The root is the main organ of a plant for absorbing resources and whose spatial distribution characteristics play an important role in the survival of seedlings after afforestation. Chinese fir (Cunninghamia lanceolata) is one of China’s most important plantation species. To clarify the effects of propagation methods on root growth and spatial distribution characteristics of Chinese fir trees, sampled trees cultivated by seed germination, tissue culture, and asexual cutting of Chinese fir were taken as the research objects. The root morphology, geometric configuration, and spatial distribution characteristics of different trees were analyzed. The influence of geometric root morphology on its spatial distribution pattern was explored by correlation analysis, and the resource acquisition characteristics reflected by the roots of Chinese fir trees with different propagation methods are discussed. The main results showed that the root mean diameter (1.56 mm, 0.95 mm, and 0.97 mm), root volume (2.98 m³, 10.25 m³, and 4.07 m³), root tip count (397, 522, and 440), main root branch angle (61°, 50° and 32°) and other geometric configurations of Chinese fir under seed germination, tissue culture and rooted cutting respectively, were significantly different, which resulted in different distribution characteristics of roots in space. Chinese fir seed germination had noticeable axial roots, and the growth advantage was obvious in the vertical direction. A fishtail branch structure (TI = 0.87) was constructed. The shallow root distribution of tissue culture and rooted cutting was obvious, and belonged to the fork branch structure (TI = 0.71 and 0.74, respectively). There was a tradeoff in the spatial growth of the root system of Chinese fir trees with different propagation methods to absorb nutrients from heterogeneous soil patches. A negative correlation was present between the root system and root amplitude. There was an opposite spatial growth trend of Chinese fir trees with different propagation methods in the vertical or horizontal direction. In conclusion, selecting suitable propagation methods to cultivate Chinese fir trees is beneficial to root development and the “ideal” configuration formation of resource acquisition to improve the survival rate of Chinese fir afforestation.

Fine root traits and their relationships reflect the ecological trade-off strategies of plants in resource investment and are important for understanding the life strategies and growth of plants in response to changes in the environment. We used 16-year-old Chinese fir (Cunninghamia lanceolata Lamb. Hook.) plantations with different slope positions as the research object to explore the morphological, anatomical, and chemical properties of fine roots and their relationships. With increasing root order levels, the morphological, anatomical, and chemical traits of the fine roots of Chinese fir at different slope positions showed similar change trends; however, at the same order level, the differences were large. Under the upper slope site conditions, the average diameter of the second- and third-order roots and the thickness of the third-order root cortex were the highest. However, specific surface area, vascular bundle diameter, and the ratio of third-order roots were higher under the middle-slope site conditions. Under the lower slope site conditions, the specific surface area and specific root length of first-order roots and the root ratio of second-order roots were the highest. The biomasses of the first- and third-order roots on the middle and lower slopes were higher than those on the upper slope. The contents of N and P in fine roots of grades 1–3 Chinese fir showed the order of lower slope > middle slope > upper slope; however, the changes in C/N and C/P ratios showed the opposite trend, indicating differences in the morphological, anatomical, and chemical properties as well as resource acquisition strategies of fine roots of grades 1–3 Chinese fir under different slope positions. There were negative correlations between fine root diameter, N and P contents, and specific root length, indicating an acquisition and conservative resource trade-off relationships between fine root morphological, anatomical, and chemical traits. There were also differences in the relationships between the morphological, anatomical, and chemical traits of Chinese fir fine roots at different slope positions, indicating that the relationships between these traits were affected by slope position change. Chinese fir varieties with root-foraging characteristics ranging from resource conservation to resource acquisition can be selected for planting to improve the productivity of C. lanceolata plantations.