Canadian Forestry Journal, February, 1919 



63 



more convincing, there arose naturally the ques- 

 tion, 'What was the source of seed for all this 

 reproduction?' The answer to this question also 

 developed naturally enough the accumulation of 

 evidence throughout the burn. It was found 

 that the reproduction most often occurred, not 

 in a solid unbroken cover, but in various-sized 

 patches with very irregular and ramifying boun- 

 daries. Where the reproduction was lacking, the 

 ground was covered with grasses, herbaceous 

 plants, and shrubs, evidencing an uninterrupted 

 growth since the burn was formed. The occur- 

 rence of these two types of cover made an in- 

 terlaced pattern resembling mosaic over the 

 entire burn, although each type often expanded 

 solidly over a slope or basin many acres in 

 extent. Everywhere the feature that was most 

 striking was the sharp line of demarcation be- 

 tween the reproduction and the grass areas. For 

 all its tortuous windings the boundary was al- 

 ways distinct. Obviously such a condition could 

 not have resulted from any process of overhead 

 seeding, but must rather have been produced 

 by some action on the surface of the ground 

 itself. The idea of ground lire suggested itself. 

 One who has seen ground fire burning in forest 

 duff will remember that it burns very irregularly, 

 here leaving an island and there forming a deep 

 bay between two points of unburned ground. 

 When at length the smoldering fire is stopped, 

 the result is just such a mosaic of burned and 

 unburned territory as has been described for the 

 reproduction and grass territory. 



"The likelihood that any part of the forest 

 floor will burn depends on a number of varying 

 factors, such as the quantity and kind of 

 humus soil and its moisture content. Most 

 severe ground fires occur on dry sites, provided 

 those sites have a sufficient quantity of duff to 

 carry fire at all. Accordingly the reproduction 

 occurs most densely in the moist sites and is open 

 or lacking on exposed dry sites, although this 

 may be partly due to the fact that these dry 

 sites are very unfavorable to the establishment 

 of seedlings even though germination may take 

 place. Furthermore, irregularity in the areas of 

 young growth occurred on all sorts of sites. This 

 could lead to but one conclusion: wherever 

 ground fire occurred no reproduction appeared, 

 except close to seed trees where seed could be 

 cast upon the burned ground after the fire. 



"From this it was but a step to the complete 

 explanation: wherever the duff and litter were 

 burned out of the forest floor, there developed an 

 area barren of reproduction; wherever the duff 



and litter were not burned out of the forest floor, 

 there developed an area of m.ore or less dense 

 reproduction. Therefore, the duff must be the 

 controlling element: the duff must be the storage 

 medium of the seed, and that seed must have 

 been produced and stored in the forest floor be- 

 fore the fire and have retained its vitality 

 through the fire. 



"Before this conclusion is accepted, however, 

 another possible source of seed must be con- 

 sidered. Is it not possible that cones carried 

 through the fire on the crowns of trees severely 

 burned or killed furnished the seed from which 

 the young growth originated? After the fire 

 these cones may possibly have opened and dis- 

 persed their seed, becoming in that way an over- 

 head source for the restocking of the burn. In 

 fact, a very small percentage of germination of 

 white-pine, noble-fir, and cedar seed has been 

 secured from seed which passed through a crown 

 fire. But even though this source does contri- 

 bute some seed, it does not explain the great 

 mass of reproduction, which, by its mosaic oc- 

 currence, demonstrates conclusively the impos- 

 sibility of its having come from overhead seed 

 distribution subsequent to the fire. The principal 

 factor in reproduction after fire must be the seed 

 stored in the duff. 



LAMINATED GUN STOCKS. 



The U.S. Forest Products Laboratory at 

 Madison. Wis., has developed a method of 

 making laminated gunstocks which would, with- 

 out reducing the strength, permit the use of the 

 small pieces of walnut not suitable for single 

 piece stocks. This would facilitate production 

 and result in appreciable saving in costs and 

 material. 



The application of laminated construction to 

 many articles of trade is a development worthy 

 of close study. Shoe lasts, bowling pins, saddle 

 trees, oars and paddles, tanks, barrels and kegs, 

 and various parts of vehicles and agricultural 

 instruments may possibly be constructed with 

 laminated wood. 



The laboratory is working on the drying of 

 willow for artificial limbs. There is a shortag.^ 

 of material and the demand for artificial limbs 

 will increase. It takes from three to five years 

 to air-season the slock, but indications are that 

 it can be done in kilns in from sixty to seventy 

 davs. 



