Dynamics of stand productivity in Moso bamboo forest after strip cutting

Abstract

Strip cutting can effectively reduce the cutting cost of bamboo forests and promote the transformation and upgradation of bamboo forests through mechanization and modernization. Despite the rapid accumulation of Moso bamboo biomass, the dynamics of five years changes in stand characteristics and productivity after cutting remain unclear. This is critical for formulating efficient bamboo forest management measures. In this paper, plots with an 8 m width strip cut (SC) and respective reserved belts (RB) were selected as the research object, and the traditional management forest (CK) as control. The dynamic characteristics of stand, biomass distribution pattern, and productivity change in the different treatment plots were studied for 5 years after cutting. The results showed that cutting increased the number of shoots and new bamboo, and decreased the diameter at breast height, height to crown base, and height of new bamboo (p<0.05). Cutting reduces the productivity of both SC and RB, and allocates more biomass to the bamboo leaves to capture light in SC (p<0.05). Over time, the characteristics of new bamboo in SC reached the level of CK, and the density of standing bamboo, and productivity, were higher than those in CK. However, the number and productivity of new bamboo decreased significantly in the RB (p<0.05), which reflected the density restriction effect of bamboo forest. Further analysis showed that the increase in productivity in SC and CK was mainly from Moso bamboo at II and III “du”, which positively correlated with the soil contents of total nitrogen, total phosphorus, and available phosphorus. It was suggested that after three On-year restorations, the SC could reach the level of CK, however it is necessary to density manage RB from the second On-year after cutting.

Characteristics of the litter dynamics in a Moso bamboo forest after strip clearcutting

“…However, in high density, increasing the height to crown base and bamboo height is a growth strategy to obtain nutrients, which may also lead to a decrease in bamboo leaf biomass. A previous study has shown that the culm, leaf and branch productivity of RB decreased over time during strip cutting in a Moso bamboo forest ( Zheng et al., 2022b ). In a high-density bamboo forest, there was a decoupling relationship between productivity and soil nutrients, and high density is an important reason for the decline in productivity ( Zheng et al., 2022b ).…”

“…A previous study has shown that the culm, leaf and branch productivity of RB decreased over time during strip cutting in a Moso bamboo forest ( Zheng et al., 2022b ). In a high-density bamboo forest, there was a decoupling relationship between productivity and soil nutrients, and high density is an important reason for the decline in productivity ( Zheng et al., 2022b ). Furthermore, after the formation of new bamboo, the DBH and bamboo height factors remained stable, and the growth rate of dry matter accumulation decreased significantly after the growth of II “du” ( Su, 2012 ).…”

“…The study was conducted on the Yixing forest farm in southern Jiangsu Province, China ( Figure 1 ) ( Zheng et al, 2022b ). The experimental area is within the marine monsoon climate zone in the subtropical region.…”

“…In the first year after cutting, all the bamboos in the SC were new trees, and the reduction of leaf-changing bamboos may also lead to a decrease in litter yield. The high density of RB represents an environment of intense nutrient competition, reflected in the decrease of the number of shoots and bamboo (Zheng et al, 2022b). However, in high density, increasing the height to crown base and bamboo height is a growth strategy to obtain nutrients, which may also lead to a decrease in bamboo leaf biomass.…”

“…The subsequent reductions in new tree quality may reflect the overall degradation in bamboo forest productivity after cutting (Liu, 2009). Our previous study has found that although there was no significant difference in stand density between SC and CK after 5 years, the average bamboo height and average diameter at breast height (DBH) in SC were lower than those in CK (Zheng et al, 2022b). The development of the bamboo forests mainly depends on the nutrient cycling of soil organic matter to maintain fertility (Zheng et al, 2022c).…”