Moderate thinning increases soil nitrogen in a Larix principis-rupprechtii (Pinaceae) plantations
- Published
- Accepted
- Subject Areas
- Ecosystem Science, Soil Science, Biogeochemistry, Forestry
- Keywords
- nitrogen solubility, forests thinning, soil total nitrogen, soil microbial environment
- Copyright
- © 2018 Ma et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Moderate thinning increases soil nitrogen in a Larix principis-rupprechtii (Pinaceae) plantations. PeerJ Preprints 6:e26916v1 https://doi.org/10.7287/peerj.preprints.26916v1
Abstract
Changes in the concentration of soil N or its components of the soil may directly affect forestry ecosystem functioning. Thinning of forest stands, a widely used forestry management practice, may transform soil nutrients directly by altering the soil environment, or indirectly by changing above- or belowground plant biomass. The study objectives were to determine how tree stem density affects the soil N pool and what mechanisms drive any potential changes. In this study, N and its active components were measured beneath a Larix principis-rupprechtii plantation across two entire growing season and under 12 25*25m plots: LT (low thinning forests, removal of 15% of the trees, three plot repetitions), MT (35% removal) and HT (50% removal) and contrast: CK (no thinning control). The environmental index like the light condition, soil reoperation, soil temperatures and prescription was measured in the plots. Results indicated that STN (soil total nitrogen) was affected by tree stem density adjustments in short-term, STN generally increased with decreasing tree stem density, reaching its highest concentration in the MT treatment before decreasing in HT; this pattern was echoed by DON/STN (DON, dissolve organic nitrogen), under MT, a lower DON/STN was measured across the seasons; and MBN (microbial biomass nitrogen) and the SOC/STN (SOC, soil organic carbon) ratios, density treatments had an influence on MBN concentration and inhibited SOC/STN (SOC, soil organic carbon). MT tended to accumulate more STN and produce lower DON/STN and generally higher microbial activity, which may be partly ascribed to the higher MBN value, MBN/STN ratio and lower DON/STN; and the water condition (water content, surface runoff and sediment loads) and light and soil temperatures may partly be responsible to the N pool dynamic in the different density treatments.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
The raw data
The data was collected from spring of 2015 to autumn of 2016, we have collected the data for 2 years
Table supplementary 1 Detailed information before density adjustment
35-year-old Larix principis-rupprechtii was the vegetation type of the sample plots above, all the density adjustment work had been done three years before sampling. The data was collected in July 2012, SOC, TN and pH was the average of 5 soil layers 0- 50 cm.
Table supplementary 2. Species list for the understory vegetation of different thinning treatments
Treatments as in Table 1. Results were collected in 2015 July. NP measns “no presence of”. Importance value = RF + RD + RC, Relative frequency (RF) = (frequency of the specie / the sum of all specie s frequency) *100%; Relative density (RD) = (the number of individual specie / the sum of all species number) *100%; Relative coverage (RC) = (the coverage of an individual specie / the coverage of all plants) *100%.