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Soil carbon is the solid
carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
stored in global
soils
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term ...
. This includes both
soil organic matter Soil organic matter (SOM) is the organic matter component of soil, consisting of plant and animal detritus at various stages of decomposition, cells and tissues of soil microbes, and substances that soil microbes synthesize. SOM provides numerous b ...
and
inorganic
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...
carbon as
carbonate minerals
Carbonate minerals are those minerals containing the carbonate ion, .
Carbonate divisions Anhydrous carbonates
*Calcite group: trigonal
**Calcite CaCO3
**Gaspéite (Ni,Mg,Fe2+)CO3
**Magnesite MgCO3
**Otavite CdCO3
**Rhodochrosite MnCO3
**Sider ...
.
Soil carbon is a
carbon sink
A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide () from the atmosphere.
Globally, the two most important carbon si ...
in regard to the global
carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and Earth's atmosphere, atmosphere of the Earth. Carbon is the main component of biological compounds as well as ...
, playing a role in
biogeochemistry
Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, t ...
,
climate change mitigation
Climate change mitigation is action to limit climate change by reducing Greenhouse gas emissions, emissions of greenhouse gases or Carbon sink, removing those gases from the atmosphere. The recent rise in global average temperature is mostly caus ...
, and constructing global
climate model
Numerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the cl ...
s.
Overview
Soil carbon is present in two forms: inorganic and organic. Soil inorganic carbon consists of mineral forms of carbon, either from
weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...
of
parent material
Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are ...
, or from reaction of soil minerals with atmospheric CO
2.
Carbonate minerals
Carbonate minerals are those minerals containing the carbonate ion, .
Carbonate divisions Anhydrous carbonates
*Calcite group: trigonal
**Calcite CaCO3
**Gaspéite (Ni,Mg,Fe2+)CO3
**Magnesite MgCO3
**Otavite CdCO3
**Rhodochrosite MnCO3
**Sider ...
are the dominant form of soil carbon in
desert climate
The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk''), is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert ...
s.
Soil organic carbon
Soil carbon is the solid carbon stored in global soils. This includes both soil organic matter and inorganic carbon as carbonate minerals. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, clim ...
is present as
soil organic matter Soil organic matter (SOM) is the organic matter component of soil, consisting of plant and animal detritus at various stages of decomposition, cells and tissues of soil microbes, and substances that soil microbes synthesize. SOM provides numerous b ...
. It includes relatively available carbon as fresh plant remains and relatively inert carbon in materials derived from plant remains:
humus
In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...
and
charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...
.
Global carbon cycle
Although exact quantities are difficult to measure, human activities have caused substantial losses of soil organic carbon.
Of the 2,700 Gt of carbon stored in soils worldwide, 1550 GtC is organic and 950 GtC is inorganic carbon, which is approximately three times greater than the current atmospheric carbon and 240 times higher compared with the current annual fossil fuel emission. The balance of soil carbon is held in
peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...
and wetlands (150 GtC), and in
plant litter
Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...
at the soil surface (50 GtC). This compares to 780 GtC in the
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
, and 600 GtC in
all living organisms. The oceanic pool of carbon accounts for 38,200 GtC.
About 60 GtC/yr accumulates in the soil. This 60 GtC/yr is the balance of 120 GtC/yr
contracted from the atmosphere by terrestrial plant
photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
reduced by 60 GtC/yr of plant
respiration
Respiration may refer to:
Biology
* Cellular respiration, the process in which nutrients are converted into useful energy in a cell
** Anaerobic respiration, cellular respiration without oxygen
** Maintenance respiration, the amount of cellula ...
. An equivalent 60 GtC/yr is respired from soil, joining the 60G tC/yr plant respiration to return to the atmosphere.
Organic carbon
Soil organic carbon
Soil carbon is the solid carbon stored in global soils. This includes both soil organic matter and inorganic carbon as carbonate minerals. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, clim ...
is divided between living
soil biota
Soil biology is the study of microbial and faunal activity and ecology in soil.
