荒漠草原是陆地生态系统中最为脆弱且受人类干扰较为严重的生态类型之一,精准模拟其碳水通量及对人为干扰的响应,不仅能够揭示其复杂的生态学过程,而且还可为人为生态修复和保护提供决策依据。生态模型能够有效地模拟陆地生态系统的碳...荒漠草原是陆地生态系统中最为脆弱且受人类干扰较为严重的生态类型之一,精准模拟其碳水通量及对人为干扰的响应,不仅能够揭示其复杂的生态学过程,而且还可为人为生态修复和保护提供决策依据。生态模型能够有效地模拟陆地生态系统的碳水循环过程,但模型众多的参数及其取值的合理性限制了其普遍应用,故探索参数优化是提升生态模型应用的有效途径。利用PEST参数优化方法和涡度相关观测数据对Biome-BGC模型的生理生态参数进行优化,在评估参数优化效果的基础上模拟了1986—2018年宁夏盐池荒漠草原区人工灌丛生态系统的总初级生产力(Gross primary productivity,GPP)和蒸散(Evapotranspiration,ET)。结果表明:(1)参数优化可以改善Biome-BGC模型对荒漠草原区人工灌丛生态系统GPP和ET的模拟效果,参数优化后模拟的GPP和ET均更接近于观测值,其中月尺度的模拟效果更佳;(2)基于PEST的Biome-BGC模型参数优化方法具有较强的普适性,优化后的参数可推广应用于荒漠草原区人工灌丛生态系统长时间序列的GPP和ET模拟;(3)宁夏盐池荒漠草原区人工灌丛生态系统的GPP在1986—2018年呈缓慢上升趋势,增幅为1.47 g C m^(-2)a^(-1),但ET的年际变化率较大,且无显著变化趋势。展开更多
以湖南省邵阳县轻度、中度（弃耕地）和重度石漠化的灌丛生态系统为研究对象,采集3种不同石漠化程度的灌丛植物样品以及0～15、15～30、30～45 cm 3个土层土壤,研究土壤、植被养分的分配格局及相互关系.结果表明：土壤有机碳、全N含量...以湖南省邵阳县轻度、中度（弃耕地）和重度石漠化的灌丛生态系统为研究对象,采集3种不同石漠化程度的灌丛植物样品以及0～15、15～30、30～45 cm 3个土层土壤,研究土壤、植被养分的分配格局及相互关系.结果表明：土壤有机碳、全N含量在不同土层中差异显著,且其含量均随土层深度增加而减少,而全P、全K、全Ca、全Mg含量在各土层间无显著差异;3种石漠化程度灌丛土壤全N、全P、全Ca、全Mg含量差异显著,且中度石漠化样地土壤有机碳、全N和全P含量相对较高.轻度和重度石漠化土壤各元素含量排序均为有机碳〉全K〉全Ca〉全Mg〉全N〉全P,而中度石漠化样地土壤各元素含量排序为有机碳〉全K〉全Ca〉全N〉全Mg〉全P;3种石漠化程度植物各养分含量由高到低依次为Ca〉N〉K〉Mg〉P,且植物N、P含量和土壤全N、全P含量均呈显著正相关.土壤养分状况与植物生长密切相关,根据不同石漠化程度土壤养分状况,应该采用封山育林与人工造林相结合以及针对性施肥的方法来治理石漠化.展开更多
Three-North Shelterbelt Forest （TSF） program, is one of six key forestry programs and has a 73-year construction period, from 1978 to 2050. Quantitative analysis of the carbon sequestration of shrubs in this region ...Three-North Shelterbelt Forest （TSF） program, is one of six key forestry programs and has a 73-year construction period, from 1978 to 2050. Quantitative analysis of the carbon sequestration of shrubs in this region is important for understanding the overall function of carbon sequestration of the forest and other terrestrial ecosystems in China. This study investigated the distribution area of shrubland in the TSF region based on remote sensing images in 1978 and 2008, and calculated the carbon density of shrubland in combination with the field investigation and previous data from published papers. The carbon sequestration quantity and rate from 1978 to 2008 was analyzed for four sub-regions and different types of shrubs in the TSF region. The results revealed that： 1） The area of shrubland in the study area and its four sub-regions increased during the past thirty years. The area of shrubland for the whole region in 2008 was 1.2 × 10^7 ha, 72.8% larger than that in 1978. The Inner Mongolia-Xinjiang Sub-region was the largest shrubland distribution area, while the highest coverage rate was found in the North China Sub-region. 2） In decreasing order of their carbon sequestration, the four types of shrubs considered in this study were Hippophae rhamnoides, Caragana spp., Haloxylon ammodendron and Vitex negundo vat. heterophylla. The carbon sequestration of/-/, rhamnoides, with a maximum mean carbon density of 16.5 Mg C/ha, was significantly higher than that of the other three species. 3） The total carbon sequestration of shrubland in the study region was 4.5 x 107 Mg C with a mean annual carbon sequestration of 1.5× 10^6 Mg C. The carbon density in the four sub-regions decreased in the following order： the Loess Plateau Sub-region, the North China Sub-region, the Northeast China Sub-region and the Inner Mongolia-Xinjiang Sub-region. The paucity of studies and data availability on the large-scale carbon sequestration of shrub species suggests this study provides a baseline reference for future research in this area.展开更多
