Why mountain soil is rich in humus?

Mountain soil is rich in humus due to several factors, including the abundant vegetation found in mountainous regions, which contributes organic matter through leaf litter and plant decay. The cooler temperatures and higher moisture levels in these areas slow down the decomposition process, allowing organic materials to accumulate. Additionally, the diverse plant species in mountainous ecosystems provide a variety of organic inputs, enhancing the soil's humus content. Together, these factors create a nutrient-rich environment that supports robust plant growth.