combining long-term plot resurvey and historical management data

Towards an integrated research platform
of the Czech forest vegetation:
combining long-term plot resurvey
and historical management data
Radim Hédl, Péter Szabó, Martin Kopecký,
Markéta Chudomelová, Ondřej Vild,
Martin Macek, Petr Petřík, Silvie Suchánková,
Tadeáš Štěrba, Václav Zouhar
Long-term vegetation change:
the black-box we would like to open
Drivers of change
t0
time
? linearity
? forecasting
t1
The four oft-quoted drivers of
forest vegetation change
in the Anthropocene
1. Management + land-use
2. Atmospheric deposition
3. Ungulates (big herbivores)
4. Climate change
http://www.metmuseum.org/toah/works-of-art/19.73.209
Resurvey of forest vegetation plots
in the Czech Republic
• potentially 60 thousand plots from the 1930s–1980s
• first resampling studies in the 1990s
• semi-permanent plots
approximate location by old map, topography, coordinates, etc.
2015
Re-survey of forest vegetation plots
in the Czech Republic
Plots established during the forestry typology survey
•
•
•
•
•
•
Forest Management Institute (UHUL)
1951-1980 the main sampling wave
91 authors
39,000 plots; 3 per 100 ha
59% in non-natural forests (regularly managed)
digitalized (Turboveg, Access)
2015
Resampled forest plots, Czech Rep.
1991-2015, mainly 2012-2015
About 1500 plots (3000 samples); 3-5(-8) a day
2016-2018
number of plots
Resampled forest plots, Czech Rep.
sampling year
original samples
repeated samples
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An example: Rychlebské hory
Rychlebské hory
280 km2
About 400 plots from 1958-1960, partly 1964-1965
Single authorship
165 plots revisited in 2014-2015
129 plots resampled (R. Hédl, M. Chudomelová)
elevation (m a.s.l.)
Plot size usually 500 m2, circular
Elevation 370-985 m
1050
Alluvial to spruce forests
950
850
750
650
550
450
350
0
10
20
30
40
50
60
70
80
plot rank
Resampling: only when vegetation not completely altered
2014: 72 plots resampled, 22 cancelled)
2015: 57 plots resampled, 14 cancelled)
129 plots resampled: 72%
36 plots cancelled: 28%
90
100
110
120
Species diversity: obvious authorship bias
number of species per plot
plot size 500 m2
druhů
nr.Počet
of species
80
70
80
75
70
65
60
60
50
50
40
40
30
30
20
20
10
10
0
0
60
57
57
staré
old
nové
new
nové
staré
0
10
20
30
40
50
60
70
80
90
100
plot rank
Who cares about averages?
They may be under/overestimates.
110
120
Vegetation coverage:
another area of strong authorship bias
2 sites, resurveyed forest plots, CZ
60
40
20
coverage
(%)
zapoj odhadnuty
coverage (%)
80
Tree layer coverage
1965
2012
Did the forest canopy become sparser?
The opposite is true (analysis of aerial photos, EIV-L)
Multiple-site resurvey
• 15 sites, 1806 samples
• 1953–2014
• 165-950 m asl.
species richness
Boří les
lowland
Hodonínská Dúbrava
Bzenecká Dúbrava
Kapánsko
Polabí
Milovice Wood
Děvín Wood
=
abandoned coppices
Milovický les
Krumlovský les
Ždánický les
upland
Děvín
Chřiby
Středohoří-Lovosice
Středohoří-Litoměřice
Bílé Karpaty
Rychlebské hory
highland
Velká Javořina
-30
-20
-10
0
10
20
30
40
No. species per plot (mean, SD)
Multiple-site resurvey
• 15 sites, 1806 samples
• 1953–2014
• 165-950 m asl.
EIV nutrients
Boří les
lowland
Hodonínská Dúbrava
Bzenecká Dúbrava
Kapánsko
Polabí
Milovice Wood
Děvín Wood
=
abandoned coppices
Milovický les
Krumlovský les
Ždánický les
upland
Děvín
Chřiby
Středohoří-Lovosice
Středohoří-Litoměřice
Bílé Karpaty
Rychlebské hory
highland
Velká Javořina
-3
-2
-1
0
1
2
3
Plot-wise change (mean, SD)
Which driver? We do not really know.
The case of the Milovice Wood (S Moravia).
1. long-term semi-permanent vegetation plot resurveys
2. estimation of environmental change by Ellenberg I.V.
Chytrý & Danihelka, 1993
Folia Geobotanica
… it’s deer!
Hédl et al., 2010
Diversity and Distributions
… no, it’s coppicing abandonment!
1953; 1992; 2006
Forest management
• The strongest driver of vegetation changes
• Includes land-use change, direct management,
ungulates (large herbivores)
Much of the interpretation of long-term change
is related to management.
…but there is little primary data-based evidence
Historical forest use database for Moravia
4 historians, 2 GIS-experts
MS Access
40,000 entries
ERC-LONGWOOD
www.longwood.cz
11th-20th century
hunting 17th
hunting 1940s
Coppicing, 19th century
Coppicing, 18th>19th century change
Forest pasture
Litter raking
Hay cutting
Management effects
Legacy
Events
t0
time
t1
Management influences vegetation at any time (past / present…).
Management leaves a legacy of its influence.
Plot-related management history
8 parameters
Both „legacy“ and „event“ (related to sampling date)
Archival survey (written documents, maps)
Two periods:
1: before 1850 (lower data quality)
2: after 1850 (good data quality)
Parameter
Type
Period
Management form
categorial
1, 2
Tree species composition
species, %
1, 2
Stand age
years
2
Last cutting type and intensity
categorial
2
Tree density / timber volume
nr./ha, m3/ha
1, 2
Non-timber uses
categorial
1, 2
Game density
nr./ha
2
Game composition
categorial, %
1, 2
The effects of historical management
• Requires thorough archival research
(primary data)
• Legacy
> long-lasting effects
> potential for vegetation databases
• Events
> actual influence at any time
> potential for resurveys