Wyniki wyszukiwania - Biblioteka Nauki

1

Tempo dorastania świerka do przekroju pierśnicowego w drzewostanach świerkowo-sosnowych północno-wschodniej Polski

100%

Zybura H.

|

nr 11

2

Wpływ drzewostanu osłaniającego na dynamikę odnowień podokapowych świerka w drzewostanach z udziałem sosny i świerka w północno-wschodniej części Polski

100%

Zybura H.

|

nr 09-10

3

Relation of the crown length of pine trees to the age and site quality of stand and to the biosocial structure of trees

100%

Zybura H.

Annals of Warsaw Agricultural University. Forestry and Wood Technology

|

1988

|

tom 36

4

Height and height variability of trees in a natural forest

100%

Zybura H.

|

tom 50

5

Mozliwosc zastosowania swierka do realizacji celu hodowlanego na terenie krain Baltyckiej i Mazursko-Podlaskiej

100%

Zybura H.

Prace Instytutu Badawczego Leśnictwa. Seria B

|

1993

|

tom 15

193-200

6

Tempo wzrostu wysokości odnowień podokapowych świerka w północno-wschodniej części Polski

75%

Zybura H.

Sylwan

|

1982

|

tom 126

|

nr 01-03

7

The effect of soil preparation on growth and quality of forest plantations established on abandoned arable grounds

63%

Hamera A. , Zybura H.

|

tom 60

8

Cechy biometryczne podrostów dębowych pochodzenia naturalnego rosnących pod osłoną drzewostanów sosnowych

63%

Zybura H. , Pewniak B.

|

nr 06

EN

The objectives of the study was to investigate and compare the characteristics of oak advance−growth of various age present under Scots pine canopy and growing on the mesic mixed coniferous (BMśw) or mesic mixed deciduous (LMśw) forest site types. The study was conducted in Kolumna Forest District (central Poland) in 21 Scots pine stands ca. 90 years of age, and with a well−developed oak advance−growth. The study sites were divided into 4 groups depending on the age of oak: 15, 20, 25 or 30−years−old. The empirical data concerned trees frequency (per unit area), average breast height diameter, height and basal area. The dependence of these characteristics on type of the main stand and advance−growth was then determined by statistical analysis. Above all, an attempt was made to determine the impact of forest site type conditions on the characteristics of oaks advance−growth. Results show that oaks are present at the density that makes the possibility of the advance−growth development into the stand real. Trees in the upper storey are found to exert a great influence on the silvicultural value of advance−growth trees. In particular, the density of trees in the main stand is a feature found to affect greatly the layer of oak advance−growth.

9

Wpływ drzewostanu sosnowego na tempo wzrostu wysokości buka w dolnym piętrze

63%

Bernacki E. , Zybura H.

|

tom 134

|

nr 02

10

Produkcja siewek drzew iglastych w namiocie foliowym na podłożach organicznych zaopatrywanych podsiąkowo w wodę i składniki pokarmowe

63%

Gunia S. , Zybura H.

Sylwan

|

1983

|

tom 127

|

nr 05

11

Growth, field survival and certain morphological characteristics of Scots pine (Pinus silvestris L.) plants of Polish and foreign provenances

63%

Gunia S. , Zybura H.

Annals of Warsaw Agricultural University. Forestry and Wood Technology

|

1988

|

tom 36

12

The d. b. h. growth of beech in the lower storey of pine stands

63%

Bernadzki E. , Zybura H.

|

tom 42

13

Wykorzystanie dolnych warstw drzewostanu w planowaniu hodowlanym

63%

Zybura H. , Pewniak B.

