popa et all final
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8/9/2019 Popa Et All Final
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Drought Effects on Forest Health and Growth in the Western Partof the Eurasian Steppe Region
Ionel POPA, Ovidiu BADEA, Stefan NEAGU, Sefan LECA, Constantin NECHITAForest Research and Management Institute-Romania (ICAS)Bd. Eroilor 128, 077190 Voluntari, jud. Ilfov, Romania, popaicas@gmail.com, www.icas.ro
Introduction
Material and Methods
Results
Conclusions
Acknowledgments
Regional warming and consequent higher water deficits
along with air pollution are, most likely, the main drivingforces behind forest health and growth dynamics. They aremore important in the case of forest ecosystems existingunder marginal or restricted ecological conditions such insouth and south-eastern part of Romania (western part ofEurasian steppe).
The objective is to investigate the climate influence on
forest health and tree growth on south and south- easternpart of Romania.
Data sets: defoliation data from the period 1992-2013 (share
of damaged trees – defoliation classes 2-4) and climate datafrom E-OBS grid database. Tree ring chronologies forQuercus species analyzed by dendrochronological methods.
Forest health dynamics
0
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90
1990 1995 2000 2005 2010 2015
% o f d a m a g e t r e e s
Year
Allspecies ECS C SM A
0
10
20
30
40
50
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80
90
1990 1995 2000 2005 2010 2015
% o f d a m a g e t r e e
s
Year
Broadleaves ECS C SM A
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90
1990 1995 2000 2005 2010 2015
% d a m a g e t r e e s
Year
Quercusspp. ECS C SM A
Biogeographic region of Romania (adapted from EEA) – ICP Level I network
Dynamics of share of damaged trees by regions
Species located in the southern and south-eastern Romania under
extreme continental and steppe climate (e.g. oak species and blacklocust) are the most affected (22-43% share of damaged trees)comparing with beech (11%) and spruce (9%) situated on sub-mountain and alpine region.
IUFRO, Salt Lake City, USA, 6-11 of October, 2014
The share of damaged trees reached the highest values in
1994, after a prolonged period of drought since 1981. After1996 a slow increase of trees health is observed. This trend ismore evident after 2001 due to a important increase of
precipitation amount in the regions with hot and dry climate(ESC) and continental climate (C).
Climate influence on forest health
-0.15
-0.10
-0.05
0.00
0.05
pA_pA pS_pN pD_M A_A pS_A
C o r r . K e n d a l l
Season
Nationallevel
Allspecies Broadleaves Conifers Piceaa. Faguss. Quercusspp.
-0.2
-0.1
0.0
0.1
pA_pA pS_ pN pD _M A_ A pS_A
C o r r . K e n d a l l
Season
Allspecies ECS C SM A
-0.3
-0.2
-0.1
0.0
0.1
0.2
pA_pA pS_pN pD _M A_ A pS_ A
C o r r . K e n d a l l
Season
Broadleaves E CS C S M A
-0.3
-0.2
-0.1
0.0
0.1
pA_ pA pS_pN pD _M A_A pS_A
C o r r . K e n d a l l
Season
Quercusspp. ECS C
SM A
Kendall’s tau correlation between the share of damaged trees andprecipitation at national and regional level
0.00
0.05
0.10
0.15
0.20
0.25
1 99 2 1 99 3 1 99 4 1 9 95 1 99 6 1 99 7 1 99 8 1 99 9 2 00 0 2 00 1 2 00 3 2 00 4 2 00 5 2 00 6 2 0 07 2 00 9 2 01 0 2 01 1 2 01 2 2 01 3
P a r t i a l R 2
Year
All species p _A_A p _pD _M p _pS _pN p _pA_pA t _A_A t _pD _M t _pS _pN t _pA_pA
0.00
0.05
0.10
0.15
0.20
0.25
0.30
1 99 2 1 99 3 1 9 94 1 99 5 1 99 6 1 99 7 1 99 8 1 99 9 2 00 0 2 00 1 2 00 3 2 00 4 2 00 5 2 00 6 2 00 7 2 00 9 2 01 0 2 01 1 2 0 12 2 01 3
P a r t i a l R 2
Year
Broadleaves
Multiple linear regression analysis between share of damaged trees andseasonal temperature and precipitation
0.00
0.10
0.20
0.30
0.40
0.50
1 99 2 1 99 3 1 99 4 1 99 5 1 99 6 1 99 7 1 99 8 1 99 9 2 00 0 2 00 1 2 00 3 2 00 4 2 00 5 2 00 6 2 00 7 2 00 9 2 01 0 2 01 1 2 01 2 2 01 3
P a r t i a l R 2
Year
Quercus spp.
Climate influence on share of damage trees is relatively low(r =0.1-0.2 at national level and r = 0.2-0.3 at regional level max max
mainly of south and south-eastern Romania). Generally,precipitation is the main climatic driver on tree defoliation, anegative correlation has been observed for mainspecies/group of species. High variability of the correlationamong biogeographic regions was revealed.
Variance of defoliation explained by climate decreased in the
last years for all species and broadleaves. For oak speciesthe variance explained by climate remain over 20% during theanalyzed period.
Climate influence on tree growth
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
pS pO pN pD I F M A M I I A
C o r r e l a t i o n c o e f .
Month
Quercusrobur P LO A S TF A
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
pS pO pN pD I F M A M I I A
C o r r e l a t i o n c o e f .
Month
Quercus cerris G I RA V I DA V I DB
The growth of oak species from south of Romania is limited
by the precipitation amount from current growing season.The intensity of monthly correlations varies betweenspecies. The analysis of the spatial correlation between treering index and seasonal precipitation allowed to establish
the representativeness of each site.
Drought represent the main driving factor for forest health
and tree growth in the south and south-east of Romania(western part of Eurasian steppe).
Significant improvement of forest health from the south and
south-east of Romania was observed in the last years linkedto a improvement of water balance.
These forests are the only line of defense against the
Eurasian steppe expansion.
This research was supported by Romanian Authority forResearch in Core Program for forestry – GEDEFOR - projectPN09460110.
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Q u e r c u s f r a i n e t t o
Q u e r c u s p u b e s c e n s
R o b i n i a
p s e u d o a c a c i a
Q u e r c u s c e r r i s
Q u e r c u s r o b u r
Q u
e r c u s p e t r a e a
F a g u s s y l v a t i c a
P i c e a a b i e s
% o f d a m a g e d t r e e s
Dynamics of share of damaged trees at national level (4x4 km)
Correlation between tree ring index and precipitation from south Romania
These forests are the only line of defense against the Eurasian steppe expansionThese forests are the only line of defense against the Eurasian steppe expansion
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