Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Improved methods of classification of multispectral aerial photographs: evaluation of floodplain forests in the inundation area of the Danube

100%

Bucha T., Slavik M.

Folia Forestalia Polonica. Series A . Forestry

|

2013

|

tom 55

|

nr 2

The Gabčíkovo hydroelectric power plant has significantly influenced Danube water regime, thus the condition of floodplain forests in the region. Forest condition has been regularly monitored since 1995 using aerial photos. The subject of this study was to improve the procedure of floodplain forest health evaluation based on digital multispectral aerial images. Firstly, the forest mask was created with overall accuracy 89%, and next, tree health was evaluated using defoliation as health indicator. We applied orthogonal transformation of 4 original bands of multispectral imagery into two-dimensional space. Marginal values of digital numbers (DN) of the first component (New Synthetic Channel – NSC1) were defined by fully foliated willow and poplar. The second component (NSC2) was optimised for damage estimation. Calculated DN values of NSC2 represented a perpendicular distance from the line of DN values of the first component. The distance from the line was proportionate to tree damage extent in a given pixel. We generated linear regression model between pair values of NSC2 and defoliation evaluated for 38 trees in the field, respectively, from aerial photos. A decline prediction resulted in r-square equal 0.86. Finally, we used the model to predict defoliation for each picture element (pixel) of the component NSC2.

2

Tree growing space and acorn production of Quercus robur

100%

Martinik A., Dobrovolny L., Palatova E.

Dendrobiology

|

2014

|

tom 71

Pedunculate oak (Quercus robur L.) is considered the main commercial tree species in conditions of floodplain forests of central Europe. In the Czech Republic clear-cutting silvicultural system represents a prevailing regeneration method of oak stands in floodplain forest. The natural regeneration is limited only in stands and years with sufficient acorn production. We analysed an acorn crop periodicity and an influence of canopy opening to the acorn production in South Moravian floodplain forest, Czech Republic between 2008 and 2011, The acorn crop from trees with different growth spaces in four stand conditions (closed canopy (A), moderate open canopy (B), open canopy (C) and single growing trees (D) with unlimited growth space was analysed. The amount of acorns was determined using seed traps placed under the crowns of sample trees. The average amount of acorns in 2009 and 2011 ranged from 13 (A) to 102 (C)/m2 and from 2 (A) to 124 (D)/m2, respectively. At the same time, a considerable difference was recorded in the fructification of sample trees in the various stand situations. Significant correlations were confirmed between the amount of acorns and crown size (r2 2009=0.27, r2 2011=0.07) of parent trees and their growth space – release area (r2 2009=0.42, r2 2011=0.25) and social area (r2 2009=0.31, r2 2011=0.26). The production of acorns could be affected by establishing conditions for the pedunculate oak with a minimum crown projection area in adult trees of at least 70 m2 and/or with a minimum release area of 300 m2, it means spacing between parent trees about 10 m or 100 trees per 1 ha.

3

Large-scale changes of the forestation in river channel below the dams in Southern African rivers: assessment using the Google Earth Images

84%

Uddin F. M. J., Asaeda T., Rashid M. H.

Polish Journal of Ecology

|

2014

|

tom 62

|

nr 4

According to the results of many studies construction of dams, their decommissioning, and sediment flushing from the reservoir have been associated with vegetation dynamics. However, factors governing the spatial changes of forestation in the floodplain below the dams have not been explored extensively. This study examined the interacting effects of dam, inflow and land-use patterns of catchment areas and other factors on downstream vegetation patterns along the downstream reaches of Southern African Rivers. A total of 105 segments of 15 rivers (16 dams) located in seven Southern African countries were studied. Areas of herbaceous and forest vegetation of river channels below a dam and land-use catchment area patterns were obtained by the Google area calculator and aerial image analysis. Forest development was the highest just below the dams, and the ratio of forest cover decreased with distance from the dam toward the river mouth. Forest coverage ratio was found to decrease with an increase in dyke distance, number as well as of inflows (r = −0.66, P <0.01) and water coverage ratio, and bare land in the river flood plain. However, a principal component analysis (PCA) showed that the proportion of bare land in the catchment area, the dyke distance of the river and the number of inflows or tributaries are the factors most associated with forestation among the studied parameters. Forestation progressively decreased following the entrance of free following tributaries below dams, which appeared to reduce the effects produced by dams on vegetation forestation by causing local deviation. The impact of different land use types, such as agriculture on forestation, was insignificant though in some cases, land use areas cause the forest area reduction.

4

Linking the historical research with the growth simulation model of hardwood floodplain forests

84%

Simon J., Machar I., Bucek A.

Polish Journal of Ecology

|

2014

|

tom 62

|

nr 2

Hardwood floodplain forests of lowland rivers in the temperate zone of Europe represent important refugia for biota in the cultural landscape. Most of these habitats that are in near natural state are included in the system of protected areas and ecological networks. This paper presents the results of an innovative method for the assessment of hardwood floodplain forest management strategy. This method is based on combining the analysis of historical development of the forest ecosystem with the growth simulation model of the forest. The method allows us to understand (explain) the current state of the hardwood floodplain forest ecosystem and to predict its future development taking into account the applied forest management strategy. Application of this method is promising especially in protected areas because it allows us to assess the suitability of the chosen strategy that is included in the protected area management plan. The research was conducted in the area of ‘Bahna’ in Litovelské Pomoraví protected landscape area (Czech Republic). The current management strategy applied on the hardwood floodplain forest ecosystem in the study site is based on a strict non-intervention protection regime. Historical research of the forest ecosystem showed that the studied floodplain forest habitat is a relic of coppice with standards system and thus is the result of intensive forest management in the past. Growth simulation model showed that in the future 40 years the assessed management strategy will not lead to significant changes in the structure or diversity of the tree layer. Considering the conservation objectives of the reserve (maintenance of biodiversity and the present character of the forest ecosystem dominated by ash and oak), the current management plan does not require any significant corrections. The presented results can be applied in discussions about optimal management strategies in protected areas containing hardwood floodplain forest ecosystems, which belong to priority natural habitat types in the Natura 2000 network.

