Ice damages of coniferous trees in hemiboreal forests in

Ice damages of coniferous trees in
hemiboreal forests
in context of climatic changes:
case study in Latvia
Aris Jansons, Endijs Baders, Juris
Rieksts-Riekstins, Una Neimane
[email protected]
Ice damages in forest
(http://apollo.lsc.vsc.edu)
Average number of
days with ice
Ice damages in forest
6
5
4
3
2
1
0
Liepaja
Aluksne
10 11 12 1 2 3
Month of the year
4
LVĢMC
(Krauklis, 2006; http://chalk.richmond.edu)
There is no reason to believe,
that frequency of ice events will
decrease in future due to
climatic changes
Ice damages in forest
Ice damages:
• rare and difficult (impossible) to predict
• ice-load effect often mixed with wind-load
and can be mixed with snow load, therefore
generalization of results hardly possible
• measurement period stretched in time –
additional weight piled on trees in a form of
snow
Material & Methods
Ice storm in the end of December 2012
Sample plots placed in the most affected forest massive in
163 stands (98 pine, 51 spruce and 14 mixed)
Material & Methods
Stands were selected randomly within groups
determined by
age classes (from 20 to 120 years),
forest types (most common on dry, drained and wet
soils)
time after last thinning (up to 3 years and more than
3 years).
Ten circular sample plots (200m2) were systematically
placed within each stand
For each tree height, diameter, height of green crown
were measured
Damage assessment:
for broken trees – height of standing trunk,
for bent trees – height and angle of the curve or
angle of slope.
Material & Methods
Results
Ice damages, independently from dominant tree species, were
found for 27% of trees.
Results
Dominant tree species were not affecting the type
of damage: mostly broken tops – 18% of trees.
Results
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Spruce
Mixed
Sl
Nd
Mrs
Mr-ln
Mr
Ln
Ks
Dms
Dm
As
Ks
Dm
As
Vrs
Vr
Kp
Dms
Dm
As
Not damaged
Old damage
Bent
Broken
Pine
Forest type had a significant effect on proportion of damaged
trees (22-41%) as well as type of damage
Bent trees were detected in all forest types and the proportion
ranged from 4 to 29%
Results
Amount and type of damages was significantly affected by tree
dimensions
Results
Broken
Broken in green
crown
Broken below green
crown
Uprooted
Stand age had notable influence on proportion of damaged trees and type of
damages.
Thinning has a statistically significant effect on proportion of damaged
trees – it was higher after the thinning in stands of both species
Thank You!
Research was carried out in Forest Competence
Centre (ERAF) project „Methods and technologies for
increasing forest capital value” (No. L-KC-11-0004)
Aris Jansons, Endijs Baders, Juris Rieksts-Riekstins, Una Neimane &
Andis Adamovics, Juris Katrevics, Raitis Rieksts-Riekstins
[email protected]