地球化学
地毬化學
지구화학
GEOCHIMICA
2014年
4期
365-374
,共10页
赵宁%杨旸%高建华%刘毅飞%蔡廷禄%贾建军
趙寧%楊旸%高建華%劉毅飛%蔡廷祿%賈建軍
조저%양양%고건화%류의비%채정록%가건군
稳定碳氮同位素%大叶藻%海洋藻类%有机质%月湖
穩定碳氮同位素%大葉藻%海洋藻類%有機質%月湖
은정탄담동위소%대협조%해양조류%유궤질%월호
stable carbon/nitrogen isotope%Eelgrass (Zostera marina)%Marine algae%Organic matter%Yuehu Lagoon
潟湖海湾可以保存环境演化和人类活动的良好记录,碳氮元素含量及同位素特征可用来有效地反演这些演化。对位于山东半岛的月湖柱状样和沿岸表层样总有机碳、总氮、稳定碳氮同位素的分析表明,陆源物质对月湖沉积物和有机质的贡献很小,其沉积物中有机质的主要来源是维管植物大叶藻和各种海洋藻类。在2002年前大约140 a的沉积历史中,大叶藻对沉积物有机质的贡献比例呈上升趋势,其中在约1930年和1980年有两次明显的上升,前者可能因为种群的快速繁育,后者则可能是1979年口门筑坝后由于湾内环境恶化,大叶藻开始大量死亡的表现。月湖海洋藻类的有机碳埋藏通量在沉积记录中保持相对稳定,而大叶藻则增加了一倍,但两者都有一定程度的波动。研究结果表明自然环境演变(如沙嘴生长、口门缩小)和人类活动(如筑坝、修筑虾池)对月湖生态环境及有机碳埋藏的影响在沉积物中有清晰的记录。
潟湖海灣可以保存環境縯化和人類活動的良好記錄,碳氮元素含量及同位素特徵可用來有效地反縯這些縯化。對位于山東半島的月湖柱狀樣和沿岸錶層樣總有機碳、總氮、穩定碳氮同位素的分析錶明,陸源物質對月湖沉積物和有機質的貢獻很小,其沉積物中有機質的主要來源是維管植物大葉藻和各種海洋藻類。在2002年前大約140 a的沉積歷史中,大葉藻對沉積物有機質的貢獻比例呈上升趨勢,其中在約1930年和1980年有兩次明顯的上升,前者可能因為種群的快速繁育,後者則可能是1979年口門築壩後由于灣內環境噁化,大葉藻開始大量死亡的錶現。月湖海洋藻類的有機碳埋藏通量在沉積記錄中保持相對穩定,而大葉藻則增加瞭一倍,但兩者都有一定程度的波動。研究結果錶明自然環境縯變(如沙嘴生長、口門縮小)和人類活動(如築壩、脩築蝦池)對月湖生態環境及有機碳埋藏的影響在沉積物中有清晰的記錄。
석호해만가이보존배경연화화인류활동적량호기록,탄담원소함량급동위소특정가용래유효지반연저사연화。대위우산동반도적월호주상양화연안표층양총유궤탄、총담、은정탄담동위소적분석표명,륙원물질대월호침적물화유궤질적공헌흔소,기침적물중유궤질적주요래원시유관식물대협조화각충해양조류。재2002년전대약140 a적침적역사중,대협조대침적물유궤질적공헌비례정상승추세,기중재약1930년화1980년유량차명현적상승,전자가능인위충군적쾌속번육,후자칙가능시1979년구문축패후유우만내배경악화,대협조개시대량사망적표현。월호해양조류적유궤탄매장통량재침적기록중보지상대은정,이대협조칙증가료일배,단량자도유일정정도적파동。연구결과표명자연배경연변(여사취생장、구문축소)화인류활동(여축패、수축하지)대월호생태배경급유궤탄매장적영향재침적물중유청석적기록。
Information of environmental changes and human activities can be preserved in lagoon sediments potentially, and reconstructed through the analyses of concentration and isotopic composition of carbon and nitrogen in organic matter. The Yuehu Lagoon, located in the Rongcheng Bay at the eastern tip of Shandong Peninsula, is a small lagoon-tidal inlet system. Our work on a sediment core in the lagoon and 18 near-shore surface sediment samples indicates that the organic matter in the lagoon sediments is mainly sourced from eelgrass (Zostera marina) and marine algae, with negligible terrestrial input. The results of carbon, nitrogen element and isotope analyses show that the contribution of eelgrass kept increasing in the past ~140 years before 2002, especially in two periods of around 1930 and near 1980. The former increasing might be resulted from the prosperity of eelgrass;the latter was probably caused by the massive death of eelgrass after the dam construction near the lagoon mouth in 1979 that deteriorated the lagoon environment significantly. Compared with the relatively stable organic carbon burial flux of marine algae, that of eelgrass increased about two-fold, but both had some fluctuations. Therefore, the influences of natural evolution (e.g., the growth of sandspit) and human activities (e.g., the dam construction) on ecological environment and organic carbon burial are clearly recorded in the sediments of Yuehu Lagoon.