Browsing by Author "Bibi, Farkhanda"

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    Leaf Functional Traits of Invasive Grasses Conferring High-Cadmium Adaptation Over Natives
    (Daffodil International University, 2022-06-20) Ilyas, Muhammad; Shah, Sakhawat; Lai, Ya-Wen; Sher, Jan; Bai, Tao; Zaman, Fawad; Bibi, Farkhanda; Koul, Monika; Wani, Shabir Hussain; Majrashi, Ali; Alharby, Hesham F.; Hakeem, Khalid Rehman; Wang, Yong-Jian; Rather, Shabir A.
    Heavy metal (HM) contamination resulting from industrialization and urbanization during the Anthropocene along with plant invasion can severely threaten the growth and adaptation of local flora. Invasive alien plant species generally exhibit a growth pattern consistent with their functional traits in non-contaminated environments in the introduced range. However, it remains unclear whether invasive alien plants have an advantage over native plants in contaminated environments and whether this growth pattern is dependent on the adaptation of their leaf functional traits. Here, we selected two congeneric pairs of invasive alien and native grasses that naturally co-exist in China and are commonly found growing in contaminated soil. To evaluate the effect of cadmium (Cd) on the structural and physiological leaf traits, we grew all four species in soil contaminated without or with 80 mg/kg Cd. Invasive plants contained significantly higher concentrations of Cd in all three organs (leaf, stem, and root). They displayed a higher transfer factor and bioconcentration factor (BCF) of shoot and root than natives, indicating that invasive species are potential Cd hyperaccumulators. Invasive plants accumulated polyphenol oxidase (PPO) to higher levels than natives and showed similar patterns of leaf structural and physiological traits in response to changes in Cd bioconcentration. The quantifiable leaf structural traits of invasive plants were significantly greater (except for stomatal density and number of dead leaves) than native plants. Leaf physiological traits, chlorophyll content, and flavonoid content were also significantly higher in invasive plants than in natives under Cd stress conditions after 4 weeks, although nitrogen balance index (NBI) showed no significant difference between the two species. Chlorophyll fluorescence parameters decreased, except for the quantum yield of photosystem II (ΦPSII) and the proportion of open photosystem II (qP), which increased under Cd stress conditions in both species. However, invasive plants exhibited higher fluorescence parameters than natives under Cd stress, and the decrement observed in invasive plants under Cd stress was greater than that in natives. High Cd adaptation of invasive grasses over natives suggests that invasive plants possess optimal leaf structural and physiological traits, which enable them to adapt to stressful conditions and capture resources more quickly than natives. This study further emphasizes the potential invasion of alien plants in contaminated soil environments within the introduced range. To a certain extent, some non-invasive alien plants might adapt to metalliferous environments and serve as hyperaccumulator candidates in phytoremediation projects in contaminated environments.
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    Seasonal Variations of Fine Root Dynamics in Rubber-Flemingia Macrophylla Intercropping System in Southwestern China
    (Scopus, 22-10-12) Bibi, Farkhanda; Balasubramanian, Durairaj; Ilyas, Muhammad; Sher, Jan; Hamz Ali, Samoon; Hayder Bin Khalid, Muhammad; Alharby, Hesham F.; Majrashi, Ali; Alghamdi, Sameera A.; Hakeem, Khalid Rehman; Shah, Muddaser
    Intercropping cover crops with trees enhance land productivity and improves the soil’s physio-chemical properties while reducing the negative environmental impact. However, there is a lack of quantitative information on the relationships between fine root biomass and available soil nutrients, e.g., nitrogen (N), phosphorus (P), and potassium (K), especially in the rubber-Flemingia macrophylla intercropping system. Therefore, this study was initiated to explore the seasonal variation in fine root biomass and available soil nutrients at different stand ages (12, 15, and 24 years) and management systems, i.e., rubber monoculture (mono) and rubber-Flemingia macrophylla intercrop- ping. In this study, we sampled 900 soil cores over five seasonal intervals, representing one year of biomass. The results showed that the total fine root biomass was greater in 12-year-old rubber monoculture; the same trend was observed in soil nutrients P and K. Furthermore, total fine root biomass had a significant positive correlation with available N (p < 0.001) in rubber monoculture and intercropping systems. Thus, it suggests that fine root growth and accumulation is a function of available soil nutrients. Our results indicate that fine root biomass and soil nutrients (P and K) may be determined by the functional characteristics of dominant tree species rather than collective mixed-species intercropping and are closely linked to forest stand type, topographic and edaphic factors. However, further investigations are needed to understand interspecific and complementary interactions between intercrop species under the rubber-Flemingia macrophylla intercropping system.