Like many other parts of Nebraska, the Niobrara is poised to suffer significantly in the face of a rapidly changing climate. Due to increased greenhouse gas emissions, most of Nebraska is expected to warm significantly, in the range of 4 to 9 degrees Fahrenheit by 2100. This small shift in temperature will have drastic impacts on the climate of Nebraska and the Niobrara River Valley.
Decreased Soil Moisture
While the Sandhills are an exceptional natural feature of north-central Nebraska, an even further decrease in soil moisture from an increased temperature will cause massive strain on local ecology and the agricultural industry. Farmers will be forced to rely more heavily on our massive underground aquifers, steadily increasing the rate at which they are depleted. Simultaneously, a general decrease in inches of precipitation per year will slow replenishment of groundwater sources.
Additionally, the Niobrara itself is fed primarily by spring water originating from these groundwater sources. Stress on the process of recycling this water via precipitation poses a threat to the river itself, and in combination with more frequent and severe drought, the Niobrara could risk dangerously low water levels, levels much too low for visitors to enjoy or wildlife to rely on.
Increased Frequency of Extreme Weather Events
Typically, when forecasters predict heavy rainfall in an area affected by drought, some get excited at the prospect of moisture, either for crops, local water levels, or maybe just their front lawn. Unfortunately, for those familiar with cycles of drought and rainfall, increased precipitation can be a double-edged sword.
Drier soil is often less absorbent than moist soil, leading to exceptional runoff during heavy precipitation in the middle of a drought. This runoff can in turn cause massive flooding, threatening the safety of Nebraska’s towns, cities, and farmland. In the future, Nebraska will see its wettest days get even wetter, meaning alongside increased frequency of drought, we will see flooding becoming more frequent along the Niobrara.
Simultaneously, wildfires are likely to become more common in Nebraska thanks to more difficult drought cycles. Ice jams and mid-winter ice break-ups, which can also cause massive flooding and damage to our river ecosystems, will also occur more frequently due to higher temperatures in the winter, lowering overall ice thickness and resiliency. Research is currently ongoing for the risk of tornadoes in the face of a changing climate, and a consensus has yet to be reached. However, what we do know is that an increase in ambient temperature will cause widespread issues for the industries of Nebraska, the lives of its citizens, and its precious natural resources.
Strain on Niobrara’s Unique Ecosystems
The Niobrara Valley supports various unique and diverse ecosystems, thanks in part to the microclimates formed by the topography of the valley itself, allowing many species to thrive far outside their typical range. This species diversity is one of the Niobrara’s most recognizable features, and sadly, one of the many things threatened by a changing climate.
For example, the paper birch, which usually populates northern boreal forests, has founded quite a stock here along the Niobrara. Unfortunately, steady die-backs of mature trees have been observed without ample replacement by young saplings. These birch trees have difficulty maintaining consistent reproductive populations in areas where July temperatures exceed 70 degrees Fahrenheit, a real possibility for a Nebraska affected by climate change.
Additionally, compared to the vigorous Eastern Red Cedar, which has a tendency to overstay its welcome here on the river, paper birch trees provide many essential nutrients to the forest floor, with high levels of potassium, phosphorus, and calcium being found in paper birch leaf litter. Thanks to these soil-enriching properties, these trees establish themselves not just as a unique example of the Niobrara River Valley’s extraordinary diversity, but also as a productive member of the local environment. In simpler terms, this species is one worth saving.
Below is a video going into further detail about the exceptional potential of the Niobrara to shelter a wide range of local species, some being hybrids not found in many other places in the world.
Local residents and NPS staff have long thought that the aspens found here (200 miles from any other naturally occurring aspens) are pretty special. This video shares the results of a new study, which clarifies just how special these unique hybrid trees actually are.