Knüsting, J.; Brinkmann, M.C.; Silva, B.; Schorsch, M.; Bendix, J.; Beck, E. & Scheibe, R. (2018): <b>Who will win where and why? An ecophysiological dissection of the competition between a tropical pasture grass and the invasive weed Bracken over an elevation range of 1000m in the tropical Andes</b>. <i>PlosOne</i> <b>13</b>, 1-24.
Resource Description
Title:
Who will win where and why? An ecophysiological dissection of the competition between a tropical pasture grass and the invasive weed Bracken over an elevation range of 1000m in the tropical Andes
email:
bendix <at> staff.uni-marburg.de
Faculty of Geography
Deutschhausstraße 10
Philipps University of Marburg
Laboratory for Climatology and Remote Sensing
35032 Marburg
Germany
Individual:
Erwin Beck
Contact:
email:
erwin.beck <at> uni-bayreuth.de
Universitätsstr. 30
Faculty of Biology, Chemistry and Geoscience
University of Bayreuth
95440 Bayreuth
Germany
In tropical agriculture, the vigorously growing Bracken fern causes severe problems by<br/>
invading pastures and out-competing the common pasture grasses. Due to infestation by<br/>
that weed, pastures are abandoned after a few years, and as a fatal consequence, the biodi-<br/>
versity-rich tropical forest is progressively cleared for new grazing areas. Here we present a<br/>
broad physiological comparison of the two plant species that are the main competitors on<br/>
the pastures in the tropical Ecuadorian Andes, the planted forage grass Setaria sphacelata<br/>
and the weed Bracken (Pteridium arachnoideum).With increasing elevation, the competitive<br/>
power of Bracken increases as shown by satellite data of the study region. Using data<br/>
obtained from field measurements, the annual biomass production of both plant species, as<br/>
a measure of their competitive strength, was modeled over an elevational gradient from<br/>
1800 to 2800 m. The model shows that with increasing elevation, biomass production of the<br/>
two species shifts in favor of Bracken which, above 1800 m, is capable of outgrowing the<br/>
grass. In greenhouse experiments, the effects on plant growth of the presumed key vari-<br/>
ables of the elevational gradient, temperature and UV radiation, were separately analyzed.<br/>
Low temperature, as well as UV irradiation, inhibited carbon uptake of the C4-grass more<br/>
than that of the C3-plant Bracken. The less temperature-sensitive photosynthesis of<br/>
Bracken and its effective protection from UV radiation contribute to the success of the weed<br/>
on the highland pastures. In field samples of Bracken but not of Setaria, the content of flavo-<br/>
noids as UV-scavengers increased with the elevation. Combining modeling with measure-<br/>
ments in greenhouse and field allowed to explain the invasive growth of a common weed in<br/>
upland pastures. The performance of Setaria decreases with elevation due to suboptimal<br/>
photosynthesis at lower temperatures and the inability to adapt its cellular UV screen.
Keywords:
| South Ecuador | Bracken fern | competition |
Literature type specific fields:
ARTICLE
Journal:
PlosOne
Volume:
13
Page Range:
1-24
Metadata Provider:
Individual:
Jörg Bendix
Contact:
email:
bendix <at> staff.uni-marburg.de
Faculty of Geography
Deutschhausstraße 10
Philipps University of Marburg
Laboratory for Climatology and Remote Sensing
35032 Marburg
Germany
