Zygomycota

2018-05-08T01:33:35Z

Jasonkac:

[[File:Zygomycota.jpg|thumb|Sporangia of a Zygomycota fungus.]]
Zygomycota is a Phylum of the Kingdom Fungi. This phylum's name is derived from the method of sexual reproduction used by its members, which involve the creation of zygosporangia and zygospores. Asexual reproduction is possible, but more difficult, so the former is the preferred way to determine the classification of a Zygomycota. [1] There are approximately 900 known species that fall into this Phylum, which composes approximately one-hundredth of all true fungi. It is believed to be one of the earlier branches of fungi, thought to have diverged before plants colonized the lands 600 - 1,400 million years ago. [2]

== Identification ==
Most isolated specimens of Zygomycota do not have zygospores present (due to not currently undergoing sexual reproduction), so generally identification is based on sporangial morphology. Once the fungus matures and establishes itself on a medium, identification is most efficiently done, with emphasis on examination of sporangial morphology. Tease mounts with a drop of 95% alcohol is stated to be quite effective. [4] One particularly common example is Black Bread Mold (Rhizobus stolonifer), which belongs to Zygomycota. [6] Beyond their unique zygospores, Zygomycetes share many characteristics with their true fungi brethren, such as their chitin walls and hyphae, but their mycelia lack septa. [2]

== Reproduction ==
Members of Aygomycota reproduce both sexually and asexually, with differing life phases based on what type of reproduction is to occur. [5] For the former, gametangial fusion occurs and involves the formation of zygospores. The latter involves sporangia. [2] Besides the pros and cons that natively come with both sexual and asexual reproduction, for members of this phylum, zygospores appear better suited for preserving the fungus during times of hardship, while sporangia seem to be better suited for rapid establishment and colonization. [1] The ability to reproduce sexually is a trait that is uncommon among fungi, although it is not exclusive to Zygomycota. [6]

=== Zygospores and Sexual Reproduction ===
Sexual reproduction in Zygomycota is similar to the conjugation process that a microscopic organism such as a protozoan might use. To initiate this form of reproduction, certain hyphae called gametangia form a connection and exchange genetic material in nuclei in the center of the connected area. After it accumulates, septa are created to seal off the cell, meiosis creates chromosomes, and the cell where this has taken place grows thick, resistant walls that eventually disconnects. This site becomes known as a zygosporangium, and when the outer layers wear away (allowing the genetic material to be released if ready), it becomes a zygospore. [3] The gametangia used in this process have different "strains", plus and minus. These strains are morphologically similar but differ physiologically and biochemically. [5]

=== Asexual Reproduction ===
Asexual reproduction in Zygomycetes is centered on the production of sporangia, which themselves form at the ends of specialized hyphae called sporangiophores. Sporangiospores are formed by internal cleaving of cellular cytoplasm, and eventually the outer walls of sporangia will degrade, allowing spores with the same genetic material of the parent to disperse, aided by natural factors. [2]

== Impact on Other Organisms ==
This Phylum includes many parasitic members; insects in particular can be ravaged by Zygomycetes, but many larger animals (including humans) can become diseased by them, as well as smaller mesofauna, such as [[Nematodes]]. Some plants and fungi are also susceptible to infection by parasitic Zygomycetes. [1] However, some invertebrates have Zygomycetes in their digestive tracts, indicating that some members are mutualistic. For humans, arguably the main concern that Zygomycetes pose are their presence on spoiling foods, although some species can cause (potentially life-threatening) disease. Those most at risk for this are those with poor immune systems and broken skin. [6]

== References ==
[1] "Zygomycota". New Brunswick Museum. Accessed 2018-05-05. http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Zygomycota.html

[2] http://tolweb.org/Zygomycota

[3] http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Sporangia.html#Zygosporangia

[4] https://mycology.adelaide.edu.au/descriptions/zygomycetes/

[5] http://science.jrank.org/pages/2892/Fungi-Zygomycota-conjugating-fungi.html

[6] http://examples.yourdictionary.com/examples-of-zygomycetes.html

Zygomycota

2018-05-08T01:26:05Z

Jasonkac:

[[File:Zygomycota.jpg|thumb|Sporangia of a Zygomycota fungus.]]
Zygomycota is a Phylum of the Kingdom Fungi. This phylum's name is derived from the method of sexual reproduction used by its members, which involve the creation of zygosporangia and zygospores. Asexual reproduction is possible, but more difficult, so the former is the preferred way to determine the classification of a Zygomycota. [1] There are approximately 900 known species that fall into this Phylum, which composes approximately one-hundredth of all true fungi. It is believed to be one of the earlier branches of fungi, thought to have diverged before plants colonized the lands 600 - 1,400 million years ago. [2]

== Identification ==
Most isolated specimens of Zygomycota do not have zygospores present (due to not currently undergoing sexual reproduction), so generally identification is based on sporangial morphology. [4] Once the fungus matures and establishes itself on a medium, identification is most efficiently done. One particularly common example is Black Bread Mold (Rhizobus stolonifer), which belongs to Zygomycota. [6] Beyond their unique zygospores, Zygomycetes share many charachteristics with their true fungi brethren, such as their chitin walls and hyphae, but their mycelia lack septa. [2]

== Reproduction ==
Members of Aygomycota reproduce both sexually and asexually, with differing life phases based on what type of reproduction is to occur. [5] For the former, gametangial fusion occurs and involves the formation of zygospores. The latter involves sporangia. [2] Besides the pros and cons that natively come with both sexual and asexual reproduction, for members of this phylum, zygospores appear better suited for preserving the fungus during times of hardship, while sporangia seem to be better suited for rapid establishment and colonization. [1] The ability to reproduce sexually is a trait that is uncommon among fungi, although it is not exclusive to Zygomycota. [6]

=== Zygospores and Sexual Reproduction ===
Sexual reproduction in Zygomycota is similar to the conjugation process that a microscopic organism such as a protozoan might use. To initiate this form of reproduction, certain hyphae called gametangia form a connection and exchange genetic material in nuclei in the center of the connected area. After it accumulates, septa are created to seal off the cell, meiosis creates chromosomes, and the cell where this has taken place grows thick, resistant walls that eventually disconnects. This site becomes known as a zygosporangium, and when the outer layers wear away (allowing the genetic material to be released if ready), it becomes a zygospore. [3] The gametangia used in this process have different "strains", plus and minus. These strains are morphologically similar but differ physiologically and biochemically. [5]

=== Asexual Reproduction ===
Asexual reproduction in Zygomycetes is centered on the production of sporangia, which themselves form at the ends of specialized hyphae called sporangiophores. Sporangiospores are formed by internal cleaving of cellular cytoplasm, and eventually the outer walls of sporangia will degrade, allowing spores with the same genetic material of the parent to disperse, aided by natural factors. [2]

