Sherman Ruth E, Fahey Timothy J, Howarth Robert W
Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY 14853, USA Fax: (607) 255-0349; e-mail:
Section of Ecology and Systematics, Division of Biological Sciences, Corson Hall, Cornell University, Ithaca, NY 14853, USA, , , , , , US.
Oecologia. 1998 Jul;115(4):553-563. doi: 10.1007/s004420050553.
We examined soil porewater concentrations of sulfate, alkalinity, phosphorus, nitrogen, and dissolved organic carbon and solid phase concentrations of pyrite in relation to mangrove species distributions along a 3.1-km-long transect that traversed a 47.1-km mangrove forest in the Dominican Republic. Iron, phosphorus, and sulfur dynamics are closely coupled to the activity of sulfate-reducing bacteria, the primary decomposers in anoxic soils of mangrove ecosystems. Patterns in the chemistry data suggested that sulfate reduction rates and storage of reduced sulfur were greater in the inland basin forest dominated by Laguncularia racemosa than the Rhizophora mangle dominated forest of the lower tidal region. The distribution of Laguncularia was significantly correlated with concentrations of total phosphorus (r= 0.99) and dissolved organic carbon (r= 0.86), alkalinity (r= 0.60), and the extent of sulfate depletion (r= 0.77) in the soil porewater and soil pyrite concentrations (r= 0.72) across the tidal gradient. Leaf tissue chemistry of Laguncularia was characterized by lower C:N and C:P ratios that could fuel the higher rates of decomposition in the Laguncularia-dominated forest. We suggest that a plant-soil-microbial feedback contributes to the spatial patterning of vegetation and soil variables across the intertidal zone of many mangrove forest communities.
我们沿着一条3.1公里长的样带，研究了硫酸盐、碱度、磷、氮和溶解有机碳的土壤孔隙水浓度以及黄铁矿的固相浓度，该样带横穿多米尼加共和国一片47.1公里长的红树林。铁、磷和硫的动态与硫酸盐还原细菌的活性密切相关，硫酸盐还原细菌是红树林生态系统缺氧土壤中的主要分解者。化学数据模式表明，在内陆盆地以拉贡古里亚红树为主的森林中，硫酸盐还原率和还原硫的储存量高于低潮区以红树为主的森林。在潮汐梯度上，拉贡古里亚红树的分布与土壤孔隙水中总磷浓度（r = 0.99）、溶解有机碳浓度（r = 0.86）、碱度（r = 0.60）、硫酸盐消耗程度（r = 0.77）以及土壤黄铁矿浓度（r = 0.72）显著相关。拉贡古里亚红树的叶片组织化学特征是较低的C:N和C:P比，这可能导致以拉贡古里亚红树为主的森林中更高的分解速率。我们认为，植物-土壤-微生物反馈有助于许多红树林群落潮间带植被和土壤变量的空间格局形成。
