新疆典型盐生植物营养器官盐分积累与生态化学计量特征

Salt accumulation in vegetative organs and ecological stoichiometry characteristics in typical halophytes in Xinjiang,China

对盐生植物体内器官盐分积累和碳(C)、氮(N)、磷(P)化学计量特征的研究,有助于了解盐生植物养分、盐分的分配机制和其对盐渍环境的适应策略。该文选择新疆4种典型的真盐生植物(3种灌木植物:盐节木(Halocnemum strobilaceum)、小叶碱蓬(Suaeda microphylla)、盐爪爪(Kalidium foliatum),1种草本植物:盐角草(Salicornia europaea)为研究对象,对比研究了它们的根、茎、叶中的盐分积累和C、N、P化学计量特征以及二者间的相关性。结果显示:1)在生长旺盛期,4种盐生植物体内盐分积累可形成"盐岛"效应(Na^+、Cl–和电导率随盐离子从植物根部向顶端运输过程呈显著增加的趋势)。2)4种盐生植物中灌木群落的生长主要受到P的限制;草本群落的生长受N和P(偏P)共同限制。3)器官、物种和二者的交互作用均能影响盐生植物的盐分(除Mg2^+外)特征和C、N、P生态化学计量特征。4)4种盐生植物C与N、P之间显著负相关,N与P之间显著正相关。5)盐生植物体内总盐分、Na^+和K^+与N、N:P之间呈显著正相关关系,与C、C:N、C:P之间呈显著负相关关系,而K^+和CO32–与P之间却显著正相关。盐生植物体内盐分和养分在应对盐渍环境上存在一定的相互促进关系,增施N肥有助于盐生植物对氯化物盐渍土的脱盐。这些发现为了解盐渍生境中盐生植物的生理生态适应及盐渍土的改良提供一定的理论依据。

Aims Studying salt accumulation in vegetative organs and carbon （C）, nitrogen （N）, phosphorus （P） stoichiome- try in halophytes contributes to understand the adaptive strategy to saline environment and the distribution mech- anism of nutrients and salinity of the halophytes.Methods Four typical dominant species, including three perennial shrubs （Halocnemum strobilaceum, Suaeda microphylla and Kalidiumfoliatum） and an annual herb （Salicornia europaea） were selected for analyzing the salt accumulation and C, N, P stoichiometry relationships.Important findings 1） The salt accumulation showed ＂salt island＂ effect at peak growing stage; Na＋, C1- and electrical conductivity all showed significant positive trends, when salt ions were transported from the root to the shoot of 4 halophytes. 2） P was the limiting growth element of perennial shrubs, while both N and P were limiting factors for the annual herb. 3） Different organs, species and their interactions affected C, N, P stoichiometry and salt icons except Mg2＋. 4） C was negatively correlated with N and P, but there was a significant positive correla- tion between N and E 5） Electrical conductivity, Na＋ and K＋ were positively correlated with N, N：P ratio, and negatively correlated with C, C：N and C：P ratios, and yet K＋, CO32 had significant positive correlation with E These results implied that there were some kind of mutual promoting relationships between nutrients and salinity in halophytes in the saline environment, and fertilizing with N could promote sodium chloride desalination.