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Exploring the influence of ancient and historic megaherbivore extirpations on the global methane budget
- Source :
- Proceedings of the National Academy of Sciences. 113:874-879
- Publication Year :
- 2015
- Publisher :
- Proceedings of the National Academy of Sciences, 2015.
-
Abstract
- Globally, large-bodied wild mammals are in peril. Because "megamammals" have a disproportionate influence on vegetation, trophic interactions, and ecosystem function, declining populations are of considerable conservation concern. However, this is not new; trophic downgrading occurred in the past, including the African rinderpest epizootic of the 1890s, the massive Great Plains bison kill-off in the 1860s, and the terminal Pleistocene extinction of megafauna. Examining the consequences of these earlier events yields insights into contemporary ecosystem function. Here, we focus on changes in methane emissions, produced as a byproduct of enteric fermentation by herbivores. Although methane is ∼ 200 times less abundant than carbon dioxide in the atmosphere, the greater efficiency of methane in trapping radiation leads to a significant role in radiative forcing of climate. Using global datasets of late Quaternary mammals, domestic livestock, and human population from the United Nations as well as literature sources, we develop a series of allometric regressions relating mammal body mass to population density and CH4 production, which allows estimation of methane production by wild and domestic herbivores for each historic or ancient time period. We find the extirpation of megaherbivores reduced global enteric emissions between 2.2-69.6 Tg CH4 y(-1) during the various time periods, representing a decrease of 0.8-34.8% of the overall inputs to tropospheric input. Our analyses suggest that large-bodied mammals have a greater influence on methane emissions than previously appreciated and, further, that changes in the source pool from herbivores can influence global biogeochemical cycles and, potentially, climate.
- Subjects :
- Greenhouse Effect
0106 biological sciences
Rinderpest
010504 meteorology & atmospheric sciences
Climate
Population
Animals, Wild
Extinction, Biological
010603 evolutionary biology
01 natural sciences
Disease Outbreaks
Enteric fermentation
Megafauna
Animals
Humans
Human Activities
Ecosystem
Anaerobiosis
Herbivory
education
History, Ancient
0105 earth and related environmental sciences
Trophic level
Mammals
education.field_of_study
Carbon dioxide in Earth's atmosphere
Multidisciplinary
Extinction
Bison
Plant Dispersal
Ecology
Ice
Radiative forcing
Europe
Animals, Domestic
Fermentation
Environmental science
Digestion
Plants, Edible
Megafauna and Ecosystem Function: From the Pleistocene to the Anthropocene Special Feature
Animal Distribution
Methane
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 113
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....f0ef6a0ab82745dd44127aac5a380991