Project

Back to overview

Invasibility of Swiss Grasslands

Applicant Stampfli Andreas
Number 127246
Funding scheme Project funding (Div. I-III)
Research institution Hochschule für Agrar-, Forst- und Lebensmittelwissenschaften HAFL Berner Fachhochschule BFH
Institution of higher education Berne University of Applied Sciences - BFH
Main discipline Ecology
Start/End 01.01.2010 - 30.09.2013
Approved amount 288'000.00
Show all

Keywords (15)

biodiversity; climate change; extreme drought; meadow; propagule pressure; resilience; resistance; seed bank; seed rain; seedling establishment; soil moisture; exotic species; drought; productivity; seed addition experiment

Lay Summary (English)

Lead
Lay summary
Ecological processes resulting from global change, such as more frequent extreme summer drought or increased propagule pressure of exotic species, often affect plant communities gradually at time scales of years or decades and may therefore not often be distinctly recognized. The effects of potential interactions of such processes are largely unknown. Interactions may partly compensate single effects and contribute to constancy of communities and ecosystems. However, ecologists are increasingly concerned about potentially adverse interactions that may stimulate cascades of species extinctions.Over the last decade sowing experiments have found reliable evidence for seed-availability related effects on the local occurrence of species, the size of populations and the richness and productivity of communities. This implies that processes influencing the production and dispersal of seeds and/or the establishment of seedlings are important for the functioning of ecosystems.Although major cases of adverse invasions have not occurred so far, we suspect that species-rich meadows that show a high seedling turnover are potentially susceptible to invasion. Current invasibility theory predicts increased invasion during temporary resource pulses that could be associated with increased variability of rainfall. Successful invasion may primarily depend on the propagule pressures of local resident and potential invader species. A new multi-factorial seed-addition experiment will investigate hypotheses concerning the main and interactive effects of productivity, summer drought, origin of species, and propagule pressure. The experiment will be started in 2010 in meadows covering a wide productivity gradient in different Swiss regions. The knowledge gained from this experiment will be used to predict grassland invasibility in Switzerland.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Biotic resistance to plant invasion in grassland: Does seed predation increase with resident plant diversity
Preukschas Juliane, Zeiter Michaela, Fischer Markus, Stampfli Andreas (2014), Biotic resistance to plant invasion in grassland: Does seed predation increase with resident plant diversity, in Basic and Applied Ecology, 15, 133-141.
Seed availability in hay meadows: Land-use intensification promotes seed rain but not the persistent seed bank
Zeiter Michaela, Preukschas Juliane, Stampfli Andreas (2013), Seed availability in hay meadows: Land-use intensification promotes seed rain but not the persistent seed bank, in Agriculture, Ecosystems and Environment, 171, 55-62.
Positive diversity-invasibility relationship in species-rich semi-natural grassland at the neighbourhood scale
Zeiter M, Stampfli A (2012), Positive diversity-invasibility relationship in species-rich semi-natural grassland at the neighbourhood scale, in Annals of Botany, 110(7), 1385-1393.

Collaboration

Group / person Country
Types of collaboration
Universität Bayreuth, Abteilung Disturbance Ecology Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
ART Zürich, Forschungsgruppe Lufthygiene/Klima Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
56th IAVS Symposium Vegetation patterns and their underlying processes Talk given at a conference Invasibility of Swiss grasslands: interactive effects of summer drought, site productivity and propagule pressure 26.06.2013 Tartu, Estonia Stampfli Andreas; Zeiter Michaela;
56th IAVS Symposium Vegetation patterns and their underlying processes Talk given at a conference Resilience of semi-natural grassland: summer drought alters fine-scale diversity-invasibility relationship 26.06.2013 Tartu, Estonia Zeiter Michaela; Stampfli Andreas;
Seminar, Plant Nutrition Group, ETH Zürich, Lindau-Eschikon Individual talk Influence of drought on semi-natural grassland 28.02.2013 Lindau-Eschikon, Switzerland Stampfli Andreas;
Vortragsreihe Ökologie und Umweltforschung, Bayreuth Center of Ecology and Environmental Research, Bayreuth Individual talk Invasibility of Swiss Grasslands 31.01.2013 Bayreuth, Germany Stampfli Andreas;
Plant population biology conference 2012 (GfÖ) Talk given at a conference Invasibility of Swiss Grasslands: Interactive effects of summer drought, site productivity and propagule pressure 17.05.2012 Zürich, Switzerland Stampfli Andreas; Zeiter Michaela;
Plant population biology conference 2012 (GfÖ) Poster Seed predation in Swiss semi-natural grasslands 17.05.2012 Zürich, Switzerland Preukschas Juliane; Stampfli Andreas; Zeiter Michaela;
Plant population biology conference 2012 (GfÖ) Poster Is semi-natural grassland resilient to extreme drought? 17.05.2012 Zürich, Switzerland Stampfli Andreas; Zeiter Michaela;
10th International NCCR Climate Summer School "Climate Change, Extremes and Ecosystem Services" Poster Soil seed bank and seed rain in Swiss semi-natural meadows 04.09.2011 Grindelwald, Switzerland, Switzerland Stampfli Andreas; Preukschas Juliane; Zeiter Michaela;
SNSF Division III, Interactive conference: life sciences and health research at universities of applied sciences Talk given at a conference Invasibility of Swiss Grasslands 08.07.2011 Bern, Switzerland Stampfli Andreas;
Plant population biology conference 2011 (GfÖ) Poster Positive diversity-invasibility relationship in species-rich meadow at neighbourhood scales 02.06.2011 Oxford, Great Britain and Northern Ireland Zeiter Michaela; Stampfli Andreas;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions (Postersession) Globaler Wandel: Kann die Degradation der Schweizer Wiesen aufgehalten werden? German-speaking Switzerland 2011