灌丛在我国山地及干旱半干旱地区广泛分布,是我国陆地生态系统的重要组成部分(Tang et al.,2018),在水源涵养、生物固碳、土壤保持及防风固沙等方面起到了重要的作用(Piao et al.,2009;胡雄蛟等,2021)。近年来,我国开始重视灌丛研究,先...灌丛在我国山地及干旱半干旱地区广泛分布,是我国陆地生态系统的重要组成部分(Tang et al.,2018),在水源涵养、生物固碳、土壤保持及防风固沙等方面起到了重要的作用(Piao et al.,2009;胡雄蛟等,2021)。近年来,我国开始重视灌丛研究,先后开展了中国科学院先导专项课题“中国灌丛生态系统的固碳现状、变化和机制研究”及国家科技基础性工作专项项目“我国主要灌丛植物群落调查”等工作。通过十余年的研究,对我国灌丛植物群落的类型、分布格局、物种组成以及碳收支等有了较系统的认知(谢宗强等,2019)。展开更多
文摘荒漠草原是陆地生态系统中最为脆弱且受人类干扰较为严重的生态类型之一,精准模拟其碳水通量及对人为干扰的响应,不仅能够揭示其复杂的生态学过程,而且还可为人为生态修复和保护提供决策依据。生态模型能够有效地模拟陆地生态系统的碳水循环过程,但模型众多的参数及其取值的合理性限制了其普遍应用,故探索参数优化是提升生态模型应用的有效途径。利用PEST参数优化方法和涡度相关观测数据对Biome-BGC模型的生理生态参数进行优化,在评估参数优化效果的基础上模拟了1986—2018年宁夏盐池荒漠草原区人工灌丛生态系统的总初级生产力(Gross primary productivity,GPP)和蒸散(Evapotranspiration,ET)。结果表明:(1)参数优化可以改善Biome-BGC模型对荒漠草原区人工灌丛生态系统GPP和ET的模拟效果,参数优化后模拟的GPP和ET均更接近于观测值,其中月尺度的模拟效果更佳;(2)基于PEST的Biome-BGC模型参数优化方法具有较强的普适性,优化后的参数可推广应用于荒漠草原区人工灌丛生态系统长时间序列的GPP和ET模拟;(3)宁夏盐池荒漠草原区人工灌丛生态系统的GPP在1986—2018年呈缓慢上升趋势,增幅为1.47 g C m^(-2)a^(-1),但ET的年际变化率较大,且无显著变化趋势。
文摘以湖南省邵阳县轻度、中度（弃耕地）和重度石漠化的灌丛生态系统为研究对象,采集3种不同石漠化程度的灌丛植物样品以及0～15、15～30、30～45 cm 3个土层土壤,研究土壤、植被养分的分配格局及相互关系.结果表明：土壤有机碳、全N含量在不同土层中差异显著,且其含量均随土层深度增加而减少,而全P、全K、全Ca、全Mg含量在各土层间无显著差异;3种石漠化程度灌丛土壤全N、全P、全Ca、全Mg含量差异显著,且中度石漠化样地土壤有机碳、全N和全P含量相对较高.轻度和重度石漠化土壤各元素含量排序均为有机碳〉全K〉全Ca〉全Mg〉全N〉全P,而中度石漠化样地土壤各元素含量排序为有机碳〉全K〉全Ca〉全N〉全Mg〉全P;3种石漠化程度植物各养分含量由高到低依次为Ca〉N〉K〉Mg〉P,且植物N、P含量和土壤全N、全P含量均呈显著正相关.土壤养分状况与植物生长密切相关,根据不同石漠化程度土壤养分状况,应该采用封山育林与人工造林相结合以及针对性施肥的方法来治理石漠化.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060400)
文摘Three-North Shelterbelt Forest （TSF） program, is one of six key forestry programs and has a 73-year construction period, from 1978 to 2050. Quantitative analysis of the carbon sequestration of shrubs in this region is important for understanding the overall function of carbon sequestration of the forest and other terrestrial ecosystems in China. This study investigated the distribution area of shrubland in the TSF region based on remote sensing images in 1978 and 2008, and calculated the carbon density of shrubland in combination with the field investigation and previous data from published papers. The carbon sequestration quantity and rate from 1978 to 2008 was analyzed for four sub-regions and different types of shrubs in the TSF region. The results revealed that： 1） The area of shrubland in the study area and its four sub-regions increased during the past thirty years. The area of shrubland for the whole region in 2008 was 1.2 × 10^7 ha, 72.8% larger than that in 1978. The Inner Mongolia-Xinjiang Sub-region was the largest shrubland distribution area, while the highest coverage rate was found in the North China Sub-region. 2） In decreasing order of their carbon sequestration, the four types of shrubs considered in this study were Hippophae rhamnoides, Caragana spp., Haloxylon ammodendron and Vitex negundo vat. heterophylla. The carbon sequestration of/-/, rhamnoides, with a maximum mean carbon density of 16.5 Mg C/ha, was significantly higher than that of the other three species. 3） The total carbon sequestration of shrubland in the study region was 4.5 x 107 Mg C with a mean annual carbon sequestration of 1.5× 10^6 Mg C. The carbon density in the four sub-regions decreased in the following order： the Loess Plateau Sub-region, the North China Sub-region, the Northeast China Sub-region and the Inner Mongolia-Xinjiang Sub-region. The paucity of studies and data availability on the large-scale carbon sequestration of shrub species suggests this study provides a baseline reference for future research in this area.
文摘灌丛在我国山地及干旱半干旱地区广泛分布,是我国陆地生态系统的重要组成部分(Tang et al.,2018),在水源涵养、生物固碳、土壤保持及防风固沙等方面起到了重要的作用(Piao et al.,2009;胡雄蛟等,2021)。近年来,我国开始重视灌丛研究,先后开展了中国科学院先导专项课题“中国灌丛生态系统的固碳现状、变化和机制研究”及国家科技基础性工作专项项目“我国主要灌丛植物群落调查”等工作。通过十余年的研究,对我国灌丛植物群落的类型、分布格局、物种组成以及碳收支等有了较系统的认知(谢宗强等,2019)。
