Geog101 Introduction To Geography : Assessment Answers

Answer:

Desertification is the degradation of land usually in dry areas triggered by a variety of factors such ranging from climatic changes and human activities, as defined by the United Nations. Desertification affects more than one billion people around the globe who depend on the dry land ecosystem as a source of their livelihood (Earth Observatory). 52 percent of land utilized for farming has been relatively or extensively affected. Arid lands in parts of North America are some of the areas badly affected by desertification.

The Sand Hills region in western Nebraska is one of the areas in the United States affected by desertification. It is the biggest active dune field in the Western Hemisphere, with dunes as long as 20 miles long and 400 feet high. These dunes go back to the Pleistocene Epoch (geologic period ranging between 10,000 to 1.8 million years ago), (NASA TV). Wind-blown sands from the Rocky Mountains formed the dunes by Pleistocene glaciers. The Sand Hills are usually regarded as a semi-arid region where faint precipitation, sandy soils and soaring rates of evaporation hold up dry grassland. Water from the ground resulted to wetlands and springs in the dale between the dunes. Vegetation in the Sand Hills is the main aspect that plays a part in the solidity of the dunes. There are over 720 plant species estimated to be growing in the Sand Hills without cultivation. Reactivation of the sand dunes would result to possible repercussions such as ruination of grazing land, transportation paths, fertile cultivated land and desolation of wetlands that would greatly affect wildlife. Grassland covers more than 95% of the dunes at the moment, (U.S. Geological Survey Programs in Nebraska ). The Sand Hills are mainly used for grazing, as crop agriculture has not born any fruits in the past due to the sandy soils.

The Sand Hills is currently in danger due to climate change. Scientists believe that average temperatures will rise over the next century. According to climate experts at the University of Nebraska, there will be less precipitation, but storms will be graver on occurrence with high possibilities of washouts and floods, (Eckel). The floods will possibly destroy roosting areas of the whooping cranes that migrate from Texas to Nebraska in spring and fall. This will naturally lead to a decline in the number of birds migrating that play a vital role in the ecosystem of the Sand Hills.

As from the early 1900s, landowners drained numerous wetlands to allow cutting of hay which was needed by their cattle especially during winter. This, in turn, ruined the cushioning function of the wetlands as water went to the streams instead of being taken in by wetlands as before. According to scientists, the proposed scientific reason for the desertification taking place here was this, (Herrmann). Over the years, it has gone through several changes as a result of the sparseness of vegetation and high risk of soil erosion. Additionally, row crop agriculture has also contributed to the desertification of the Sand Hills. Nevertheless, current irrigation has prompted the formation of wet regions by dint of pumping water from the ground.  

Various measures are being taken to combat with the desertification process taking place in Nebraska. One of the ideas suggested is Holistic Management. This approach involves using cattle as if they were the herds of herbivores and looking after them based on a planned program. The approach, being practiced in around 40 million acres across the world, was invented by Allan Savory – an African rancher and established in 1992 on a ranch in Zimbabwe, (Schwartz). This idea has the capability to revitalize huge pieces of grasslands so long as landowners dedicate themselves to leave their past ranching practices. There before, grasslands were blooming prior to the adoption of current ranching methods. This was because of large herds of herbivores that wandered across the terrain reinvigorating it, taking small bites from plants thus promoting root growth, and treading on the earth allowing proper germination of seeds and fertilization of the ground with their dung.

The fencing of grasslands has hampered all of these processes. This idea has received a good reception and is now making substantial progress in the United States. Environmentalists agree that Holistic Management is a formidable tool capable of reversing the destructions humans have imposed on Sand Hills. Apart from reclamation of the grassland, Holistic Management absorbs extra carbon from the atmosphere thereby keeping the soil fertile and reducing climate change. Desertification is severely affecting the world. It's high time that humans joined hands to combat this menace that is threatening to ruin the environment for future generations.

Reference:

Earth Observatory. 21 April 2017 <https://earthobservatory.nasa.gov/Features/Desertification/desertification2.php>.

Eckel, Emily. Newsnet Nebraska. 21 April 2017 <https://projects.newsnetnebraska.org/climate-change/sandhills/>.

Herrmann, S., and Hutchinson, C. "The changing contexts of the desertification debate." Journal of arid developments 63 (2005): 538-555.

NASA TV. Ed. NASA Administrator. 23 March 2008. 21 April 2017 <https://www.nasa.gov/multimedia/imagegallery/image_feature_465.html>.

Schwartz, Judith D. The Christian Science Monitor. 24 October 2011. 21 April 2017 <https://www.google.com/amp/www.csmonitor.com/layout/set/amphtml/Environment/2011/1024/Saving-US-grasslands-a-bid-to-turn-back-the-clock-on-desertification>.

U.S. Geological Survey Programs in Nebraska. 21 April 2017 <https://pubs.usgs.gov/fs/FS-025-96/>.