Recent changes of the timberline and treeline in the Southern Carpathians (Romania). Presented by Marcel Török-Oance at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.

1. Marcel Török-Oance, Rodica Török-Oance,
Alexandru Onaca, Florina Ardelean, Mircea Voiculescu
This work was supported by CNCSIS – UEFISCSU, project number PNII – IDEI 1075/2009
and by CNMP, project number PNII – GEOMORF 32-140/2008.

2. • The most massive and highest part of the
The Southern Carpathians Romanian Carpathians
• 10 % of the mountain areas lies above 2000 m
• The maximum elevation is 2544 m
(Moldoveanu Peak, Făgăraş Mountains)
•The presence of the
vegetation levels:
- the alpine level
(> 2200 m)
- the subalpine level
(from treeline to 2200 m)
- the coniferous forest
level (from 1300-1400 m
to around 1800 m)
- the deciduous forest
level (< 1300-1400 m).
•The Carpathians are a
very old living space
with intense human
activity. The most
important activity which
affect the timberline area
is the grazing.

3. The Southern Carpathians have a temperate mountain climate.
- the mean annual air temperatures vary between 7°C and –2°C above
2100 m (-2.6°C at Omu Peak, 2505m).
-the mean annual precipitations values are between 700 mm and 1200 mm
o
t
C
The variation of the
-1
-1. 5
mean annual air
-2
temperature and of the
-2. 5 mean annual
-3 precipitation at the
-3. 5
Omu meteorogical
-4
station (2505 m),
19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 2 0
ani i
S t . V f . O mu
6 1
- 2
6 2
- 2
6 3
- 2
6 4
- 3
6 5
- 3
6 6
- 2
6 7
- 3
6 8
- 2
6 9
- 3
7 0
- 3
7 1
- 3
7 2
- 2
7 3
- 3
7 4
- 3
7 5
- 2
7 6
- 3
7 7
- 2
7 8
- 3
7 9
- 2
8 0
- 3
8 1
- 3
8 2
- 2
8 3
- 3
8 4
- 3
8 5
- 3
8 6
- 2
8 7
- 4
8 8
- 3
8 9
- 2
9 0
- 2
9 1
- 3
9 2
- 3
9 3
- 2
9 4
- 1
9 5
- 3
9 6
- 3
9 7
- 3
9 8
- 2
9 9
- 2
0 0
- 2
1964-2006 interval
P p ( mm)
1800
1600
1400
1200
1000
800
600
400
200
0
a ni i 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00
St . V f . O mu 127 132 102 105 101 165 115 130 143 159 135 134 157 126 119 129 147 112 103 884 981 678 740 585 404 636 521 652 509 475 102 654 835 961 108 815 944 826 847 440

4. The aim
• to detect the changes of the timberline/treeline using
remote sensing data, old vegetation maps and field data
during the last 50 years
The data
Old maps: 1:20,000 topogrpaphical maps (1930 - 1953 edition)
1:25,000 topographic maps (1980 edition)
Forestry cadastre maps (1:10,000)
Airphotos: black and white airphotos (1956 and 1972)
color airphotos (2005, 2008)
Satelite images: Landsat TM/ETM+ images (1988, 2002 and 2006),
SPOT images (2008)
Field data (including GPS data)

5. Methods
At regional scale:
- the supervised classification of the Landsat images in order to obtain Land
cover maps from different periods.
- the change detection method (Landsat TM/ETM+ scenes)
- the estimation of changes using Land Change Modeler tool (Idrisi Andes
software)
At local scale:
- both visual and GIS analysis based on old and recent cartographic
documents, airphotos and recent high resolution satellite images (SPOT).
-Field data were used:
- to differentiate the training sites (more than 300 points for each satellite
scene)
- for the accuracy assessment of the supervised classification
- to identify the vegetation types, the geomorphological present-day
processes and the human impact on the timberline/treeline

6. The classification of the satellite images
Landsat TM and ETM+ images:
For the Retezat – Godeanu Massif: August 1998- August 2006
For the Făgăraş Massif: August 1996- August 2004
1. The mitigation of the topographic effect - the shadows generated by steep
slopes exaggerate the difference in reflectance information coming from the same
landcover type. Shading is the main problem in using satellite imagery for
classification purposes in high mountain areas.
Mitigation of the topographic effect based on DEM
Landsat image - Band 4 (NIR)
Landsat image - Band 4 (NIR) after the correction
The map of analytical hillshading
Digital Elevation Model (DEM)
Sun azimuth = 137.1989028 degrees
Sun elevation angle = 61.8029487 degrees