Sylwan

|

2016

|

tom 160

|

nr 10

EN

Currently observed climate change creates favourable conditions for the development of not only deciduous species (oak and beech), but also some coniferous (e.g. fir). In the Scots pine stands growing on fertile forest site types one can observe the dynamic development of the under−canopy layers composed of those species. Oak or beech saplings are often characterized by good silvicultural value. Also silver fir creates a well−developed cover under Scots pine trees. Beech and fir as the most shade−tolerant tree species are able to handle the conditions under Scots pine. They can grow for a long time under the cover without damage to their height or diameter growth. Especially, a dynamic growth of oaks can often be observed on fresh mixed coniferous and fresh mixed broadleaved habitats. Oak layers in Scots pine stands are generally created in the way of natural regeneration with remarkable contribution of the jays, which spread the seeds even at considerable distances from the old trees. The corresponding intensity of thinnings supports to shape the proper silvicultural value of such under−canopy storeys. Observations on growth of such stand layers in the Scots pine stands in eastern and central Poland consider the desirability of including them in the next generation of stands. Their presence contributes to improvement of the biological stability of the stands, and also leads to increased productivity. By implementing to the forest practice the model of semi−natural silviculture, one wants to consider the possibility of using the saplings currently existing under the Scots pine as a component of the future stand. Knowledge about the silvicultural value and the impact on growth of lower layers will enable to develop the principles of proper cultivation of the multi−storey stands.

14

Height of half-sib Norway spruce (Picea abies L.) Karst.) families of Polish lowland and mountain provenances during first years in plantation

63%

Gunia S. , Zybura H.

Annals of Warsaw Agricultural University. Forestry and Wood Technology

|

1988

|

tom 36

15

Zmiana liczby drzew z wiekiem w drzewostanach sosnowych jako podstawa do oceny możliwości wyboru drzew dorodnych

63%

Zybura B. , Zybura H.

|

nr 5

16

Tempo wzrostu wysokości buka w dolnym piętrze drzewostanów sosnowych

63%

Bernadzki E. , Zybura H.

Sylwan

|

1989

|

tom 133

|

nr 05

17

Sosna zwyczajna (Pinus sylvestris L.) pochodzeń europejskich na uprawie porównawczej w Lasach Doświadczalnych SGGW-AR

63%

Gunia S. , Zybura H.

Sylwan

|

1989

|

tom 133

|

nr 11-12

18

Cechy jakościowe podrostów dębowych rosnących pod osłoną drzewostanów sosnowych

51%

Aleksandrowicz-Trzcinska M. , Pewniak B. , Zybura H.

|

tom 162

|

nr 04

EN

Scots pine stands in central Poland are now seen to be experiencing dynamic development of lower layers formed by oaks. The under−canopy natural renewal taking place in this way is sometimes characterised by good silvicultural quality, and could therefore be taken advantage of in the process of stand conversion. The study assess the quality of existing undergrowth layers of oak present in older stands of Scots pine, most especially from the point of view of their suitability for subjection to further silvicultural measures. The research material was collected in 10 objects where site type was classified as mesic mixed coniferous site type (BMśw) as well as in 11 ones with mesic mixed broadleaved forest (LMśw) site type. In each site type, 2 or 3 stands were selected to typify undergrowth layers aged 15, 20, 25 or 30 years. Assessment of oak undergrowth trees was made on the basis of 4−point scale in case of trunk or crown quality and vitality, and on a 3−point scale when vitality and the development trend were concerned. Next we selected the trees with future potential characterised by the highest quality from the point of view of all studied traits. A further determination concerned the influence on the traits in these best trees of the oak understorey that was exerted by biometric features of both the sheltering Scots pine stand and the undergrowth itself. The studied undergrowth oaks are of either very good or good quality. Around 90% of these young trees could be assigned to 1st or 2nd quality class with the respect of all of analysed traits. Furthermore, fertility of the site type was found not to have any influence on the quality of the young oaks. However, where the number of trees identified as having future potential is concerned, influence was demonstrated for density of trees in both stand and the undergrowth layer, as well as their height, breast−height diameter and basal area. Oaks forming the lower layer beneath Scots pine stands are thus characterised by good quality and growth trends, to the extent that this suggests allowing further growth to take place, with inclusion within the main stand or next generation.

