Leaching of metals from forest soils as influenced by tree species and management

Despite the general agreement that maximizing carbon storage and its persistence in forest soils are top priorities in the context of climate change mitigation, our knowledge on how to steer soil organic carbon (SOC) through forest management remains limited. For some soils, tree species selection based on litter quality has been shown a powerful measure to boost SOC stocks and stability, whereas on other locations similar efforts result in insignificant or even opposite effects. A better understanding of which mechanisms underpin such context-dependency is needed in order to focus and prioritize management efforts for carbon sequestration. Here we discuss the key role of acid buffering mechanisms in belowground ecosystem functioning and how threshold behavior in soil pH mediates tree species effects on carbon cycling. For most forests around the world, the threshold between the exchange buffer and the aluminum buffer around a pH-H2O of 4.5 is of particular relevance. When a shift between these buffer domains occurs, it triggers changes in multiple compartments in the soil, ultimately altering the way carbon is incorporated and transformed. Moreover, the impact of such a shift can be amplified by feedback loops between tree species, soil biota and cation exchange capacity (CEC). Hence, taking into account non-linearities related to acidity will allow more accurate predictions on the size and direction of the effect of litter quality changes on the way soil organic carbon is stored in forest soils. Consequently, this will allow developing more efficient, context-explicit management strategies to optimize SOC stocks and their stability.

Download Full-text

Composition and mineralization of soil organic carbon pools in four single-tree species forest soils

Journal of Forestry Research ◽

10.1007/s11676-016-0244-z ◽

2016 ◽

Vol 27 (6) ◽

pp. 1277-1285 ◽

Cited By ~ 4

Author(s):

Qingkui Wang ◽

Micai Zhong

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Soils ◽

Tree Species ◽

Carbon Pools ◽

Single Tree ◽

Soil Organic Carbon Pools

Download Full-text

Molecular size distribution and hydrophilic and hydrophobic properties of humic acids isolated from forest soil

Soil and Water Research ◽

10.17221/2113-swr ◽

2008 ◽

Vol 2 (No. 2) ◽

pp. 45-53 ◽

Cited By ~ 8

Author(s):

B. Debska ◽

M. Drag ◽

M. Banach-Szott

Keyword(s):

Humic Acids ◽

Forest Soils ◽

Tree Species ◽

Plant Material ◽

Molecular Size ◽

European Beech ◽

Plant Litter ◽

Hydrophobic Properties ◽

Degree Of Maturity ◽

Molecular Size Distribution

The aim of the present paper was to determine hydrophilic and hydrophobic properties and the degree of polydispersity of humic acids depending on their degree of maturity and the properties of the plant material participating in the process of humification. The study involved humic acids isolated from samples taken from organic and mineral horizons of forest soils. The samples were taken under the tree stands of: pine with an admixture of hardbeam, European beech, elm, fir, spruce, and thuja. It was demonstrated that the properties of humic acids of the organic horizon and mineral horizons are determined by the kind of plant litter, mainly by the tree species. The humification process is connected with an increase of the proportion of humic acids of lower molecular size as compared to the proportion of molecules greater in size, and with an increase of hydrophilic fractions and a decrease of hydrophobic fractions. Based on the correlation relationships, it was shown that the degree of polydispersity of molecules of humic acids is related to their hydrophilic and hydrophobic properties. Humic acids with a larger proportion of high-molecular fractions demonstrate also a higher proportion of hydrophobic fractions.

Download Full-text

Influence of tree species on gross and net N transformations in forest soils

Annals of Forest Science ◽

10.1051/forest:2006099 ◽

2007 ◽

Vol 64 (2) ◽

pp. 151-158 ◽

Cited By ~ 35

Author(s):

Bernd Zeller ◽

Sylvie Recous ◽

Morgan Kunze ◽

Judicaël Moukoumi ◽

Micheline Colin-Belgrand ◽

...

Keyword(s):

Forest Soils ◽

Tree Species ◽

N Transformations

Download Full-text

How Can Litter Modify the Fluxes of CO2 and CH4 from Forest Soils? A Mini-Review

Forests ◽

10.3390/f12091276 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1276

Author(s):

Anna Walkiewicz ◽

Adrianna Rafalska ◽

Piotr Bulak ◽

Andrzej Bieganowski ◽

Bruce Osborne

Keyword(s):

Climate Change ◽

Forest Soils ◽

Tree Species ◽

Water Movement ◽

C Sequestration ◽

Climatic Conditions ◽

Tree Species Composition ◽

Clear Cutting ◽

And Shifts ◽

The Impact

Forests contribute strongly to global carbon (C) sequestration and the exchange of greenhouse gases (GHG) between the soil and the atmosphere. Whilst the microbial activity of forest soils is a major determinant of net GHG exchange, this may be modified by the presence of litter through a range of mechanisms. Litter may act as a physical barrier modifying gas exchange, water movement/retention and temperature/irradiance fluctuations; provide a source of nutrients for microbes; enhance any priming effects, and facilitate macro-aggregate formation. Moreover, any effects are influenced by litter quality and regulated by tree species, climatic conditions (rainfall, temperature), and forest management (clear-cutting, fertilization, extensive deforestation). Based on climate change projections, the importance of the litter layer is likely to increase due to an litter increase and changes in quality. Future studies will therefore have to take into account the effects of litter on soil CO2 and CH4 fluxes for various types of forests globally, including the impact of climate change, insect infestation, and shifts in tree species composition, as well as a better understanding of its role in monoterpene production, which requires the integration of microbiological studies conducted on soils in different climatic zones.

Download Full-text