20 BULLETIN 1200, U. S. DEPARTMENT OF AGRICULTURE. 
The proportion of age classes shows that about one-half of the 
total Douglas-fir reproduction started the first year after the fire, 
about one-third from 2 to 6 years, and the remainder from 7 to 11 
years after the fire. The decrease in germination of seed throughout 
the section after the first few years subsequent to the burn and the 
small percentage of the young age classes found at more than 10 
chains from seed trees indicated that the remaining seed trees had 
not been an important factor in the restocking of the area, espe- 
cially at distances over 10 chains from seed trees. 
These facts are supported by the records of the township study 
given in Table 10. i 
TABLE 10.—ClaSsification of young growth according to age classes and distribu- 
tion on township studied in Yacolt burn. 
Percentage of total 
number of seedlings - Percentage of all seed- 
in each age class lings found, according 
Percent- found within each to age classes. 
age of distance. 
Re thee Distance | ae 
PBEGES- acacia examined Time of germination. | Time of germination. 
: included ; ; 
in each | | Sees] 
distance.| First | 2t06 |7to11} First | 2to6 | 7toll 
| year | years | years ; year | years | years 
| after | aiter | atter after | after | after 
fire. fire fire. | fire. | fire. | fire. 
j | | : | 
Chains.2 | 4 lige 
, Over 10... 89.9 80.6 7.0 12.4 | 
ID QuUClAS, frees LA ere Pie ee GO S24) 4.6 68.5 14.4 LMT ee 6805 TSG 20.4 
0 to 5. 5S oko | pis ae) LSEaT || | | 
Over 10 OBO 2heS.| Age PEs ae | 
Western white pine............ i told.” 120, | Oto a SOO) eo eee } BTS PWS Tee 
OTOH ESS} 1.0 20.0 SOSH Aes eee Fa 3 | 
Over 10...! 89-7 1 OE 3.0 2.9 
Nobicitir ce. oo. ee ee i to 10 5.5 | 190.9 aD 6.9 84.1 ASTD ATED 
| WOE ESR See! 48ulias Ole 2 8.8 24.0 | 
Over 10 Se tain = ORY Det 1.4 | 
SULMershit woes eee ees see | ‘ to 10:22:22 | 55 75.0 DES 4n Sah 2 3 8258) 516: 74 15 
NLO topossse= | 9.3; 80.0 20 Re Gelee | 
| fOver 19 78.4} 26.51 53.0} 20.5 | 
Western heme .--eeeeseee 8 to 10 | 953 25.0 45.8 29. 2 23:16, jen so0nk | 26.3 
0 Co Sseaeeqs) 12-3 49.3 51.6 29.1 | | 
_ 1 The total area included in transects was 32.25 acres. 
2 One chain equals 66 feet; 10 chains equal one-eighth mile. 
The Douglas-fir germination over the entire area in the first year 
after the fire was more than half of the total germination. The fact 
that the germination after the second year following the fire was con- 
fined largely to within 10 chains of seed trees indicated that the 
remaining seed trees were not casting seed over the burn as a whole, 
as germination conditions were still favorable when the examination 
was made 11 years after the fire. , 
The section and township records demonstrate that reproduction 
which germinated 7 to 11 years after the fire is hmited to the vicinity 
of seed trees or to localities which seed can reach because of favor- 
able ‘topography. Trees on a hillside above a canyon disseminate 
their seed over a wider range of territory than trees on level ground, 
for the seed can be blown down into the canyon and across to the 
opposite slope. 
There were no Dougilas fir seed trees on the section studied (see 
fig. 3), except a single broken-topped one, but there were Douglas 
