Monday, November 5, 2007
92-10
Growth of Bald Cypress [Taxodium Distichum (L.) Rich] Seedlings in the Tidal Floodplain of the Loxahatchee River.
Abstract
This study was carried out from February 2005 to December 2005. Our goal was to elucidate the seasonal growth dynamics of bald cypress seedlings. Eight 1-m2 plots were established in Sites 1 and 2 within the tidal floodplains of the Northwest Fork of the river. Seedling heights in the plots were measured 9 times at approximately 30-days intervals. Simultaneously, soil samples were collected 9 times just outside the plots and their electrical conductivity (EC) values were determined. Seedling growth rates were found to be slow during either early February to early March or mid-July to mid-December; however, the growth rates were rapid during early March through mid-July. Incremental increases of the seedling heights over time followed a sigmoid curve and could be well fitted in a logistic equation with a R2 of greater than 0.99. The EC level of soil at Site 1 was always greater than at Site 2 except on the dates of March 4, and November 4, 2005. Conversely, the growth rate of the seedlings at Site 2 was significantly greater than that at Site 1. The maximum growth rates in 2005 were 1.75 and 2.68 mm/day at Sites 1 and 2, respectively. The growth rates were 80% or more of the maximum when the EC levels ranged from 0.54 to 0.65 dS/m at Site 1 and 0.32 to 0.48 dS/m for Site 2. This growth analyses provided a basis for water resources management and freshwater plant community restoration in theLoxahatchee River floodplain.
This study was carried out from February 2005 to December 2005. Our goal was to elucidate the seasonal growth dynamics of bald cypress seedlings. Eight 1-m2 plots were established in Sites 1 and 2 within the tidal floodplains of the Northwest Fork of the river. Seedling heights in the plots were measured 9 times at approximately 30-days intervals. Simultaneously, soil samples were collected 9 times just outside the plots and their electrical conductivity (EC) values were determined. Seedling growth rates were found to be slow during either early February to early March or mid-July to mid-December; however, the growth rates were rapid during early March through mid-July. Incremental increases of the seedling heights over time followed a sigmoid curve and could be well fitted in a logistic equation with a R2 of greater than 0.99. The EC level of soil at Site 1 was always greater than at Site 2 except on the dates of March 4, and November 4, 2005. Conversely, the growth rate of the seedlings at Site 2 was significantly greater than that at Site 1. The maximum growth rates in 2005 were 1.75 and 2.68 mm/day at Sites 1 and 2, respectively. The growth rates were 80% or more of the maximum when the EC levels ranged from 0.54 to 0.65 dS/m at Site 1 and 0.32 to 0.48 dS/m for Site 2. This growth analyses provided a basis for water resources management and freshwater plant community restoration in the
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