几种藜科盐生植物吸盐能力及生态学意义

  【目的】  聚盐能力是评价盐生植物对盐碱地生物改良能力的一个重要参考指标。针对不同的盐碱地类型，有目的地选择生物量大且聚盐能力强的盐生植物，是实现盐碱地快速改良的关键。比较不同盐生植物的盐离子吸收类型及能力，可为盐碱地生物改良选择适宜的植物材料提供参考。  【方法】  试验选取7种藜科盐生植物进行人工种植试验，包括野榆钱菠菜(Atriplex aucheri)、高碱蓬(Suaeda altissima)、盐地碱蓬(Suaeda salsa)、盐角草(Salicornia europaea)、红叶藜(Chenopodium rubrum)、驼绒藜(Ceratoides latens)和四翅滨藜(Atriplex canescens)。试验地土壤以粉粘粒为主，根层土壤(0—40 cm)平均含盐量为45.57 g/kg。在生育末期采样测定植物地上部生物量和Na+、K+、Ca2+、Mg2+、Cl–、SO₄2–浓度。  【结果】  7种藜科植物地上部生物量为野榆钱菠菜(35077 kg/hm2)>盐地碱蓬(19507 kg/hm2)>高碱蓬(16160 kg/hm2)>驼绒藜(12421 kg/hm2)>四翅滨藜(10798 kg/hm2)>红叶藜(10134 kg/hm2)>盐角草(9576 kg/hm2)。高碱蓬、野榆钱菠菜、盐地碱蓬、盐角草和红叶藜5种植物组织内Na+、Cl–和SO₄2–浓度显著高于其他离子(P<0.05)，而驼绒藜和四翅滨藜体内K+、Cl–和Na+浓度较高。7种藜科植物地上部Na+、Cl–和SO₄2– 3种盐离子累积总量为野榆钱菠菜(3835 kg/hm2)>盐地碱蓬(3145 kg/hm2)>盐角草(2749 kg/hm2)>高碱蓬(2253 kg/hm2)>红叶藜(615 kg/hm2)>四翅滨藜(367 kg/hm2)>驼绒藜(220 kg/hm2)。  【结论】  盐生植物可在重度盐碱地上存活并产生一定的生物量，野榆钱菠菜、盐地碱蓬、盐角草和高碱蓬均表现出较强的吸盐能力，但对不同离子的吸收累积能力不同。盐地碱蓬地上部SO₄2–吸收量显著高于其他几种植物，适宜于硫酸盐或氯化物–硫酸盐盐渍土的改良；盐角草对Cl–表现出极强的吸收能力，适宜氯化物盐渍土的改良。

Salt absorption capacity and ecological significance of selected Chenopodiaceae halophytes

  【Objectives】  The salt accumulation ability of halophytes is one of the most important reference indexes for bioremediation of saline-alkali lands. The ion absorption types and abilities of different halophytes with large biomass were studied to provide a basis for selecting suitable plant materials in saline-alkali soil biological improvement.  【Methods】  Seven Chenopodiaceae halophytes were selected for artificial cultivation experiment in Karamay City, Xinjiang, including Atriplex aucheri, Suaeda altissima, Suaeda salsa, Salicornia europaea, Chenopodium rubrum, Ceratoides latens, and Atriplex canescens. The soil of the test site was silty clay by texture, had an average salt content of 45.57g/kg in the root layer (0?40 cm), which was categorized as severe saline alkali. The aboveground biomass and the concentrations of Na+, K+, Ca2+, Mg2+, Cl– and SO₄2– were measured at the end of growth.  【Results】  The above-ground dry biomass of the Chenopodiaceae plants were: Atriplex aucheri (35077 kg/hm2) >Suaeda salsa (19507 kg/hm2) > Suaeda altissima (16160 kg/hm2) >Ceratoides latens (12421 kg/hm2) > Atriplex canescens (10798 kg/hm2) > Chenopodium rubrum (10134 kg/hm2) > Salicornia europaea (9576 kg/hm2). In five of the plants - Suaeda altissima, Atriplex aucheri, Suaeda salsa, Salicornia europaea and Chenopodium rubrum, the concentrations of Na+, Cl– and SO₄2– were significantly higher than K+, Ca2+ (P<0.05), while in Atriplex canescens and Ceratoides latens, the concentrations of K+, Cl– and Na+ were higher than Ca2+, Mg2+. The total cumulative amount of Na+, Cl–and SO₄2– were 3835 kg/hm2 (Atriplex aucheri) >3145 kg/hm2 (Suaeda salsa) >2749 kg/hm2 (Salicornia europaea) >2253 kg/hm2 (Suaeda altissima) > 615 kg/hm2 (Chenopodium rubrum) >367 kg/hm2 (Atriplex canescens) > 220 kg/hm2(Ceratoides latens).  【Conclusions】  All the seven halophytes could survive in severe saline-alkali soil and produce ample biomass. However, among them, Atriplex aucheri, Suaeda salsa, Salicornia europaea and Suaeda altissima exhibited strong salt absorption abilities. Suaeda salsa accumulated significantly more SO₄2– in its aboveground part than other plants, hence was more suitable for the bioremediation of sulfate or chloride-sulfate saline soil. Salicornia europaea had a strong absorption capacity for Cl–, which rendered it more suitable for bioremediation of chloride saline soil.