== Impact on Other Organisms ==
This Phylum includes many parasitic members; insects in particular can be ravaged by Zygomycetes, but many larger animals (including humans) can become diseased by them, as well as smaller mesofauna, such as [[Nematodes]]. Some plants and fungi are also susceptible to infection by parasitic Zygomycetes. [1] However, some invertebrates have Zygomycetes in their digestive tracts, indicating that some members are mutualistic. For humans, arguably the main concern that Zygomycetes pose are their presence on spoiling foods, although some species can cause (potentially life-threatening) disease. Those most at risk for this are those with poor immune systems and broken skin. [6]

== References ==
[1] "Zygomycota". New Brunswick Museum. Accessed 2018-05-05. http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Zygomycota.html

[2] http://tolweb.org/Zygomycota

[3] http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Sporangia.html#Zygosporangia

[4] https://mycology.adelaide.edu.au/descriptions/zygomycetes/

[5] http://science.jrank.org/pages/2892/Fungi-Zygomycota-conjugating-fungi.html

[6] http://examples.yourdictionary.com/examples-of-zygomycetes.html

Zygomycota

2018-05-08T00:18:39Z

Jasonkac:

[[File:Zygomycota.jpg|thumb|Sporangia of a Zygomycota fungus.]]
Zygomycota is a Phylum of the Kingdom Fungi. This phylum's name is derived from the method of sexual reproduction used by its members, which involve the creation of zygosporangia and zygospores. Asexual reproduction is possible, but more difficult, so the former is the preferred way to determine the classification of a Zygomycota. [1] There are approximately 900 known species that fall into this Phylum, which composes approximately one-hundredth of all true fungi. [2]

== Identification ==
Most isolated specimens of Zygomycota do not have zygospores present (due to not currently undergoing sexual reproduction), so generally identification is based on sporangial morphology. [4] Once the fungus matures and establishes itself on a medium, identification is most efficiently done. One particularly common example is Black Bread Mold (Rhizobus stolonifer), which belongs to Zygomycota. [6] Beyond their unique zygospores, Zygomycetes share many charachteristics with their true fungi brethren, such as their chitin walls and hyphae, but their mycelia lack septa. [2]

== Reproduction ==
Members of Aygomycota reproduce both sexually and asexually, with differing life phases based on what type of reproduction is to occur. [5] For the former, gametangial fusion occurs and involves the formation of zygospores. The latter involves sporangia. [2] Besides the pros and cons that natively come with both sexual and asexual reproduction, for members of this phylum, zygospores appear better suited for preserving the fungus during times of hardship, while sporangia seem to be better suited for rapid establishment and colonization. [1] The ability to reproduce sexually is a trait that is uncommon among fungi, although it is not exclusive to Zygomycota. [6]

=== Zygospores and Sexual Reproduction ===
Sexual reproduction in Zygomycota is similar to the conjugation process that a microscopic organism such as a protozoan might use. To initiate this form of reproduction, certain hyphae called gametangia form a connection and exchange genetic material in nuclei in the center of the connected area. After it accumulates, septa are created to seal off the cell, meiosis creates chromosomes, and the cell where this has taken place grows thick, resistant walls that eventually disconnects. This site becomes known as a zygosporangium, and when the outer layers wear away (allowing the genetic material to be released if ready), it becomes a zygospore. [3] The gametangia used in this process have different "strains", plus and minus. These strains are morphologically similar but differ physiologically and biochemically. [5]

== Impact on Other Organisms ==
This Phylum includes many parasitic members; insects in particular can be ravaged by Zygomycetes, but many larger animals (including humans) can become diseased by them. [1]

== References ==
[1] "Zygomycota". New Brunswick Museum. Accessed 2018-05-05. http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Zygomycota.html

[2] http://tolweb.org/Zygomycota

[3] http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Sporangia.html#Zygosporangia

[4] https://mycology.adelaide.edu.au/descriptions/zygomycetes/

[5] http://science.jrank.org/pages/2892/Fungi-Zygomycota-conjugating-fungi.html

[6] http://examples.yourdictionary.com/examples-of-zygomycetes.html

Zygomycota

2018-05-07T22:49:16Z

Jasonkac: /* References */

Zygomycota

2018-05-07T22:48:37Z

Jasonkac:

2018-04-20T01:02:28Z

2018-04-16T19:29:38Z

Jasonkac: A public domain image of an Eastern Mole; to be used with Jason Kaczmarczyk's "Moles" page.

A public domain image of an Eastern Mole; to be used with Jason Kaczmarczyk's "Moles" page.

Soil Horizons

2018-03-13T21:54:58Z

Jasonkac: Corrected a sentence in the first paragraph, with minor adjustments because of it.

[[File:Soil Horizons.gif|thumb|A basic diagram of the most common Master Horizons of a soil profile, with the E Horizon omitted]]
Soil Horizons are the distinct layers of a soil profile. They are divided into these layers, referred to as "Master Horizons" (from top to bottom): O Horizon, A Horizon, E Horizon, B Horizon, C Horizon, and R Horizon. There also exists an H Horizon, F Horizon, and an L Horizon, each of which revolve around organic material, somewhat similarly to the O Horizon, but with more specific qualities and generally more obscure. The number and composition of horizons in different soils has tremendous [[diversity]]; the most well-developed soils might have all of these layers, and the least-developed soils might only have an A and a D horizon.

= Main Master Horizons =

Master Horizons are the main layers of a soil profile, described below.

== O Horizon ==

The O Horizon is composed of organic material that has accumulated and been modified (physically and chemically) over time, typically from the remains of plant and animals [1]. This horizon is most easily observed in soils that are rarely, if ever, disturbed and with plenty of foliage and/or organisms nearby to contribute to its development, such as forests. In more barren locations such as grasslands, an O Horizon is rarer. [1] Due to the fact that its presence is determined by external factors (outside of the original parent materials that form soils), it is the only layer not dominated by mineral substances. This layer has three well-accepted subordinate horizons: Oi (slightly decomposed organic matter), Oe (moderately decomposed organic matter), and Oa (highly decomposed organic matter). [1] Microbial activity is high in this layer, utilizing the abundance of organic matter and decomposing it in ways that allow it to contribute to the soil profile.

== A Horizon ==
The A Horizon is a well-weathered and fertile layer dominated by mineral particles but still rich in organic matter, especially if covered by an O Horizon, which can leach decomposed organic matter into the A Horizon. This is a much thicker layer than the O Horizon, dominated by highly weathered mineral particles (the most highly weathered from the parent material of the soil), and typically darker and coarser than other Soil Horizons. (Elements pg. 53) The A Horizon is considered ''topsoil''. If this layer has properties of both an A and an E Horizon, it is considered an A Horizon if it is dominated by humidified organic matter. [4] Subterranean life (including microfauna, mesofauna, and macrofauna) tends to be the most abundant in this layer due to the rich, soft, and well-weathered environment of the soil.

