Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity
Abstract Background The forest-steppe ecotone, a critical transition zone sensitive to global change, faces increasing nitrogen deposition. However, the interplay between nitrogen conversion processes and soil enzyme activity remains unclear. We investigated the effects of nitrogen addition on plant...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2025-04-01
|
| Series: | Ecological Processes |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13717-025-00598-w |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850184426437214208 |
|---|---|
| author | Baihui Ren Haoyan Li Daiyan Li Meng Meng Jiahuan Li Long Bai Yulong Feng |
| author_facet | Baihui Ren Haoyan Li Daiyan Li Meng Meng Jiahuan Li Long Bai Yulong Feng |
| author_sort | Baihui Ren |
| collection | DOAJ |
| description | Abstract Background The forest-steppe ecotone, a critical transition zone sensitive to global change, faces increasing nitrogen deposition. However, the interplay between nitrogen conversion processes and soil enzyme activity remains unclear. We investigated the effects of nitrogen addition on plant nutrient dynamics, microbial functional genes, and enzyme activity in northwest Liaoning, China. Results Nitrogen addition significantly increased leaf nitrogen content in Potentilla tanacetifolia (peak under N40) and Artemisia frigida (peak under N40), while Lespedeza daurica showed a non-linear response (peak under N20). Phosphorus content remained unaffected across species. Soil enzyme activities (urease, nitrate reductase, dehydrogenase) increased with nitrogen input, with protease activity rising proportionally to nitrogen addition rate. Functional genes (nirK, nifH, AOB-amoA) exhibited dynamic responses: nirK abundance peaked under N40, nifH under N10, and AOB-amoA increased with nitrogen input. Structural equation modeling revealed that nirK gene abundance positively influenced enzyme activity (λ = 0.512), while nifH negatively correlated with leaf N/P ratios (λ = −0.606). Soil protease activity directly drove leaf N/P ratios (λ = 0.734). Conclusions Nitrogen addition enhances plant nitrogen uptake and enzyme-driven mineralization, but species-specific responses highlight ecological trade-offs. Soil pH and protease activity are pivotal in mediating nitrogen conversion and plant nutrient stoichiometry. These findings underscore the need to integrate microbial and enzymatic dynamics into nutrient management strategies for ecotones under nitrogen enrichment. |
| format | Article |
| id | doaj-art-7b83a00b37da4f658332988b18cb1fa0 |
| institution | OA Journals |
| issn | 2192-1709 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Ecological Processes |
| spelling | doaj-art-7b83a00b37da4f658332988b18cb1fa02025-08-20T02:17:04ZengSpringerOpenEcological Processes2192-17092025-04-0114111310.1186/s13717-025-00598-wNitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activityBaihui Ren0Haoyan Li1Daiyan Li2Meng Meng3Jiahuan Li4Long Bai5Yulong Feng6Plant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityPlant Protection College, Shenyang Agricultural UniversityAbstract Background The forest-steppe ecotone, a critical transition zone sensitive to global change, faces increasing nitrogen deposition. However, the interplay between nitrogen conversion processes and soil enzyme activity remains unclear. We investigated the effects of nitrogen addition on plant nutrient dynamics, microbial functional genes, and enzyme activity in northwest Liaoning, China. Results Nitrogen addition significantly increased leaf nitrogen content in Potentilla tanacetifolia (peak under N40) and Artemisia frigida (peak under N40), while Lespedeza daurica showed a non-linear response (peak under N20). Phosphorus content remained unaffected across species. Soil enzyme activities (urease, nitrate reductase, dehydrogenase) increased with nitrogen input, with protease activity rising proportionally to nitrogen addition rate. Functional genes (nirK, nifH, AOB-amoA) exhibited dynamic responses: nirK abundance peaked under N40, nifH under N10, and AOB-amoA increased with nitrogen input. Structural equation modeling revealed that nirK gene abundance positively influenced enzyme activity (λ = 0.512), while nifH negatively correlated with leaf N/P ratios (λ = −0.606). Soil protease activity directly drove leaf N/P ratios (λ = 0.734). Conclusions Nitrogen addition enhances plant nitrogen uptake and enzyme-driven mineralization, but species-specific responses highlight ecological trade-offs. Soil pH and protease activity are pivotal in mediating nitrogen conversion and plant nutrient stoichiometry. These findings underscore the need to integrate microbial and enzymatic dynamics into nutrient management strategies for ecotones under nitrogen enrichment.https://doi.org/10.1186/s13717-025-00598-wNitrogen additionPlant nitrogen and phosphorus ratioEnzyme activityNitrogen transformationFunctional gene of nitrogen transformation |
| spellingShingle | Baihui Ren Haoyan Li Daiyan Li Meng Meng Jiahuan Li Long Bai Yulong Feng Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity Ecological Processes Nitrogen addition Plant nitrogen and phosphorus ratio Enzyme activity Nitrogen transformation Functional gene of nitrogen transformation |
| title | Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| title_full | Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| title_fullStr | Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| title_full_unstemmed | Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| title_short | Nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| title_sort | nitrogen addition changes the nitrogen conversion process in forest steppe ecotone by increasing enzyme activity |
| topic | Nitrogen addition Plant nitrogen and phosphorus ratio Enzyme activity Nitrogen transformation Functional gene of nitrogen transformation |
| url | https://doi.org/10.1186/s13717-025-00598-w |
| work_keys_str_mv | AT baihuiren nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT haoyanli nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT daiyanli nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT mengmeng nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT jiahuanli nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT longbai nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity AT yulongfeng nitrogenadditionchangesthenitrogenconversionprocessinforeststeppeecotonebyincreasingenzymeactivity |