Sap flow characteristics of neotropical mangroves in flooded and drained soils.
Sap flow characteristics of neotropical mangroves in flooded and drained soils.
复制标题
DOI：
10.1093/treephys/27.5.775
复制
发表时间：
2007-05
期刊：
影响因子：
4
通讯作者：
K. Krauss;P. Young;J. L. Chambers;T. Doyle;R. Twilley
中科院分区：
文献类型：
--
作者：
K. Krauss;P. Young;J. L. Chambers;T. Doyle;R. Twilley
洪水对红树林水运的影响以前已经在一些研究中进行了调查，其中大多数是在受控环境下对幼苗进行的。在这项研究中，我们使用热耗散液探针来确定液流（J(s)）是否随着径向深度进入生长在Rookery Bay的三种南佛罗里达红树林成熟树木的木质部而衰减。这是通过在多个深度插入液体探针并监测日流量来实现的。对于大多数被测树种和直径级组合，J(s)在径向深度超过2或4 cm时急剧下降，超过6 cm时几乎没有液流。Avicennia germinans （L.）平均J(s)降低了20%。斯登，总状拉孔菌（L.）Gaertn。f.土壤淹水时，根霉（Rhizophora mangle L.）树木。种间差异非常显著，在径向深度为2cm处，总状藓的正午J(s)最大，约为26 g H(2)O m(-2) s(-1)，而其他两种的平均值约为15 g H(2)O m(-2) s（-1）。红树林在2厘米深度的液流与其他森林湿地树种报告的速率相当。结果表明：(1)盆地红树林早春淹水导致成熟红树林树液流减少；(2) J(s)沿径向剖面的急剧衰减对理解红树林全树水分利用策略具有重要意义；(3)无论洪水状态如何，红树林个体水分利用遵循叶片水平的保守机制。
Effects of flooding on water transport in mangroves have previously been investigated in a few studies, most of which were conducted on seedlings in controlled settings. In this study, we used heat-dissipation sap probes to determine if sap flow (J(s)) attenuates with radial depth into the xylem of mature trees of three south Florida mangrove species growing in Rookery Bay. This was accomplished by inserting sap probes at multiple depths and monitoring diurnal flow. For most species and diameter size class combinations tested, J(s) decreased dramatically beyond a radial depth of 2 or 4 cm, with little sap flow beyond a depth of 6 cm. Mean J(s) was reduced on average by 20% in Avicennia germinans (L.) Stearn, Laguncularia racemosa (L.) Gaertn. f. and Rhizophora mangle L. trees when soils were flooded. Species differences were highly significant, with L. racemosa having the greatest midday J(s) of about 26 g H(2)O m(-2) s(-1) at a radial depth of 2 cm compared with a mean for the other two species of about 15 g H(2)O m(-2) s(-1). Sap flow at a depth of 2 cm in mangroves was commensurate with rates reported for other forested wetland tree species. We conclude that: (1) early spring flooding of basin mangrove forests causes reductions in sap flow in mature mangrove trees; (2) the sharp attenuations in J(s) along the radial profile have implications for understanding whole-tree water use strategies by mangrove forests; and (3) regardless of flood state, individual mangrove tree water use follows leaf-level mechanisms in being conservative.