Woody plant dominance in grasslands can dramatically alter ecosystem structure and function. I have examined the effects of woody plant encroachment on soil nutrient pools and microbial communities in south Texas (McCulley et al. 2004, 2007), in central Texas (McCulley and Jackson, In Press), and in sites throughout the southwestern U.S. (McCulley et al., 2004). We are currently involved in work addressing this topic in the Iberian Peninsula, where a native woody shrub, Cistus ladanifer, is invading annual grassland dominated cork oak savannas (shown below).
Cistus ladanifer invading cork oak savanna in Portugal.
Cork oak savannah without Cistus invasion,