scholarly journals Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 105
Author(s):  
Argelia E. Rascón-Ramos ◽  
Martín Martínez-Salvador ◽  
Gabriel Sosa-Pérez ◽  
Federico Villarreal-Guerrero ◽  
Alfredo Pinedo-Alvarez ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Management ◽  
Water Availability ◽  
Dry Forest ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Northern Mexico ◽  
The Difference ◽  
The Impact ◽  
Moisture Dynamics

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

Conflicting drivers of land carbon uptake variability reconciled by land-atmosphere coupling

2020 ◽  
Author(s):  
Vincent Humphrey ◽  
Alexis Berg ◽  
Philippe Ciais ◽  
Christian Frankenberg ◽  
Pierre Gentine ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Vapor Pressure ◽  
Water Availability ◽  
Vapor Pressure Deficit ◽  
Sensitivity Analyses ◽  
Carbon Uptake ◽  
Annual Variability ◽  
Vegetation Activity ◽  
The Impact

&lt;p&gt;Obtaining reliable estimates of the sensitivity of carbon fluxes to water availability, temperature and vapor pressure deficit is essential for constraining climate-carbon feedbacks in Earth system models. However, these variables often co-vary because of soil moisture &amp;#8211; atmosphere feedbacks, especially in situations where they are most susceptible to strongly impact ecosystems (e.g. during droughts and heatwaves), leading to potentially conflicting results when sensitivities are assessed independently. In particular, there is conflicting evidence on the role of temperature versus water availability in explaining these variations at the global scale.&lt;/p&gt;&lt;p&gt;Here, we show that accounting for the effect of soil moisture &amp;#8211; atmosphere coupling resolves much of this controversy. Using idealized climate model experiments, we find that variability in soil moisture accounts for 90% of the inter-annual variability in land carbon uptake, mainly through its impact on photosynthesis. Without SM variability, the inter-annual variability (IAV) of land carbon uptake is almost eliminated. We show that the effects of soil moisture can be decomposed into 1) a direct ecosystem response to soil water stress and 2) a dominant indirect response to extreme temperature and vapor pressure deficit triggered by land-atmosphere coupling and controlled by anomalous soil moisture conditions. &amp;#160;Importantly, these two mechanisms do not necessarily have the same spatial extent, and some regions can be more sensitive to indirect effects than to direct effects.&lt;/p&gt;&lt;p&gt;These two pathways explain why results from coupled climate models suggest a dominant role of soil moisture, while uncoupled simulations diagnose a strong temperature effect. These findings have strong implications for offline model sensitivity analyses as well as field scale manipulation experiments (i.e. rainfall exclusion studies) where the impact of drought on carbon exchange and vegetation activity is often studied by intervening solely on soil moisture content with little consideration of the physical feedbacks on temperature and air humidity occurring in natural conditions.&lt;/p&gt;

scholarly journals Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

2016 ◽  
Author(s):  
C. Fu ◽  
G. Wang ◽  
M. L. Goulden ◽  
R. L. Scott ◽  
K. Bible ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Hydraulic Redistribution ◽  
Energy Budgets ◽  
Soil Moisture Dynamics ◽  
Community Land Model ◽  
The Us ◽  
Hydrological Impact ◽  
The Impact ◽  
Moisture Dynamics

Abstract. Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) has tackled the magnitude of the HR flux itself or the soil moisture dynamics from which HR magnitude can be directly inferred. Here we incorporated Ryel et al.'s (2002) empirical equation describing HR into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture the magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on surface water and energy budgets, and to explore how it may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites characterized by contrasting climate regimes and multiple vegetation types were studied, including the US-Wrc Wind River Crane site in Washington State, the US-SRM Santa Rita Mesquite Savanna site in southern Arizona, and six sites along the Southern California Climate Gradient (US-SCs, g, f, w, c, and d). HR flux, evapotranspiration, and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement match particularly during dry seasons. Our results also reveal that HR has important hydrological impact (on evapotranspiration, Bowen ratio, and soil moisture) in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.

scholarly journals Nutrient Leaching in Extensive Green Roof Substrate Layers With Different Configurations

2021 ◽  
Author(s):  
Chen Xu ◽  
Zaohong Liu ◽  
Guanjun Cai ◽  
Jian Zhan
Keyword(s):  
Green Roofs ◽  
Pollution Source ◽  
Nutrient Leaching ◽  
Rainfall Runoff ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Substrate Layer ◽  
Rainwater Runoff ◽  
The Impact ◽  
Extensive Green Roofs

