共查询到19条相似文献，搜索用时 781 毫秒
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生物土壤结皮是由土壤微生物和藻类、地衣、苔藓等孢子植物与表层土壤颗粒胶结形成的有机复合体，在退化或受损生态系统中占据重要地位。生物土壤结皮不仅能够改善土壤结构，增强土壤稳定性，还能提高土壤养分含量和酶活性。过去有关生物结皮的研究主要集中在其对荒漠地区及干旱半干旱地区的功能和作用上，作为陆地生态系统中重要的地表覆被物，生物结皮还能够通过光合作用影响土壤有机碳、一氧化碳含量及其稳定性，近年来关于生物土壤结皮如何影响全球碳循环和碳平衡逐渐成为研究者的主流方向。该研究综述了生物结皮覆盖下土壤理化性质、土壤碳循环和土壤呼吸等方面的变化，总结了生物土壤结皮影响生态系统碳循环过程的研究工作和取得的成果，并对未来研究重点进行展望，旨在为实现“碳中和”目标提供新的参考。 相似文献
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草地是我国重要的土地利用类型之一,草地生态系统有机碳库是全球碳循环的重要组成部分,其积累和分解的变化直接影响全球的碳平衡,研究草地土壤有机碳库的影响因素,对于准确评估我国草地生态系统的固碳潜力具有重要的科学意义。该研究在对现有资料整理的基础上,着重综述了自然因子、人类活动以及气候变化等因素对草地土壤碳储量影响的国内外研究进展,指出了目前草地土壤有机碳研究存在的问题,探讨草地固碳对外界因子的响应机制和适应对策,提出了草地土壤碳储量影响因素研究的发展趋势,并对今后草地土壤有机碳研究进行了展望。 相似文献
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以黄河流域湿地保护区为研究对象,采用涡度相关法,对黄河流域不同湿地生态系统呼吸通量观测,并测定了不同湿地植被碳储量和土壤碳储量,探讨了不同湿地生态系统碳储量与呼吸的关系,探究湿地碳循作用机理,以期为保护湿地生态系统提供参考依据.结果 表明:在季节尺度上,黄河流域不同湿地植被生长季具有明显的碳汇功能,生态系统呼吸(Rs)随着月份的增加呈倒"V"型变化特征;生态系统碳交换(NEE)和生态系统总初级生产力(GPP)随着月份的增加呈"V"型变化特征,在8月达到最大.不同湿地植被生物量与碳储量的分布基本一致,其中地上生物量高于地下生物量;植被碳储量大致表现为芦苇群落＞苔草群落＞水蓼群落＞荫草群落,其中不同湿地群落植被碳储量差异均显著(P＜0.05).土壤有机碳含量和有机碳储量均呈一致的变化规律,其中以表层土壤最高,随土壤深度的增加逐渐降低,其中20～40 cm以下土壤有机碳含量变化范围相对较小;80～100 cm土壤有机碳含量最低.土壤有机碳储量和植被碳储量与生态系统碳呼吸呈显著或极显著正相关;GPP和PAR与植被碳和有机碳储量没有显著的相关性,PAR与有机碳和有机碳储量呈负相关;从相关系数绝对值来看,与土壤有机碳储量的相关系数高于植被碳储量的相关系数,并且芦苇群落、苔草群落的相关系数绝对值高于水蓼群落、荫草群落.土壤有机碳储量和植被碳储量对NEE的路径系数分别为0.52和0.43,表明土壤有机碳储量和植被碳储量直接影响黄河流域芦苇湿地NEE通量,而Rs对NEE通量起到间接的影响作用;此外,光合有效辐射与NEE呈显著负相关关系,即随着PAR的增强,芦苇湿地生态系统的固碳能力在逐渐增强.由此说明土壤有机碳储量能够更好的指示NEE通量的变化. 相似文献
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以宁夏荒漠草原不同土地利用方式(耕地、弃耕地、草地和柠条地)的土壤为研究对象,测定了不同土层土壤有机碳和活性有机碳含量,分析了土壤活性有机碳占有机碳的比例,以期探寻不同土地利用方式对土壤活性有机碳的影响。结果表明:不同土地利用方式土壤总有机碳含量范围在1.78~6.17 g·kg^-1,具体表现为弃耕地>柠条地>草地>耕地。表层(0~5 cm)土壤有机碳含量显著高于深层(10~60 cm),说明荒漠草原土壤有机碳主要富集在表层;4种土地利用方式土壤易氧化有机碳含量为0.57~1.38 mg·g^-1,变化趋势具体表现为柠条地>草地>耕地>弃耕地,且柠条地在每个土层都高于其它3种土地利用方式;土壤可溶性有机碳含量范围为6.8~11.1 mg·kg^-1,变化趋势表现为草地>耕地>柠条地>弃耕地。土壤易氧化有机碳含量占有机碳的比例范围为13.7%~43.1%,大小排序为柠条地>耕地>草地>弃耕地;土壤可溶性有机碳含量占有机碳的比例范围为0.11%~0.48%,比例大小为耕地>草地>柠条地>弃耕地,耕地和草地中土壤可溶性有机碳含量占有机碳比例随着土壤深度的增加而减小,这与有机碳在耕地和草地中变化趋势一致。土地利用变化可以显著影响土壤活性有机碳的含量与分布,能够敏感的反映土壤碳库的变化,可以作为评价宁夏荒漠草原土壤质量和肥力的指标之一。 相似文献
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为系统梳理生物炭对土壤微生物活动、群落等方面影响的研究进展和未来发展趋势，以2007-2020年Web of Science核心合集数据库中针对生物炭调控土壤微生物的文献为样本，采用文献计量学软件CiteSpace对文献的年发文量、研究力量和研究热点进行了可视化分析。从论文数量和质量来看，近年来以生物炭为主题对土壤微生物研究的发文数量呈现急剧增长趋势，发文数量最多的国家是中国和美国。文献排名TOP 10的科研机构有中国科学院、浙江大学和康奈尔大学等，作者分析显示科研团队之间存在深入的学术交流。基于关键词聚类分析和突现词分析，研究主题热点集中在不同材质、温度等条件制备的生物炭对土壤微生物群落结构、细菌和古菌的影响。该领域未来应更加注重生物炭改变土壤微生物的内在机理研究，提高生物炭和土壤微生物的联合作用关注度。 相似文献
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阐述并总结了森林碳储量估算的主要方法，即生物量法、蓄积量法、涡度相关法、遥感模型模拟法等，根据研究选择适用于城市绿地碳储量估算的方法进行分析。同时，指出城市绿地碳储量估算的不足，并展望城市绿地碳储量研究发展趋势，加强对城市绿地的监测和管理，采取有效的措施保护城市绿地，提高其碳储量，为缓解气候变化贡献力量。 相似文献
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以巨菌草为试材，采用方差分析法，将样地人工种植巨菌草按照种植时长分为1年(FY)和2年(SY),设置根际、株缘和株间为水平方向，0～100 cm为垂直方向，并设置裸沙地作为对照(CK),研究了人工种植巨菌草后土壤养分分布特征，以期为该地区土壤改良研究提供参考依据。结果表明：土壤有机碳，速效氮、速效磷含量随着种植时间的增加呈正相关关系，速效钾含量呈先上升后下降趋势，其中表层土壤的增加效应最大，随着土壤深度增加，增加效应逐渐减弱。最底层土壤效果最小，其中速效磷对巨菌草种植时间的影响最明显且SY土壤养分的增加效果最为明显。垂直方向对速效氮、速效磷和速效钾的效果集中于表层以下，有机碳多集中于10 cm土层以下，且随着土层深度的加深，该效应逐渐减弱；对于水平方向，根际对于相同深度的增幅效果最高，随着土层深度的加深，该作用逐渐减弱。 相似文献
