Fernandezian Coastal Vegetation
On Masatierra the soft coastal rocks tend to disintegrate under the force of large breaking waves making it difficult for plant communities to get established, but where vegetation has managed to develop the main species including Lobelia alata var. rupicola, Polygonum crinitus, Spergularia confertiflora and the endemic Rea pruinata (Asteraceae). Carpets of the maritime bryophyte Bryum fernandeziana are also a feature. Santa Clara has remnants of coastal scrub dominated by Rea pruinata. Here it is associated with several other endemic species including Dendroseris litoralis (Asteraceae), Chenopodium sanctae-clarae (Chenopodiaceae), Solanum robinsonianum (Solaniaceae) and Wahlenbergia berteroi (Campanulaceae). The accumulations of coastal talus and the hard basaltic rocks of Masafuera provide much better conditions for the establishment of seashore vegetation. Here the main colonists include Libertia formosa, Cyperus eragrostis, Spergularia confertiflora and several endemic species like Erigeron rupicola (Asteraceae) and Spergularia masafuerana (Caryophyllaceae). Several ferns including the endemic Pellaea chilensis (Pteridaceae) can also tolerate these maritime conditions.
Fernandezian Native Grassland
The natural grasslands of both Masafuera and Masatierra are dominated by Stipa laevissima and S. neesiana. Their yellow appearance in summer gives them the look of dry steppe. On Masafuera they occur on the eastern slopes and on the high west barranca. The few other associated species of native origin include Halorrhagis masafuerana (Halorrhagidaceae), Nicotiana cordifolia (Solanaceae) and Wahlenbergia masafuerae (Campanulaceae) all of which are endemic to Masafuera. The remnants of native grassland on Masatierra occur on the northern slopes of the island. Here the associated species include the rare endemic Wahlenbergia fernandeziana (Campanulaceae), while in the more stony areas shrubs such as the endemic Rea pruinata (Asteraceae) make an appearance. Bryophytes, such as Ptychomnium fernandezianum and Rhacopilum fernandezianum, and lichens are also important elements especially in the more rocky areas.
Fernandezian Lower Montane Forest
These forests of Juan Fernandez have a similarity to the laurineous forests of Macronesia and the Metrosideros forests of the Hawaiian BioProvince, but also have many elements linking them to the Valdivian rain forests of Chile. Unlike these mainland forests, however, both Nothofagus (southern beech) and woody climbers are absent. Structurally they can be divided into four layers – an upper canopy (with certain trees reaching heights of 30 m or so), a sub canopy above 6 m, a shrub layer of roughly between 2 - 6 m, a field layer of between 0.2 and 2m, and a ground layer of under 0.2 m (mostly formed of cryptogams). On Masatierra the upper canopy mainly comprises the two endemic species Fagara mayu (Rutaceae) and Nothmyrica fernandeziana (Myricaceae), while the lower canopy includes Drymys confertifolia and the endemic Boehmeria excelsa (Urticaceae), Coprosma pyrifolia (Rubiaceae), Juania australis (Arecaceae), Rhaphithamnus venustus (Verbenaceae) and Sophora fernandeziana (Fabaceae). The endemic sandalwood Santalum fernandezianum (Santalaceae) was also thought to have been abundant in bygone years but now appears to be extinct. The shrub layer is also mainly populated by endemic species such as Rea micrantha, Symphochaeta macrocephala (Asteraceae) and Gunnera peltata (Gunneraceae). The latter is, in fact, the largest herb on the island occasionally reaching heights of 5 m. Also important within the shrub layer is the magnificent endemic fern Thyrsopteris elegans (Thyrsopteridaceae) with fronds well over the height of a man. Among the larger field layer species are various endemic dwarf shrubs such as Halorrhagis masatierrana (Halorrhagidaceae) and Wahlenbergia larrainii (Campanulaceae), the endemic graminoids Bromus fernandezianus (Poaceae), Carex berteroniana and Uncinia douglasii (Cyperaceae), and a rich collection of endemic ferns including Aspenium stellatum (Aspleniaceae), Blechnum cycadifolium (Blechnaceae), Dicksonia berteroana, Dryopteris inaequalifolia (Dryopteridaceae), Polystichum berterianum (Dryopteridaceae) and Pteris berteroana (Pteridaceae). Three of these, Blechnum cycadifolium, Dryopteris inaequalifolia Dicksonia berteroana, are tree ferns, although the first two species rarely reach heights of more than a metre. Dicksonia, on the other hand, has on occasion measured up to 6 m. Ground layer species are mainly bryophytes such as Isopterygium fernandezianum and Lophocolea fernandeziensis. Bryophytes together with lichens also form the bulk of the rich epiphytic flora, while the few vascular epiphytes include the endemic Peperomia fernandeziana (Piperaceae) and the endemic fern Polypodium intermedium (Polypodiaceae). On Masafuera, the lowland forests have a slightly different species composition. Among the upper canopy trees, Nothomyrica fernandeziana is replaced by the endemic Myrceugenia schulzei (Myrtaceae), and Fagara mayu is replaced by the smaller endemic Fagara externa (Rutaceae). In the undergrowth, Gunnera peltata is replaced by the smaller endemic Gunnera masafuerae (Gunneraceae) and Halorrhagis masatierrana is replaced by the endemic Halorrhagis asperrima (Halorrhagidaceae). Other differences include the presence of the endemic herbaceous species Solanum masafueranum (Solanaceae) and the endemic fern Blechnum longicauda in the field layer, and a more frequent presence of the miniature endemic tree Urtica fernandeziana (Urticaceae).
