水生植物分解过程中生态化学计量学特征研究
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摘要
为揭示水生植物分解过程中的生态化学计量学特征,选取沉水植物苦草(Vallisneria natans)和马来眼子菜(Potamogeton malaianus)以及漂浮植物浮萍(Lemna minor),分别置于温室(处理组A、B)和池塘中(处理组C),实验时间为5周,每隔1周随机从各重复组中取1份样品,测定干物质重和总氮(TN)、总碳(TC)、总磷(TP)含量,分析其残存干物质的分解过程。结果表明,在整个分解过程中,3种植物的C/N为7.43~10.06,低于全球水平22.5,C/P为43.09~91.77,明显高于全球水平23.2,说明同一种植物在相同的同化C能力前提下,对N的利用效率较高,对P的利用率较低;N/P为4.71~9.24,小于14,说明植物主要受N的限制。沉水植物苦草和马来眼子菜的C/N在温室和自然条件下规律一致,而漂浮植物浮萍则变化较大,说明沉水植物分解C和N的速率一致且不受环境影响,而漂浮植物浮萍分解C和N受环境影响较大;苦草和浮萍残存干物质C/N在开始有一个快速增长期,说明这2种植物N的释放速率超过C;3种植物残存干物质的C/P和N/P都在第1周快速增长且各处理变化较大,说明3种植物P分解速率都在1周内超过C和N,且受环境影响较大。研究结果将对水生态修复过程中是否移除残存水生植物提供理论依据。
Plant matter from three macrophytes from different environments was dried and analyzed over time to investigate macrophyte stoichiometry during decomposition and the effect of environment on macrophyte stoichiometry.A floating plant,Lemna minor,and two submerged plants,Vallisneria natans and Potamogeton malaianus,were prepared and placed in three water environments: Treatment A: beaker with 200 m L tap water + 3 cm of sediment in a greenhouse; Treatment B: beaker with 200 m L tap water in a greenhouse; Treatment C: in situ in a pond.Each treatment was run in triplicate with six plants per trial. Each week for five weeks,one plant was randomly selected from each treatment for determination of dry weight,TN,TC and TP. The C/N range in the three macrophytes was 7. 43-10. 06,much lower than the global level of 22. 5,and the C/P range was 43. 09-91. 77,significantly higher than the global level of 23. 2. The results indicate that,with the same assimilation capacity of C,the utilization efficiency of N is higher than that of P. The N/P range( 4. 71-9. 24) in the three macrophytes was lower than the global level of 14,showing that N was the limiting nutrient for the macrophytes. Furthermore,the submerged plants V. natans,and P. malaianus exhibited similar C/N ratios in the greenhouse and under natural conditions,indicating a consistent release rate of C and N from the submerged macrophytes and implying a small environmental effect. However,the C/N ratio of L. minor varied markedly between treatments,implying a large environmental effect. The C/N ratio in L. minor and V. natans increased rapidly at the beginning,indicating that the release rate of N from both macrophytes was higher than the release rate of C. The C/P and N/P ratio in the three macrophytes increased rapidly in the first week and the ratios varied significantly among the three groups. This indicates that the P release rate from the three macrophytes was higher than the release rates of C and N during the first week and the environmental effect was significant. This research provides a theoretical basis for the removal of residual aquatic plants during ecological restoration.
