1921] CURRENT LITERATURE 243 
equal to that now standing. The character and extent of the destruction are 
indicated by MunceER, and have been given in more detail by HormaNNn” in 
a most interesting article. A great burn occurring in 1902 in south-central 
Washington, and devastating more than half a million acres, was made the site 
of an important investigation of some of the problems of natural reforestation. 
The resulting report?! shows the importance of a careful ecological study of all 
the factors concerned. In spite of the complete and apparently hopeless desola- 
tion succeeding this fire, typical of hundreds of similar conflagrations in the 
Douglas fir region, HorMANN found that a good even-aged stand of reproduc- 
tion immediately followed. This extended over the greater portion of the dev- 
astated area, regardless of the presence or absence of surviving seed trees, and 
was shown to be due to an abundance of seed stored in the duff of the forest 
floor and retaining its viability through the fire. The efficiency of seed trees in 
restocking the ground was found to be limited to a radius not exceeding 300 
feet from the parent tree, hence they were not important in the reforestation of 
so large an area. Local failure in reforestation within this area was found to 
be due either to the complete destruction of all the duff, with its contained 
seed, over certain portions of the area and more particularly upon the drier 
southern slopes, or to the occurrence of a second fire after all the viable stored 
seed had germinated. This resulted in the destruction of all the seedlings 
before they were old enough to bear seed to restock the forest floor. The 
burial of seeds and cones by rodents was found to be an important factor in 
stocking the duff. 
More recent investigations by HorMANN” of the ecology of these forests 
show the Pseudotsuga to be unable to withstand shade, and hence to constitute 
the principal member of a pioneer forest of which Thuja and Tsuga form the 
climax. The characteristics of the Douglas fir which give it such a prominent 
place in the Washington and British Columbia region are given as follows: 
“The production of heavy crops of seed which is the favorite food of the 
indigenous rodents; caching of seed by rodents in the forest floor; ability 
of the seed to retain its viability while stored in the forest floor and to live 
through forest fires; early and quick germination of the seed under favorable 
conditions; and a rapid development of a long radicle.” 
Many of these factors are somewhat within the control of man, and 
upon them the scientific management of Douglas fir forests must be based. 
Such a system has been described by MUNGER (loc. cit.) and in its bare out- 
line consists in: (r) logging clean, (2) falling dead trees or ‘“‘snags,” which 
2° HorMaNN, J. V., How fires destroy our forests. Amer. Forestry 26:329-336. 
Sigs. 7- 1920. 
eieesmecnge prgage aces from seed stored in the forest floor. Jour. Agric. 
Res. 11: I-26. pls. 7 
, The iain ce of a Douglas fir forest. Ecology 1:49-53. fig. I. 
22 
1920. 
