一萬兩千年前南美洲大型草食動物的減少導(dǎo)致亞馬遜流域的營養(yǎng)物質(zhì)橫向運輸?shù)南陆?，這也可以解釋為何今天的亞馬遜盆地可用磷元素變得有限,，9月《自然—地球科學(xué)》上的一項研究給出上述結(jié)論,。
Christopher Doughty等人利用模型演示了諸如大型樹獺和犰狳類雕齒獸一類的遠(yuǎn)古巨型動物會通過糞便和身體攜帶的方式將營養(yǎng)物質(zhì)從高濃度區(qū)域帶向周邊地區(qū),。他們通過一系列的計算發(fā)現(xiàn),，這些動物的滅絕會伴有地區(qū)間營養(yǎng)物質(zhì)橫向運輸?shù)娘@著減少,。這種情況在亞馬遜盆地是最顯著的,，減少率最高可達(dá)98%,，但美洲,、歐亞和澳洲地區(qū)也普遍存在這種現(xiàn)象。
Tanguy Daufresne在一篇評論文章中稱“隨著那些對營養(yǎng)物質(zhì)分布起促進(jìn)作用的巨型動物的印記逐漸消逝,，現(xiàn)在也許是時候追問生物地球化學(xué)給全球帶來的后果了”,。（生物谷 Bioon.com）
生物谷推薦的英文摘要
Nature Geoscience doi:10.1038/ngeo1895
The legacy of the Pleistocene megafauna extinctions on nutrient availability in Amazonia
Christopher E. Doughty, Adam Wolf & Yadvinder Malhi
In the late Pleistocene, 97 genera of large animals went extinct, concentrated in the Americas and Australia1. These extinctions had significant effects on ecosystem structure2, seed dispersal3 and land surface albedo4. However, the impact of this dramatic extinction on ecosystem nutrient biogeochemistry, through the lateral transport of dung and bodies, has never been explored. Here we analyse this process using a novel mathematical framework that analyses this lateral transport as a diffusion-like process, and we demonstrate that large animals play a disproportionately large role in the horizontal transfer of nutrients across landscapes. For example, we estimate that the extinction of the Amazonian megafauna decreased the lateral flux of the limiting nutrient phosphorus by more than 98%, with similar, though less extreme, decreases in all continents outside of Africa. This resulted in strong decreases in phosphorus availability in eastern Amazonia away from fertile floodplains, a decline which may still be ongoing. The current P limitation in the Amazon basin may be partially a relic of an ecosystem without the functional connectivity it once had. We argue that the Pleistocene megafauna extinctions resulted in large and ongoing disruptions to terrestrial biogeochemical cycling at continental scales and increased nutrient heterogeneity globally.
