Fall Foliage Timing Comes into Clearer Focus

By | October 20, 2015

In Autumn, New England foliage[植物；叶子] turns vibrant shades[充满生气的;有活力的 颜色] of red, yellow, and orange. Which brings in lots of green—as in the money spent by tourists who flock to[涌到] the region to witness the explosion of color.

Because of fall’s economic implications[经济意义;影响;含义], exactly when the leaf-peeping season will begin is thus a source of constant speculation[不断的推测].

Scientists know that factors including frost, heat, rain and drought all affect the timing—but the whole colorful picture is still difficult to accurately predict.

Now scientists have picked apart satellite imagery[卫星图，卫星影像] from two New England forest ecosystems[森林生态系统] collected from 2001 to 2012 to try to get a better handle on exactly what factors influence the autumn leaves.

The scientists looked at northeastern highlands[高原地区；山岳地带] and coastal zones[海岸带]. They incorporated available data on chills[寒冷；冷漠], frosts[霜；冰冻] and heat, and rain, drought, and flooding. In general, cold, wet and extreme heat made leaves change color sooner, while moderate heat[小暑,中火] and low rainfall delayed the coloration[着色；染色].

But the different ecosystems behaved differently. Forests in the highlands reacted to frosts both in spring and in the fall, while the coast only responded to fall frosts. The coastal region’s forests were also particularly sensitive to rain and flooding.

Incorporating climate change predictions for the next century, the researchers propose[建议；打算，计划;提出] that the highlands will change color later in the fall, while the coast may start to turn earlier. The study is in the Proceedings of the National Academy of Sciences[美国科学院论文集].

The researchers note that more data, such as for extreme weather events[极端气候事件] and flooding, need to be incorporated into[使成为…的一部分] future models. Which could help New England states maximize fall’s economic windfall[意外之财；被风吹落的果子；意外的收获].

From 60-Second Science