Most landscapes in the Austin area can be described as the sunny edge ecological condition. Each day, the sunny edge landscape zone changes from shady to sunny, or vice versa, as the sun moves across the sky from morning to evening. Shading can be produced by either trees or urban structures to reenact the classic savanna condition, which prevails across the Texas Hill Country within the Edwards Plateau region.

edge effect

In ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats, Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity. — wikipedia


The sunny edge can be described in a few different ways, so here are a few of our favorites:

  • savanna
  • open-canopy woodland
  • mixed woodland grassland ecosystem
  • broken woodland
  • barrens
fire ecology

Before the arrival of Europeans in this part of Texas, Native Americans maintained the balance of trees + grass using controlled wildfires. The sunny edge condition that this management style encouraged was nurtured herbaceous grazers + facilitated hunting.  Learn more about this at wikipedia.


A savanna is described as a ”broken woodland,” which means groupings of trees separated by open sky gaps. The shade created by the trees helps protect a biodiverse community of grasses, forbs and understory shrubs growing below from the full force of the sun, but is usually not so dense that the area below is completely shaded-out.