New genetic analysis has revealed that many Amazon tree species are likely to survive human-made climate warming in the coming century, contrary to previous findings that temperature increases would cause them to die out. A study, 1 in the latest edition of Ecology and Evolution, reveals the 2 age of some Amazonian tree species — more than 8 million years — and 3 shows that they have survived previous periods as warm as many of the global warming imagined periods 4 for the year 2100.
The authors write that, having survived warm periods in the past, the trees will 5 survive future warming, provided there are no other major environmental changes. 6 extreme droughts and forest fires will impact Amazonia as temperatures 7, the trees will stand the direct impact of higher temperatures. The authors 8 that as well as reducing greenhouse gas emissions to minimize the risk of drought and fire, conservation policy should remain 9 on preventing deforestation (采伐森林) for agriculture and mining.
The study disagrees with other recent researches which predicted tree species' extinctions 10 relatively small increases in global average air temperatures.
Study co-author Dr Simon Lewis (UCL Geography) said the 11 were good news for Amazon tree species, but warned that drought and over-exploitation of the forest remained major 12 to the Amazon's future.
Dr Lewis said: "The past cannot be compared directly with the future. While tree species seem likely to 13 higher air temperatures than today, the Amazon forest is being transformed for agriculture and 14, and what remains is being degraded (使恶化) by logging (伐木), and increasingly split up by fields and roads.
"Species will not move as freely in today's Amazon as they did in previous warm periods, when there was no human 15. Similarly, today's climate change is extremely fast, making comparisons with slower changes in the past 16. "
"With a clearer 17 of the relative risks to the Amazon forest, we 18 that direct human impacts — such as forest clearances for agriculture or mining — should remain a key point of conservation policy. We also need more aggressive 19 to reduce greenhouse gas emissions in order to make minimum the risk of drought and fire impacts and 20 the future of most Amazon tree species. "
