Flora and Vegetation:

Contrary to other Islands of Polynesian, the flora of Rapa Nui it doesn't present great diversity and endemism, at the moment its vegetation can be characterized how a dry savanna with an abundant herbaceous stratum, with some associations exotic forest. This situation is confirmed by the descriptions of the first navigators who point out the poverty of its flora and the nonexistence of forests.

However, the paleobotanic and archaeological studies indicates us that the vegetation of Rapa Nui it has not always been as we know it at the present time, in the last 38 thousand years big variations have existed so much in the composition of the flora like in its abundance and distribution. One of the main conclusions of these investigations, is especially the existence in prehistoric times of extensive forest associations, around of the main insular volcanos.

Before the arrival of the polynesian settlers, the changes in the vegetation were probably influenced by the climatic changes from the end of the Pleistocenic until the Holocenic. Another factor that should be mentioned is the episodes of intense volcanism that it supported the island 10 to 12 thousand years ago, testimony of these they are the mark of trunks of kind of an extinct Palm, found in the flows of lavas that formed the coastal line in several sectors of the island.
Without a doubt, the biggest changes register with the arrival from the man to the Island in the century V B.C. The Colonists introduce diverse vegetable species as yam or uhi (Discorea Alata), Taro (Colocasia Esculenta), bananas or Maika (Musa Sp.), Sweet Potatoes kumara (Ipomoea Batatas), cane of sugar or Toa (Sacharum Officinarum) and Ti (Cordyline Terminalis), pumpkin or Hue, Ipu Kaha (Lagenaria Siceraria), Mahute (Broussonettia Papyrífera), mako'i (Thespesia Populnea), and marikuru (Sapindus Saponaria).

Parallelly the pruning agriculture begins and it touches that seemingly was a decisive factor in the extinction of the endemic Palm of the Island (Paschalococos Disperta), and probably of other woody species as the Sandalwood (Santalum Sp.), on these species they are only vague references in Legends and old songs. On the other hand, the introduction of invasive species as the Rat Polynesian is believed that they also contributed to the extinction of species, is necessary to remember that these rodents, without more depredadores than the man could multiply feeding of the coconuts of the Rapa Nui Palm and to diminish their reproduction possibilities.

Traditionally we associates the extinction from the Forests to the exploitation of forest resources for the trasport of Moai and the Construction of Ahu. Indeed the execution of these works should demand an enormous quantity of trunks of Palm and strings, elaborated starting from the bark of Hau Hau (Triumffeta semitriloba).

Toward the Century XVIII, wide sectors of the island meet with a scarce herbaceous covering and some bosquetes relictuales survivors is presented, especially of Toromiro (Sophora Toromiro), Mako´i (Thespesia Populnea) and Hau Hau (Triumffetta Semitriloba). this way the first European navigators that visit her verify their poverty and the begins "mistery" on the transfer of the megalithic statues.

In the following century new vegetable species are introduced, especially of European origin and the intensive upbringing of Livestock begins, especially sheeps, that will mean the blow of grace to the spices endemic survivors, taking place the extinction of the Sandalwood toward 1880, that of the Toromiro in 1956, and at the present moment the Hau Hau is about to disappear, since only they are two specimens inside the crater of the volcano Rano Kau.

The introduced species dominate the current landscape of the island, highlighting among the woody several species of Eucalyptuses, Melia and Guavas, among the grass introduced as Here Hoi (Sporobolus africanus), the Toroko (Sorghum halepense), also in recent years the Mauku Piro (Melinnis Minutiflora) has spread for the interior area, invasive species that generates a high temperature, to be burn being for its oily content, with the rising damage to the soil.