Authors:ZHANG Ye1,2,LEI Zeyong1,2*,ZHAO Guojun3,ZHOU Fengyan1,YANG Xiaohong4,YANG Yuxin1
Units: 1. School of Environmental Science and Engineering, Liaoning Technical University, 2. Institute of Ecological Management of Degraded Land, Liaoning Technical University, 3. Liaoning Institute of Sandy Land Management and Utilization, 4. Qingsongling Forest Farm, Jianping County, Liaoning Province
Introduction:ZHANG Ye, male, from Fuxin, Liaoning Province, master candidate, research direction: forest ecology. *Corresponding author, professor, engaged in forest ecology research.
Funds: National Natural Science Foundation of China (31570709).
Source: Anhui Agricultural Sciences, Issue 6, 2024
Citation format: ZHANG Ye, LEI Zeyong, ZHAO Guojun, et al.Study on the content characteristics and influencing factors of leaf litter in P. sylvestris var.
OSID Open Science Program
Long press to identify the exclusive QR code of the paper, listen to the author talk about the background of the paper writing, and exchange experiences with peers.
Forest litter plays an important role in nutrient cycling in ecosystems and is essential for nutrient cycling and forest productivity. Litter is gradually converted into organic matter and nutrients in the soil through the decomposition of microorganisms, fungi and other organisms, as well as chemical processes in the environment. The rate of decomposition of litter is influenced by climate, basic properties of litter, and litter decomposers. Among them, lignin, cellulose and hemicellulose in litter are refractory substances and have an important impact on the decomposition rate. Lignin gives plants structural stability and the ability to resist the external environment, cellulose provides mechanical support and a bridge for cell-to-cell communication, and hemicellulose is rich in energy and nutrients. These compounds are the main components that make up plant cell walls and affect litter decomposition rates, nutrient cycling, and soil quality by providing structural support, resisting decomposers, regulating water, and releasing nutrients.
Pinus sylvestris var. mongolica is a key afforestation tree species in northern China, mainly distributed in the mountainous areas of the Daxing'an Mountains of mainland China and the sandy areas of southwest Hailar. Although Pinus sylvestris var. mongolica plantations have great ecological and economic value in the Sanbei region, the growth rate is accelerated, the life cycle is shortened, and the maturity period is advanced after being introduced to Zhanggutai (the maximum growth is reached at the 47th year on average, that is, the maturity age of the number of trees). However, the nutrient input of the mature forest of Pinus sylvestris var. mongolica mainly depends on litter decomposition, and leaf litter accounts for the largest proportion. The analysis of lignin, cellulose and hemicellulose content changes in leaf litter is of great significance for revealing key processes such as carbon cycling, nutrient supply and biodiversity in this stand ecosystem.
objective
To reveal the change mechanism and influencing factors of the "three major elements" (lignin, cellulose and hemicellulose) in the mature forest of Pinus sylvestris var.
way
In this study, the dynamics and influencing factors of the content of the "three major elements" in leaf litter were analyzed in the mature Pinus sylvestris var. mongolica plantation in Zhanggutai Town, Zhangwu County, Liaoning Province (the stand growth stages were 43, 49 and 65 years, and the stand density was 400, 625 and 800 trees/hm2, 3 replicates each).
The average annual temperature of the study site is 6.1°C, the annual precipitation is 450~500mm, mainly concentrated in June to August, the annual evaporation is 1200~1450mm, and the annual average wind speed is 3.8m/s (Fig. 1). The basic situation of the standard plot of Pinus sylvestris var. mongolica plantation mature forest is shown in Table 1.
Fig. 1 Trends of monthly precipitation, monthly mean temperature, monthly mean wind speed and monthly maximum wind speed in the study area in 2021
outcome
◆Dynamic characteristics of the content of the "three major elements" in leaf litter
It can be seen from Figure 2 that the dynamic variation of lignin in leaf litter showed a bimodal pattern, with the peak value in March (405.33 g/kg) and July (432.44 g/kg), respectively, and the lowest value in January (158.44 g/kg). From November to March of the following year, the lignin content showed an upward trend and increased greatly, while the lignin content showed a downward trend from March to June and July to November, but the decline was relatively slow from July to November. The cellulose was multimodal, with peaks of 380.34, 377.98 and 361.53 g/kg in March, September and November, respectively, and the lowest value of the year appeared in February. From February to March, the cellulose content increased sharply, showed a downward trend from March to July, and the decline was slow, first increased and then decreased from July to October, and decreased from November to December.
Fig.2 Dynamic characteristics of the "three major elements" in leaf litter
Hemicellulose also showed a multimodal type, with peaks of 345.04, 297.90, 343.73 and 364.86 g/kg in January, March, August and October, respectively. The lower hemicellulose content appeared in February and September, which were 174.71 and 176.86g/kg, respectively, and the hemicellulose content decreased sharply in February and September, with little change from March to August, and showed a downward trend from October to December, and the decline rate slowed down in December.
