Included here is the Philippine Achipelago and the Calamian Islands, Basilan Island, the northernmost island in the Sulu Achipelago, the Babuyan Islands and the Batan Islands.

Philippinean Montane Forest

Above the dipterocarp forest from about the 600 m contour the forests are much less dense and the number of tree stories are reduced to two. The canopy height varies with altitude but reaches about 18 m at an elevation of about 700 m, while the lower story varies from between 6-12 m. However, it is difficult to define these forests in terms of dominant species, but fairly prevalent first story species include Neonauclea calycina, Quercus soleriana, various species of Ficus and the endemic Palaquium philippense (Sapotaceae) and Weinmannia luzoniensis (Cunoniaceae). The second story is composed of a multitude of species, some of which like the endemic Sauravia luzoniensis (Sauraviaceae) rarely reach more than about 6 m in height. Other endemic small trees include Arthrophyllum pulgarense (Araliaceae), Symplocos whitfordii (Symplocaceae) and Viburnum cornutidens (Caprifoliaceae). Palms are much less frequent and mostly represented by scattered specimens of Pinanya barnesii. Tree ferns, on the other hand, become far more abundant and include endemic species like Cyathea caudata, C. heterochlamydea, C. robinsonii and C. zamboanyana (Cyatheaceae). Dicotyledonous vines are also less prominent with monocots like climbing palms (rattans) and species of the genus Freycinetia (Pandanaceae) making up most of the climbing flora, although the woody, endemic vine Kadura philippinensis (Schisandraceae) may be encountered.  The most conspicuous change compared to the lowland forests is the increased epiphytic flora, but again these are mostly confined to the crowns of tall trees. For example, there are several species of the fern genus Aglaomorpha including the spectacular endemic Aglaomorpha splendens (Polypodiaceae) with its large pinnate leaves. The trunks of trees usually only support a sparse covering of mosses and other epiphytic species, and it is the bark of trees that is prominent in giving character to the appearance of these forests, especially at lower altitudes. Other endemic species include Sphaerostephanos lobatus (Thelypteridaceae) and Teratophyllum luzonicum (Lomariopsidaceae).

Philippinean Montane Mossy Forest

From an altitude of about 1200 m, such as mountain summits like the top of Mount Maguiling, the cloud belt starts shrouding these zones in mist for long periods. The high relative humidity and low evaporation rates is responsible for many of the features of these forests and in many ways they are of more interest than those at lower elevations. One of the most obvious features is the abundance of epiphytic mosses. In places these may be several centimeters thick and can reach 30 cm in length. In addition to mosses there are many filmy ferns and small species of the clubmoss Selaginella such as the endemic Selaginella maquiliense (Selaginaceae). There is usually a single story of low trees with a canopy height of about 10 m. Many of the trees have a tendency to send out aerial roots often causing them to have fantastic shapes. Species of Astronia, particularly A. lagunensis, and trees ferns (Cyathea) are the dominant tree taxa in terms of numbers of species. Tree ferns are very abundant growing luxuriantly among other trees and giving these forests a primordial appearance, and many of these, like Cyathea edanoi, C. ferruginea, C. fuliginosa and C. philippinensis (Cyatheaceae), are endemic. Other endemic trees include Aquilaria apiculata (Thymelaeaceae), Clethra tomentella (Clethraceae), Diplycosia luzonica (Ericaceae), Guioa myriadenia (Sapindaceae), Matthaea pubescens (Monimiaceae), Microtropis curvanii (Celastraceae), Podocarpus lophatus (Podocarpaceae), Prunus subglabra (Rosaceae), Schuumansia vidalii (family?) and Vaccinium barandanum (Ericaceae). Shrubs are also frequently encountered with many endemic species of the Ericaceae such as Dimorphanthera mindanaensis, Rhododendron mindanaense and Vaccinium halconense. Other endemic shrubs include Daphne luzonica (Thymelaeaceae), Daphniphyllum parvifolium (Daphniphyllaceae) and Gomphandra flavicarpa (Icacinaceae). In addition to terrestrial shrubs there are also many epiphytic species, which are again dominated by endemic species of the Ericaceae such as Costera loheri, Diplycosia apoensis, Rhododendron leytense and Vaccinium perrigidum. Vines, both epiphytic and terrestrial, are fairly conspicuous but represented by comparatively few species. Possibly the most frequent are species of Freycinetia particularly Freycinetia williamsii. Where trees send out large numbers of aerial roots and the crowns are overgrown with vines and epiphytes it can be very dark at ground level and devoid of herbaceous species, but where light penetrates fairly dense herbaceous layers can develop. The most conspicuous large herb is Strobilanthes pluriformis, while the smaller ones consist largely of ferns (mainly species of Hymenophyllaceae and Polypodiaceae), together with species of Elatostema and Selaginella. Among the endemic herbaceous flora are Plectranthus sparsiflorus (Lamiaceae), Pogostemon philippinensis (Lamiaceae), Trigonotis philippinensis (Boraginaceae) and Viola merrilliana (Violaceae).

Philippinean Pine Forest

These forests reach their best development on the high plateaus of northern Luzon in the so-called ‘Mountain Province’. They range in altitude from about 900 to 1500 m and are characterized mainly by the presence of Pinus insularis (P. kesiya) and P. merkusii.  Associated endemic plants include Pronephrium rubidum (Thelypteridaceae) and the epiphytic fern Selliguea elmeri (Polypodiaceae).

References

Brown, W. H. 1919. Vegetation of Philippine Mountains. Publication No. 13. Department of Agriculture and Natural Resources, Bureau of Science, Manila.

Campbell, D. G. & Hammond, H. D. 1989. Floristic Inventory of Tropical Countries. The New York Botanical Garden.

Hamann, A., Barbon, E. B., Curio, E. & Madulid, D. A. 1999. A botanical inventory of a submontane tropical rainforest on Negros Island, Philippines. Biodiversity and Conservation, 8: 1017-1031.

Langenberger, G., Martin, K. & Sauerborn, J. 2006. Vascular plant species inventory of a Philippine lowland rain forest and its conservation status. Biodiversity and Conservation, 15: 1271-1301.

Lazardo, L. 1957. The Philippine Pine Forest. Tropical Silviculture, 2: 344-366.

Leith, H. & Werger, M. J. A. 1989. Ecosystems of the World 14B - Tropical Rain Forests. Elsevier Scientific Publishing Company.

Pipoly, J. J. & Madulid, D. A. 1998. Composition, structure and species richness of a submontane moist forest on Mt Kinasalapi, Mindanao, Philippines. In: Forest Biodiversity Research, Monitoring and Modeling. Eds. F. Dallmeier and J. A. Comiskey. Man and the Biosphere Series, Volume 40. The Parthenon Publishing Group.

Steenis, C. G. G. J. van. 1957. Outline of the vegetation types in Indonesia and some adjacent regions. Proceedings of the Pacific Scientific Congress, 8: 61-97.