Temat: trees - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Oliwka europejska (Olea europaea) – najdłużej żyjący organizm w śródziemnomorskiej Europie
European olive (Olea europaea) – the longest living organism in Mediterranean Europe
Autorzy:: Boratyński, Adam
Boratyńska, Krystyna
Borkowski, Krzysztof
Tematy:: olive trees
monumental trees
Mediterranean basin; Pokaż więcej
Data publikacji:: 2021-04-27
Powiązania:: https://bibliotekanauki.pl/articles/1196168.pdf Link otwiera się w nowym oknie
Źródło:: Rocznik Polskiego Towarzystwa Dendrologicznego; 2020, 68; 11-33
2080-4164
2300-8326
Pojawia się w:: Rocznik Polskiego Towarzystwa Dendrologicznego
Opis:: Olea europaea is the most emblematic tree of the Mediterranean region. It has been cultivated for about 6000 years for its fruit, oil, wood, and for medicinal and cultural purposes. The research data concerns the monumental olive trees in the region. The oldest and biggest known trees are in Lebanon, Israel, Greece, Albania and Italy. The oldest of those, ‘Sisters of Noahʼ (Lebanon) are believed to be 5000–6000 years old. The most numerous groups of monumental olives were reported from Apulia in Italy and Albania. The oldest and biggest olive trees could be remnants of ancient plantations from the Hellenic and Roman times, but this hypothesis should be confirmed in a detailed study.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: On Independent [1, 2]-Sets in Trees
Autorzy:: Aleid, Sahar A.
Cáceres, José
Puertas, María Luz
Tematy:: domination
independence
spanning trees
excellent trees; Pokaż więcej
Data publikacji:: 2018-08-01
Powiązania:: https://bibliotekanauki.pl/articles/31342284.pdf Link otwiera się w nowym oknie
Źródło:: Discussiones Mathematicae Graph Theory; 2018, 38, 3; 645-660
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Opis:: An [1, k]-set S in a graph G is a dominating set such that every vertex not in S has at most k neighbors in it. If the additional requirement that the set must be independent is added, the existence of such sets is not guaranteed in every graph. In this paper we solve some problems previously posed by other authors about independent [1, 2]-sets. We provide a necessary condition for a graph to have an independent [1, 2]-set, in terms of spanning trees, and we prove that this condition is also sufficient for cactus graphs. We follow the concept of excellent tree and characterize the family of trees such that any vertex belongs to some independent [1, 2]-set. Finally, we describe a linear algorithm to decide whether a tree has an independent [1, 2]-set. This algorithm can be easily modified to obtain the cardinality of a smallest independent [1, 2]-set of a tree.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Completely Independent Spanning Trees in (Partial) k-Trees
Autorzy:: Matsushita, Masayoshi
Otachi, Yota
Araki, Toru
Tematy:: completely independent spanning trees
partial k-trees; Pokaż więcej
Data publikacji:: 2015-08-01
Powiązania:: https://bibliotekanauki.pl/articles/31339419.pdf Link otwiera się w nowym oknie
Źródło:: Discussiones Mathematicae Graph Theory; 2015, 35, 3; 427-437
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Opis:: Two spanning trees T1 and T2 of a graph G are completely independent if, for any two vertices u and v, the paths from u to v in T1 and T2 are internally disjoint. For a graph G, we denote the maximum number of pairwise completely independent spanning trees by cist(G). In this paper, we consider cist(G) when G is a partial k-tree. First we show that ⌈k/2⌉ ≤ cist(G) ≤ k − 1 for any k-tree G. Then we show that for any p ∈ {⌈k/2⌉, . . ., k − 1}, there exist infinitely many k-trees G such that cist(G) = p. Finally we consider algorithmic aspects for computing cist(G). Using Courcelle’s theorem, we show that there is a linear-time algorithm that computes cist(G) for a partial k-tree, where k is a fixed constant.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: European silver fir - an alternative for the dying Norway spruce in Bialowieza Forest?
