The Malaysian region is the botanical unit which links to Asia through the Malay Peninsula and Philippines, to the islands of the Pacific, by the Bismarck and Salmon islands, and to Australia through the island of New Guinea.
Various authors have divided it's flora in oriental and occidental, including Timor in either groups. With the prevalence of Zollinger's suggestion, Timor was definitively included in the division constituted by the Malay Peninsula, Sumatra, Java, Bali, Lombok, Sumbawa, Sumba, Flores and the island of Borneo, while the Celebes and the island of New Guinea form the oriental group.
Since the beginning of the 19th century, when Gaudichaud became the first botanic ever to aport Díli, East Timor's spontaneous specimens and associations have interested renowned biologists including A. Russel Wallace to whom is owed the preliminary works of the botanical distribution in the Malay Archipelago, and Henry O. Forbes who presented the most valuous contribution for the acknowledgment of the territory's flora. The more recent studies date from 1950, by Ruy Cinatti, whom we have particularly followed. As almost half a century has passed by, the numbers relative to the distribution of the different types of forest aren't to be considered without some reserves, but certainly remain approximate. Besides that, says the above agronomist that the botanical study of East Timor isn't complete. For instance, we haven't information about Ataúro (Pulo-Cambing).
Although vegetation is abundant in East Timor, forestal formations fail perform an important role in the economy. Far from showing the luxurious feature of Sumatra, Java, Bali or island of New Guinea, the primary forest is poorly represented, and frequently in a mixed regime with the secondary forest, after being destroyed through the ages for the necessities of an itinerary agricultural regime. The geological constitution of the territory, mainly of sedimentary rocks, less favorable vegetal development is also appointed as a cause, and certainly the exposure of the denuded lands that man left behind to the calcinating sun had a nasty effect in it's fertility. As it happens, the successive Portuguese administrations didn't take necessary measures to protect the forest.
H. L. Silva (engineer of agronomy) thinks that <<even in the regions with low rainfall, long dry period, temperature and humidity more or less high, the original vegetation, preceding the destruction imposed by the necessities of an itinerary agriculture, should have been the xerophytic forest. In times, Timor should have been an immense forest in accordance to it's ambiental conditions, which nowadays aren't the determinant of the herbaceous revestement which isn't original in Timor, but a regressive stage of spontaneous vegetation>>.
The primary forest is that in which natural groves have flourished since remote times untouched by man. It is reduced to an area of approximately 220 000 acres, that is 1% of the territory! Due to more favorable micro-climatic and edaphic conditions, only in the south coast and mountainous zone are there dense forests of comparative importance to be found.
Cinatti divides this primary forest into five sub-types: mangrove, littoranean, of the low regions, medium, and mountainous. With an aspect more or less uniform in the Indonesia archipelago, the first two will be treated separately for they have very defined habitats.
The mangrove. It occupies a small area, more or less 7 500 acres, because of the territory's coastal configuration which, diversely to other islands of the Indonesian archipelago, hasn't salient contours. The sea is rough, mainly in the south coast and the water courses don't work out in dilated estuaries, while the mangrove appears in sites defined by inlets where the waters become restful. The habitat is very determined: the littoral, between the limits influenced by salty and brackish waters, growing nowhere else.
It's in the north coast, where the sea is calmer that the mangrove is more seen, in areas like Metinaro, Tibar and Maubara, whereas in the south coast it's expansion doesn't go beyond the mouth of the streams, and marshy or swampy terrains. Besides, the groves can be constituted by a single specie. Almost all belong to families not closely related, but the characters of adaptation to the environment are alike: leathery and hairless whole leaves, roots with pneumatophorus, trunks very shored by a complex rooting, fruits adapted to the dissemination by the currents, and seeds possible to germinate out of it's natural environment (Rhizophora conjugata, Bruguiera parvifolia).
If the physiography is suitable, the diverse species will associate regularly in lines parallel to the margins (affected by the tides), obeying to an edaphic transition in accordance to the salinity of the water that floods the soil and this one's physic-chemical characteristics, being practically independent of the pluvial regime.
In the salty waters where the terrains are submersed permanent or temporarily, Sonneratia alba and Bruguiera parvifolia appear in the sandy sediment, Rhizophora conjugata and still Bruguiera in the mire, and again in the coraligenous sediment with the Excoecaria Agallocha.
Where the salty waters are stagnant with the terrains inundated temporarily, Rhizophora conjugata and Avicennia marina grow in the mire, and this last specie, the Aegiceras corniculatum, Acanthus ilicifolius, Lumnitzera racemosa in the dark argilous more or less flooded soils, but where they are rarely inundated, Heritiera litoralis and Acanthus ilicifolius are more seen.
