Woody Plant Dominance in Grasslands Alters Ecosystem Dynamics

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 2012), 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). Rebecca and Jim spent half of 2014 on sabbatical in Portugal to continue this work and to assess effects of pasture biodiversity renovations on C, N, P stoichiometry in cork oak savannas.

 

  Cistus ladanifer   invading cork oak savanna in Portugal.

Cistus ladanifer invading cork oak savanna in Portugal.

  Cork oak savannah without   Cistus   invasion,

Cork oak savannah without Cistus invasion,

 Cork oak improved pasture.

Cork oak improved pasture.