5 - HOW WAS THE EXPERIMENT CARRIED OUT?

Meetings were held with interested families in order to discuss the experiment.

The seedlings were produced in IBAMA in Rio Branco ...

 

... and taken to five family landholdings or sites.

 

WHERE WERE THE FAMILIES LOCATED?

Seringal São Miguel

Seringal Cachoeira

Seringal São José
- colocação Primavera - colocação Cachoeira - colocação São José
- colocação Três Barracas    
- colocação Cumarú    

WHERE WERE THE SEEDLINGS PLANTED?

At each landholding, seedlings were planted in:

  

Forest gaps

(where a tree had fallen)

  

shifting cultivation plots

(with rice and corn)

Pasture

(fences were constructed to protect

seedlings from domestic animals)

THE SEEDLINGS GREW AND WERE OBSERVED FOR TWO YEARS

Brazil nut seedling

The researchers

(Nazaré Macêdo e Karen Kainer)

WHERE DID THE PLANTS SURVIVE BEST?

Brazil nut survival differed a little in each landholding. For example, in São José, more seedlings died in the shifting cultivation plots and forest gaps. In Três Barracas, more seedlings died in forest gaps.

However, when taking into account all landholdings, there was no difference in Brazil nut seedling survival.

Shifting cultivation

plot

Pasture

Forest gap

After two years, a little more than half of the seedlings had died in all three areas with enrichment potential.

HOW WAS GROWTH?

The seedlings grew like this 
When they were planted, the seedlings were all the same size

After one year, they looked like this:

IN GENERAL, WHAT CAN WE OBSERVE?

Here are pictures of seedlings two years after they were planted:
Seedlings in shifting cultivation plots
are taller and thicker.

Seedlings in pasture
are thick, but not as thick as those in shifting cultivation plots. They are also the shortest seedlings of all.
Seedlings in forest gaps
are the thinnest ones. They are taller than those in pasture, but are also much shorter than those in shifting cultivation plots.

 

WHY WERE THERE GROWTH DIFFERENCES?

Soil

 

Here, soil is being dug up and taken to a laboratory for analysis. It is clear that shifting cultivation plots contain more nutrients than pastures or forest gaps. This is one of the reasons for good growth in shifting cultivation plots.
To test if the soil was compacted or not, this tool (auger) was used. Undoubtedly, the soil was more compacted in pasture, while that in forest gaps was the least compacted. Soil in the shifting cultivation plots, however, was also quite loose, favoring seedling growth.

 

Water

This instrument was used to test which of the areas had more water available for the seedlings to take up from the soil.

 

It was observed that forest gap seedlings became dry in midsummer. In the shifting cultivation plots and pasture, seedlings did not suffer any water stress.

WHY WERE THE FOREST SEEDLINGS DRY?

1 - Nightly dew did not reach the forest floor.

2 – Surrounding large trees competed for the water in the ground.

 

Sun

We used two different tools in order to test how the sun affected the seedlings.

This thermometer measured high and low temperatures. In Cachoeira, this kind of thermometer was placed in each of the three areas: shifting cultivation plots, pasture, and forest gaps. The results showed that heat was more intense in pasture and shifting cultivation plots, and less so in forest gaps

 

 This tool indicates the amount of sunlight each plant receives. The results showed that there was much less light in forest gaps

The test showed that young Brazil nut seedlings like a lot of light to grow. For this reason, the seedlings were thick in shifting cultivation plots and pasture, whereas in the forest, they were quite thin.

Animals

 

In the pasture, seedlings were attacked by sheep and cows, damaging plant growth. In some cases, the cow ripped the seedlings out of their planting holes.

Sheep

Cow

 

For this reason, construction of sturdy fences

was necessary.

 

There were also some problems with leaf-cutter ants that like to attack small plants.

 

However, in one of the pasture sites where there were neither sheep nor cows, the plants grew very well.

In shifting cultivation plots and forest gaps, we also observed that some other animals dug out some seedlings in search of food.

Agouti

Rat

Paca

 

WHAT ELSE WAS IMPORTANT FOR THE EXPERIMENT?

Weeding

The families had weeded shifting cultivation plots while growing rice, corn and beans, benefiting the Brazil nut seedlings. It was not necessary to do a lot of weeding in forest gaps. Weeding in pastures was much more labor-intensive.

Weeding must be done very carefully to not cut the seedlings.

Burning

Fire should never be set near the seedlings in either shifting cultivation plots, pasture, or forest gaps.

NO BURNING!

 

HOME

NEXT