Finally, in the brackish waters, where the terrains are inundated in the rainy period, or along the margins of the streams, from dark argilous more or less muddy lands rise Avicennia marina, Achrosticum aureum, Xylocarpus Granatum, Corypha utan, Pandanus odoratissimus, Cycas circinalis, Dolichandrone spathacea and Melaleuca Leucadendron. The last two species belong already to the primary and secondary forests of the low regions respectively.
In Cinatti's dicription, the primary florest of the mangrove appears to sight as a massif of intense greenery that contrasts singularly with the sea blue and the golden green of the cliffs from the north coast. The inside ambient is gloomy, almost sepulchral. The trees rise up to 20 or 30 m (Rhizophora conjugata), supported by an inextricable valance of thick radicular prolongments inserted in the trunks at different heights.
The landscape is monotonous though the view of a serried horizon difficult to penetrate and it's quietude may be appealing. One can hear the air bubbles that continuously jet to the surface of the inundated land. Crustaceans, that stick on the aerial roots, and mosquitoes are abundant, but not a bird can be seen.
In the sandy terrains, more proximate to the coast, the roots of trees are provided with pneumatophorus (Sonneratia alba) like nails across planks, while pure colonies of Avicennia marina grow aside vast extensions of saltpetred soils which at distance resemble snow fields.
In agricultural terms, the mangrove area is of no interest. For the industrial though, it's a source of revenue. The wood has much quality, and from the bark valuous tannin substances are extracted.
Littoral forest. The area occupied is narrow, only in the south coast has it some agricultural interest. Not complicated as the vegetation of the interior nor acquiring the density common to certain valleys and margins of water courses, it's flora is relatively poor in genera and species. A main feature is their adaptation to the dissemination of the maritime currents, which are responsible for it's propagation, which covers an extense strip along the littoral.
Physionomically comprising various forms, from high statured trees to herbaceous plants, it's distribution is conditioned by the quantity of precipitation, influence of the prominent winds, presence of water courses and above all, by the degree of atmospheric humidity. Alike the mangrove, the florest of the littoral of East Timor doesn't differ from the remaining islands of the Indonesian archipelago.
In the south coast, under climatic type D (more humid), it reaches the climax in quantity of species, density of the agroupments and covering. There, formations of Calophyllum, Hernandia, Heritiera, Cerbera, Terminalia, Barringtonia, etc. spread in waves of greenery onto the beaches partially covered by the association Spinifex littoreus--Ipomoea pes-caprae.
In other places however, the sandy expanses are bordered with narrow strips of Casuarina composing almost pure colonies, with which Pandanus are occasionally associated. Yet again, where the sandy beaches give way to coral terraces, a string of Hibiscus tiliaceus and of Thespesia populnea divides the barren ground from that where appear floristic complexes, often giving the appearance of a typical mixed forest. In the proximity's of little streams may be seen patches covered with palms with Corypha utan in the more flooded soils and Borassus flabellifer in the dryer. Man's activity is witnessed by plantations of Cocos nucifera that pend their branches over the water, reproducing the classic landscape of the south seas.
These aspects are to be found from Bê Açu in the circumscription of Viqueque, through Aliambata, to the easternmost of the island.
In the north littoral, due to climate, predominantly influenced by type F (considerably dry), and to the more accidented relief, the littoral primary forest suffers in variety and vigour. From Maubara to Lautém it becomes less often, appearing either normal, else disappearing altogether and replaced by grassy lands here and there invaded by pioneer representatives of the secondary forest and savanna such as Eucalyptus alba, Zizyphus mauritania, Tamarindus indica, and even indicators of dry climates such as Opuntia, Aloes, and Euphorbia species.
Mixed forest. In the low and medium regions it can be evergreen (rain forest) or deciduous (monsoon forest). Local differences of the soil, exposition, drainage, the abundance and distribution of precipitation favour this variation as well as the subjacent geological formations: the vegetation in sedimentary terrains is distinct from that found in the volcanic, even though that difference isn't apparent in regions submitted to a climatic regime of more or less consecutive rainfall. The description of a primary forest of the low regions therefore differs from place to place on the contrary of the mangrove or littoral forest colonies. The trees are of great stature but in the rocky slopes, they are generally small even with much rainfall.
In the mountainous regions, vegetation is always evergreen.
