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Wyszukujesz frazę "species structure" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Implication of forest zonation on tree species composition, diversity and structure in Mabira Forest, Uganda
Autorzy:
Weldemariam, E.C.
Jakisa, E.S.
Ahebwe, D.A.
Powiązania:
https://bibliotekanauki.pl/articles/9997.pdf
Data publikacji:
2017
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
forest zonation
management zone
tree
woody species
plant species
species composition
species diversity
species structure
Mabira Forest Reserve
Uganda
Opis:
The study aimed to investigate effectiveness of forest management zoning in conserving biodiversity of Mabira forest reserve. The study sites buffer, production, and strict nature reserve management zones were purposively selected. This was undertaken through investigating woody species diversity, composition and structure. A total of 60 sampling plots with a size of 20 m x10 m were used to collect vegetation data. Variables such as woody plant species identification and counts as well as diameter at breast height (DBH) of trees were done. The result depicted a total of 65 woody species; 39 in buffer, 19 in productions and 37 in strict nature reserve. Of these, only 9 trees species were found common to all zones and their Sorensen similarity coefficient was 0.2213. The population structure of the buffer and strict nature reserve zones was found to be a J - shape pattern, whereas the production zone shown an inverted J-shape pattern. Higher woody species diversity was depicted in the buffer and strict nature zones with (H’=2. 73512) and (H’=2. 68412) respectively, and lower in a production zone (H’=1. 63628). The evenness index value of a buffer zone was (J =0. 746574), strict nature (J= 0.743335) and production (J=0. 555719). The production zone had shown higher IVI values followed by buffer and strict nature reserve zone. The most important woody species identified based on their IVI value were Broussonetia papyrifera (Production), Acalypha neptunica (Buffer), Funtumia Elastica (strict nature reserve). The existing forest management is effective in conserving the biodiversity of the forest reserve. Nevertheless, the production zone was still suffering from exploitation of the surrounding community, hence serve for protecting the remaining management zones from further human interference. Further investigation is also required on the adjacent community perceptions of the forest management zoning.
Źródło:
Environment, Earth and Ecology; 2017, 1, 1
2543-9774
2451-4225
Pojawia się w:
Environment, Earth and Ecology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytosociological structure of Cladonio-Pinetum Juraszek 1927 of the Western Polissya of Ukraine
Fitosocjologiczna struktura borów chrobotkowych Cladonio-Pinetum Juraszek 1927 z Polesia na terenie zachodniej Ukrainy
Autorzy:
Mertsalo, M.
Soroka, M.
Powiązania:
https://bibliotekanauki.pl/articles/791412.pdf
Data publikacji:
2017
Wydawca:
Wyższa Szkoła Zarządzania Środowiskiem w Tucholi
Tematy:
phytosociological structure
Cladonio-Pinetum habitat
lichen
moss
species composition
pine forest
Scotch pine
Ukraine
Źródło:
Zarządzanie Ochroną Przyrody w Lasach; 2017, 11
2081-1438
2391-4106
Pojawia się w:
Zarządzanie Ochroną Przyrody w Lasach
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of phytoplankton size-structure based productivity, pigment complexes (HPLC/CHEMTAX) and species composition in the Cochin estuary (Southwest coast of India): special emphasis on diatoms
Autorzy:
Paul, M.
Valappan, M.N.
Nanappan, U.
Gopinath, V.
Velloth, R.T.
Rajendran, A.
Nair, M.
Peariya, A.
