Clearing wooded "shade" plantations for open farmland doesn't just hurt biodiversity, it may also make it more difficult to control pests, and lead to crop losses, according to a new study -- making the higher price of shade-grown coffee and other products a small one to pay.
Growing coffee, cacao beans, cardamom, and yerba mate underneath forest trees rather than converting such "agroforests" into farmland has long been recognized as beneficial for birds, tree biodiversity, and future coffee crops. But the recent findings add a potential economic argument for shade-grown products to the environmental one.
The study of 6,093 tropical bird species by Çağan H. Şekercioğlu, an assistant professor of biology at the University of Utah, found that agroforests are better for bird biodiversity in the tropics than open farms and suggest they also allow birds to provide a higher level of "ecosystem services" to people.
Limiting Crop Losses
"As you go to more and more open agriculture, you lose some bird groups that provide important ecosystem services like insect control [insect eaters], seed dispersal [fruit eaters], and pollination [nectar eaters], while you get higher numbers of granivores [seed and grain eaters] that actually can be crop pests," Şekercioğlu said in a University of Utah press release about the study, published this month in the Journal of Ornithology.
According to Şekercioğlu's research, only one group of birds significantly benefited from increases in open agricultural areas: grain- and seed-eaters that in some cases can be "major agricultural pests," he said. "That's another reason for encouraging agroforests. In completely open agricultural systems, you have more seed-eating birds that can cause significant crop losses."