Estimation and Comparison of Natural Ranges and Abandoned Rangelands Using Remote Sensing-Based Vegetation Indices: A Case Study of Chaharmahal and Bakhtiari Province Rangelands

The cultivation and subsequent abandonment of rangelands due to economic non-viability have become prevalent in recent years. Assessing plant productivity in these abandoned rangelands is essential for their restoration. This study aims to compare the effectiveness of vegetation indices in natural and abandoned rangelands, evaluate variations in plant productivity, and provide insights into their ecological conditions.

Three semi-steppe regions in Chaharmahal and Bakhtiari province were selected as study areas. These regions were previously degraded for agriculture and subsequently abandoned. Field sampling and satellite data were used to assess plant productivity. Plant indices, including NRVI, CTVI, RATIO, TTVI, and TVI, were calculated using Landsat 8 satellite images from 1393. The indices were employed to evaluate plant productivity and compare natural and abandoned rangelands.

NRVI, CTVI, RATIO, TTVI, and TVI exhibited a significant correlation with plant productivity, while other indices did not accurately represent it. The NRVI index provided the most accurate estimation of plant productivity in abandoned and cultivated rangelands. Uncultivated rangelands showed higher productivity compared to cultivated ones. The study areas displayed variations in plant productivity, with Marjen Borujen having the highest productivity in uncultivated sections and Sefid Dasht having the lowest. In the cultivated sections, Sefid Dasht had the lowest productivity, while Hoorah had the highest. Shrubs experienced the most substantial reduction in plant productivity among the vegetation forms.

Remote sensing, particularly the NRVI index, proved valuable for assessing plant productivity in these rangelands. Utilizing the NRVI index can aid in the management and restoration of abandoned and cultivated rangelands. Conducting similar research and employing remote sensing techniques for assessing and monitoring various rangeland areas are crucial for sustainable land management and conservation efforts. These approaches contribute to the overall health and sustainability of these valuable ecosystems.