Shriveled seeds
Did the hunting of fruit-eating birds lead to the shriveling of tree seeds? The journal Science asks in its latest issue. This can damage beyond previous estimates, already-stressed tropical rainforests.
Deforestation in Brazil resulted in trees that yielded smaller, frailer seeds. “The story we are documenting… is common in other tropical areas around the world,” explains Spain’s Prof. Pedro Jordano “(That’s) where big mammals and birds are disappearing.” As in the Philippines ?
Jordano and Sao Paulo State University scientists sifted through more than 9,000 forest seeds. They factored in issues like soil fertility to thinning forest cover. Seeds were significantly smaller, they found. They were less likely to regenerate.
“Kung ano ang binhi, siya an bunga,” a Tagalog proverb says. “What the seed is, so is the fruit.” In the parable of “The Sower,” many of the seeds didn’t sprout. Some were “trampled underfoot.” “Birds of the sky” devoured others. Most fell on rocks or thorns and withered.
Loss of birds triggered today’s shrinking seeds, writes BBC’s science reporter Rebecca Morelle. She quotes Jordano: “The main factor was the disappearance of the large frugivore (fruit-eating) species… One of our major surprises was how deforestation influences the evolution of plant traits—all within a few generations.”
Brazilian birds like the “toucan” and “cotinga” have been hunted to near extinction. In the Philippines, 89 birds are endangered. The Philippine eagle is the best known. Also threatened are the Philippine cockatoo, Cebu flowerpecker (dicaeum quadricolor), Visayan wrinkled hornbill, plus amphibians including the panther flying frog.
The Ticao tarictic hornbill and Sulu Bleeding heart are gone for good. “If we don’t preserve our endemic feathered treasures, they’ll just be remembered in stamps,” says ornithologist J.C. Gonzales. Inexplicably, “songbirds exposed to polluted environments sing more,” says a feature on exotic birds in cities. “But they also die early.”
Like Philippine rainforests, Brazil ’s Atlantic timberland “was once home to a vibrant array of plants and animals.” But the launch of sugar and coffee plantations, in the early 19th century, altered the forest cover radically. Today, just 12 percent of Brazil’s original forest remains.
Less than a quarter of Philippine rainforests are left. In 1595, they blanketed 27.5 million hectares. But a logging mafia wrecked that “heirloom.” Log exports topped 11.1 million cubic meters in 1974, then slumped to 841 thousand cubic meters a decade later. They’ve still to recover.
Juan Ponce Enrile’s logging firm chainsaws the last rainforest in Samar. Will tree stumps crown his checkered career? Enrile see-sawed from a fake martial law ambush to People Power hero, jack-knifed into coup plots, then emerged as firm chair of an impeachment process.
Depletion of forests denudes the mind. A Negros and Panay survey discovered that most of schoolchildren have no concept of natural forests. When asked to draw, they depicted neat rows of plantation trees. Some “baby-boomers think molave (Philippine mahogany) is a street sign,” a forester explained.
Until the early ’80s, the word “biodiversity” rarely cropped up even in scientific meetings. It means the complex web of life forms. These coil within a species or system and can unravel. This is richest along the equator: in fishing grounds along Western Pacific coasts and rainforests. Tropical forests cover 6 percent of the earth but contain more than half the world’s plant and animal species.
Biodiversity in a large number of tropical forests, however, is still eroding, says a 36-nation study in Asia, Africa and Latin America. At the rate of today’s depletion, there is concern “whether tropical forests will continue to function as ‘arks’ for biodiversity and natural ecosystem processes.”
William Laurance of James Cook University (Australia) led the study team. It pinpointed hunting as one of the main threats to biodiversity in protected areas. “About 85 percent of these reserves suffered declines in surrounding forest cover in the [past] 20 to 30 years In contrast only 2 percent gained surrounding forest.”
UP students launched in 1910 the first formal reforestation program at Los Baños. In 1917, President Sergio Osmeña opened Cebu ‘s Camp 7 reforestation project. It still exists in a province where forest cover is less than two percent. The key project of his grandson, outgoing Rep. Tomas Osmeña of Cebu City’s south district, is a bare 296-hectare reclaimed plot. South Road Properties is a semi-desert.
Only 30 percent of reforestation projects succeed. “People hardly recognize benefits from protecting the environment.” Connivance sabotaged the program. When the forests go, so does the topsoil which produces food. Over half (52 percent) of the country is eroded.
In the Ateneo University publication: “Forest Faces: Hopes and Regrets in Philippine Forestry,” Peter Walpole writes: “Regeneration is taking place as secondary forests regain their original stature. Cogon (imperata cylindrical) fields, that blanket logged-over areas, shelter a new generation of pioneering seedlings. (This) is a phoenix forest that could restore and regenerate our landscape. There is hope. But it needs a nurturing hand.”
Climate change, however, unleashed three typhoons within three years on Mindanao. In the past, a storm slammed the island once every 17 years or so. That may deny us the time needed to reverse shrunken tree seeds.
