Responses of soil water percolation to dynamic interactions among rainfall, antecedent moisture and season in a forest site

2016 ◽  
Vol 540 ◽  
pp. 565-573 ◽  
Author(s):  
Xiaoming Lai ◽  
Kaihua Liao ◽  
Huihui Feng ◽  
Qing Zhu
Keyword(s):  
Soil Water ◽  
Forest Site ◽  
Dynamic Interactions ◽  
Antecedent Moisture ◽  
Water Percolation

scholarly journals Evaluating the E3SM land model version 0 (ELMv0) at a temperate forest site using flux and soil water measurements

2019 ◽  
Vol 12 (4) ◽  
pp. 1601-1612 ◽  
Author(s):  
Junyi Liang ◽  
Gangsheng Wang ◽  
Daniel M. Ricciuto ◽  
Lianhong Gu ◽  
Paul J. Hanson ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Soil Water ◽  
Water Retention ◽  
Water Retention Curve ◽  
Forest Site ◽  
Earth System ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
Growing Seasons

Abstract. Accurate simulations of soil respiration and carbon dioxide (CO2) fluxes are critical to project global biogeochemical cycles and the magnitude of carbon–climate feedbacks in Earth system models (ESMs). Currently, soil respiration is not represented well in ESMs, and few studies have attempted to address this deficiency. In this study, we evaluated the simulation of soil respiration in the Energy Exascale Earth System Model (E3SM) land model version 0 (ELMv0) using long-term observations from the Missouri Ozark AmeriFlux (MOFLUX) forest site in the central US. Simulations using the default model parameters underestimated soil water potential (SWP) during peak growing seasons and overestimated SWP during non-growing seasons and consequently underestimated annual soil respiration and gross primary production (GPP). A site-specific soil water retention curve greatly improved model simulations of SWP, GPP, and soil respiration. However, the model continued to underestimate the seasonal and interannual variabilities and the impact of the extreme drought in 2012. Potential reasons may include inadequate representations of vegetation mortality, the soil moisture function, and the dynamics of microbial organisms and soil macroinvertebrates. Our results indicate that the simulations of mean annual GPP and soil respiration can be significantly improved by better model representations of the soil water retention curve.

scholarly journals Litter and deadwood water retention processes in a temperate mixed forest

2021 ◽  
Author(s):  
Marius G. Floriancic ◽  
Scott T. Allen ◽  
Peter Molnar
Keyword(s):  
Soil Water ◽  
Forest Floor ◽  
Water Retention ◽  
Storage Capacity ◽  
Soil Layer ◽  
Mixed Forest ◽  
Water Retention Capacity ◽  
Forest Site ◽  
Retention Capacity ◽  
Temperate Mixed Forest

<p>Countless studies have demonstrated ways in which forests and trees affect catchment water balances. Water balance differences between forested and non-forested landscapes are often attributed to characteristics related to trees’ ability to take up and transpire water, as well as their ability to intercept precipitation. However, another potentially important characteristic of forests that has been largely overlooked in hydrologic studies is the retention and accumulation of debris, litter and deadwood on the forest floor. Here we leverage ongoing measurements at the new hillslope laboratory “Waldlabor” in Zurich, Switzerland, where water retention in forest litter, deadwood and the top soil layer has been investigated using frequent field campaigns and innovative new sensing techniques.</p><p>Several approaches were used to determine the maximum storage capacity as well as the storage dynamics of different types and layers of litter. In-lab saturation experiments revealed the maximum storage capacity of various litter types (i.e., leaf and needle litter). Those values were also supported with field pre- and post- rainfall sampling campaigns to determine in-situ litter storage dynamics, as well as to understand the interplay between litter interception and soil-water recharge. Importantly, recharge was often substantially smaller at plots with litter, compared to those without litter. The storage and water retention capacity of deadwood samples was measured in the field by logging the diurnal differences in deadwood weight over a six month period. Dew and fog deposition during the night led to larger water availability for evaporation during the day. We measured increased humidity at sensors in the forest at 1 and 3m heights respectively, compared to the humidity outside the forest. Daily weight measurements over eight weeks of 40 deadwood pieces at our forest site revealed differences in the storage capacity depended on the degree of decomposition. Additionally, we found that water stored in forest floor spruce cones (daily measurements of 20 pieces) actively contributed to evaporation fluxes.</p><p>The combination of continuous sensor measurements (soil moisture, deadwood water content), field measurements (litter and deadwood grab samples) as well as laboratory work (saturation experiments) revealed the water storage and retention capacity of litter and deadwood in a typical temperate mixed forest and their contribution to evaporation. These measurements are one component of the new ETH Zürich “Waldlabor” research infrastructure, which also includes measurements of precipitation, xylem water, soil water, groundwater, and discharge amounts, isotope ratios, and other chemical characteristics.</p>

scholarly journals Modelling the artificial forest (<i>Robinia pseudoacacia</i> L.) root–soil water interactions in the Loess Plateau, China

2022 ◽  
Vol 26 (1) ◽  
pp. 17-34
Author(s):  
Hongyu Li ◽  
Yi Luo ◽  
Lin Sun ◽  
Xiangdong Li ◽  
Changkun Ma ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Loess Plateau ◽  
Water Uptake ◽  
Growth Models ◽  
Robinia Pseudoacacia ◽  
Rooting Depth ◽  
Climatic Data ◽  
Forest Site ◽  
The Loess Plateau

