Thicket

[[Image:Betula pendula (fall colors) 2.jpg|thumb|upright=1.5|A thicket of silver birch ''Betula pendula'' in Saratov Oblast, Russia]] A '''thicket''' is a very dense stand of trees or tall shrubs,<ref name=":5">{{cite web |title=Definition of THICKET |url=https://www.merriam-webster.com/dictionary/thicket |website=www.merriam-webster.com |access-date=12 March 2021 |language=en}}</ref><ref>{{Cite journal |last1=Hoare |first1=David |last2=Mucina |first2=Ladislav |last3=Rutherford |first3=Michael |last4=Vlok |first4=Jan |last5=Euston-Brown |first5=Doug |last6=Palmer |first6=Anthony |last7=Powrie |first7=Leslie |last8=Lechmere-Oertel |first8=Richard |last9=Proches |first9=Serban |last10=Dold |first10=Anthony |last11=Ward |first11=Robert |date=2006 |title=Albany thicket biome |journal=The Vegetation of South Africa, Lesotho and Swaziland |series=Strelitzia |volume=19 |pages=541–567}}</ref> often dominated by only one or a few species to the exclusion of all others. They may be formed by species that shed large numbers of highly viable seeds that are able to germinate in the shelter of the maternal plants.

In some conditions, the formation or spread of thickets may be assisted by human disturbance of an area. Human disturbance and activity within thickets varies based on culture and location.

Where a thicket is formed of '''briar''' (also spelled '''brier'''), which is a number of unrelated thorny plants, it may be called a '''''briar patch'''''. Plants referred to with the term ''briar'' include species in the genera ''Rosa'' (Rose), ''Rubus'', and ''Smilax''.<ref>{{cite web |title=Definition of BRIAR |url=https://www.merriam-webster.com/dictionary/briar |website=www.merriam-webster.com |access-date=12 March 2021 |language=en}}</ref> A small group of trees is known as a '''copse'''.<ref name=":5" />

== Characteristics == Thickets are characterized by dense plant life, a low closed canopy, deep shale-derived soil, and high levels of soil carbon and nitrogen.<ref name=":0">{{Cite journal |last1=Cowling |first1=R. M. |last2=Potts |first2=A. J. |date=2015-11-01 |title=Climatic, edaphic and fire regime determinants of biome boundaries in the eastern Cape Floristic Region |journal=South African Journal of Botany |series=Biome Boundaries in South Africa |volume=101 |pages=73–81 |doi=10.1016/j.sajb.2015.03.182 |bibcode=2015SAJB..101...73C |issn=0254-6299|doi-access=free }}</ref> Plants present within a thicket generally reach a maximum of 4 to 6 meters in height.<ref name=":1">{{Cite journal |last1=Charles-Dominique |first1=T. |last2=Staver |first2=A. C. |last3=Midgley |first3=G. F. |last4=Bond |first4=W. J. |date=2015-11-01 |title=Functional differentiation of biomes in an African savanna/forest mosaic |journal=South African Journal of Botany |series=Biome Boundaries in South Africa |volume=101 |pages=82–90 |doi=10.1016/j.sajb.2015.05.005 |bibcode=2015SAJB..101...82C |issn=0254-6299|doi-access=free }}</ref> The boundaries between a thicket and its nearby forest are defined by a lack of precipitation and overall dry environment within the thicket area, while forests receive higher levels of precipitation.<ref name=":0" /> Forests also do not experience as much herbivory and browsing in comparison to thickets.<ref name=":1" />

The thicket biome has been identified in Africa, Madagascar, Australia, North America,<ref name=":2">{{Cite journal |last1=Archer |first1=Steve |last2=Scifres |first2=Charles |last3=Bassham |first3=C. R. |last4=Maggio |first4=Robert |date=1988 |title=Autogenic Succession in a Subtropical Savanna: Conversion of Grassland to Thorn Woodland |url=https://esajournals.onlinelibrary.wiley.com/doi/10.2307/1942463 |journal=Ecological Monographs |language=en |volume=58 |issue=2 |pages=111–127 |doi=10.2307/1942463 |jstor=1942463 |bibcode=1988EcoM...58..111A |hdl=1969.1/182277 |issn=0012-9615|hdl-access=free |url-access=subscription }}</ref> and South America. One of the most studied and well-recognized thickets is the Albany thicket biome, located in the Eastern Cape of South Africa.