19

Wpływ sposobu przygotowania gleby na cechy odnowienia naturalnego sosny zwyczajnej (Pinus sylvestris L.) w Nadleśnictwie Spychowo

51%

Aleksandrowicz-Trzcinska M. , Drozdowski S. , Ligocki M. , Zybura H.

|

nr 03

EN

Mechanical site preparation is recommended to create optimum conditions for seed germination and seedling growth in a clear−cut area. Lack of soil scarification or less−intense methods may be more suitable from an environmental point of view, but can result in a failure to obtain natural regeneration. This study compared the effects of three mechanical site preparation methods (SPM) characterized by different levels of soil scarification (i.e. double mould−board forest plough (LPz), active plough (PA) or forest mill (FL)), as well as a control variant without mechanical site preparation, on height, density, spatial distribution and survival among naturally regenerating Scots pines (Pinus sylvestris L.) in the first 2 years of growth in a clear−cut area of NE Poland. The experiment was based around a four−block randomized block design involving the four variants. Seedling height was measured at the end of the first and second growing seasons, with measurements performed on 8 meter−wide transects extending across the entire width of the cleat−cut. We found no effect of SPM on seedling height, though the density of seedlings regenerating naturally was found to be dependent. After two years, the highest density was achieved in the PA variant (8.1 seedlings/m²) and the FL variant (7.0 seedlings/m²). A significantly lower density characterized the LPz variant (5.1 seedlings/m²) and the lowest of all the variant without soil scarification (3.2 seedlings/m²). The most homogeneous natural regeneration was achieved following the use of PA (2.6% of 1 m² plots without seedlings after two growing seasons), while the least homogeneous was the variant without soil scarification (22.4% of 1 m² plots). Survival of pines after the second growing seasons was quite high (over 80%), and did not differ significantly depending on the SPM. Our research therefore confirmed that, in the absence of mechanical site preparation, natural regeneration of sufficient density and homogeneity cannot be obtained. The best natural regeneration was obtained on sites prepared with PA, and FL scarification being only slightly less favorable. The low density and uneven distribution of seedlings on the soil prepared with LPz was a surprising result. The probable reason for this lay in the high precipitation in the first growing season. On one hand, this provided very good moisture conditions for seed germination and seedling growth on a substrate with high porosity in the PA and FL variants, but on the other the high bulk density of mineral soil in the LPz variant led to oxygen deficit.

20

Odnowienie naturalne drzew w Puszczy Białowieskiej

51%

Brzeziecki B. , Andrzejczyk T. , Zybura H.

|

tom 162

|

nr 11

EN

Since several years already, a massive infestation of bark beetle has taken place in the Białowieża Forest, decimating a local Norway spruce population. In consequence, many open areas appeared, practically deprived of trees and other forest vegetation. The existence of such areas has a very negative impact on multiple values of the Białowieża Forest: natural, social, economical and landscape−aesthetic values. The local forest administration prepared a strategy aimed at active restoration of diverse woodland communities typical for the Białowieża Forest in all places, where bark beetle infestation wiped up the spruce stands. Those plans were criticized by representatives of the environmental organizations who blamed the foresters for transforming the Białowieża Forest into ‘plantation’ and claiming that such measures are inconsistent with the existing forest management and protection plan. The postulate of environmentalists is that the recovery of woodland communities should proceed completely naturally. Taking into account the above mentioned controversies, in this paper we examine the issue of natural regeneration in the Białowieża Forest in detail. In particular, we try to determine to which extent this method of forest reproduction enables re−establishment of compositionally diverse woodland communities, distinguished by a high level of biological diversity and able to provide a wide range of commodities and benefits important for today’s society. Based on an extensive literature review we show that a combination of different (abiotic and biotic) factors, influencing establishment and subsequent growth of seedlings and saplings in the Białowieża Forest has long been strongly unfavorable for many tree species. In this regard, one should particularly emphasize the negative role of large herbivores, especially red deer, which is present in the Białowieża Forest since the end of 19 th century, when it became a private hunting ground for Russian tzars. The devastating effect of deer browsing on natural regeneration is a well−documented phenomenon and widely recognized problem in the forestry practice. The fencing of young forest generation against game pressure is an indispensable measure, needed to secure the continuous existence of several tree species (first of all those palatable and vulnerable to browsing). Very strong arguments for an active approach to the described problem delivers also a long−term study on natural forest dynamics conducted since 1936. It shows that under conditions of strict protection the regeneration capacity of the Białowieża tree species is very variable. These differences lead to the compositional simplification and impoverishment of many tree stands, with numerous negative consequences for local biodiversity. We underline that an active management strategy is a basic prerequisite for maintaining a diverse character of the Białowieża stands and their ability to provid.