La Trinidad, Benguet – Any flora or fauna (plant or animal) inserted into a completely unfamiliar environment through human act, whether accidentally or intentionally, is considered invasive.
Many will argue that non-native species are not an issue, they say these have successfully integrated in the provinces, cities and places like Cordillera Administrative Region (CAR), Region 1 as well as in all places in the country.
But that is exactly the main issue. Their having successfully intermingled in new environment is pointed to by environmental specialists as one major reason in the despoiling of native species and natural habitat.
Infestation of certain species not native to highland and lowland environments is determinedly creeping in relentlessly, and specialists warn time will arrive when native species are forced to surrender their grounds from encroachment of non-native species.
Agro-forestry experts in Cordillera Administrative Region (CAR) who graduated from the region’s premier agricultural school, the government’s Benguet State University (BSU) bared that “nothing is gained for native settings being overrun by alien species.”
Once they are established, they are difficult – some impossible – to remove. And the damage to indigenous environment systems can be significant and costly in terms of biodiversity, livelihood and economy.
They pointed to an incident well known in the Philippine countryside when in the 1970’s, the golden apple snail was introduced into farmlands supposedly as a source of food and income to farmers.
The golden apple snail is native to South America but was introduced via Taiwan. Even the government touted it as an answer to protein needs for Filipino households, only for the snails to become later a became a farmland scourge, attacking rice plants, increased in a rates and destroying vast tracts of crops.
In Tabuk, Kalinga, during that time, farmers had to rely heavily on pesticide use to eradicate the snail, as did other farmers in the country, the experts recalled.
Since its introduction it was revealed by experts that loss of aquatic crops in the Philippines by destruction of the golden snails ran from an estimated US dollar 1,200 million per annum, without taking into account non-crop damage to human health and Philippine natural ecosystems.
Introduction of a non-native species can result to extinction of native plants and animals, degrading the immediate environment where it’s introduced, competing with native organisms and altering habitat.
Invasive Alien Species (IAS) as these agro-foresters technically call it, is seen as also one major threat to CAR and Region 1 biodiversity, after habitat destruction.
One agro-forester, Dobbs Wallang, from Benguet, believes, “There’s an urgent need to develop effective biosecurity measures to prevent the IAS problem from becoming serious in our region.”
These agro-foresters recommended, but not solely restricted to, increasing number and scale of efforts to eradicate any invasive species, integrate such efforts into protected area management plans, set up and increase funds for eradication, institutionalize invasive species programs within different government offices, engage civil society/relevant sectors and invest in collecting and sharing IAS information.
Another agro-forester, Alvin Pinasi, from the lowlands, holds the view that, “Invasive species problem is growing because of human invasion into remaining forest habitats, increased movement of goods and people and the collective effects of climate change.”
Great risk for biological invasion affects emerging economies where some of the poor communities and richest biodiversity areas like the Cordillera hinterlands, are, in the thinking of the agro-foresters.
Most important for CAR, and generally for other regional priorities, is to start with prevention since invasive species are the leading cause of extinction of endemic species and resulting to degradation on the resilience of insular ecosystems against climate change, the agro-foresters explained.
Many aren’t aware, the agro-foresters emphasized, about different tree species usually seen growing in the countryside have been listed as invasive. These include the large-leaf mahogany, paper mulberry, Siam weed or hagonoy, coronitas or baho-baho, ipil-ipil, Chines creeper, ymane or Gmelina, acasia, water fern, water hyacinth, among others.
Mahogany, for example, is a major invasive species that when planted in large numbers is capable of creating a “green desert” since their leaves when shed are hardly eaten by animals and form a thick mat on the soil floor, preventing other seeds from direct contact with earth to germinate.
Mahogany leaves are rich in tannin, an acidic substance that retards growth of other plants, or what the agro-foresters explained as allelopathy – the suppression of growth of a plant as a result of a toxin released by another plant.
It was pointed that most Cordillerans and lowlanders aren’t aware that within their homes, non-native plants have invaded their surroundings because of the ornamental plants they care and tend but which are not indigenous to the regions.
One of these is the favorite potted mahogany and sold to others for planting in their backyards, creating a chain of invasive species to other homes.
Another is the African tulip tree, some grown in Baguio City. African tulip trees can easily crowd out native species like the Benguet pine tree and are extremely difficult to remove as they can grow back from root fragments and dispersed seeds.
Another grown in Baguio City is the jacaranda tree which can form thickets of seedlings that can overwhelm other vegetation.
Another agro-forester, Henry Borreo, who traces part of the blood running in his veins with the Agta tribe of the Sierra Madre Mountain Range, frowns on planting exotic trees, explaining, “There is a law protecting and nurturing endemic trees. Our native trees grow better and fully adapted to local conditions. They have higher resistance to pests and are resilient.”
They raised concern about what they think as “excessive use” of exotic trees (like Gmelina and mahogany) over indigenous varieties in the country’s greening programs.
All in CAR, Region and in the Philippines, people have not fully understood the IAS problem, but they experience it daily when trying to get rid of a pest in their homes, like the like the American cockroach, an ubiquitous house pest impossible to eradicate.
In highland farming towns, farmers have to spend continuously to control the invasive potato cyst nematode, accidentally introduced in Benguet when potato planting materials were imported in the past.
They also wage constant battle against the Spiraling Whitefly that affects vegetables and ornamentals. This fly was accidentally introduced in the Philippines in the 1970’s when the ornamental plant kalanchoe became a household rave.
Presently, Benguet cut-flowers farmers fight a see-saw conflict against the leaf miner, which was introduced in the uplands following importation of chrysanthemum planting materials. It also attacks potato and other ornamental plants.
In border parts of Benguet with close proximity with La Union, ipil-ipil planted in these places have been noticed attacked by the jumping plant lice, non-native species.
All over the country has seen the march of millions of red fire ants that have already invaded all communities, attacking native ants and dislodging these from their lairs. These fire ants, with fiery and painful stings, are native to South America.
Another ant specie, the big-headed ant has become a pest to agriculture because it is host to insects that reduce crop productivity. It is a danger to native ants since it displaces them. Big-headed ants come from the US and Australia and considered also one of the most successful species invaders, like the red ant, worldwide.
Invasive tree species that harbor pests are Gmelina, host to the pest Ozala minor, a moth; Acasia tree, host to Anoplophora luciphor, a genus of beetles capable of attacking and killing native trees by boring into these.
Other listed invasive trees like Eucalyptus, is host to termite species, the mahogany carries with it a moth whose larvae is capable of attacking native plants like coffee trees by boring into the stems or branches.
Importation continues of invasive fish species slipping past customs and ending up in commercial aquarium shops that sell these to buyers who, in turn, after getting tired of these alien fishes as pets, just dump them into waterways. These alien fishes become predators to native fishes.
It’s the recommendation of the environmental specialists that crop selection as well as choosing choice ornamental plants and hedge be considered by home planters for sustainable environment condition and biodiversity.
One cannot just introduce a lovely-looking plant or lovely-looking fish at home later to be discovered these being invasive and destructive. This isn’t just an issue of enforcement. People must be educated, the experts said.
Presently, it was estimated that about 138 IAS are already on Philippine settings.
On the government front, Environment Secretary Roy Cimatu has called on experts in the Asia-Pacific region to work cooperatively for solutions that will address IAS. “I stand firm in promoting convergence for a sustainable, region-wide management of IAS,” Cimatu emphasized. – Bony A. Bengwayan