General Impact
Euphorbia esula develops extensive root systems that can reach 4.5m below the soil surface and up to 10m laterally. E. Esula outcompetes native vegetation by consuming available water and nutrients through its extensive root system, sprouting new plants out of the existing root system, and by shading sunlight and excreting toxins that inhibit growth of surrrounding plants. These toxins also repel cattle and horses. An infestation of leafy spurge eliminates forage-worthy grasses while providing no nutritional value. It forms dense stands in early spring, shading out the native plants beneath as they emerge, stunting or killing them. An extensive and resilient underground root structure is fast to replace any shoots that become damaged during the growing season, prior to the plant's flowering. By midsummer, leafy spurge produces high yields of pollen and seed, up to 3,400 pounds of seed per acre, setting the stage for the next spring, and further spread. For humans who make accidental contact with the milky sap contained in leafy spurge the consequences range from minor skin irritation to total blindness if the liquid is rubbed on the eyes. Grazing cattle, horses and sheep tend to avoid the plant, but if they must eat it, the result can be digestive problems, weakness, even death (D'Ancona, J., 2004).
Location Specific Impacts:United States (USA) 
Agricultural: Reduces value of the range because cattle and horses avoid it.
Competition: Outcompetes native plants by dominating the nutrient supply and blocks sunlight from smaller plants.
Economic/Livelihoods: Costs ranchers between 35 and 45 million dollars a year in control and loss of range land.
Modification of nutrient regime: Outcompetes natives for nutrients because it has such an extensive root structure. North Dakota (United States (USA))
Modification of nutrient regime: In a study on the effects of invasive plants on grassland birds;on the Sheyenne National Grassland (SNG), North Dakota, USA, 1999-2000, it was found that grasshopper sparrow (Ammodramus savannarum) and savannah sparrow (Passerculus sandwichensis) densities were lower on high-spurge points than on low- and medium-spurge points. Conclusions drawn from the study were that vegetation structure is an important indicator of habitat quality and resource availability for grassland birds. Changes in vegetation structure caused by introduced plant species, such as spurge, can alter resource availability and hence affect bird community composition. Managers of spurge-infested grasslands should continue current spurge control measures to help prevent further declines in grassland habitat quality and grassland bird populations (Scheiman et al., 2003).
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