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The European beech is a major component of central European forests, and the eastern limit of its range lies in Poland. However, the Holocene migration of the beech is not yet finished, especially in NE Poland, so the northern distribution of the beech continues to change. The main goal of this study was to determine if the beech will reach its northern limit in the future. The investigation was carried out in 18 beech stands in Poland. To study the status of the health of the trees, circular plots were established in grids of different sizes. The basal beech stand area ranged from 3.7 m² ha⁻¹ to 31.2 m² ha⁻¹. The density of trees exceeded a hundred trees per hectare in most of the plots (61%), and the average degree of defoliation was not greater than 60% in all of the investigated stands. Environmental conditions influenced defoliation of beech trees (Fisher's test, F = 4.0204; P <0.0001). The vitality of the beech trees varied between stands (Kruskal-Walis test, H = 139.7433, P <0.0001) and was rather good in 56% of the study plots. Seedlings and saplings were observed in all of the investigated stands, and they covered from 5 to 39% and 21 to 80% of the study plots, respectively. Spontaneous beech regeneration was widespread and differed from stand to stand as well as within stands in all of the study plots. The number of tall seedlings in most of the study plots (56%) was greater than 10,000 individuals per hectare. The factors limiting beech regeneration were stand density and herb cover, and the number of beech seed trees influenced the quantity of small seedlings. Beech tree density positively influenced the number of small seedlings, and the strength of the correlation was moderate and statistically significant (Pearson correlation, r = 0.349). Beech tree density influenced the vitality of tall and small saplings (Pearson's correlations, r = 0.673 and r = 0.361, respectively). The spontaneous regeneration and strong vitality of seedlings and saplings suggests that beech can create stable stands in the future and that it is an expansive tree species both within its continuous range and at the limit of its distribution. It is quite possible that beech will reach its north-eastern limit in Poland in the future.
Conditions found in cities do not favoure the growth or development of trees. This results from three major factors: 1. the lack of available oxygen around the root system, which is caused by excessive soil compaction. This results in plant suffocation, 2. a shortage or excess of certain macro- and micronutrients, and frequently their inappropriate ratios do not guarantee perfect plant nutrition, 3. a drastic shortage of water available to roots, which leads to drought, as a result leaves prematurely dry up and die. Knowing the most important factors affecting the adequate tree condition it is possible to reduce unfavourable factors to a certain degree in case of new plantings. There are very many such cultivation measures to be applied. Selection of a species and a variety for specific habitat conditions, selection and preparation of an adequate substrate, selection of appropriate nursery material, adopted planting method – these are only some factors determining the future condition of trees, which need to be properly selected prior to tree planting. The second group of cultivation measures is realized already after planting trees in their permanent location. It includes such measures as watering, fertilization, cutting, mulching, aeration and fencing of trees. Some of these cultivation measures and their effect on tree condition are discussed in this study.
Zróżnicowanie genetyczne populacji drzew leśnych jest jednym z kluczowych elementów gwarantujących ich przeżywalność w zmiennych warunkach środowiska. Badanie struktury DNA jest możliwe dzięki zastosowaniu markerów genetycznych DNA jądrowego (m.in. mikrosatelity - SSR) i cytoplazmatycznego (PCR-RFLP, STS), powszechnie stosowanych do określenia zmienności genetycznej osobników, populacji i gatunków. Badaniami objęto drzewostany dębowe i bukowe, położone w różnych regionach Polski. Zdrowotność drzewostanów oceniano na podstawie obserwacji symptomów chorobowych w latach 2004-2006 dla buka i 2004-2005 dla dębu, oraz na podstawie występowania Phytophthora spp.: P. citricola, P. cambivora, P. cinnamomi i P. quercina. Zróżnicowanie genetyczne populacji oceniano na podstawie polimorfizmu DNA chloroplastowego metodą markerów SSR i PCR-RFLP, po czym wyrażano za pomocą frekwencji alleli oraz heterozygotyczności poszczególnych drzewostanów. Na podstawie otrzymanych wyników stwierdzono, że drzewostany o większej zdrowotności charakteryzuje większy stopień zróżnicowania genetycznego. W związku z tym, podatność drzew na wystąpienie zjawisk chorobowych ma silne uwarunkowanie genetycznie.
This paper presents a characteristics of the largest population of European yew Taxus baccata L. in the polish part of the Carpathian mountains. Number of yew individuals was determined along with their spatial distribution, and the chosen features of population were analyzed. Detailed field studies included: measurement of tree height and stem thickness, determination of sex and developmental stage (seedlings, juveniles, mature, senescent) as well as the relationships among them. The health status and vitality of each individual were also evaluated, and a prognosis of population development was made. Taking into account the local growth conditions of the population and the type of management applied in the forests of the Beskid Niski range, some recommendations were matle for the active protection of yew in this region.
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