Suzanne McGowan, Jack H. Lacey, Stefan Engels, John Boyle, Charlotte Briddon, Melanie J. Leng, Heather L. Moorhouse, Virginia Panizzo, Muhammad Shafiq
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We analysed sediment cores from seven sites across a flood-pulse multi-basin wetland, Tasik Chini in Peninsular Malaysia (for percentage LOI<sub>550</sub>, sediment density and spheroidal carbonaceous particles), and conducted more analyses on three <sup>210</sup>Pb-dated cores (X-ray fluorescence of elements, grain size analysis, carbon isotopes, C/N ratios, carotenoid pigments) to gain an understanding of the drivers of organic carbon accumulation rates (OCARs) since 1860 \n<span>ce.</span> The median OCAR of 85 g m<sup>−2</sup> a<sup>−1</sup> for the basin since 1945 \n<span>ce</span> was higher than in other floodplain and temperate lakes and in line with other tropical forest lakes. However, we found evidence for different mechanisms of OC deposition across the basin. In ‘autochthonous mode’, the site with minimal local land disturbance had lowest OCARs and OC was derived mainly from autochthonous production, which rose slightly around 1940 \n<span>ce</span> when regional land disturbance increased nutrient influx to the basin. The site with the most long-term and intensive land disturbance through forest removal (1940s) and then conversion to rubber and oil palm farming (1980s) functioned mainly in ‘allochthonous mode’; that is, increases in OCARs after 1940 \n<span>ce</span> were driven by deposition of soil-derived OC. The highest OCARs were in the basin that was converted to oil palm after the 1980s and had increased iron mining activity in the 2000s; because this site was located distal from the flood pulse and became increasingly hydrologically disconnected after a low rainfall period in the 1970s, the lake responded strongly in ‘autochthonous mode’, through encroachment of fringing swamp, the spread of benthic algae and macrophytes, and efficient sediment retention. Weir installation in 1995 \n<span>ce</span> raised water levels and increased lentic conditions, promoting autochthonous OC production and sedimentation across all basins. The long-term fate of this more recently deposited OC remains uncertain because it is more labile. Overall Tasik Chini has responded strongly to land use changes since at least the 1940s, earlier than anticipated in this region of Southeast Asia, and the sedimentary proxies indicate large changes in the ecosystem function and capacity for C storage over the past ca. 80 years. Most of these shifts have increased OC accumulation by strengthening autochthonous production or allochthonous OC fluxes, but the implications for other aspects of the C cycle, including catchment soil C loss and greenhouse gas production, need to be accounted for when evaluating the overall impacts of land and hydrological disruption.</p>","PeriodicalId":16929,"journal":{"name":"Journal of Quaternary Science","volume":"40 4","pages":"657-670"},"PeriodicalIF":1.9000,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jqs.3672","citationCount":"0","resultStr":"{\"title\":\"Land use, hydroclimate and damming influence organic carbon sedimentation in a flood pulse wetland, Malaysia\",\"authors\":\"Suzanne McGowan, Jack H. Lacey, Stefan Engels, John Boyle, Charlotte Briddon, Melanie J. Leng, Heather L. 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We analysed sediment cores from seven sites across a flood-pulse multi-basin wetland, Tasik Chini in Peninsular Malaysia (for percentage LOI<sub>550</sub>, sediment density and spheroidal carbonaceous particles), and conducted more analyses on three <sup>210</sup>Pb-dated cores (X-ray fluorescence of elements, grain size analysis, carbon isotopes, C/N ratios, carotenoid pigments) to gain an understanding of the drivers of organic carbon accumulation rates (OCARs) since 1860 \\n<span>ce.</span> The median OCAR of 85 g m<sup>−2</sup> a<sup>−1</sup> for the basin since 1945 \\n<span>ce</span> was higher than in other floodplain and temperate lakes and in line with other tropical forest lakes. However, we found evidence for different mechanisms of OC deposition across the basin. In ‘autochthonous mode’, the site with minimal local land disturbance had lowest OCARs and OC was derived mainly from autochthonous production, which rose slightly around 1940 \\n<span>ce</span> when regional land disturbance increased nutrient influx to the basin. The site with the most long-term and intensive land disturbance through forest removal (1940s) and then conversion to rubber and oil palm farming (1980s) functioned mainly in ‘allochthonous mode’; that is, increases in OCARs after 1940 \\n<span>ce</span> were driven by deposition of soil-derived OC. The highest OCARs were in the basin that was converted to oil palm after the 1980s and had increased iron mining activity in the 2000s; because this site was located distal from the flood pulse and became increasingly hydrologically disconnected after a low rainfall period in the 1970s, the lake responded strongly in ‘autochthonous mode’, through encroachment of fringing swamp, the spread of benthic algae and macrophytes, and efficient sediment retention. Weir installation in 1995 \\n<span>ce</span> raised water levels and increased lentic conditions, promoting autochthonous OC production and sedimentation across all basins. The long-term fate of this more recently deposited OC remains uncertain because it is more labile. 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引用次数: 0
