If there are 600 pines, there are 20/100*600 = <<600*20/100=120>>120 more redwoods than pine trees in the national park.
In total, there are 120+600 = <<120+600=720>>720 redwoods in the national park.
Altogether, there are 720+600 = <<720+600=1320>>1320 pines and redwoods in the national park.
#### 1320