Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and prese...Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and preserving paleoenvironmental records.Despite their importance,peatlands outside protected areas face degradation by grazing and fires,threatening their ability to regulate ecosystem processes sensitive to temperature,such as greenhouse gas emissions,water cycling,biological activity,and organic matter decomposition.Since 2016,we have monitored peat temperatures in two contrasting peatlands–one preserved(within a protected area)and one disturbed(outside the protected area)–to understand how anthropogenic disturbances and climate variability impact these fragile ecosystems.Seasonal patterns dominated temperature variation,accounting for 60% of air and 81%–92% of peatland temperature variation.However,average temperatures and amplitudes differed between peatlands and depths.Interannual variability revealed stronger trends in the disturbed peatland,where a 1℃ increase in air temperature caused the trend to increase 0.70℃–0.87℃ on average at depths of 0.85 m–0.92 m.By contrast,the preserved peatland showed smaller increases(0.20℃–0.24℃)at comparable depths(1.06 m–1.24 m),suggesting a greater resilience.Temperature variation in the monitored peatlands was majorly driven by seasonal patterns,as revealed by time series decomposition and sinewave fit.Average temperature and amplitude varied between the two peatlands and among sampling sites,reflecting differences in environmental conditions and measurement depth.Interannual variability also exhibited distinct effects between peatlands and monitoring sites.The time series trend component showed more pronounced fluctuations at shallower depths and in the disturbed peatland.For every 1℃ increase in the trend component of the air temperature,the trend component of the peatland time series increased by 0.70℃ and 0.87℃on average at depths of 0.85 m and 0.92 m,respectively,in the disturbed peatland.In contrast,the preserved peatland exhibited smaller increases of 0.20℃ and 0.24℃ at comparable depths(1.06 m and 1.24 m).These findings highlight the potential for feedback responses between peatland disturbance and climate change,threatening their critical role in regulating carbon and water cycles.Expanding long-term monitoring,strengthening conservation efforts,and raising public awareness are essential to safeguard the ecosystem services provided by tropical mountain peatlands.展开更多
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia...Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.展开更多
黄河流域古河道的变迁对文化遗址形成的影响,是黄河文化研究的重要科学问题之一。内蒙古巴彦淖尔国家地质公园位于黄河中上游的河套盆地,公园内汉代临戎古城遗址的位置一直存在争论,确定黄河古河道与其相对位置关系是关键。通过对临戎...黄河流域古河道的变迁对文化遗址形成的影响,是黄河文化研究的重要科学问题之一。内蒙古巴彦淖尔国家地质公园位于黄河中上游的河套盆地,公园内汉代临戎古城遗址的位置一直存在争论,确定黄河古河道与其相对位置关系是关键。通过对临戎古城遗址周边10 km范围进行网格化槽型钻取心,利用钻孔数据构建三维粒度属性模型与沉积结构模型,对隐伏的古河道位置进行了较为精准地确定;并通过钻孔岩心沉积相分析与年代学测试,对古河道的沉积结构与年代进行了验证。结果表明,临戎古城遗址西3 km处存在(2.39±0.24) ka~(1.36±0.05) Cal ka BP的黄河古河道,自南向北流经临戎城西。以此确定的黄河与朔方郡各属县治城的相对位置符合史料的记载。本研究从沉积学角度为巴彦淖尔国家地质公园临戎古城遗址位置的考证提供了地质科学依据。展开更多
基金This study was financed in part by the Coordenacao de Aperfeiçoamento de Pessoal de Nivel Superior-Brasil(CAPES)-Finance Code 001the Brazilian Conselho Nacional de Pesquisa-CNPq(study and research grants and research funding-Process 303666/2018-8,408162/2018-0,441335/2020-9,302969/2021-7,and 50484/2022-4)Fundacao de ApoioaPesquisa do Estado de Minas Gerais-FAPEMIG(study grants and research funding-Process CRA/APQ 0100-18,APQ-03364-21 and CAG/PPM 00568-16).
文摘Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and preserving paleoenvironmental records.Despite their importance,peatlands outside protected areas face degradation by grazing and fires,threatening their ability to regulate ecosystem processes sensitive to temperature,such as greenhouse gas emissions,water cycling,biological activity,and organic matter decomposition.Since 2016,we have monitored peat temperatures in two contrasting peatlands–one preserved(within a protected area)and one disturbed(outside the protected area)–to understand how anthropogenic disturbances and climate variability impact these fragile ecosystems.Seasonal patterns dominated temperature variation,accounting for 60% of air and 81%–92% of peatland temperature variation.However,average temperatures and amplitudes differed between peatlands and depths.Interannual variability revealed stronger trends in the disturbed peatland,where a 1℃ increase in air temperature caused the trend to increase 0.70℃–0.87℃ on average at depths of 0.85 m–0.92 m.By contrast,the preserved peatland showed smaller increases(0.20℃–0.24℃)at comparable depths(1.06 m–1.24 m),suggesting a greater resilience.Temperature variation in the monitored peatlands was majorly driven by seasonal patterns,as revealed by time series decomposition and sinewave fit.Average temperature and amplitude varied between the two peatlands and among sampling sites,reflecting differences in environmental conditions and measurement depth.Interannual variability also exhibited distinct effects between peatlands and monitoring sites.The time series trend component showed more pronounced fluctuations at shallower depths and in the disturbed peatland.For every 1℃ increase in the trend component of the air temperature,the trend component of the peatland time series increased by 0.70℃ and 0.87℃on average at depths of 0.85 m and 0.92 m,respectively,in the disturbed peatland.In contrast,the preserved peatland exhibited smaller increases of 0.20℃ and 0.24℃ at comparable depths(1.06 m and 1.24 m).These findings highlight the potential for feedback responses between peatland disturbance and climate change,threatening their critical role in regulating carbon and water cycles.Expanding long-term monitoring,strengthening conservation efforts,and raising public awareness are essential to safeguard the ecosystem services provided by tropical mountain peatlands.
文摘Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.
文摘黄河流域古河道的变迁对文化遗址形成的影响,是黄河文化研究的重要科学问题之一。内蒙古巴彦淖尔国家地质公园位于黄河中上游的河套盆地,公园内汉代临戎古城遗址的位置一直存在争论,确定黄河古河道与其相对位置关系是关键。通过对临戎古城遗址周边10 km范围进行网格化槽型钻取心,利用钻孔数据构建三维粒度属性模型与沉积结构模型,对隐伏的古河道位置进行了较为精准地确定;并通过钻孔岩心沉积相分析与年代学测试,对古河道的沉积结构与年代进行了验证。结果表明,临戎古城遗址西3 km处存在(2.39±0.24) ka~(1.36±0.05) Cal ka BP的黄河古河道,自南向北流经临戎城西。以此确定的黄河与朔方郡各属县治城的相对位置符合史料的记载。本研究从沉积学角度为巴彦淖尔国家地质公园临戎古城遗址位置的考证提供了地质科学依据。
