Managing Woody Encroachment

Loess Hills prairies, oak savannas, and oak woodlands were sunny, fire-adapted ecosystems prior to Euromerican settlement. Due to fire suppression, habitat fragmentation, and the extirpation of bison and elk, our native ecosystems have become dark; crowded with brush and an overabundance of trees. In many wooded areas the excessive shade has suppressed or eliminated much of the native sun-loving herbaceous plants that used to blanket the ground. 

Losing native plant communities to shade is a negative for biodiversity, water quality, and the land itself.

Without the herbaceous layer of plants on the woodland floor, water runs downhill unobstructed. Beyond that, the soil which the rainwater runs across is no longer held in place by the root systems of herbaceous plants. So instead of a filtering sponge, the woodland floor has become an erodible gutter. 

Brush Removal 

Physically cutting brush increases the amount of sunlight reaching the ground, promoting the growth of herbaceous plants. Removing brush also increases airflow, a necessity for the spread of beneficial fire. 

NAM often partners with the Omaha Zoo Browse Team who utilizes the brush we’ve cut to feed their giraffes, elephants, and rhinos at Omaha's Henry Doorly Zoo. 

Tree Clearing 

Physically felling all the trees of a given area. This practice is done in specific situations such as in the reconnection of generally treeless habitats like prairies. Much of the clearing work done by our NAM team takes place along old fence lines. Birds frequently visit fence lines and deliver seeds via their droppings. Given a few decades that fence line can become inundated with trees and brush creating a living fence between formerly connected sections of prairie.  

Fragmentation is highly disruptive to the function of prairie ecosystems. Wooded fence lines divide the prairie into disparate islands of life. Reconnecting our prairies is essential to restoring their ecological resilience and functionality. 

Tree Thinning 

The selective removal of certain trees in a given area. This practice increases the amount of sunlight reaching the woodland floor and reduces the competition for water and nutrient resources. Thinning increases the airflow of an area, allowing for improved spread of beneficial fire. Thinning can also reduce mesophication, a process that increases microclimatic humidity and the prevalence of fungal species which causes Bur Oak blight disease.