The short-term effects of two levels of air temperature (ambient and warmed) and light (full light and ca. 10% of full light regimes) on the early growth and physiology of Picea asperata and Abies faxoniana seedlings was determined using open-top chambers (OTC). The OTC manipulation increased mean air temperature and soil surface temperature by 0.51°C and 0.34°C under the 60-year plantation, and 0.69°C and 0.41°C under the forest opening, respectively. Warming, with either full-light or low-light conditions, generally caused a significant increase in plant growth, biomass accumulation, and stimulated photosynthetic performance of P. asperata seedlings. However, the warming of A. faxoniana seedlings only significantly increased their growth under low-light conditions, possibly as a result of photoinhibition caused by full light, which may shield and/or impair the effects of warming manipulation, per se, on the growth and physiological performance of A. faxoniana seedlings. In response to warming, P. asperata seedlings allocated relatively more biomass to roots and A. faxoniana more to foliage under similar environments. This might provide A. faxoniana with an adaptive advantage when soil moisture was not limiting and an advantage to P. asperata if substantial moisture stress occurred. Warming markedly increased the efficiency of PSII in terms of the increase in F v /F m and photosynthetic pigment concentrations for the two conifer seedlings, but the effects of warming were generally more pronounced under low-light conditions than under full-light conditions. On balance, this study suggested that warming had a beneficial impact on the early growth and development of conifer seedlings, at least in the short term. Consequently, warming may lead to changes in forest regeneration dynamics and species composition for subalpine coniferous ecosystems under future climate change.

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Although stages T3 and T4 rectal cancer can be reduced to T1 or T2 after neoadjuvant radiochemotherapy, the accuracy of the en-dorectal ultrasonography (ERUS) for the post-radiochemotherapy evalua-tion of low rectal cancer has seldom been reported. We aimed to investigate the value of ERUS in the assessment of invasion staging in low rectal cancer with local progression, and the factors affecting its accuracy, after neoad-juvant radiochemotherapy. A total of 114 patients administered with neo-adjuvant radiochemotherapy for stages II and III low rectal cancer (local stage T3/T4) from February 2018 to December 2020 were enrolled in the study. The changes in local lesions were evaluated using ERUS before and after radiochemotherapy, and compared with the pathological T staging. The accuracy of post-neoadjuvant radiochemotherapy re-staging examined with ERUS was evaluated, and univariate analysis was used to identify the factors affecting the accuracy. After neoadjuvant radiochemotherapy, the blood flow distribution within the lesion significantly declined (P<0.05), the max length and max thickness of the longitudinal axis of the lesion were reduced (P<0.05), and the uT staging was decreased (P<0.05), when compared with lesions before the treatment. Compared with postoperative pathological T staging, the accuracies of ERUS in T1, T2, T3 and T4 stages were 11.11%, 28.57%, 27.27% and 100%, respectively. Univariate analysis indicated that review time of ERUS, post-operative T staging and Wheeler rectal regression stage were factors affecting the accuracy of ERUS re-stag-ing. ERUS is more accurate for T4 re-staging, follow-up reviewed six weeks after neoadjuvant radiochemotherapy and low regression tumors, with a high application value for the assessment of the efficacy of neoadjuvant radiochemotherapy for low rectal cancer.