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Wyszukujesz frazę "tree density" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Ekologiczne konsekwencje hodowli drzew w różnym zagęszczeniu I. Wzrost i rozwój drzewostanu
Ecological consequences of silviculture at variable stand densities. I. Stand growth and development
Autorzy:
Jagodziński, A.M.
Oleksyn, J.
Powiązania:
https://bibliotekanauki.pl/articles/1012013.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
wzrost drzewostanu
wiezba drzew
zageszczenie poczatkowe
drzewostany
lesnictwo
zageszczenie roslin
rozwoj drzewostanu
stand density
spacing
tree competition
tree biometry
stand growth and development
review
Opis:
The main goal of this review was to characterize ecological consequences of growing trees at variable stand densities. We found that the majority of studies were focused on biometry, productivity and mortality of trees, and wood quality and its economic value, while the influence of stand density on biomass allocation, abiotic and biotic factors, chemistry of different tree organs, diversity and biomass of understory plants, ecophysiology of trees and microclimate conditions (e.g. temperature, humidity, light conditions, etc.) were only occasionally addressed. Stand growth and development trajectories are clearly modified by stand density, however the strength of influence depends on the phase of stand development. Lower seedling densities in nursery conditions lead to increases in their height and diameter, thus influencing seedling quality used in afforestation. The positive influence of higher density on diameter and height of trees in younger stages of stand development may be a result of higher probability of seedlings being planted in more favorable microhabitats, improvement of microclimate conditions, earlier crown closure that reduces interspecific competition for nutrient and water resources. Moreover, stand density clearly influences branch diameter and length, and thus knot size. Higher stand density results in earlier crown closure and higher tree mortality, leading to vertical and horizontal changes in stand structure (DBH, height and crown dimensions of trees). In the denser stands slender and flexible trees with small, narrow crowns dominate, and most of the trees belong to the 3rd class according to Kraft' classification of tree social positions in the stand. The influence of stand density on stand structure may lead to changes in biomass partitioning and thus merchantable wood production and nutrient retention in particular tree organs.
Źródło:
Sylwan; 2009, 153, 02; 75-85
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekologiczne konsekwencje hodowli drzew w różnym zagęszczeniu III. Stabilność drzewostanu, fitoklimat i różnorodność biologiczna
Ecological consequences of silviculture at variable stand densities. III. Stand stability, phytoclimate and biodiversity
Autorzy:
Jagodziński, A.M.
Oleksyn, J.
Powiązania:
https://bibliotekanauki.pl/articles/1011879.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
wiezba drzew
zageszczenie poczatkowe
drzewostany
roznorodnosc biologiczna
mikroklimat
lesnictwo
ekologia lasu
stabilnosc drzewostanu
zageszczenie roslin
stand density
spacing
tree competition
forest ecology
stand stability
microclimate
biodiversity
review
Opis:
The main goal of this review was to characterize ecological consequences of growing trees at variable stand densities. We analyzed the influence of stand density on its mechanical and biological stability, diversity and biomass of understory plants and microclimate conditions (e.g. temperature, humidity, light, etc.). Higher stand density results in higher susceptibility to wind and snow damage, due to changes in height to diameter ratio (tree slenderness). The mechanical stability of stands may be promoted by silvicultural activities such as light thinning applied before growth stagnation. In addition, the reduction of stand density during stand development may increase biomass allocation to coarse roots that stabilize trees in the soil. High tree density may increase stand susceptibility to pathogens and insects and thus increase tree mortality. Trees growing at higher density (with higher intraspecific competition) may allocate less assimilates for defense against herbivorous insects and pathogens. The effect of tree density on stability of multi−species stands is inconclusive, since such studies were only occasionally undertaken. Since tree density influences light conditions (mainly before canopy closure), there is a negative relationship between stand density and herbaceous species diversity and biomass. Based on the published data, we summarized consequences of silviculture at different stand densities and proposed future directions of research needed to fill the gaps in current knowledge. Understanding the long−term ecological consequences of variable stand densities is essential for development of sustainable and stable forest ecosystems.
Źródło:
Sylwan; 2009, 153, 04; 219-230
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekologiczne konsekwencje hodowli drzew w różnym zagęszczeniu II. Produkcja i alokacja biomasy, retencja biogenów
Ecological consequences of silviculture at variable stand densities. II. Biomass production and allocation, nutrient retention
Autorzy:
Jagodziński, A.M.
Oleksyn, J.
Powiązania:
https://bibliotekanauki.pl/articles/1011811.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
wiezba drzew
zageszczenie poczatkowe
mikroelementy
lesnictwo
skladniki pokarmowe
ekologia lasu
makroelementy
zageszczenie roslin
dostepnosc skladnikow pokarmowych
wymiana gazowa
drzewostany
biomasa
alokacja biomasy
stand density
spacing
tree competition
forest ecology
biomass allocation
nutrient retention
review
Opis:
The main goal of this review was to characterize ecological consequences of growing trees at variable stand densities. Increasing stand density results in rising competition among trees in their below− and above− ground parts, leads to changes in stand structure (DBH, height, crown width and length, crown ratio, tree slenderness, branch diameters and length) and thus modifies biomass partitioning and may influence stand productivity. Trees grown at higher density compete more intensely for limited resources such as space, light, water and nutrients, than in those grown at wider spacing. In general, total tree biomass accumulation is higher in more dense stands and in less dense stands a higher proportion of biomass is allocated to coarse roots. Moreover, stand density may alter foliage distribution within the crowns. For stands grown at higher tree density, leaf area index (LAI) may increase and thus influence stand productivity, however LAI is closely related to light requirements and succession status of the species. Because stand density may simultaneously modify macro− and micronutrient concentration in different tree tissues and biomass partitioning, it may lead to distinct changes in the nutrient balance of the forest ecosystem. For example, a considerable pool of stand mineral elements (including carbon) is allocated to roots that are not subjected to traditional stand management. Therefore, manipulation of stand density leading to higher biomass allocation to roots may increase carbon sequestration in forest ecosystems.
Źródło:
Sylwan; 2009, 153, 03; 147-157
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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