Application of cartographic sources, satellite imagery Landsat 7ETM+ and GIS technology to spatial analysis of windthrows in Bory Tucholskie Forest

The spatial distribution of wind-induced damages was analysed in the forest complex of Komorza, situated in the Woziwoda Forest Inspectorate, the region of Bory Tucholskie Forest, northern Poland. The discussed damages were caused by a windstorm on the 22 nd of June 2000 in the forest fragment neighbouring agricultural grounds. The present study aimed at answering two questions: 1 does closer location of forest in relation to field-forest borderline increase damages in the standing timber? 2 – do windinduced damages occur more often and are more severe in the secondary forests restored on the formerly arable lands than in the forests, the development of which was not interrupted by temporary agricultural land use after cutting of trees? In order to define changes in forest and farming grounds in the study area, and as well as to identify secondary forests, old and temporary topographic maps were used, forest economic maps and satellite image Landsat 7ETM+ dated year 2000. Information derived from the above sources and also from the forest stock-taking and direct field measurements carried out with application of GPS receiver were organised in the geographic information system. Statistical analysis conducted according to GIS technology with application of computer programs: MicroStation/Bentley, ESRI ArcView3.2 and Idrisi32, proved that factors like the neighbourhood of large non-forested areas and the temporary use of forest soils for farming purposes do indeed increase range and frequency of damages caused by strong wind in the canopy of forest ecosystems

The use of satellite data and the System of National Forests in the study of spatial distribution and assessment of damages caused by wind storms in forests of chosen areas of Northern Poland

The study presents the Geographic Information System created to analyse spatial distribution of wind-induced damages in forest stands of the Tuchola Forest, northern Poland, and in the vicinity of Toruń. It was used in several forest complexes mainly on the territory of the following Forest Districts in the Tuchola Forest: Woziwoda, Przymuszewo and Czersk, as well as in the Bory Tucholskie National Park. The following Forest Districts were analyzed in the vicinity of Toruń: Gniewkowo, Golub-Dobrzyń, Dobrzejewice and Toruń. The damages in Tuchola Forest were caused mainly by hurricanes in 26th of December 1999 and 22nd of June 2000. The dates of hurricanes caused the largest damages in the vicinity of Toruń were 17th of July 2001 and 28th of October 2002. This work aimed at answering three questions: 1 – Does nearer location of a forest toward field-forest borderline increases the extent of damages? 2 – Does wind-induced damages occur more often and are greater in secondary forests regenerated on formerly arable lands than in forests of which development was not interrupted by temporary soil exploitation for farming purposes after cutting down the trees? 3 – What influence has the geomorphology on the intensity and extent of wind-induced damages? Can anthropogenic changes in orography of terrain connected with road buildings be a factor, which increases probability of wind damages in the forest complex? In order to define changes in forest and agricultural acreage in the study area, as well as to identify secondary forests, old and contemporary topographic maps were applied together with forest economic maps, satellite imageries Landsat 7ETM+ from the year 2000 and IKONOS dated 2003. Information coming from those sources as well as from the forest inventory and from the direct field measurements carried out with the GPS receiver was compiled in the Geographic Information System. The statistical analysis performed in the GIS technology using the programs MicroStation/Bentley, ESRI ArcView3.2 and Idrisi 32 proved that factors like vicinity of large deforested areas as big agricultural areas or big lakes inside forest complex and temporary exploitation of forest soils for farming purposes indeed increase the extent and frequency of damages caused by strong wind in the canopy of forest ecosystems. Changes in orography of area around building site of junction on motorway A1, were a factor which caused appearance of 2-5 ha total treefalls in the adjoining forests. The analyses conducted in GIS and remote sensing technology also indicated that losses in forest area, as well as the canopy of overstory, significantly modify the spatial pattern of the forest landscape.The study presents the Geographic Information System created to analyse spatial distribution of wind-induced damages in forest stands of the Tuchola Forest, northern Poland, and in the vicinity of Toruń. It was used in several forest complexes mainly on the territory of the following Forest Districts in the Tuchola Forest: Woziwoda, Przymuszewo and Czersk, as well as in the Bory Tucholskie National Park. The following Forest Districts were analyzed in the vicinity of Toruń: Gniewkowo, Golub-Dobrzyń, Dobrzejewice and Toruń. The damages in Tuchola Forest were caused mainly by hurricanes in 26th of December 1999 and 22nd of June 2000. The dates of hurricanes caused the largest damages in the vicinity of Toruń were 17th of July 2001 and 28th of October 2002

Rozmieszczenie przestrzenne i wielkość szkód spowodowanych przez wiatr w lasach wybranych obszarów Pomorza

