Projekt

Zurück zur Übersicht

Invasibility of Swiss Grasslands

Gesuchsteller/in Stampfli Andreas
Nummer 127246
Förderungsinstrument Projektförderung (Abt. I-III)
Forschungseinrichtung Hochschule für Agrar-, Forst- und Lebensmittelwissenschaften HAFL Berner Fachhochschule BFH
Hochschule Berner Fachhochschule - BFH
Hauptdisziplin Oekologie
Beginn/Ende 01.01.2010 - 30.09.2013
Bewilligter Betrag 288'000.00
Alle Daten anzeigen

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 (Englisch)

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.
Direktlink auf Lay Summary Letzte Aktualisierung: 21.02.2013

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Publikationen

Publikation
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.

Zusammenarbeit

Gruppe / Person Land
Formen der Zusammenarbeit
Universität Bayreuth, Abteilung Disturbance Ecology Deutschland (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Forschungsinfrastrukturen
- Austausch von Mitarbeitern
ART Zürich, Forschungsgruppe Lufthygiene/Klima Schweiz (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Forschungsinfrastrukturen

Wissenschaftliche Veranstaltungen

Aktiver Beitrag

Titel Art des Beitrags Titel des Artikels oder Beitrages Datum Ort Beteiligte Personen
56th IAVS Symposium Vegetation patterns and their underlying processes Vortrag im Rahmen einer Tagung Invasibility of Swiss grasslands: interactive effects of summer drought, site productivity and propagule pressure 26.06.2013 Tartu, Estland Stampfli Andreas; Zeiter Michaela;
56th IAVS Symposium Vegetation patterns and their underlying processes Vortrag im Rahmen einer Tagung Resilience of semi-natural grassland: summer drought alters fine-scale diversity-invasibility relationship 26.06.2013 Tartu, Estland Zeiter Michaela; Stampfli Andreas;
Seminar, Plant Nutrition Group, ETH Zürich, Lindau-Eschikon Einzelvortrag Influence of drought on semi-natural grassland 28.02.2013 Lindau-Eschikon, Schweiz Stampfli Andreas;
Vortragsreihe Ökologie und Umweltforschung, Bayreuth Center of Ecology and Environmental Research, Bayreuth Einzelvortrag Invasibility of Swiss Grasslands 31.01.2013 Bayreuth, Deutschland Stampfli Andreas;
Plant population biology conference 2012 (GfÖ) Vortrag im Rahmen einer Tagung Invasibility of Swiss Grasslands: Interactive effects of summer drought, site productivity and propagule pressure 17.05.2012 Zürich, Schweiz Stampfli Andreas; Zeiter Michaela;
Plant population biology conference 2012 (GfÖ) Poster Seed predation in Swiss semi-natural grasslands 17.05.2012 Zürich, Schweiz 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, Schweiz 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, Schweiz Stampfli Andreas; Preukschas Juliane; Zeiter Michaela;
SNSF Division III, Interactive conference: life sciences and health research at universities of applied sciences Vortrag im Rahmen einer Tagung Invasibility of Swiss Grasslands 08.07.2011 Bern, Schweiz Stampfli Andreas;
Plant population biology conference 2011 (GfÖ) Poster Positive diversity-invasibility relationship in species-rich meadow at neighbourhood scales 02.06.2011 Oxford, Grossbritannien und Nordirland Zeiter Michaela; Stampfli Andreas;


Kommunikation mit der Öffentlichkeit

Kommunikation Titel Medien Ort Jahr
Referate/Veranstaltungen/Ausstellungen (Postersession) Globaler Wandel: Kann die Degradation der Schweizer Wiesen aufgehalten werden? Deutschschweiz 2011

Verbundene Projekte

Nummer Titel Start Förderungsinstrument
149862 Drought legacy effects on grassland invasibility 01.04.2014 Projektförderung (Abt. I-III)
100612 Influence of droughts on regeneration and vegetation change 01.04.2003 Projektförderung (Abt. I-III)
112639 Influence of droughts on regeneration, vegetation change and ecosystem functioning 01.04.2006 Projektförderung (Abt. I-III)
149862 Drought legacy effects on grassland invasibility 01.04.2014 Projektförderung (Abt. 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.
-