TY  - BOOK
AU  - Johnsson,Kristina
TI  - The black woodpecker Dryocopus martius as a keystone species in forest
PY  - 1993///
CY  - Uppsala, Sweden
PB  - Swedish University of Agricultural Sciences, Dept. of Wildlife Ecology
KW  - Black woodpecker
KW  - Sweden
KW  - Cavity-nesting birds
KW  - Ecology
KW  - Forest ecology
N1  - Thesis consists of summary chapter and seven articles or submitted manuscripts; Includes bibliographical references
ER  -