Editing Ecological niche (section)

====Resource partitioning====

Resource partitioning is the phenomenon where two or more species divides out resources like food, space, resting sites etc. to coexist. For example, some lizard species appear to coexist because they consume insects of differing sizes.<ref name="Caldwell1999">{{cite journal|last1=Caldwell|first1=Janalee P|last2=Vitt|first2=Laurie J|title=Dietary asymmetry in leaf litter frogs and lizards in a transitional northern Amazonian rain forest|journal=Oikos|date=1999|volume=84|issue=3|pages=383–397|doi=10.2307/3546419|jstor=3546419|bibcode=1999Oikos..84..383C }}</ref>  Alternatively, species can coexist on the same resources if each species is limited by different resources, or differently able to capture resources.  Different types of [[phytoplankton]] can coexist when different species are differently limited by nitrogen, phosphorus, silicon, and light.<ref name="Grover1997book">{{cite book|last1=Grover|first1=James P.|title=Resource competition|date=1997|publisher=Chapman & Hall|location=London|isbn=978-0412749308|edition=1st}}{{page needed|date=March 2018}}</ref>  In the [[Galapagos Islands]], [[Darwin's finches|finches]] with small beaks are more able to consume small seeds, and finches with large beaks are more able to consume large seeds.  If a species' density declines, then the food it most depends on will become more abundant (since there are so few individuals to consume it).  As a result, the remaining individuals will experience less competition for food.

Although "resource" generally refers to food, species can partition other non-consumable objects, such as parts of the habitat.  For example, [[warbler]]s are thought to coexist because they nest in different parts of trees.<ref name=MacArthur1958>{{cite journal|last1=MacArthur|first1=Robert H.|title=Population Ecology of Some Warblers of Northeastern Coniferous Forests|journal=Ecology|date=October 1958|volume=39|issue=4|pages=599–619|doi=10.2307/1931600|jstor=1931600|bibcode=1958Ecol...39..599M }}</ref>  Species can also partition habitat in a way that gives them access to different types of resources.  As stated in the introduction, [[anole]] lizards appear to coexist because each uses different parts of the forests as perch locations.<ref name=Pacala&Roughgarden1985 />  This likely gives them access to different species of insects.

Research has determined that plants can recognize each other's root systems and differentiate between a clone, a plant grown from the same mother plants seeds, and other species. Based on the root secretions, also called exudates, plants can make this determination.<ref name="Biedrzycki 4123–4128">{{Cite journal |last1=Biedrzycki |first1=M. L. |last2=Bais |first2=H. P. |date=2010-08-08 |title=Kin recognition in plants: a mysterious behaviour unsolved |url=http://dx.doi.org/10.1093/jxb/erq250 |journal=Journal of Experimental Botany |volume=61 |issue=15 |pages=4123–4128 |doi=10.1093/jxb/erq250 |pmid=20696656 |issn=0022-0957}}</ref> The communication between plants starts with the secretions from plant roots into the rhizosphere. If another plant that is kin is entering this area the plant will take up exudates. The exudate, being several different compounds, will enter the plants root cell and attach to a receptor for that chemical halting growth of the root meristem in that direction, if the interaction is kin.<ref>{{Cite journal |last=Witzany |first=Günther |date=July 2006 |title=Plant Communication from Biosemiotic Perspective |journal=Plant Signaling & Behavior |volume=1 |issue=4 |pages=169–178 |doi=10.4161/psb.1.4.3163 |pmid=19521482 |pmc=2634023 |s2cid=5036781 |issn=1559-2324|doi-access=free |bibcode=2006PlSiB...1..169W }}</ref>

Simonsen discusses how plants accomplish root communication with the addition of beneficial rhizobia and fungal networks and the potential for different genotypes of the kin plants, such as the legume M. Lupulina, and specific strains of nitrogen fixing bacteria and rhizomes can alter relationships between kin and non-kin competition.<ref>{{Cite journal |last1=Simonsen |first1=Anna K. |last2=Chow |first2=Theresa |last3=Stinchcombe |first3=John R. |date=December 2014 |title=Reduced plant competition among kin can be explained by Jensen's inequality |journal=Ecology and Evolution |language=en |volume=4 |issue=23 |pages=4454–4466 |doi=10.1002/ece3.1312 |issn=2045-7758 |pmc=4264895 |pmid=25512842|bibcode=2014EcoEv...4.4454S }}</ref> This means there could be specific subsets of genotypes in kin plants that selects well with specific strains that could outcompete other kin.<ref name="Biedrzycki 4123–4128"/> What might seem like an instance in kin competition could just be different genotypes of organisms at play in the soil that increase the symbiotic efficiency.