摘要
位于洪泛区和热带森林的水体被认为是重要的碳储存库,但许多水体受到来自筑坝、土地利用和气候变化的巨大压力。沉积记录保存了长期档案,有助于了解这些变化如何影响碳储量的数量和质量。我们分析了马来西亚半岛Tasik Chini洪水脉冲多流域湿地的7个地点的沉积物岩心(LOI550百分比,沉积物密度和球形碳质颗粒),并对三个210pb年代的岩心进行了更多分析(元素的x射线荧光,粒度分析,碳同位素,C/N比率,类胡萝卜素色素),以了解自1860年以来有机碳积累速率(OCARs)的驱动因素。流域自1945年以来的OCAR中值为85 g m−2 a−1,高于其他河漫滩和温带湖泊,与其他热带森林湖泊基本一致。然而,我们在整个盆地中发现了不同OC沉积机制的证据。在“原生模式”下,局地扰动最小的样地OCARs最低,OC主要来源于局地生产,在1940年前后,局地扰动增加了向盆地的养分流入,OCARs略有上升。由于森林砍伐(20世纪40年代)和随后转变为橡胶和油棕种植(20世纪80年代)而遭受最长期和最严重土地干扰的场地主要以“异域模式”运作;也就是说,1940年以后OCARs的增加是由土壤来源的OC沉积驱动的。ocar最高的是在20世纪80年代后转为油棕的盆地,并且在21世纪初增加了铁开采活动;由于该地点位于远离洪水脉冲的地方,并且在20世纪70年代的低降雨期之后,水文上变得越来越脱节,因此湖泊通过边缘沼泽的侵蚀、底栖藻类和大型植物的传播以及有效的沉积物保留,以“原生模式”做出强烈反应。1995年安装的堰提高了水位,增加了生态条件,促进了所有盆地的原生OC生产和沉积。这种最近沉积的有机碳的长期命运仍然不确定,因为它更不稳定。总体而言,至少从20世纪40年代开始,中国大陆就对土地利用变化做出了强烈的响应,比东南亚地区的预期要早。沉积代用物表明,在过去约80年里,生态系统功能和碳储存能力发生了巨大变化。大多数这些变化通过加强本地生产或外来OC通量而增加了OC积累,但在评估土地和水文破坏的总体影响时,需要考虑对C循环其他方面的影响,包括流域土壤C损失和温室气体产生。
Land use, hydroclimate and damming influence organic carbon sedimentation in a flood pulse wetland, Malaysia
Water bodies located in floodplains and tropical forests are known to be important carbon stores, but many are subjected to intensive pressures from damming, land use and climate changes. Sedimentary records preserve long-term archives for understanding how such changes affect the quantity and quality of carbon stores. We analysed sediment cores from seven sites across a flood-pulse multi-basin wetland, Tasik Chini in Peninsular Malaysia (for percentage LOI550, sediment density and spheroidal carbonaceous particles), and conducted more analyses on three 210Pb-dated cores (X-ray fluorescence of elements, grain size analysis, carbon isotopes, C/N ratios, carotenoid pigments) to gain an understanding of the drivers of organic carbon accumulation rates (OCARs) since 1860
ce. The median OCAR of 85 g m−2 a−1 for the basin since 1945
ce was higher than in other floodplain and temperate lakes and in line with other tropical forest lakes. However, we found evidence for different mechanisms of OC deposition across the basin. In ‘autochthonous mode’, the site with minimal local land disturbance had lowest OCARs and OC was derived mainly from autochthonous production, which rose slightly around 1940
ce when regional land disturbance increased nutrient influx to the basin. The site with the most long-term and intensive land disturbance through forest removal (1940s) and then conversion to rubber and oil palm farming (1980s) functioned mainly in ‘allochthonous mode’; that is, increases in OCARs after 1940
ce were driven by deposition of soil-derived OC. The highest OCARs were in the basin that was converted to oil palm after the 1980s and had increased iron mining activity in the 2000s; because this site was located distal from the flood pulse and became increasingly hydrologically disconnected after a low rainfall period in the 1970s, the lake responded strongly in ‘autochthonous mode’, through encroachment of fringing swamp, the spread of benthic algae and macrophytes, and efficient sediment retention. Weir installation in 1995
ce raised water levels and increased lentic conditions, promoting autochthonous OC production and sedimentation across all basins. The long-term fate of this more recently deposited OC remains uncertain because it is more labile. Overall Tasik Chini has responded strongly to land use changes since at least the 1940s, earlier than anticipated in this region of Southeast Asia, and the sedimentary proxies indicate large changes in the ecosystem function and capacity for C storage over the past ca. 80 years. Most of these shifts have increased OC accumulation by strengthening autochthonous production or allochthonous OC fluxes, but the implications for other aspects of the C cycle, including catchment soil C loss and greenhouse gas production, need to be accounted for when evaluating the overall impacts of land and hydrological disruption.
期刊介绍:
The Journal of Quaternary Science publishes original papers on any field of Quaternary research, and aims to promote a wider appreciation and deeper understanding of the earth''s history during the last 2.58 million years. Papers from a wide range of disciplines appear in JQS including, for example, Archaeology, Botany, Climatology, Geochemistry, Geochronology, Geology, Geomorphology, Geophysics, Glaciology, Limnology, Oceanography, Palaeoceanography, Palaeoclimatology, Palaeoecology, Palaeontology, Soil Science and Zoology. The journal particularly welcomes papers reporting the results of interdisciplinary or multidisciplinary research which are of wide international interest to Quaternary scientists. Short communications and correspondence relating to views and information contained in JQS may also be considered for publication.