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为探究坡位对油松林土壤理化性质的影响，以冀西北不同坡位油松林为研究对象，分析不同坡位土壤理化性质差异。结果表明：(1)冀西北油松林土壤容重在1.01～1.09 g/cm3之间变动，土壤容重坡上普遍高于坡下，二者差异显著；垂直梯度土壤容重随土层深度增加而增加。(2)土壤总孔隙度变化范围为43.48%～61.48%,随土层厚度增加而减少，坡上与坡下差异显著，平均来看坡下高于坡上。(3)土壤持水能力坡上与坡下差异较大，坡下总体高于坡上，其土壤饱和持水量最大相差108 t/hm2。(4)土壤养分坡上和坡下总体差异显著，均呈现坡下>坡上；从土壤垂直梯度来看，全氮、全磷与有效磷随土层厚度增加而增加，全钾、碱解氮与速效钾在土层垂直梯度上变化不明显。有机碳随土层厚度增加而减小，土壤pH值坡上与坡下差异不明显 相似文献
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Forest gradient response in Sierran landscapes: the physical template 总被引：13，自引：0，他引：13
Urban Dean L. Miller Carol Halpin Patrick N. Stephenson Nathan L. 《Landscape Ecology》2000,15(7):603-620
Vegetation pattern on landscapes is the manifestation of physical gradients, biotic response to these gradients, and disturbances. Here we focus on the physical template as it governs the distribution of mixed-conifer forests in California's Sierra Nevada. We extended a forest simulation model to examine montane environmental gradients, emphasizing factors affecting the water balance in these summer-dry landscapes. The model simulates the soil moisture regime in terms of the interaction of water supply and demand: supply depends on precipitation and water storage, while evapotranspirational demand varies with solar radiation and temperature. The forest cover itself can affect the water balance via canopy interception and evapotranspiration. We simulated Sierran forests as slope facets, defined as gridded stands of homogeneous topographic exposure, and verified simulated gradient response against sample quadrats distributed across Sequoia National Park. We then performed a modified sensitivity analysis of abiotic factors governing the physical gradient. Importantly, the model's sensitivity to temperature, precipitation, and soil depth varies considerably over the physical template, particularly relative to elevation. The physical drivers of the water balance have characteristic spatial scales that differ by orders of magnitude. Across large spatial extents, temperature and precipitation as defined by elevation primarily govern the location of the mixed conifer zone. If the analysis is constrained to elevations within the mixed-conifer zone, local topography comes into play as it influences drainage. Soil depth varies considerably at all measured scales, and is especially dominant at fine (within-stand) scales. Physical site variables can influence soil moisture deficit either by affecting water supply or water demand; these effects have qualitatively different implications for forest response. These results have clear implications about purely inferential approaches to gradient analysis, and bear strongly on our ability to use correlative approaches in assessing the potential responses of montane forests to anthropogenic climatic change. 相似文献