Autorzy:: Marozau, Aleh
Mielcarek, Miłosz
Krok, Grzegorz
Paluch, Rafał
Chilinski, Krzysztof
Tematy:: artificial origin
old trees
adult generation
trees conditions; Pokaż więcej
Data publikacji:: 2021
Powiązania:: https://bibliotekanauki.pl/articles/2041262.pdf Link otwiera się w nowym oknie
Źródło:: Folia Forestalia Polonica. Series A . Forestry; 2021, 63, 2; 150-166
0071-6677
Pojawia się w:: Folia Forestalia Polonica. Series A . Forestry
Opis:: The condition of Norway spruce (Picea abies (L.) Karst) in the Białowieża Forest is categorized as a crisis. It is believed that due to the cooling in the Holocene, the then-relict species of the forest, silver fir (Abies alba Mill.), disappeared from its ecosystems and then spruce appeared. Today’s climate change presents challenges to our civilization, including to forestry. However, there is no information at all about how this affected the silver fir in the Białowieża Forest. In the Polish part of the forest (subcompartment 498 Сi, Białowieża Forest District), for the first time a comprehensive study has been carried out on the condition of mature fir trees planted by man and on their progeny. The results indicate high forestry-taxation indicators of trees, resistance to the abiotic factor and competitiveness. Their constitution corresponds to local environmental conditions. However, the disproportionately small number of adult natural regeneration of old firs indicated some kind of malfunction in the mechanism of natural generational change.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Note: Sharp Upper and Lower Bounds on the Number of Spanning Trees in Cartesian Product of Graphs
Autorzy:: Azarija, Jernej
Tematy:: Cartesian product graphs
spanning trees
number of spanning trees
inequality; Pokaż więcej
Data publikacji:: 2013-09-01
Powiązania:: https://bibliotekanauki.pl/articles/30098147.pdf Link otwiera się w nowym oknie
Źródło:: Discussiones Mathematicae Graph Theory; 2013, 33, 4; 785-790
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Opis:: Let $ G_1 $ and $ G_2 $ be simple graphs and let $ n_1 = |V (G_1)| $, $ m_1 = |E(G_1)| $ , $ n_2 = |V (G_2)|$ and $ m_2 = |E(G_2)|$. In this paper we derive sharp upper and lower bounds for the number of spanning trees $ \tau $ in the Cartesian product $ G_1 \square G_2 $ of $ G_1 $ and $ G_2 $. We show that: $$ \tau (G_1 \square G_2 ) \geq \frac{2(n_1-1)(n_2-1)}{n_1 n_2} (\tau (G_1) n_1 )^\frac{n_2+1}{2} (\tau(G_2)n_2)^\frac{n_1+1}{2} $$ and $$ \tau(G_1 \square G_2 ) \leq \tau (G_1) \tau (G_2) \left[ \frac{2m_1}{n_1-1} + \frac{2m_2}{n_2-1} \right]^{(n_1 - 1)(n_2 -1)} . $$ We also characterize the graphs for which equality holds. As a by-product we derive a formula for the number of spanning trees in $ K_{n_1} \square K_{n_2} $ which turns out to be $ n_1^{n_1-2} n_2^{n_2-2} (n_1 + n_2 )^{(n_1-1)(n_2-1)} $.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Arbitrarily vertex decomposable caterpillars with four or five leaves
Autorzy:: Cichacz, Sylwia
Görlich, Agnieszka
Marczyk, Antoni
Przybyło, Jakub
Woźniak, Mariusz
Tematy:: arbitrarily vertex decomposable graphs
trees
caterpillars
star-like trees; Pokaż więcej
Data publikacji:: 2006
Powiązania:: https://bibliotekanauki.pl/articles/743967.pdf Link otwiera się w nowym oknie
Źródło:: Discussiones Mathematicae Graph Theory; 2006, 26, 2; 291-305
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Opis:: A graph G of order n is called arbitrarily vertex decomposable if for each sequence (a₁,...,aₖ) of positive integers such that a₁+...+aₖ = n there exists a partition (V₁,...,Vₖ) of the vertex set of G such that for each i ∈ {1,...,k}, $V_i$ induces a connected subgraph of G on $a_i$ vertices. D. Barth and H. Fournier showed that if a tree T is arbitrarily vertex decomposable, then T has maximum degree at most 4. In this paper we give a complete characterization of arbitrarily vertex decomposable caterpillars with four leaves. We also describe two families of arbitrarily vertex decomposable trees with maximum degree three or four.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: The Smallest Harmonic Index of Trees with Given Maximum Degree
Autorzy:: Rasi, Reza
Sheikholeslami, Seyed Mahmoud
Tematy:: harmonic index
trees; Pokaż więcej
Data publikacji:: 2018-05-01
Powiązania:: https://bibliotekanauki.pl/articles/31342320.pdf Link otwiera się w nowym oknie
Źródło:: Discussiones Mathematicae Graph Theory; 2018, 38, 2; 499-513
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Opis:: The harmonic index of a graph G, denoted by H(G), is defined as the sum of weights 2/[d(u) + d(v)] over all edges uv of G, where d(u) denotes the degree of a vertex u. In this paper we establish a lower bound on the harmonic index of a tree T.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Extensions of the minimum labelling spanning tree problem
Autorzy:: Cerulli, R.
