In the Western United States, shallow rocky soils and a dry climate often make it hard for new trees to grow in areas that have been harvested of older trees. Sometimes areas that have been harvested grow back quickly with other types of plants. These plants compete with young trees for moisture and nutrients. The scientists in this study wanted to test a different way of reducing the competition for soil nutrients and moisture. This is the Spanish-language version of the article. Topics: Active Forest Management, Competition, Fumigation, Fungi, Mycorrhiza, Native organisms, Reforestation, Soil.