Johnsson, Kristina, <br/><br/>
The black woodpecker Dryocopus martius as a keystone species in forest / 
Kristina Johnsson. 
 - 144 pages :  illustrations, maps ;  24m. 
<br/><br/> Thesis consists of summary chapter and seven articles or submitted manuscripts 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label> Hadiah 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Black woodpecker--Sweden.<br/>Cavity-nesting birds--Ecology--Sweden.<br/>Forest ecology--Sweden.