Silvertown, Jonathan; Araya, Yoseph N.; Linder, H. Peter and Gowing, David J.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/doi:10.1093/aob/mcs160|
|Google Scholar:||Look up in Google Scholar|
Background and aims Species in plant communities segregate along fine-scale hydrological gradients. Although
this phenomenon is not unique to fynbos, this community regenerates after fire and therefore provides an opportunity
to study the ecological genesis of hydrological niche segregation.
Methods Following wildfires at two field sites where we had previously mapped the vegetation and monitored the hydrology, seeds were moved experimentally in .2500 intact soil cores up and down soil-moisture gradients to test the hypothesis that hydrological niche segregation is established during the seedling phase of the life cycle. Seedling numbers and growth were then monitored and they were identified using DNA bar-coding, the first use of this technology for an experiment of this kind.
Key Results At the site where niche segregation among Restionaceae had previously been found, the size of seedlings was significantly greater, the wetter the location into which they were moved, regardless of the soil moisture status of their location of origin, or of the species. Seedling weight was also significantly greater in a competition treatment where the roots of other species were excluded. No such effects were detected at the control site where niche segregation among Restionaceae was previously found to be absent.
Conclusions The finding that seedling growth on hydrological gradients in the field is affected by soil moisture status and by root competition shows that hydrological niche segregation could potentially originate in the seedling stage. The methodology, applied at a larger scale and followed-through for a longer period, could be used to determine whether species are differently affected by soil moisture.
|Item Type:||Journal Article|
|Copyright Holders:||2012 The Author. Published by Oxford University Press on behalf of the Annals of Botany Company.|
|Funders:||Natural Environment Research Council|
|Keywords:||translocation experiment; seedling regeneration; fire; soil-moisture gradient; hydrological niche; root competition; DNA bar-coding; regeneration niche|
|Academic Unit/Department:||Science > Environment, Earth and Ecosystems|
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
OpenSpace Research Centre (OSRC)
|Depositing User:||Jonathan Silvertown|
|Date Deposited:||18 Jul 2012 15:15|
|Last Modified:||14 Nov 2012 10:11|
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