Combining community resurvey data from
multiple regions to advance global change
research
Kris Verheyen, Pieter De Frenne, Lander Baeten, Don Waller, Radim
Hédl, Markus Bernhardt-Römermann and the forestREplot-network
Threatened biodiversity
Multiple drivers
MEA (2005)
Long-term community layer resurvey data, an
invaluable resource for global change research
Lameire, Honnay, Hermy 2000 J Veg Sci
Quasi
(Semi-)Permanent
Plots
X
Hermy 1978
1998
4
Long-term community layer resurvey data, an
invaluable resource for global change research
Long-term community layer resurvey data, an
invaluable resource for global change research
6
~1970
~2010
Long-term community layer resurvey data, an
invaluable resource for global change research
7
Moritz et al. (2008)
Take-home message
• Long-term community resurveys are an invaluable
resource and we need more of them
• To understand the – often interactive – effects of
multiple global change drivers, often acting at the
same time, resurvey data from multiple regions need
to be combined for joint-analyses
Multiple drivers acting at the same time
Smith et al. (2009)
Combining community resurvey data from multiple
regions to advance global change research
Canopy Openness
Verheyen et al. (in prep.)
Combining community resurvey data from multiple
regions to advance global change research
Increasing …*
– Orthogonality
– Representativeness
– Comprehensiveness
* Criteria for ecol. research platforms according to Nadrowski
et al. (2010)
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Multi-region resurveys complement globally
distributed experiments
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GLORIA: a prime example of a multi-region
resurvey initiative
www.gloria.ac.at
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Pauli et al. (2015)
Pauli et al. (2012)
GLORIA: a prime example of a multi-region
resurvey initiative
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forestREplot: an example of a long-term multiregion resurvey initiative
www.forestreplot.ugent.be
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forestREplot: focus on temperate forests
Adapted from Olson et al. (2001)
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forestREplot: focus on ground layer vegetation
- > 80 % vascular plant diversity
- important functional role
- early warning potential
forestREplot: clear criteria for dataset inclusion
Min. 20 (quasi-)permanent plots per region with a minimum intercensus interval of 20 years
www.forestreplot.ugent.be
18
forestREplot: current status
Europe: 49 datasets and ~2650
plot pairs
North America: 6 datasets and
~250 plot pairs
Mean survey interval: > 35-40 yrs
www.forestreplot.ugent.be
19
www.box.com
forestREplot, a collection of standardized excel-files
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forestREplot, selected results
2012
23 datasets, 1205 plot pairs
Objectives
Using resurvey data sets from multiple regions along a large deposition
gradient across the temperate zone of Europe, we wanted ....
1) To assess whether species richness and vegetation composition
have changed during the period between the surveys
2) To verify whether changes in richness and composition were
larger in regions with higher atmospheric deposition rates and to
check for interactions with other GC drivers
23 studies from 8 countries
Data analysis
Meta-analytical
approach with
individual
plot data
Designed
monitoring
schemes
Change in species richness
Average SRold = 17.69 versus SRnew = 17.35
Idiosyncratic
response
Change in Ellenberg values
Average Nold = 5.46 versus Nnew = 5.59
Average Lold = 4.66 versus Lnew = 4.62
It was shown that the observed eutrophication signal is mostly caused
by an increased input of better decomposable litter to the forest floor,
and not by increased atmospheric N deposition
forestREplot, selected results
2015
39 datasets, 1994 plot pairs
forestREplot, selected results
Importance of canopy changes confirmed, BUT it was also found that nitrogen
deposition does have an effect on richness/diversity in regions with low
(cumulated) deposition at the time of the first survey
forestREplot, selected results
2013
29 datasets, 1409 plot pairs
Microclimate can buffer macroclimatic changes
P<0.001
P<0.001
P<0.05
Lower thermophilization in forest plots that became denser over time
Take-home message
• Long-term community resurveys are an invaluable
resource and we need more of them
• To understand the – often interactive – effects of
multiple global change drivers, often acting at the
same time, resurvey data from multiple regions need
to be combined for joint-analyses