Sarnia vs Savannah

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Sarnia is a city in Southwestern Ontario, Canada, with a 2016 population of 71,594. It is the largest city on Lake Huron and in Lambton County. Sarnia is located on the eastern bank of the junction between the Upper and Lower Great Lakes where Lake Huron flows into the St. Clair River, which forms the Canada–United States border, directly across from Port Huron, Michigan. The site's natural harbour first attracted the French explorer La Salle. He named the site "The Rapids" on 23 August 1679, when he had horses and men pull his 45-ton barque Le Griffon north against the nearly four-knot current of the St. Clair River.This was the first time that a vessel other than a canoe or other oar-powered vessel had sailed into Lake Huron, and La Salle's voyage was germinal in the development of commercial shipping on the Great Lakes. Located in the natural harbour, the Sarnia port remains an important centre for lake freighters and oceangoing ships carrying cargoes of grain and petroleum products. The natural port and the salt caverns that exist in the surrounding areas, together with the oil discovered in nearby Oil Springs in 1858, led to the dramatic growth of the petroleum industry in this area.

Because Oil Springs was the first place in Canada and North America to drill commercially for oil, the knowledge that was acquired there resulted in oil drillers from Sarnia travelling the world teaching other enterprises and nations how to drill for oil.The complex of refining and chemical companies is called Chemical Valley and located south of downtown Sarnia. In 2011 the city had the highest level of particulates air pollution of any Canadian city, but it has since dropped to rank 30th in this hazard. About 60 percent of the particulate matter comes from industries and polluters in the neighbouring United States.Lake Huron is cooler than the air in summer and warmer than the air in winter; therefore, it moderates Sarnia's humid continental climate, making temperature extremes of hot and cold less evident. In the winter, Sarnia occasionally experiences lake-effect snow from Arctic air blowing across the warmer waters of Lake Huron and condensing to form snow squalls over land.

Source: Wikipedia

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A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses.Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests. The South American savanna types cerrado sensu stricto and cerrado dense typically have densities of trees similar to or higher than that found in South American tropical forests, with savanna ranging from 800–3300 trees per hectare (trees/ha) and adjacent forests with 800–2000 trees/ha.

Similarly Guinean savanna has 129 trees/ha, compared to 103 for riparian forest, while Eastern Australian sclerophyll forests have average tree densities of approximately 100 per hectare, comparable to savannas in the same region.Savannas are also characterised by seasonal water availability, with the majority of rainfall confined to one season; they are associated with several types of biomes, and are frequently in a transitional zone between forest and desert or grassland. Savanna covers approximately 20% of the Earth's land area.

Source: Wikipedia