/m2) and high annual solar radiation (3400 MJ/m2). They prefer slopes with North-western exposure. They may grow both on granite and limestone, while the majority of them were mapped on granite. Pinus cembra forests grow on diverse soils, both acidic and alkaline. Nevertheless, most of them occur on Haplic Podzols (52%). The results may be applicable to the Tatra National Park for the conservation and monitoring of this Natura 2000 habitat.
Źródło:
Dendrobiology; 2019, 81; 86-96
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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