Plant matter from three macrophytes from different environments was dried and analyzed over time to investigate macrophyte stoichiometry during decomposition and the effect of environment on macrophyte stoichiometry.A floating plant,Lemna minor,and two submerged plants,Vallisneria natans and Potamogeton malaianus,were prepared and placed in three water environments: Treatment A: beaker with 200 m L tap water + 3 cm of sediment in a greenhouse; Treatment B: beaker with 200 m L tap water in a greenhouse; Treatment C: in situ in a pond.Each treatment was run in triplicate with six plants per trial. Each week for five weeks,one plant was randomly selected from each treatment for determination of dry weight,TN,TC and TP. The C/N range in the three macrophytes was 7. 43-10. 06,much lower than the global level of 22. 5,and the C/P range was 43. 09-91. 77,significantly higher than the global level of 23. 2. The results indicate that,with the same assimilation capacity of C,the utilization efficiency of N is higher than that of P. The N/P range( 4. 71-9. 24) in the three macrophytes was lower than the global level of 14,showing that N was the limiting nutrient for the macrophytes. Furthermore,the submerged plants V. natans,and P. malaianus exhibited similar C/N ratios in the greenhouse and under natural conditions,indicating a consistent release rate of C and N from the submerged macrophytes and implying a small environmental effect. However,the C/N ratio of L. minor varied markedly between treatments,implying a large environmental effect. The C/N ratio in L. minor and V. natans increased rapidly at the beginning,indicating that the release rate of N from both macrophytes was higher than the release rate of C. The C/P and N/P ratio in the three macrophytes increased rapidly in the first week and the ratios varied significantly among the three groups. This indicates that the P release rate from the three macrophytes was higher than the release rates of C and N during the first week and the environmental effect was significant. This research provides a theoretical basis for the removal of residual aquatic plants during ecological restoration.
引文
陈梦琪,郑建伟,蒋跃平,等,2015.沉水植物降解及营养盐释放规律[J].江苏农业科学,43(10):411-413.
黄建军,王希华,2003.浙江天童32种常绿阔叶树叶片的营养及结构特征[J].华东师范大学学报(自然科学版),(3):92-97.
厉恩华,刘贵华,李伟,等,2006.洪湖三种水生植物的分解速率及氮、磷动态[J].中国环境科学,26(6):667-671.
刘兴华,2013.黄河三角洲湿地植物与土壤C、N、P生态化学计量特征研究[D].济南:山东农业大学.
邵梅香,覃林,谭玲,2012.我国生态化学计量学研究综述[J].安徽农业科学,40(11):6918-6920.
熊秉红,李伟,2000.我国苦草属植物的生态学研究[J].武汉植物学研究,18(6):200-508.
叶春,王博,2009.沉水植物黑藻早期分解过程及影响因素研究[J].中国农学通报,25(17):5-10.
张智,刘亚丽,龙腾锐,等,2005.重庆双龙湖水草对营养盐的吸附与释放试验研究[J].资源环境与工程,19(4):305-310.
Agren G I,2004.The CNP stoichiometry of autotrophs-theory and observations[J].Ecology,(7):85-191.
Brock T C M,Huijbregts C A M,Van de Steeg-Huberts M J HA,et al,1982.In situ studies on the breakdown of Nymphoides peltata(Gmel.)O.Kuntze(Menyanthaceae):some methodological aspects of the litter bag technique[J].Hydrobiological Bulletin,16:35-49.
Bryan S G,Annette S,Michael B,2012.C∶N∶P stoichiometry and nutrient limitation of the soil microbial biomass in a grazed grassland site under experimental P limitation or excess[J].Ecological Processes,1(6):1-11.
Elser J J,Fagan W F,Denno R F,et al,2000.Nutritional constraints in terrestrial and freshwater food web[J].Nature,408:578-580.
Elser J J,Sterner R W,Gorokhova E,et al,2000.Biological stoichiometry from genes to ecosystems[J].Ecology Letters,3(6):540-550.
James W F,Barko J W,Field S J,1996.Phosphorus mobilization from littoral sediments of an inlet region in Lake Delavan,Wisconsin[J].Arch Hydrobiolgia,138(2):245-257.
Koerselman W,Meuleman A F M,1996.The vegetation N∶Pratio:a new tool to detect the nature of nutrient limitation[J].Journal of Ecology,33(6):1441-1450.
Manzoni S,Trofymow J A,Jackson R B,et al,2010.Stoichiometric controls on carbon'and phosphorus dynamics in decomposing litter[J].Ecological Monographs,80(1):89-106.
