Keywords

1 Introduction

Aeolian processes are activated by predominant high wind speed, scanty vegetation, long drought periods, light-textured topsoil and low topographic relief (Al-Awadhi and Al-Dousari 2013). The mobile sand and dust particles movement cause sand encroachment in human settlements and poses serious economic and environmental threats (Ahmed et al. 2015). Native plants were found to have operative control measures for mobile sand in Iraq (Fadhil 2002); Saudi Arabia (Alghamdi and Al-Kahtani 2005); Iran (Pahlavanravi et al. 2012); and South Korea (Hong and Lee 2016). The native plants were found to be effective in controlling aeolian activities, soil sealing (Al-Dousari et al. 2000), wind’s erosive force and act as soil organic carbon storage (Burri 2011). Native plants are proficient in catching mobile aeolian sediments forming aeolian landform called nabkha (Al-Dousari and Pye 2005). Nabkha is an aeolian accumulation around a native plant (Cooke et al. 1993; Khalaf et al. 1995; Al-Dousari et al. 2008; Ahmed et al. 2015). The nabkha formation around native plants is economically and environmentally significant as it controls mobile sand and suspended dust particles in desert and semi-desert regions (Darwish et al. 2013; Ahmed et al. 2015) and reduce sand encroachment problem. Therefore, the aim of this study was to identify the characteristics of sediments that form around dominant plants in Kuwait and detect their efficiency in controlling aeolian activities.

2 Materials and Methods

In order to test the effectiveness of each native plant species in capturing mobile sand and dust, the morphological dimensions (length, height and width) were measured through intensive field survey in 47 site locations in Kuwait (Fig. 1a, b). These native plants are Calligonum polygonoides, Cyperus conglomeratus, Haloxylon salicornicum, Rhanteium epapposum, Astragalus spinosus, Lycium shawii, Citrullus colocynthis, Panicum turgidum, Salicornia europaea, Heliotropium bacciferum, Arnebia decumbens, Nitraria retusa, Tamarix aucheriana, Convolvulus oxyphyllus and Halocnemum strobilaceum. The largest nabkhas around each plant species were visually selected and measured within the 47 sites (Fig. 1c, d). In this study, the largest 20 nabkhas for each of the 15 plant species were considered for morphological dimensions and soil analysis (Alkalinity, conductivity level, moisture and particle size as well as carbonate percentages). The nabkha volume was then calculated via our formula as follows:

Fig. 1
figure 1

Sampling location map (a), nabkha dimensions sketch (b), and field photos for nabkha of two different native plants (c, d)

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$$ {\text{The total nabkha volume }} = V_{E} + V_{P} = \frac{{\pi .a_{1} .b_{1} .c_{1} }}{12} + \frac{{\alpha .d^{5} .\tan \theta }}{5} $$

where a1 is height from ground level and equal to vertical radii, b1 is total width, and c1 is horizontal radius. The tailing volume is calculated by integrating the base from zero to vertical radius (a) \( V_{P} = \int A .da_{1} \). The area of the surface = b1.d, where b1 = d. tan θ.

3 Results and Discussion

The native plants, mainly Nitraria, Lycium, Haloxylon, and Calligonum formed the maximum volumes of nabkha deposits up to 21.9, 15.5, 14.5 and 13.3 m3, respectively. Therefore, these plants are the most effective solutions as aeolian processes future control measures. The effectiveness of these native plants in controlling aeolian processes can be due to the morphometric parameters of these plants compared to others. This was noted by Al-Dousari et al. (2008), Ahmed et al. (2015), and El-Wahab (2018). Native plants are a workable solution to control aeolian activities in Kuwait and the surrounding areas (Al-Dousari and Al-Awadhi 2012 and Al-Dousari et al. 2017). They only require 2–3 years of irrigations; then, they adapt to weather conditions (112 mm mean annual rainfall). On the other hand, aeolian sand and dust are part of the desert ecological system and they act as a healing factor for degraded lands as a constant supplier of plants seeds. Dust and mobile sand contain organic matter up to 8.96 and 4.85%, respectively from total sample weight (Al-Dousari et al. 2016). The proper use of native plants in controlling aeolian mobile sand was successful in Syria (Al-Obaid 2000), Saudi Arabia (Alghamdi and Al-Kahtani 2005), Iran (Pahlavanravi et al. 2012), Chad (Djibril 2013), Egypt (Darwish et al. 2013), Morocco (Hammouzaki 2013) and China (Hong and Lee 2016).

The Astragalus sp. nabkhas mean grain size are considered to be the finest and high in carbonates as it grows in playa and alluvial fan deposits. Citrulus sp. nabkhas are characterized by the lowest pH, EC, and moisture content but the highest content of carbonate in comparison to other native plants. Lycium sp. has the longest distance between branches and to the equivalent nearby species. Cyperus conglomeratus, Haloxylon salicornicum and Rhanterium epapposum nabkha is characterized by more alkaline (pH) values, low moisture content and electrical conductivity (EC). The latter plants develop short branches spacing and at close distances with nearby nabkhas (Fig. 2).

Fig. 2
figure 2

The volume of aeolian accumulation around dominant native plants in Kuwait (the bars represent the maximum values)

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4 Conclusion

The average aeolian accumulation around native plants in Kuwait is equivalent to 1.92 m3. Some native plants show the best capability in controlling aeolian sediments. The maximum volumes of aeolian accretion were noted to be around Nitraria retusa (21.9 m3), Lycium shawii (15.5 m3), and Haloxylon salicornium (14.5 m3). It is noteworthy to consider them as the most efficient plants in controlling aeolian sediments in the region. Correspondingly, each native plant has its distinctive morphological and soil characteristics. The native plants were found to be the practical solutions in controlling aeolian accumulations and as they have a remarkable low cost. Therefore, they are recommended as potential future applications to control sand encroachment and resuspended dust particles in the region.