The overall decomposition of the spring-lodged litter is faster than the autumn-lodged litter in a steppe ecosystem
Abstract
In grasslands, a large proportion of senescent plant shoots in autumn pass the winter period as standing dead materials instead of becoming detached litter immediately. However, the information is hardly available on the decomposition of plant standing dead materials during the winter period and its impacts on the subsequent decomposition of these materials after littering in the coming spring. We conducted a two-year experiment to compare the decomposition process of the litters lodged in autumn versus that lodged in spring of two dominant plant species, Leymus chinensis and Stipa grandis, in a native steppe ecosystem in Inner Mongolia. Throughout the whole decomposition period, the autumn-lodged litter was directly positioned upon the soil surface, while the spring-lodged litter suspended as standing dead for the first 7 months in the autumn and winter period before being detached. We found that the overall decomposition rate of spring-lodged litter was faster than that of autumn-lodged litter over the experimental period. The decomposition rate was correlated positively with the N content, but negatively with the C/N ratio, lignin concentration and lignin/N ratio in litters. The spring-lodged litter showed a sharp decrease in lignin remaining during the standing-dead stage, while the autumn-lodged litter did not, which suggested an important role played by photodegradation in the breakdown of lignin over the winter period that facilitated the litter decomposition in subsequent stages. These findings highlight the difference in the decomposition rates of the litters lodged in autumn versus in spring, and suggest it important to incorporate the effects of the standing-dead stage on litter decomposition in calculating or modeling the nutrient turnover rates in semi-arid steppe ecosystems.
Dataset DOI: 10.5061/dryad.wwpzgmszh
Description of the data and file structure
Litter type: Represents the seasonal type of litter, classified according to the exposure conditions before the litter comes into contact with the ground and begins decomposition.
“Spring” — Refers to litter that remains standing for approximately seven months before falling to the ground. During this period, it undergoes a photodegradation phase under sunlight exposure, after which it contacts the soil surface and begins decomposition.
“Autumn”— Refers to litter that falls directly to the ground in autumn without a prior sunlight exposure phase, and its decomposition occurs entirely on the soil surface.
Month: The month or time point at which samples were collected, indicating decomposition duration.
State: Divide the months mentioned above by 12 to convert them into years.
Litter_species: The plant species that produced the litter, such as Leymus chinensis or Stipa grandis
Block: The replicate number used in the experimental design.
Mass_loss_%: Percentage of initial dry mass lost during decomposition; represents the decomposition rate.
Initial_C_%: The initial organic carbon concentration in the litter.
Initial_N_%: The initial total nitrogen concentration in the litter.
Intial_C_and_N_ratio: The ratio of total carbon to total nitrogen at the beginning of decomposition
Initial_Hemicellulose_%: The initial hemicellulose concentration in the litter.
Initial_cellulose_%: The initial cellulose concentration in the litter.
Initial_Lignin_%: The initial lignin concentration in the litter.
Initial_Lignin_and_N_ratio: The initial lignin and N ratio in the litter.
Remaining_mass_%: Fraction of dry mass remaining after decomposition
N_%: Total nitrogen concentration in the remaining litter after a certain decomposition period.
C_%: Total carbon concentration in the remaining litter after a certain decomposition period.
C_and_N_ratio: Total carbon and nitrogen ratio in the remaining litter after a certain decomposition-n period.
Hemicellouse_%: Hemicellulose concentration in the remaining litter after a certain decomposition period.
Cellulose_%: Cellulose concentration in the remaining litter after a certain decomposition period.
Lignin_%: Lignin concentration in the remaining litter after a certain decomposition period.
Lignin_and_nitrogen_ratio: Lignin_and_nitrogen_ratio in the remaining litter after a certain decomposition period.
Remaining_C_%: Fraction of carbon remaining after decomposition, indicates carbon retention.
Remaining_N_%: Fraction of nitrogen remaining after decomposition, indicates carbon retention.
Remaining_hemicellulose_%: Fraction of hemicellulose remaining after decomposition, indicates carbon retention.
Remaining_cellulose_%: Fraction of cellulose remaining after decomposition, indicates carbon retention.
Remaining_lignin_%: Fraction of lignin remaining after decomposition, indicates carbon retention.