A total of 1,854.7 hectares of Hustai National Park (HNP) is forested. The park’s forests are at the southern edge of the Siberian Taiga and are mostly (66.2 percent) birch and poplar with 23.6% being birch forests and 10.2 percent being poplar forests. The forests are found in moist areas and on the backside of mountains away from direct sunlight. In addition to birch and poplar trees, a few individual pine trees are also be found. Gobi Elm trees grow in abundance along the mountain gullies. A few elm trees grow in the sand dunes of Moltsog Els.
Since HNP’s creation in 1993, no forest fires have occurred. Nevertheless, the forests have been significantly degraded in recent years, most likely due to climate change. For example, 70 percent of the Khushuut Mountain forest has died. As a result, forest insect pests have increased substantially. Consequently, most of the trees in HNP have varying degrees of harmful insect infestations. This includes woody vegetation, such as the cotoneaster and ribes diacantha bushes, which have been damaged by moths. As a result of these challenges, pine and broad-leafed trees planted by the HNP Trust did not survive. In addition, while shrubs and bushes grow in high density along the Tuul River, they are being depleted as a result of local people cutting them for personal use.