Herbarium Digital Library

Batanes Island

Category: Critical Plant Sites
Date Posted: 2005-12-27

Batanes is the smallest province in the Philippines composed of 3 main islands namely Batan, Sabtang, and Itbayat. It has an approximate land area of only about 20,928 hectares and is in the northernmost tip of the country.

The Islands experience a very pronounced maximum wet season yielding a high average annual rainfall greater than the country's average. There is no dry season in the area. The average annual temperature of the province is 25.7?C with the coolest months from December to February.

There are 6 distinct habitat types in the Islands, namely: grassland (pasture land) at the hills, lowland evergreen rainforest, mid-montane forest, grassland at the mountain summit, beach forest, and second growth forest.

The primary forest areas in Itbayat occupy a smaller area compared to Batan Islands. Secondary forests are found in the abandoned kaingin clearings. Mt. Riposet on the southwestern part of the island is a rolling grassland and is totally cleared of trees. Mt. Sta. Rosa, on the northern part of the islands is almost without forest cover except on the western slope. The island is predominantly grassland and cultivated areas. Noteworthy are the wild plants called arius (Podocarpus costalis and Podocarpus polystachyus) which abound along the coastal areas of the island. These plants, being highly ornamental are transplanted to Batan Island, Luzon and even to Taiwan.

Sabtang Island is almost entirely bare of trees except on the steep slopes of the serrated ridges. A big portion of the island is covered with various species of grasses such as Imperatacylindrica, Saccharum spontaneum, Themeda species, etc. The rest of the area is cultivated mainly using the kaingin system of farming. On the rolling hills at the western part of the island are patches of the endemic palm, Phoenis hanceana variety philippinesis. Ibahos and Dequey islands are mainly rolling grasslands. Some pandans and palm trees are found along the coastal areas. Small patches of forests may be found in the islands of Diogo, Mabudis, Maysanga and Siaya. The rest of the islets are almost devoid of trees.

The vegetation island in Mt Iraya, Batan Island, may be classified into 3 distinct types namely: the lowland evergreen rainforest (200-500m), lower montane rainforest (500-800m) and grassland (800-1008m). At the eastern slope of Mt. Iraya, at an altitude of about 50-100m, is a dense thicket composed of species characteristic of regenerating or disturbed primary forest. The presence of a dense mat of the giant reed, Miscanthus sinensis variety condensatus, at the upper part of Mt. Iraya above 800m suggests that a relatively recent eruption of the volcano has occurred.

Mt. Matarem, also in Batan Island, is a smaller mountain with fringes. Communal forests are also found in pockets and ravines.

Despite it proximity, the flora of Batanes is not so closely related with that of Formosa. This may be explained by the fact that the connections between the Philippines and Formosa and southeastern Asia were broken in the early Teritary, the break being persistent since that period. There are about 37 species of flowering plants which are found exclusively in Formosa and the Philippines. The list includes Bergia serrata, Illigera luzonensis, Gynura elliptica, Gaultheria cumingiana, Isanthera discolor, CAllicarpa formosana, Scutellaria luzonica, Ainslaea reflexa, Dicksonia smithii, and Aglaia formosana. Some of these species may have been disseminated by wind or by birds.

The Batanes Island Group is now included in the National Integrated Protected Area System under the IUCN category Protected Seascapes and Landscapes. Though this protected area category does not ensure the abatement of (public) forest land conversion, it would nevertheless promote sustainable growth or development which would benefit the local inhabitants as a whole through strict monitoring of illegal activities by the law enforcers. Effective management of the protected area may however, be hampered because of its geographic isolation and inadequate transportation and communication facilities.

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