Vegetation ecology. Communities and dynamics. Pascal Vittoz MER

Transcription

1 Vegetation ecology Communities and dynamics Pascal Vittoz MER Winter excursion,

2 Plant communities Community: a part of the vegetation consisting of interacting populations, growing in a uniform environment, within a distinguishable time unit 2 van der Maarel 2005 Vegetation Ecology

3 Plant communities are the result of a succession of filters 3 Lortie et al Oikos

4 When filters change, vegetation changes Vegetation dynamics Vegetation ecology 4 Lortie et al Oikos

5 Vegetation dynamics or 1948? W. Lüdi or J.-L. Richard P. Vittoz 5

6 Drivers of the changes Climate change Nitrogen deposition 6 Jordi 2004 OFEFP

7 Land use changes Biotic exchange P. Vittoz 7 A. Elsig

8 Permanent plots Areas marked in the field to monitor plant composition Historical permanent plots st inventory (~1900) Recent inventory (~2000) Increase of species richness on alpine summits in 20 th century Nbre of species Altitude [m] Vittoz et al. 2009

9 Permanent.Plot.ch a data bank for Swiss permanent vegetation plots Available permanent plots in Permanent.Plot.ch project 9

10 120 new plots along elevational transects 5 transects (Jura, Outer Alps, Inner Alps) Forests and dry grasslands 10 Distribution of the plots along the transect of Salgesch (Valais) Forests Dry grasslands

11 Semi-permanent plots: relocalisation as precisely as possible of old plant inventories 11 Map and field book of J.-L. Richard ( ) PhD Magalì Matteodo

12 Shift in plant composition of subalpine grasslands in Vallon de Nant from 1970 to 2006 Calcareous grasslands in Vallon de Nant ( m) 12 Vittoz et al Global Change Biol.

13 Biological traits 13 Characteristics of a plant associated to its growth, morphology, reproduction, life span, dispersal ability or resistance Plant height Clonal growth Seed weight Ecological preferences Related to the plant ability to go through the environemental and biotic filters Interpretation of the observed changes in species composition Understanding of the common characteristics of the most reactive species to the changes

14 Species with efficient diaspores for wind dispersal are more prone to colonize new alpine summits under climate change 100 Diaspore appendage Proportion of species [%] None Fleshy Awn Wings Pappus 0 Colonizers p=0.041 Stables 14 Vittoz et al Bas. Appl. Ecol.

15 Species ecology and conservation Keller & Vittoz In press Alp Bot R. Keller P. Vittoz 15

16 Ecological conditions for a species can be assessed by In situ measurements Long-term climatic data Soil descriptions and laboratory measurements Models based on available data Experiments in different conditions Description of plant communities for which most of the species are already known Combinations of methods 16

17 Species distribution models based on GIS data document ecology at the regional scale Importance of topo-climatic variables in the species distribution models of Leontopodium alpinum Potential distribution of L. alpinum in Switzerland according to models 17 Ischer et al Folia Geobot

18 PCA based on 249 inventories of plant communities containing Leontopodium alpinum (7.4% de variance) 3. Drabion hoppeanae 6. Artemisio-Festucetum Seslerion 7. Astragalo-Seslerietum Seslerion 2. Elynion 1. Seslerio-Caricetum Seslerion 8. Caricion firmae 18 (10.1% de variance) Ischer et al Folia Geobot

19 Perspectives M. Matteodo 19 L. Liberati G. Perret

20 From plants to soil Relationships between plant communities and soil composition Dynamics of organic matter in soil Incorporation of organic matter in soil Humus changes under changing conditions Humus as indicator of the changes 20

21 PhD Magalì Matteodo Aor OH E E-BPh BPh BPs C1 C2 Evolution of subalpine-alpine vegetation under the influence of climate change and relationships with soil humus Aims How did subalpine-alpine vegetation change in the last 40 years? Incorporation of organic matter in soils What are the main causes of changes? C3 M. Matteodo 21

22 Swamp forests in Grande Cariçaie C. Clerc Biodiversity of the swamp forests in Grande Cariçaie: past and future dynamics of vegetation and soils Buts Forest dynamics of primary swamp forests Soil dynamics Relationships between vegetation and soil development 22 Excursion BGS

23 Thank you! F. Dessimoz, A. Dubuis, B. Fournier, A. Guisan, M. Ischer, S. Jutzeler, R. Keller, M. Matteodo, S. Maire, L. Pellissier, C. Randin, E. Verrecchia 23