You cannot step twice into the same river: the transformation of Central European temperate forest communities over the past century Radim Hédl, Markéta Chudomelová, Martin Kopecký, Martin Macek, Vladan Riedl, Péter Szabó, Jan Šipoš, Ondřej Vild
You cannot step twice into the same river (in a place of an ecological theory, 2500 years old) Παντα θει Everything is flux (Heraclitus) Studying vegetation dynamics focus on temporal changes focus on variation between sites carefully make some generalizations fauxphilnews.wordpress.com/ 2012/10/17/heraclitus-2012/
Recent environmental changes - habitat fragmentation and loss - changed nutrient balance (surplus of N, acidification) - climate change - biotic invasions etc. Biodiversity decline - decreasing local diversity - biotic homogenization - decreasing functional diversity etc. But really?
No net change in species richness resurveys of vegetation plots (usually after several decades) Vellend et al., 2013, PNAS 5-261 years resurveys Bernhardt-Römermann et al., 2015, GCB 17-75 years resurveys
Generally nutrient-richer, shadier forests resurveys, indirect estimation Ellenberg N Verheyen et al., 2012, JEcology Ellenberg L
Biodiversity in temperate forests: focus on the herbaceous vegetation» soil» climate» topography» herbivory» competition» forest management change time 2015
The past forest management Historical forest database for Moravia (E-Czech Republic) MS Access, 4 historians entering all possible archival data on forest species composition, management etc. www.longwood.cz
Fagus and Picea distribution 11 th --19 th century archival data Moravia (E-Czech Rep.) 28,000 km 2 Source: historical forest database, www.longwood.cz
Past forest management Coppicing, 19 th century Moravia (E-Czech Rep.) 28,000 km 2 Source: historical forest database, www.longwood.cz
Past forest management Coppicing, 18 th century Moravia (E-Czech Rep.) 28,000 km 2 Source: historical forest database, www.longwood.cz
Coincidence of the 19 th c. coppicing and occurrence of species groups Group Asarum europaeum Significant factors: - altitude - mollisols - acidic cambisols NOT coppicing Group Geranium sanguineum Significant factors: + coppicing -altitude NOT soils Moravia, E-Czech Republic, 28,000 km 2
Re-survey of forest vegetation plots in the Czech Republic potentially ca. 50 thousand historical plots 1930s 1980 resampling started in the early 1990s mostly forestry typology survey (1950s present) Semi-permanent plots (approximate location by map, coordinates etc.) Database of resurveyed forest plots www.longwood.cz 1953 2004
Current analysis 15 localities 1806 samples / 903 plots old samples 1953-1978 resampling 2002-2014 altitude 165-950 m asl. plot size 400 500 m 2 altitude (m asl.) 1000 800 600 400 200 0 Distribution of plot altitudes 0 200 400 600 800 1000 included other
Change between the surveys 15 localities, 1806 samples 1953 2014 altitude 165-950 m asl. Boří les Hodonínská Dúbrava Bzenecká Dúbrava Kapánsko Polabí Milovický les Krumlovský les Ždánický les Děvín Chřiby Středohoří-Lovosice Středohoří-Litoměřice Bílé Karpaty Rychlebské hory Velká Javořina species richness lowland upland highland -30-20 -10 0 10 20 30 40 No. species per plot (mean, SD)
Change between the surveys 15 localities, 1806 samples 1953 2014 altitude 165-950 m asl. Boří les Hodonínská Dúbrava Bzenecká Dúbrava Kapánsko Polabí Milovický les Krumlovský les Ždánický les Děvín Chřiby Středohoří-Lovosice Středohoří-Litoměřice Bílé Karpaty Rychlebské hory Velká Javořina EIV nutrients lowland upland highland -3-2 -1 0 1 2 3 Plot-wise change (mean, SD)
Change between the surveys 15 localities, 1806 samples 1953 2014 altitude 165-950 m asl. Boří les Hodonínská Dúbrava Bzenecká Dúbrava Kapánsko Polabí Milovický les Krumlovský les Ždánický les Děvín Chřiby Středohoří-Lovosice Středohoří-Litoměřice Bílé Karpaty Rychlebské hory Velká Javořina EIV light lowland upland highland -3-2 -1 0 1 2 3 Plot-wise change (mean, SD)
Change between the surveys 15 localities, 1806 samples 1953 2014 altitude 165-950 m asl. Boří les Hodonínská Dúbrava Bzenecká Dúbrava Kapánsko Polabí Milovický les Krumlovský les Ždánický les Děvín Chřiby Středohoří-Lovosice Středohoří-Litoměřice Bílé Karpaty Rychlebské hory Velká Javořina EIV moisture lowland upland highland -3-2 -1 0 1 2 3 Plot-wise change (mean, SD)
Change between the surveys 15 localities, 1806 1953 2014 altitude 165-950 m asl. old survey Beta-diversity new survey mean dissimilarity
Sensitive species Uncommon but sensitively indicating long-term environmental changes 16 spp. 15 spp. 5 spp. y-axis: % of all occurrences in old or new surveys note the scaling differences images source: commons.wikimedia.com
Invasive species: focus on Impatiens Other possibly important factors: - soil texture / moisture - disturbances
Conclusions Species diversity consistent with the existing studies, no net change in species richness. Invasive species increased, orchids and wintergreens decreased. Environmental changes consistent with previous studies (nutrients, light, moisture). No pattern along altitude/forest management was observed.
Ongoing research: getting more detailed explanatory data plot/site wise data on management history better data on abiotic environment (soil, light, deposition etc.) inclusion of species traits
Historical management as explanatory factor For each (re)survey period management form tree species composition forest stand age intensity of the most recent cutting stand density / tree volume non-forestry uses game density and composition Two periods: - medieval to 1850-1850 to present
Creating a historical-ecological database of resurveyed forest plots Management, level 1: prehistoric to 1850 Management, level 2: 1950 present Environmental influences: deposition, temperature
Thank you The research leading to these results has received funding from the European Research Council under the European Union s Seventh Framework Programme (FP7/2007-2013) / ERC Grant agreement no 278065. www.longwood.cz