干旱区生态环境知识资源中心(Arid): Impacts of fungus-growing termites on surficial geology parameters: A review

Arid

DOI	10.1016/j.earscirev.2021.103862
	Impacts of fungus-growing termites on surficial geology parameters: A review
	Van Thuyne, John; Verrecchia, Eric P.
通讯作者	Van Thuyne, J (corresponding author), Univ Lausanne, Fac Geosci & Environm, Inst Earth Surface Dynam, CH-1015 Lausanne, Switzerland.
来源期刊	EARTH-SCIENCE REVIEWS
ISSN	0012-8252
EISSN	1872-6828
出版年	2021
卷号	223
英文摘要	This review covers more than twenty-five years of research listing and discussing the biogeochemical, mineralogical, and physical impacts of fungus-growing termites (or FGT, Macrotermitinae sub-family) on savanna sediments and landscapes. The main mechanisms by which FGT transform the surficial geological formations in tropical and sub-tropical environments is investigated from a geological perspective and the potential FGT legacies in the sedimentary facies are identified. In order to sustain a twenty million-year symbiosis with the fungus, in which fungi provide digestible food to termites, FGT must optimize the living conditions of the fungus for it to thrive. To do so, they build a biogenic structure maintaining a constant humidity of 80% and a temperature of 30 degrees C in any kind of environment and all year long. Indeed, FGT adapt to their environment by (i) modifying the grain-size distributions of sediments and soils where they develop, (ii) forming clay horizons below their mounds enabling water to be stored for long period of time in dry environments, (iii) increasing the alkalinity by an order of magnitude of two to three, (iv) mineralizing around 20% of all organic carbon in dry savannas, thus making them the predominant decomposing organisms and crucial actors in the carbon cycle, and (v) concentrating vital nutrients for plants and animals, creating patches of fertile land in sandy semi-deserts. Through their mound-building activities, termites substantially increase the clay fraction compared to the adjacent soil and alter 2:1 clay properties, particularly after the removal of potassium, leading to the formation of smectite layers, demonstrating their biogeochemical effects on silicate mineralogy. Through the binding of aggregates, FGT increase the strength of the mound by a factor of ten and provide exceptional weathering resistance to their mounds. Therefore, termites impact their environment from sub-millimetric transformations to solid voluminous landmarks. The water-holding capacity of a FGT mound leads to an array of positive feedbacks to the savanna landscape by enhancing protection from fires, delaying desertification, supporting rebounds by seedlings and reinforcing dryland resistance and recovery from drought. Termite bioturbation allows sediments to accumulate at a rate averaging 1 mm.y(-1).ha(-1), and tends to mitigate physical and chemical processes of soil degradation, boosting the heterogeneity at the landscape scale, providing it more resilience. Some of the modifications brought by FGT will remain in the landscape for long periods, testifying to past environmental conditions, and making these mounds potential proxies for paleoenvironmental reconstructions. To conclude, FGT are not only biological actors of the savanna ecosystem, but they act as a geological force by their impact on landscapes as well as by their major role in biogeochemical cycles. Finally, further research is recommended regarding the role of termite's saliva as a binding agent, as well as the age and the evolution of mounds over time.
英文关键词	Insects Element cycle Soils and sediments Savanna Micromorphology
类型	Review
语种	英语
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:000721681900003
WOS关键词	MACROTERMES-BELLICOSUS ISOPTERA ; AFRICAN SAVANNA ; FEEDING TERMITE ; LUBUMBASHI AREA ; SOIL PROPERTIES ; MOUNDS ; CARBON ; NESTS ; SUBHYALINUS ; CLAY
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/374068
作者单位	[Van Thuyne, John; Verrecchia, Eric P.] Univ Lausanne, Fac Geosci & Environm, Inst Earth Surface Dynam, CH-1015 Lausanne, Switzerland; [Van Thuyne, John; Verrecchia, Eric P.] Van Thuyne Ridge Res Ctr, POB 301, Kasane, Botswana
推荐引用方式 GB/T 7714	Van Thuyne, John,Verrecchia, Eric P.. Impacts of fungus-growing termites on surficial geology parameters: A review[J],2021,223.
APA	Van Thuyne, John,&Verrecchia, Eric P..(2021).Impacts of fungus-growing termites on surficial geology parameters: A review.EARTH-SCIENCE REVIEWS,223.
MLA	Van Thuyne, John,et al."Impacts of fungus-growing termites on surficial geology parameters: A review".EARTH-SCIENCE REVIEWS 223(2021).