Écologie, extinctions…

Are we eating the world’s megafauna to extinction?
Ripple et al.
Conservation letters, 2019

Surprisingly, direct harvesting of megafauna for human consumption of meat or body parts is the largest individual threat to each of the classes examined, and a threat for 98% (159/162) of threatened species with threat data available. Therefore, minimizing the direct killing of the world’s largest vertebrates is a priority conservation strategy that might save many of these iconic species and the functions and services they provide.

Population reconstructions for humans and megafauna suggest mixed causes for North American Pleistocene extinctions
Broughton & Weitzel
Nature communications, 2018

The results suggest that the causes for extinctions varied across taxa and by region. In three cases, extinctions appear linked to hunting, while in five others they are consistent with the ecological effects of climate change and in a final case, both hunting and climate change appear responsible.

The Evidence for Human Agency in the Late Pleistocene Megafaunal Extinctions
G Haynes.
Encyclopedia of the anthropocene, 2018

But the extinctions at the end of the Pleistocene are uniquely different because they unfolded almost instantly on an evolutionary timescale and had a disproportionate bias for megafauna, a term once applied to any animal larger than a rabbit and now meaning animals with average adult body mass44 or 45 kg (100 lbs). Alroy (2001, p. 1893) deemed the Late Pleistocene extinctions “unparalleled in the deeper fossil record” of North America, which they also seem to be on the other continents. This set of extinctions is not just another example of natural processes eliminating many animal genera; it is a first sign of irreversible human effects on the biosphere.

Plio-Pleistocene decline of African megaherbivores: No evidence for ancient hominin impacts
Faith et al.
Science, 2018

The large mean body size of mammalian herbivores explains the productivity paradox during the Last Glacial Maximum
Dan Zhu et al.
Nature ecology and evolution, 2018

The present-day results of potential grazer biomass, combined with an empirical land-use map, infer a reduction in wild grazer biomass by 79–93% owing to anthro-pogenic land replacement of natural grasslands. For the LGM, we find that the larger mean body size of mammalian herbivores than today is the crucial clue to explain the productivity paradox, due to a more efficient exploitation of grass production by grazers with a large body size


Pleistocene megafaunal interactionnetworks became more vulnerable afterhuman arrival
Pires et al.
Proceedings of the royal society, 2015

We show Pleistocene and modern assemblages share similar network topology, but differences in richness and body size distributions made Pleistocene communities significantly more vulnerable to the effects of human arrival. The structural changes promoted by humans in Pleistocene networks woul dhave increased the likelihood of unstable dynamics, which may favour extinction cascades in communities facing extrinsic perturbations.

A continent-wide assessment of the form and intensity of large mammal herbivory in Africa
Hempson et al.
Science, 2015

Hempson 2015 biomass to rainfall

Precipitation on land versus distance from the ocean: Evidence for a forest pump of atmospheric moisture
Makarieva et al.
Ecological complexity, 2009

Our results indicate that forest cover plays a major role in the atmospheric circulation and water cycling on land. This suggests a good potential for forest-mediated solutions of the global desertification and water security problems.