As the three main components of leaf litter, lignin, cellulose and hemicellulose all had a peak in March and a relatively low value in February. From March to June, the contents of these three components showed a trend of first decreasing, then increasing and then decreasing. In July, the content difference of the three components was the largest, which were lignin (432.44 g/kg), cellulose (222.34 g/kg) and hemicellulose (343.08 g/kg). The annual mean values of leaf litter in Pinus sylvestris var. sylvestris var. sylvestris var. sylvestris var. sylvestris ±>±>±var. sylvestris
◆Effects of stand growth and stand density differences on the content of the "three major elements" in leaf litter
From the analysis of variance in Table 2, it was found that stand growth, stand density and their interactions had no significant effects on the lignin, cellulose and hemicellulose contents of leaf litter (P>0.05).
It can be seen from Fig. 3 that the mean lignin content of leaf litter at 400, 625 and 800 trees/hm2 stand densities were 275.22, 307.94 and 363.07 g/kg, the mean cellulose content was 311.85, 292.40 and 270.87 g/kg, and the mean hemicellulose content was 256.77, 263.16 and 328.09 g/kg, respectively. From the average values of the three components, the lignin and hemicellulose contents were the highest at the stand density of 800 plants/hm2, and the highest cellulose content at the stand density of 400 plants/hm2. With the growth of stands, the lignin content decreased first and then increased at the density of 400 trees/hm2 stand, the cellulose content decreased slightly, and the hemicellulose content increased first and then decreased. Under the density of 625 trees/hm2 stands, the lignin content decreased first and then increased, the cellulose content decreased gradually, and the hemicellulose content increased gradually. The lignin content increased first and then decreased at the density of 800 plants/hm2, the cellulose content showed a downward trend, and the decrease was the most obvious, and the hemicellulose content showed a gradual increase trend, but the increase was not as obvious as that of 625 plants/hm2. At the same time, with the increase of stand density, the lignin content of 43 and 49a litter showed an upward trend, the cellulose content did not decrease significantly, the hemicellulose content decreased first and then increased, the lignin content of 65a increased first and then decreased, the cellulose content decreased gradually, and the hemicellulose content increased gradually.
Note: Different uppercase letters indicate significant differences in density at the same stand growth stage (P<0.05). Different lowercase letters indicated significant differences among the growth stages of different stands at the same density (P<0.05).
Fig.3 The contents of the "three major elements" in leaf litter under the difference of stand density and stand growth
◆Correlation analysis between the "three major elements" and climatic factors in leaf litter
From the correlation analysis results in Table 3, the following relationship can be observed: the monthly average wind speed was negatively correlated with leaf litter lignin, cellulose and hemicellulose, while the monthly maximum wind speed was only positively correlated with the lignin content of leaf litter (P<0.05), which was positively correlated with cellulose and hemicellulose, the number of occurrences of maximum wind speed was positively correlated with the "three major elements" of leaf litter, the monthly precipitation was positively correlated with the lignin content of leaf litter, and negatively correlated with the content of cellulose and hemicellulose, and the monthly average temperature was negatively correlated with the lignin and hemicellulose content of leaf litter, and positively correlated with the cellulose content. However, among the five climate factors, the correlation coefficient between monthly maximum wind speed and lignin was the largest, and the correlation coefficient between monthly average wind speed and maximum wind speed and lignin was the smallest.
conclusion
Leaf litter lignin, cellulose and hemicellulose all peaked in March and had relatively low values in February. From March to June, the contents of these three components showed a trend of first decreasing, then increasing and then decreasing. In July, the content difference of the three components was the largest, which were lignin (432.44 g/kg), cellulose (222.34 g/kg) and hemicellulose (343.08 g/kg). From October to December, the contents of these three components showed a downward trend as a whole. Stand growth, stand density and their interactions had no significant effects on the lignin, cellulose and hemicellulose contents of leaf litter (P>0.05). However, from the average value of the contents of the three components, the lignin and hemicellulose contents were the highest at the stand density of 800 plants/hm2, and the cellulose content was the highest at the density of 400 plants/hm2 stand, and the changes of the contents of the three components were different under different stand densities and growth conditions. There was a significant positive correlation between the monthly maximum wind speed and the lignin content of P. sylvestris var. mongolica (P<0.05).
More Recommended Papers
A comprehensive evaluation of new millet varieties and their lightweight, simple and efficient production technologies
Induction and isolation of mealworm antimicrobial peptides and their antimicrobial activity
Isolation and degradation characteristics of cyfluthrin-degrading bacteria
Paper Recommendation|New Farmer Short Video Communication Mechanism, Improving Dilemma and Alleviation Strategy
Preparation and characterization of Sanpolyphenol microcapsules
Analysis and countermeasures of Guangxi's leading agricultural economic and industrial development
Research on the high-quality development of agricultural productive service industry empowered by digital economy
Tissue culture study of diploid pale stems
Suggested Papers|Analysis of the population structure and conservation priority of local chickens in China based on whole-genome resequencing
Effects of drought stress on growth traits of different maize varieties at different growth stages
- Editor: Xiaobai
- Typesetting: Xiaotong