Water Limitation in Forest Soils Regulates the Increase in Weathering Rates under Climate Change

Salim Belyazid,Giuliana Zanchi,Cecilia Akselsson

doi:10.3390/f13020310

Salim Belyazid, Giuliana Zanchi + Show 1 more

Open Access

https://doi.org/10.3390/f13020310

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Journal: Forests	Publication Date: Feb 14, 2022
Citations: 4	License type: CC BY 4.0

Affiliation: Lund University, Stockholm University

Abstract

Climate change is generally expected to have a positive effect on weathering rates, due to the strong temperature dependence of the weathering process. Important feedback mechanisms such as changes in soil moisture, tree growth and organic matter decomposition can affect the response of weathering rates to climate change. In this study, the dynamic forest ecosystem model ForSAFE, with mechanistic descriptions of tree growth, organic matter decomposition, weathering, hydrology and ion exchange processes, is used to investigate the effects of future climate scenarios on base cation weathering rates. In total, 544 productive coniferous forest sites from the Swedish National Forest Inventory are modelled, and differences in weathering responses to changes in climate from two Global Climate Models are investigated. The study shows that weathering rates at the simulated sites are likely to increase, but not to the extent predicted by a direct response to elevated air temperatures. Besides the result that increases in soil temperatures are less evident than those in air temperature, the study shows that soil moisture availability has a strong potential to limit the expected response to increased temperature. While changes in annual precipitation may not indicate further risk for more severe water deficits, seasonal differences show a clear difference between winters and summers. Taking into account the seasonal variation, the study shows that reduced soil water availability in the summer seasons will strongly limit the expected gain in weathering associated with higher temperatures.

Highlights

Received: 22 December 2021The use of the natural environment for economic activity has led to increasingly evident environmental impacts
As in other parts of Europe, Swedish forests have been exposed to acid atmospheric deposition [9,10], the effects of which can still be seen in acidified forest soils [11,12,13]
The release of base cations through the weathering of minerals in ForSAFE is based on the PROFILE model [22]

Summary

Introduction

Received: 22 December 2021The use of the natural environment for economic activity has led to increasingly evident environmental impacts. These impacts are manifested through the exceedance of the planetary boundaries [1], including climate change [2]. Awareness of these impacts is driving a shift away from conventional, linear resource use to a circular, bio-based economy [3]. Higher levels of biomass harvesting from forests may, compromise the sustainability of forest ecosystems [8]. Forest soil acidification may be further exacerbated by the removal of alkaline cations though biomass harvesting [11,14,15,16]. Iwald et al [11]

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