== E Horizon ==
The E in "E Horizon" stands for eluviation, another word for leaching. This name is appropriate because, in this layer clay, iron, and aluminum oxides leach into the lower layers (mostly the B Horizon). [1] Like the O Horizon, this layer is not always present, but when it is, it's usually in forested areas and rarely in grasslands. Because of the loss of material through eluviation, it tends to be noticeably lighter than the layers above and below it. [1]

== B Horizon ==
The B Horizon is also known as the subsoil. B Horizons are often greatly composed of material illuviated (washed in from) layers above it, mostly clay, iron, aluminum oxides (deposited by elluviated water), and minerals that formed in the layer. [1]

== C Horizon ==
The C Horizon, also known as the substratum is unconsolidated material above bedrock. [2] It is insufficiently weathered to be considered soil, but still considered a layer of a soil profile. Subterranean life is far scarcer in this layer, and plant roots do not usually extend here, although it is usually soft enough for root penetration. [4] It is essentially a transitional layer from bedrock to the soil.

== R Horizon ==
This layer is simply bedrock with minimal to no weathering visible. It is composed of the parent material that would eventually be transformed into soil. Excavating this horizon generally requires specialized equipment, and roots are usually unable to take advantage of what cracks may be in this layer. [2]

== Other Master Horizons ==
These master horizons are dominated by plant-based organic matter in well-drained soils, occurring most commonly in forests. [5] These layers are generally more obscure than the previously mentioned Soil Horizons due to these specialized circumstances.

=== L Horizon ===
The L Horizon stands for "Litter Horizon" and is dominated by plant material with minimal to no visible decomposition, with plant elements easy to identify. [5]

=== F Horizon ===
The F Horizon stands for "Fermentation Horizon" and is composed of moderately decomposed plant material, but the plant origins are still distinguishable. [5]

=== H Horizon ===
The H Horizon stands for "Humic Horizon" and is composed of a material that is well humified and decomposed by water, and identifying plant material is difficult. [5]

= Transitional Horizons =
Soil Horizons do not always form distinct bands with unique and easily identified properties. Often Soil Horizons form Transitional Horizons, which have two forms. [3] The first is when a horizon has dominant properties of one Soil Horizon and subordinate properties of another; these Transitional Layers are designated by putting the dominant horizon properties letter first, followed by the subordinate horizon; an example would be a BC horizon, with properties more like a B Horizon but still demonstrating sufficient similarities to a C Horizon. [3] The second form of a Transitional Horizon is when the properties of both horizons are very comparable in representation; these have the letters separated with a "/", such as a B/C horizon, which is almost equally a B and a C Horizon. [3]

= Subordinate Horizons =
In order to more accurately describe the characteristics of the master horizons, lowercase letters from the Latin Alphabet are added. depending on the characteristics of the soil. Almost all letters are used, with the exception of ''l'' and ''u''. Instead, there are ''jj'' and ''ss'' distinctions. Subordinate horizon symbols include the following: [3]

a: Highly decomposed organic matter is present

b: The soil horizon has been buried

c: Concretions/Nodules of Fe, Al, Mn, or Ti cement is present

d: The soil is dense from natural or artificial means, and root access is restricted

e: Moderately decomposed organic matter is present

f: The soil is frozen

g: Strong gleying/mottling is present

h: The organic matter was illuviated

i: Slightly decomposed organic matter is present

j: Jarosite is present

jj: Cryoturbation / Frost churning is present

k: Carbonate buildup is present

m: Continuous cementation is present

n: Sodium buildup is present

o: Iron and Aluminum oxides buildup is present

p: The soil has been heavily disturbed, typically by tillage

q: Silica buildup is present

r: Bedrock is weathered or soft

s: Organic matter and Iron and Aluminum Oxides were illuviated (not to be confused with h and o, which are only organic matter and Iron and Aluminum Oxides, respectively)

ss: Slickensides are present

t: Buildup of silicate clays is present

v: Pilinthe is present

x: Fragipan is present

y: Buildup of gypsum is present

z: Buildup with salts more soluble than gypsum is present

= Factors Affecting the Formation of Soil Horizons =
Main articles: [[Pedogenesis]], [[Jenny Equation]]

Soil Horizon formation depends on many factors, most famously described by Hans Jenny's "fundamental equation": '''s = f (cl, o, r, p, t, …)'''

In this equation, soil is described as being a function of climate, organisms, relief/slope, parent material, time, and any other potential factors that he had not considered at the time of the formula's creation. Climate affects the rates of both physical and chemical weathering, Organisms affect the rate of soil formation and contribute organic matter to it, Relief affects the amount of water and erosion in a soil, Parent Material affects the initial properties of developing and mature soils, and time is required for these factors to go into effect and eventually form a soil and its Soil Horizons. [6] Other factors are almost certain to be contributing as well, but at a negligible or unknown scale.

= References =
[1] Brady, Nile C.; Weil, Ray R.. ''Elements of the Nature and Properties of Soil''. (Second Edition) Pearson Education, Inc. 2004. pg 53-55. Retrieved 2018-03-05.

[2] Turenne, Jim. ''Soil Horizons (a Basic Power Point Presentation)''. Retrieved 2018-03-06. http://nesoil.com/properties/horizons/

[3] ''Soils Glossary Appendix''. Soil Science Society of America. 2018. Retrieved 2018-03-06 https://www.soils.org/publications/glossary/appendix/

[4] Food and Agriculture Organization of the United Nations. ''World reference base for soil resources''. Rome 1998. Appendix 1: Soil Horizon Designations. Retrieved 2018-03-07. http://www.fao.org/docrep/W8594E/w8594e0g.htm

[5] Forest Floor. ''Soil Horizons''. Retrieved 2018-03-07. http://forestfloor.soilweb.ca/definitions/soil-horizons/

[6] Lamb, John A.; Rehm, George W.. ''Five factors of soil formation''. University of Minnesota. Retrieved 2018-03-07. https://www.extension.umn.edu/agriculture/soils/soil-properties/five-factors-soil-formation/

Flavonoids

2018-03-10T01:28:35Z

Jasonkac: Added that flavonoids are anti-inflammatory and can benefit the immune system.

Flavonoids are a group of phytonutrients found in all plants on the planet. Functions of these chemicals in plants include UV protection, defense against invasive pathogens, pigmentation, and signaling in symbiosis. This group of chemicals can be broken down further into subgroups based on the makeup of their chemical structures. In foods, flavonoids are full of natural antioxidants and can be found in a multitude of food types.

==Chemical structures==
[[File:Flav structures 2.0.png|thumb|Six subgroups of Flavonoids separated by chemical structure]]
All flavonoids consist of phenolic and pyrane rings and are generally insoluble. [2] Flavonoids differ in the arrangement of hydroxyl, methoxy, and glycosidic groups around a flavin backbone and from there form subgroups that include more specific chemicals. [1]

'''Flavones''' -Apigenin, Luteolin

'''Flavanones''' -Hesperetin, Naringenin, Eriodictyol

'''Flavonols''' -Quercetin, Kaempferol, Myricetin, Isorhamnetin

'''Flavan-3-ols''' -Catechins, Epicatechins, Epicatechin3-gallate, Epigallocatechin, Epigallocatechin 3-gallate, Gallocatechin, Theaflavin, Theaflavin 3-3’-digallate, Theaflavin 3’-gallate, Theaflavin 3-gallate, Thearubigins

'''Anthocyanidins''' -Cyanidin, Delphinidin, Malvidin, Pelargonidin, Peonidin, Petunidin

==Role in plant growth==
=== Within the Rhizosphere ===
Flavonoids aid in the interaction of plant roots with microorganisms in the surrounding area. [3] Roots can exude these chemicals through decomposing root caps and border cells. Once in the soil, flavonoids act as reducing agents and metal chelators towards metals. This increases the number of nutrients, particularly iron and phosphorous, available to the nearby plant roots.

