J Plant Ecol ›› 2010, Vol. 3 ›› Issue (2): 99-108 .DOI: 10.1093/jpe/rtq003

• Research Articles • Previous Articles     Next Articles

Biodiversity and belowground interactions mediate community invasion resistance against a tall herb invader

Christoph Scherber1,*, Peter N. Mwangi2,3,4, Martin Schmitz2,3,4, Michael Scherer-Lorenzen5, Holger Beßler6, Christof Engels6, Nico Eisenhauer7, Varvara D. Migunova8, Stefan Scheu7, Wolfgang W. Weisser4, Ernst-Detlef Schulze3 and Bernhard Schmid2   

  1. 1 Agroecology, Department of Crop Science, University of Göttingen, Waldweg 26, D-37073 Göttingen, Germany; 2 Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstraße 92, CH-8057 Zurich, Switzerland; 3 Max Planck Institute for Biogeochemistry, Hans-Knoll Straße 10, D-07745 Jena, Germany; 4 Institute of Ecology, Jena University, Dornburger Straße 159, D-07743 Jena, Germany; 5 Institut für Biologie II/Geobotanik, Schänzlestr. 1, D-79104 Freiburg, Germany; 6 Humboldt Universität zu Berlin, Fachgebiet Pflanzenernährung, Albrecht-Thaer-Weg 4, D-14195 Berlin, Germany; 7 J.F. Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Berliner Str. 28, D-37073 Göttingen, Germany; 8 K.I. Skryabin All-Russian Institute of Helminthology, Bolschaya Tcheryomuschkinskaya str. 28, 117218 Moscow, Russia
  • Received:2009-09-05 Accepted:2010-02-08 Published:2010-05-26
  • Contact: Scherber, Christoph

Biodiversity and belowground interactions mediate community invasion resistance against a tall herb invader

Abstract: Aims Species-rich plant communities are hypothesized to be more resistant against plant invasions because they use resources in a more efficient way. However, the relative contributions of aboveground competition and belowground interactions for invasion resistance are still poorly understood.
Methods We compared the performance of Knautia arvensis transplants growing in plots differing in plant diversity both under full competition and with shoots of neighbors tied back to determine the relative strength of aboveground competition in suppressing this test invader without the confounding effect of shading. In addition, we assessed the effects of belowground competition and soil-borne pathogens on transplant performance.
Important findings Both aboveground competition and plant species richness strongly and independently affected invader performance. Aboveground biomass, height, leaf mass per area and flowering of transplanted individuals of K. arvensis decreased with increasing species richness of the host community. Species-rich and species-poor communities both imposed equally strong aboveground competition on K. arvensis. However, belowground interactions (especially belowground root competition) had strong negative effects on transplant performance. In addition, the presence of grasses in a plant community further reduced the performance of K. arvensis. Our results suggest that belowground competition can render species-rich host communities more suppressive to newly arriving species, thus enhancing community invasion resistance.

Key words: aboveground competition, competitive suppression, belowground interactions, root competition, shoot exclusion, species richness

摘要:
Aims Species-rich plant communities are hypothesized to be more resistant against plant invasions because they use resources in a more efficient way. However, the relative contributions of aboveground competition and belowground interactions for invasion resistance are still poorly understood.
Methods We compared the performance of Knautia arvensis transplants growing in plots differing in plant diversity both under full competition and with shoots of neighbors tied back to determine the relative strength of aboveground competition in suppressing this test invader without the confounding effect of shading. In addition, we assessed the effects of belowground competition and soil-borne pathogens on transplant performance.
Important findings Both aboveground competition and plant species richness strongly and independently affected invader performance. Aboveground biomass, height, leaf mass per area and flowering of transplanted individuals of K. arvensis decreased with increasing species richness of the host community. Species-rich and species-poor communities both imposed equally strong aboveground competition on K. arvensis. However, belowground interactions (especially belowground root competition) had strong negative effects on transplant performance. In addition, the presence of grasses in a plant community further reduced the performance of K. arvensis. Our results suggest that belowground competition can render species-rich host communities more suppressive to newly arriving species, thus enhancing community invasion resistance.