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Wyszukujesz frazę "dbh" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Application of growth traits and qualitative indices for selection of Scots pine (Pinus sylvestris L.) elite trees. A case study from Volyn region, western Ukraine
Autorzy:
Voitiuk, Vasyl
Andreieva, Valentyna
Kychyliuk, Oleksandr
Hetmanchuk, Anatolii
Klisz, Marcin
Mohytych, Vasyl
Powiązania:
https://bibliotekanauki.pl/articles/2041521.pdf
Data publikacji:
2020
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
tree breeding
half-sib families
progeny tests
DBH
height growth
Opis:
Since the plus trees are selected based on phenotype, it is necessary to evaluate them in progeny test. The aim of this study is an indication of selecting elite mother trees based on the results from half-sib progeny test trials. As study sites, two Scots pine half-sib progeny tests were selected. During evaluation, the progenies had reached the age of 38 and 40 years, respectively. In both progeny trials, quantitative parameters and qualitative traits of Scots pine half-sib progenies were investigated. Based on these data, complex evaluation of half-sib families was carried out. We concluded that, Scots pine progenies at the age of 38 and 40 years in fresh and moist mixed forests are characterised by acceptable quality, with the survival being 25%–33% per progeny test trial. Based on a complex evaluation of 38- and 40-year-old half-sib progenies of plus trees, we proposed to select 31% of tested plus/mother trees as candidates for elite trees. Further, the list of candidates for elite trees was created with five plus trees from the Volyn region (26% of the total tested from the region) and four plus trees from the Lviv region (40% of the total tested from the region). With age, the share of the best and undesirable trees decreases, while the proportion of intermediate trees increases in both control trees and half-sib progenies. At the age of 38 and 40 years, the proportion of fast-growing offspring was from 0% to 36%, while the declining trend that was observed in previous years was being continued. Thus, due to the declining trend in the proportion of fast-growing offspring observed at the age of 38 and 40 years, we propose to select candidate trees for an elite group not early than after 40 years of test their progenies.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2020, 62, 3; 199-209
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Population structure and regeneration status of most abundant medicinal woody plants in Mabira Central Forest Reserve management zones
Autorzy:
Tumuhe, C.L.
Mwine, R.N.
Manana, S.
Powiązania:
https://bibliotekanauki.pl/articles/2049704.pdf
Data publikacji:
2018
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
woody plant
medicinal plant
population structure
regeneration
breast height diameter
forest reserve
Mabira Forest Reserve
management zone
dbh
central forest reserve
medicinal plants
Opis:
In the rural areas 90% of the Ugandans use plants for their medicinal uses. Communities around Mabira Central Forest Reserve (CFR) harvest plants for medicinal purposes. The increased uptake of herbal medicine is a threat to the abundance and health of medicinal trees. This research determined the species population structure and regeneration status of most abundant woody medicinal plant species in Mabira CFR. Sixty nested plots measuring 20×10 m were established adjacent to transects, 20 plots per management zone. The species sampled were identified, counted, and their diameter at breast height (dbh) taken. Their density was computed. Using the dbh classes and density data, dbh distributions were established. Using Kruskal- Wallis test we ascertained if significant differences existed in medicinal plant species densities for size classes in the 3 zones. Using linear regression we got relationship between plant density and dbh. A regression analysis of In (Ni+1) against di was made to cater for the zero values of abundance per hectare. The population had a steep negative slope, meaning that it is stable and naturally replacing itself. There was a general decline in species density with dbh. The <5 dbh size class had the biggest number of individuals per hectare in the production zone. The production zone had a high regeneration potential due to most individuals being in the smallest size class. Density had a negative linear relationship with dbh. There was a significant relationship between dbh and density of species. The tree species sampled were generally naturally regenerating.
Źródło:
Environment, Earth and Ecology; 2018, 2, 1; 6-11
2543-9774
2451-4225
Pojawia się w:
Environment, Earth and Ecology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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