Flavonoids are also key in the formation of nodules. Nodules are stores of fixed nitrogen created through a symbiotic relationship between plant roots and rhizobium bacteria. [6] Flavonoids improves transcription of nod genes by making access to RNA polymerase easier for the nodule to form. Conversely, nodule formation can be suppressed in order to maintain optimal conditions for the rate of nodule formation to remain unchanged.

Mycorrhizal fungi are also beneficiaries of flavonoids being present. Mycorrhizal fungi for hyphae in the soil which are then attracted to the exudates from the roots of a plant. The fungi then form ecto- or endomycorrhizal structures. Specifically, an isoflavonoid called coumestrol is heavily involved in the formation of hyphae. [3]

It is likely that flavonoids also play a role in the facilitation of arbuscular fungi invasions of the root. [3]

Flavonoid phytoalexins (antimicrobial and antioxidative substances) are activated in the case of an attempted breach of root tissue by an undesired outsider [3] These phytoalexins protect the root system from pathogens, undesirable bacteria, and even insects from interfering and harming their structures and/or growth space. These chemicals can be kept in dormant reserve for quick deployment if the need arises in the future. In terms of defense from pathogens, a flavonol called quercetin has been shown to repel attacks from ''E. coli'' by impeding ATPase activity (conversion of ATP to ADP resulting in a release of energy). [7]

Flavonoids have also been found to cause allelopathy, the release of chemicals that deter other plants from growing near the host plant. This can be a huge problem for agriculture in the case of an invasive plant species. This is exactly the case in some sub-Saharan African farm plots. The invasive weed ''Striga'' kills off any surrounding crop planted by farmers and can cause up to a 100% loss in crop yield. [4]

===Within the plant===
Studies have shown Flavonoids to play a role in photoprotection for plants. They exist in the highest concentrations within leaves exposed to high amounts of solar radiation. [8] Dihydroxy flavonoids dominate over other types and amounts/concentrations vary on a tissue to tissue or even a cell to cell basis. These dihydroxy flavonoids essentially replace existing hydroxycinnamates (which do not protect sensitive areas of the leaf from UV light very well) and form a stronger barrier. [8]

==Presence in foods==
[[File:-flav in fruits.jpg|thumb|Flavonoids are present in many foods including blueberries, cocoa beans, strawberries, and aloe vera plants]]
Flavonoids have been discovered to play a big role in the presence of antioxidants in common food sources. The five subgroups of flavonoids above exist as antioxidants within a multitude of common food items. [4]

Flavonols are found heavily in black tea and raw onions as well as in beer, coffee, and tomatoes. [4] Bee pollen has also found to contain flavonols. [5]

Dried and raw parsley contains more than 14,000 mg of flavones per gram of the plant. Flavones are also found in sweet, green, and hot chili peppers in addition to oranges and watermelons. [4]

Regular and decaffeinated black tea accounts for an overwhelming amount of flavan-3-ols consumed by humans, joined by peaches, pears, and bananas.

Flavanones are mainly found in oranges and grapefruit juice along with lemons and tangerines.

Anthocyanidins are commonly found in blueberries, strawberries, bananas, and cherries.

==Medicinal applications==

Flavonoids are proven to strengthen capillaries. HR, a flavonoid derived from rutin, is shown as effective in reducing CVI symptoms, like clearing leg swelling. They are anti-inflammatory and can benefit the immune system.

Anthocyanins, another type of flavonoid, significantly decreased the amount of visual field loss in patients with glaucoma.

Hydroxyethylrutosides flavonoids have been used to improve symptoms of Ménière's disease. [9]

==References==
[1] Heim, Kelly E, et al. “Flavonoid antioxidants: chemistry, metabolism and structure-Activity relationships.” The Journal of Nutritional Biochemistry, vol. 13, no. 10, 1 May 2002, pp. 572–584., doi:10.1016/s0955-2863(02)00208-5.

[2] Kumar, Shashank, and Abhay K. Pandey. “Chemistry and Biological Activities of Flavonoids: An Overview.” The Scientific World Journal, vol. 2013, 7 Oct. 2013, pp. 1–16., doi:10.1155/2013/162750.

[3] Hassan, S., and U. Mathesius. “The role of flavonoids in root-Rhizosphere signalling: opportunities and challenges for improving plant-Microbe interactions.” Journal of Experimental Botany, vol. 63, no. 9, Feb. 2012, pp. 3429–3444., doi:10.1093/jxb/err430.

[4] Kyle, J.A.M. et al. Flavonoids, chemistry, biochemistry and applications. In Flavonoids in Foods. Anderson, O.M. et al., Ed. CRC Press, Boca Raton, Fl. 2006

[5] Bhagwat, S., Haytowitz, D.B. Holden, J.M. (Ret.). 2014. USDA Database for the Flavonoid Content of Selected Foods, Release 3.1. U.S. Department of Agriculture, Agricultural Research Service. Nutrient Data Laboratory Home Page: http://www.ars.usda.gov/nutrientdata/flav

[6] Wang, Qi, et al. “Host-Secreted antimicrobial peptide enforces symbiotic selectivity in Medicago truncatula.” Proceedings of the National Academy of Sciences, vol. 114, no. 26, Dec. 2017, pp. 6854–6859., doi:10.1073/pnas.1700715114.

[7] Plaper A, Golob M, Hafner I, Oblak M, Solmajer T, Jerala R. 2003. Characterization of quercetin binding site on DNA gyrase. Biochemical and Biophysical Research Communications 306, 530–536.

[8] Agati, Giovanni, et al. “Functional roles of flavonoids in photoprotection: New evidence, lessons from the past.” Plant Physiology and Biochemistry, vol. 72, 18 Mar. 2013, pp. 35–45., doi:10.1016/j.plaphy.2013.03.014.

[9] de Sousa Araújo, Thiago Antônio, et al. "A new approach to study medicinal plants with tannins and flavonoids contents from the local knowledge." Journal of Ethnopharmacology 120.1 (2008): 72-80.

Soil Horizons

2018-03-09T21:19:22Z

Jasonkac:

[[File:Soil Horizons.gif|thumb|A basic diagram of the most common Master Horizons of a soil profile, with the E Horizon omitted]]
Soil Horizons are the distinct layers of a soil profile. They are divided into these layers, referred to as "Master Horizons" (from top to bottom): O Horizon, A Horizon, E Horizon, B Horizon, C Horizon, and R Horizon. There are also an H Horizon, F Horizon, and an L Horizon that revolve around organic material, similar to the O Horizon, but with more specific qualities and generally more obscure. The number and composition of horizons in different soils has tremendous [[diversity]]; the most well-developed soils might have all of these layers, and the least-developed soils might only have an A and a D horizon.