Powiązania:
https://bibliotekanauki.pl/articles/2078766.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton
size structure
photopigment
species composition
diatom
chlorophyll a
primary production
seasonality
high performance liquid chromatography
chemotaxonomy
India
Opis:
Seasonal studies on size-fractionated phytoplankton productivity (biomass and primary production), marker pigments, and species composition and abundance were carried out in the Cochin estuary (CE), located on the southwest coast of India, to identify the critical environmental factors that control the consistent preponderance of diatoms. The overall results of the study showed a significant contribution of small-sized phytoplankton, specifically nanophytoplankton (2—20 μm), to the total chlorophyll a and primary production in the estuary, regardless of seasons. Diatoms constituted the major phytoplankton taxa, showed an exceptional seasonal scale increase in numerical abundance during the post-southwest monsoon. The relative increase in fucoxanthin (biomarker of diatoms) over other marker pigments substantiated the numerical dominance of diatoms throughout the sampling periods. This is the first study in the CE in which phytoplankton marker pigments have been detected and elucidated the seasonality of functional groups based on HPLC/chemotaxonomy analytical approaches. The prevalence of high DiatDP and diatom chlorophyll a equivalent (estimated by CHEMTAX), further confirmed the preponderance of diatoms in the CE, despite the intermittent dominance of cyanophytes and cryptophytes (monsoon period). The consistent increase in SPM levels (> 25 mg L—1), established at all sampling stations, indicated that the water column turbidity might be one of the significant environmental factors hindering the growth of large-sized phytoplankton (ca. >20 μm) in the CE even if the system invariably holds high inorganic nutrients, irrespective of seasons
Źródło:
Oceanologia; 2021, 63, 4; 463-481
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and dynamics of selected stands of primeval character in the Pieniny National Park
Autorzy:
Jaworski, A
Podlaski, R.
Powiązania:
https://bibliotekanauki.pl/articles/41477.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Pieniny National Park
forest
species composition
structure
stand
development stage
fir
Abies alba
beech
Fagus sylvatica
plant regression
Opis:
The purpose of this study was to determine changes which occurred during 23 years (1974–1997) in four stands in respect of species composition, structure, developmental stages and phases. In 1997 the Walusiowka stand represented the growing up stage, phase of a multistory structure, and during the study period its volume decreased from 698 to 676 m3/ha.The Przełęcz Sosnow stand was in the growing up stage, phase of a little diversified storied structure and regeneration, and its volume decreased from 696 to 622 m3/ha.The Grodek stand during the entire study period was in the growing up stage, phase of the selection forest structure and regeneration, and its volume increased from 529 to 585 m3/ha.The Facimiech stand in 1997 was in the optimum stage, phase of aging and regeneration, and its volume decreased from 688 to 661 m3/ha.During 1974–1997 the percentage of fir (Abies alba) considerably decreased in three stands (Walusiowka from 46 to 33%, Przełęcz Sosnow from 58 to 36%, Grodek from 42 to 24%).The Facimiech stand was almost a pure fir stand during the entire control period. In the Przełęcz Sosnow stand, due to a rapid mortality of fir and presence of vital trees of beech (Fagus sylvatica) of the growing up and optimum growth generations, the break up stage did not take place but the growing up stage had developed, which indicated the disturbance of the natural cycle of the primeval forest described by Korpel’. A scarce presence of fir upgrowth and prevalence of beech in stands composed of these two species permits to suppose that fir will be retreating in favor of beech.
Źródło:
Dendrobiology; 2007, 58; 25-41
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytoplankton size structure and species composition as an indicator of trophic status in transitional ecosystems: the case study of a Mediterranean fjord-like karstic bay
Autorzy:
Bosak, S.
Silovic, T.
Ljubesic, Z.
Kuspilic, G.
Pestoric, B.
Krivokapic, S.
Vilicic, D.
