The incident of Chernobyl Nuclear Power Plant (CNPP) explosion has pioneered a plethora of studies unfolding various biological effects of radiation stress on several living systems. Determining radiation dose rates at which both acute and chronic biological effects occur in different biological systems will aid in the ex-situ generation of radiation-tolerant organisms. So far, the accumulation of data on different radiation doses from Chernobyl area demonstrating various biological impacts has not been documented altogether vastly. Therefore, this review aims to document the recorded doses in CNPP over the years at which different biological changes have been observed in plants, soil, aquatic organisms, birds, and animals. A total of 72 peer-reviewed papers obtained from PubMed, Google Scholar, Scopus, and Research4life were included in this review. A few factors have come under attention in this review. Firstly, plant and soil systems combinedly showed the most published studies after the catastrophe where plants showed a higher frequency of DNA methylation in their genome to resist radiation stress. Secondly, reduced species abundance, chromosomal aberrations, increased sterility, and mortality were mostly observed in the aftermath of Chernobyl catastrophe among plants, soil, aquatic organisms, birds, and small mammals. Furthermore, major scares of data after 2018 were prominently observed. Very few studies on radiation dose levels after 2018 are available. Hence, a major research area has emerged for radiation biologists to study present radiation levels and any genetic changes in the recent generation of the original victim species. This will help provide a standard dataset that can act as a reference resource for radiation biologists and future research on the impact of both acute and chronic radiation on the different biological systems. [GRAPHICS] .

Background Alpine ecosystem underlain by permafrost is considered as one of the most vulnerable ecosystems to disturbance, especially the alpine grassland on the Tibetan plateau with an altitude above 4000 m. Plateau pika (Ochotona curzoniae) burrowing can create distinctive bare grounds and cause micro-topographical heterogeneity in alpine grasslands. The burrowing-induced changes in microtopography may directly alter plant and soil interactions as well as ecosystem carbon cycle, which have rarely been studied in Tibetan alpine grasslands. Methods To test the responses of ecosystem respiration (Re) to pika burrowing-induced changes in microtopography, we investigated plant characteristics, soil properties and Re from the bare grounds and vegetated grounds in the alpine meadow and steppe on the Tibetan Plateau. Results Our study showed that vegetation cover, species richness, plant biomass, soil moisture (SM), soil organic carbon (SOC), total nitrogen (STN), soil microbial biomass carbon (MBC) and nitrogen (MBN) in the bare grounds were significantly lower than in the vegetated grounds in both alpine meadow and alpine steppe (P < 0.05). However, soil temperature and inorganic nitrogen tended to increase in the bare grounds. The growing season Re was significantly lower in the bare grounds than that in the vegetated grounds (P < 0.01). Pika burrowing had negative effects on Re and its temperature sensitivity in both alpine vegetations (P < 0.05). The relative changes in Re due to burrowing-induced changes in microtopography were positively correlated with the burrowing caused changes of AGB, BGB, SOC and MBC (P < 0.05). Pika burrowing-induced changes in soil temperature, soil moisture, plant biomass and microbial biomass are the major factors for the decrease of Re in the bare grounds. Conclusion In view of the large number of pika burrows in the alpine grasslands and the loss of soil organic carbon due to pika bioturbation, the impacts of pika burrowing-induced changes in microtopography on Re must be considered in predicting the carbon cycle in alpine grasslands.