7. The classification of the satellite images
1. The creation of the spectral signatures for each landcover type
- the differentiation of the spectral test areas (training sites)
- the creation of the spectral signatures
2. The classification of the
satellite images with the
maximum likelihood
method

8. The validation of the classification demonstrated that the accuracy is
between 87 and 93%. The most errors were detected in the extreme
shadow areas.
Because our study is focused only on the
timberline/treeline area, we eliminated all the areas
below 1400m and we grouped the landcover types in
four classes: pastures, shrubs, forests and waters.

9. THE CHANGE DETECTION METHOD
Change detection image = Earlier image – Later image
In all the change detection images we could observe that there are areas with
significant changes (the values of the pixels were beyond + 2SD or -2SD)

10. THE LAND CHANGE MODELER TOOL (Idrisi software)
- is based on cross-tabulation analysis that compares two
landcover images of the same area from different periods of time
The gains and losses of the landcover types
in Retezat – Godeanu Massif (1988-2004)

11. Net change of the landcover types
in Ţarcu and Godeanu Mountains

12. In the massifs where the pasturage was
very intense the natural boundaries of the
forest domain have changed.
The treeline ecoton has been destroyed by
burning of the subalpine shrubs and by
clearing

13. The intensity of the pasturage activity could be
expressed by the density of the sheepfolds in the
alpine area (numbers of sheepfolds/km2).

14. The Godeanu and the Cernei Mountains
1965
(Emm. de Martonne, 1921
2008
2006
SPOT, 2.5 m resolution

15. 2008
2008

16. Gains and losses in forests in Tulişa Mountains
Gains and losses in shrubs in Tulişa Mountains

17. Muntele Mic Massif

18. Areas with no evident changes
The Retezat Mountains -the
first national park in Romania
(1935).
There are no changes of the
timberline.
The treeline ecoton is present
and well preserved.
There is no advance of the
forest because the timberline
is mainly geomorphologicaly
determined.

19. The gains and losses of the
landcover types in Făgăraş
Mountains (1986-2000)
The Northern The Southern
Slope Slope

20. Avalanche paths that penetrate the forest on the northern slope
of the Făgăraş Mountains
The map of the geomorphological risk in
Balea Valley

22. The comparison between the timberline in 1953 and in 2008 on the
northern slope of the Făgăraş Mountains
1953
SPOT, 2008

23. The gains and losses of the landcover
types on the southern slope of the
Făgăraş Mountains (1988-2004)
SPOT, 2008

24. Comparison between the theoretical (climatic)
timberline and the real timberline
The Northern Slope
The Southern Slope

25. The Arjana Massif - the lowest area (1512 m) in Southern
Carpathians where subalpine level was identified
1952
1952
Airphoto, 2005

26. SPOT, 2008
1952
1.72 ha
Airphoto, 2005

27. CONCLUSIONS
• The human impact in the subalpine and alpine levels, especially the
grazing, has a great contribution in shaping the present day timberline
configuration.
• In almost all areas with intense pasturage activities the treeline ecoton
has been destroyed and the timberline is 300-400 m lower than the
theoretical (climatic) limit of the forest.
• In the areas with abandoned alpine pastures the dominant process is the
advance of the shrubs and spruce seedlings. In some cases we noticed
also the recover of the timberline. At low altitudes this process is more
intense i. e. Arjana Massif.
• In the protected areas (Retezat National Park) there are no significant
changes of the timberline. The treeline ecoton is also well preserved.
• In the areas where the timberline is a geomorpholgical one, there are
also no important changes (the northern slope of the Fagaraș Mountains
and the Retezat Mountains).
• Although there is an obvious trend of the temperature to increase we
could not established if the process of the forest recover is a consequence
of the climatic change

28. In the further studies:
- to improve the method for the reducing the topographic effect
- to use satellite images with very high resolution
- to establish representative test areas for the monitorization of the
vegetation changes
- to collect climatic data from the timberline area using data loggers
THANK YOU !