Powiązania:
https://bibliotekanauki.pl/articles/48711.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton community
size structure
species composition
trophic status
ecosystem
aquatic ecosystem
picophytoplankton
Adriatic Sea
Boka Kotorska Bay
karstic bay
Opis:
The species composition and size-structure of the phytoplankton community in the Boka Kotorska Bay (SE Adriatic Sea) were analysed with respect to abundance and carbon biomass, together with the physico-chemical parameters, with the aim of evaluating the predefined oligo-mesotrophic status of this transitional water ecosystem. Three stations located in the inner part of the Bay were sampled with seasonal frequency in 2008/2009. Picophytoplankton cells were counted using flow cytometry; nanophytoplankton and microphytoplankton were identified and counted by light microscopy. The relative importance of the picoplankton in the Bay, in terms of both abundance and biomass, during all the investigated seasons emphasized their significance in the phytoplankton community. Picocyanobacteria (Synechococcus) constituted a significant part of the summer assemblages with regard to both abundance (up to 3.38 × 108 cells L−1) and carbon biomass (up to 73% of total phytoplankton carbon). The contribution of the nanophytoplankton was found to be generally low (<20% of the total phytoplankton carbon) in all seasons, and was dominated by autotrophic/mixotrophic flagellates. Species with a preference towards nutrient-enriched conditions, like the diatom Skeletonema marinoi, dominated the microphytoplankton fraction. S. marinoi was the most abundant in spring/winter (up to 2.86×106 cells L−1) above the halocline (making a 96% contribution to the microphytoplankton). The potentially toxin-producing diatom Pseudo-nitzschia pseudodelicatissima was recorded at abundances greater than 105 cells L−1, together with Thalassionema frauenfeldii, as well as the dinoflagellates Prorocentrum micans and the potentially harmful P. minimum. The higher values of phytoplankton biomass and the dominance of phytoplankton species or groups with preferences for nutrient-enriched conditions appear to be consistent with the oligo-mesotrophic status of this specific ecosystem.
Źródło:
Oceanologia; 2012, 54, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany składu gatunkowego i struktury syntaksonomicznej zespolu Phyllitido-Aceretum Moor 1952 na Roztoczu Ukraińskim
Changes of species composition and syntaxonomic structure of association Phyllitido-Aceretum Moor 1952 in the Ukrainian part of Roztocze
Autorzy:
Soroka, M.
Wozniak, A.
Powiązania:
https://bibliotekanauki.pl/articles/791608.pdf
Data publikacji:
2017
Wydawca:
Wyższa Szkoła Zarządzania Środowiskiem w Tucholi
Tematy:
lasy jaworowe
zespol Phyllitido-Aceretum
sklad gatunkowy
struktura syntaksonomiczna
Roztocze [geogr.]
forest
sycamore
species composition
composition change
syntaxonomic structure
Phyllitido-Aceretum association
Ukraine
Roztocze macroregion
Źródło:
Zarządzanie Ochroną Przyrody w Lasach; 2017, 11
2081-1438
2391-4106
Pojawia się w:
Zarządzanie Ochroną Przyrody w Lasach
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamika i główne kierunki zmian w drzewostanach zagospodarowanej części Puszczy Białowieskiej
Dynamics and main direction of change in forest stands constituting the managed part of Bialowieza Forest
Autorzy:
Bruchwald, A.
Dmyterko, E.
Brzeziecki, B.
