Effects of Enclosure Succession on the Morphological Characteristics and Nutrient Content of a Bamboo Whip System in a Moso Bamboo (Phyllostachys edulis) Forest on Wuyi Mountain, China

Abstract

To investigate the morphological characteristics and nutrient content of bamboo whip systems in the Wuyi Mountain Moso bamboo (Phyllostachys edulis) forest in response to enclosure succession. The mixed Moso bamboo forests in the Wuyi Mountain Nature Reserve with 0, 4, 6, 11, 16, and 41 enclosure years were taken as the object of investigation. All the bamboo whips in the 2 m × 2 m sample plots were excavated layer-by-layer according to the soil layers of 0–20 cm, 20–40 cm, and 40–60 cm, and a total of 54 plots were dug. The morphological characteristics and nutrient contents of the Moso bamboo whips in the different soil layers were analyzed and evaluated. Enclosure management measures can not only effectively improve vegetation coverage, biodiversity, and biomass, but also improve soil moisture and nutrient status, indirectly affecting the vegetation, which is of great significance for preventing soil erosion. The results showed that the whip number, whip diameter, flagella number, whip length, and whip weight in the 0–20 cm soil layer were significantly increased by 169.2%, 11.0%, 197.5%, 113.7%, and 109.0% (p < 0.05), respectively, compared with CK after 41 years of enclosure. The average internode length was significantly decreased by 27.9% (p < 0.05) compared to CK after 41 years of enclosure. In the 20–40 cm soil layer, the whip diameter increased by 9.7% after 41 years of enclosure compared with CK, but the whip number, flagella number, whip length, and whip weight were significantly reduced after 16 and 41 years of enclosure compared to CK (p < 0.05). In the 40–60 cm soil layer, the whip number, number of flagella, and whip length increased significantly after 6 and 11 years of enclosure compared with CK (p < 0.05). In the 0–20 cm soil layer, the contents of total nitrogen, total phosphorus, and total potassium in CK were higher than those in other enclosure years, and the soluble sugar content in CK was significantly higher than that in the enclosures of 4, 6, 11, and 41 years by 39.8%, 37.9%, 34.4%, and 34.0% (p < 0.05). The organic carbon content was significantly increased by 14.8%, 12.7%, 7.2%, and 7.1% (p < 0.05) after 4, 6, 11, and 41 years of enclosure compared with CK, respectively. The starch content was significantly increased by 34.1%, 23.0%, and 62.7% (p < 0.05) after 6, 16, and 41 years of enclosure compared with CK, respectively. In the 20–40 cm and 40–60 cm soil layers, the total nitrogen content and soluble sugar content in CK were significantly lower than that in the enclosures of 4 years (p < 0.05), the total phosphorus and total potassium content in CK were significantly higher than that in the enclosures of 41 years (p < 0.05), and the organic carbon content and starch content in CK were significantly higher than that in the enclosures of 6 years (p < 0.05). In summary, enclosure measures were implemented for Moso bamboo forests in the Wuyi Mountain Nature Reserve, which promote the growth of Moso bamboo whips and optimize the structure of bamboo whips.