Soil Ecology Wiki - User contributions [en]

Diversity

2018-05-11T14:00:02Z

Serenani: /* Soil Biodiversity */

Diversity is defined as the state of being diverse, having a variety. Diversity is apparent in many aspects of [[soil]]. Two examples of soil diversity are the different soil orders and the soil biodiversity.

== Soil Orders in the United States ==

[[File:4-Figure1-1.png|500px|thumb|left| Soil orders in the United States]]

The United States exhibits a vast array of soil orders, as shown in the image to the left. The soil orders included in this map are: Alfisols, Andisols, Aridsols, Entisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, and Vertisols.

Alfisols have a base saturation over 35 percent and have subsoil horizons enriched with clay. This type of soil is typically found under forest and savanna vegetation. Alfisoils are generally fertile, with production levels similar to that of Mollisols and Ultisols. They are typically abundant in nutrient cations of Ca, Mg, K, and Na. They make up about 10 percent of the world's ice free land areas.

----

Andisols form in or near areas of recent volcanism and are made from volcanic parent materials unique chemical properties. They have limited geographic distribution, but have potentially high productivity due to their tendency to accumulate organic material, and are easily cultivated. They lack development of [[soil horizons]] and are not typically extensively weathered. They make up about 1 percent of the worlds ice-free land areas.

----

Aridsols are soils in arid climates that have visible chemical/weathering alteration. They often have accumulation of CaCo3(lime) and NaCl(salt), but normally have low amounts of organic matter content. Aridsols normally are water deficient, and do not allow for the growth of crops without irrigation. Without irrigation and fertilization, the productivity of Aridsols are generally low. They make up 12 percent of the world's ice free land areas.

----

Entisols lack development of [[Soil Horizons]]. This type of soil can be formed from a wide variety of parent material, making its properties and productivity varied. These soils are often found in dry or cool environments, commonly being found with Aridsols. Very productive Entisols can be found on floodplains, while low productivity in this soil can be found on steep slopes or sandy areas. They make up 16 percent of the world's ice free land areas.

----

Histosols are soils that are mainly composed of organic materials. The organic matter accumulates because the soil is usually very saturated, which creates anerobic conditions that cause the accumulation of organic matter to be faster than decompostion. These soils are typically found in wetland environments and make up 1 percent of the world's ice free land areas.

----

Inceptisols are freely draining soils soils that exhibit beginning stages of soil horizon development. This type of soil is typically found in mountain areas and have a varied productivity. They make up 10 percent of the world's ice free land areas.

----

Mollisols typically develop in grasslands and have a thick organic-rich A horizon. This type of soil is extremely productive due to its saturation of the cations Ca2+, Mg2+, Na+, and K+. All of those cations are essential plant nutrients. This type of soil makes up 7 percent of the worlds ice free land areas.

----

Oxisols are typically found in the tropics and are highly chemically altered. These soils are naturally low in fertility and high in acidity. They are leeched and require fertilizers and an input of nutrients in order to be productive for agriculture. This type of soils makes up 8 percent of the world's ice free land area.

----

Spodosols are coarse-textured soils with high leeching potential. They are typically located in northern latitude forests, forming from sandy parent material. The Fe and Al compounds in this soil have a strong geochemical separation. This soil is naturally low in fertility and high in acidity, like Oxisols. This soil requires nutrient input and fertilizers in order to be productive for agriculture. This type of soil makes up 4 percent of the world's ice free land area.

----

Ultisols occur in warm, humid climates and have clay-enriched B horizons. They form from weathered parent material in older regions. Ultisols are low in natural fertility and high in acidity, so they require nutrient input and fertilizer to be productive for agriculture. They make up 8 percent of the world's ice free land area.

----

Vertisols exhibit a shrink-swell behavior with changing water content due to their high concentration of silicate clay. When the soil shrinks it forms deep cracks, which allow material to fall into it. This material will then be incorporated into the soil when the soil swells again. These typically form in warm climates in limestone, basalt, or topographic depressions. Vertisols make up 2 percent of the world's ice free land area.

