TABLE 1.

Land‐use system, age of modern human intervention, soil type, and soil category according to IUSS (2015) and location of the sites studied in three regions of Brazilian Amazonia

Region	State	Land use	Human intervention a	Soil type	Soil category	Coordinates
Iranduba	AM	Old forest	>20 years old	REF	Xanthic Dystric Acrisol	3°14′49.00″S, 60°13′30.71″W
		Old forest	>20 years old	ADE	Pretic Clayic Anthrosol	3°15′11.05″S, 60°13′45.03″W
		Young forest	<20 years old	REF	Xanthic Dystric Acrisol	3°13′34.47″S, 60°16′23.60″W
		Young forest	<20 years old	ADE	Pretic Clayic Anthrosol	3°13′49.23″S, 60°16′7.43″W
		Agricultural	Current	REF	Xanthic Dystric Acrisol	3°13′31.31″S, 60°16′29.18″W
		Agricultural	Current	ADE	Pretic Clayic Anthrosol	3°13′46.13″S, 60°16′7.32″W
Belterra	PA	Old forest	>20 years old	REF	Xanthic Dystric Ferralsol	2°47′4.59″S, 54°59′53.28″W
		Old forest	>20 years old	ADE	Pretic Clayic Anthrosol	2°47′3.25″S, 54°59′59.77″W
		Old forest	>20 years old	REF	Xanthic Dystric Acrisol	2°41′13.90″S, 54°55′3.30″W
		Old forest	>20 years old	ADE	Pretic Clayic Anthrosol	2°41′7.18″S, 54°55′7.11″W
		Agricultural	Current	REF	Xanthic Dystric Acrisol	2°41′3.56″S, 54°55′12.75″W
		Agricultural	Current	ADE	Pretic Clayic Anthrosol	2°41′3.79″S, 54°55′7.90″W
Porto Velho	RO	Young forest	<20 years old	REF	Xanthic Dystric Plinthosol	8°52′11.50″S, 64°03′18.16″W
		Young forest	<20 years old	ADE	Pretic Clayic Anthrosol	8°51′51.92″S, 64°03′48.03″W
		Young forest	<20 years old	REF	Xanthic Dystric Ferralsol	8°50′49.52″S, 64°03′59.20″W
		Young forest	<20 years old	ADE	Pretic Clayic Anthrosol	8°51′1.18″S, 64°04′3.07″W
		Agricultural	Current	REF	Xanthic Dystric Ferralsol	8°52′35.30″S, 64°03′58.58″W
		Agricultural	Current	ADE	Pretic Clayic Anthrosol	8°51′56.53″S, 64°03′40.67″W

Abbreviations: ADE, Amazonian Dark Earth; REF, reference soil.

^a Age of modern human disturbance (land management).