利用向量分析評估欖李苗木在不同土壤鹽度下之養分狀態

Using Vector Analysis to Assess the Nutrient Status of Lumnitzera racemosa Seedlings under Different Salinities

紅樹林樹種欖李（Lumnitzera racemosa）苗木以0、0.75、1.5、3.0、4.5 及6.0 % NaCl 等不同鹽度溶液，分別處理60、90 及120 天。而此三個取樣時期的苗木生長情形相似，因此僅以第120 天的資料，利用向量分析（vector analysis）評估不同土壤鹽度對苗木養分狀態之影響。結果顯示欖李苗木在0.75 % 鹽度中生長最佳，1.5 % 鹽度處理之葉片雖呈濃綠健康狀態，但苗木生長已受抑制。而診斷分析結果顯示，生長於0.75 及1.5 % 鹽度之苗木，其葉片Na 及Cl 離子濃度明顯缺乏，仍不足以供滲透調節作用進行。葉片K、N、Mg 及Ca 則呈現生長稀釋之影響，因此不會影響此二種鹽度對苗木之生長。至於3.0 % 鹽度已明顯抑制苗木生長，4.5 及6.0 % 處理之苗木則在處理後期逐漸死亡。而診斷分析結果證實，苗木若生長在超過3.0 % 以上之高鹽分環境時，苗木會過量吸收Na 及Cl 離子導致毒害；而且葉片之N、Mg、K 及Ca 離子濃度，則因Na 及Cl 離子過量累積而呈現拮抗作用。 Mangrove seedlings Lumnitzera racemosa were grown in different concentrations of salinity containing 0, 0.75, 1.5, 3.0, 4.5 and 6.0% NaCl for periods of 60, 90 and 120 days. The variable trends of three harvest periods were markedly similar, therefore only the data for the 120 days harvest were presented. The application of vector analysis to assess nutrient status of seedlings under different salinities was studied. Seedling growth was significantly stimulated in 0.75% NaCl treatment, but inhibited in 1.5% NaCl treatment, although the leaves appeared both green and healthy. Diagnosis results indicated that seedlings grown in 0.75 and 1.5% NaCl displayed a significant deficiency for osmoregulation required Na and Cl ions. The K, N, Mg and Ca nutrients in the leaves displayed dilution effects that did not inhibit the growth of seedlings for both salinity treatments. Seedlings grown in a concentration of 3.0% NaCl were significantly suppressed, and seedlings grown in concentrations of 4.5 and 6.0% NaCl died by the end of the experiment. Diagnostic results confirmed that seedlings grown in hypersaline conditions of more than 3.0% NaCl salinity expressed an excessive uptake of Na and Cl ions, resulting in a toxicity for the seedlings. The N, Mg, K and Ca ions in the leaves also displayed antagonistic effects that due to an excess accumulation of Na and Cl ions.

Mangrove seedlings Lumnitzera racemosa were grown in different concentrations of salinity containing 0, 0.75, 1.5, 3.0, 4.5 and 6.0% NaCl for periods of 60, 90 and 120 days. The variable trends of three harvest periods were markedly similar, therefore only the data for the 120 days harvest were presented. The application of vector analysis to assess nutrient status of seedlings under different salinities was studied. Seedling growth was significantly stimulated in 0.75% NaCl treatment, but inhibited in 1.5% NaCl treatment, although the leaves appeared both green and healthy. Diagnosis results indicated that seedlings grown in 0.75 and 1.5% NaCl displayed a significant deficiency for osmoregulation required Na and Cl ions. The K, N, Mg and Ca nutrients in the leaves displayed dilution effects that did not inhibit the growth of seedlings for both salinity treatments. Seedlings grown in a concentration of 3.0% NaCl were significantly suppressed, and seedlings grown in concentrations of 4.5 and 6.0% NaCl died by the end of the experiment. Diagnostic results confirmed that seedlings grown in hypersaline conditions of more than 3.0% NaCl salinity expressed an excessive uptake of Na and Cl ions, resulting in a toxicity for the seedlings. The N, Mg, K and Ca ions in the leaves also displayed antagonistic effects that due to an excess accumulation of Na and Cl ions.