A dam that size would have its reservoir encroach into Canada, which would violate treaties. To many tribes, however, the proposed regulations will further encroach on tribal sovereignty. The US failed to prevent settlers from continuing to encroach on Choctaw territory. This call becomes louder if trespassers encroach upon the Australian raven's territory. Meanwhile, the English settlers continued to encroach on Powhatan territory. The Karluks took this opportunity to encroach on Uyghur territory and annexed the Futu valley. Sand dunes can have a negative impact on humans when they encroach on human habitats. European-American settlers continued to encroach on western lands. As humans encroach into their habitat the incidents of conflict increase. As humans encroach into their habitat, attacks are few but not unknown. The French monarchy asserted its rights to encroach on Edward's legal rights in Gascony. Without disturbance, trees will encroach on a grassland and cast shade, which suppresses the understory. He uses muscle power to encroach land and make money. They were granted a small reservation, which settlers continued to encroach on. However, they generally only encroach upon farms when natural food is scarce.