Powiązania:
https://bibliotekanauki.pl/articles/985942.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Bialowieska
drzewostany gospodarcze
dynamika drzewostanu
siedliska lesne
struktura drzewostanu
sklad gatunkowy
struktura wiekowa
miazszosc drzewostanow
przyrost miazszosci
abiotic and biotic threats
forest age structure
low−productivity stands
stand productivity
stand volume
stand stability
species composition
wind risk model
Opis:
The paper describes current (in years 2007−2017) changes of basic parameters of forest stands that constitute the managed part of Białowieża Forest (ca. 53,000 ha), divided into three forest districts: Białowieża (12,600 ha), Hajnówka (19,700 ha) and Browsk (20,400 ha). The investigated tree stands represent different phases of ecological succession, modified by silvicultural treatments and other human activities. The course of the succession processes is varied, depending, first of all, on local site conditions, consisting mainly of fresh sites (ca. 60%) – particularly fresh broadleaved forest, and encompassing exceptionally high fraction of wet and swamp sites (40%) – especially wet broadleaved forest site type. Most stands represent the intermediate, highly productive phase of succession, with spruce and oak as the dominant tree species. In particular, such stands are common in Białowieża and Hajnówka forest districts. Recently, the share of the mentioned stands is declining, most intensely in the Browsk Forest District. In 2017 alone, 430 ha of highly productive forest stands disappeared from the Białowieża Forest. The process of decay involved mixed stands; besides of spruces which were killed by a current bark beetle infestation, also many oaks, pines, birches, alders as well as rare and valuable minor tree species (such as ashes and maples) died. Dying spruce and, more often, oak stands are often replaced by low−productive hornbeam trees, occupying earlier lower stand strata in such stands. The resulting hornbeam stands are often distinguished by low crown closure and low productivity. Tree stands occurring in the Białowieża Forest are among the most endangered by wind damage stands in Poland. It means that in case of strong winds, several trees will be broken and/or uprooted. The intensity of such phenomena will be further increased by the high tree volume of stands as well as by the presence of many gaps in forest canopy, caused by a massive mortality of spruce trees. In general, one may expect that in the nearest future many stands occurring in the Białowieża Forest, built by different tree species, will be subject to a massive decay. The list of factors contributing to this process is long and involves, among other things, recurring droughts during the growing season, unfavorable changes in ground water table and increased frequency of strong winds. All these factors negatively influence the health status of trees, which further favours the development of parasitic fungi and insects. In consequence, there is a high probability that many areas in the Białowieża Forest will, for a long time, retain a treeless character and/or will be occupied by low−productive and single species hornbeam stands.
Źródło:
Sylwan; 2018, 162, 11; 897-906
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany zachodzące w lasach Ziemi Kłodzkiej w latach 2001-2017
Changes in the forests of the Kłodzko Region in years 2001-2017
Autorzy:
Dmyterko, E.
Bruchwald, A.
Powiązania:
https://bibliotekanauki.pl/articles/985721.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Ziemia Klodzka
lasy
sklad gatunkowy
zmiany skladu gatunkowego
klasy wieku
struktura drzewostanu
pozyskiwanie drewna
zlomy
wykroty
posusz
miazszosc surowca drzewnego
zmiany w drzewostanach
dynamika zmian
zagrozenia drzewostanow
lata 2001-2017
species composition
stand age structure
timber harvest
damage caused by wind and drought
stand
growth model
Opis:
The aim of the study was to assess the changes occurring in the forests of the Kłodzko Region in the recent period (2001−2017), with particular emphasis on the species composition of the stands, their share in age classes and the structure of harvested timber, including live trees, deadwood, wind−broken and wind−fallen trees. The Kłodzko Region located in the Sudety Mountains (SW Poland) covers the forests of four forest districts: Lądek−Zdrój, Międzylesie, Bystrzyca Kłodzka and Zdroje. The declining share of spruce stands (from 83.5% in 2001 to 75.5% in 2017) and the increasing share of beech and larch as well as sycamore stands indicate that these forests are systematically rebuilt. The average age of the stands is very high (81 years). The share of young (<20 years old ) stands is low (only 5%), while those older than 100 years constitute about 35%. The 21st century saw a serious damage to the investigated forests caused by frequent strong winds and long−lasting droughts in the growing seasons. The three hurricanes that took place in the analysed period were the cause of the removal of 1.1 million m3 of timber in the form of wind−broken and wind−fallen trees. The drought in the growing season in 2015 resulted in the salvage harvest of deadwood with a total volume of 1.6 million m3, which corresponds to the volume of four annual allowable cuts determined for the undisturbed growth conditions of trees in the area under research. Using the wind damage risk model, the threat measure Ms reaching a value of above 40 was calculated for the forests of the Kłodzko Region, which are currently among the most threatened in Poland. This threat results mainly from the high share of spruce stands in older age classes with high average height and gaps after previous hurricanes as well as from a large area of stands located at high elevations.
Źródło:
Sylwan; 2019, 163, 08; 675-684
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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