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.
A savanna or savannah is a grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close.ometimes midwestern savanna were described as grassland with trees. Different authors have defined the lower limits of savanna tree coverage as 5â10% and upper limits range as 25â80% of an area. Two factors common to all savanna environments are rainfall variations from year to year, and dry season wildfires.