Quantification of Phosphorus Exports from a Small Forested Headwater-Catchment in the Eastern Ore Mountains, Germany

Abstract

Phosphorus (P) export from forest soils is mainly driven by storm events, which induce rapid flow processes by preferential flow bypassing large parts of the soil matrix. However, little is known about the dynamics, magnitude, and driving processes of P exports into surface waters. In this paper, we present the results of a monitoring study in a small forested catchment (21 ha) situated in the low mountain ranges of Saxony, Germany. During the fixed schedule-sampling (weekly to bi-weekly sampling frequency for a three-year period), a mean total-P concentration of 8 µg·L −1 was measured. However, concentrations increased up to 203 µg·L −1 during individual storm flow events. Based on the analyzed concentrations and continuously measured discharge we calculated mean annual export rates of 19 to 44 g·ha −1 ·a −1 for the weekly sampling frequency with different load calculation methods. If events are included into the annual load calculation, the mean annual export fluxes can be up to 83 g·ha −1 ·a −1 based on the different load calculation methods. Predictions of total-P export rates based on a sampling strategy which does not consider short-term changes due to factors such as storms will substantially underestimate P exports.

Leaching of dissolved and particulate phosphorus via preferential flow pathways in a forest soil: An approach using zero‐tension lysimeters

“…After the installation of the samplers, the trenches and the soil above the samplers were covered with tarpaulins to simulate a dry summer period without rainfall of four weeks. According to Kaiser et al (2003), Julich et al (2017c), and other investigators, high-intensity rain events following a dry period have the highest potential for P translocations in forest soils.…”

“…However, recent studies have indicated that transport via preferential flow pathways might be crucial for P transport in and export from forest soils (Julich et al, 2017a;2017b). Correll et al (1999) and Julich et al (2017c) highlighted the link between storm events after dry periods and a significant rise of P concentrations in stream water, indicating that there are significant P losses from forest ecosystems.…”

Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

“…The occurrence and development of preferential flow in the soil are closely related to water, transport, and the accumulation of nutrients in the soil [57,58]. In this study, we used SPSS to calculate the soil nutrients and characteristic parameters of preferential flow to study the correlation between preferential flow and the accumulation of soil nutrients ( Table 7).…”

Influence of Root Distribution on Preferential Flow in Deciduous and Coniferous Forest Soils

“…Preferential flow, without conforming to Darcy's flow, is well recognized as a potentially important mechanism in soils [1][2][3]. This kind of flow can increase the leaching potential of soils and limit the storage, filter, and buffer functions of soils, and associate with a large number of inaccuracies in water and solute transport predictions [4][5][6][7][8][9][10]. Continuous root channels can generate preferential flow paths, and promote movement of water and solutes with little resistance [11][12][13][14][15].…”