Present at all altitudes, the perennial leave forest develops preferably under type C and D climatic areas, wherever rainfall is more or less permanent as to satisfy it's necessities. In the low and medium regions predominate the species from the genera Eugenia, Intsia, Elaeocarpus, Canarium, Dysoxylum, Ficus, Litsea, Sarcocephalus, Terminalia, Parinarium, Prometia, and in the mountainous Podocarpus imbricata, Casuarina Junghuhniana, Pygeum sp., Vaccinium sp., Palaquium sp., Planchonela sp., and Eucalyptus sp. (designated before as E. obliqua or E. Decaisneana), endemic specie that above 800 m covers almost all the elevations of East Timor, representing a new specie in the opinion of Cinatti.
The deciduous primary florest is present in the low and medium height regions influenced by climatic types E and F, and therefore along all the north coast up to a height of 600 m. It is composed dominantly by the genera Schleichera (S Oleosa) and Pterocarpus (P. indicus) to which is associated Acacia, Vitex, Corypha, Wrigthia, Pterospermum (P. acerifolium), Sterculia (S. foetida), Zizyphus and Bauhinia.
The evergreen forest of the low-lying lands reaches most perfect ecological form in certain regions of the south coast, specially at southeast where predominates a climate type C. It's limits is defined by the covering, soil and fringe. The trunks of the trees ramify at variable heights but always elevate, forming a very thick covering with the fringes enclosing the interior through numerous creepers. Though apparent, the initial impression is of impenetrability.
The covering and the fringe are therefore related through the conditions that prevail in the exterior, which are totally diverse from the interior. Herein the sieved daylight acquires crepuscular tones, the rain and wind decrease in intensity to the point of becoming senseless. While the outside is susceptible to extreme climatic conditions -- wind and light breeze, high temperatures and sudden drops, humidity and drought -- the interior forms a natural hot-house.
The struggle for existence among individuals and species becomes violent, what suggests an organism in which the unities constantly try to maintain a state of equilibrium. When it is interrupted, like in a case of some old branch which's fall opens a breach on the covering, the vegetation reacts immediately.
The sub-arboreal vegetation (herbaceous plants, shrubs and small trees) sprouts promptly before the opportunity to develop now that sunlight and rain penetrate without obstacles. But soon the opening is mended by creepers that enlace from the covering to the lower trees and so all the occasional vegetation decays except for some trees which will restore the provisional covering.
The high and constant internal humidity propitiates the ecological residence for the hygrophytic species, but even though the soil is rich in humus, the absence of sunlight stresses sub-arboreal development: only small communities of plants such as Araceae and ferns subsist in spots with some clarity, while shrubs are rickety and moss-revested, and small trees slender and erect.
Above those, two or three storey foliage trees with higher fustic follow up until the final covering. In between the trunks, completely covered by creepers and epiphytes, grow Pandanus and rattans, which in certain places make the forest almost impenetrable. Still there's the over-sized trees, with 1 to 3 m of diameter and exposed to different climatic conditions from all the others. The sun, wind and rain act directly on their tops, but they cannot be classified as xerophytic for their roots find the best conditions in the hygrophytic environment. All dominant trees of the low-lying rain florest is mesophytic, being xerophytic the epiphytes that develop on the tree-tops and are unable to capture water other than the received directly from the atmosphere through rainfall or evaporation.
The vegetation of the medium and mountainous regions differs considerably from the low-lying lands, increasingly with altitude as the fog station above the ridges and immediate slopes. Separated in the mesophytic florest, the xerophytic epiphytes and the hygrophytes tend to mix as the florest looses density, progressively inverting the initial places: the hygrophytes start covering to the tree-tops and the xerophytes to develop near the ground. Once reached the surrounding limits of this forest, small shrubs or islands of forest vegetation dispose irregularly, according to exterior conditions.
The deciduous florest, predominant in the north coast where climate is dryer (under types E and F), proliferates in all territory, except for the mountainous regions. Due to topographic conditions, edaphic, and micro-climatic, this formation is present in accentuated mixed regime with the evergreen forest -- with preponderance of the deciduous -- and also with components of the secondary forest, in a distribution somewhat independent of the climatic regions in which they prevail. Some species of deciduous foliage characteristic of type E and F can even be perennial in type D regions like, for instance, Gossampinus heptophylla and Gyrocarpus americanus.
In this sense the proximity of the streams and superficial sheets of water perform an important role. In fact, as some species distribute naturally around the more or less swampy terrains or along the streams, similar communities happen to occur at different heights.