== Soil Biodiversity ==

Soil biodiversity refer to the diversity of living [[organisms]] in the soil. The most biologically diverse part of the earth is the soil. The soil has a vast biological web of interactions between [[microorganisms]], plants, and [[macroorganisms]]. [[Bacteria]], [[fungi]], [[annelids]], spiders, [[collembola]], [[tardigrades]], [[springtail]], ants, and countless other organisms make up the diversity of the soil. These organisms are important to the flow of nutrients through the soil, which helps productivity. They help plants that grow on top of the soil by providing services like: retaining nutrients, preventing nutrient leeching, decomposing dead matter, returning nutrients to their mineral form, and improving water filtration by forming soil aggregates. The soil may not appear to be alive because many of the organisms are very small, but that does not mean it is not diverse in life. A handful of soil can contain a billion different [[organisms]].

== Citations ==

*Amundson, R., Guo, Y. & Gong, P. Ecosystems (2003) 6: 470.
*Bailey, Robert G. Description of the ecoregions of the United States. U.S. Dept. of Agriculture, Forest Service, 1995
*Guo, Yinyan, et al. “Pedodiversity in the United States of America.” Geoderma, vol. 117, no. 1-2, 2003, pp. 99–115.
*Brussaard, Lijbert. “Biodiversity and Ecosystem Functioning in Soil.” Ambio, vol. 26, no. 8, 1997, pp. 563–570.
*Wardle, D. A. (2006), The influence of biotic interactions on soil biodiversity. Ecology Letters, 9: 870–886.
*Diana H. Wall, John C. Moore; Interactions Underground: Soil biodiversity, mutualism, and ecosystem processes, BioScience, Volume 49, Issue 2, 1 February 1999, Pages 109–117

Diversity

2018-05-11T13:59:32Z

Serenani: /* Soil Biodiversity */

Diversity is defined as the state of being diverse, having a variety. Diversity is apparent in many aspects of [[soil]]. Two examples of soil diversity are the different soil orders and the soil biodiversity.

== Soil Orders in the United States ==

[[File:4-Figure1-1.png|500px|thumb|left| Soil orders in the United States]]

The United States exhibits a vast array of soil orders, as shown in the image to the left. The soil orders included in this map are: Alfisols, Andisols, Aridsols, Entisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, and Vertisols.

Alfisols have a base saturation over 35 percent and have subsoil horizons enriched with clay. This type of soil is typically found under forest and savanna vegetation. Alfisoils are generally fertile, with production levels similar to that of Mollisols and Ultisols. They are typically abundant in nutrient cations of Ca, Mg, K, and Na. They make up about 10 percent of the world's ice free land areas.

----

Andisols form in or near areas of recent volcanism and are made from volcanic parent materials unique chemical properties. They have limited geographic distribution, but have potentially high productivity due to their tendency to accumulate organic material, and are easily cultivated. They lack development of [[soil horizons]] and are not typically extensively weathered. They make up about 1 percent of the worlds ice-free land areas.

----

Aridsols are soils in arid climates that have visible chemical/weathering alteration. They often have accumulation of CaCo3(lime) and NaCl(salt), but normally have low amounts of organic matter content. Aridsols normally are water deficient, and do not allow for the growth of crops without irrigation. Without irrigation and fertilization, the productivity of Aridsols are generally low. They make up 12 percent of the world's ice free land areas.

----

Entisols lack development of [[Soil Horizons]]. This type of soil can be formed from a wide variety of parent material, making its properties and productivity varied. These soils are often found in dry or cool environments, commonly being found with Aridsols. Very productive Entisols can be found on floodplains, while low productivity in this soil can be found on steep slopes or sandy areas. They make up 16 percent of the world's ice free land areas.

----

Histosols are soils that are mainly composed of organic materials. The organic matter accumulates because the soil is usually very saturated, which creates anerobic conditions that cause the accumulation of organic matter to be faster than decompostion. These soils are typically found in wetland environments and make up 1 percent of the world's ice free land areas.

----

Inceptisols are freely draining soils soils that exhibit beginning stages of soil horizon development. This type of soil is typically found in mountain areas and have a varied productivity. They make up 10 percent of the world's ice free land areas.

----

Mollisols typically develop in grasslands and have a thick organic-rich A horizon. This type of soil is extremely productive due to its saturation of the cations Ca2+, Mg2+, Na+, and K+. All of those cations are essential plant nutrients. This type of soil makes up 7 percent of the worlds ice free land areas.

