AMOUNT OF LITTER PRODUCED. 771 



under favourable circumstances may carpet the ground over 

 extensive areas. If these carpets are formed of the larger 

 kinds of moss, they yield a very important form of litter. 



Of the mosses employed usually for litter, several species of 

 the large genus Hypman and of other genera are common, 

 as:* Ilypiitim Schreberi, pnriini, ciispidatum, molluscum, 

 cupressiforme ; Hylocomium splendent, squarroxuin, ti'iquetrum 

 and loreum ; Brachythecium nitabulum ; Campothecwftn lutes- 

 ccns ; Tlniidium tamariscinuni and abietinum, etc.; also Poly- 

 triclnim formosuni and urnigerum ; Dicranum scoparium , 

 Bartramia fontana ; Climatium dcndroides ; on wet, swampy 

 ground, besides some of the above, species of Sphagnum 

 predominate. 



The quantity of moss in a forest that may be used for 

 litter, depends chiefly on the species of tree of which the 

 standing-crop is composed, the age of the wood, and the 

 system of management. 



As regards species of tree, moss is most prevalent in coni- 

 ferous woods, and especially in those of spruce and silver-fir ; 

 it is rare for broadleaved woods to produce moss in sufficient 

 abundance to be utilizable as litter. The older the trees, the 

 greater the amount of moss, unless opening the cover should 

 admit sunlight and dry the soil, when the mosses cease to 

 thrive. The system of management followed is also 

 influential. 



It is chiefly the annual fall of dead leaves in broadleaved 

 woods that forms an obstacle to the growth of moss, as they 

 intercept the small amount of light which mosses require, and 

 small tufts of moss which may be produced here and there are 

 stifled by the dead leaves falling on them in succeeding years. 

 It is different in coniferous woods : the thinner coating of dead 

 needles affords room for the spread of any mosses which have 

 germinated and sufficient light for their development. As the 

 moss then grows regularly through the annual fall of needles, 

 the litter consists of an inseparable mixture of moss and 

 dead needles, and only exceptionally can they be collected 

 separately. 



* Vide Braithwaite's "British Moss Flora"; also James' " Field- Flora of 

 Mosses." 



3 D 2 



