Abstract: The pruning residues of Camellia sinensis and the litter of associated tree species are crucial components of tea gardens, the decomposition processes of which are closely related to soil nutrients and thus play a significant role in regulating nutrient cycling and energy flow. Using the litterbag decomposition method, we investigated the nutrient changes and energy flow processes during the decomposition of pruning residues from Camellia sinensis and associated tree species, including Cinnamomum glanduliferum, Betula luminifera, Cunninghamia lanceolata, and Pinus massoniana, in the central Guizhou ecological tea garden. The results showed that the decomposition rate of broadleaf tree species residues was significantly higher than that of coniferous species, with an order of Betula luminifera > Cinnamomum glanduliferum > tea pruning residues > Pinus massoniana > Cunninghamia lanceolata. The total carbon, total nitrogen, and calorific value of plant residues showed direct release. Total phosphorus exhibited direct release in Betula luminifera but accumulation patterns in Cinnamomum glanduliferum and Pinus massoniana. Total potassium demonstrated direct release in broadleaf species and Cunninghamia lanceolata, but showed accumulation in the later stages of decomposition (360 days) in Pinus massoniana. The lignin content generally showed net accumulation. Furthermore, there was a significant positive correlation between the release of calorific value and the release of total carbon, total nitrogen, and total potassium during decomposition (P<0.05). Among the five residues, Betula luminifera exhibited the highest decomposition rate, with the best performance in nutrient return and energy release. Nutrient release significantly influenced the release of calorific value, particularly carbon and nitrogen elements. The findings reveal the characteristics of material cycling and energy flow in the tea gardens, providing scientific evidence for the plant configuration and the rational utilization of plant residues in ecological tea gardens in mountainous areas of Guizhou.

Key words: ecological tea garden, plant residue, nutrient cycling, calorific value, energy flux