The desert dominates the landscape: What can be done?

A new study analyzes satellite images of the state of the vegetation in the northern Negev in areas that may become a desert. The conclusion: there is hope, small dams that catch rainwater create life around them and can prevent the desertification process

By Tomer Atir, Angle - Science and Environment News Agency

The secret of the desert's beauty, the little prince stated, is the water that hides in it: water is also the secret ingredient in the functional restoration of degraded areas. A pool in the Ein Gedi area. Illustration: depositphotos.com
The secret of the desert's beauty, the little prince stated, is the water that hides in it: water is also the secret ingredient in the functional restoration of degraded areas. A pool in the Ein Gedi area. Illustration: depositphotos.com

Do you also like to walk in the desert? Enjoying the view, the silence, the sands and the unique rocks? It may be that the climate crisis will "fix" more desert areas in Israel for you to travel through. With the warming of the earth, the lack of precipitation and the increase in the rate of evaporation - there is a danger that the desert will expand. The Negev and the Arabah, which make up about half of the country's territory, are arid or semi-arid areas where the average annual precipitation is less than 250 mm. These areas are exposed to the desertification process. The desert creates "conditions that keep getting worse" in ecosystems, says Gil Siaki, director of the forest department in the southern region of the Kimat Israel Foundation. In the northern Negev, he points out, desertification processes are evident and the ecological systems are deteriorating - the lands are no longer fertile, the biological diversity is damaged, the ability of the land to regulate floods is decreasing and the supply of food for grazing is dwindling. Therefore, stopping desertification has a great contribution to the environment.

Yes to the desert, no to the desert

To prevent desertification on the edges of arid areas, you can plant trees and thus enjoy benefits such as stopping soil erosion as a result of floods, creating a shaded environment and fixing carbon - a process in which free carbon dioxide in the atmosphere turns into plant organic matter and reduces the concentration of carbon dioxide in the atmosphere. On the other hand, in an area that has already undergone desertification, the treatment is mandatory Functional rehabilitation of the desert area and turning it into a functioning ecosystem where the soil is fertile and stable - and not washed away by floods, and that the system can operate properly and deal with disturbances such as climate change and a lack of precipitation.

The secret of the desert's beauty, the little prince stated, is the water that hides in it: water is also the secret ingredient in the functional restoration of degraded areas. The basis for the restoration of the system is the management of the runoff water - the rainwater that flows on the surface of the ground and does not seep into it, and that regulates the water in the area. In rehabilitated land, in contrast to desertified land, the runoff water is kept in the system and can provide "services" to the life around it.

In a study led by Prof. Arnon Karniali, a remote sensing expert from Ben-Gurion University of the Negev, and in collaboration with the Kimat Israel Foundation, they examined how rain and runoff management affected the functional rehabilitation of remote areas in the Negev. As part of the research, they tested the effectiveness of limens - earthen dams originating from an ancient agricultural method that prevents the loss of runoff water that flows down the wadi. The limes create small lakes from rainwater and floods, within which water can seep into the ground and trees can grow. "There are more birds, you can put a hive of bees that will enjoy the nectar, there are more annual [shrubs] that grow under the trees," Karniali says.

Desert landscape in the Ein Gedi area. Photo: pexels, haleyve

Historically, most of the trees were uprooted by the Turks during the First World War. Photo: pexels, haleyve

Despite the claims that the levees stop the flow in the wadis, he points out that the levees do not harm the water balance downstream of the wadi. "On the contrary, you stop the floods in small basins and prevent water loss." The storage of the water in the lime trees, he explains, stops it from flowing until it reaches the sea without being put to beneficial use such as seeping and nourishing the soil. The liman is a kind sink which manages to gather in one place many materials important to the quality of the soil such as the increased presence of organic matter in the soil and of phosphorus that contributes toplant growth, in particular in areas of drought and extreme heat. According to an article published in the journal 'Ecology and environment', in arid and semi-arid areas where there is not enough organic matter, the soil structure is weakened. In this situation, when the runoff or rainwater meets the soil surface, it sweeps the soil particles away instead of percolating through them.

The area cells that were tested were those with trees that were planted in the 50s, "from the northern area [of KKL-Junk lands], south of Kiryat Gat, [where] the precipitation can reach 450 mm per year," says Siaki. "To the south, the Beer Sheva area, where the rains can reach an average of 200 mm per year." As part of the research, they used satellite images that detected changes in the surface between 1984-2020 and with the help of machine learning tools, they obtained a snapshot of the vegetation over the years. These tools make it possible to see the changes on a large scale and over many years, and help us to examine ourselves," says Siaki, adding that they examined Is KKL's rehabilitation activity beneficial, harmful or does it not change the environment in question. The research, as mentioned, found that lime trees provide an excellent solution for the successful growth of trees.

There used to be trees here

"Historically, most of the trees were uprooted by the Turks during World War I. The Turks needed a lot of flammable materials to power their trains and simply uprooted and used all the overgrown areas in the State of Israel," says Karniali. According to him, the restoration makes it possible to restore the landscape that characterized the area a long time ago. In view of KKL-Junk's many afforestation efforts, Israel is one of the only countries in the world that has more trees today than it did a century ago.

The use of runoff water to rehabilitate flooded areas also helps for aesthetic and recreational purposes; The sites where limans exist have become "resort spots" where people park in the shade of the trees. "From a scenic point of view, when you travel and you have trees in a desert environment, and you see the development of a green landscape instead of yellow or gray - it's more pleasant for you to travel," says Karniali.

Afforestation and restoration in a desert area, according to Siaki, are long processes. "It's not something you can see a year after planting, nor five years after." The new tools used in the research proved to be effective. "The model can be used by us in other, more northern regions, when the desert rises." In fact, it is also relevant outside the borders of Israel. "In the world, in climatic areas similar to ours, he can contribute," he concludes.

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