{"title":"Fragmentation and separation of diatom valves in modern shallow lake sediments: a case study in Lake Kitaura, Japan","authors":"Kento Kumisaka, Naofumi Yamaguchi, Yusuke Okazaki","doi":"10.1007/s10933-024-00332-0","DOIUrl":null,"url":null,"abstract":"<p>We investigated diatom-valve fragmentation and frustule separation in surface sediments in Lake Kitaura, a shallow lake in Japan, to clarify how sedimentation processes affect diatom assemblages. Twenty-two surface-sediment samples were collected from Lake Kitaura in 2014. <i>Aulacoseira</i> spp. were characteristic planktonic taxa, and <i>Cocconeis placentula</i> and <i>Planothidium lanceolatum</i> were characteristic benthic taxa, both with monoraphid valves. The fragmentation ratios of <i>Aulacoseira</i> spp., the most abundant taxon, were higher nearshore than in the central part of the lake. <i>Cocconeis placentula</i>, an epiphytic species, was widely distributed in Lake Kitaura, and its fragmentation ratios increased with distance from the lakeshore. The coexistence ratios of the two valve types of this species decreased with distance from the lakeshore and from macrophytic vegetation. <i>Planothidium lanceolatum</i>, a fluvial benthic species, was abundant at the three northernmost sites near a river mouth, and the frustules of this species were seldom separated. These results suggest that long-distance transport promotes fragmentation and separation of benthic diatom valves in shallow lakes.</p>","PeriodicalId":16658,"journal":{"name":"Journal of Paleolimnology","volume":"13 1","pages":""},"PeriodicalIF":1.7000,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Paleolimnology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1007/s10933-024-00332-0","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
We investigated diatom-valve fragmentation and frustule separation in surface sediments in Lake Kitaura, a shallow lake in Japan, to clarify how sedimentation processes affect diatom assemblages. Twenty-two surface-sediment samples were collected from Lake Kitaura in 2014. Aulacoseira spp. were characteristic planktonic taxa, and Cocconeis placentula and Planothidium lanceolatum were characteristic benthic taxa, both with monoraphid valves. The fragmentation ratios of Aulacoseira spp., the most abundant taxon, were higher nearshore than in the central part of the lake. Cocconeis placentula, an epiphytic species, was widely distributed in Lake Kitaura, and its fragmentation ratios increased with distance from the lakeshore. The coexistence ratios of the two valve types of this species decreased with distance from the lakeshore and from macrophytic vegetation. Planothidium lanceolatum, a fluvial benthic species, was abundant at the three northernmost sites near a river mouth, and the frustules of this species were seldom separated. These results suggest that long-distance transport promotes fragmentation and separation of benthic diatom valves in shallow lakes.
期刊介绍:
The realization that a historical perspective is often useful, if not essential, to the understanding of most limnological processes has resulted in the recent surge of interest in paleolimnology. The main aim of the Journal of Paleolimnology is the provision of a vehicle for the rapid dissemination of original scientific work dealing with the reconstruction of lake histories. Although the majority of papers deal with lakes, paleoenvironmental studies of river, wetland, peatland and estuary systems are also eligible for publication.
The Journal of Paleolimnology, like the subject itself, is multidisciplinary in nature, and papers are published that are concerned with all aspects (e.g. biological, chemical, physical, geological, etc.) of the reconstruction and interpretation of lake histories. Both applied and more theoretical papers are equally encouraged. The Journal of Paleolimnology will continue to be a major repository for papers dealing with climatic change, as well as other pressing topics, such as global environmental change, lake acidification, eutrophication, long-term monitoring, and other aspects of lake ontogeny. Taxonomic and methodological papers are also acceptable provided they are of relatively broad interest. New equipment designs are frequently featured. In addition to original data and ideas, the Journal of Paleolimnology also publishes review articles, commentaries and program announcements. A relevant Book Review Section is also featured.