Fernandezian Upper Montane Forest
Above an altitude of about 500 m the forests gradually take on a different character. On Masatierra these upland forests extent to the highest parts of the island including the summit of El Yungue the highest peak at 927 m. Masafuera, on the other hand, reaches a sufficient height, about 1500 m, to give rise to a climatic timber-line. Nevertheless, the remaining montane forests are still better developed on Masatierra. Frequent fogs characterize the zone, and the forests differ from lowland areas by an increasing frequency of ferns, particularly the endemic tree fern Dickinsonia berteroana (Dickinsoniaceae). In fact, these upland forests have been described as fern forest. From a structural point of view, the same layering occurs as in the lowland forests with an upper and lower canopy, shrub, field and ground layer. Characteristic upper canopy trees include several endemic species including Azara fernandeziana (Flacourtiaceae), Dickinsonia berteroana, together with Nothomyricia fernandeziana and several other species commonly encountered in lowland forest. The lower canopy also includes many lowland species, but among the shrub layer are several endemics more or less confined to the montane zone. These include Cuminia fernandeziana (Lamiaceae), Lactoris fernandeziana (Lactoridaceae), Ugni selkirkii (Myrtaceae) and Wahlenbergia grahamae (Campanulaceae). An interesting feature of Juan Fernandeziana is the large number of small rosette trees that have evolved. Altogether there are 25 species 9 of which are endemic and several of these belong to endemic genera. In the uplands these include Centaurodendron dracaenoides (Asteraceae), various species of Dendroseris, Phoenicoseris pinnata (Asteraceae) and Yunquea tenzii (Asteraceae). The latter species is confined to the summit of El Yunque. All these particular taxa belong the family Asteraceae, but this life form has evolved in four different families. The moist conditions of these forests have allowed a rich epiphytic flora to develop. For example, Rhetinodendron berterii is often an epiphyte on other larger species such as Dickinsonia. Epiphytic ferns are particularly well represented and include several endemic filmy-ferns such Serpyllopsis caespetosa var. fernandeziana (Hymenophyllaceae), Trichomanes philippianum (Hymenophyllaceae) and the distinctive bronze-green Hymenophyllum rugosum (Hymenophyllaceae). Ferns and bryophytes also mainly populate the field layer. The few herbaceous vascular plants include the two endemic species Dysopsis hirsuta (Euphorbiaceae) and Peperomia berteroana (Piperaceae) both of which are not uncommon in the wetter, shady areas.
Fernandezian Brushwood
Brushwood or scrub appears to form the climatic climax vegetation on exposed ridges such as on the crest of Cordon Escarpado and at the foot of steep escarpments. Virtually all the dominant shrubs are endemic. On Masatierra these include Berberis corymbosa (Berberidaceae), Colletia spartioides (Rhamnoides), Cuminia fernandezia (Lamiaceae), Dendroseris marginata, Robinsonia gayana (Asteraceae), Eryngium bupleuroides (Apiaceae), Escallonia callcottiae (Saxifragaceae), Pernettya rigida (Ericaceae), and Selkirkia berteroi (Boraginaceae). However, the composition of species dominating the shrub layer varies from place to place. In the more exposed areas Escallonia callcottiae and Pernettya rigida are usually the main species. Another frequent plant of shrub stature is the large endemic herbaceous species Gunnera bracteata (Gunneraceae). The field layer is likewise populated mainly by endemic species such as Erigeron fruticosus (Asteraceae), Halorrhagis masatierrana (Halorrhagidaceae), Margyricarpus digynus (Rosaceae), Plantago fernandezia (Plantaginaceae) and Wahlenbergia fernandeziana (Campanulaceae). At ground level bryophytes, such as Lepidozia fernandeziensis and Ptychomitrium fernandezianum, and lichens, like Blastenia fernandeziana and Porina fernandeziana, usually predominate.
Fernandezian Subalpine Fern-Grass Heath
Confined to the higher island of Masafuera these heathlands make their appearance at an altitude of about 700 m. They are typically dominated by Lophosoria quadripinnata, the endemic tree fern Dickinsonia externa (Dickinsoniaceae), and the endemic Gunnera masafuerae (Gunneraceae). Other less common shrubs include the endemic Robinsonia masafuerae (Asteraceae), while the field layer commonly includes Pernettya rigida and the endemic eyebright Euphrasia formosissima (Scrophulariaceae).
Fernandezian Alpine Fern-Grass Heath
At an altitude of about 1100 m on Masafuera, the heath becomes more alpine in character and most of the shrubs take on a stunted appearance. At these altitudes there is a significant Magellanian element represented in part by Lagenophora hariotii, Rubus geoides, Uncinia brevicaulis and the endemic Acaena masafuerana (Rosaceae), Galium masafueranum (Rubiaceae) and Luzula masufuerana (Juncaceae). The dominant grasses include the two endemic species Agrostis masafuerana and Bromus masafuerana (Poaceae), while the main fern is Gleichenia quadripartita. Other endemic species characteristic of this zone includes Abrotanella crassipes, Erigeron luteoviridus (Asteraceae) and Urtica masafuerae (Urticaceae). Several of these alpine heath species, particularly Abrotanella crassipes, can be found on the summit ridge of Los Inocentes at 1500 m. Bryophytes and lichens are also well represented including Thuidium masafuerae and Caloplaca selkirkia.
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