Landslides

Acute soil loss, desertification

Virtually total forest destruction and massive vegetation losses in the first part of the XX century, and subsequent livestock management provoked erosion, soil slumping, wind erosion, topsoil wash off and general soil impoverishment in the region. As soil is the basis of the living matter of the biosphere and life starts in soil, the ecosystem could not recover.

In the PPAP:


Soil profile from a hill in the PPAP →  →   →

it  shows the layer of ash from fires of the last century.













From 1 to 2 m of topsoil were washed off from the hills as from the 1940s.

Like the region the area experienced acute soil loss, aggravated

by intensive strong winds in the valley, generated by the vicinity

of the Northern Patagonian ice field.


Burned (1940s) lengua tree : this tree did not grow on the rock, it’s roots are normally covered quite deeply by soil. As lenguas (Nothofagus pumilio) grow slowly, it must have been an ancient tree. At least 2,5 m of topsoil were lost in this case.


Approximately 1.3 x 107 tons (calculation very conservative for 1 m layer lost) of soil were washed off from the hills to the valley floor only in the PPAP.


Acute soil loss is visible on the hills, but not as bad as in other places of the region. Landslides, including large ones are common in the valley.  The reforestation programme is helping with controlling erosion.

Erosion pattern

The soil became an aggravated anthropogenic soil:

  compacted, low organic content, vulnerable to drought.

The soil lost it’s bacterial and microbiota

   component, and therefore its nutrient capacities.

There are virtually no earthworms in soil,

   their functions are partially replaced by ants, like in dry areas.

In winter the soil suffers from needle ice  →  →   →


Soil wash off changed the deltas of rivers and contours of

the lakes of the region. The delta of the largest river near

the PPAP, river Leones, was altered by the millions of tons of soil

the river carried.



Soil restoration actions:

☀︎ Nutrient immobilisation via first colonisers in reforestation.  

☀︎ Complete removal of cattle and reduction of the number of horses

to two led to elimination of soil microbiota deterioration by chemicals

(antibiotics, antiparasites, pesticides, etc.) used for them.

☀︎ Use of leaves mash for ice needles.

☀︎ Bacteria and microbes inoculation, using the science of

Metagenomics - the microbes run the world.

☀︎ Avoiding the use of dangerous herbicides for the control

of invasive species.

☀︎ Shift from farming animals to growing soil for nature.

The positive aspect: The land has no potential that is in competition with restoration and conservation: the soil is too poor and eroded for agriculture, grazing cattle or sheep is too damaging for the land;  there are no trekking possibilities.


Further reading on regional soils : in  Publications.

Forest fires Patagonia
Acute soil loss
Ice needles
Soil valley Leones
Soil Leones
Exposed rock Patagonia

PPAP: Bare rock -

result of soil loss

Delta Leones

Delta of Leones river

Exposed rock - result of soil loss

The PPAP: good example of destroyed ecosystem of the region and its inability to recuperate due to acute loss of soil  

Soil use
Acid soil
Soil class V
Soil class VI
Soil Leones valley
Ant

Ant

November 2018

Land use in the valley is use of soils of  VII - VIII national categories = use of dryland soils (de secano)

Soil use valley Leones

SINIA: soil use in the valley

SINIA