FOREST WEEDS. 397 



Spaces between plants may be covered with moss, dead 

 leaves or sawdust. This prevents the soil from caking and 

 retains moisture near the surface, and thus replaces completely 

 the expensive processes of working the soil, weeding and 

 watering. In damp places, burned compost introduces liver- 

 wort (Marcliantia polymorpha, L.), but this does no harm to 

 the plants. 



b. Remedial Measures. 



The nature of remedial measures to be adopted depends on 

 the habit of the weeds, their degree of development, and the 

 nature of the locality. The simplest measures will often 

 suffice, but sometimes special measures must be taken as 

 follows : 



i. In order to remove too great a soil-covering of grass and 

 herbage, cattle may be admitted, or the weeds may be pulled 

 up or cut down, always before the blossoming period. In 

 very bad cases the hoe or plough may be used all over the 

 area, and the land made to produce a field-crop before being 

 restocked with forest growth. The cutting of grass and 

 .herbage may be profitable, or the cost of the operation at least 

 covered by the sale of the produce. The weeds when mixed 

 with lime may be collected into heaps, and then yield valuable 

 manure for forest nurseries, or they may be burned and their 

 ashes spread over the soil. 



ii. If the soil is covered with short woody plants they may 

 be mowed down or pulled up, as in the case of heather ; rasp- 

 berries may be simply beaten down, and softwoods, such as 

 sallows, pulled up, or cut off at about one foot from the ground, 

 or the woody plants may be girdled close to the ground. 



This cutting should be done in July, at the height of the 

 growing season, when the power of reproduction is least, 

 as there is then least reserve-material in the roots and 

 rhizomes. In coppice and coppice-with-standards, inferior 

 species such as blackthorn should be cut out several years 

 before the underwood is felled. Binding tightly suckers or 

 shoots of woody weeds with wire is sufficient to kill them. 



iii. To remove from trees the coating of lichens and moss 

 which close their lenticels and deprive them of air, various 