= Main Master Horizons =

Master Horizons are the main layers of a soil profile, described below.

== O Horizon ==

The O Horizon is composed of organic material that has accumulated and been modified (physically and chemically) over time, typically from the remains of plant and animals [1]. This horizon is most easily observed in soils that are rarely if ever disturbed and with plenty of foliage and/or organisms nearby to contribute to its development, such as forests; in more barren locations such as grasslands, an O Horizon is usually rarer. [1] Due to its presence being determined by external factors (outside of the original parent material that form soils), it is the only layer not dominated by mineral substances. This layer has three well-accepted subordinate horizons: Oi (slightly decomposed organic matter), Oe (moderately decomposed organic matter), and Oa (highly decomposed organic matter). [1] Microbial activity is high in this layer, utilizing the abundance of organic matter and decomposing it in ways that allow it to contribute to the soil profile.

== A Horizon ==
The A Horizon is a well-weathered and fertile layer dominated by mineral particles but still rich in organic matter, especially if covered by an O Horizon, which can leach decomposed organic matter into the A Horizon. This is a much thicker layer than the O Horizon, dominated by highly weathered mineral particles (the most highly weathered from the parent material of the soil), and typically darker and coarser than other Soil Horizons. (Elements pg. 53) The A Horizon is considered ''topsoil''. If this layer has properties of both an A and an E Horizon, it is considered an A Horizon if it is dominated by humidified organic matter. [4] Subterranean life (including microfauna, mesofauna, and macrofauna) tends to be the most abundant in this layer due to the rich, soft, and well-weathered environment of the soil.

== E Horizon ==
The E in "E Horizon" stands for ''eluviation'', another word for leaching. This name is appropriate because in this layer clay, iron, and aluminum oxides leach into the lower layers (mostly the B Horizon). [1] Like the O Horizon, this layer is not always present, but when it is, it's usually in forested areas and rarely in grasslands. Because of the loss of material through eluviation, it tends to be noticeably lighter than the layers above and below it. [1]

== B Horizon ==
The B Horizon is also known as the ''subsoil''. B Horizons are often greatly composed of material ''illuviated'' (washed in from) layers above it, mostly clay, iron, aluminum oxides (deposited by elluviated water), and minerals that formed in the layer. [1]

== C Horizon ==
The C Horizon, also known as the ''substratum'' is unconsolidated material above bedrock. [2] It is insufficiently weathered to be considered soil, but still considered a layer of a soil profile. Subterranean life is far scarcer in this layer, and plant roots do not usually extend here, although it is usually soft enough for root penetration. [4] It is essentially a transitional layer from bedrock to soil.

== R Horizon ==
This layer is simply bedrock with minimal to no weathering visible. It is composed of the parent material that would eventually be transformed into soil. Excavating this horizon generally requires specialized equipment, and roots are usually unable to take advantage of what cracks may be in this layer. [2]

== Other Master Horizons ==
These master horizons are dominated by plant-based organic matter in well-drained soils, occurring most commonly in forests. [5] These layers are generally more obscure than the previously mentioned Soil Horizons due to these specialized circumstances.

=== L Horizon ===
The L Horizon stands for "Litter Horizon" and is dominated by plant material with minimal to no visible decomposition, with plant elements easy to identify. [5]

=== F Horizon ===
The F Horizon stands for "Fermentation Horizon" and is composed of moderately decomposed plant material, but the plant origins are still distinguishable. [5]

=== H Horizon ===
The H Horizon stands for "Humic Horizon" and is composed of material that is well humified and decomposed by water, and identifying plant material is difficult. [5]

= Transitional Horizons =
Soil Horizons do not always form distinct bands with unique and easily identified properties. Often Soil Horizons form Transitional Horizons, which have two forms. [3] The first is when a horizon has dominant properties of one Soil Horizon and subordinate properties of another; these Transitional Layers are designated by putting the dominant horizon properties letter first, followed by the subordinate horizon; an example would be a BC horizon, with properties more like a B Horizon but still demonstrating sufficient similarities to a C Horizon. [3] The second form of a Transitional Horizon is when the properties of both horizons are very comparable in representation; these have the letters separated with a "/", such as a B/C horizon, which is almost equally a B and a C Horizon. [3]

= Subordinate Horizons =
In order to more accurately describe the characteristics of the master horizons, lowercase letters from the Latin Alphabet are added. depending on the characteristics of the soil. Almost all letters are used, with the exception of ''l'' and ''u''. Instead, there are ''jj'' and ''ss'' distinctions. Subordinate horizon symbols include the following: [3]

a: Highly decomposed organic matter is present

b: The soil horizon has been buried

c: Concretions/Nodules of Fe, Al, Mn, or Ti cement is present

d: The soil is dense from natural or artificial means, and root access is restricted

e: Moderately decomposed organic matter is present

f: The soil is frozen

g: Strong gleying/mottling is present

h: Organic matter was illuviated

i: Slightly decomposed organic matter is present

j: Jarosite is present

jj: Cryoturbation / Frost churning is present

k: Carbonate buildup is present

m: Continuous cementation is present

n: Sodium buildup is present

o: Iron and Aluminum oxides buildup is present

p: The soil has been heavily disturbed, typically by tillage

q: Silica buildup is present

r: Bedrock is weathered or soft

s: Organic matter and Iron and Aluminum Oxides were illuviated (not to be confused with h and o, which are only organic matter and Iron and Aluminum Oxides, respectively)

ss: Slickensides are present

t: Buildup of silicate clays is present

v: Pilinthe is present

x: Fragipan is present

y: Buildup of gypsum is present

z: Buildup with salts more soluble than gypsum is present

= Factors Affecting the Formation of Soil Horizons =
Main articles: [[Pedogenesis]], [[Jenny Equation]]

Soil Horizon formation depends on many factors, most famously described by Hans Jenny's "fundamental equation": '''s = f (cl, o, r, p, t, …)'''

In this equation, soil is described as being a function of climate, organisms, relief/slope, parent material, time, and any other potential factors that he had not considered at the time of the formula's creation. Climate affects the rates of both physical and chemical weathering, Organisms affect the rate of soil formation and contribute organic matter to it, Relief affects the amount of water and erosion in a soil, Parent Material affects the initial properties of developing and mature soils, and time is required for these factors to go into effect and eventually form a soil and its Soil Horizons. [6] Other factors are almost certain to be contributing as well, but at a negligible or unknown scale.

= References =
[1] Brady, Nile C.; Weil, Ray R.. ''Elements of the Nature and Properties of Soil''. (Second Edition) Pearson Education, Inc. 2004. pg 53-55. Retrieved 2018-03-05.

