Does calcite encrustation in Chara provide a phosphorus nutrient sink?
We studied the effect of calcite encrustation in stoneworts (Chara spp.) on P cycling in an aquatic ecosystem. Sequential fractionation was performed to quantify P fractions of the internodes of calcified (Ca-CF) and uncalcified (UCa-CF) Chara fibrosa Agardh ex Bruzelius. Our results showed that Ca-CF was able to store more P and about 14 to 23% of total P in Ca-CF was co-precipitated with encrusted calcite, while only 2 to 3% was found in UCa-CF. Furthermore, in Ca-CF, an increased amount of total P did not result in a higher release of bioavailable water-soluble and sodium hydroxide-extractable P. Extracellular calcification in Chara enhanced nutrient sink for P, provided a further bottom-up control of phytoplankton, and should be regarded as a positive feedback in stabilizing Chara dominance in lakes.
Siong
Kian
K
Department of Environmental Science and Human Engineering, Saitama University, 255 Shimo-okubo, Sakura-Ku, Saitama 338-8570, Japan. 03D5052@post.saitama-u.ac.jp
Asaeda
Takashi
T
D002113:Calcification, Physiologic; D002118:Calcium / Q000032:analysis / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry; D044784:Chara; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry
D010758:Phosphorus; D002119:Calcium Carbonate; D002118:Calcium