41. By effecting more neighboring plants, the favorable changes in soil condition contribute to the success of diffuse knapweed . 42. One factor leading to the superior resource competition of diffuse knapweed is its ability to exist in drought conditions. 43. This advantage allows diffuse knapweed to devote its resources to competition while its neighbors are conserving resources to survive. 44. It is now established in knapweed populations throughout the western United States, especially in warm, dry areas. 45. Soldier Beetle " Trichodes alvearius " taking off from a Knapweed flower, showing its bright warning coloration 46. The neutral grassland areas support crested dog's-tail, common knapweed , red fescue, ribwort. 47. Selective pressure, given sufficient time, can cause the adaptation or evolution of invasive species such as diffuse knapweed . 48. Besides the advantages that diffuse knapweed gains from the ERH and allelopathy, it also possesses several characteristically invasive traits. 49. Because cattle prefer the native bunchgrass over knapweed , overgrazing occurs, increasing the density and range of knapweed infestations. 50. Because cattle prefer the native bunchgrass over knapweed, overgrazing occurs, increasing the density and range of knapweed infestations.
