OBJECTIVE To reveal the phenotypic differentiation mechanisms and ecological adaptation strategies of the alpine Tibetan medicinal plant Corydalis dasyptera in different habitats.

METHODS A total of 34 survey plots were set up in 4 typical alpine habitats including alpine meadow, scree slope, shady slope and alpine shrub in 7 prefectures and cities of Qinghai Province. Population parameters such as plant height, coverage and density were systematically analyzed, and one-way analysis of variance(ANOVA), principal component analysis(PCA), Bayesian linear mixed models and generalized additive models(GAMs) were integrated for analysis.

RESULTS Habitat type significantly affected the plant height of Corydalis dasyptera, and the overall population exhibited characteristics of low plant height, moderate community coverage, and population density. Two gradients namely growth vitality gradient and environmental stress gradient were extracted by principal component analysis, with a cumulative interpretation rate of 82.5%.The niche differentiation of populations in different habitats was obvious. Plants in shady slope habitats adopted competitive strategies, while those in alpine shrub and scree slope habitats tended to adopt stress-tolerant strategies. Altitude had a non-linear effect on plant growth traits. LOESS regression analysis showed that plant height decreased significantly above 4000 m, and population density presented a unimodal distribution. Bayesian linear mixed model further verified that habitat type was the key influencing factor, with shady slopes exerting a significant positive effect on plant growth(posterior mean=3.69, 95% confidence interval of 0.19, 6.98). There were extremely significant synergistic correlations among plant traits, forming a functional module of “high-quality habitat-high density-large individual”. Populations in screes slopes exhibited high phenotypic plasticity and stronger adaptability to heterogeneous microenvironments.

CONCLUSION This study constructs a continuous spectrum of ecological strategies of Corydalis dasyptera from competitive type to stress-tolerant, providing a theoretical basis for functional ecology of alpine plants and sustainable management of Tibetan medicinal plant resources.