49
O.W. Van Auken and J.K. Bush, Invasion of Woody Legumes, SpringerBriefs in Ecology 4,
DOI 10.1007/978-1-4614-7199-8_8, © Springer Science+Business Media New York 2013
Periodic fi res in grasslands, savannas, and encroached woodlands are very important and should not be overlooked or underestimated as management tools. Without
fi re, which was a natural part of the grassland ecosystems (Fig. 8.1 ), the woody
plants are favored rather than the grasses (Van Auken 2009 ). An excellent visual
example of the result of using fi re to control the encroachment of woody species in
tall grass prairie is from the Konza prairie in Kansas (Fig. 8.2 ). In the center of the
photograph is a fi rebreak. To the left of the fi rebreak, the prairie was burned infrequently (once every 10 years). The encroachment of a variety of woody plants is
easily seen. To the right of the fi rebreak, the prairie was burned frequently (once
every 2 years). The lack of woody plants is obvious (this fi gure is modifi ed from
Van Auken ( 2009 ) and was taken by D. C. McKinley). However, burning discontinuous arid and semiarid shrublands or former grasslands today is diffi cult because
of the patchy nature of the communities and the limited amount of light, fl uffy fuel
(Schlesinger et al. 1996 ; Jurena and Van Auken 1998 ).
Should managing or attempting to manage the encroachment of woody legumes
and other woody plants into former grasslands be about the grasslands or about the
new communities that are created, the savannas, or woody legume communities? In
the past, the main concern seems to have been about the grasslands or former grasslands that have been encroached. There have been signifi cant reductions in biodiversity as woody plants have increased their density and basal area in these former
grasslands (Ratajczak et al. 2012 ). A bigger concern seems to be the loss of herbaceous or grass productivity. The density, cover, and biomass of certain woody species, especially the woody legumes, have increased as the density, cover, and
biomass of many species of C 3 and C 4 grasses and other herbaceous species have
decreased in the vast area of grassland where encroachment has been occurring
(Knapp et al. 2008a , b ). The woody legumes are not the only encroaching species.
Various species in more than 30 genera of woody plants have been reported to be
encroaching into worldwide grasslands ( Archer et al. 1995 ). However, the woody
legumes seem to be principle encroachers.
Chapter 8
Management and Community Restoration
O.W. Van Auken and J.K. Bush, Invasion of Woody Legumes, SpringerBriefs in Ecology 4,
DOI 10.1007/978-1-4614-7199-8_8, © Springer Science+Business Media New York 2013
Periodic fi res in grasslands, savannas, and encroached woodlands are very important and should not be overlooked or underestimated as management tools. Without
fi re, which was a natural part of the grassland ecosystems (Fig. 8.1 ), the woody
plants are favored rather than the grasses (Van Auken 2009 ). An excellent visual
example of the result of using fi re to control the encroachment of woody species in
tall grass prairie is from the Konza prairie in Kansas (Fig. 8.2 ). In the center of the
photograph is a fi rebreak. To the left of the fi rebreak, the prairie was burned infrequently (once every 10 years). The encroachment of a variety of woody plants is
easily seen. To the right of the fi rebreak, the prairie was burned frequently (once
every 2 years). The lack of woody plants is obvious (this fi gure is modifi ed from
Van Auken ( 2009 ) and was taken by D. C. McKinley). However, burning discontinuous arid and semiarid shrublands or former grasslands today is diffi cult because
of the patchy nature of the communities and the limited amount of light, fl uffy fuel
(Schlesinger et al. 1996 ; Jurena and Van Auken 1998 ).
Should managing or attempting to manage the encroachment of woody legumes
and other woody plants into former grasslands be about the grasslands or about the
new communities that are created, the savannas, or woody legume communities? In
the past, the main concern seems to have been about the grasslands or former grasslands that have been encroached. There have been signifi cant reductions in biodiversity as woody plants have increased their density and basal area in these former
grasslands (Ratajczak et al. 2012 ). A bigger concern seems to be the loss of herbaceous or grass productivity. The density, cover, and biomass of certain woody species, especially the woody legumes, have increased as the density, cover, and
biomass of many species of C 3 and C 4 grasses and other herbaceous species have
decreased in the vast area of grassland where encroachment has been occurring
(Knapp et al. 2008a , b ). The woody legumes are not the only encroaching species.
Various species in more than 30 genera of woody plants have been reported to be
encroaching into worldwide grasslands ( Archer et al. 1995 ). However, the woody
legumes seem to be principle encroachers.
Chapter 8
Management and Community Restoration