Record ID No. |
1972 |
Author(s) |
Euliss A.C., Fisk M.C., McCleneghan S.C., Neufeld H.S , 2007 |
Affiliation |
Appalachian State University, Department of Biology, Boone,NC 28608 USA |
Title |
Allocation and morphological responses to resource manipulations are unlikely to mitigate shade intolerance in Houstonia montana, a rare southern Appalachian herb |
Source. Vol.(no):Page |
Canadian Journal of Botany.85(10):976-985p. |
Categories |
Mycorrhiza General |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
United States |
Abstracts |
High light requirements limit the distribution of several rare plant species
endemic to the southern Appalachian region. We studied the influence of light and nitrogen
availability on carbon allocation and morphology in one of these species, Houstonia montana
Small. Insights into growth and nutrition of H. Montana are needed for predicting how it will
respond to ongoing changes in its environment associated with atmospheric nitrogen deposition and
resulting from succession and (or) management of grassy-bald habitats in which it occurs. We
hypothesized that low light constrains belowground allocation, and that elevated N availability
reduces limitations to aboveground growth at low light. We tested growth and mycorrhizal
colonization of H. Montana in response to interactions of light and N availability in a
greenhouse experiment. Shade reduced plant biomass, root:shoot ratios, and mycorrhizal
colonization, and increased specific leaf area (area/mass). Elevated N reduced root:shoot ratios
and mycorrhizal colonization. Under low light, N addition increased specific root length
(length/mass) and foliar chlorophyll. We found support for the hypotheses that low light and high
N reduce belowground allocation in H. Montana. However, we did not find that high N significantly
alleviates limitation to plant growth in the shade, despite changes in allocation, morphology,
and chemistry that were consistent with more efficient use of C for aboveground growth. Thus,
variation in the soil N availability is unlikely to have a marked effect on the ability of H.
Montana to tolerate shade in its native habitat. |