----

Oxisols are typically found in the tropics and are highly chemically altered. These soils are naturally low in fertility and high in acidity. They are leeched and require fertilizers and an input of nutrients in order to be productive for agriculture. This type of soils makes up 8 percent of the world's ice free land area.

----

Spodosols are coarse-textured soils with high leeching potential. They are typically located in northern latitude forests, forming from sandy parent material. The Fe and Al compounds in this soil have a strong geochemical separation. This soil is naturally low in fertility and high in acidity, like Oxisols. This soil requires nutrient input and fertilizers in order to be productive for agriculture. This type of soil makes up 4 percent of the world's ice free land area.

----

Ultisols occur in warm, humid climates and have clay-enriched B horizons. They form from weathered parent material in older regions. Ultisols are low in natural fertility and high in acidity, so they require nutrient input and fertilizer to be productive for agriculture. They make up 8 percent of the world's ice free land area.

----

Vertisols exhibit a shrink-swell behavior with changing water content due to their high concentration of silicate clay. When the soil shrinks it forms deep cracks, which allow material to fall into it. This material will then be incorporated into the soil when the soil swells again. These typically form in warm climates in limestone, basalt, or topographic depressions. Vertisols make up 2 percent of the world's ice free land area.

== Soil Biodiversity ==

Soil biodiversity refer to the diversity of living [[organisms]] in the soil. The most biologically diverse part of the earth is the soil. The soil has a vast biological web of interactions between [[microorganisms]], plants, and [[macroorganisms]]. [[Bacteria]], [[fungi]], [[annelids]], spiders, [[collembola]], [[tardegrades]], [[springtail]], ants, and countless other organisms make up the diversity of the soil. These organisms are important to the flow of nutrients through the soil, which helps productivity. They help plants that grow on top of the soil by providing services like: retaining nutrients, preventing nutrient leeching, decomposing dead matter, returning nutrients to their mineral form, and improving water filtration by forming soil aggregates. The soil may not appear to be alive because many of the organisms are very small, but that does not mean it is not diverse in life. A handful of soil can contain a billion different [[organisms]].

== Citations ==

*Amundson, R., Guo, Y. & Gong, P. Ecosystems (2003) 6: 470.
*Bailey, Robert G. Description of the ecoregions of the United States. U.S. Dept. of Agriculture, Forest Service, 1995
*Guo, Yinyan, et al. “Pedodiversity in the United States of America.” Geoderma, vol. 117, no. 1-2, 2003, pp. 99–115.
*Brussaard, Lijbert. “Biodiversity and Ecosystem Functioning in Soil.” Ambio, vol. 26, no. 8, 1997, pp. 563–570.
*Wardle, D. A. (2006), The influence of biotic interactions on soil biodiversity. Ecology Letters, 9: 870–886.
*Diana H. Wall, John C. Moore; Interactions Underground: Soil biodiversity, mutualism, and ecosystem processes, BioScience, Volume 49, Issue 2, 1 February 1999, Pages 109–117

Diversity

2018-05-11T13:59:06Z

Serenani: /* Soil Biodiversity */

Diversity is defined as the state of being diverse, having a variety. Diversity is apparent in many aspects of [[soil]]. Two examples of soil diversity are the different soil orders and the soil biodiversity.

== Soil Orders in the United States ==

[[File:4-Figure1-1.png|500px|thumb|left| Soil orders in the United States]]

The United States exhibits a vast array of soil orders, as shown in the image to the left. The soil orders included in this map are: Alfisols, Andisols, Aridsols, Entisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, and Vertisols.

Alfisols have a base saturation over 35 percent and have subsoil horizons enriched with clay. This type of soil is typically found under forest and savanna vegetation. Alfisoils are generally fertile, with production levels similar to that of Mollisols and Ultisols. They are typically abundant in nutrient cations of Ca, Mg, K, and Na. They make up about 10 percent of the world's ice free land areas.

----

Andisols form in or near areas of recent volcanism and are made from volcanic parent materials unique chemical properties. They have limited geographic distribution, but have potentially high productivity due to their tendency to accumulate organic material, and are easily cultivated. They lack development of [[soil horizons]] and are not typically extensively weathered. They make up about 1 percent of the worlds ice-free land areas.

