The use of UAV-based remote sensing to estimate biomass and carbon stock for native desert shrubs.

Unmanned Aerial Vehicles (UAVs) have started to receive more attention in the ecological field in the past 15 years, as they provide very high-resolution imagery that ranges from meters to millimeters. Very high-resolution multispectral imagery obtained from UAVs can help in assessing and monitoring native desert vegetation. Thus, this study use UAVs to develop a method to estimate the biomass and carbon stock of native desert shrubs. The method integrates different techniques and software to monitor native plants' coverage, biomass, and carbon stock. The techniques used in this work are also applicable for other native desert shrubs in the region and could support ecosystem managers in assessing and monitoring arid ecosystems and restoration and revegetation programs. A three-stage image and data management are discussed, including: (1) fieldwork and image acquisition using UAVs, (2) image pre-processing, and (3) image processing using different techniques and software.•Determining shrub biomass is not restricted to multispectral data only but could be applicable for RGB data since it mainly depends on the DSM and DTM.•Allometric parameters could help in estimating desert shrub biomass which could be measured easily and rapidly using UAV imagery.•SVM Supervised classification could help in distinguishing between native shrubs and grasses.

The Use of Very-High-Resolution Aerial Imagery to Estimate the Structure and Distribution of the Rhanterium epapposum Community for Long-Term Monitoring in Desert Ecosystems.

The rapid assessment and monitoring of native desert plants are essential in restoration and revegetation projects to track the changes in vegetation patterns in terms of vegetation coverage and structure. This work investigated advanced vegetation monitoring methods utilizing UAVs and remote sensing techniques at the Al Abdali protected site in Kuwait. The study examined the effectiveness of using UAV techniques to assess the structure of desert plants. We specifically examined the use of very-high-resolution aerial imagery to estimate the vegetation structure of Rhanterium epapposum (perennial desert shrub), assess the vegetation cover density changes in desert plants after rainfall events, and investigate the relationship between the distribution of perennial shrub structure and vegetation cover density of annual plants. The images were classified using supervised classification techniques (the SVM method) to assess the changes in desert plants after extreme rainfall events. A digital terrain model (DTM) and a digital surface model (DSM) were also generated to estimate the maximum shrub heights. The classified imagery results show that a significant increase in vegetation coverage occurred in the annual plants after rainfall events. The results also show a reasonable correlation between the shrub heights estimated using UAVs and the ground-truth measurements (R2 = 0.66, p < 0.01). The shrub heights were higher in the high-cover-density plots, with coverage >30% and an average height of 77 cm. However, in the medium-cover-density (MD) plots, the coverage was <30%, and the average height was 52 cm. Our study suggests that utilizing UAVs can provide several advantages to critically support future ecological studies and revegetation and restoration programs in desert ecosystems.

Investigating the applicability of UAVs in characterizing desert shrub biomass and developing biological indicators for the selection of suitable revegetation sites.

This study focused on evaluating factors influencing the growth of perennial shrubs by integrating field-based experiments and spatial analysis using unmanned aerial vehicles (UAVs) to identify ecological indicators that can help detect potential locations for restoration and revegetation of native plants. The experiment was implemented in the Al-Abduli protected area in Kuwait, which is mainly dominated by a Rhanterium epapposum community (desert shrub). Aerial imagery of the study site was acquired using UAVs during the growing season to estimate the desert shrub biomass and carbon stock. Then, soil samples were collected based on vegetation density to determine the impact of the soil's physical and chemical properties on vegetation biomass, growth, and distribution. It was found that shrub biomass was significantly correlated with crown area and shrub volume. We also observed that annual plants support the growth of perennial shrubs, as the mean shrub height and crown area (CA) are significantly higher, with averages of 0.7 m and 3 cm, respectively, in the presence of high annual plant density. However, shrubs in plots with low annual density had an average shrub height of 0.5 m and CA of 1.4 cm. Annual plants also enhance the soil by providing approximately 50% higher soil moisture, phosphorous (P), organic matter (OM), and carbon dioxide (CO2) sequestration. In addition, annual plants are mainly supported by loamy soils in the deeper soil layers. We concluded that locations covered with annual plants represent suitable soils and that this can be considered a biological indicator for convenient locations for restoration and revegetation of native perennial shrubs. Remote sensing technologies could be utilized for initial assessments to detect sites that may support annual plant growth over a large scale for classification as potential restoration and revegetation areas.

The immediate impact of the associated COVID-19's lockdown campaign on the native vegetation recovery of Wadi Al Batin Tri-state desert.

Law enforcement and massive media awareness, limiting the anthropogenic disturbance, is the way to go for implementing successful desert native vegetation recovery plans. A lesson learned on the resiliency of desert ecosystems throughout studying the native vegetation coverage in the Wadi Al-Batin desert ecosystem during the COVID-19 pandemic. Wadi Al-Batin tri-state desert (89,315 km2) covers the South-western part of Iraq, State of Kuwait, and the North-eastern part of Saudi Arabia. In this study, the spatiotemporal changes in vegetation coverage was detected, by using Sentinel-2A imageries, during the period from 2017 to 2020. For better understanding the impact of associated law enforcement and media practices during COVID-19 pandemic, native vegetation coverage of years with relevant rainfall records were compared. The results revealed that despite receiving the least amount of rain of the three years (≤93 mm), the COVID-19 year (2020) had the highest native vegetation coverage at 28.5% compared with 6% in 2017, and 2% in 2018. These results prove that the main drivers of desert vegetation deterioration are anthropogenic activities, such as quarrying, overgrazing, distractive camping, and off-road vehicle movements. Moreover, the estimated 63% vegetation coverage in Wadi Al-Batin desert in 2019 assures the significant role of precipitation in desert vegetation recovery. This bulk increase in vegetation coverage detected during COVID-19 pandemic shows that the desert vegetation adapts to harsh environments (low rainfall) and rapidly recovers once the source of the disturbance was removed by enforcing the environmental rules. Thus, the protection of natural resources and ecosystems can be achieved through the synergy between governments and civil communities, including intensive awareness of environmental impacts via media, enforcing environmental regulations, and promoting regional collaboration.