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Alejandro A. Royo

Alejandro A. Royo
Research Ecologist
Sustaining Forests in a Changing Environment
335 National Forge Road
Irvine, PA 16329-0267
United States
Current Research
My main research focus investigates the role of the factors that regulate the diversity and abundance of vascular plants in forest understories.  These drivers include natural and anthropogenic disturbances, herbivory, competing vegetation, pests and pathogens, and climate change.  I am involved in multiple projects throughout the United States and Canada asking questions on various subsets of these forces on plant diversity.  These projects range from invasive pests decimating Ash populations, to American chestnut reintroduction efforts, to ungulate impacts on plant communities, to the role climate-adaptive management strategies can play in mitigating climate change effects on forests.
Past Research
Past research had a focus on the maintenance of herbaceous species diversity in both temperate and tropical systems and the role of seed-banking as a mechanism to retain and promote diversity in forests.  A substantial part of my early work was on the role of recalcitrant understory layers inhibiting plant diversity, the impact of soil-borne pathogens on early tree establishment, and forest recovery following catastrophic wind disturbance and salvage logging.
Research Interest
I plan on continuing my research programs on the maintenance of tree and herbaceous species diversity in both temperate hardwood and mixed-wood systems in the tension zone between the temperate hardwoods and boreal systems.
Why This Research Is Important
Among the many factors that determine forest understory diversity prior to any overstory disturbance, competition and herbivory are typically thought of as preeminent. Understanding how these two factors, alone and in concert, act to promote or reduce plant diversity is key to the sustainable management of forest resources.
  • University of Pittsburgh, Ph.D., Ecology and Evolutionary Biology, 2005
  • University of North Carolina, Greensboro, M.S., Department of Biological Sciences, 1998
  • University of North Carolina, Greensboro, B.A., Department of Biological Sciences, 1993
  • University of Pittsburgh, Graduate Certificate, Latin American Studies, 2005
Professional Organizations
  • Ecological Society of America,  Current
Featured Publications
Other Publications
Research Highlights

Genetic Information on Ash Informs Treatments for Emerald Ash Borer 

Year: 2018
Forest managers can use insecticide treatments to protect ash trees from emerald ash borer to conserve the genetic diversity of ash. But which trees should be protected? Research at the Allegheny National Forest is underway to develop new strategies to conserve ash tree diversity.

Managing the foodscape to alleviate deer browsing

Year: 2017
Forest plant biodiversity is being degraded by browsing from overabundant deer herds, but forest management can alleviate impacts. Research by Forest Service scientists and their partners has expanded understanding of how forage availability throughout the landscape, or the “foodscape,” influences b...

Sprouts as Rapid Bioassays of Browse Impact

Year: 2016
Effective browse pressure indicators are necessary to adaptively manage forest landscapes with resident deer. Hardwood tree stump sprouts are a reliable and easily measured phytoindicator in disturbed forests. Deer browsing reduced sprout height by 39 percent when averaged across tree species. Brows...

International Symposium Improves Understanding of Disturbance and Salvage Logging and Forest Sustainability

Year: 2015
The Forest Service’s Northern Research Station along with the University of Pittsburgh and the Carnegie Museum of Natural History sponsored an international symposium in May 2015 where international research teams and forest managers addressed the ecological and economic costs and benefits of distur...

Hurricanes Disturb Non-tree Subtropical Wet Forest Species Composition

Year: 2011
Hurricane disturbance caused pronounced and persistent changes in the non-tree species composition of a subtropical wet forest. A unique long-term Forest Service dataset tracked the response and recovery of tropical forest herb, shrub, and vine communities to multiple hurricanes over 21 years on the...

Landscape-level Deer Herd Reductions Restore Forest Understory Plant Communities but Not Species Diversity

Year: 2010
Since 2001, NRS scientist Alejandro Royo has tracked the response of herbaceous plant communities to deer herd reductions throughout the 70,000-acre Kinzua Quality Deer Cooperative (KQDC) in northwestern Pennsylvania.

Can We Bank on Forest Seed Banks

Year: 2012
Community composition of seeds stored in forest soils becomes increasingly divergent over time