----

Aridsols are soils in arid climates that have visible chemical/weathering alteration. They often have accumulation of CaCo3(lime) and NaCl(salt), but normally have low amounts of organic matter content. Aridsols normally are water deficient, and do not allow for the growth of crops without irrigation. Without irrigation and fertilization, the productivity of Aridsols are generally low. They make up 12 percent of the world's ice free land areas.

----

Entisols lack development of [[Soil Horizons]]. This type of soil can be formed from a wide variety of parent material, making its properties and productivity varied. These soils are often found in dry or cool environments, commonly being found with Aridsols. Very productive Entisols can be found on floodplains, while low productivity in this soil can be found on steep slopes or sandy areas. They make up 16 percent of the world's ice free land areas.

----

Histosols are soils that are mainly composed of organic materials. The organic matter accumulates because the soil is usually very saturated, which creates anerobic conditions that cause the accumulation of organic matter to be faster than decompostion. These soils are typically found in wetland environments and make up 1 percent of the world's ice free land areas.

----

Inceptisols are freely draining soils soils that exhibit beginning stages of soil horizon development. This type of soil is typically found in mountain areas and have a varied productivity. They make up 10 percent of the world's ice free land areas.

----

Mollisols typically develop in grasslands and have a thick organic-rich A horizon. This type of soil is extremely productive due to its saturation of the cations Ca2+, Mg2+, Na+, and K+. All of those cations are essential plant nutrients. This type of soil makes up 7 percent of the worlds ice free land areas.

----

Oxisols are typically found in the tropics and are highly chemically altered. These soils are naturally low in fertility and high in acidity. They are leeched and require fertilizers and an input of nutrients in order to be productive for agriculture. This type of soils makes up 8 percent of the world's ice free land area.

----

Spodosols are coarse-textured soils with high leeching potential. They are typically located in northern latitude forests, forming from sandy parent material. The Fe and Al compounds in this soil have a strong geochemical separation. This soil is naturally low in fertility and high in acidity, like Oxisols. This soil requires nutrient input and fertilizers in order to be productive for agriculture. This type of soil makes up 4 percent of the world's ice free land area.

----

Ultisols occur in warm, humid climates and have clay-enriched B horizons. They form from weathered parent material in older regions. Ultisols are low in natural fertility and high in acidity, so they require nutrient input and fertilizer to be productive for agriculture. They make up 8 percent of the world's ice free land area.

----

Vertisols exhibit a shrink-swell behavior with changing water content due to their high concentration of silicate clay. When the soil shrinks it forms deep cracks, which allow material to fall into it. This material will then be incorporated into the soil when the soil swells again. These typically form in warm climates in limestone, basalt, or topographic depressions. Vertisols make up 2 percent of the world's ice free land area.

== Soil Biodiversity ==

Soil biodiversity refer to the diversity of living [[organisms]] in the soil. The most biologically diverse part of the earth is the soil. The soil has a vast biological web of interactions between [[microorganisms]], plants, and [[macroorganisms]]. [[Bacteria]], [[fungi]], [[annelids]], spiders, [[collembole]], [[tartigrades]], [[springtail]], ants, and countless other organisms make up the diversity of the soil. These organisms are important to the flow of nutrients through the soil, which helps productivity. They help plants that grow on top of the soil by providing services like: retaining nutrients, preventing nutrient leeching, decomposing dead matter, returning nutrients to their mineral form, and improving water filtration by forming soil aggregates. The soil may not appear to be alive because many of the organisms are very small, but that does not mean it is not diverse in life. A handful of soil can contain a billion different [[organisms]].

== Citations ==

*Amundson, R., Guo, Y. & Gong, P. Ecosystems (2003) 6: 470.
*Bailey, Robert G. Description of the ecoregions of the United States. U.S. Dept. of Agriculture, Forest Service, 1995
*Guo, Yinyan, et al. “Pedodiversity in the United States of America.” Geoderma, vol. 117, no. 1-2, 2003, pp. 99–115.
*Brussaard, Lijbert. “Biodiversity and Ecosystem Functioning in Soil.” Ambio, vol. 26, no. 8, 1997, pp. 563–570.
*Wardle, D. A. (2006), The influence of biotic interactions on soil biodiversity. Ecology Letters, 9: 870–886.
*Diana H. Wall, John C. Moore; Interactions Underground: Soil biodiversity, mutualism, and ecosystem processes, BioScience, Volume 49, Issue 2, 1 February 1999, Pages 109–117

