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It is of great significance to popularize and apply nanotechnology in forest plantations for the high-quality development of such areas. Camphor trees have good ecological and environmental benefits and are economic, which makes them worthy of widespread popularization and promotion. In this paper, we successfully synthesized bulk and rod-like TiO2 powder and used it to study the influence of camphor seed germination and seedling growth. The germination rate, germination potential, germination index activity index of camphorwood seed during germination were measured by TiO2 solution with different morphology. Meanwhile, the fresh weight, root length and seedling height of seedlings, as well as the activities of CAT, SOD and POD and MDA content in the seedlings were measured in detail. The difference in the promoting effect between bulk and rod TiO2 powder was compared. The possible reasons are also explained. The results showed that bulk and rod-like TiO2 solution improved the activities of SOD, POD and CAT, and increased the resilience of camphor seedlings. Moreover, the rod-like TiO2 solution has a stronger osmotic effect on seed, and has a better effect on promoting seed germination and seedling growth. The study on the influence of nano-TiO2 concentration also further showed that the treatment of nano-TiO2 solution with appropriate concentration could effectively promote seed germination and seedling growth, and enhance its adoptability to adversity; but excessive concentration will bring some side effects, which was not conducive to seed germination and seedling growth. In general, the results of this study provide a theoretical basis and technical guidance for the practical application of nanotechnology in camphor seedling and afforestation production.

Based on field investigation and relevant information about Daxiong Mountain, we do the area types analysis of the seed plant. The results showed that: (1) There were1218 species of seed plants in this region, belong to 166 families and 668 genera, including 6 families, 11 genera, 14 species of gymnosperm and 160 families, 657 genera, 1204 species of angiosperms. (2) The composition of the seed plants in this region was highly dispersed and very complex. In the composition of the families, the number of small families was the most, which rate was 40.00%. However, the major families contains the largest number of plant species, the rate was 34.51%. In the composition of the genus, species focus on the small genera and the single genus that accounted for 37.14% and 51.43%. (3) The flora of seed plants in this region was complex. There were 267 genera, 46.05% genera of the total, in the tropical distribution. Followed by the temperate distribution of 171 genera, accounting for 28.24%. In addition, the Asian distribution including 168 genera, 27.71% of the total and the world distribution including 62 genera, accounting for 9.28% of the total.

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Soil depth, slope position and different plantations can influence bacterial community composition in Camellia oleifera forests. However, prior studies have focused on the impacts of different depths, slope positions, and forest types on bacterial diversity independently, without comparing their combined impacts. This study aimed to assess variation in soil bacterial community structures according to soil depth and slope position and different forest types in the same plot. The composition of soil bacterial communities was evaluated using high-throughput sequencing of the 16S rRNA gene. Results indicate that the soil organic carbon, humus, and total organic content increased, and the bacterial composition and structure were significantly altered in response to the G. jasminoides + C. oleifera low-yielding forest in comparison to the other three forest types. The highest soil bacteria numbers, Alpha and beta diversity, which improved the soil microecological environment, were associated with the G. jasminoides + C. oleifera forests and not the depth or slope position treatments. The slope position did not have a significant influence on the soil physicochemical and bacterial properties. Structural equation modeling suggested that G. jasminoides + C. oleifera significantly affected the soil bacterial community diversity by mediating the soil pH and NH –N. The effects of forest type on soil bacterial diversity were more important than soil depth and slope position. This specific intercropping system was found to be an effective strategy to improve soil health.