GreenSpace: Coffee that perks up the birds and forests

The Baltimore orioles of our region's woodlots have long since flown south.

By now, they're likely in Latin America, chasing exotic forest canopy insects.

I would enjoy pouring a cup of coffee and staring out the window at winter birds to contemplate all this. But first, I have to decide: Which coffee?

With each sip, I can help the orioles - plus a lot of other species, including the farmers and, according to new research, the forest itself.

The key is shade.

For generations, farmers have tended coffee plants beneath a thick canopy of trees.

But in the early 1970s, coffee farming started to become "technified." Sun-brown monocultures - growing one crop over a large area - produced higher yields. Good, right? Except they had to be slathered with pesticides and drenched with fertilizer.

By now, according to the Smithsonian National Zoological Park, also known as the National Zoo, which has studied the issue, about 70 percent of coffee-growing areas in Colombia alone are "technified."

Only now are researchers grasping the effects: more erosion, polluted runoff, and loss of species.

Traditional shade farms have teeming populations of rare orchids, wildly colorful frogs, swarms of native bees. Smithsonian biologists have found that shade farms can support more than 150 bird species, a number exceeded only in undisturbed tropical forests.

Reduce the shade, and the number of bird species drops as much as 97 percent.

On a visit to El Salvador, Academy of Natural Sciences ornithologist Nate Rice was appalled at the mountainsides of coffee growing in the sun. While he suspects it passed as shade-grown because "they leave hedgerows and the odd big tree," there was hardly a bird to be found.

University of Michigan doctoral ecologist Shalene Jha found that traditional shade farms could be focal points for tropical forest regeneration.

She looked at the DNA "fingerprints" of a tree species in Mexico called Miconia affinis, common on shade farms. It has purplish berries that are dispersed only by birds and bats.

How well were they doing their job? Jha found closely related trees were spread as far as two kilometers apart in shady areas.

Jha's research was published last month in the journal Current Biology.

All this amounts to more than just a hill of beans. The traditional shade farm is a complex synergistic system, where nitrogen-fixing trees fertilize the plants, which attract insects to feed the birds, which spread the tree seeds . . . and so on.