Plant roots

2018-05-11T13:57:43Z

Serenani: /* Citations */

== Overview ==

The root is typically the part of the plant that grows into the [[soil]], although it can be aerial in waterlogged soil. Roots have two main functions, anchoring the plant to the ground, and absorbing nutrients, water, and minerals for the plant. There are two main types of roots, tap roots and fibrous roots, both of which are explained in this page. Plant root systems can be very extensive, and are harder to study than the above ground biomass. Current methods for studying root systems include: the [[harvest method]], [[isotopic analysis]], [[root ingrowth]], and [[rhizotrons]]. Roots can often have symbiotic relationships with [[Ectomycorrhizal Fungi]] and [[Arbuscular Mycorrhizal Fungi]].

== Parts of the plant root ==
[[File:partsofroots.jpg|300px|thumb|left|Parts of the Root. Source: Biology Junction]] [[File:Root_Crosssection.jpg|300px|thumb|left|Root Cross Section. Source: Encyclopædia Britannica, Inc.]]

; Root Hairs
:The root hairs are thin hairlike structures growing from the epidermis. These help with the absorption of moisture and nutrients from the soil, which is then transported to the rest of the plant. The majority of plant water absorption happens with the root hairs. The length and shape allows them to have a large surface area while being able to go between soil particles, both of which helps with water absorption. In legume plants, they are involved in root nodule formation.

; Xylem
:In vascular plants, xylem transports nutrients and water in a sap from the roots to the stem and leaves. It uses passive transportation, so it does not need an input of energy to operate. The xylem is primarily composed of dead cells, and can only flow upward. This movement is mainly driven by negative pressures.

;Phloem
:In vascular plants, phloem transports the products of photosynthesis in a sap from the chloroplast down to the roots or storage structures. The sap holds a lot of sucrose, but is water-based. The phloem is primarily composed of living cells and is able to flow in many different directions. It's flow is called translocation, and is mainly caused by positive hydrostatic pressures.

;Pericycle
:The pericycle is made up of sclerenchyma or parenchyma cells in a cylindrical shape. In dicots, it gives protection to vascular bundles and strengthens the roots. In eudicots, it can create lateral roots, which grow horizontally and help anchor the plant.

;Endodermis
:The endodermis is the innermost layer of the cortex. The outer ring of the epidermis is deposited with the casparian strip, which helps stop the flow of water from around the cell membranes. This helps to regulate the water that flows into or out of the xylem, and stops gas bubbles from reaching the xylem.

;Apical meristem
:The apical meristem is full of actively dividing cells. It allows for primary growth, where the plant grows up and down.

;Root cap
:The root cap protects the growing apical meristem by secreting a mucus that eases the movement of the root through the soil.

;Epidermis
:The epidermis is the outerlayer of cells on the root. It absorbs water and nutrients, regulates gas exchange, stops water loss, and puts out metabolic compounds. It is covered in stomata, which is a pore that regulates water vapor and gas exchange.

== Types of plant roots ==

[[File:rootsystems.gif|300px|thumb|left|Types of Roots. Source: National Gardening Association, Inc.]]
;Tap Roots
:Tap roots typically are large roots that grow downward, which other roots laterally sprout from. Some tap roots will persist for the entire plant life, but most plants will replace them with a fibrous system. [[Dicots]] are an example of plants that start with a tap root system. In some plants, like carrots, the tap root is later developed into an organ for storage. Most plants replace the tap root with the fibrous root because the tap roots grows from the radicle of the plant, which often dies after germination, forcing it to switch.

;Fibrous Roots
:Fibrous roots grow out of the stem and are made up of many thin branching roots. This can spread widely in the soil, sometimes becoming larger than the above ground plant. This type of root system can be seen in [[monocots]], such as grasses.

;Adventitious Roots
:Although tap roots and fibrous roots are the primary root system seen, adventitious roots are sometimes seen. These roots arise from the stem or a leaf, often being seen on plants that have an underground stem. Some of these roots are aerial, being completely or partially above the soil. Examples of plants that have these roots are mangroves, bamboo, and corn.