[2] Turenne, Jim. ''Soil Horizons (a Basic Power Point Presentation)''. Retrieved 2018-03-06. http://nesoil.com/properties/horizons/

[3] ''Soils Glossary Appendix''. Soil Science Society of America. 2018. Retrieved 2018-03-06 https://www.soils.org/publications/glossary/appendix/

[4] Food and Agriculture Organization of the United Nations. ''World reference base for soil resources''. Rome 1998. Appendix 1: Soil Horizon Designations. Retrieved 2018-03-07. http://www.fao.org/docrep/W8594E/w8594e0g.htm

[5] Forest Floor. ''Soil Horizons''. Retrieved 2018-03-07. http://forestfloor.soilweb.ca/definitions/soil-horizons/

[6] Lamb, John A.; Rehm, George W.. ''Five factors of soil formation''. University of Minnesota. Retrieved 2018-03-07. https://www.extension.umn.edu/agriculture/soils/soil-properties/five-factors-soil-formation/

Pedogenesis

2018-03-09T20:47:14Z

Jasonkac: Corrected "late 18th century (1880s)" to "late 19th century (1880s)", and added a comma in the "Other Possible Factors" subsection.

== Pedogenesis ==
[[File:Soil.jpg|thumb|Soil Profile detailing the differences between horizon depths]]
Pedogenesis is the process of soil formation. Soil has many biological, chemical, and physical factors that are variable, and constantly subject to change. Its nature, profile build-up and specific properties are the direct result of several pedogenic processes. In the late 19th century (1880s), Russian scientist Vasily Dokuchaev perceived soil as an “independent natural body” regarded as a function of local maternal rock variety, age of the land (time since it became surface land), climate, and vegetation [3]. His ideas were expanded in the next century by scientist Hans Jenny, who in the 1940s, established that the development of soil is influenced by five interrelated factors: climate, organisms, relief (topography), parent material, and time [2]. In 1941, Jenny detailed his ideas and observations in his book, “Factors of Soil Formation: A System of Quantitative Pedology”, where he coined the term pedogenesis, and outlined an equation that would account for soil formation [7]. This equation also known as the State Factor Model is summarized as:
s = f(cl, o, r, p, t, ...).

== Origin (Founders) ==
The origin of pedogenesis as a form of study dates back to Vasily Dokuchaev. He believed that pedogenesis was principally [[File:Hans.jpg|thumb|Jenny's literature detailing pedogenesis (1941)]] controlled by vegetation and climate [2]. This was based on observations that alike soils developed in spatially separate areas when their vegetation and climate were similar. Konstantin Glinka, a student of Dokuchaev, went on to express soil as “not only a natural body with definite properties, but also its geographical position and surroundings, I.e. climate, vegetation, and animal life” [3]. Hans Jenny’s interpretation, which was based on Dokuchaev and those that came before him, provided a detailed definition of both soil and the "larger system," as well as a method to quantitatively and numerically link soil and larger system properties to state factors [3]. This “larger system” would be “composed of the upper part of the lithosphere, the lower part of the atmosphere, and a considerable part of the biosphere.”

== Pedogenesis Factors ==
Hans Jenny formulated the pedogenesis concept into the “fundamental equation of soil-forming factors”, also known as the [[Jenny Equation]]:

'''s = f (cl, o, r, p, t, …)'''.

This equation states that soil formation (s) is a function (f) of climate (cl), organisms (o), relief (r), parent material (p), and time (t). Jenny also left an ellipses (…) in the equation, for other possible considerations that he did not ponder at the time [7].
[[File:Pedogenesis_factors.jpg|thumb|Pedogegenesis Factors]]

'''Climate (cl):'''

The climate factor of soil genesis is the climate (I.e. temperature, precipitation, and humidity) of the ecosystem [3]. Temperature and moisture are two climatic components that are very influential in pedogenesis [2]. The production of mineral particles caused by weathering is directly influenced by temperature. Bedrock weathering rates typically increase with higher temperatures. Moisture levels in soils are mainly regulated by water additions through precipitation minus the losses due to evapotranspiration [2]. Moisture availability also has impacts on the decomposition of organic matter and the soil pH.

'''Organisms (o):'''

The organism factor deals with the potential biota of the system [3]. It is the microbial, plant, and animal gene flux that cycles through the system from its surroundings [3]. Organic components dealing with pedogenesis include organic matter accumulation, profile mixing, and biogeochemical nutrient cycling [2]. Litter and decomposing processes adds to the top layer of soil and increases nutrients influencing fertility and structure. Vegetation also helps in binding soil and protecting the surface from erosion from water and wind.

'''Relief (r):'''

The relief or topography deals with the subvariables that correspond to the physical make up of an ecosystem at the beginning of its development, or the start of an observation period [3]. The site’s position on a hillslope, the range of its slope, the proximity of the site to the water table are examples of the subvariables. Relief typically moderates the formation of soil on a regional or local scale, and pedogenesis is directly related to microclimate and drainage influenced by the topography [2]. The development of soil horizons are caused by illuviation and eluviation drainage processes [2]. Microclimate would be influenced by which side of a hill is warmer than a side facing another direction. This results in soils of different areas having differences in terms of texture, depth, biota, and profile development [2].

'''Parent Material (p):'''

The parent material factor is defined as the initial state of the rock, sediment, or minerals of an ecosystem from which the soils develop [3]. Weathering of bedrock and transported sediments from erosive means can make up this factor. For a habitat that has been clear-cut or burned down, the parent material would be the present soil at which the new flora and fauna begin to grow over[3]. Parent material influences are generally related to soil chemistry and texture, and nutrient cycling.

'''Time (t):'''

Time is the period since the ecosystem began forming, or since the assemblage of state factors changed. It is the temporal consequences of all the summed up state factors. Time at 0 (t=0), the starting point could be after a depositional event, or a major disturbance or configuration of all the pedogenesis factors [3]. Through time, soils receive positive and negative feedback in an attempt to reach equilibrium [2]. Steady state is reached over time when a soil reaches maturity.

'''Other Possible Factors (...):'''

There could be additional state factors dealing with soil formation. One could say that humans could be an element to the equation [3]. Based on our extreme influence and control over ecosystems, soil formation could be swayed by human direct or indirect involvement. This factor can fall under the organism (o) state factor, however. A subdivision of the human factor could be cultural inheritance (c) [3]. This would be the assemblage of a population in an ecosystem at t=0, based on culture (technologies, ideas, and philosophies of individuals) [3]. This would have a substantial effect on ecosystem development, as well as soil formation and alteration.

== References ==
[1] Veldkamp, Antonie. “PEDOGENESIS AND SOIL FORMING FACTORS .” LAND USE, LAND COVER AND SOIL SCIENCES – Vol. VI, [http://www.eolss.net/Sample-Chapters/C12/E1-05-07-02.pdf www.eolss.net/Sample-Chapters/C12/E1-05-07-02.pdf].

[2] “CHAPTER 10: Introduction to the Lithosphere (u). Soil Pedogenesis.” Physical Geography, [http://www.physicalgeography.net/fundamentals/10u.html www.physicalgeography.net/fundamentals/10u.html].

[3] Amundson, Ronald, and Hans Jenny. “On a State Factor Model of Ecosystems.” BioScience, 1 Sept. 1997, [http://www.jstor.org/stable/1313122?origin=JSTOR-pdf&seq=1#page_scan_tab_contents www.jstor.org/stable/1313122?origin=JSTOR-pdf&seq=1#page_scan_tab_contents].

