Most of the planet's ecosystems have been degraded in some way by human encroachment. Everyone is so focused on the Amazon rainforest, the Great Barrier Reef, or hundreds of other amazing and beautiful places that they overlook the many deserts around the world that are also in the same condition. Whether it's the Mojave, the Sahara, the Gobi, or one of the other lesser-known deserts around the world, many of them are in a state of decline. This, combined with the harsh, nutrient-poor conditions in deserts, can slow the system's natural return. Therefore, many studies and efforts have been made to accelerate this process and what is needed. Restoring desert ecosystems around the world requires attention to soil nutrients and retention, the needs and interactions of local flora, and the restoration of native fauna. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original EssayWhat caused deserts like the Mojave to degrade? As in many other places, human development is the root cause of this problem: farming, ranching, mining and other activities that deprive the land of habitat for profit. Of these, the most harmful and widespread cause of habitat destruction is overgrazing of the territory by livestock. According to Robert Webb and Steven Stielstra (1979), livestock consume plants and trample on others, creating more disturbance than the ecosystem can handle. After a century this has left these ecosystems barren, with studies showing that this decrease in vegetation cover leads to a sharp increase in erosion and runoff (Webb & Steven 1979). After all this damage there is a lot of work to do, so it helps to know where to start. So, let's start from scratch, with almost any restoration effort, one of the first things you need to do is look at the contents of the soil. You need to know what can grow where and if there are any deficiencies that need to be addressed before you can start planting. As you might imagine, desert soils tend to be sandier and nutrient-poor. In the Encyclopedia of Soils in the Environment, the World Soil Map section by H. Eswaran and P. F. Reich (2005) examines the two main types of soil found in arid regions of the world, namely Entisols and Aridisols. Entisols are soils with no significant formation and are commonly found in highly eroded areas of the world. Because they are constantly being eroded, they lack the superior, more nutrient-rich organic topsoil and are very mineral in nature. Because of this broad classification there are several subcategories of Entisols with the desert variety being Psamment. Which is largely made up of the quicksand that make up the shifting dunes that populate desert regions. In the same section of Eswaran and Reich (2005) it is explained that aridisols have stratification and some nutrients but lack adequate hydration. As such, these arid soils are unable to support all but the most adapted plant life, as according to the text there is no time of year when there is sufficient soil hydration to allow 3 months of continuous growth. This also leads to another problem with Aridisols which make growth difficult for most plants as they also tend to contain a build up of salts which then get redistributed across the horizons. Despite the water-soluble nature of these salts, the lack of precipitation keeps the soil very alkaline (Eswaran, Reich 2005). However, despite the quality of the soil, many plants such as cacti, legumes and trees with deep roots call thishome ecosystem and is where many restoration efforts are focused. Due to the arid and changing nature of the soil and the slow plant growth that results from it there are many challenges that must be overcome. One of the biggest problems with desert degradation around the world is that when plant life is destroyed or overexploited, it can no longer hold the sand on which it resides. This then leads to many problems, such as the increase in the frequency and severity of sand and dust storms or the onslaught of desertification. Desertification is the degradation of “dry arid, semi-arid and sub-humid areas” most often caused by human activities such as overgrazing of livestock (Li, Y. 2009). For this reason, restoring a desert often involves finding ways to maintain soil retention. In a research paper by Li, chessboard across a degraded desert landscape. The straw serves as makeshift foliage and maintains desert soil retention long enough for desert plants to grow and set the soil in place. The process involves the installation of “mechanical sand fences” created from bamboo and willow to act as windbreaks. After that, wheat straw, which can be purchased cheaply in large quantities, is placed in the ground in such a way that it partially sticks out in a checkerboard pattern. Next, native xerophytic shrubs are planted in the 1 meter by 1 meter squares. Due to the arid nature of the environment and lack of rainfall, these structures can remain functional for up to 5 years, giving plants sufficient time to develop. Knowing this, the group of researchers led by Li, XR (2006) then set out with their own study to test this procedure for themselves. They set up 4 test sites and used a variety of shrubs and grasses in checkerboards or “squares” for a total of 120 plots. They then took soil samples, measured dust deposition along the checkerboards, and observed bulk density and pH levels throughout the study. After 6 years the research was concluded and it was found that the use of straw checkerboards before planting native xerophytes led to an increase in the overall increase in species richness, ground cover, dust deposition and of the accumulation of silt and clay in the soil. This has proven to be an effective method in desert restoration of areas that have lost sand-binding plant cover. But what do you do if there aren't enough nutrients or water to go around, or if the plants you're introducing have problems? put down roots and establish yourself? Restoring desert ecosystems can be a difficult undertaking for these reasons. Even in restoration to temperate, more nutrient-rich climates transplanting can lead to failure of some plants. This is exasperated in the extreme conditions found in deserts, even more so in the degraded ecosystems that are being attempted to restore. Transplant survival under these conditions can be as low as 25% or even worse if herbivorous animals are in overabundance (Abella et al. 2015). Therefore, this must be at the forefront of any restoration effort in revegetation of the site. How can this problem be circumvented? An experiment by Scott R. Abella, Lindsay P. Chiquoine, Alice C. Newton, and Cheryl H. Vanier for the Journal of Arid Environments v115 (2015) examined solutions to this problem. They looked at rooting hormones, nutrient-rich slurries, soaking treatments, watering and potting soil replacement between 23different species of plants. The young plants were grown in the nursery where they were monitored before being subjected to