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Nature-based solutions (NBSs) enhance the potential for mitigation and adaptation to climate change in cities. Among the environmental benefits offered by these measures, enhanced biodiversity, increased carbon storage, reduction of extreme temperatures, and pluvial flood control are crucial. The purpose of this study was to establish an integrated methodology for quantifying the benefits of NBSs and complementary measures and to apply it in a neighbourhood of Donostia-San Sebastián (Spain), where two alternative designs that incorporated NBSs and complementary measures were designed. Then, the individual effectiveness of the four variables was measured using both in-situ measurements and modelling approaches. For the integrated effectiveness, a multi-criteria decision analysis was employed. Both the ‘feasible’ design and the ‘ideal’ one led to an increase in biodiversity (46 and 108 %, respectively) and carbon storage (50 and 130 %, respectively). When considering each measure independently, putting soil provided the highest benefits for carbon capture and biodiversity; meanwhile, planting woody species and installing light-coloured permeable pavements and water fountains reduced the mean radiant temperature by 26.5 K and the air temperature by 0.5 and 2.5 K, respectively, in specific places. Finally, the importance of quantifying the multiple environmental benefits of NBSs for the selection of climate-smart options in urban planning has been highlighted. 相似文献
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Mikaela Schmitt-Harsh Sarah K. Mincey Matt Patterson Burnell C. Fischer Tom P. Evans 《Urban Forestry & Urban Greening》2013,12(4):454-463
In conjunction with urbanization and its importance as a major driver of land-use change, increased efforts have been placed on understanding urban forests and the provisioning of ecosystem services. However, very little research has been conducted on private property and little is known about the structure and function of privately owned urban forests. This research examines the structure of and carbon storage services provided by private residential urban forests in a moderate-sized Midwestern city. The primary research questions are as follows: What is the structure of private urban forests, and how does it vary across parcels? How much carbon is stored in tree and soil pools of private urban forests, and how does carbon vary across parcels? Ecological inventories were conducted on 100 residential parcels within 14 Neighborhood and Homeowners Associations of varying size and development age. Tree species richness, diversity, density, and diameter distribution were determined on a per parcel basis and for the entire tree population sampled. Further, tree and soil carbon storage were determined for each parcel. Results of this research demonstrated large variability in per-parcel tree metrics. Twelve of the parcels sampled had two or fewer trees, while eleven had greater than 50 trees. Further, tree carbon storage ranged from no carbon to 11.22 kg C m?2. Alternatively, soil carbon