Abstract. Plant root–soil water interactions are fundamental to vegetation–water relationships. Soil water availability and distribution impact the temporal–spatial dynamics of roots and vice versa. In the Loess Plateau (LP) of China, where semi-arid and arid climates prevail and deep loess soil dominates, drying soil layers (DSLs) have been extensively reported in artificial forestland. While the underlying mechanisms that cause DSLs remain unclear, they hypothetically involve root–soil water interactions. Although available root growth models are weak with respect to simulating the rooting depth, this study addresses the hypothesis of the involvement of root–soil water interactions in DSLs using a root growth model that simulates both the dynamic rooting depth and fine-root distribution, coupled with soil water, based on cost–benefit optimization. Evaluation of field data from an artificial black locust (Robinia pseudoacacia L.) forest site in the southern LP positively proves the model's performance. Further, a long-term simulation, forced by a 50-year climatic data series with varying precipitation, was performed to examine the DSLs. The results demonstrate that incorporating the dynamic rooting depth into the current root growth models is necessary to reproduce soil drying processes. The simulations revealed that the upper boundary of the DSLs fluctuates strongly with infiltration events, whereas the lower boundary extends successively with increasing rooting depth. Most infiltration was intercepted by the top 2.0 m layer, which was the most active zone of infiltration and root water uptake. Below this, the percentages of fine roots (5.0 %) and water uptake (6.2 %) were small but caused a persistently negative water balance and consequent DSLs. Therefore, the proposed root–water interaction approach succeeded in revealing the intrinsic properties of DSLs; their persistent extension and the lack of an opportunity for recovery from the drying state may adversely affect the implementation of artificial afforestation in this region as well as in other regions with similar climates and soils.

Surface runoff and soil water percolation as affected by snow and soil frost

1991 ◽  
Vol 122 (1-4) ◽  
pp. 141-159 ◽  
Author(s):  
Holger Johnsson ◽  
Lars-Christer Lundin
Keyword(s):  
Soil Water ◽  
Surface Runoff ◽  
Soil Frost ◽  
Water Percolation

scholarly journals Mapeamento da Caatinga com Uso de Geotecnologia e Análise da Umidade Antecedente em Bacia Hidrográfica (Mapping of Caatinga with Use of Geotechnology and Analysis of Antecedent Humidity in Hydrographic Basin)

2012 ◽  
Vol 5 (3) ◽  
pp. 676 ◽  
Author(s):  
Paulo Roberto Megma Francisco ◽  
Iêde De Brito Chaves ◽  
Eduardo Rodrigues Viana de Lima ◽  
Maria Marle Bandeira ◽  
Bernardo Barbosa da Silva
Keyword(s):  
Soil Water ◽  
Water Availability ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Soil Water Availability ◽  
Semiarid Region ◽  
Hydrographic Basin ◽  
Antecedent Moisture ◽  
Caatinga Vegetation ◽  
Medium Resolution

O estado da Paraíba tem como característica climática marcante as irregularidades, tanto espacial quanto temporal do seu regime de chuvas, uma vez que, 86,6% do seu território faz parte da região semiárida brasileira. A cobertura vegetal de caatinga, já bastante impactada pela ação antrópica, apresenta diferentes feições relacionadas aos fatores edafoclimáticos, dentre estes, a precipitação, que influenciada pelo relevo, tende a aumentar com a altitude dentro dos diferentes espaços hidrogeográficos. Quanto menor a precipitação, maior a aridez e a irregularidade da distribuição das chuvas. No período seco, a maioria das plantas da caatinga perde a folhagem, recompondo-se rapidamente, logo que inicia um novo período de chuva. Este trabalho teve como objetivo analisar a influência da umidade antecedente em imagem orbital de média resolução espacial e utilizada para mapeamento da vegetação de caatinga através do Índice de Vegetação de Diferença Normalizada e o Índice de Biomassa da Vegetação Lenhosa. Concluiu-se que com a utilização de imagem de média resolução espacial a classificação em 9 classes foi satisfatória na separação das fisionomias existentes na região estudada; que a análise da diferença espectral pode contribuir no monitoramento; que houve influência da umidade antecedente nas respostas espectrais; que a biomassa da vegetação de caatinga está relacionada à disponibilidade de água no solo; e com o uso de geotecnologia pode-se chegar a resultados satisfatórios.Palavras - chave: Semiárido, índice de vegetação, sensoriamento remoto. Mapping of Caatinga with Use of Geotechnology and Analysis of Antecedent Humidity in Hydrographic Basin ABSTRACTThe state of Paraíba is characterized by striking climatic irregularities, both its spatial and temporal rainfall, since 86.6% of its territory is part of the Brazilian semiarid region. The vegetation of caatinga, enough already impacted by human activity, has different features related to soil and climatic factors, among these, the precipitation, which influenced by the relief, tends to increase with altitude within the different spaces hidrogeografic. The lower rainfall, increased aridity and the irregularity of rainfall distribution. In the dry season, most plants of the caatinga lose foliage, recovering quickly, as soon as you start a new period of rain. Generally, the quantity and persistence of hardwood biomass from caatinga vegetation is related to soil water availability. This study aimed to analyze the influence of antecedent moisture on multispectral image captured by the sensor and medium resolution satellite used for mapping of caatinga vegetation using NDVI and IBVL. It was concluded by this study that the use of medium-resolution image, the classification in nine classes was satisfactory in the separation the physiognomies in the region studied, which of the difference spectral analysis can help in monitoring and there was no influence of antecedent humidity on spectral responses, that biomass of caatinga vegetation is related to soil water availability, and the use of geotechnology can be reached satisfactory results.Keywords: Semiarid, vegetation index, remote sensing.

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