Survival and Growth of Three Invasive Plant Species in Five Different Forest Management Regimes across a Moisture Gradient

Research Issue

Forest site conditions (natural and anthropogenic, including forest management regimes) that restore native species composition to more desirable and sustainable conditions as well as decrease the likelihood of invasion by exotic plants need to be better defined.  

 Our Research

Use of fire and harvesting to manage Eastern oak forests may facilitate invasion of these ecosystems by nonnative invasive plant species (NNIS).  Like oaks, NNIS may respond positively to an increase in light caused by disturbance.  This is especially true for intensive harvesting. Plant response to such treatments and fire behavior are also likely to vary across large- and small-scale moisture gradients.  Our first objective is to evaluate NNIS response to diameter-limit cutting compared to fire and shelterwood harvesting at both landscape and micro-topographic scales.  Our study area includes the Ridge and Valley and Allegheny Plateaus Provinces in West Virginia and Ohio and north and south-facing slopes as landscape and topographic blocking factors, respectively.  Five forest management types will be evaluated, including single burns, repeat burns, shelterwood harvests, diameter-limit harvests, and no management.  Growth of three regionally problematic NNIS (Ailanthus altissima, Microstegium vimineum, and Alliaria petiolata) and the native species Quercus rubra will be evaluated in uninvaded sites. Secondly, we will compare dispersal rates and seed dormancy patterns of sites that have already been invaded.  We will also evaluate light thresholds for the three NNIS compared to Quercus rubra.  Finally, we will incorporate the site vulnerability, propagule pressure, and critical light level information into forest growth and yield models for each management type. Our findings will enable land managers to prioritize areas to burn or harvest or delay management.  

Expected Outcomes

Our earlier research (cited below) reveals that exotic plants tend to prefer resource-rich sites (i.e., ample water, light, and nutrients) during the early-establishment stage.  We, thus, anticipate that the more mesic sites of this new study will show the greatest survival and growth of the three focus NNIS.   Because many native species also are more likely to be found on resource-rich sites, we expect to see a correlation of survival and growth with native species richness.  We also anticipate that the disturbances resulting in the most canopy opening (shelterwood and diameter limit harvests) will result in the greatest invasions and greatest positive native species response.  We hope to define a fine enough gradient that shows a point where positive native species response is increasing but positive invasive species survival and/or growth is beginning to decline. This response is likely to vary among the three species.  

Research Results

Huebner, C.D. 2003.  Vulnerability of oak-dominated forests in West Virginia to invasive exotic plants:  Temporal and spatial patterns of nine exotic species using herbarium records and land classification data. Castanea 68(1): 1-14.

Huebner, C.D. and P.C. Tobin.  2006.  Invasibility of mature and 15-year old deciduous forests by exotic plants.  Plant Ecology 186:57-68.

Huebner, C.D., R.S. Morin, A. Zurbriggen, R.L. White, A. Moore, and D. Twardus. 2009. Patterns of exotic plant invasions in Pennsylvania’s Allegheny National Forest using intensive Forest Inventory and Analysis plots. Forest Ecology and Management 257: 258-270.

Research Participants 

Principal Investigator

• Cynthia D. Huebner, Research Botanist/Ecologist, U.S. Forest Service, Northern Research Station

Research Partners

• Gary W. Miller, Research Forester, U.S. Forest Service
• Glen Matlack, Ohio University, Plant Ecologist
• David McGill, West Virginia University, Extension Forester
• Rakesh Minocha, Research Plant Physiologist, U.S. Forest Service, Northern Research Station
• Mathew Dickinson, Research Fire Ecologist, U.S. Forest Service, Northern Research Station
• Chris LeDoux, Research Industrial Engineer, U.S. Forest Service, Northern Research Station
• Monongahela National Forest
• Wayne National Forest
• George-Washington Jefferson National Forest
• Zaleski State Forest, Ohio
• Richland-Furnace State Forest, Ohio
• Strouds Run State Park, Ohio
• Green Ridge State Forest, Maryland
• Plum Creek Lumber
• Beckwith Lumber
• NewPage Corporation 
• Pardee-Curtin Lumber
• Douglas Grimes (WV landowner)
• Scott Funkhouser (WV landowner)
• Viola Riggleman (WV landowner)
• Jesse Clary (OH landowner)

For further details log on website :
https://www.nrs.fs.fed.us/disturbance/invasive_species/nnis_growth/