The study presents the Geographic Information System created to analyse spatial distribution of wind-induced damages in forest stands of the Tuchola Forest, northern Poland. It was used in several forest complexes mainly on the territory of the following Forest Districts in the Tuchola Forest: Woziwoda, Przymuszewo and Czersk, as well as in the Bory Tucholskie National Park.. The damages in Tuchola Forest were caused mainly by hurricanes in 26th of December 1999 and 22nd of June 2000. This work aimed at answering three questions: 1 – Does nearer location of a forest toward field-forest borderline increases the extent of damages? 2 – Does wind-induced damages occur more often and are greater in secondary forests regenerated on formerly arable lands than in forests of which development was not interrupted by temporary soil exploitation for farming purposes after cutting down the trees? 3 – What influence has the geomorphology on the intensity and extent of wind-induced damages? In order to define changes in forest and agricultural acreage in the study area, as well as to identify secondary forests, old and contemporary topographic maps were applied together with forest economic maps, satellite imageries Landsat 7ETM+ from the year 2000 and IKONOS dated 2003. Information coming from those sources as well as from the forest inventory and from the direct field measurements carried out with the GPS receiver was compiled in the Geographic Information System. The statistical analysis performed in the GIS technology using the programs MicroStation/Bentley, ESRI ArcView3.2 and Idrisi 32 proved that factors like vicinity of large deforested areas as big agricultural areas or big lakes inside forest complex and temporary exploitation of forest soils for farming purposes indeed increase the extent and frequency of damages caused by strong wind in the canopy of forest ecosystems. The analyses conducted in GIS and remote sensing technology also indicated that losses in forest area, as well as the canopy of overstory, significantly modify the spatial pattern of the forest landscape

Past, current and potential resources of carbon and above-ground plant biomass in the landscape with heaths in some selected areas of the Tuchola Forest

Applying the GIS technologies, historical and contemporary cartographic materials, data coming from the forest inventory and indices of biomass state, the total biomass and biomass for individual layers of forest and non-forest phytocoenoses, the real and potential biomass was assessed, as well as current and potential carbon resources in that biomass in four nature objects. The investigated objects were characterized by different spatial size, as well as by different intensity of human economic activities and different status of nature conservation. Those were: the Tuchola Forest National Park, the Zaborski Landscape Park, as well as the areas of the so-called (forest) demesne of Zabory and the (field) demesne of Tuchola in the former District (Starosty) of Tuchola. In the case of both demesnes, the biomass state was assessed, as well as the extent of its displacement caused by economic human activities, both nowadays and in the past, i.e. for the year 1796 and 2008. The smallest difference in the state of potential and actual biomass was recorded in the National Park. The loss here amounted to 28.44%. The biggest differences occurred in the field demesne in 1796. The loss here reached 76.47%. It was also observed that nowadays the loss slightly decreased, reaching the level of 73.97%. In the demesne of Zabory, the increase of biomass state was considerably higher during the discussed period. In 1796, when heaths and poor xerothermic meadows covered relatively large areas and were exploited as sheep’s grazing lands, the biomass loss amounted here to 69.32% and in 2008 to 51.87%. The increase of biomass state and at the same time the reduction in biomass losses, calculated in relation to the potential, was brought here about mainly by establishing the Prussian Forest Inspectorate Zwangshof in 1890 and by afforestation of agricultural and fallow lands, which was done by Polish forest inspectorates in the 20th century, particularly during several years after the 2nd World War

Porównanie struktury krajobrazu na obszarach intensywnej i ekologicznie zrównoważonej gospodarki leśnej