Fink, A.
Gentili, M.
Voss, S.
Tematy:: network design
metaheuristics
spanning trees
labelling trees
Steiner tree problem; Pokaż więcej
Data publikacji:: 2006
Powiązania:: https://bibliotekanauki.pl/articles/308930.pdf Link otwiera się w nowym oknie
Źródło:: Journal of Telecommunications and Information Technology; 2006, 4; 39-45
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Opis:: In this paper we propose some extensions of the minimum labelling spanning tree problem. The main focus is on the minimum labelling Steiner tree problem: given a graph G with a color (label) assigned to each edge, and a subset Q of the nodes of G (basic vertices), we look for a connected subgraph of G with the minimum number of different colors covering all the basic vertices. The problem has several applications in telecommunication networks, electric networks, multimodal transportation networks, among others, where one aims to ensure connectivity by means of homogeneous connections. Numerical results for several metaheuristics to solve the problem are presented.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Drzewa jako element ryzyka związanego z anomaliami pogodowymi
Trees as a risk related to weather anomalies
Autorzy:: Rosłon-Szeryńska, Edyta
Tematy:: trees in urbanized space
windbreaks and fallen trees
trees and storms
hazard trees
drzewa w przestrzeni zurbanizowanej
wiatrołomy i wykroty
drzewa i wichury
ryzyko ze strony drzew; Pokaż więcej
Data publikacji:: 2023
Powiązania:: https://bibliotekanauki.pl/articles/55993347.pdf Link otwiera się w nowym oknie
Źródło:: Rozwój Regionalny i Polityka Regionalna; 2023, 64; 253-271
2353-1428
Pojawia się w:: Rozwój Regionalny i Polityka Regionalna
Opis:: Drzewa stanowią zasadniczy element zielonej infrastruktury pełniący usługi ekosystemów. Jednak podstawą racjonalnego gospodarowania zadrzewieniem w miastach jest bilans korzyści i strat związany z ich obecnością w przestrzeni zurbanizowanej, zwłaszcza w dobie zmian klimatycznych i wzmagających się anomalii pogodowych. Celem artykułu jest przedstawienie problematyki zagrożenia ze strony drzew w Polsce na tle wybranych krajów Europy i Ameryki. W ramach pracy sporządzono statystyki wypadków i szkód powodowanych przez drzewa podczas wichur w latach 2000–2021. Powstał współczynnik regionalny ryzyka związanego z wiatrołomami i wywrotami. Badania własne udowodniły, że liczba i skutki wypadków w Polsce są na podobnym (niskim) poziomie co na świecie. Należy więc chronić drzewa, dbając o ich stan. Przedstawiono wytyczne do zarządzania ryzykiem. Wyniki badań mają przyczynić się do lepszego gospodarowania drzewami w przestrzeni zurbanizowanej, ale i do poprawy warunków życia człowieka w miastach.
