Complex sentence: Summerlin is an affluent neighborhood in the western area of Las Vegas, which will be affected through property values and upscale quality of life issues, in addition to the stress on the Red Rock Canyon National Conservation Area ecology.
Split into simpler sentences: Summerlin is an affluent neighborhood in the western area of Las Vegas. Possible obstacles are the effects on property values and quality of life, in addition to potential stress on the Red Rock Canyon National Conservation Area ecology.