Soil and Water Science Dep., Tropical Research and Education Center, Univ. of Florida, 18905 SW 280th St., Homestead, FL 33031, USA.
J Environ Qual. 2010 Sep-Oct;39(5):1585-93. doi: 10.2134/jeq2009.0461.
Dead plant tissues and ash from a prescribed fire play an important role in nutrient balance and cycling in the Florida Everglades ecosystem. The objective of this study was to assess the dynamic changes in total phosphorus release (TPr) from ash or tissues of either cattail (Typha domingensis Pers.) or sawgrass (Cladium jamaicense Crantz) to water. Natural-dead (senesced-dead) and burning-dead (standing-dead due to a prescribed fire) cattail and sawgrass were collected from highly (H) and moderately (M) impacted zones in the Florida Everglades. This experiment was conducted by incubation and water-extraction of the materials in plastic bottles for 65 d at room temperature (24 +/- 1 degrees C). Results showed that 63 to 88%, 17 to 48%, 9 to 20%, and 13 to 28% of total P (TPp) were released as TPr from cattail and sawgrass ash, cattail tissues from the H zone, cattail tissues, and sawgrass tissues from the M zone, respectively. TPp means total P of plant tissues, whereas TPr is total P release from the tissues or ash. Most of the TPr was released within 24 h after burning. The quick release of TPr observed in this experiment may help explain the P surge in the surface water immediately following a fire in the marsh. These findings suggest that prescribed burning accelerates P release from cattail and sawgrass. They also imply that it is very important to keep the water stagnant in the first 24 h to maximize the benefits of a prescribed fire in the Everglades.
死植物组织和规定火烧产生的灰烬在佛罗里达大沼泽地生态系统的养分平衡和循环中起着重要作用。本研究的目的是评估灰烬或黄菖蒲（Typha domingensis Pers.）或锯齿草（Cladium jamaicense Crantz）组织中总磷释放（TPr）从水到水中的动态变化。从佛罗里达大沼泽地的高（H）和中（M）受影响区采集天然死亡（衰老死亡）和燃烧死亡（因规定火灾而死亡）的黄菖蒲和锯齿草。该实验通过在室温（24 +/- 1 摄氏度）下将材料在塑料瓶中孵育和水提 65 天来进行。结果表明，黄菖蒲和锯齿草灰中 63%至 88%、17%至 48%、9%至 20%和 13%至 28%的总磷（TPp）分别以 TPr 的形式释放，H 区黄菖蒲灰、H 区黄菖蒲组织、M 区黄菖蒲组织和 M 区锯齿草组织。TPp 是指植物组织的总磷，而 TPr 是指组织或灰烬中总磷的释放量。大多数 TPr 在燃烧后 24 小时内释放。实验中观察到的 TPr 快速释放可能有助于解释火灾后沼泽地表水磷含量的激增。这些发现表明规定的燃烧加速了黄菖蒲和锯齿草中磷的释放。它们还暗示在大沼泽地，保持水在最初的 24 小时停滞是非常重要的，以最大限度地发挥规定火灾的好处。