Social awareness of the important role of trees in the natural environment and in the cultural landscape has existed for centuries, but it turns out to be extremely important today, in the era of progressive climate change. The multifaceted natural, social, health, cultural, aesthetic and economic benefits provided by trees, supported by many scientific studies, are converted into monetary values, which allows to effectively use their potential in building comfort and functionality of life in urban areas. For this reason, trees in many countries are considered a national good and the green capital of cities (Szczepanowska, Sitarski 2015), and the concept of “ecosystem services” and “green infrastructure” with trees in the main role is implemented in the spatial policy of territorial units around the world. The benefits of the presence of trees dominate the possible nuisance and losses caused by trees (Rosłon-Szeryńska 2019). Nevertheless, in Poland, one can notice many problems with trees in the space of human life. The main thread is the discussion on the security risk, and the number of decisions authorizing logging is increasing year by year. The threat to safety is currently one of the important reasons for the removal of trees (Krynicki, Witkoś 2016). It is related to the financial liability of the owner of the land for damage caused by the tree in case of negligence in its care and maintenance. The Nature Conservation Act (Journal of Laws of 2021, item 1098) lists trees that threaten the safety of equipment, people or property as well as the safety of road, rail and shipping traffic, and the removal of which requires a permit from the commune without incurring fees. title. However, the lack of a method specifying the criteria of risk assessment contributes to many types of fraud. Identifying the threat and quantifying the risk associated with trees present in the cultural landscape is the basis of a properly functioning tree management system. Knowledge about the frequency and effects of falling and breaking trees allows you to make rational decisions adequate to the scale of the risk. The aim of the article is to present the problem of the threat posed by trees in Poland against the background of selected European and American countries. As part of the work, statistics of accidents and damage caused by trees during storms in the years 2000–2021 were compiled. A regional coefficient for the risk of windbreaks and overturning has been established. Own research proved that the number and effects of accidents in Poland are at a similar (low) level as in the world. Therefore, trees should be protected by taking care of their condition. Risk management guidelines are provided. The results of the research are to contribute to a better management of trees in urban areas, but also to the improvement of human living conditions in cities.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Monument trees in the Kampinos National Park (Central Poland): A review
Autorzy:: Szczepkowski, Andrzej
Tyburski, Łukasz
Sułkowska, Małgorzata
Tematy:: Kampinos Forest
very large trees
venerable trees
natural monument
nature conservation; Pokaż więcej
Data publikacji:: 2020
Powiązania:: https://bibliotekanauki.pl/articles/2041515.pdf Link otwiera się w nowym oknie
Źródło:: Folia Forestalia Polonica. Series A . Forestry; 2020, 62, 3; 210-219
0071-6677
Pojawia się w:: Folia Forestalia Polonica. Series A . Forestry
Opis:: The paper presents the history of the protection of trees with special values, the current state of monument trees and the preliminary description of trees meeting the minimal circumference criteria to be regarded as natural monuments in the Kampinos National Park (KNP). The study was conducted in the years 2017–2019. In the KNP, there are 69 living trees with a status of natural monuments. Most of them are oaks – 56 specimens, Scots pine – 6 specimens, small-leaved lime – 5 specimens and European hornbeam and European ash – 1 specimen each. Among all, 27 trees grow individually and the other 42 grow in 7 groups. About 200 trees were recognised as meeting the minimal circumference criteria to be regarded as natural monuments. The thickest size tree in the KNP is the black poplar with a circumference of 805 cm, growing in the enclave of Ruska Kępa, and the thickest monument tree in the KNP area is Dąb Kobędzy (Kobendza Oak) with a circumference of 582 cm. Almost a half of the living monument trees (34 specimens) are situated in Kampinos Forest District. In Kromnów, there are 20, and in Laski Forest District 15 specimens of monument trees are mapped. Living monument trees were found in 15 (out of 17) forest subdistricts. The highest number of monument trees was found in Rózin Forest Subdistrict (16) and in Wilków Forest Subdistrict (10). The lowest number – one specimen per forest subdistrict – was found in six forest subdistricts (Dąbrówka, Grabina, Janówek, Krzywa Góra, Rybitew and Zamczysko). In total, there are around 300 specimens of natural monuments and trees meeting the minimal circumference criteria to be regarded as natural monuments, which means that there is one tree of this category for each 125 ha surface of the KNP.
Dostawca treści:: Biblioteka Nauki

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