Associated projects

Number Title Start Funding scheme
149862 Drought legacy effects on grassland invasibility 01.04.2014 Project funding (Div. I-III)
100612 Influence of droughts on regeneration and vegetation change 01.04.2003 Project funding (Div. I-III)
112639 Influence of droughts on regeneration, vegetation change and ecosystem functioning 01.04.2006 Project funding (Div. I-III)
149862 Drought legacy effects on grassland invasibility 01.04.2014 Project funding (Div. I-III)

Abstract

Ecological processes resulting from global change, such as more frequent extreme summer drought or increased propagule pressure of exotic species, often affect plant communities gradually at time scales of years or decades and may therefore not often be distinctly recognised. The effects of potential interactions of such processes are largely unknown. Interactions may partly compensate single effects and contribute to constancy of communities and ecosystems. However, ecologists are increasingly concerned about potentially adverse interactions that may stimulate cascades of species extinctions.Over the last decade sowing experiments have found reliable evidence for seed-availability related effects on the local occurrence of species, the size of populations and the richness and productivity of communities. This implies that processes influencing the production and dispersal of seeds and/or the establishment of seedlings are important for the functioning of ecosystems. However, most of these experiments have applied seed additions at one single level of density. With such an approach, the degree of seed limitation cannot be quantified and the relationship between seed rain (propagule pressure) and number of successfully establishing species has remained obscure. Yet, the natural seed rain as also the production of seeds (community fecundity) have not been measured in the context of seed-addition studies and we still lack the information on how many species and/or individuals may be added to a saturation of the community and how many propagules are needed to reach species saturation of the community.Although major cases of adverse invasions have not occurred at our study sites so far, we suspect that species-rich meadows that show a high seedling turnover are potentially susceptible to invasion. Current invasibility theory predicts increased invasion during temporary resource pulses that could be associated with increased variability of rainfall. Successful invasion may primarily depend on the propagule pressures of local resident and potential invader species. Building up on our experience of vegetation dynamics based on experimentation and long-term monitoring in semi-natural grassland communities we propose a new multi-factorial experiment to investigate hypotheses concerning the main and interactive effects of productivity, summer drought, origin of species, and propagule pressure. A seed-addition experiment will be performed at 20 localities covering hay meadows over a wide productivity gradient in each of five regions of Switzerland. Seed-additions treatments that result from the combination of the factor propagule pressure (levels of augmented seed density) and the factor seed origin (two inocula representing indigenous grassland species or exotic species) will be arranged within plots that will receive normal or strongly reduced summer rain. Propagule pressure will be augmented to create communities close to species saturation. This will provide a measure of community invasibility. The ambient seed availability will be determined using representative topsoil samples at each site for reference. Seed-addition experiments will be started in 2010 and run over a period of 2 years. We intend to include many sites within recently listed meadows of Swiss “national importance”.This field experiments in natural grassland bridges the gap between current progress in theory and shortcomings of recent seed-additions experiments. Our aim is to further elucidate the relationship between community invasibility and productivity and to fundamentally advance our understanding of vegetation dynamics. Based on the results of this experiment we wish to develop a robust framework for the prediction of grassland invasibility in Switzerland and to make an important step forward in the prediction of global-change effects on herbaceous vegetation.
-