J Plant Ecol ›› 2009, Vol. 2 ›› Issue (3): 119-124.doi: 10.1093/jpe/rtp012

• Research Articles • Previous Articles     Next Articles

Big plants—do they limit species coexistence?

Laura M. Keating and Lonnie W. Aarssen*   

  1. Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6
  • Received:2009-03-16 Accepted:2009-05-30 Online:2009-06-24 Published:2009-08-26
  • Contact: Aarssen, Lonnie E-mail:aarssenl@queensu.ca

Abstract: Aims According to conventional theory, larger plant species are likely to inflict more intense competition on other (smaller) species. We tested a deducible prediction from this: that a larger species should generally be expected to impose greater limits on the number of species that can coexist with it.
Methods Species richness was sampled under plant canopies for a selection of woody species ('host' species) that display a wide range of adult sizes (from small shrubs to large trees), growing within natural vegetation of the Interior Douglas-fir zone of southern British Columbia, Canada. These data were compared with species richness levels sampled within randomly placed plots within the host species habitat.
Important findings A prominent host species size effect on species richness was detected but only narrowly at the small end of the species size range. Across most (90%) of the increasing size range of host species, the number of species residing under the host canopy showed no significant decrease relative to the number expected by random assembly, based on species richness within randomly defined equivalent areas within the habitat of the host species. This apparent 'null effect', we suggest, is explained not because these larger species have no effect on community assembly. We postulate that larger species are indeed likely to be more effective in causing competitive exclusion of some smaller species (as expected from conventional theory), but that any potential limitation effect of this on resident species richness is offset for two reasons: (i) larger species also generate niche spaces that they cannot exploit under their own canopies and so have minimal impact (as competitors) on smaller species that can occupy these niches and (ii) certain other small species—despite small size—have effective competitive abilities under the severe competition that occurs within host neighbourhoods of larger species. These and other recent studies call for re-evaluation of traditional views on the role of plant size in affecting competitive ability and community assembly.

Key words: competition, competitive exclusion, plant size, physical space niche, random assembly, reproductive economy

摘要:
Aims According to conventional theory, larger plant species are likely to inflict more intense competition on other (smaller) species. We tested a deducible prediction from this: that a larger species should generally be expected to impose greater limits on the number of species that can coexist with it.
Methods Species richness was sampled under plant canopies for a selection of woody species ('host' species) that display a wide range of adult sizes (from small shrubs to large trees), growing within natural vegetation of the Interior Douglas-fir zone of southern British Columbia, Canada. These data were compared with species richness levels sampled within randomly placed plots within the host species habitat.
Important findings A prominent host species size effect on species richness was detected but only narrowly at the small end of the species size range. Across most (90%) of the increasing size range of host species, the number of species residing under the host canopy showed no significant decrease relative to the number expected by random assembly, based on species richness within randomly defined equivalent areas within the habitat of the host species. This apparent 'null effect', we suggest, is explained not because these larger species have no effect on community assembly. We postulate that larger species are indeed likely to be more effective in causing competitive exclusion of some smaller species (as expected from conventional theory), but that any potential limitation effect of this on resident species richness is offset for two reasons: (i) larger species also generate niche spaces that they cannot exploit under their own canopies and so have minimal impact (as competitors) on smaller species that can occupy these niches and (ii) certain other small species—despite small size—have effective competitive abilities under the severe competition that occurs within host neighbourhoods of larger species. These and other recent studies call for re-evaluation of traditional views on the role of plant size in affecting competitive ability and community assembly.

[1] Wei Xue, Lin Huang and Fei-Hai Yu. Importance of starting points in heterogeneous environments: interactions between two clonal plants with contrasting spatial architectures [J]. J Plant Ecol, 2020, 13(3): 323-330.
[2] Susanna Vain, Iris Gielen, Jaan Liira, and Kristjan Zobel. Population-level performance of Arabidopsis thaliana (L.) Heynh in dense monocultures [J]. J Plant Ecol, 2020, 13(2): 241-246.
[3] Yong Zhou, Xia Li, Hui Liu, Yubao Gao, Wade J. Mace, Stuart D. Card and Anzhi Ren. Effects of endophyte infection on the competitive ability of Achnatherum sibiricum depend on endophyte species and nitrogen availability [J]. J Plant Ecol, 2019, 12(5): 815-824.
[4] Ling-Yun Wan, Shan-Shan Qi, Chris B. Zou, Zhi-Cong Dai, Guang-Qian Ren, Qi Chen, Bin Zhu and Dao-Lin Du. Elevated nitrogen deposition may advance invasive weed, Solidago canadensis, in calcareous soils [J]. J Plant Ecol, 2019, 12(5): 846-856.
[5] Wagner A. Chiba de Castro, Rafael O. Xavier, Federico H. L. Garrido, Jair H. C. Romero, Cleto K. Peres and Ruberval C. da Luz. Fraying around the edges: negative effects of the invasive Tradescantia zebrina Hort. ex Bosse (Commelinaceae) on tree regeneration in the Atlantic Forest under different competitive and environmental conditions [J]. J Plant Ecol, 2019, 12(4): 713-721.
[6] Zhichun Lan, Yasong Chen, Lei Li, Feng Li, Binsong Jin and Jiakuan Chen. Testing mechanisms underlying elevational patterns of lakeshore plant community assembly in Poyang Lake, China [J]. J Plant Ecol, 2019, 12(3): 438-447.
[7] Robert J. Warren II, Matt Candeias, Adam Labatore, Michael Olejniczak and Lin Yang. Multiple mechanisms in woodland plant species invasion [J]. J Plant Ecol, 2019, 12(2): 201-209.
[8] Lina Weiss, Linda Schalow, Florian Jeltsch and Katja Geissler. Experimental evidence for root competition effects on community evenness in one of two phytometer species [J]. J Plant Ecol, 2019, 12(2): 281-291.
[9] Camilla Ruø Rasmussen, Anne Nygaard Weisbach, Kristian Thorup-Kristensen and Jacob Weiner. Size-asymmetric root competition in deep, nutrient-poor soil [J]. J Plant Ecol, 2019, 12(1): 78-88.
[10] Rebekka B?gelein, Cecilia A. Pérez, Philipp Sch?fer and Frank M. Thomas. How competitive is the ‘pioneerclimax’ tree species Nothofagus alpina in pristine temperate forests#br# of Chile? [J]. J Plant Ecol, 2019, 12(1): 144-156.
[11] Raquel Carolina Miatto and Marco Antonio Batalha.
Are the cerrado and the seasonal forest woody floras assembled by different processes despite their spatial proximity?
[J]. J Plant Ecol, 2018, 11(5): 740-750.
[12] Joseph K. Brown, Julie C. Zinnert, Donald R. Young. Emergent interactions influence functional traits and success of dune building ecosystem engineers [J]. J Plant Ecol, 2018, 11(4): 524-532.
[13] Benjamin D. Jaffe, Michael E. Ketterer, Stephen M. Shuster. Elemental allelopathy by an arsenic hyperaccumulating fern, Pteris vittata L. [J]. J Plant Ecol, 2018, 11(4): 553-559.
[14] Jaime Madrigal-González, Rodrigo S. Rios, Cristina F. Aragón, Ernesto Gianoli. Indirect facilitation by a liana might explain the dominance of a small tree in a temperate forest [J]. J Plant Ecol, 2018, 11(4): 604-612.
[15] Vasile Alexandru Suchar, Ronald Robberecht. Integration and scaling of UV-B radiation effects on plants: the relative sensitivity of growth forms and interspecies interactions [J]. J Plant Ecol, 2018, 11(4): 656-670.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!