Litter removal impacts on soil biodiversity and eucalypt plantation development in the seasonal tropics

Journal Article · Thu Sep 01 00:00:00 EDT 2022 · Journal of Forestry Research

DOI:https://doi.org/10.1007/s11676-022-01524-y· OSTI ID:1902909

Inkotte, Jonas ^[1]; Bomfim, Barbara ^[2]; da Silva, Sarah Camelo ^[1]; Valadão, Marco Bruno Xavier ^[1]; da Rosa, Márcio Gonçalves ^[3]; Viana, Roberta Batista ^[1]; Gatto, Alcides ^[1]; Pereira, Reginaldo S. ^[1]

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1. University of Brasilia (Brazil)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
3. SESI/SENAI Social Service Industry, Chapeco (Brazil)

The little layer of tree plantations provides primary nutrients for uptake, buffers changes in soil moisture, and provides habitat and substrate to soil epigeic fauna. However, this layer in eucalypt plantations is often removed to reduce fuel load during the fire season in the Brazilian savanna (Cerrado). Therefore, it is necessary to quantify the effects of changes in litter dynamics on the function of these plantations, on key nutrient cycling processes and on epigeic fauna diversity and abundance. In two adjacent stands (one juvenile and one mature), the consequences of two years of litter removal were quantified as monthly litterfall, leaf and fine wood litter decomposition, epigeic fauna abundance and diversity, soil biogeochemical variables, and tree diameter and basal area increments. Monthly litterfall rates in juvenile and mature stands did not change with litter removal over the study period. Annual litterfall ranged from 4.1 to 4.9 Mg ha^-1a^-1 in litter removal plots and from 3.9 to 4.8 Mg ha^-1a^-1 in control plots. Fine wood litter decomposition was slower in litter removal plots compared to controls, while leaf decomposition rates were similar in both. Two years of litter removal in the juvenile stand did not affect topsoil biogeochemical parameters but decreased available phosphorus at 20–40 cm depth relative to controls. In the mature stand, total cation exchange capacity (0–20 cm) was higher in controls (6.4 cmol_c dm^-3) relative to litter removal plots (6.3 cmol_c dm^-3), while soil moisture (0–40 cm depth) was lower in litter removal (25.45 m³ m^-3) compared to control plots (26 m³ m^-3) in the dry season. A non-metric multidimensional scaling ordination revealed an increased homogeneity in epigeic fauna where litter was removed. Litterfall, decomposition, diameter increment, four soil physical parameters and fourteen chemical parameters at 0–20 and 20–40 cm depth explained the differences in soil epigeic fauna composition between litter removal and control plots. Diameter increment decreased with litter removal only in the juvenile stand, which had reached its growth peak. The results indicate that removing excess litter to decrease fuel volume can alter soil biodiversity and edaphic conditions that negatively affect nutrient cycling and tree growth.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER); Coordination for the Improvement of Higher Education Personnel (CAPES)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1902909
• Journal Information: Journal of Forestry Research, Journal Name: Journal of Forestry Research Journal Issue: 3 Vol. 34; ISSN 1007-662X
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
cerrado
nutrient cycling
plantation management
soil ecology
soil epigeic fauna