Shade coffee farms can play major role in tropical forest regeneration

Washington, Dec 23 (ANI): A study has found that shade coffee farms, which grow coffee under a canopy of multiple tree species, are beneficial for native birds, bats and other creatures, maintain genetic diversity of native tree species, and, can act as focal points for tropical forest regeneration.

The study was undertaken by University of Michigan researchers Shalene Jha and Christopher Dick.

Jha, a graduate student whose main interest is insects, initially wanted to find out whether shade coffee farms nurture native pollinators such as stingless bees.

When she began her fieldwork in Chiapas, Mexico, she focused on a particular tree, Miconia affinis, which is pollinated by an unusual method known as buzz pollination.

In order to release pollen from its flowers, bees grab hold and vibrate their flight muscles, shaking the pollen free.

According to Jha, non-native species such as Africanized honeybees don't perform buzz pollination, but native bees do.

"So, I thought Miconia, which requires buzz pollination and is common both in forests and on coffee farms, could be a bio-indicator of how well native bees are pollinating native plants," she said.

As she spent time in the field, however, Jha realized that the story of how Miconia trees spread into coffee farms and how their dispersal affects the tree population's genetic diversity begged to be addressed before she proceeded with the pollen studies.

With guidance from Dick, an assistant professor of ecology and evolutionary biology who studies genetic diversity patterns in tropical tree species, Jha collected and analyzed DNA samples from Miconia trees growing in a network of coffee farms and forest fragments.

Typical of many coffee farms in the area, the three farms in the study were clear-cut and burned in the late 1930s and immediately replanted with coffee bushes and canopy tree species, including nitrogen-fixing legumes and fruit trees.

This study shows that shade coffee farms, by being hospitable to birds, support widespread dispersal of native trees, in effect connecting patches of surrounding forest.

In addition, shade coffee farms may serve as reservoirs for future forest regeneration, as the farms typically fall out of production in less than a century.

"Given that potential - as well as their roles in connecting habitat patches, preserving genetic diversity and sheltering native wildlife - it is important to encourage this traditional style of agriculture," Jha said.

"It's more essential than ever to pay attention to the ecological benefits shade coffee farms provide," she added. (ANI)