Report - ICP Forests

32 2. Large Scale Crown Condition Surveys
2.2.2.3 Pinus sylvestris
With up to 31 726 trees for the period
1998 – 2009 and up to 21 282 trees for
the period 1991 – 2009 Pinus sylvestris
is the tree species with the largest
number of trees in the sample. It covers
most regions in Europe and occurs on
Level I plots from Northern Scandinavia
to the Mediterranean region. Due to the
large sample number and its occurrence
throughout Europe regional differences
in crown condition are levelled off in the
aggregated results (Figure 2.2.2.3-1).
Crown condition is characterized by a
rather constant decrease in the share of
healthy trees from around 50% in the
mid 1990s to 35.4% in 2009.
This decrease is as well reflected in the
map of plots continuously monitored
since 1998 (Figure 2.2.2.3-2). The share
of plots with increasing defoliation
(13.9%) is clearly below the share of
plots with a decrease (26.8%). Plots
showing a deterioration are scattered
across Europe, but are specifically
clustered in southern France, at the
eastern edge of the Pyrenean mountains
and in Czech Republic. Decreasing
defoliation is specifically registered on
the plots in Belarus.
N trees 0-10% >10-25% >25%
1991 17768 27.1 37.4 35.5
1992 17194 28.4 36.3 35.4
1993 17225 27.6 38.5 33.9
1994 16570 26.8 37.0 36.2
1995 18754 33.4 37.3 29.3
1996 18790 35.2 40.8 24.0
1997 18824 34.8 42.9 22.3
1998 19205 35.9 45.0 19.1
1999 19468 36.1 46.2 17.7
2000 19447 34.5 47.5 18.0
2001 19562 33.4 49.2 17.5
2002 19486 31.2 50.2 18.6
2003 19477 29.9 51.4 18.7
2004 21092 33.2 48.1 18.7
2005 21282 34.5 46.3 19.2
2006 18651 38.1 45.5 16.4
2007 19251 35.6 48.8 15.6
2008 17695 33.9 49.4 16.7
2009 16042 35.4 47.1 17.5
N trees 0-10% >10-25% >25%
1998 30180 29.2 45.8 25.0
1999 30142 30.6 47.6 21.8
2000 29842 30.2 49.9 19.9
2001 29959 30.4 51.3 18.3
2002 29788 32.0 51.6 16.4
2003 30065 31.6 52.0 16.4
2004 31582 35.2 48.3 16.5
2005 31726 35.5 47.5 16.9
2006 28987 37.4 48.1 14.6
2007 29567 34.8 50.9 14.2
2008 28045 32.5 52.7 14.8
2009 26725 33.6 51.4 15.0
Percent of trees
100
80
60
40
0-10% (91-09)
>25% (91-09)
0-10% (98-09)
>25% (98-09)
20
0
1991
1993
1995
1997
1999
Year
Figure 2.2.2.3-1: Shares of trees of defoliation 0-10% and
>25% in two periods (1991-2009 and 1998-2009).
2001
2003
2005
2007
2009