8. Phytogeographic Relationships and Regional Richness Patterns
151
the Andes (Dimitri , 1972). There are probably some 850 to 900 vascular
plant species in all temperate forest types in southern South America,
(excluding low-elevation sclerophyllous forest and matorral) (Arroyo
et al., unpublished data). The climatically defined cool temperate rainforest as a whole (including seasonal and nonseasonal rainforest) , as
revealed by the present ,survey, contains a total of 443 vascular plant
species in 205 genera and 96 families (see Tables 8.2, 8.3 and the
appendix). These data, which were assembled from herbarium records
and numerous published phytosociological studies, floristic lists, and
regional floristic works with good habitat data, with elimination of some
species of doubtful identification, are probably fairly representative of the
rainforest flora, although some additions are likely. Unless there was at
least one explicit reference to existence of a species in forest, it was not
considered . Such woody species as Aerisione dentieulata, Azara serrata,
A . alpina, and Citronella mueronata are found within the latitudinal
range of rainforest, but cannot be corroborated for the rainforest habitat
explicitly. Berberidopsis eorallina might also occur in rainforest, as might
the more typical Magellanic moorland endemic Lepidothamnus fonekii ,
occasionally. Thus, nothwithstanding some minor additions, approximately
one third of all vascular plant diversity south of 40°S, and close to one
half of all temperate forest species can be found in the rainforest habitat.
Many such species, of course , also occur in adjacent habitats .
Considering seasonal and nonseasonal rainforest combined , the woody
flora comprises 160 (36%) woody species derived from 82 genera and 50
families, and 283 (64%) herbaceous species in 128 genera and 55 families
(Table 8.2). There are 44 species of trees from 32 genera and 20 families.
Reflecting the high degree of generic endemism in southern South
American rainforest , 26 (81%) of the tree genera present in rainforest are
represented by a single species. However, a comparison of the appendix
with Table 8.1 shows there are many nonendemic genera with single
species. A low number of species per genus tends to be common to all
taxonomic groups but ferns in the rainforest habitat (Table 8.4).
The largest tree genus in rainforest is Nothofagus (7 spp), followed by
Lomatia (Proteaceae) (3 spp.), and Podoearpus ,Amomyrtus, Myreeugenia
and May tenus (2 spp. each) . Although the largest family for trees is the
Fagaceae, the Myrtaceae far exceed Fagaceae in species richness when
sedentary and climbing shrubs (9 spp.) are added to trees (6 spp.). Only a
minority of the tree genera (seven, or 16%) are gymnosperms (Arauearia,
A ustroeedrus , Fitzroya, Pilgerodendron, Podoearpus, Prumnopitys, and
Saxegothaea). In North America, gymnosperms are dominant throughout
and seem to thrive in cool coastal conditions (Franklin , 1988). Some
South American gymnosperms tend to occur in upland habitats and/or
areas with poor soils (Fitzroya, Arauearia, and Pilgerodendron) , while
others (e.g., Podoearpus spp., Saxegothaea) form stable communities
151
the Andes (Dimitri , 1972). There are probably some 850 to 900 vascular
plant species in all temperate forest types in southern South America,
(excluding low-elevation sclerophyllous forest and matorral) (Arroyo
et al., unpublished data). The climatically defined cool temperate rainforest as a whole (including seasonal and nonseasonal rainforest) , as
revealed by the present ,survey, contains a total of 443 vascular plant
species in 205 genera and 96 families (see Tables 8.2, 8.3 and the
appendix). These data, which were assembled from herbarium records
and numerous published phytosociological studies, floristic lists, and
regional floristic works with good habitat data, with elimination of some
species of doubtful identification, are probably fairly representative of the
rainforest flora, although some additions are likely. Unless there was at
least one explicit reference to existence of a species in forest, it was not
considered . Such woody species as Aerisione dentieulata, Azara serrata,
A . alpina, and Citronella mueronata are found within the latitudinal
range of rainforest, but cannot be corroborated for the rainforest habitat
explicitly. Berberidopsis eorallina might also occur in rainforest, as might
the more typical Magellanic moorland endemic Lepidothamnus fonekii ,
occasionally. Thus, nothwithstanding some minor additions, approximately
one third of all vascular plant diversity south of 40°S, and close to one
half of all temperate forest species can be found in the rainforest habitat.
Many such species, of course , also occur in adjacent habitats .
Considering seasonal and nonseasonal rainforest combined , the woody
flora comprises 160 (36%) woody species derived from 82 genera and 50
families, and 283 (64%) herbaceous species in 128 genera and 55 families
(Table 8.2). There are 44 species of trees from 32 genera and 20 families.
Reflecting the high degree of generic endemism in southern South
American rainforest , 26 (81%) of the tree genera present in rainforest are
represented by a single species. However, a comparison of the appendix
with Table 8.1 shows there are many nonendemic genera with single
species. A low number of species per genus tends to be common to all
taxonomic groups but ferns in the rainforest habitat (Table 8.4).
The largest tree genus in rainforest is Nothofagus (7 spp), followed by
Lomatia (Proteaceae) (3 spp.), and Podoearpus ,Amomyrtus, Myreeugenia
and May tenus (2 spp. each) . Although the largest family for trees is the
Fagaceae, the Myrtaceae far exceed Fagaceae in species richness when
sedentary and climbing shrubs (9 spp.) are added to trees (6 spp.). Only a
minority of the tree genera (seven, or 16%) are gymnosperms (Arauearia,
A ustroeedrus , Fitzroya, Pilgerodendron, Podoearpus, Prumnopitys, and
Saxegothaea). In North America, gymnosperms are dominant throughout
and seem to thrive in cool coastal conditions (Franklin , 1988). Some
South American gymnosperms tend to occur in upland habitats and/or
areas with poor soils (Fitzroya, Arauearia, and Pilgerodendron) , while
others (e.g., Podoearpus spp., Saxegothaea) form stable communities