Soil life, soil biota, soil fauna, or edaphon is a collective term that encompasses all organisms that spend a significant portion of their life cycle within a soil ...
and dead
biotic material
Biotic material or biological derived material is any material that originates from living organisms. Most such materials contain carbon and are capable of decay.
The earliest life on Earth arose at least 3.5 billion years ago.Schopf, JW, Kudrya ...
derived from biomass. Together these comprise the
soil food web
The soil food web is the community of organisms living all or part of their lives in the soil. It describes a complex living system in the soil and how it interacts with the environment, plants, and animals.
Food webs describe the transfer of en ...
, with the living component
sustained by the biotic material component. Soil biota includes
earthworms
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...
,
nematodes
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...
,
protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...
,
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
,
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
and different
arthropods
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
.
Detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...
resulting from
plant senescence
Plant senescence is the process of aging in plants. Plants have both stress-induced and age-related developmental aging. Chlorophyll degradation during leaf senescence reveals the carotenoids, such as anthocyanin and xanthophylls, which are the ...
is the major source of soil organic carbon. Plant materials, with
cell wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mech ...
s high in
cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
and
lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity ...
, are decomposed and the not-
respired carbon is retained as
humus
In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...
. Cellulose and starches readily degrade, resulting in short residence times. More persistent forms of organic C include lignin, humus, organic matter encapsulated in soil aggregates, and charcoal. These resist alteration and have long residence times.
Soil organic carbon tends to be concentrated in the topsoil.
Topsoil
Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.
Description
Topsoil is composed of mineral particles and organic matt ...
ranges from 0.5% to 3.0% organic carbon for most
upland soils. Soils with less than 0.5% organic C are mostly limited to
desert
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
areas. Soils containing greater than 12–18% organic carbon are generally classified as
organic soils. High levels of organic C
develop in soils supporting
wetland ecology,
flood deposition,
fire ecology
Fire ecology is a scientific discipline concerned with natural processes involving fire in an ecosystem and the ecological effects, the interactions between fire and the abiotic and biotic components of an ecosystem, and the role as an ecosystem p ...
, and
human activity
Human behavior is the potential and expressed capacity ( mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Kagan, Jerome, Marc H. Bornstein, and Richard M. L ...
.
Fire derived forms of carbon are present in most soils as unweathered
charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...
and weathered
black carbon
Chemically, black carbon (BC) is a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter). Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fue ...
. Soil organic carbon is typically 5–50% derived from char, with levels above 50% encountered in
mollisol
Mollisol is a soil type which has deep, high organic matter, nutrient-enriched surface soil (a horizon), typically between 60 and 80 cm in depth. This fertile surface horizon, called a mollic epipedon, is the defining diagnostic feature of M ...
,
chernozem
Chernozem (from rus, чернозём, p=tɕɪrnɐˈzʲɵm, r=chernozyom; "black ground"), also called black soil, is a black-colored soil containing a high percentage of humus (4% to 16%) and high percentages of phosphorus and ammonia compoun ...
, and
terra preta
''Terra preta'' (, locally , literally "black soil" in Portuguese) is a type of very dark, fertile anthropogenic soil ( anthrosol) found in the Amazon Basin. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its ful ...
soils.
Root exudates are another source of soil carbon. 5–20% of the total plant carbon fixed during photosynthesis is supplied as root exudates in support of
rhizospheric mutualistic biota. Microbial populations are typically higher in the rhizosphere than in adjacent
bulk soil Bulk soil is soil outside the rhizosphere that is not penetrated by plant roots. The bulk soil is like an ecosystem, it is made up of many things such as: nutrients, ions, soil particles, and root exudates. There are many different interactions that ...
.
Soil health
Organic carbon is vital to soil capacity to provide
edaphic
Edaphology (from Greek , ''edaphos'', "ground",, ''-logia'') is concerned with the influence of soils on living beings, particularly plants.
It is one of two main divisions of soil science, the other being pedology. Edaphology includes the study ...
ecosystem services
Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. Th ...
. The condition of this capacity is termed
soil health
Soil health is a state of a soil meeting its range of ecosystem functions as appropriate to its environment. In more colloquial terms, the health of soil arises from favorable interactions of all soil components (living and non-living) that belong ...
