Looduslikult uuenenud noorendike kõrguskasvu dünaamika analüüs Järvselja püsikatsealadel
Laen...
Kuupäev
2013
Kättesaadav alates
ainult raamatukogus, only in library
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Hinnates puistus puude kasvu noores eas, on võimalik teha olulisi prognoose puistu
edasise kasvu kohta. Siiani pole noorte, eelkõige looduslikult uuenenud
lehtpuuenamusega puistute kõrgusjaotusi Eestis uuritud. Kuid just nimetatud puistute
osakaal on viimastel aastakümnetel suurenenud. Käesoleva töö eesmärgiks oli uurida
noorendike puude kõrgusjaotuste ja juurdekasvude dünaamikat. Analüüsis kasutati
2005. aastal Järvselja Õppe- ja Katsemetskonnas rajatud noorendike katseala
2005…2012 mõõtmisandmeid. Andmetöötluseks kasutati statistikaprogrammi R.
Kontrolliti Weibulli jaotuse sobivust empiiriliste kõrgusjaotuste lähendamiseks, ning
analüüsiti Weibulli parameetrite sõltuvust puistu takseertunnustest. Aastaste
juurdekasvude hindamiseks loodi juurdekasvumudel, ning hinnati mudeli faktorite
mõju osatähtust juurdekasvule. Analüüsil selgus, et noorendike empiirilised
kõrgusjaotused pole statistiliste hinnangute alusel üldjuhul teoreetilise jaotusega, kuid
paljudel juhtudel on jaotuste üldkujud sarnased. Weibulli jaotuse parameetrite
hindamisel ilmnes, et ajalises skaalas on kujuparameetri väärtused langeva ning
mastaabiparameeter tõusva trendiga. Noorendike puude juurdekasvude analüüs näitas,
et enim mõjutab juurdekasvu konkreetne kasvuaasta, mitte aga puuliik, ega puu vanus.
Assessing the growth of forest stand trees in young age, it is possible to make significant prognosis for successive growth of forest stand. Height distribution patterns of young, especially naturally regenerated broadleaves forest stands have not been studied this far in Estonia. Aforenamed forest stand relative importance has increased over the last few decades. The aim of this paper was to examine the height distribution and accretion dynamics of young forests. Measuring data used in the analysis originated from the Järvselja Training and Experimental Forest Center, which was built as an experimental field in 2005. The data used in this paper, was from the years 2005 to 2012. Statistics program R was used to analyze data. Suitability of Weibull`s distribution was examined for empirical draw together of height distribution, also Weibull`s dependence on forest stand assessable feature parameters was analyzed. Model of accretion was created in order to assess yearly accretion, also influence of model factors on accretion was assessed. Analysis shows that empirical height distributions of young regenerated forests are not, according to statistical assay, mostly theoretical distributions, but in many cases distribution configurations resemble. Assessment of Weibull`s distribution parameters showed that on time scale, shape parameter values are decreasing, and scale parameter tendency was increasing. The analysis of trees in young regenerated forests showed that increasement is mostly influenced by particular year of growth, and not by type or age of the tree.
Assessing the growth of forest stand trees in young age, it is possible to make significant prognosis for successive growth of forest stand. Height distribution patterns of young, especially naturally regenerated broadleaves forest stands have not been studied this far in Estonia. Aforenamed forest stand relative importance has increased over the last few decades. The aim of this paper was to examine the height distribution and accretion dynamics of young forests. Measuring data used in the analysis originated from the Järvselja Training and Experimental Forest Center, which was built as an experimental field in 2005. The data used in this paper, was from the years 2005 to 2012. Statistics program R was used to analyze data. Suitability of Weibull`s distribution was examined for empirical draw together of height distribution, also Weibull`s dependence on forest stand assessable feature parameters was analyzed. Model of accretion was created in order to assess yearly accretion, also influence of model factors on accretion was assessed. Analysis shows that empirical height distributions of young regenerated forests are not, according to statistical assay, mostly theoretical distributions, but in many cases distribution configurations resemble. Assessment of Weibull`s distribution parameters showed that on time scale, shape parameter values are decreasing, and scale parameter tendency was increasing. The analysis of trees in young regenerated forests showed that increasement is mostly influenced by particular year of growth, and not by type or age of the tree.
Kirjeldus
Märksõnad
noorendikud, kõrgusjaotused, Weibulli jaotus, juurdekasv, modelleerimine (teadus), magistritööd