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