, a term that communicates the value of understanding soil as a living system as opposed to an
abiotic component
In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them und ...
. Specific carbon related benchmarks used to evaluate soil health include CO
2 release, humus levels, and microbial metabolic activity.
Losses
The exchange of carbon between soils and the atmosphere is a significant part of the world carbon cycle. Carbon, as it relates to the organic matter of soils, is a major component of soil and
catchment
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...
health. Several factors affect the variation that exists in soil organic matter and soil carbon; the most significant has, in contemporary times, been the influence of humans and agricultural systems.
Although exact quantities are difficult to measure, human activities have caused massive losses of soil organic carbon.
[ First was the use of ]fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
At a certain point in the combustion reaction, called the ignition ...
, which removes soil cover and leads to immediate and continuing losses of soil organic carbon. Tillage
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoein ...
and drainage
Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic conditio ...
both expose soil organic matter to oxygen and oxidation. In the Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
, East Anglia
East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...
, Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, and the California Delta
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, subsidence of peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...
lands from oxidation has been severe as a result of tillage and drainage. Grazing
In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...
management that exposes soil (through either excessive or insufficient recovery periods) can also cause losses of soil organic carbon.
Managing soil carbon
Natural variations in soil carbon occur as a result of climate
Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologic ...
, organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
s, parent material
Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are ...
, time, and relief. The greatest contemporary influence has been that of humans; for example, carbon in Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
n agricultural
Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...
soils may historically have been twice the present range that is typically from 1.6 to 4.6 per cent.
It has long been encouraged that farmers adjust practices to maintain or increase the organic component in the soil. On one hand, practices that hasten oxidation of carbon (such as burning crop stubbles or over-cultivation) are discouraged; on the other hand, incorporation of organic material (such as in manuring) has been encouraged. Increasing soil carbon is not a straightforward matter; it is made complex by the relative activity of soil biota, which can consume and release carbon and are made more active by the addition of nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s.[
]
Data available on soil organic carbon
=Europe
=
The most homogeneous and comprehensive data on the organic carbon/matter content of Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
an soils remain those that can be extracted and/or derived from the European Soil Database in combination with associated databases on land cover
Land cover is the physical material at the surface of Earth. Land covers include grass, asphalt, trees, bare ground, water, etc. Earth cover is the expression used by ecologist Frederick Edward Clements that has its closest modern equivalent being ...
, climate, and topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps.
Topography is a field of geoscience and planetary sci ...
. The modelled data refer t
carbon content (%) in the surface horizon
of soils in Europe. In an inventory on available national datasets, seven member states of the European Union have available datasets on organic carbon. In the article
Estimating soil organic carbon in Europe based on data collected through a European network
(Ecological Indicators 24, pp. 439–450), a comparison of national data with modelled data is performed. The LUCAS soil organic carbon data are measured surveyed points and the aggregated results at regional level show important findings. Finally, a new proposed model for estimation of soil organic carbon in agricultural soils has estimated current to
SOC stock of 17.63 Gt
in EU agricultural soils. This modelling framework has been updated by integrating the soil erosion component to estimate the lateral carbon fluxes.
Managing for catchment health
Much of the contemporary literature on soil carbon relates to its role, or potential, as an atmospheric carbon sink
A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide () from the atmosphere.
Globally, the two most important carbon si ...
to offset climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
. Despite this emphasis, a much wider range of soil and catchment
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...
health aspects are improved as soil carbon is increased. These benefits are difficult to quantify, due to the complexity of natural resource
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest and cultural value. O ...
systems and the interpretation of what constitutes soil health; nonetheless, several benefits are proposed in the following points:
*Reduced erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
, sedimentation
Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the ...
: increased soil aggregate stability means greater resistance to erosion; mass movement is less likely when soils are able to retain structural strength under greater moisture levels.
*Greater productivity: healthier and more productive soils can contribute to positive socio-economic circumstances.
*Cleaner waterway
A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary b ...
s, nutrients and turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality.
Fluids can ...
