Biology - It Grows on You. : A Trip to the Desert: Biome Activity

I recently embarked on an adventure, curious to learn more about biomes on earth. Because I can't stand rain, and I really hate the cold, the rainforest and tundras were immediately ruled out. Eventually I decided that the desert and xeric shrub-land regions were my only option. With my mind set on a destination, my journey began. 




Knowing only minimal information about the desert (basically only knew that it's hot) I began researching about this environment to better understand what I was getting myself into. 






With more research now being acquired, picking a definite region to travel to experience the biome was difficult. I never realized how many options there were to visit a xeric shrub-land in the world!  It is the largest terrestrial biome, responsible for covering about 19% of the earth's land surface area.


Photo Courtesy of WWF

Worldwide, these desert shrub-lands can vary vastly in the amount of rainfall in which they receive. The evaporation in the regions exceeds the rainfall by a landslide, allowing for only about 10 inches of rainfall annually. The temperatures in these regions also vary greatly. Some regions, such as the Gobi in Asia, become quite cold in the winter and temperatures drop drastically, whereas other deserts, such as the Sahara, stay sweltering hot year-round. 



If you compare the temperature vs. precipitation graphs of the two deserts mentioned above, it is clear to see their climate differences! The Saharan desert's temperatures do not drop as much, or have as large of a temperature high and low as in the Gobi desert.

The Temperature and Precipitation Graph of the Gobi Desert in Asia
The Temperature and Precipitation Graph of the Saharan Desert

All those hot temperatures probably have to do with the great amounts of bright sunlight that the desert regions receive. When comparing the map of xeric shrub-lands in the world to the map of solar radiation, the most intense regions match up with some type of a desert, Saharan type of area. You can see many of the desert regions can receive over 3000 hours of bright sunshine, per year! I might want to bring some sunglasses...



With all these extremely hot temperatures, and almost non-existent rainfall, I wondered if life could really exist in these regions. Is it possible to have an extensive ecosystem full of various species and plant-life when it's just so hot?


Photo Courtesy of Green Tech
I first did a little research about the soil and earth that makes up these deserts. I learned that b ecause biomass productivity is low, the litter layer is almost nonexistent and organic content of surface soil layers is very low. Not only that, the evaporation that the desert experiences causes a strong concentration of salts on the top layers of the surface. 

So far, I wasn't convinced there could be life yet in these vast, hot, sand-lands. 


Photo Courtesy of Citadel
Since the ecosystem and climate is very unique and specific, only certain plants can survive. The main producer in the desert ecosystem is the cactus! The cactus acts a primary source and the beginning of the food chain for the consumers, and then later on, the decomposers. Let me tell you, the desert is FULL of plant and animal life. Here are just some of the common cacti you might find in a desert region.


It's a dog-eat-dog world out there, and the desert isn't excluded from this at all. These cacti, or producers, act as a feeding source for the consumers. The most common desert consumers include insects, rats, lizards, quails, deers and other grazers. While secondary desert consumers include small and large predators such as snakes, hawks, and coyotes. These consumers feed off of plants such as producers, and can sometimes feed off of other consumers as well. The decomposers come later on in the cycle and usually feed off of dead animals and help break them down, or, decompose them. Decomposers may include, bacteria, worms, or fungi, that eat things usually none of the other animals in the ecosystem might.  

However, it's not as dark and grim as it seems! A lot of these species share symbiotic relationships. A symbiotic relationship  is one in which two organisms equally benefit from each other through a series of events or actions. An example might be a bee pollenating the flowers of a cactus, allowing not only the bee to benefit and do what it needs to, but helping the cactus as well the grow and reproduce.

Photo Courtesy of Green Acres Ranch



This bustling eco-system is rich with different plant and animal species. Unfortunately, disturbances to their environment can cause difficulties or even eradication to the different dwellers of the desert. Humans are typically the most responsible in the destruction or interference of this ecosystem.
One of the most prevalent issues concerning the desert today is the impact of global warming (for more information check out the link). The climate changes cause all sorts of disturbances in the habitat, such as more incidences of droughts which dry up water holes in the already barren desert. This can and does impact species severely. Also, the higher temperatures allow for wildfires more easily which can alter and destroy desert landscapes and shelters needed by the dwellers. Other dangers include irrigation created by farmers, which can eventually lead to higher salt levels in the soil, which will then not be able to support as much, or any, plant life. For a more extensive outlook on the dangers, refer to this great article by National Geographic.

With all these harsh climates, and human influence, it must be difficult for species to survive. However, most of these organisms have undergone specific mutations and adaptations which allow them to be better suited for the climate and environment. They have overcome barriers which the natural habitat has presented to them by finding unique ways to survive:


Courtesy of Living Desert


With all this information down and my newly acquired knowledge, I think I'm finally ready to face the desert and xeric shrub-lands! I know it won't be easy, but I know what I'm coming up against. I'll be sure to pack a lot of sunscreen, water, and light clothing for this trip. Stay tuned for my biome journey!

If you're interested in learning some more, or just summing my blog post briefly, here are some very informative videos courtesy of National Geographic.





Sources:

http://www.livingdesert.org/desert_animals.html
http://resources.woodlands-junior.kent.sch.uk/homework/adaptations/desert.htm
https://www.youtube.com/
http://www.blueplanetbiomes.org/desert_animal_page.htm
http://www.desertusa.com/desert-food-chain/food-chain-2.html
http://citadel.sjfc.edu/students/naa07113/e-port/decomposers.html
http://en.wikipedia.org/wiki/Deserts_and_xeric_shrublands
http://wwf.panda.org/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat13.cfm
http://environment.nationalgeographic.com/environment/habitats/desert-map/
http://www.eoearth.org/view/article/177257/