Non-Native Invasive Plants

Non-native invasive plants that gain a foothold in the Red Maple Seepage Swamp must be able to tolerate saturated soils. The harms caused by non-native invasive plants include competition with natives for soil nutrients, sunlight, and pollinators, and degradation of animal habitat. (* indicates non-native)

• crabapple* (tree)
• English ivy* (vine) 
• garlic mustard* (low plant)
• Japanese barberry* (shrub)
• Japanese honeysuckle* (vine) 
• Japanese snowball* (shrub)
• mile-a-minute weed* (vine)
• porcelain-berry* (vine)
• privets* (shrub)
• winter creeper* (vine)

Diseases, Pests, and Other Threats

Current and potential ecological threats for the Red Maple Seepage Swamp in Rock Creek Park include the following:

• Disturbance of groundwater processes (including paving over too much land surface): reduction in groundwater availability     Ecobit: Rain, Rain, Go Away—But Where?
• Prolonged or repeated drought: reduction in groundwater availability
• Flash flooding: damage from high velocity and frequency of floodwaters; polluted urban and agricultural stormwater runoff
• Asian long-horned beetle (potential): damage to red maple
• Emerald ash borer (potential): damage to green ash
• Viburnum leaf beetle (potential): damage to blackhaw and southern arrow-wood