;Other Specialized Roots Systems
:There are various other specialized root systems that are not as common to see. For example, some parasitic plants have root projections called haustoria, which penetrate the hosts tissues and absorb its nutrients. Another example of a specialized root system is pneumatophores, which can be seen on swamp plants. These roots are aerial and allow for gas exchange in the water-logged soil.

== Citations ==

*Gyssels, G., et al. “Impact of Plant Roots on the Resistance of Soils to Erosion by Water: a Review.” Progress in Physical Geography, vol. 29, no. 2, 2005, pp. 189–217.
*Cannon, William Austin. “A Tentative Classification of Root Systems.” Ecology, vol. 30, no. 4, 1 Oct. 1949, pp. 542–548.
*Glinski, J. Soil Physical Conditions and Plant Roots. CRC Press, 2018.
*Russell, Robert Scott. Plant Root Systems: Their Function and Interaction with the Soil. English Language Book Society and McGraw-Hill, 1982.
*Esau, K. 1965. Plant Anatomy, 2nd Edition. John Wiley & Sons. 767 pp.
*Beeckman, Tom; De Smet, Ive (2014). "Pericycle". Current Biology. 24 (10): R378–9
*Britannica, The Editors of Encyclopaedia. “Root.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 Apr. 2018
*Sutton, R. F.; Tinus, R. W. (1983). "Root and root system terminology". Forest Science Monograph. 24: 137.
*Coutts, M. P. (1987). "Developmental processes in tree root systems". Canadian Journal of Forest Research. 17: 761–767. doi:10.1139/x87-122

Serenani:

Foraging

2018-05-09T05:34:22Z

Serenani: /* Optimal Foraging Theory */

Many animals forage in the soil, looking for food such as plants or smaller organisms.

== Optimal Foraging Theory ==

The optimal foraging theory predicts how a foraging animal will behave when presented with a choice in its prey. This theory takes into account not only the energy the organism receives from the prey, but also the energy and time it costs to forage for the prey. Animals want to receive the greatest benefit of energy while expending the least amount of their own time and energy. The goal of this theory is to find the foraging strategy that maximizes the energy the species receives under the constraints of it's environment. These constraints can include how long it takes for the animal to travel to the foraging sites, how long it takes to search for the prey, how long it takes for the animal to prepare its foraged prey for eating, along with other factors. The optimal diet model can be used to find the optimal foraging strategy.

'''Optimal Diet Model'''

In this model, predators have to decide whether to eat the prey they find or look for another, hopefully more profitable, source of prey. Animals have to choose between big prey and large prey. They do this by considering the handling time (how long it takes to prepare the prey for eating), search time, and energy they would gain. To determine the profitability in this model, the value of energy the animal will receive should be divided by the handling time. The prey with the larger number is more profitable. However, if the predator comes across one prey and has to decide whether to eat it or look for another source of prey, search time for that second prey has to be taken into consideration. If the the energy value divided by the handling time plus the search time of the second prey is greater than the energy value divided by the handling time of the first prey, then the animal should search for the other source of prey. Shown in an equation, the animal should only search for the second source of prey if E2/(h2+S2) > E1/h1. In this equation E1 and E2 are the energy values benefited from prey 1 and prey 2, respectively, h1 and h2 are the handling time of prey 1 and prey 2, and S2 is the search time for prey 2. If S2 is in a certain value threshold, the animal will eat both prey. These animals that eat both prey are often generalists, while animals that do not are often specialists.

[[File:Functional response curve.jpg]] The search time depends on the density of prey. Functional response curves are used to plot the rate of prey capture over the prey density. There are type 1, type 2, and type 3 response curves. In type 1, there is a linear relationship between rate of prey captured and prey density. As the rate of prey capture increases, so does prey density. In type 2 response curves, the rate of prey captured increases with prey density to a point, and then flattens out because the predators become satiated. In type 3 response curves, rate of prey capture is high at low prey densities because the predators are more generalists and eat whatever is most abundant. At high prey densities, the predators will become specialists and pick the prey that is the most beneficial, not just the most abundant.

https://www.sciencedirect.com/science/article/pii/S003140560470075X

Foraging

2018-05-09T05:12:32Z

Serenani: /* Optimal Foraging Theory */