Abstract Due to substrate layers with different substrate configurations, extensive green roofs (EGRs) exhibit different rainfall runoff retention and pollution interception effects. In the rainfall runoff scouring process, nutrient leaching often occurs in the substrate layer, which becomes a pollution source for rainwater runoff. In this study, six EGR devices with different substrate layer configurations were fabricated. Then, the cumulative leaching quantity (CLQ) and total leaching rate (TLR) of NH4+, TN and TP in the outflow of nine different depth simulated rainfall events under local rainfall characteristics were evaluated and recorded. Furthermore, the impact of different substrate configurations on the pollution interception effects of EGRs for rainfall runoff was studied. Results show that a mixed adsorption substrate in the EGR substrate layer has a more significant rainfall runoff pollution interception capacity than a single adsorption substrate. PVL and PVGL, as EGRs with layered configuration substrate layers, exhibited good NH4+-N interception capacity. The CLQ and TLR of NH4+-N for PVL and PVGL were -114.613 mg and -63.43%, -121.364 mg and -67.16%, respectively. Further, the addition of biochar as a modifier significantly slowed down the substrate layer TP leaching effect and improved the interception effect of NH4+-N and TN. Moreover, although polyacrylamide addition in the substrate layer aggravated the nitrogen leaching phenomenon in the EGRs outflow, but the granular structure substrate layer constructed by it exhibited a significantly inhibited TP leaching effect.

scholarly journals Soil moisture in forage cactus plantations with improvement practices for their resilience

2017 ◽  
Vol 21 (7) ◽  
pp. 481-487 ◽  
Author(s):  
Ailton A. de Carvalho ◽  
Thieres G. F. da Silva ◽  
Luciana S. B. de Souza ◽  
Magna S. B. de Moura ◽  
Gherman G. L. de Araujo ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Water Availability ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Block Design ◽  
Soil Density ◽  
Vertical Variation ◽  
Rainfall Events ◽  
Randomized Block Design

ABSTRACT The present study evaluated soil moisture (θ) in forage cactus plantations under resilience practices such as irrigation, mulching and intercropping with sorghum. The experiment was arranged in a randomized block design with five water availability conditions (0, 8.75, 17.5, 26.25 and 35% of the reference evapotranspiration), and three planting systems: forage cactus exclusive system (PE), forage cactus with mulch (PC) and intercropping between forage cactus and sorghum (PS). Water content was measured until a depth of 0.60 m. Meteorological data were recorded between June 2012 and June 2013. Water content was not affected by different resilience practices and the variation coefficient was low to medium (4.0 to 22.1%). The temporal variation of soil moisture was more affected by the changes in rainfall, while the physical properties (soil density, porosity and grain size) were decisive in the vertical variation. It was concluded that periods with rainfall events favor the alternation of practices to improve forage cactus resilience (irrigation, mulch and intercropping).

scholarly journals The Impact of Drought on Soil Moisture Trends across Brazilian Biomes

2020 ◽  
Author(s):  
Flavio Lopes Ribeiro ◽  
Mario Guevara ◽  
Alma Vázquez-Lule ◽  
Ana Paula Cunha ◽  
Marcelo Zeri ◽  
...  
Keyword(s):  
Soil Moisture ◽  
European Space Agency ◽  
Water Security ◽  
Direct Impact ◽  
The Past ◽  
Space Agency ◽  
The Impact ◽  
Soil Moisture Variability ◽  
Moisture Dynamics ◽  
Agriculture Water

Abstract. Over the past decade, Brazil has experienced severe droughts across its territory, with important implications for soil moisture dynamics. Soil moisture variability has a direct impact on agriculture, water security, and ecosystem services. Nevertheless, there is currently little information on how soil moisture across different biomes respond to drought. In this study, we used satellite soil moisture data from the European Space Agency, from 2009 to 2015, to analyze differences in soil moisture responses to drought for each biome of Brazil: The Amazon, Atlantic Forest, Caatinga, Cerrado, Pampas and Pantanal. We found an overall soil moisture decline of −0.5 %/year (p 

scholarly journals Evaluating the impacts of environmental factors on soil moisture temporal dynamics at different time scales

2020 ◽  
Author(s):  
Qi Chai ◽  
Tiejun Wang ◽  
Chongli Di
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Time Scales ◽  
Temporal Dynamics ◽  
Soil Moisture Dynamics ◽  
Temporal Variance ◽  
The Impact ◽  
Moisture Dynamics ◽  
Different Time Scales

Abstract Soil moisture displays complex spatiotemporal patterns across scales, making it important to disentangle the impacts of environmental factors on soil moisture temporal dynamics at different time scales. This study evaluated the factors affecting soil moisture dynamics at different time scales using long-term soil moisture data obtained from Nebraska and Utah. The empirical mode decomposition method was employed to decompose soil moisture time series into different temporal components with several intrinsic mode functions (IMFs) and one residual component. Results showed that the percent variance contribution (PVC) of IMFs to the total soil moisture temporal variance tended to increase for the IMFs with longer time periods. It indicated that the long-term soil moisture variations in study regions were mainly determined by low-temporal frequency signals related to seasonal climate and vegetation variations. Besides, the PVCs at short- and medium-temporal ranges were positively correlated with climate dryness, while negatively at longer temporal ranges. Moreover, the results suggested that the impact of climate on soil moisture dynamics at different time scales might vary across different climate zones, while soil effect was comparatively less in both regions. It provides additional insights into understanding soil moisture temporal dynamics in regions with contrasting climatic conditions.

