Variation in hydraulic conductivity of mangroves: influence of species, salinity, and nitrogen and phosphorus availability
Variation in hydraulic conductivity of mangroves: influence of species, salinity, and nitrogen and phosphorus availability
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DOI：
10.1111/j.1399-3054.2006.00723.x
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发表时间：
2006-07
影响因子：
6.4
通讯作者：
C. Lovelock;M. Ball;I. Feller;Bettina M. J. Engelbrecht;Mei Ling Ewe
中科院分区：
文献类型：
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作者：
C. Lovelock;M. Ball;I. Feller;Bettina M. J. Engelbrecht;Mei Ling Ewe
我们研究了物种特性、盐度和养分有效性的变化如何影响红树林的水力传导性。利用佛罗里达州两个树种的施肥研究，我们发现以叶面积为基础表达的茎的导水率(K-叶)在不同耐盐性的树种之间存在显著差异，但不会因限制营养的增加而显著改变。回顾另外两个地点(巴拿马和伯利兹)的数据，我们发现了叶片特定导水率(K-叶子)随着盐度的增加而下降的总体模式。在三个地点上，出现了一个总体格局，表明当N限制生长时，当地茎的导水率(K-h)和K-叶对氮肥(N)的敏感性较低，而当P限制生长时，K-h和K叶对P(P)的敏感性较高。氮肥促进生长的过程可能与叶面积分配和光合作用过程的变化有关，而当磷限制生长时，水分吸收和运输过程可能更加有限。这些发现表明，虽然盐度和物种特性对水力传导性有很大的影响，但养分有效性的影响以复杂的方式调节了水力传导性和生长。
We investigated how species identity and variation in salinity and nutrient availability influence the hydraulic conductivity of mangroves. Using a fertilization study of two species in Florida, we found that stem hydraulic conductivity expressed on a leaf area basis (K-leaf) was significantly different among species of differing salinity tolerance, but was not significantly altered by enrichment with limiting nutrients. Reviewing data from two additional sites (Panama and Belize), we found an overall pattern of declining leaf-specific hydraulic conductivity (K-leaf) with increasing salinity. Over three sites, a general pattern emerges, indicating that native stem hydraulic conductivity (K-h) and K-leaf are less sensitive to nitrogen (N) fertilization when N limits growth, but more sensitive to phosphorus (P) fertilization when P limits growth. Processes leading to growth enhancement with N fertilization are probably associated with changes in allocation to leaf area and photosynthetic processes, whereas water uptake and transport processes could be more limiting when P limits growth. These findings suggest that whereas salinity and species identity place broad bounds on hydraulic conductivity, the effects of nutrient availability modulate hydraulic conductivity and growth in complex ways.