Search

Mining can significantly alter landscapes, impacting wildlife and ecosystem functionality. Natural recovery in open‐pit mines is vital for habitat restoration and ecosystem re‐establishment, although few empirical studies have examined this process. Here, we assessed temporal and spatial responses of small rodents at the community, population, and individual levels during natural mine recovery. We examined the abundance, reproductive potential, and individual health of small rodents at active mines and at former mine sites left to recover naturally for approx. 10 and 20 years. We also assessed the effects of disturbance on rodent recovery processes at three distances from the mine boundary. Rodent numbers peaked after 10–13 years of recovery and exhibited the strongest male bias in the sex ratio. The Chinese white‐bellied rat (Niviventer confucianus) was the most abundant species, achieving its highest population abundance at sites abandoned for 10–13 years and thriving at locations closer to the mine boundary. Only Chevrier's field mouse exhibited morphological responses to the mine recovery category. Ectoparasite load was unaffected by mine or distance‐disturbance categories. Both Chevrier's field mouse (Apodemus chevrieri) and the South China field mouse (Apodemus draco) were affected significantly by vegetation layer cover during recovery succession. Our study highlights the complexities of ecological succession, with a peak in abundance as pioneer communities transition toward a climax seral stage. Careful prior planning and active site management are necessary to optimize abandoned mine recovery. Efforts to accelerate mine recovery through technical restoration should promote conditions that initiate and perpetuate the establishment and succession of wildlife assemblages. [ABSTRACT FROM AUTHOR]

As one of the leading technologies for chemical enhanced oil recovery (cEOR), surfactant–polymer (SP) flooding technology has long attracted the interest of petroleum scientists and engineers. However, most of its application scenarios are based on the five-spot well pattern. The EOR potential in an inverted seven-spot well pattern is seldom ever recorded. The applicability of the SP system in the inverted seven-spot well pattern was examined based on the physical characteristics of Karamay Oilfield in China. The numerical simulation and the one-dimensional core flooding experiment were used to compare the sweep intensities and EOR abilities of the two well patterns. The migration law and the EOR ability of the SP system were assessed by a specially made one-third inverted seven-spot configuration. The main controlling factors and compatibility charts of SP flooding development in the inverted seven-spot well pattern were obtained. Results show that 61% of the region is represented by a weak swept state in the inverted seven-spot well pattern. The effective swept area is greatly increased by appropriately raising the viscosity and slug size of the SP system. Compared to constant viscosity injection, step-down viscosity injection further increases the sweep range and oil recovery. The inverted seven-spot well pattern has a greater swept area of the SP system than the five-spot one, but a weaker strength. Polymer concentration is the most effective factor of SP flooding in the inverted seven-spot well pattern, followed by oil viscosity and surfactant concentration. The study can broaden the application of the SP system in the inverted seven-spot well pattern. [ABSTRACT FROM AUTHOR]