: nutrients and sediment tend to be retained by the soil rather than leach or wash off, and are so kept from waterways.
*Water balance
The law of water balance states that the inflows to any water system or area is equal to its outflows plus change in storage during a time interval. In hydrology, a water balance equation can be used to describe the flow of water in and out of ...
: greater soil water holding capacity reduces overland flow and recharge to groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...
; the water saved and held by the soil remains available for use by plants.
*Climate change: Soils have the ability to retain carbon that may otherwise exist as atmospheric CO2 and contribute to global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
.
*Greater biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...
: soil organic matter contributes to the health of soil flora and, accordingly, the natural links with biodiversity in the greater biosphere
The biosphere (from Greek βίος ''bíos'' "life" and σφαῖρα ''sphaira'' "sphere"), also known as the ecosphere (from Greek οἶκος ''oîkos'' "environment" and σφαῖρα), is the worldwide sum of all ecosystems. It can also be ...
.
Forest soils
Forest
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
soils constitute a large pool of carbon. Anthropogenic activities such as deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
cause releases of carbon from this pool, which may significantly increase the concentration of greenhouse gas
A greenhouse gas (GHG or GhG) is a gas that Absorption (electromagnetic radiation), absorbs and Emission (electromagnetic radiation), emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse ...
(GHG) in the atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
. Under the United Nations Framework Convention on Climate Change
The United Nations Framework Convention on Climate Change (UNFCCC) established an international environmental treaty to combat "dangerous human interference with the climate system", in part by stabilizing greenhouse gas concentrations in th ...
(UNFCCC), countries must estimate and report GHG emissions and removals, including changes in carbon stocks in all five pools (above- and below-ground biomass, dead wood, litter, and soil carbon) and associated emissions and removals from land use, land-use change and forestry activities, according to the Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to advance scientific knowledge about climate change caused by human activities. The World Meteorological Organization (WMO) a ...
's good practice guidance. Tropical deforestation represents nearly 25 percent of total anthropogenic GHG emissions worldwide. Deforestation, forest degradation, and changes in land management practices can cause releases of carbon from soil to the atmosphere. For these reasons, reliable estimates of soil organic carbon stock and stock changes are needed for Reducing emissions from deforestation and forest degradation
Reduction, reduced, or reduce may refer to:
Science and technology Chemistry
* Reduction (chemistry), part of a reduction-oxidation (redox) reaction in which atoms have their oxidation state changed.
** Organic redox reaction, a redox reacti ...
and GHG reporting under the UNFCCC.
The government of Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...
—together with the Food and Agriculture Organization of the United Nations
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
and the financial support of the government of Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
—have implemented a forest soil carbon monitoring program to estimate soil carbon stock, using both survey and modelling-based methods.
West Africa has experienced significant loss of forest that contains high levels of soil organic carbon. This is mostly due to expansion of small scale, non-mechanized agriculture using burning as a form of land clearance
See also
* Biochar
Biochar is the lightweight black residue, made of carbon and Ash (analytical chemistry),
ashes, remaining after the pyrolysis of biomass. Biochar is defined by the International Biochar Initiative as "the solid material obtained from the th ...
* Biosequestration
Biosequestration or biological sequestration is the capture and storage of the atmospheric greenhouse gas carbon dioxide by continual or enhanced biological processes.
This form of carbon sequestration occurs through increased rates of photosyn ...
* Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and Earth's atmosphere, atmosphere of the Earth. Carbon is the main component of biological compounds as well as ...
* Carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land ...
* Coarse woody debris
Coarse woody debris (CWD) or coarse woody habitat (CWH) refers to fallen dead trees and the remains of large branches on the ground in forests and in rivers or wetlands.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). C ...
* Mycorrhizal fungi and soil carbon storage
Soil carbon storage is an important function of terrestrial ecosystems. Soil contains more carbon than plants and the atmosphere combined. Understanding what maintains the soil carbon pool is important to understand the current distribution of ca ...
* Soil regeneration and climate change
References
{{DEFAULTSORT:Soil Carbon
Carbon
Land management
Carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
Soil science