8. Phytogeographic Relationships and Regional Richness Patterns
141
isotherm equ al or inferior to 16°C, cloud y summers, and absence of
natural fire as useful crite ria'. We have relaxed the 10% summer rainfall
requirement to allow for 9% rainfall, given the existence of areas with
over 150mm on the Pacific coast of Chile that still receive as much as
150mm rainfall over the summer months, yet under 10% of the annual
tota l.
The rainforest zone delimited here is depicted in Figure 8.4. The
nort hern limit is set at around 38°30' S in the Andes to include areas
•
Boreal Temperate Rain Forest
m:II Perhumid Temperate Rain Forest
~ Seasonal Temperate Rain Forest
(j) Valdivian Rain Forest
® North Patagon ian Rain Forest
@ Magellan ic Rain Forest
Scale
I : 15000000
290
9
290 4Cf 690 Km
34°
38°
42°
46°
50°
54°
...,
,
I
I
/
"
16°
3
a,
\
\
\
\
ARGENTINA
\
\
\
\
\
\
\
\
, ..... ............ .... _16°
_. ...
Figure 8.4. Distribution of cool temperate rainforest in southern South America,
based on criteria outlined in text . The major rainforest zones according to Veblen
et al. (1983) (vertical lines), and divisions according to Weigand (1992) (shaded
areas) are shown.