Resource Niche and Trade-offs 165
Gap size (m^2 )
0 500 1000 1500 2000 2500 3000 3500
Survival (%)
0
20
40
60
80
100
Light (% full sun)
0 20 40 60 80 100
Relative growth rate (mg g
−^1
day
−^1
)
0
10
20
30
(a)
(b)
Figure 10.2 Phenotypic reaction norms for seedlin gsurvival and growth rates in relation to li ght availability. (a)
Seedlin gsurvival of seven Guyanan tree species alon ga gradient of gap size (from Rose 2000). The open symbols
represent gap-dependent species, while closed symbols represent shade-tolerant species. (b) Seedling relative growth
rates of 15 Bolivian tree species in relation to experimental shadin gexpressed as % full sun (data from Poorter 1999).
The trend for each species is shown by best fittin gpolynomial re gression.