Due to their overlapping ranges and similarity of plant species, thicket biomes may be misidentified as being portions of savannas. However, these areas can be differentiated through a thicket's lack of C4 grasses<ref name=":1" /> and relatively low fire exposure.<ref name=":0" />

== Significance and use ==

=== Ecological significance === While thickets tend to have a small number of plant species present, as they are often dominated by one species of tree or shrub, the biome provides ecological resources to a large group of species. Thickets frequently make up sections of the home ranges of native species, including ptarmigan and hares in the tundra,<ref>{{Cite journal |last1=Ehrich |first1=Dorothée |last2=Henden |first2=John-André |last3=Ims |first3=Rolf Anker |last4=Doronina |first4=Lilyia O. |last5=Killengren |first5=Siw Turid |last6=Lecomte |first6=Nicolas |last7=Pokrovsky |first7=Ivan G. |last8=Skogstad |first8=Gunnhild |last9=Sokolov |first9=Alexander A. |last10=Sokolov |first10=Vasily A. |last11=Yoccoz |first11=Nigel Gilles |date=2012-01-01 |title=The importance of willow thickets for ptarmigan and hares in shrub tundra: the more the better? |url=https://link.springer.com/article/10.1007/s00442-011-2059-0 |journal=Oecologia |language=en |volume=168 |issue=1 |pages=141–151 |doi=10.1007/s00442-011-2059-0 |pmid=21833646 |bibcode=2012Oecol.168..141E |issn=1432-1939|hdl=10037/3883 |hdl-access=free }}</ref> cheetahs<ref>{{Cite journal |last1=Bissett |first1=C. |last2=Bernard |first2=R. T. F. |date=2007 |title=Habitat selection and feeding ecology of the cheetah (Acinonyx jubatus) in thicket vegetation: is the cheetah a savanna specialist? |url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2006.00217.x |journal=Journal of Zoology |language=en |volume=271 |issue=3 |pages=310–317 |doi=10.1111/j.1469-7998.2006.00217.x |issn=0952-8369|url-access=subscription }}</ref> and lions<ref name=":3">{{Cite journal |last1=Davies |first1=Andrew B. |last2=Tambling |first2=Craig J. |last3=Kerley |first3=Graham I. H. |last4=Asner |first4=Gregory P. |date=2016-02-24 |title=Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket |journal=PLOS ONE |language=en |volume=11 |issue=2 |article-number=e0149098 |doi=10.1371/journal.pone.0149098 |doi-access=free |issn=1932-6203 |pmc=4766088 |pmid=26910832 |bibcode=2016PLoSO..1149098D }}</ref> in Africa, and frogs and alligators in North America.<ref name=":22">{{Cite journal |last1=Archer |first1=Steve |last2=Scifres |first2=Charles |last3=Bassham |first3=C. R. |last4=Maggio |first4=Robert |date=1988 |title=Autogenic Succession in a Subtropical Savanna: Conversion of Grassland to Thorn Woodland |url=https://esajournals.onlinelibrary.wiley.com/doi/10.2307/1942463 |journal=Ecological Monographs |language=en |volume=58 |issue=2 |pages=111–127 |doi=10.2307/1942463 |jstor=1942463 |bibcode=1988EcoM...58..111A |hdl=1969.1/182277 |issn=0012-9615|hdl-access=free |url-access=subscription }}</ref> In particular, a thicket's high plant density and resulting low visibility allows for predator species to succeed in tracking, stalking, and capturing their prey.<ref name=":3" />

=== Societal significance === Especially within the Albany thicket biome, thickets have traditionally been used for raising domestic livestock, although the popularity of doing so is declining over time.<ref name=":4">{{Cite journal |last1=Smith |first1=N |last2=Wilson |first2=S.L. |date=2002 |title=Changing land use trends in the thicket biome: pastoralism to game farming |journal=Terrestrial Ecology Research Unit Report |volume=38 |page=23}}</ref> Recently, the primary human activity taking place in thickets is game hunting, both for recreational purposes and for ecotourism. The increase in game hunting within thickets has also led to the rise of manmade game farms, which has prompted discussion regarding the impact of game farms on the biome and its health.<ref name=":4" /> Conservationists and biologists pose concern about the decrease in biodiversity that game farms may create, especially when coupled with other anthropogenic threats to thickets such as land clearing and urbanization.<ref>{{Cite journal |last1=Palmer |first1=Anthony |last2=Kakembo |first2=Vincent |last3=Lloyd |first3=Wendy |last4=Ainslie |first4=Andrew |date=2006 |title=Degradation Patterns and Trends in the Succulent Thicket |journal=Proceedings of the 2004 Thicket Forum}}</ref> Alternatively, farmers and many locals suggest that the formation of game farms is an effective manner in which to preserve land area and minimize human impact on a thicket.<ref name=":4" />

==References== {{reflist}} {{wikt|thicket}}

Category:Habitats Category:Habitat Category:Shrubs Category:Plant common names