Müller-Schärer Heinz
Does fire promote germination and establishment of the endangered plant species Blitum virgatum?
Project Number: CH-4852
| Project Type: |
Master |
| Project Duration: |
06/01/2007 - 06/30/2008 project completed |
| Funding Source: |
other , |
| Leading Institution: |
Université de Fribourg |
| Project Leader: |
Prof. Heinz Müller-Schärer
Ecology & Evolution
Dépt. de Biologie
Université de Fribourg
Chemin du Musée 10
1700 Fribourg
Phone: +41 (0) 26 300 88 35 ; +41 (0) 26 300 88 10
FAX: +41 (0) 26 300 97 40
e-Mail: heinz.mueller(at)unifr.ch
http://www.unifr.ch/biol/ecology/ |
Research Areas:
Disciplines:
Keywords:
Blitum virgatum, Chenopodium album, fire, seed bank, population dynamics
Abstract:
A human-caused, intensive fire destroyed a 300 ha coniferous forest in the Valais above Leuk and burned the vegetation completely down. Blitum virgatum was observed in great abundance two years after the fire event. B. virgatum is an endangered plant species and is known to occur on ruderal places, but almost nothing is known about its ecology and population dynamics.
B. virgatum did not occur in the proximity of the burnt area before the fire. During the first year after disturbance in plant communities, vegetation reestablishment take place by pioneer species and other plant species, which are adapted to disturbance event e.g. by the building up of persistent seed banks. We wanted to know, if this approach of building up a seed bank is followed by B. virgatum. We did a seed bank study in the intact forest near by the burnt area to investigate the potential origin of the seed and to determine the content of viable B. virgatum seeds and other plant species in the soil.
A second aspect was to look at the relationship of the appearance of B. virgatum plants and the fire event. In fire-prone species heat and smoke or ash are known to increase germination and early growth. We wanted to examine the effect of the fire components heat, smoke and ash on the germination and early growth of B. virgatum. Ch. album, a plant with similar ecological needs, served as reference to contrast a species-specific response to fire.
In our study, B. virgatum seeds were present in the forest soil. B. virgatum seeds are supposed to be remnants from earlier cultivation and dispersed into the forest by grazing livestock. It remains unknown, how long seeds are able to stay viable in the soil and ask for further investigations about the persistence of B. virgatum seeds. We did not find many plant species in the forest soil and seed bank density was lower than in other studies. Seed number did in contrary to other findings increase with altitude and can be explained by the two most occurring plant species on given altitude.
The fire components heat, smoke and ash did in general increase the performance of B. virgatum, but had no or a negative effect on the performance of Ch. album and highlights the positive effect of fire on B. virgatum. The abundance of B. virgatum increased consistently on the burnt surface in the 2nd and 3rd year after the fire event. The establishment, growth and seed production B. virgatum were probably promoted by increased light and nutrient availability and the dispersal of seeds was promoted by animals and people over the burnt area. B. virgatum occurs not just after fire, but also on non-fire related sites in Switzerland. Therefore the abundance of B. virgatum is not fire dependent but positively influenced by fire and a candidate for so called fire-prone species.
Leading questions:
What is the potential origin of B. virgatum seeds on the burnt surface above Leuk?How is the relationship between fire components (heat, smoke and ash) and the appearance of B. virgatum plants?
Publications:
Buholzer, Lydia. 2008. Does fire promote germination and establishment of the endangered plant species Blitum virgatum? Department of Biology, Ecology & Evolution, University of Fribourg.
Last update: 12/29/16
Source of data: ProClim- Research InfoSystem (1993-2024)
Update the data of project: CH-4852
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