Growth and allocation by a keystone wetland plant, <Emphasis Type="Italic">Panicum hemitomon</Emphasis>, and implications for managing and rehabilitating coastal freshwater marshes,Louisiana, USA |
| |
Authors: | C Ellery Mayence Mark W Hester |
| |
Institution: | (1) Department of Biological Sciences, Pontchartrain Institute for Environmental Science, University of New Orleans, New Orleans, LA 70148, USA;(2) Coastal Plant Ecology Laboratory, Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70506, USA;(3) CSIRO Plant Industry, Water for a Healthy Country Flagship, GPO Box 1600, Canberra, ACT, 2601, Australia |
| |
Abstract: | This paper attempts to establish linkages between growth by a keystone wetland plant, Panicum hemitomon Schultes, and the independent and interactive effect of nutrient and hydrologic regime to inform management and rehabilitation
of thick-mat floating marsh (TMFM). To do so a manipulative glasshouse experiment employing created TMFM similar to that under
consideration for field trials and two levels each of N, P and hydrology was conducted. P. hemitomon grew vigorously under saturated (flooding level with the surface of the mat) when compared to inundated (+15 cm flooding)
hydrologic conditions, and under enriched (50 g m−2 year−1) when compared to non-enriched (25 g m−2 year−1) N. Further, and as inferred from net CO2 assimilation, shoot biomass and rhizome biomass and length, N-enriched conditions seemed to lessen inundation stress. For
all variables the interaction between N and hydrology was non-significant and there was no observable effect of P. We were
unable to infer root or mat buoyancy from root specific gravity measurements but it was evident at harvest that saturation
or minimal flooding is required for vigorous root and rhizome growth. This study provides insight to the notion that decreased
mat buoyancy (and increased flooding level) resulting from sediment deposition associated with Mississippi River diversions
could adversely affect TMFM sustainability, but more clearly demonstrates the need to maintain saturated hydrologic conditions
for achieving the type of root and rhizome growth we feel is required for TMFM rehabilitation. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|