Madrean Pine-Oak Woodlands

The Madrean Pine - Oak Woodlands ( Madrean pine - oak forests) are subtropical forests in the mountains of Mexico and the southwestern United States. They are the dominant vegetation type in the high altitudes of all Mexican mountain ranges. Other deposits are found in Arizona, New Mexico and Texas. The Madrean Pine - Oak Woodlands are counted from Conservation International to the most threatened biodiversity hotspots. The name comes from the Spanish word Sierra Madre ( Mother Mountain ) for all major mountain ranges of Mexico.

Ecosystem

The Madrean pine - oak forests are made up as the name suggests largely of pine and oak trees together. Other tree species are spruce and Douglas fir. In the forests there are 44 of the world's 110 species of pine and oak trees, with over 135 species more than 30 % of the world's biodiversity. The other flora is not even recorded approximately, it is estimated that over 5300 species, of which 70 % are likely to be endemic. The character of the forests ranges from loose, dominated by oak trees in a savannah -like landscape to the dense pine forest with canopy. In particular, the loose forests are adapted to specific dimensions to the environmental factor fire, they are dependent on that sporadic fires of natural origin to keep open the landscape and prevent encroachment.

The fauna of the forests is diverse. It is composed of a wide variety of around 200 amphibians and reptiles about 380. About 520 bird species have been determined, and more than 330 mammals. Furthermore, around 80 fish species were recorded. The number of invertebrates can not even estimate approximate.

Proliferation and threat

The original extent of the Madrean Pine - Oak Woodlands is determined on over 450,000 km ², of which at the beginning of the 21st century still approximately 92,000 km ² to receive. The biggest threat is the direct deforestation by forestry. Other factors include the urban sprawl of the hill regions in the vicinity of cities and the suppression of forest fires. Pull over decades no fire through the ecosystem, the semi-open forests transform into dense stands where conifers dominate. This effect is particularly occurred in the United States thanks to the substantial suppression of forest fires between 1930 and 1980/90er years. Only since the end of the 20th century recognized to the importance of forest fires for many ecosystems adapted to it. On the other hand destroyed intense burning of vegetation for the purpose of soil fertilization for cattle farming ecosystem immediate and lasting. Other human influences are the intense Absammeln of fungi as delicacies and the removal of Tillandsia as a houseplant and as popular in the region Christmas decorations.