the various treatments. They found that IBA rooting hormone, soaking and slurry treatments did not increase survival in or out of the nursery. Replacing the topsoil fared much better, as it increased plant survival to 56%, compared to the original 25%. However, irrigation has proven successful, increasing plant survival by up to an average of 65%. This information is valuable for understanding what to do and what not to do in restoring this type of ecosystem not only to increase plant survival, but also to avoid unnecessary expenses. Some plants, however, are much more particular about where they can grow, and this can lead to new challenges in trying to recreate these conditions. Research by Bacilio, M., Hernandez, J.P., and Bashan, Y. (2006) from the journal Biology and Fertility of Soils, 43(1) examined the Cardon Cactus, an important plant crucial to restoration in the Sonoran Desert that it was largely removed for land development. The cactus is largely found in areas with higher soil fertility and nutrients nicknamed “resource islands.” Since these were not always available, they looked at the effects of compost and the growth-promoting bacterium Azospirillum brasilense to stimulate growth instead. They found that while the bacterium did little to increase the growth of the cacti, the compost performed better. Compost, added at ratios ranging from 6% to 25%, simulated the “resource island” soil favored by the cactus and resulted in increased growth. This demonstrates that soil variations such as “resource islands” can be artificially recreated in the context of restoration. However, if you wanted to recreate these conditions naturally, as restorationists often do, how would you do it? Deserts, being by nature very poor in nutrients, often depend on the biotic interactions of plants and animals, including legumes. In Desert Restoration: The Role of Woody Legumes by Ross A. Virginia (1990) he traces the important role played by woody legumes such as the mequite (Prosopis glandulosa), the smoke tree (Psorothamnes spinosus), the palo verde (Cercidium floridum ) and others. The most important role they play is as major nitrogen fixers in the Sonoran and Chihuahuan deserts. They are important for increasing soil nutrients and “resource islands” important to the ecosystem (Virginia, R. 1990). Ross explains that as trees grow, they develop deep root systems with nitrogen-fixing bacteria increasing soil fertility. During this development, legumes periodically lose their leaves which then decompose. This decomposition releases all the nutrients and cations that the tree has absorbed from deep within the soil and deposits them on the surface creating rich topsoil. Over time this changes the chemical and physical properties of the soil creating “islands of resources” on which the Cardon Cactus and other key species rely. Despite their importance, Ross explains that getting trees to reproduce and become established can be difficult and time-consuming. To properly establish their deep root system requires a level of stored soil moisture that occurs naturally only once or twice every decade. This can be aided by restoration practices such as “deep ripping or 10-foot-deep augur holes” to improve water filtration. So, we talked about soil types, soil fixation, and soil nutrients, as well as the steps needed to introduce native plant species. . Naturally,all this development not only benefits native vegetation, but also invasive species. The bane of any restoration project is dealing with the invasion of overly aggressive non-native plants and animals that devastate what you have painstakingly restored. Of course, the normal procedure would be to mow and spray regularly to keep them at bay. While it definitely works, it can take a lot of time and work. To reduce the impact of invasive species and the need for spraying, some researchers have examined the use of native species to keep them at bay (Abella, et al. 2012). In a study by Scott Abella, Donovan Craig, Stanley Smith, and Alice Newton (2012) examined native plant species and whether they could be used to reduce the number of invasive species present in the restored ecosystem. The most common type of invasive species in desert ecosystems are prairie grasses. Many of them spread after the rainy season and dry out in summer, causing rare fires in this region. This fire then destroys the slow-growing native populations while the grasses, which are simple, pyrophytes, reappear in a vicious cycle. Some of these invasive grasses they examined controlled where Bromus rubens (red brome) and the exotic Mediterranean grasses Schismus arabicus and barbatus. The study itself (2012) focused on sampling methods for native plants to find out which species are effective in invasive reduction. They looked at several species of varying growth and aggressiveness, from early herbs and flowers to late shrubs. They found that planting communities of early seasonal flowers, particularly the species Sphaeralcea ambigua, also known as desert mallow, did best at competing with the invasive species. Other species did not fare as well and ended up losing ground. They also assessed nitrogen levels and how this affected the spread of invasives, finding that increases in one led to significant increases in the other (Abella, SR, et al 2012). Two things can be gleaned from this. The first is that when trying to restore an ecosystem it can be useful to find more natural solutions or aids to problems. Secondly, it touches on the potential harmful effects of introducing the nutrients we talked about earlier. Continuing on the same theme, restoring desert ecosystems can sometimes have a unique benefit. Because deserts are very inhospitable and extreme environments, sometimes the best thing you can do to drive out invasive and exotic species is to restore the habitat. The degradation and change of the environment from its initial state may be what allowed non-native species to thrive and become invasive in the first place. At Ash Meadows National Wildlife Refuge, which is located in an oasis region in the Mojave Desert, they had problems with invasive fish. Chemical and physical solutions have proven to have limited success and therefore attempts have been made to adopt other solutions like this (Scoppettone, et al. 2005). The study was conducted by Gary Scoppettone, Peter Rissler, Chad Gourley, and Cynthia Martinez (2005) and looked at a part of the preserve that had over time become a cold-water marsh. This was because in the past large concrete levees and ditches were installed to divert water from hot springs for agriculture. This change in the environment then allowed the invasive species Gambusia affinis (mosquito) and Poecilia latipinna (sailfin molly) to overwhelm local fish populations. After diverting the thermal water back into the swamp, increasing the water temperature to a range of 18 – 32°C and altering the flow velocity to 30 cm/s, changes occurred.