Global acceleration in rates of vegetation change over the past 18,000 years

Abstract

Global vegetation over the past 18,000 years has been transformed first by the climate changes that accompanied the last deglaciation and again by increasing human pressures; however, the magnitude and patterns of rates of vegetation change are poorly understood globally. Using a compilation of 1181 fossil pollen sequences and newly developed statistical methods, we detect a worldwide acceleration in the rates of vegetation compositional change beginning between 4.6 and 2.9 thousand years ago that is globally unprecedented over the past 18,000 years in both magnitude and extent. Late Holocene rates of change equal or exceed the deglacial rates for all continents, which suggests that the scale of human effects on terrestrial ecosystems exceeds even the climate-driven transformations of the last deglaciation. The acceleration of biodiversity change demonstrated in ecological datasets from the past century began millennia ago.

Ecosystem impacts by the Ancestral Puebloans of Chaco Canyon, New Mexico, USA

“…Additionally, what we have observed from the Ancestral Puebloan existence at Chaco Canyon ostensibly was part of a larger global phenomenon of unprecedented acceleration of vegetation compositional change that began between 3 and 5 thousand years ago [ 84 ]. This trend of cultural shaping of landscapes was not unique to the Chaco Canyon settlers and was well underway in most terrestrial ecosystems by the time of the Bonito phase.…”

Bottom-up versus top-down megafauna–vegetation interactions in ancient Beringia

“…Carbon dioxide concentrations rose by 50%, triggering a global warming of 6 °C to 7 °C ( 10 , 11 ) and the melting of ice sheets worldwide, raising sea level by over 100 m. Populations of an evolutionarily novel species (humans) were expanding worldwide. Plant and animal ranges shifted individualistically by up to hundreds to thousands of kilometers in the midlatitudes and upper latitudes, leading to rapid rates of change ( 12 ) and mixtures of species with no modern analog. Globally, two-thirds of large terrestrial vertebrate species went extinct during the Late Quaternary ( 13 ), while fire regimes intensified ( 14 ).…”

Vegetation Response to Holocene Climate Change in the Qinling Mountains in the Temperate–Subtropical Transition Zone of Central–East China

“…Pollen is an important indicator for the reconstruction of past plant diversity. There have been many studies on plant diversity based on the palynological diversity (Xiao et al, 2008;Liang et al, 2019;Rudaya et al, 2020;Mottl et al, 2021). Even though there are several uncertainties involved in reconstructing plant diversity from fossil pollen records.…”

“…However, several studies have shown that increased temperatures are conducive to plant growth at high latitudes (Peuelas and Filella, 2001), while at the same time, the vegetation at high latitudes and altitudes is more sensitive to climate change (Pepin et al, 2015;Ellis et al, 2021). Human activities also have important direct impacts on terrestrial ecosystems (Vitousek, 1994;Crutzen and Stoermer, 2000;Crutzen, 2002;Mottl et al, 2021). Humans altered the land surface, ecosystem dynamics and biodiversity by clearing the native vegetation for agriculture and living space, which has led to increased species extinctions, with rates accelerating during the past few centuries and with potentially irreversible effects (Braatz et al, 1992;Pimm et al, 2014;Lewis and Maslin, 2015).…”