J Plant Res (2016) 129:463–476 DOI 10.1007/s10265-016-0798-z
REGULAR PAPER
Early‑stage changes in natural 13C and 15N abundance and nutrient dynamics during different litter decomposition Mukesh Kumar Gautam1,3 · Kwang‑Sik Lee1 · Byeong‑Yeol Song1,2 · Dongho Lee1 · Yeon‑Sik Bong1
Received: 17 June 2015 / Accepted: 4 December 2015 / Published online: 25 February 2016 © The Botanical Society of Japan and Springer Japan 2016
Abstract Decomposition, nutrient, and isotopic (δ13C and δ15N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/ year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ13C (0.32–6.70 ‰) and δ15N (0.74–3.90 ‰) values of residual
litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.
Electronic supplementary material The online version of this article (doi:10.1007/s10265-016-0798-z) contains supplementary material, which is available to authorized users.
Introduction
* Kwang‑Sik Lee [email protected] Mukesh Kumar Gautam [email protected] 1
Division of Earth and Environmental Science, Korea Basic Science Institute (KBSI), 162 Yeongudanji‑ro, Ochang‑eup, Cheongju, Chungcheongbuk‑do 363‑886, Republic of Korea
2
Chemical Analysis Division, National Forensic Service, Wonju 220‑170, Republic of Korea
3
Present Address: 2081 Wallace Avenue, Bronx, NY 10462, USA
Keywords Carbon isotope · Cool temperate secondary forest · Decay rate · Litter decomposition · Litter nutrient chemistry · Nitrogen isotope
The nutrient dynamics of decomposing litter strongly influence (1) nutrient sustainability in terrestrial ecosystems (Osono and Takeda 2001; Jacob et al. 2010), (2) accretion of organic matter in soil (Aerts 1997; Prescott et al. 2004), and (3) nutrient budgets including carbon (Berg and Laskowski 2005; Hobbie and Högberg 2012). Varying rates of plant litter production, decomposition, and mineralization regulate the supply of most nutrients (Ca, Mg, K, N, and P) needed for forest growth (Osono and Takeda 2004a, b; Fukasawa et al. 2014), and provide most of the energy required for diverse biogeochemical processes driven by saprobiotic organisms (Hobbie and Högberg 2012).
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Information on litter transformation and associated shifts in chemical composition contributes to improved understanding of the role of decomposition in the overall biogeochemistry of forested ecosystems (Aerts 1997). It is particularly critical for forests that are highly dependent on natural fertilization, e.g., woodlands growing on highly weathered soils/rock systems, such as granite or strongly resistant rock systems, where nutrient supply is restricted, and nitrogen and phosphorous cycling processes are conservative. Nutrient recycling via litter decomposition is particularly important across all mechanisms that determine nutrient availabilities for aggrading forests (Prescott et al. 2004; Pandey et al. 2007; Jacob et al. 2010; Xu et al. 2011). The management of forests requires management of litter biomass, which requires a full understanding of decomposition, and nutrient release rates. This information is crucial for the development of planning procedures aiming to sustain nutrient capital, especially in regenerating secondary forests (Ostertag et al. 2008). Although litter fall and decomposition have been extensively studied in cool temperate forests (Berg and Laskowski 2005; Jacob et al. 2010), little information is available for secondary forests and other vegetation (Xuluc-Tolosa et al. 2003; Kim et al. 2012) growing on highly weathered parent material. A fuller understanding of the temporal dynamics of litter chemistry is required for best management approaches to the maintenance, conservation, and development of secondary forests. Forests cover 64 % (6.37 M ha) of South Korea, of which >80 % are secondary in origin and
REGULAR PAPER
Early‑stage changes in natural 13C and 15N abundance and nutrient dynamics during different litter decomposition Mukesh Kumar Gautam1,3 · Kwang‑Sik Lee1 · Byeong‑Yeol Song1,2 · Dongho Lee1 · Yeon‑Sik Bong1
Received: 17 June 2015 / Accepted: 4 December 2015 / Published online: 25 February 2016 © The Botanical Society of Japan and Springer Japan 2016
Abstract Decomposition, nutrient, and isotopic (δ13C and δ15N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/ year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ13C (0.32–6.70 ‰) and δ15N (0.74–3.90 ‰) values of residual
litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.
Electronic supplementary material The online version of this article (doi:10.1007/s10265-016-0798-z) contains supplementary material, which is available to authorized users.
Introduction
* Kwang‑Sik Lee [email protected] Mukesh Kumar Gautam [email protected] 1
Division of Earth and Environmental Science, Korea Basic Science Institute (KBSI), 162 Yeongudanji‑ro, Ochang‑eup, Cheongju, Chungcheongbuk‑do 363‑886, Republic of Korea
2
Chemical Analysis Division, National Forensic Service, Wonju 220‑170, Republic of Korea
3
Present Address: 2081 Wallace Avenue, Bronx, NY 10462, USA
Keywords Carbon isotope · Cool temperate secondary forest · Decay rate · Litter decomposition · Litter nutrient chemistry · Nitrogen isotope
The nutrient dynamics of decomposing litter strongly influence (1) nutrient sustainability in terrestrial ecosystems (Osono and Takeda 2001; Jacob et al. 2010), (2) accretion of organic matter in soil (Aerts 1997; Prescott et al. 2004), and (3) nutrient budgets including carbon (Berg and Laskowski 2005; Hobbie and Högberg 2012). Varying rates of plant litter production, decomposition, and mineralization regulate the supply of most nutrients (Ca, Mg, K, N, and P) needed for forest growth (Osono and Takeda 2004a, b; Fukasawa et al. 2014), and provide most of the energy required for diverse biogeochemical processes driven by saprobiotic organisms (Hobbie and Högberg 2012).
13
464
Information on litter transformation and associated shifts in chemical composition contributes to improved understanding of the role of decomposition in the overall biogeochemistry of forested ecosystems (Aerts 1997). It is particularly critical for forests that are highly dependent on natural fertilization, e.g., woodlands growing on highly weathered soils/rock systems, such as granite or strongly resistant rock systems, where nutrient supply is restricted, and nitrogen and phosphorous cycling processes are conservative. Nutrient recycling via litter decomposition is particularly important across all mechanisms that determine nutrient availabilities for aggrading forests (Prescott et al. 2004; Pandey et al. 2007; Jacob et al. 2010; Xu et al. 2011). The management of forests requires management of litter biomass, which requires a full understanding of decomposition, and nutrient release rates. This information is crucial for the development of planning procedures aiming to sustain nutrient capital, especially in regenerating secondary forests (Ostertag et al. 2008). Although litter fall and decomposition have been extensively studied in cool temperate forests (Berg and Laskowski 2005; Jacob et al. 2010), little information is available for secondary forests and other vegetation (Xuluc-Tolosa et al. 2003; Kim et al. 2012) growing on highly weathered parent material. A fuller understanding of the temporal dynamics of litter chemistry is required for best management approaches to the maintenance, conservation, and development of secondary forests. Forests cover 64 % (6.37 M ha) of South Korea, of which >80 % are secondary in origin and
