A Little Help From Their Friends

Animals are a tree's best friend

• Hannah Schardt
• Aug 01, 2008

IF A TREE WANTS to spread its seed—and what tree doesn’t?—the best way to do it is to enlist the help of its animal friends. That’s according to a new study by researchers in Spain and the United Kingdom, which finds that tree seeds lodged in fur or feathers or eaten along with fruit tend to fall on better planting sites than those that are simply scattered by the wind. The scientists looked at nearly 90,000 forest plots across Spain and found that 24 out of 34 tree species suffered from the fragmentation and disappearance of forestland. But there was a strikingly wide range of responses among the species, and the trees that did better had one thing in common: Their seeds are dispersed by animals.

The Spanish researchers who conducted the study say that those differences in dispersal may explain why some tree species survive while others disappear when the surrounding forest is fragmented—and may help dictate future conservation policy.