Pioneer Species Selection for Post-Mining Rehabilitation of Stone Mining Sites in the Central Aravalli Region

Available online www.ejaet.com European Journal of Advances in Engineering and Technology, 2017, 4(12):926-928 Research Article ISSN: 2394 - 658X 926 Pioneer Species Selection for Post-Mining Rehabilitation of Stone Mining Sites in the Central Aravalli Region Veenu Agarwal Department of Botany, SGSG Government College, Nasirabad, Ajmer, India veenu[email protected]m _____________________________________________________________________________________________ ABSTRACT This study investigates the selection and effectiveness of pioneer species for the post-mining rehabilitation of stone mining sites in the Central Aravalli region. Stone mining activities in the Aravalli hill lead to significant environmental degradation, including soil erosion, loss of biodiversity, and disruption of ecosystems. This paper identifies a range of indigenous pioneer species that can be employed in reclamation projects, focusing on their ecological suitability, growth rates, and ability to stabilise soil and improve soil quality. Field trials and litera-ture reviews provide insights into best practices for rehabilitation efforts in this ecologically sensitive region. Keywords: Central Aravalli region, Stone Mining Sites, rehabilitation sites, ecological processes _____________________________________________________________________________________________ INTRODUCTION The Aravalli Range, one of the oldest mountain ranges in India, has been extensively mined for stone and minerals, leading to significant ecological degradation. Stone mining activities disrupt local ecosystems, result in soil erosion, and pose challenges to biodiversity conservation. Rehabilitating these areas requires an understanding of the ecological processes that govern land recovery and the role of pioneer species in restoring vegetation cover. This paper aims to explore the role of pioneer species in the rehabilitation of post-mining stone sites in the Central Aravalli. Pioneer species, which are the first plants to colonise disturbed lands, play a crucial role in soil stabilisation, nitrogen fixation, and facilitating the establishment of other plant species, thereby aiding ecological succession. The process of ecological succession in post-mining landscapes is critical for the recovery of biodiversity and soil stability. Pioneer species, due to their ability to colonise degraded lands, are fundamental to initiating restoration processes. The concept of ecological succession and the role of pioneer species in post-mining environments has been well documented in ecological research. Key studies highlight the importance of selecting plant species that can tolerate extreme conditions, improve soil quality, and foster biodiversity recovery. Bradshaw [1] emphasised the necessity of using natural ecological processes for the rehabilitation of mined lands. He advocated for the selection of plant species that are not only hardy but also ecologically suited to the harsh conditions of degraded sites. Parrotta et al. [2] demonstrated in their study on bauxite-mined areas in Amazonia that fast-growing, native pioneer species significantly enhance the development of floristic diversity. Their work supports the strategy of introducing such species in early stages of rehabilitation to accelerate ecosystem recovery. Singh and Singh [3] investigated bamboo plantations in dry tropical regions and found that these species contributed substantially to biomass production and soil redevelopment, reinforcing the idea that native plants can drive long-term ecological benefits in post-mining recovery. Numerous studies emphasise the importance of pioneer species in soil erosion control, such as grasses, legumes, and fast-growing shrubs, which help to stabilise the soil and prevent further degradation [4]. These species are typically drought-tolerant and capable of surviving in nutrient-poor soils. Similarly, Ghose [5] highlighted the role of topsoil preservation in the geo-environmental reclamation of coal mining areas, stressing that early interventions, including the introduction of stabilising vegetation, are essential for successful restoration. Lugo [6] noted that even monoculture plantations, often used for their quick establishment, can create microhabitats conducive to the colonisation of other plant and animal species, thereby indirectly promoting biodiversity recovery. The Central Aravallis, a biodiversity hotspot, have been subjected to a variety of mining activities, with various studies focusing on rehabilitative efforts. However, limited research specifically addresses the selection of Agarwal V Euro. J. Adv. Engg. Tech., 2017, 4(12):926-928 927 appropriate pioneer species in these arid and semi-arid conditions a localised perspective was provided by Yadav and Yadav [7], who documented the success of native pioneer species in the rehabilitation of abandoned mining sites in the Aravalli Hills. Their findings confirm the relevance of indigenous plants in region-specific restoration efforts. STUDY AREA The study was conducted across various stone mining sites in the Central Aravalli region of Rajasthan. These areas were selected based on their environmental degradation caused by extensive mining activities. The region's harsh climatic conditions, including low rainfall and high temperatures, present unique challenges for ecological restoration. Geographically, the Central Aravallis are characterised by rugged terrain, poor soil quality, and disturbed ecosystems, making them a critical area for ecological restoration research. MATERIALS AND METHODS Site Selection A total of 10 mining sites were selected within the Central Aravallis, based on their level of degradation, distance from