1 - A
sharp treeline formed by Nothofagus
sp. near Therma caliente, Chile, 1800 m
1 - A
sharp treeline formed by Nothofagus
sp. near Therma caliente, Chile, 1800 m
2 - The
Nothofagus menziesii treeline near
Haast Pass, South Island, New Zealand at 1200 m. This treeline does
not represent the life form's upper climatic limit: planted Pinus contorta grows well up to
1600 m elevation.
2 - The
Nothofagus menziesii treeline near
Haast Pass, South Island, New Zealand at 1200 m. This treeline does
not represent the life form's upper climatic limit: planted Pinus contorta grows well up to
1600 m elevation.
There is an upper elevational limit for any organism on the globe. For
some this is 300 m above the tropical sea level (coconut "treeline"),
for others it is the peak of Mt. Everest (some bacteria). Different species
reach different elevations in different parts of the world, some tree species
reach the upper climatic limit of the life form
tree. We call these treeline forming tree species. In some parts of
the world such species are missing (e.g. in Hawaii, New Zealand), hence, there
is no climatic "tree"-line (but still an upper climate driven limit of the
locally available tree species).
In other parts of the world "treeline species" are available, but trees
are absent because of
- shortage of moisture (arid regions)
- loose substrate (e.g. on volcanoes)
- fire or other disturbance (human land use)
Since these influences are not restricted to mountains, but can operate
anywhere, they are not of interest here.
3 - A
gradual treeline in the Alps, here on Mount Patscherkofel, Tyrol at
2000 m with Pinus
cembra.
3 - A
gradual treeline in the Alps, here on Mount Patscherkofel, Tyrol at
2000 m with Pinus
cembra.
4 - Not
too high for trees! This mountain semi-desert in Tenerife at 2600 m
(Canary Islands) is too dry for forest growth.
4 - Not
too high for trees! This mountain semi-desert in Tenerife at 2600 m
(Canary Islands) is too dry for forest growth.
Human land use
5 - Potato crops near the potential treeline in Ecuador,
3750 m.
5 - Potato crops near the potential treeline in Ecuador,
3750 m.
6 - Giant Espeletia rosettes instead
of montane forests, the long term consequence of land use and fire.
Páramos El Angel, Ecuador, 3600 m.
6 - Giant Espeletia rosettes instead
of montane forests, the long term consequence of land use and fire.
Páramos El Angel, Ecuador, 3600 m.
