User:Smallchief/Manso River

Description

Rather than being a single coherent range, the Davis Mountains are an irregular jumble of isolated peaks and ridges separated by flat areas. The mountains occupy a rough square about 50 kilometres (31 mi) on each side with elevations above 1,500 metres (4,900 ft). The mountains are of volcanic origin composed of strata associated with eruptions of the Trans-Pecos Texas volcanic field 35 million years ago. The highest peak in the Davis Mountains is Mount Livermore at 2,555 metres (8,383 ft), and is the fourth highest peak in Texas.

Vegetation

The Davis Mountains are a sky island, an isolated mountain range surrounded by desert. The town of Fort Davis at the foot of the Davis Mountains has an elevation of 1,500 metres (4,900 ft). From that elevation the sky island rises to 2,555 metres (8,383 ft). As the elevation increases, average temperatures decline and precipitation increases permitting an "island" of forest and other mesic habitat at higher elevations.

The McDonald Observatory is situated at an elevation of 2,070 metres (6,790 ft)

The higher, cooler elevations of the one of many in west Texas, New Mexico, Arizona, and northern Mexico. , and includes montane grasslands, pine-oak woodlands and isolated stands of ponderosa pine forest at higher elevations.

The most common vegetation of the Davis Mountains is montane grassland, often mixed with scattered bushes and trees. As is common in most northern hemisphere semi-arid climates the vegetation on the southern slopes of the mountains is noticeably sparser than on the northern slopes. This is due to the greater exposure to the sun on southern slopes and, thus, warmer temperatures and drier soils.

Mixed in with the grassland, and usually at higher elevations, are four woodland and forest zones in the Davis Mountains. First, found at elevations below 1,900 metres (6,200 ft) and at higher, drier elevations the dominate tree species is the alligator juniper mixed with oak species and pinyon pine. Secondly, woodlands with Pinyon pine as the most common species are found on steep slopes at elevations of 1,750 metres (5,740 ft) to 2,400 metres (7,900 ft). Third, woodlands in which the gray oak is the most common tree and mixed with other oak species are also found on steep slopes at elevations of 1,900 metres (6,200 ft) to 2,400 metres (7,900 ft).

The richest and most diverse of the woodlands and forests in the Davis Mountains are the mesic forests found from 1,770 metres (5,810 ft) to 2,330 metres (7,640 ft). These forests are found in stream valleys and other well-watered areas. Indicator species are ponderosa pine and southwestern white pine, plus a small number of quaking aspen trees which are more characteristic of the higher elevations in the Rocky Mountains. The mesic woodlands are remnants of past glacial ages in which the climate of west Texas was more humid and cooler than at present.