natural ecosystems, and accessibility for rehabilitation studies. Pioneer Species Selection Criteria The species were selected based on the following criteria: • Ecological Adaptability: Tolerance to drought, soil salinity, and high temperature. • Soil Improvement: Ability to fix nitrogen or contribute organic matter to the soil. • Growth Rate: Fast-growing species that can establish a quick cover to prevent further erosion. • Native Species: Preference for indigenous species to ensure the restoration of local biodiversity. Pioneer Species Selected The following species were chosen based on preliminary studies and ecological suitability: • Acacia nilotica (Indian gum acacia) • Leucaena leucocephala (Subabul) • Cassia tora (Coffee Senna) • Cenchrus ciliaris (Buffel grass) • Tephrosia villosa (Wild indigo) Field Trials The rehabilitation efforts included: • Soil Analysis: Preand post-rehabilitation soil samples were collected for analysis of organic carbon, nitrogen content, pH, and texture. • Plant Growth Monitoring: Growth rates of selected pioneer species were monitored over a period of 12 months, with measurements of height, biomass, and root development. • Vegetation Cover: Visual assessments of vegetation cover and species composition were conducted. Data Analysis Statistical analysis was performed using software like SPSS and R to evaluate the growth success and soil improvement associated with each species. ANOVA and regression models were used to determine the relationship between plant growth and soil conditions. RESULTS The rehabilitation sites demonstrated significant ecological improvements across various parameters, depending on the species introduced. Species Nitrogen Content (% Increase) Organic Carbon (% Increase) pH Change (Δ) Leucaena leucocephala +45% +35% +0.3 Acacia nilotica +38% +28% +0.2 Cassia tora +12% +14% +0.1 Cenchrus ciliaris +9% +11% - Soil samples (n = 50) were tested before and after a 12-month period using Kjeldahl digestion for nitrogen and Walkley-Black method for organic carbon. Improvements were most significant in Leucaena and Acacia plots (p < 0.01, ANOVA). Species Mean Height (cm) Biomass (kg/m²) Vegetation Cover (%) Cenchrus ciliaris 85 2.1 70 Cassia tora 90 1.8 65 Tephrosia villosa 72 1.5 55 Leucaena leucocephala 160 3.3 45 Agarwal V Euro. J. Adv. Engg. Tech., 2017, 4(12):926-928 928 The rehabilitation sites exhibited varying success based on the species planted: Soil Quality Improvement: Sites where Leucaena leucocephalawas planted showed significant improvements in nitrogen content and soil organic matter. Acacia nilotica also contributed to increased soil fertility through nitrogen fixation. Plant Growth and Coverage: Cassia tora and Cenchrus ciliaris exhibited the fastest growth rates, covering large areas quickly. However, they were less effective in soil fertility improvement compared to Leucaena and Acacia. Biodiversity Recovery: Rapid canopy cover was noted in Cenchrus and Cassia, while Leucaena demonstrated superior biomass accumulation and nitrogen contribution. Within 12 months, secondary colonisation was observed with 14 new herbaceous species and 3 shrub species in Leucaena and Acacia plots—an increase of 40% in plant diversity. Over time, the establishment of pioneer species created microhabitats, enabling the colonisation of secondary species. DISCUSSION The success of pioneer species in post-mining rehabilitation depends on their ability to adapt to harsh conditions and their interaction with the soil environment. The high growth rates of species like Cenchrus ciliaris helped rapidly cover the bare soil and reduce erosion. Its lower contribution to soil organic matter underscores the need for a mixed-species strategy while Leucaena leucocephala significantly improved soil quality, supporting the establishment of secondary species. The findings suggest that a combination of fast-growing grasses and nitrogenfixing shrubs is optimal for rehabilitating post-mining sites in the Central Aravallis. The challenge remains in scaling these efforts across large mining sites and ensuring long-term sustainability. CONCLUSION The selection of appropriate pioneer species is critical for successful post-mining rehabilitation, especially in the challenging conditions of the Central Aravallis. This study has demonstrated that species like Leucaena. leucocephala and Acacia nilotica can play a significant role in soil restoration, while grasses like Cenchrus ciliaris are essential for quick cover. Further studies should focus on long-term monitoring of these rehabilitation efforts and explore the potential for introducing additional species for greater biodiversity recovery. REFERENCES [1]. AD Bradshaw, Restoration of mined lands—using natural processes. Ecological Engineering, 1997, 8(4), 255–269. [2]. JA Parrotta, OH Knowles and JM Wunderle, Development of floristic diversity in 10-year-old restoration forests on a bauxite-mined site in Amazonia, Forest Ecology and Management, 1997, 99(1-2), 21–42. [3]. AN Singh and JS Singh, Biomass, net primary production and impact of bamboo plantation on soil redevelopment in a dry tropical region, Forest Ecology and Management, 2006, 233(1), 287–295. [4]. P Ghosh and S Choudhury, Ecological restoration of mined lands: A review. Environmental Management, 2014, 55(2), 123-138. [5]. MK Ghose, Management of topsoil for geo-environmental reclamation of coal mining areas. *Environmental Geology, 2001, 40(11-12), 1405–1410. [6]. AE Lugo, The apparent paradox of reestablishing species richness on degraded lands with tree monocultures, Forest Ecology and Management, 1997, 99(1-2), 9–19. [7]. BP Yadav and S Yadav, Reclamation and Rehabilitation of Abandoned Mined Lands in Aravallis: A Case Study, Indian Journal of Environmental Protection, 2011, 31(12), 1011–1016.