Background and Aims Human activities-mediated input of nitrogen (N) and phosphorus (P) to ecosystem may significantly affect soil hydrolyzing enzyme activities (Hy-EAs). However, the mechanisms underlying the responses of soil Hy-EAs to change in N and P availability remains unclear. Methods Here, a two-year field N and P addition experiment was conducted in a subtropical evergreen broad-leaved forest to elucidate the effects of N addition, P addition, and NP co-additions on soil Hy-EAs and biochemistry properties. Results The invertase, cellulase, and acid phosphatase activities were increased in N treatment but reduced in P treatment. The urease activity was reduced in N treatment but did not alter in P treatment. NP treatment significantly increased the invertase and cellulase activities. Furthermore, the cellulase activity was positively correlated with soil organic carbon concentration. The acid phosphatase activity was negatively correlated with microbial biomass carbon (MBC), total P, and available P concentrations. Whereas the urease activity was not strongly dependent on total N concentrations, but positively correlated with soil pH and MBC. These Hy-EAs were significantly correlated with C-to-P and N-to-P ratios, while no significantly correlation with C-to-N ratio. Conclusions Overall, our results indicated that N and P addition significantly affected the soil C-, N-, and P-hydrolyzing enzyme activities. With ongoing imbalanced N and P input in our studied subtropical evergreen broad-leaved forest, N addition may exacerbate the limitation of soil C and P availability, while the exogenous P addition may improve the soil C and P availability.

The red imported fire ant (RIFA) is one of the most detrimental invasive species, threatening native ecosystems, human health, and economic activities worldwide. In the quarantine zone of Taiwan, RIFA re-infestation frequently occurs despite the intensive application of synthetic pesticides, making its control costly and ineffective. Thus, there is an urgent need to identify effective, eco-friendly, and sustainable alternatives for controlling RIFA populations. In this study, we examined the efficacy and feasibility of planting herbal species for RIFA control. Five herbal species, Tagetes lemmonii, Armoracia rusticana, Cymbopogon citratus, Cymbopogon nardus, and Chrysopogon zizanioides, were planted in a RIFA-infested field with local weeds as controls. Bait and pitfall traps and RIFA intruded plants were used to compare the ant activity in the control fields and those containing herbal plants. The RIFA repellent activity of the five herbal plants and their basal soil was further evaluated through digging bioassays. Generally, the field surveys showed more ants and intruded plants in the control than in the herbal groups; however, the significance varied based on the trap type and plant species. The bioassays demonstrated the significant repellency of the aboveground parts of T. lemmonii, C. nardus, and C. citratus, and the belowground parts of T. lemmonii, C. citratus, and V. zizanioides against RIFA. The basal soil of T. lemmonii, C. citratus, and C. nardus also exhibited deterrent activity toward RIFA. Our results demonstrated that herbal plants are eco-friendly, sustainable alternatives for controlling and preventing RIFA infestation in severe infested and non-infested areas.

Aiming to develop a sociocultural understanding of learner agency as defined by Ahearn (2001), this study asks the questions: How do English majors under the Program for Interdisciplinary English Talents in Chinese universities with international or regional orientations experience their English learning and exert learner agency differently? Which factors influence learners’ agentive activities and what differences exist in the influencing strength of those factors? Interview data were collected from 14 student participants from two representative universities in the eastern part of China. Analyzing the data using the framework proposed by Dang and Marginson (2013) revealed that learners’ agentive activities are mediated by the sociocultural context, in which the global, national and local factors exert great influences and their influencing strength varies. Among all the factors, the influence of the microgenetic domain, to be specific, the institutional context is the greatest. Implications and suggestions are provided based on the results.