[4] “Plate Tectonics.” Soils, Weathering, and Nutrients, 16 Sept. 2013, [http://globalchange.umich.edu/globalchange1/current/lectures/soils/soils.html globalchange.umich.edu/globalchange1/current/lectures/soils/soils.html].

[5] Historical Overview of Soils and the Fitnes of the Soil Environment.” Fundamentals of Soil Ecology, by David C Coleman, 2nd ed., 2004.

[6] “How Soils Form | Environment, Land and Water.” Environment, Land and Water | Queensland Government, Queensland, 8 Oct. 2013, [http://www.qld.gov.au/environment/land/soil/soil-explained/forms www.qld.gov.au/environment/land/soil/soil-explained/forms].

[7] Henshue, Nicholas. “Introduction to Soil Ecology.” Soil Ecology, Week 1, pp. 1–33., [http://ublearns.buffalo.edu/bbcswebdav/pid-4467366-dt-content-rid-17751926_1/courses/2181_23766/intro%201.pdf ublearns.buffalo.edu/bbcswebdav/pid-4467366-dt-content-rid-17751926_1/courses/2181_23766/intro%201.pdf].

Pedogenesis

2018-03-09T20:39:24Z

Jasonkac: Added an internal link to the Jenny Equation page and a few extremely minor edits. (Jason Kaczmarczyk)

== Pedogenesis ==
[[File:Soil.jpg|thumb|Soil Profile detailing the differences between horizon depths]]
Pedogenesis is the process of soil formation. Soil has many biological, chemical, and physical factors that are variable, and constantly subject to change. Its nature, profile build-up and specific properties are the direct result of several pedogenic processes. In the late 18th century (1880s), Russian scientist Vasily Dokuchaev perceived soil as an “independent natural body” regarded as a function of local maternal rock variety, age of the land (time since it became surface land), climate, and vegetation [3]. His ideas were expanded in the next century by scientist Hans Jenny, who in the 1940s, established that the development of soil is influenced by five interrelated factors: climate, organisms, relief (topography), parent material, and time [2]. In 1941, Jenny detailed his ideas and observations in his book, “Factors of Soil Formation: A System of Quantitative Pedology”, where he coined the term pedogenesis, and outlined an equation that would account for soil formation [7]. This equation also known as the State Factor Model is summarized as:
s = f(cl, o, r, p, t, ...).

== Origin (Founders) ==
The origin of pedogenesis as a form of study dates back to Vasily Dokuchaev. He believed that pedogenesis was principally [[File:Hans.jpg|thumb|Jenny's literature detailing pedogenesis (1941)]] controlled by vegetation and climate [2]. This was based on observations that alike soils developed in spatially separate areas when their vegetation and climate were similar. Konstantin Glinka, a student of Dokuchaev, went on to express soil as “not only a natural body with definite properties, but also its geographical position and surroundings, I.e. climate, vegetation, and animal life” [3]. Hans Jenny’s interpretation, which was based on Dokuchaev and those that came before him, provided a detailed definition of both soil and the "larger system," as well as a method to quantitatively and numerically link soil and larger system properties to state factors [3]. This “larger system” would be “composed of the upper part of the lithosphere, the lower part of the atmosphere, and a considerable part of the biosphere.”

== Pedogenesis Factors ==
Hans Jenny formulated the pedogenesis concept into the “fundamental equation of soil-forming factors”, also known as the [[Jenny Equation]]:

'''s = f (cl, o, r, p, t, …)'''.

This equation states that soil formation (s) is a function (f) of climate (cl), organisms (o), relief (r), parent material (p), and time (t). Jenny also left an ellipses (…) in the equation, for other possible considerations that he did not ponder at the time [7].
[[File:Pedogenesis_factors.jpg|thumb|Pedogegenesis Factors]]

'''Climate (cl):'''

The climate factor of soil genesis is the climate (I.e. temperature, precipitation, and humidity) of the ecosystem [3]. Temperature and moisture are two climatic components that are very influential in pedogenesis [2]. The production of mineral particles caused by weathering is directly influenced by temperature. Bedrock weathering rates typically increase with higher temperatures. Moisture levels in soils are mainly regulated by water additions through precipitation minus the losses due to evapotranspiration [2]. Moisture availability also has impacts on the decomposition of organic matter and the soil pH.

'''Organisms (o):'''

The organism factor deals with the potential biota of the system [3]. It is the microbial, plant, and animal gene flux that cycles through the system from its surroundings [3]. Organic components dealing with pedogenesis include organic matter accumulation, profile mixing, and biogeochemical nutrient cycling [2]. Litter and decomposing processes adds to the top layer of soil and increases nutrients influencing fertility and structure. Vegetation also helps in binding soil and protecting the surface from erosion from water and wind.

'''Relief (r):'''

The relief or topography deals with the subvariables that correspond to the physical make up of an ecosystem at the beginning of its development, or the start of an observation period [3]. The site’s position on a hillslope, the range of its slope, the proximity of the site to the water table are examples of the subvariables. Relief typically moderates the formation of soil on a regional or local scale, and pedogenesis is directly related to microclimate and drainage influenced by the topography [2]. The development of soil horizons are caused by illuviation and eluviation drainage processes [2]. Microclimate would be influenced by which side of a hill is warmer than a side facing another direction. This results in soils of different areas having differences in terms of texture, depth, biota, and profile development [2].

'''Parent Material (p):'''

The parent material factor is defined as the initial state of the rock, sediment, or minerals of an ecosystem from which the soils develop [3]. Weathering of bedrock and transported sediments from erosive means can make up this factor. For a habitat that has been clear-cut or burned down, the parent material would be the present soil at which the new flora and fauna begin to grow over[3]. Parent material influences are generally related to soil chemistry and texture, and nutrient cycling.

'''Time (t):'''

Time is the period since the ecosystem began forming, or since the assemblage of state factors changed. It is the temporal consequences of all the summed up state factors. Time at 0 (t=0), the starting point could be after a depositional event, or a major disturbance or configuration of all the pedogenesis factors [3]. Through time, soils receive positive and negative feedback in an attempt to reach equilibrium [2]. Steady state is reached over time when a soil reaches maturity.

'''Other Possible Factors (...):'''

There could be additional state factors dealing with soil formation. One could say that humans could be an element to the equation [3]. Based on our extreme influence and control over ecosystems, soil formation could be swayed by human direct or indirect involvement. This factor can fall under the organism (o) state factor however. A subdivision of the human factor could be cultural inheritance (c) [3]. This would be the assemblage of a population in an ecosystem at t=0, based on culture (technologies, ideas, and philosophies of individuals) [3]. This would have a substantial effect on ecosystem development, as well as soil formation and alteration.

== References ==
[1] Veldkamp, Antonie. “PEDOGENESIS AND SOIL FORMING FACTORS .” LAND USE, LAND COVER AND SOIL SCIENCES – Vol. VI, [http://www.eolss.net/Sample-Chapters/C12/E1-05-07-02.pdf www.eolss.net/Sample-Chapters/C12/E1-05-07-02.pdf].

