Natural and cultural eutrophication of Sluice Pond, Massachusetts, USA, recorded by algal and protozoan microfossils
Natural and cultural eutrophication of Sluice Pond, Massachusetts, USA, recorded by algal and protozoan microfossils
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藻类和原生动物微化石记录的美国马萨诸塞州水闸池的自然和文化富营养化
DOI：
10.1177/0959683614551227
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Brad Hubeny
中科院分区：
文献类型：
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作者：
Matea Drljepan;F. McCarthy;Brad Hubeny
对马萨诸塞州水闸塘的微体化石研究确定了影响藻类和原生动物群落的两种环境扰动：（1）由全新世中期干旱驱动的自然富营养化和水柱混合，（2）文化富营养化，增加底层水缺氧，以及伴随人类定居的毒性。SP 09 KC 2来自这个部分裂殖池塘的深盆，具有跨越11，400年的丰富多样的甲藻孢囊记录。底层水缺氧似乎阻止了底栖原生动物的殖民，直到湖泊水位下降整个新英格兰在全新世中期干旱。较低的湖面允许混合的水柱和thecamoebian动物丰富的centropyxids，Pontigulasia compressa，和Diflugia oblonga蓬勃发展的SP 09 KC 2。这个低位的标志是一个不整合，跨越中全新世铁杉最小（5400-3500 cal. BP）在SP 07 PC 4和增加营养物的水柱允许中营养-富营养甲藻类群（多甲藻cf. gatunense和Peridinium willei）以牺牲Peridinium wisconsinense而增加。上升的湖泊水位响应温暖，潮湿的气候记录的原生动物的丰度增加，耐受较低的溶解氧（DO）整个水闸池塘~2200卡尔。BP -泡囊变形虫Arcella vulgaris、Diflugia protaeiformis和Cucurbitella tricuspis以及纤毛Codonella cratera。随后的湖泊水位下降与晚全新世干旱允许一个多样化的thecamoebian社区蓬勃发展，直到大约300年前，当一个更强烈的富营养化阶段导致人类的影响。由于生化需氧量（BOD）的增加，底层水缺氧是由C。在沉积物中富含豚草花粉和其他杂草植物。在SP 07 PC 4的这段时间内，孢囊的峰值浓度反映了培养的富营养化，导致初级生产力高，溶解氧低，促进孢囊保存。表层沉积物中微体化石浓度低是由于溶解氧和毒性低。
Microfossil studies from Sluice Pond, Massachusetts, identified two environmental perturbations that impacted algal and protozoan communities: (1) natural eutrophication and water column mixing driven by the mid-Holocene drought and (2) cultural eutrophication, increasing bottom water anoxia, and toxicity accompanying human settlement. SP09 KC2 from the deep basin of this partially meromictic pond has an abundant and diverse record of dinoflagellate cysts spanning 11,400 years. Bottom water anoxia appears to have prevented benthic protozoans from colonizing until lake levels fell throughout New England during the mid-Holocene drought. Lower lake levels allowed mixing of the water column and a thecamoebian fauna rich in centropyxids, Pontigulasia compressa, and Difflugia oblonga to flourish in SP09 KC2. This lowstand is marked by an unconformity spanning the mid-Holocene hemlock minimum (5400–3500 cal. BP) in SP07 PC4 and by an increase in nutrients in the water column allowing mesotrophic–eutrophic dinoflagellate taxa (Peridinium cf. gatunense and Peridinium willei) to increase at the expense of Peridinium wisconsinense. Rising lake levels in response to the warm, wet climate are recorded by increasing abundances of protozoa tolerant of lower dissolved oxygen (DO) throughout Sluice Pond ~2200 cal. BP – the thecamoebians Arcella vulgaris, Difflugia protaeiformis, and Cucurbitella tricuspis and the ciliate Codonella cratera. Subsequent decline in lake level associated with late Holocene aridity allowed a diverse thecamoebian community to thrive until around 300 years ago when a more intense phase of eutrophication resulted from human impact. Bottom water anoxia due to enhanced biochemical oxygen demand (BOD) is recorded by the dominance of C. tricuspis in sediments rich in ragweed pollen and other weedy plants. Peak cyst concentrations in this interval in SP07 PC4 reflect cultural eutrophication leading to high primary productivity and low DO, promoting cyst preservation. Low microfossil concentrations in the surface sediments are attributed to low DO and toxicity.