On the Mt. Lemmon Highway above the Rose Canyon Lake area is a small parking area on the right for the Green Mt. trail. The trail winds quickly up to a ridge then plunges down the north slope of the mountain. The ridge at about 7400′ is dry with sparse Ponderosa pine and some bushes among the rocks. No rain in March but still a bit of life. The ecology of the southwest mountains is a story of drought and fire, fire was wrongly suppressed for 100 years but has returned as mega fires. Global warming is predicted to warm Arizona by 10° C at least, so more fires, and the forests retreating up the mountains. After the Pleistocene Age ended the early Holocene had a period of global warming. The spruce forests in the southwest retreated and were lost to all the mountains save the Pinaleño Mts where the forests survived at the very top. Some spruce have returned to some of the higher Madrean peaks but this may be lost again.