黄河三角洲新生湿地不同生境下翅碱蓬锰和锌含量的季节变化

锰和锌元素是植物生长所必须的微量元素,对植物的光合作用和氮的代谢起到重要的影响;锌元素还与植物生长素——吲哚乙酸的合成息息相关,锰元素则能够调节植物体内氧化还原状况,是盐生植物适应环境不可缺少的元素。于2008年5～11月,在黄河三角洲新生湿地不同生境下,对翅碱蓬(Suaeda salsa)的锰和锌含量与累积的季节变化特征进行了研究。结果表明,中潮滩翅碱蓬和低潮滩翅碱蓬的锰和锌含量分布存在明显差异,中潮滩翅碱蓬不同器官的锌含量都大于低潮滩翅碱蓬,而低潮滩翅碱蓬除了根的锰含量小于中潮滩翅碱蓬外,其他器官的锰含量都大于中潮滩翅碱蓬;二者不同器官的锰和锌含量都具有明显季节变化,其变化模式虽存在一定差异,但整体上都表现为生长初期锰和锌含量较低,之后波动增加;二者枯落物的锰含量变化较为一致,但锌含量差异显著(p<0.05);尽管中潮滩翅碱蓬与低潮滩翅碱蓬不同部位的锰和锌含量间的相关性都未达到显著水平,但不同表现型植被间差异较大,原因可能与其生理生态结构以及对锰和锌元素吸收与利用程度的差异有关。中潮滩翅碱蓬、低潮滩翅碱蓬不同部位的锰和锌储量亦具有明显季节变化,且其变化模式大多符合Gauss曲线;在翅碱蓬生长阶段,根为中潮滩翅碱蓬锰和锌元素的主要储库,其含量分别为(26.23±5.43)%和(2.84±1.06)%;根也为低潮滩翅碱蓬锌元素的主要储库,其含量为(19.58±10.95)%;而茎为低潮滩翅碱蓬锰元素的主要储库,其含量为(42.09±4.08)%。二者枯落物中锰和锌储量,特别是锌储量,所占比例很高,这可能与翅碱蓬生长末期,其地上不同器官中残存的大量锰和锌元素,在其死亡前因移动性较差而无法大量转移有关。研究发现,中潮滩翅碱蓬、低潮滩翅碱蓬不同部位锰和锌含量和储量的变化及差异主要与其生态学特性、不同器官营养功能以及所处生境的水盐状况有关。

Seasonal Changes of Manganese and Zinc Contents in Suaeda salsa in Different Growth Conditions of the New-born Wetlands in the Yellow River Delta

Manganese and zinc are the necessary microelements,which play an important role for photosynthesis and nitrogen metabolism.Besides,zinc relates to the synthetization of the indolylacetic acid,while manganese can adjust oxidation-deoxidation status in plant.They are the absolutely necessary element for halophyte. So from May to November in 2008,the seasonal changes of manganese and zinc contents and their accumulation of Suaeda salsa in different growth conditions of the new-born wetlands in the Yellow River Estuary were studied.Results showed that the manganese and zinc contents in different organs of Suaeda salsa in the middle and low tidal flats showed significantly different,and the zinc content of Suaeda salsa in the middle tidal flat was much higher than that of Suaeda salsa in the low tidal flat,but the values of manganese contents were opposite except for the root of Suaeda salsa in the low tidal flat.The manganese and zinc contents of Suaeda salsa in different growth conditions had significantly seasonal change.In general,the manganese and zinc contents were significantly smaller at the initial stage of plant growth,and then increased at all times although some fluctuations were existed in some periods.The manganese and zinc contents in litter also had significantly seasonal change,and the manganese content of Suaeda salsa in the middle and low tidal flats had the similar trend,while the zinc contents of Suaeda salsa between the middle and low tidal flats had significant difference(p<0.05).The manganese and zinc storage in different parts also had significantly seasonal change,and most of them were accorded with Gauss curve.In growth period,root was the main depository of manganese and zinc in Suaeda salsa in the middle tidal flat(the proportions were(26.23±5.43)%and(2.84±1.06)%,respectively)and the main zinc depository((19.58±10.95)%)in Suaeda salsa in the low tidal flat,while stem was the main depository of manganese in Suaeda salsa in the middle tidal flat,and the proportion was (42.09±4.08)%.The percentages of manganese and zinc storage,especially zincstorage,in the litter were very high,which were related to the poor mobility of manganese and zinc in aboveground parts at the end of period of the plant growth.