相关实验视频
Updated: Jan 10, 2026

08:20
In Situ Soil Moisture Sensors in Undisturbed Soils
Published on: November 18, 2022
7.3K
全球土壤湿度动态:贡献的分配及其与GPP的关联
Yang Li1,2, Leer Bao1, Panxing He3
1College of Agriculture, Yanbian University, Yanji, Jilin, China.
Frontiers in plant science
|November 20, 2025
概括
全球土壤湿度 (SM) 正在下降,更深层的土壤层显著影响了变化. 土壤湿度与总初级生产率 (GPP) 有积极的相关性,特别是在草原和耕地根部区域.
科学领域:
- 地球系统科学 地球系统科学
- 水文学的水文学
- 生态生态学 生态生态学
背景情况:
- 土壤湿度 (SM) 对于陆地与大气的相互作用至关重要,但其动态结构特征尚未得到充分理解.
- 整个生态系统的土壤水分和总初级生产率 (GPP) 之间的关系需要进一步研究.
研究的目的:
- 开发一个框架来量化土壤湿度对土壤总湿度变量 (TSMV) 的贡献.
- 分析全球TSMV的结构特征,包括趋势和跨年变化.
- 探索土壤水分和GPP之间的全球相关性.
主要方法:
- 利用了GLDAS-Noah SM数据 (1948-2024) 和一个"三维分解+共变性归因"框架.
- 将TSMV分解为长期趋势和年度间变化 (IAV).
- 集成的MODIS MCD12C1和GOSIF GPP数据集 (2000-2024) 以评估SM-GPP的相关性.
主要成果:
- 全球总土壤湿度 (TSM) 从2000年到2024年呈现下降趋势,在所有季节都有下降.
- 40-200厘米的土壤层对TSMV的IAV有很大的贡献,显示出显著的空间变化.
- 在SM和GPP之间发现了积极的总体相关性,特别明显在草原和耕地的10-100厘米根区.
结论:
- 开发的框架有效量化了SM对TSMV的贡献,为全球分析提供了方法论基础.
- 较深的土壤层在土壤湿度变化中起着关键作用.
- 土壤湿度是主要陆地生态系统中GPP的关键驱动因素,突出了它对碳循环的重要性.
相关概念视频
Precipitation Gravimetry
13.2K
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
13.2K
Precipitation Processes
4.7K
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
4.7K
Precipitation and Co-precipitation
4.0K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
4.0K
Regulation of Transpiration by Stomata
30.8K
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
30.8K
Global Climate Change
28.7K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
28.7K
Moisture Content and Bulking of Aggregate
408
The moisture content of aggregates is a crucial factor in construction, particularly in concrete mixing, as it influences the total water required in the mix. Moisture content represents the water coated on the exterior surface of the aggregate existing in a saturated and surface-dry condition. The total water content of a moist aggregate is the sum of its moisture content and water absorption.
When aggregates are exposed to rain or sit in stockpiles, they absorb moisture, which must be...
When aggregates are exposed to rain or sit in stockpiles, they absorb moisture, which must be...
408

