After the boom-bust-boom of the fifties and sixties, the borough went into a third and more severe decline again in the mid-1970s along with much of the Rust Belt so that population was just 2,804 at the 2000 census. Now in the 2011 Brownsville still has a handful of buildings condemened or just borded up.
One threat to these Savanna biomes is the animals which graze upon it. Other biomes such as Taiga or Rainforest have a high tree quantity which means that less grass is able to grow for animals to graze on. However, since Savannas have few trees and much wide open space than other biomes an herbaceous layer grows much easier.
Savannas, characterized by a grassy prairie-type ground cover underneath an open tree canopy, were common in northeastern Illinois. Scattered out on the prairie were patches of rich forests completely surrounded by prairie; these forests are called prairie groves.Prairies developed and were maintained under the influence of three major non-biological stresses: climate, grazing, and fire.Occurring in the central part of North America, prairies are subject to extreme ranges of temperatures, with hot summers and cold winters.cattered out on the prairie were patches of rich forests completely surrounded by prairie; these forests are called prairie groves. Prairies developed and were maintained under the influence of three major non-biological stresses: climate, grazing, and fire.