Soil loss and resilience associated with end-Triassic deforestation
Publikation: Konferencebidrag › Konferenceabstrakt til konference › Forskning › fagfællebedømt
Soils are a crucial link between the atmosphere, biosphere, and geosphere and disturbances to the health of soils
will severely impact plants as well as a multitude of organisms living in or on soils. Catastrophic soil loss is
thought to have played a pivotal role during mass-extinction events as a result of major deforestation, but the
exact feedbacks remain elusive. Here, we assess the role of soil loss into the end-Triassic mass-extinction event
based on proxy data obtained from core material from France, Germany, England, Denmark, and Sweden. Clay
mineral and palynological data indicate a strong increase in chemical weathering and mechanical erosion during
the latest Rhaetian with the influx of kaolinite and abundantly reworked Palaeozoic organic matter. Based on a
new timeline, these changes were coeval with intense volcanic activity in the Central Atlantic Magmatic Province
(CAMP), which released large quantities of volatiles that contributed directly and indirectly to enhanced weathering. Erosion rates likely also rose in response to deforestation, repeated forest fires, and seismic activity related
to CAMP emplacement. Using a novel proxy based on biological degradation of fern spore walls, the intensity
of biodegradation by fungi and bacteria, a process coupled to organic matter decay in soils, strongly decreased
across the T/J boundary. We interpret this as evidence for the widespread removal of soils. Taken together, CAMP
induced environmental changes led to profound changes in weathering and erosion and removal of soils, while soil
resilience during the Hettangian proceeded hand in hand with recovery in Jurassic seas
will severely impact plants as well as a multitude of organisms living in or on soils. Catastrophic soil loss is
thought to have played a pivotal role during mass-extinction events as a result of major deforestation, but the
exact feedbacks remain elusive. Here, we assess the role of soil loss into the end-Triassic mass-extinction event
based on proxy data obtained from core material from France, Germany, England, Denmark, and Sweden. Clay
mineral and palynological data indicate a strong increase in chemical weathering and mechanical erosion during
the latest Rhaetian with the influx of kaolinite and abundantly reworked Palaeozoic organic matter. Based on a
new timeline, these changes were coeval with intense volcanic activity in the Central Atlantic Magmatic Province
(CAMP), which released large quantities of volatiles that contributed directly and indirectly to enhanced weathering. Erosion rates likely also rose in response to deforestation, repeated forest fires, and seismic activity related
to CAMP emplacement. Using a novel proxy based on biological degradation of fern spore walls, the intensity
of biodegradation by fungi and bacteria, a process coupled to organic matter decay in soils, strongly decreased
across the T/J boundary. We interpret this as evidence for the widespread removal of soils. Taken together, CAMP
induced environmental changes led to profound changes in weathering and erosion and removal of soils, while soil
resilience during the Hettangian proceeded hand in hand with recovery in Jurassic seas
Originalsprog | Engelsk |
---|---|
Publikationsdato | 2019 |
Antal sider | 1 |
Status | Udgivet - 2019 |
Begivenhed | EGU Galileo Conference: Mass extinctions, recovery and resilience - Utrecht, Holland Varighed: 28 aug. 2019 → 31 aug. 2019 Konferencens nummer: 5 https://meetingorganizer.copernicus.org/gc5-mass/sessionprogramme |
Konference
Konference | EGU Galileo Conference |
---|---|
Nummer | 5 |
Land | Holland |
By | Utrecht |
Periode | 28/08/2019 → 31/08/2019 |
Internetadresse |
- Det Natur- og Biovidenskabelige Fakultet
Forskningsområder
Links
- https://meetingorganizer.copernicus.org/GC5-Mass/GC5-Mass-52.pdf
Forlagets udgivne version
ID: 359341677