The properties and functions of biochars in forest ecosystems

Abstract

Purpose The production of large quantities of biochar from natural fires has been a part of human history for millennia, causing CO 2 emissions to the atmosphere and exerting longterm effects on soil processes. Despite its potential importance and recent work reflecting the wide interest in biochar, a general review of our deep understanding of biochar functions within forest soils is currently lacking. Gaps in research knowledge in this field are identified in this paper. Materials and methods This paper summarizes recent research to provide a better understanding of the concentrations, distribution, and characteristics of biochar produced from forest wildfire and its influences on soil processes. Perspectives and recommendations for future research on biochar in postfire forest soils are also discussed. Results and discussion The concentration, distribution, and characteristics of biochar produced from forest wildfire largely depend on forest landscapes, regional climates, and mostly its feedstock and fire history, like, its duration and severity. The influences of biochar on soil processes, particularly carbon and nitrogen transformations and cycling, like, nitrification and nitrous oxide emissions reduction (Clough and Condron, J Environ Qual 39:1218-1223, are also determined mainly by the fire temperature and raw materials. Mechanisms can be attributed to the adsorption of organic compounds and nutrients or changed microenvironment, termed as charsphere, by biochar. We also identify the microbial mechanisms involved in the biochar-containing soils.

Nitrosospira cluster 3-like bacterial ammonia oxidizers and Nitrospira-like nitrite oxidizers dominate nitrification activity in acidic terrace paddy soils

“…The nitrifying population in our study was closely related to soil pH ( Fig. 4), indicating the important role of pH in the selection and adaptation of particular phylogenetic nitrifying populations by determining the chemical form, availability and concentration of nitrification substrates (Curtin et al, 1998;Kemmitt et al, 2006;Nicol et al, 2008;Jiang et al, 2015;Luo et al, 2016). Soil OXC, representing the redox potential, also played a vital role in shaping the structure of the active nitrifying community in the complex soil environment (Fig.…”

Biochar influences nitrogen availability in Andisols of north Idaho forests

“…Biochar's effect on soil health and plant production has been intensively studied in agricultural ecosystem, whereas representations of forest, especially natural forest ecosystems, are lacking [7][8][9][10][11]. The few studies with controversial findings of soil nitrogen (N) mineralization response to biochar, as well as the general lack of knowledge in biochar effect overtime limit our understanding of the consequences in soil nutrient cycling following biochar application in forest ecosystems [12].…”

Long-Term Effect of Charcoal Accumulation in Hearth Soils on Tree Growth and Nutrient Cycling

“…Moreover, the residence time of biochar in soils is much longer than uncharred organic matter, persisting for centuries or even millennia (Spokas, 2010). Therefore, it is crucial to examine the long-term fate and impact of biochar on soil properties and vegetation, particularly in forest ecosystems (Li et al, 2018), which have been rarely investigated so far (Gundale et al, 2016;Luo et al, 2016).…”

“…In this respect, the recent interest in biochar was inspired by the study of Amazonian dark earths, whose genesis is closely related to the historical addition of fire residues to soil (Lehmann and Joseph, 2015). Similarly, two recent reviews on biochar application to forest ecosystems included studies dealing with natural charcoal produced during wildfires and accumulated in soil (Luo et al, 2016;Li et al, 2018). However, both models show limitations since Amazonian dark earths were also amended with inorganic and organic materials other than charcoal (Glaser and Birk, 2012), whereas differences in physico-chemical properties between anthropogenically and naturally produced charcoal raise the question if they can be really deemed as interchangeable in field studies (Santín et al, 2017).…”