Download the full-sized PDF of Fertilization effects on interactions between above-and belowground competition in an old fieldDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Biological Sciences, Department of


This file is in the following collections:

Journal Articles (Biological Sciences)

Fertilization effects on interactions between above-and belowground competition in an old field Open Access


Author or creator
Cahill, J. F.
Additional contributors
Asymmetric competition
Abutilon theophrasti
Root exclusion tubes
Positive interaction
Community organization
Shoot competition
Productivity gradient
Root competition
Nonadditive effects
Old field
Type of item
Journal Article (Published)
Recent theoretical and experimental studies have addressed whether the relative importance of aboveground and belowground competition changes along gradients of biomass productivity. Results have been contradictory, with some researchers finding a decrease in the importance of belowground competition and an increase in aboveground competition with increased productivity, and others finding either no relationship. or a positive correlation between the various factors. Belowground competitive intensity (BCI), resulting from root interactions, and total competitive intensity (TCI), resulting from both root and shoot interactions, have usually been measured as the proportional growth reduction due to competition (relative to growth without competition). Instead of direct measurement, aboveground competitive intensity (ACI) has been estimated by assuming that aboveground competition and belowground competition do not interact to affect plant growth, and therefore ACI + BCI = TCI. In this study, Abutilon theophrasti was used as a focal species to determine whether an interaction between the two competitive forms could exist. Target plants were grown with varying degrees of interaction with the roots of neighboring plants, through the use of modified root exclusion tubes, and by tying back the aboveground neighboring vegetation. In total, 16 combinations of varying intensities of aboveground and belowground interactions with neighbors were created at each of two fertilization levels. The strength of belowground competition decreased with fertilization, while neither aboveground competition nor total competition (occurring both above- and belowground simultaneously) varied among fertilization treatments. Not only was there evidence for an interaction between above- and belowground competition, the form of interaction varied with productivity, switching from no interaction in the unfertilized block to a positive interaction in the fertilized block. With fertilization, belowground competition decreased a plant's ability to compete in asymmetric competition for light. These results contrast with existing models of the role of competition in plant communities, and a new model is presented. In order to understand the rule of aboveground and belowground competition in plant communities, the potential for interactions between the two competitive forms must be considered in future studies.
Date created
License information
© 1999 Ecological Society of America. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.
Citation for previous publication
Cahill, J. F. (1999). Fertilization effects on interactions between above-and belowground competition in an old field. Ecology, 80(2), 466-480. DOI: 10.1890/0012-9658(1999)080[0466:FEOIBA]2.0.CO;2.
Link to related item

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 222736
Last modified: 2015:10:12 12:42:11-06:00
Filename: Ecology_80_1999_466.pdf
Original checksum: 37c3b192e776a66b89c276fda591100c
Well formed: true
Valid: true
File title: ecol_80_214.466_480
Page count: 15
Activity of users you follow
User Activity Date