Decadal high-resolution multi-proxy analysis to reconstruct natural and human-induced environmental changes over the last 1350 cal. yr BP in the Altai Tavan Bogd National Park, western Mongolia

The Holocene ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 1016-1028 ◽  
Author(s):  
Julia Unkelbach ◽  
Kaoru Kashima ◽  
Gaadan Punsalpaamuu ◽  
Lyudmila Shumilovskikh ◽  
Hermann Behling
Keyword(s):  
High Resolution ◽  
Water Availability ◽  
National Park ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
Permafrost Degradation ◽  
Rainfall Events ◽  
The Impact

The ‘Altai Tavan Bogd’ National Park in the north-western part of the Mongolian Altai, Central Asia, is located in a forest-steppe ecosystem. It occurs under the influence of extreme continental and montane climate and is sensitive to natural and anthropogenic impacts. High-resolution (<20 years per sample) multi-proxy data of pollen, non-pollen palynomorphs (NPPs), macro-charcoal, diatoms, and XRF scanning from radiocarbon-dated lacustrine sediments reveal various environmental changes and the impact of different settlement periods for the late-Holocene. From 1350 to 820 cal. yr BP (AD 600–1130), the distribution of grass steppe indicates a climate similar to present-day conditions. Rapid improvements of climatic conditions (e.g. increased rainfall events) possibly favored a recovery of forest-steppe encouraging nomadic movements into alpine areas. In the period from 820 to 400 cal. yr BP (AD 1130–1550), the decline of forested areas suggests an increasingly drier and possibly colder climate. Some political shifts during the Mongol Empire (744–582 cal. yr BP; AD 1206–1368) favored variations in nomadic grazing habits. After 400 cal. yr BP (AD 1550), moisture and temperature increased slightly, and from ca. 40 cal. yr BP (AD 1910) to present, annual temperature continued to increase more markedly favoring an additional water availability due to permafrost degradation. Diatom data suggest several intervals of increased water availability in all periods which might have caused erosion due to heavier rainfall events or increased snow melt. Immediately after most of these high-water intervals, NPP data reveal periods of increased grazing activities in the area.

scholarly journals The Impact of Rainfall on Soil Moisture Dynamics in a Foggy Desert

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0164982 ◽  
Author(s):  
Bonan Li ◽  
Lixin Wang ◽  
Kudzai F. Kaseke ◽  
Lin Li ◽  
Mary K. Seely
Keyword(s):  
Soil Moisture ◽  
Soil Moisture Dynamics ◽  
The Impact ◽  
Moisture Dynamics

scholarly journals Interpretation of ASCAT Radar Scatterometer Observations Over Land: A Case Study Over Southwestern France

2019 ◽  
Vol 11 (23) ◽  
pp. 2842 ◽  
Author(s):  
Daniel Shamambo ◽  
Bertrand Bonan ◽  
Jean-Christophe Calvet ◽  
Clément Albergel ◽  
Sebastian Hahn
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Extreme Event ◽  
Cloud Model ◽  
Large Fraction ◽  
Land Surface Model ◽  
Surface Model ◽  
Area Index ◽  
The Difference ◽  
The Impact

This paper investigates to what extent soil moisture and vegetation density information can be extracted from the Advanced Scatterometer (ASCAT) satellite-derived radar backscatter (σ°) in a data assimilation context. The impact of independent estimates of the surface soil moisture (SSM) and leaf area index (LAI) of diverse vegetation types on ASCAT σ° observations is simulated over southwestern France using the water cloud model (WCM). The LAI and SSM variables used by the WCM are derived from satellite observations and from the Interactions between Soil, Biosphere, and Atmosphere (ISBA) land surface model, respectively. They permit the calibration of the four parameters of the WCM describing static soil and vegetation characteristics. A seasonal analysis of the model scores shows that the WCM has shortcomings over karstic areas and wheat croplands. In the studied area, the Klaus windstorm in January 2009 damaged a large fraction of the Landes forest. The ability of the WCM to represent the impact of Klaus and to simulate ASCAT σ° observations in contrasting land-cover conditions is explored. The difference in σ° observations between the forest zone affected by the storm and the bordering agricultural areas presents a marked seasonality before the storm. The difference is small in the springtime (from March to May) and large in the autumn (September to November) and wintertime (December to February). After the storm, hardly any seasonality was observed over four years. This study shows that the WCM is able to simulate this extreme event. It is concluded that the WCM could be used as an observation operator for the assimilation of ASCAT σ° observations into the ISBA land surface model.

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