Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i>
Stump–root systems consist of aboveground stumps and underground coarse roots after timber harvesting. Stump–root systems are the primary source of coarse woody debris (CWD) in plantations, and they play a crucial role in the material cycle, energy flow, and biodiversity of <i>Eucalyptus</i...
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| Format: | Article |
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MDPI AG
2023-12-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/15/1/1 |
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| author | Zhushan Xie Xiang Liang Haiyu Liu Xiangsheng Deng Fei Cheng |
| author_facet | Zhushan Xie Xiang Liang Haiyu Liu Xiangsheng Deng Fei Cheng |
| author_sort | Zhushan Xie |
| collection | DOAJ |
| description | Stump–root systems consist of aboveground stumps and underground coarse roots after timber harvesting. Stump–root systems are the primary source of coarse woody debris (CWD) in plantations, and they play a crucial role in the material cycle, energy flow, and biodiversity of <i>Eucalyptus</i> plantation ecosystems. However, there is limited knowledge about the changes in elemental stock within this CWD type during decomposition. To address this gap, we conducted a study on <i>Eucalyptus urophylla</i> × <i>E. grandis</i> stump–root systems at various times (0, 1, 2, 3, 4, 5, and 6 years) after clearcutting. Our aim was to investigate the stock changes in eight elements (K, Ca, Mg, S, Fe, Mn, Cu, and Zn) within the stumps and coarse roots over time and their decay levels, and we analyzed the relationship between elemental stocks and the physical, chemical, and structural components of stump–root systems. Our findings revealed the following: (1) The majority of each element’s stock within the stump–root system was found in the coarse roots. The elemental stocks in both stumps and coarse roots decreased as time passed after clearcutting and as decay progressed. (2) Notably, the elemental stocks in stumps and coarse roots were significantly higher than in other treatments during the initial 0–2 years after clearcutting and at decay classes I and II. In terms of elemental stocks, stumps from all clearcutting times or decay classes had the highest K stock, followed by Ca and Fe. Mg, Mn, and S stocks were lower than the first three, while Zn and Cu stocks were very low. The ordering of elemental stocks from high to low in the stump–root systems generally aligned with that of the coarse roots. (3) The residual rates of K, Mg, and Mn stocks in the stump–root systems fit the negative exponential model well. It took approximately 1 to 3.5 years for a 50% loss of the initial stocks of these elements and 5 to 10 years for a 95% loss. (4) The large amount of biomass in the stump–root system is the long-term nutrient reservoir of plantations, and any factor related to biomass loss affects the magnitude and duration of the nutrient reservoir, such as N, P, stoichiometric ratios, density, water-holding capacity, and hemicellulose. These findings contribute to a better understanding of the nutrient elemental dynamics and ecological functions of stump–root systems in <i>Eucalyptus</i> plantations. |
| first_indexed | 2024-03-08T10:55:53Z |
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| id | doaj.art-1448d1a8d966457a9b02b62a5a6207b1 |
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| issn | 1999-4907 |
| language | English |
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| publishDate | 2023-12-01 |
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| spelling | doaj.art-1448d1a8d966457a9b02b62a5a6207b12024-01-26T16:30:10ZengMDPI AGForests1999-49072023-12-01151110.3390/f15010001Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i>Zhushan Xie0Xiang Liang1Haiyu Liu2Xiangsheng Deng3Fei Cheng4Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, ChinaGuangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, ChinaGuangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, ChinaGuangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, ChinaGuangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, ChinaStump–root systems consist of aboveground stumps and underground coarse roots after timber harvesting. Stump–root systems are the primary source of coarse woody debris (CWD) in plantations, and they play a crucial role in the material cycle, energy flow, and biodiversity of <i>Eucalyptus</i> plantation ecosystems. However, there is limited knowledge about the changes in elemental stock within this CWD type during decomposition. To address this gap, we conducted a study on <i>Eucalyptus urophylla</i> × <i>E. grandis</i> stump–root systems at various times (0, 1, 2, 3, 4, 5, and 6 years) after clearcutting. Our aim was to investigate the stock changes in eight elements (K, Ca, Mg, S, Fe, Mn, Cu, and Zn) within the stumps and coarse roots over time and their decay levels, and we analyzed the relationship between elemental stocks and the physical, chemical, and structural components of stump–root systems. Our findings revealed the following: (1) The majority of each element’s stock within the stump–root system was found in the coarse roots. The elemental stocks in both stumps and coarse roots decreased as time passed after clearcutting and as decay progressed. (2) Notably, the elemental stocks in stumps and coarse roots were significantly higher than in other treatments during the initial 0–2 years after clearcutting and at decay classes I and II. In terms of elemental stocks, stumps from all clearcutting times or decay classes had the highest K stock, followed by Ca and Fe. Mg, Mn, and S stocks were lower than the first three, while Zn and Cu stocks were very low. The ordering of elemental stocks from high to low in the stump–root systems generally aligned with that of the coarse roots. (3) The residual rates of K, Mg, and Mn stocks in the stump–root systems fit the negative exponential model well. It took approximately 1 to 3.5 years for a 50% loss of the initial stocks of these elements and 5 to 10 years for a 95% loss. (4) The large amount of biomass in the stump–root system is the long-term nutrient reservoir of plantations, and any factor related to biomass loss affects the magnitude and duration of the nutrient reservoir, such as N, P, stoichiometric ratios, density, water-holding capacity, and hemicellulose. These findings contribute to a better understanding of the nutrient elemental dynamics and ecological functions of stump–root systems in <i>Eucalyptus</i> plantations.https://www.mdpi.com/1999-4907/15/1/1coarse woody debrisnutrientsstumpcoarse rootdecomposition<i>Eucalyptus</i> |
| spellingShingle | Zhushan Xie Xiang Liang Haiyu Liu Xiangsheng Deng Fei Cheng Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> Forests coarse woody debris nutrients stump coarse root decomposition <i>Eucalyptus</i> |
| title | Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> |
| title_full | Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> |
| title_fullStr | Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> |
| title_full_unstemmed | Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> |
| title_short | Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of <i>Eucalyptus urophylla</i> × <i>E. grandis</i> |
| title_sort | nutrient element stocks and dynamic changes in stump root systems of i eucalyptus urophylla i i e grandis i |
| topic | coarse woody debris nutrients stump coarse root decomposition <i>Eucalyptus</i> |
| url | https://www.mdpi.com/1999-4907/15/1/1 |
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