The relationship between humans and the Amazon Rainforest has not always been a harmonious one. However, recent research suggests that the native peoples of the Putumayo region helped to protect the rainforest, leaving it unchanged for 5,000 years. Perhaps humans' coexisting with nature is possible after all.
The study, published in PNAS, looked at soil samples in the Putumayo region of the Amazon in Peru to find how humans influenced the land. The researchers found that the trees still growing in the region today have been growing there for the last 5,000 years — evidence that the area has not been home to cities and farmland in that time. Traces of charcoal (木炭) found in the, soil, however, indicate that people did live there; they just did so in a way that had minimum influence on their environment.
To come to these conclusions, the team dug a 0.6-0.9 meter deep column into the ground, taking samples of soil from different heights along the column. Back in the lab, samples were carbon- dated to determine their age and then sorted under a microscope to look for microscopic mineral particles, known as phytoliths (植硅体). Phytoliths are essential evidence of plants — they remained in the soil thousands of years after the plant died. So researchers can use them to tell which plants have grown in an area in the past.
Over 5,000 years' worth of samples, no species loss was detected. These findings suggest that contrary to common belief, the Amazon is not untouched by humans, but rather has been protected by them for thousands of years. The management of the rainforest by native peoples appears to have been vital in preserving its biodiversity and will continue to be important in the fight to prevent it from a collapse.
As Nigel Pitman, a co-author on the paper, said: "Since this particular forest is still being protected by native peoples, I hope this study reminds us all how important it is to support their work. "