5

Circadian rhythms of ground living spiders: mechanisms of coexistence strategy based on the body size

84%

Krumpalova Z., Tuf I. H.

Polish Journal of Ecology

|

2013

|

tom 61

|

nr 3

Circadian rhythms of activity are one of the many cases of the multidimensional mechanisms of species coexistence. Except of others, the mechanisms of coexistence strategy of spiders involve habitat, seasonal occurrence, food offers and body size of spiders. Circadian rhythm of activity of ground living spiders in floodplain forest and clearcut along the Morava River in the Litovelské Pomoraví Protected Landscape Area (Czech Republic, Central Europe) was studied. Activity of whole community was asymmetrical, diurnal activity was more frequent than nocturnal. Abundant species were analysed closely. Patterns of similarity in syntopic spider groups suggested the body size is significant factor influencing their circadian activity. We found out the predominantly small species achieved bimodal pattern of activity, influenced by the different activity of males and females. Generally we can conclude that spiders smaller than 5 mm were active during late night-morning and spiders bigger than 5 mm were active during afternoon and evening. This pattern was associated with changes of temperature of soil surface – big spiders were active during warmer parts of day. The presented data provide evidence of body-size differences among the spiders enable their coexistence in assemblages.

6

Subfossil pollen spectra of flood-plain forest of Pterocarya pterocarpa in the Alazani Valley [East Georgia]

84%

Stuchlik L., Kvavadze E.

Acta Palaeobotanica

|

1998

|

tom 38

|

nr 1

7

Macrofungi of the Querco-Ulmetum minoris association in the Ostrow Panienski Reserve on the Vistula River [N Poland]

84%

Bujakiewicz A.

Acta Mycologica

|

2001

|

tom 36

|

nr 1

8

Osmotic adaptation of Quercus robur L. under water stress in stands with different tree density - relation with groundwater table

67%

Cater M.

Dendrobiology

|

2011

|

tom 65

Solute accumulation in plant leaves during drought through accumulation of organic compounds is known to compensate turgor loss andpromote higher stomatal conductance at lower water potentials. Recent studies have involved experiments on saplings and younger stands, while evidence of osmotic adjustment in adult pedunculate oak under natural stand conditions on different sites is scarce. Pressure volume curves technique was used to define differences in osmotic potential – water stress adaptation – of 120 year oldped unculate oak trees in two managedforest complexes andin virgin forest remnant. Tree response between the managedstandafter thinning andthe standwithout any silvicultural measures within same forest complex was also compared during summer months in two consecutive (dry and favourable) years with groundwater table. Significant differences were observed in adaptation between forest complexes and during dry (2003) and favourable (2004) years. Osmotic component of thinnedforest was the highest, showing most negative values of stress adjustment. Measured values on all plots responded well to drop in groundwater table, especially in pronounced drought conditions. Such response may be in relation with lower stand density and increased individual space for growth in thinned stand. Adult oaks did not loose their ability to water stress adaptation, in spite of their age and progressively decreasing health conditions.

9

The concept for protection of flood plain forests in the Uroczysko Warta forest district

67%

Kaminski B., Miler A. T., Grajewski S., Okonski B., Schwartz K.

Infrastruktura i Ekologia Terenów Wiejskich

|

2010

|

nr 11

Flood plain forests are the richest and highly picturesque forest ecosystems. Unfortunately, river regulation and flood control contribute to their degradation. In Poland only 0.2% of total area is covered by flood plain forests. The Uroczysko Warta forest district constitutes one of the most important clusters of these sites. The construction of the Jeziorsko reservoir in the middle course of the Warta River has contributed to changes in the river regime (reduced flooding areas and decreased flooding frequency). It seems that the use of simple land improvement systems, i.e. gates, river bars and culverts with flap check valves, may result in the recreation of advantageous hydrological conditions. In such a case storage volume of oxbow lakes would be increased and ground water would be maintained at a higher level over longer periods of time. This study presents a concept for protection of the Uroczysko Warta, thanks to the construction of appropriate engineering infrastructure.

10

Anthropogenic impact on fluvisols in german floodplains. Ecological processes in soils and methods of investigation

67%

Haase D., Neumeister H.

International Agrophysics

|

2001

|

tom 15

|

nr 1

Ograniczanie wyników

Improved methods of classification of multispectral aerial photographs: evaluation of floodplain forests in the inundation area of the Danube

Tree growing space and acorn production of Quercus robur

Large-scale changes of the forestation in river channel below the dams in Southern African rivers: assessment using the Google Earth Images

Linking the historical research with the growth simulation model of hardwood floodplain forests

Circadian rhythms of ground living spiders: mechanisms of coexistence strategy based on the body size

Subfossil pollen spectra of flood-plain forest of Pterocarya pterocarpa in the Alazani Valley [East Georgia]

Macrofungi of the Querco-Ulmetum minoris association in the Ostrow Panienski Reserve on the Vistula River [N Poland]

Osmotic adaptation of Quercus robur L. under water stress in stands with different tree density - relation with groundwater table

The concept for protection of flood plain forests in the Uroczysko Warta forest district

Anthropogenic impact on fluvisols in german floodplains. Ecological processes in soils and methods of investigation