storage was less variable and averaged 4.7 kg C m?2, approximately 1.9 times higher than the average carbon stored in trees (2.5 kg C m?2). Management efforts aimed at maintaining or enhancing carbon storage and other ecosystem services should focus on both soil protection and maximizing services in living biomass. Our results demonstrate that sustaining tree-produced ecosystem services requires maintenance of large old trees and species diversity, not only in terms of relative abundance, but also relative dominance, and in combination, species–specific size distributions. 相似文献
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运用Arc View 3.2和CITYgreen 5.0模型对昆明市官渡古镇内法定寺周边休闲绿地进行生态效益的量化分析,并利用该软件的生长模拟功能对10a后的生态效益进行了预测。结果表明:该休闲绿地与周围建筑及附属设施布局合理,绿地植物整体生长良好,较好地发挥了对环境的改善作用。该绿地碳储存量为25.25t,2010年碳吸收总量0.52t,植被释放氧气1.39t,清除大气污染物32.93kg。模拟得出2020年其碳储存量累积达到55.09t,碳吸收量1.24t,释放氧气3.31t,清除大气污染物71.82kg。 相似文献
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The area of land occupied by exurban residential development is significant and has been increasing over the past several decades in the United States. Considerable attention has been drawn to the measurement of regional-scale patterns of land-cover change and assessment of its environmental and socioeconomic consequences. Yet little is known about the quantity of land-cover change within individual exurban residential parcels, which reflect homeowner preferences, land-management strategies, and the ecosystem services they generate. Similarly, little is known about the spatial autocorrelation of land cover among parcels and how it may change over time. Using a dataset delineating land-cover change within exurban residential parcels in southeastern Michigan from 1960 to 2000, the quantity and composition of land cover and carbon storage are examined. The spatial similarity of land-cover quantity among neighboring parcels is evaluated using local indicators of spatial association. Results show, among other findings, that (1) the number of exurban residential parcels, the quantity of tree cover, and amount of carbon storage increased steadily from 1960 to 2000; (2) the distribution of parcel sizes remained relatively constant and dominated by small parcels; (3) an increasing proportion of parcels were significantly similar to their neighbors; and (4) using a benefits transfer approach, new exurban parcels are estimated to store ~15,000–29,000 kg C over the study period. The measured changes in land cover and carbon storage improve our understanding of how ecosystem services may change in human-dominated landscapes and provide evidence that policy opportunities are available to increase carbon management. 相似文献
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为了解冀北坝上坝下地区华北落叶松林土壤碳汇功能的差异,对河北省北部坝上坝下地区的华北落叶松林的土壤有机碳含量及碳密度进行了对比研究。结果表明,坝下地区华北落叶松人工林各土层土壤有机碳含量高于坝上地区,但其差异随土层深度的变化而有所不同;坝上及坝下地区18年生华北落叶松林土壤有机碳密度未表现出明显差异,分别为15.6 kg/m2和13.2 kg/m2;40年生华北落叶松林土壤有机碳密度则有显著差异,分别为21.9 kg/m2和27.9 kg/m2;坝上及坝下地区华北落叶松人工林土壤有机碳含量的垂直分布表现出不同的变化趋势,坝上地区土壤有机碳含量随土壤深度增加而下降的趋势较缓,而坝下地区下降趋势更为明显。 相似文献