Marichal R,Mathieu J,Couteaux M M,et al,2011.Earthworm and microbe response to litter and soils of tropical forest plantations with contrasting C∶N∶P stoichiometric ratios[J].Soil Biology and Biochemistry,43(7):1528-1535.
Szabo S,Braun M,Nagy P,et al,2000.Decomposition of duckweed(Lemna gibba)under axenic and microbial conditions:flux of nutrients between litter water and sediment the impact of leaching and microbial degradation[J].Hydrobiologia,434:201-210.
Wassen M J,Olde Venterink H G M,De Swart Eoam,1995.Nutrient concentrations in mire vegetation as a message of nutrient limitation in mire ecosystems[J].Journal of Vegetation Science,6:5-16.
黄建军,王希华,2003.浙江天童32种常绿阔叶树叶片的营养及结构特征[J].华东师范大学学报(自然科学版),(3):92-97.
厉恩华,刘贵华,李伟,等,2006.洪湖三种水生植物的分解速率及氮、磷动态[J].中国环境科学,26(6):667-671.
刘兴华,2013.黄河三角洲湿地植物与土壤C、N、P生态化学计量特征研究[D].济南:山东农业大学.
邵梅香,覃林,谭玲,2012.我国生态化学计量学研究综述[J].安徽农业科学,40(11):6918-6920.
熊秉红,李伟,2000.我国苦草属植物的生态学研究[J].武汉植物学研究,18(6):200-508.
叶春,王博,2009.沉水植物黑藻早期分解过程及影响因素研究[J].中国农学通报,25(17):5-10.
张智,刘亚丽,龙腾锐,等,2005.重庆双龙湖水草对营养盐的吸附与释放试验研究[J].资源环境与工程,19(4):305-310.
Agren G I,2004.The CNP stoichiometry of autotrophs-theory and observations[J].Ecology,(7):85-191.
Brock T C M,Huijbregts C A M,Van de Steeg-Huberts M J HA,et al,1982.In situ studies on the breakdown of Nymphoides peltata(Gmel.)O.Kuntze(Menyanthaceae):some methodological aspects of the litter bag technique[J].Hydrobiological Bulletin,16:35-49.
Bryan S G,Annette S,Michael B,2012.C∶N∶P stoichiometry and nutrient limitation of the soil microbial biomass in a grazed grassland site under experimental P limitation or excess[J].Ecological Processes,1(6):1-11.
Elser J J,Fagan W F,Denno R F,et al,2000.Nutritional constraints in terrestrial and freshwater food web[J].Nature,408:578-580.
Elser J J,Sterner R W,Gorokhova E,et al,2000.Biological stoichiometry from genes to ecosystems[J].Ecology Letters,3(6):540-550.
James W F,Barko J W,Field S J,1996.Phosphorus mobilization from littoral sediments of an inlet region in Lake Delavan,Wisconsin[J].Arch Hydrobiolgia,138(2):245-257.
Koerselman W,Meuleman A F M,1996.The vegetation N∶Pratio:a new tool to detect the nature of nutrient limitation[J].Journal of Ecology,33(6):1441-1450.
Manzoni S,Trofymow J A,Jackson R B,et al,2010.Stoichiometric controls on carbon'and phosphorus dynamics in decomposing litter[J].Ecological Monographs,80(1):89-106.
Marichal R,Mathieu J,Couteaux M M,et al,2011.Earthworm and microbe response to litter and soils of tropical forest plantations with contrasting C∶N∶P stoichiometric ratios[J].Soil Biology and Biochemistry,43(7):1528-1535.
Szabo S,Braun M,Nagy P,et al,2000.Decomposition of duckweed(Lemna gibba)under axenic and microbial conditions:flux of nutrients between litter water and sediment the impact of leaching and microbial degradation[J].Hydrobiologia,434:201-210.
Wassen M J,Olde Venterink H G M,De Swart Eoam,1995.Nutrient concentrations in mire vegetation as a message of nutrient limitation in mire ecosystems[J].Journal of Vegetation Science,6:5-16.