Zastosowano technologię GIS i metody teledetekcji satelitarnej do oceny i porównań znormalizowanego wskaźnika wegetacji (NDVI), różnorodności i fragmentacji dwóch obszarów leśnych o różnym użytkowaniu w XIX wieku i różnej intensywności pozyskiwania drewna w ostatnich latach. Oba kompleksy leśne zlokalizowane są w Zaborskim Parku Krajobrazowym w województwie pomorskim. Pierwsze stanowisko (M) obejmuje lasy odtworzone w końcu XIX stulecia poprzez nasadzenia sosny na byłych pastwiskach i gruntach ornych. W wyniku intensywnego użytkowania lasów znaczną część terenu zajmują zręby i kilkunastoletnie uprawy sosnowe. Drugie stanowisko (P) obejmuje teren leśny w przeszłości nie użytkowany rolniczo, na którym od kilkunastu lat ograniczono pozyskiwanie drewna, a w 1996 roku utworzono Park Narodowy Bory Tucholskie. Strukturę krajobrazu porównano na pięciu powierzchniach badawczych (około 150 ha lub 500 ha każda) na stanowisku M i czterech powierzchniach o podobnych rozmiarach na stanowisku P. W analizie użyto zdjęcie satelitarne z 28 lipca 1990 roku oraz program Idrisi 32. Stwierdzono, że powierzchnie na stanowisku M charakteryzują się niższymi wartościami NDVI, ale wyższą różnorodnością i fragmentacją, niż powierzchnie zlokalizowane na obszarze dzisiejszego parku narodowego. Znaczne różnice w strukturze krajobrazu na stanowisku obejmującym lasy intensywnie użytkowane i na obszarze lasów o ograniczonym pozyskiwaniu drewna wykazano też metodami klasyfikacji i ordynacji numerycznej.GIS and remote sensing technology have been used to compare Normalized Difference Vegetation Index (NDVI), diversity and fragmentation of two forest complexes different each from the other in the structure of land use in the 19th century and intensively of timber exploitation in the recent several years. Both complexes have been located in Zabory Landscape Park in Pomerania Province. The first site M has been comprised secondary forests restored by introduction of pine seedlings on former poor seep pastures and arable lands. Due to intensive timber exploitation a big part of those area has been occupied by clear-cuttings and few-year-old pine plantations apart from the oldest pine forests. The second site P has been forest complex where the timber exploitation was significantly reduced since the middle of eighties. The structure of landscape in the first site has been assessed on the basis of five sample plots about 150 or 500 hectares. Four plots of similar size have been chosen in the site P. The Landsat TM imagery from 28 July 1990 and Idrisi 32 software have been used in analysis. It results from the calculations that landscape with intensively exploited forests on former agricultural soils has been characterised by lower values of NDVI and higher values of diversity and fragmentation in comparison to those with sustainable forest management. Significant differences in the structure of landscapes have also been clearly expressed by the methods of numerical classification and ordination

The variability processing and analysis of the Gaia mission

We present the variability processing and analysis that is foreseen for the Gaia mission within Coordination Unit 7 (CU7) of the Gaia Data Processing and Analysis Consortium (DPAC). A top level description of the tasks is given.Comment: 4 pages, 1 figure. To be published in the proceedings of the GREAT-ITN conference "The Milky Way Unravelled by Gaia: GREAT Science from the Gaia Data Releases", 1-5 December 2014, University of Barcelona, Spain, EAS Publications Series, eds Nicholas Walton, Francesca Figueras, and Caroline Soubira

Pulsating star research and the Gaia revolution

In this article we present an overview of the ESA Gaia mission and of the unprecedented impact that Gaia will have on the field of variable star research. We summarise the contents and impact of the first Gaia data release on the description of variability phenomena, with particular emphasis on pulsating star research. The Tycho-Gaia astrometric solution, although limited to 2.1 million stars, has been used in many studies related to pulsating stars. Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series have been released. Finally we present the plans for the ongoing study of variable phenomena with Gaia and highlight some of the possible impacts of the second data release on variable, and specifically, pulsating stars.Comment: 12 pages, 4 figures, proceedings for the 22nd Los Alamos Stellar Pulsation Conference Series Meeting "Wide field variability surveys: a 21st-century perspective", held in San Pedro de Atacama, Chile, Nov. 28 - Dec. 2, 201

A comparative study of four significance measures for periodicity detection in astronomical surveys

We study the problem of periodicity detection in massive data sets of photometric or radial velocity time series, as presented by ESA's Gaia mission. Periodicity detection hinges on the estimation of the false alarm probability of the extremum of the periodogram of the time series. We consider the problem of its estimation with two main issues in mind. First, for a given number of observations and signal-to-noise ratio, the rate of correct periodicity detections should be constant for all realized cadences of observations regardless of the observational time patterns, in order to avoid sky biases that are difficult to assess. Secondly, the computational loads should be kept feasible even for millions of time series. Using the Gaia case, we compare the FM method of Paltani and Schwarzenberg-Czerny, the Baluev method and the GEV method of Süveges, as well as a method for the direct estimation of a threshold. Three methods involve some unknown parameters, which are obtained by fitting a regression-type predictive model using easily obtainable covariates derived from observational time series. We conclude that the GEV and the Baluev methods both provide good solutions to the issues posed by a large-scale processing. The first of these yields the best scientific quality at the price of some moderately costly pre-processing. When this pre-processing is impossible for some reason (e.g. the computational costs are prohibitive or good regression models cannot be constructed), the Baluev method provides a computationally inexpensive alternative with slight biases in regions where time samplings exhibit strong aliase