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The Effects and Fate of Inorganic Nitrogen Inputs to Oligotrophic Peat Soils
Published in Carl C. Trettin, Martin F. Jurgensen, David F. Grigal, Margaret R. Gale, John K. Jeglum, Northern Forested Wetlands, 2018
Berwyn L. Williams, Deborah J. Silcock
Dissolved organic N has received relatively little attention in soil N investigations, and its origin is not clear. In forest soils, throughfall can be enriched or depleted in soluble organic matter (Qualls et al., 1991), and other vegetation canopies behave in a similar way (Seastedt, 1985). Throughfall can also become enriched in soluble organic matter passing through the litter layer on the forest floor (Brown and Iles, 1991). Death and decay of microorganisms may also contribute to the soluble organic fraction. The mobility of this pool and its mineralization could have important implications for the eutrophication of surface waters. Studies on the composition of runoff waters draining a reseeded blanket bog showed that the organic component far exceeded the inorganic N fraction (Williams and Edwards, 1993).
Forests, Man and Water
Published in J. Rose, Water and the Environment, 2017
The vegetation canopy intercepts a proportion of the incident rainfall and may also serve as a collector for water droplets which are too small to precipitate directly in the moving air and are carried horizontally. This has been termed “occult precipitation” for it will not be recorded by conventional rain gauges4 and may increase the water input to the ecosystem by 25 percent. Water on the leaves may pass on to the forest floor as throughfall, run down twigs to be concentrated as stemflow, or may be absorbed by the leaf itself. Such foliar absorption is of considerable importance to plants in climates where water is scarce,5 such is the case with the fog-collecting leaves of Welwitschia mirabilis in the Namib desert of south-west Africa.
Introduction to Watershed Management
Published in Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose, Watershed Management and Applications of AI, 2021
Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose
The process which describes how wet leaves shed excess water onto the ground surface is known as throughfall. This loss occurs because of evaporation which does not consist of transpiration and throughfall.
Assessment of rainfall interception, soil moisture dynamics and seasonal headwaters in a micro-catchment of Western ghats
Published in Water Science, 2023
A portion of incoming rainfall that is intercepted, stored, and evaporated from the leaves and stems of vegetation is called rainfall interception loss. Excess rainfall passing through the canopy after canopy storage reaches the ground is called throughfall. Gross rainfall is the precipitation that is falling over the canopy without any obstructions. Gross rainfall (GRF) is measured by placing the rain gauge above the canopy on a tower. But it is often expensive to set up a tower; therefore, it is measured on the ground in an open space near the interception measurement site. The ratio of TF to GRF represents the amount of precipitation reaching the ground surface passing through vegetation. The overall average of the ratios TF/GRF will give the average interception in the annual water balance estimates.
Mercury fluxes, budgets, and pools in forest ecosystems of China: A review
Published in Critical Reviews in Environmental Science and Technology, 2020
Jun Zhou, Buyun Du, Lihai Shang, Zhangwei Wang, Hongbiao Cui, Xingjun Fan, Jing Zhou
Throughfall and litterfall depositions are the two major pathways for Hg delivery to forest floor. Throughfall is rainfall that delivers Hg to the forest floor after interacting with the forest canopy, which can wash off a large portion of the PBM and GOM deposited on forest leaves (Rea, Lindberg, & Keeler, 2000), resulting in higher THg and MeHg concentrations compared to those in precipitation. Throughfall THg concentrations and depositions are influenced by many factors, such as canopy type (Demers, Driscoll, Fahey, & Yavitt, 2007), meteorological conditions (Blackwell & Driscoll, 2015a), and sample locations (Yao Luo, Duan, Xu, & Hao, 2015). In addition, THg concentrations in precipitations also significantly affected these in throughfall due to similar source in both aqueous, which showed a significant positive correlation (n = 10, r2 = 0.74, p < .01). The THg concentrations ranged from 8.9 to 40.2 ng L−1 (n = 5, mean = 23.5 ng L−1) at remote forests and from 20.1 to 69.7 ng L−1 (n = 6, mean = 42.0 ng L−1) at rural and suburban forests, which averaged 1.9- and 2.3-fold compared to the corresponding THg concentrations in precipitation (Table 1).