Reasons of inaccessibility and low population density propitiate the deciduous florest to appear with it's most equilibrated physionomy in the enclave of Ocussi-Ambeno, at the region of Citrana from the sea level to 300 m high. The species of Pterocarpus are the most represented there. Following Cinatti's distribution -- which he adverts to be peccable because too schematic --, in the littoral to the Pterocarpus associate the Gyrocarpus americanus in the dry and accidented areas, and the Corypha utan in the laky or near water courses. Around 100 m high, this palm takes a bushy shape and is gradually replaced by Homalium tomentosum.In the higher areas xerophytic epiphytes -- orchids and Asplenium nidus -- stick to the trunks of the Pterocarpus.
It's also in the deciduous forest that herbaceous plants find most adequate conditions to develop.
From altitudes between 1500 -- 1800 m, the mountainous regions, changes that climate operates on the florest become noticeable. Evident in the smoother slopes, it actuates impressively in the ridges and other saliences. All over the soil and skeleton of the trees the space is occupied profusely by mosses, lichens, orchids, ant other epiphytes. In the description of Cinatti, the revigorous influence of the climate adds to the idea of a pleasant walk on a smooth carpet, which in reality leaves one's feet soaked. The moss revestment is saturated of water, and the spectacle is always the same, either in the florest of Eucalyptus Decaisneana, or in which predominates Podocarpus imbricata. The ambient transports the imagination to times previous to the appearance of Man. The terrains are permanently humid because of the abundant rainfall -- proper of the mountainous regions, under climate type C -- and the frequency, almost diary, of fogs (which have however a restricting effect in modifications current in the mountainous forest).
The trunk and ramifications of Eucalyptus Decaisneana have apparently twice the thickness and through the leaves oftenly pend threads of moss. Among the forest, the atmosphere pleasantly fresh becomes chilly due not as much to the temperature of the air as to the uninterruptive fall of water drops exuded from the covering.
Upwards the mosses get to dominate, giving the characteristic tone to the landscape, yet diminishing in the higher altitudes, between 2700 -- 2900 m, where the winds run freely, provoking on the trees abnormal shapes. Typical genera of temperate climates usually take place such as inodour violets, brambles (Rubus rosifolins), buttercups (Ranunculus sp.), Vaccinium timorensis (a tree upon which vine creeps), gentians and others that in the phylogenetic and physionomic point of view transport us to distant lands. Based on meteorological reports. L. S. Gibbs filiates the presence of the above species in there essences having been transported from the Himalayas, across the higher peaks of the Malay Archipelago by the prominent winds of the NW monsoon. It's also in the mountainous florest that can be recognized common species to the Australian flora of the higher latitudes, which in remote times -- and possibly still nowadays -- were brought by the cyclonic movements frequent in the east coast of Australia and in the Timor Sea during the rainy period.
Besides the Eucalyptus decaisneana the Styphelia oborata may be found associated among others of the higher latitudes from both hemispheres.
Tufts of bamboo and Pandanus appear occasionally proximate to the biological limits, in the edge revested with pastures or inextricable entanglement of sub-arbustive vegetation difficult to go through.
In Timor, as common to the hot countries that make the principal alimentary cultures rely on the rainfall -- specifically in the regions with a long dry period, such as in the case of the north coast -- the primary forest kept on succumbing for the necessities of an itinerary agricultural regime which has in annual burnings it's best "bulldozer". And now it is reduced to little over 1% of the East-Timorese territories. Wasted the florest, the kitchen-gardens will occupate the land only during a couple of years because as soon as fertility declines or the invasion of unwanted herbs make it too difficult to work on and success of the crop becomes aleatory, this ground is abandoned to fallow for sometimes thirty years. The peasant chooses another place to restart his kitchen-garden, preferably in the florest lands as they're more fruitful though in fact don't require much less labour. What happens is that the millenary experience has taught the natives that the destruction of the unwanted herbs provokes quicker lost of fertility. Therefore, generally where the population isn't too dense, the land is abandoned without degradation being completely unrecoverable. The succession of a secondary forest is then possible, which through everywhere will cover the fallow lands. It adds more or less 18.5 million acres, representing 98.5 % of East Timor, and is sprinkled with spots of savannas and pastures (265 thousand acres: 1.5 %), and persisting representatives of the primary florest.
This secondary florest can be present in three essential aspects: from the
herbaceous, to the tufts of bamboo with colonies of casuarinas and eucalyptuses
(E. alba), and to the secondary florest in strict sense, which includes dense
formations of shrubs, small trees, and creepers surrounding representations of
the primary florest, both outjutting from a herbaceous mantle sometimes
(To be continued)