[2] “CHAPTER 10: Introduction to the Lithosphere (u). Soil Pedogenesis.” Physical Geography, [http://www.physicalgeography.net/fundamentals/10u.html www.physicalgeography.net/fundamentals/10u.html].

[3] Amundson, Ronald, and Hans Jenny. “On a State Factor Model of Ecosystems.” BioScience, 1 Sept. 1997, [http://www.jstor.org/stable/1313122?origin=JSTOR-pdf&seq=1#page_scan_tab_contents www.jstor.org/stable/1313122?origin=JSTOR-pdf&seq=1#page_scan_tab_contents].

[4] “Plate Tectonics.” Soils, Weathering, and Nutrients, 16 Sept. 2013, [http://globalchange.umich.edu/globalchange1/current/lectures/soils/soils.html globalchange.umich.edu/globalchange1/current/lectures/soils/soils.html].

[5] Historical Overview of Soils and the Fitnes of the Soil Environment.” Fundamentals of Soil Ecology, by David C Coleman, 2nd ed., 2004.

[6] “How Soils Form | Environment, Land and Water.” Environment, Land and Water | Queensland Government, Queensland, 8 Oct. 2013, [http://www.qld.gov.au/environment/land/soil/soil-explained/forms www.qld.gov.au/environment/land/soil/soil-explained/forms].

[7] Henshue, Nicholas. “Introduction to Soil Ecology.” Soil Ecology, Week 1, pp. 1–33., [http://ublearns.buffalo.edu/bbcswebdav/pid-4467366-dt-content-rid-17751926_1/courses/2181_23766/intro%201.pdf ublearns.buffalo.edu/bbcswebdav/pid-4467366-dt-content-rid-17751926_1/courses/2181_23766/intro%201.pdf].

Jenny Equation

2018-03-09T20:16:15Z

Jasonkac: Minor adjustment to the paragraph layout and for concise language. A redundant sentence was also removed. (Jason Kaczmarczyk)

== Origins ==

The Jenny Equation was created by Hans Jenny to explain the soil formation process. It was first internationally recognized when Hans Jenny published his book “Factors of Soil Formation” in 1941. The Jenny Equation is a formula used to help determine the properties of the soil such as fertility and mineral composition, as well as the organisms living within the soil and the chemical reactions that will occur around plant roots and the other organisms.

== Hans Jenny ==

[[File:Hans Jenny.jpg|frame|A photograph of Hans Jenny]]

Hans Jenny was born in Switzerland in 1899. His college career started with the Swiss Federal Institute of Technology (Zurich) where he received a bachelor in agriculture in 1922. He later received degrees in chemistry and ion exchange reactions by 1927, also from Zurich. In 1936 he joined The University of California, Berkeley as a member of the faculty. His intensive education helped him formulate the Jenny Equation, which is S = f(cl, o, r, p, t, …). In this equation the “S” represents soil formation, "cl" is climate, "o" is organisms in the soil, "r" is relief such as the topography, “p” is the parent material, “t” is the time that takes place. He left the “…” in case something new was discovered or needed to be added later.

== Uses of Jenny Equation ==

The Jenny Equation helps determine the physical properties of soil based on several independent factors. These factors are known as the pedogenic processes, which in this equation are climate, organisms, topography, parent material, time, and any other factors that may apply. The Jenny equation is used to help design soil maps, which demonstrate a soil's contents and helps determine what it is useful for.
[[File:Soil factors 1.jpeg|thumb]]

== Climate ==
[[File:Soi eroision 2.gif|thumb]]

Two of the most influential factors of climate are temperature and moisture. Temperature has a direct effect on the rate that chemical reactions can occur in the soil. The higher the temperature, the quicker the reactions will happen within the soil. Moisture also affects the rates of chemical reactions that can happen in the soil. Like with temperature, higher moisture levels increase the rates of chemical reactions. This will allow plants to grow faster, as well as allowing the bacteria and fungus to be more active. Decomposers are more efficient when the temperature and moisture levels are high. Rainfall also has the impact of weathering and erosion. This helps to break down the larger rocks and other soil particles into smaller pieces.

== Organisms ==
Main article: [[Organisms]]

The organisms in the soil also influence the soils processes and functions. The vegetation and animals have a significant role. Plants roots help to break up the soil by creating more surface area for water to seep into. This allows chemical reactions to occur here as plants excrete chemicals that help these chemical reactions to take place. These chemicals also attract bacteria and fungi, which allow them to help speed up the roots' ability to uptake nutrients as well as fend off harmful chemicals and organisms. Bacteria and fungi also can multiply and decompose detritus more easily. Dead organisms in the soil allow for more nutrients to be available for plant uptake after decomposition begins, which also enhances soil fertility.

== Topography ==
[[File:Soil horizons 3.png|thumb]]

The next factor in the equation is topography. Topography is the slope of the land, whether there is a hill, valley, flat plain, or other meaningful change in elevation. The topography of the land is a significant factor for the moisture content of the soil. For example, a hill will have a lower moisture content because of increased runoff, which limits the amount of infiltration by water into the soil. A valley will have a very high moisture content because the amount of water that can go into the soil is higher, as the water will drain into this area and accumulate, and have more time to infiltrate. A plain will have a medium amount of moisture in the soil. The slope also effects the type of vegetation that can grow as there will be more moisture in some areas than others. Slopes are also more prone to soil erosion.

== Parent Material ==

The parent material of the soil is determined from what type of rock it is derived from. Igneous, metamorphic, or sedimentary rock break down and create different types of soil, whether it is sandy, silt or clay dominated soil. The breaking down of the soil increases the surface area which allows more reactions to happen, enhances the soil's water retention, and allows more organisms to be able to live within it. The parent material will also determine the mineral composition of the soil. For example, if a rock rich in phosphorous breaks down due to weathering, the soil that it creates will have a higher content of phosphorus. The minerals in the soil will affect the types of organisms and plants that can thrive in the soil. If a soil is darker colored, it is from a volcanic eruption; these are metamorphic rocks. Lighter soils are formed from igneous rocks.

== Time ==

Time is the next variable in the equation. The amount of time directly affects the weathering rates. As the time increases the more weathering can occur, which allows the parent material to break down further and create different minerals and smaller soil particles. Time also affects the amount of growth a plant will have and its interactivity with the soil, through roots and the chemicals released by them, as well as the uptake of nutrients.

== Additional Factors ==

Hans Jenny also left room in the equation for any other factors that he could not think of, or had not yet been discovered. However, nothing has been added to Hans Jenny’s equation since it was originally written in 1941, as no new factors that influence the way soils react with their environments have yet been found.

== References ==

http://texts.cdlib.org/view?docId=hb7c6007sj;NAAN=13030&doc.view=frames&chunk.id=div00028&toc.depth=1&toc.id=&brand=calisphere

http://www.physicalgeography.net/fundamentals/10u.html

http://www.innspub.net/wp-content/uploads/2013/12/JBES-Vol3No12-p125-134.pdf

https://www.researchgate.net/publication/280237646_Predicting_soil_map_using_Jenny_equation

http://forces.si.edu/soils/02_01_04.html

https://www.revolvy.com/main/index.php?s=Clorpt