1. 毕业设计（论文）的内容和要求

研究简介：植物碳同位素组成（δ13c）是一个综合生理生态指标，反映了植物气孔导度与光合效率之间的平衡，能够指示植物的水分利用效率和植物的生态策略。

而氮是植物必需的营养元素，控制和调节植物的光合作用，因此，植物δ13c与植物n含量之间应该存在一定的关系。

研究植物δ13c和植物氮含量之间的关系在植物生理生态学有一定的意义。

2. 参考文献

1. Aparicio N, Araus JL, Royo C, Villegas D. Carbon isotope discrimination, canopy temperautre depression and nitrogen content as tools for grain yield assessment in Mediterranean conditions. In: Royo C (ed.), Nachit M (ed.), Di Fonzo N (ed.), Araus JL (ed.). Durum wheat improvement in the Mediterranean region: New challenges. Zaragoza: CIHEAM; 2000. pp.181#8211;184 2. Chen ZX, Wang GA, Jia YF. Foliar δ13C showed no altitudinal trend in an arid region and atmospheric pressure exerted a negative effect on plant δ13C. Frontiers in Plant Science, 2017,doi:10.3389/fpls2017.01070. 3. Cordell S, Goldstein G, Meinzer FC, Handley LL. Allocation of nitrogen and carbon in leaves of Metrosiderospolymorpha regulates carboxylation capacity and δ13C along an altitudinal gradient. Functional Ecology.1999; 13: 811#8211;818 4. Domingues TF, Meir P, Feldpausch TR, Saiz G, Veenendaal EM, Schrodt F, et al. Co-limitation of photosynthetic capacity by nitrogen and phosphorus in West Africa woodlands. Plant, Cell amp; Environment.2010; 33: 959#8211;980 5. Duursma RA and Marshall JD. Vertical canopy gradients in δ13C correspond with leaf nitrogen content in a mixed- species conifer forest. Tree. 2006; 20: 496#8211;506 6. Hikosaka K. Interspecific difference in the photosynthesis- nitrogen relationship: patterns, physiological causes, and ecological importance. J Plant Res. 2004; 117: 481#8211;494 doi: 10.1007/s10265-004-0174-2 PMID: 15583974 7. Huang WJ, Houlton BZ, Marklein AR, Liu JX, Zhou GY. Plant stoichiometric responses to elevated CO2 vary with nitrogen and phosphorus inputs: Evidence from a global-scale meta-analysis. Scientific Reports. 2015; 5:18225, doi: 10.1038/srep18225 PMID: 26656752 8. Hultine DR and Marshall JD. Altitude trends in conifer leaf morphology and stable carbon isotope composition. Oecologia. 2000; 123: 32#8211;40. 9. Li JZ, Wang GA, Zhang RN, Li L. A Negative Relationship between Foliar Carbon Isotope Composition and Mass-Based Nitrogen Concentration on the Eastern Slope of Mount Gongga, China. PLoS ONE. 2016, DOI:10.1371/journal.pone.0166958. 10. Lloyd J, Bloomfield K, Domingues TF, Farquhar GD. Photosynthetically relevant foliar traits correlating better on a mass vs an area basis: of ecophysisological relevance or just a case of mathematical imperatives and statistical quicksand? New Phytology. 2013; 199: 311#8211;321 doi: 10.1111/nph.12281 PMID:23621613 11. Reich PB and Walters MB. Photosynthesis- nitrogen relations in Amazonia tree species. II. Variation in nitrogen vis-#224;-vis specific leaf area- influences mass and area- based expressions. Oecologia. 1994:97: 73#8211;81. 12. Reich PB, Ellsworth DS, Walters MB. Leaf structure (specific leaf area) modulates photosynthesis nitrogen relations: evidence from within and across species and functional groups. Functional Ecology. 1998; 12:948#8211;958 13. Sistla SA and Schimel JP. Stoichiometric flexibility as a regulator of carbon and nutrient cycling in terrestrial ecosystems under change. New Phytology. 2012; 196: 68#8211;78 doi: 10.1111/j.1469-8137.2012.04234.x PMID: 22924404 14. Tan QQ, Li JZ, Chen ZX, Wang GA, Jia YF, Yao HY, Han WX. Minimizing the effect of precipitation in clarifying the responses of leaf N and P stoichiometry to temperature. Environmental Pollution.2018; 243: 404-409 15. Watkins JM, Rundel PW Jr, Cardelus CL. The influence of life forms on carbon and nitrogen relationships in tropical rainforest fern. Oecologia. 2007; 153: 225#8211;232. doi: 10.1007/s00442-007-0723-1PMID: 17415590 16. Westoby M, Reich PB,.Wright IJ.Understanding ecological variation across species: area-based vs mass-based expression of leaf traits. New Phytology. 2013; 199: 322#8211;323 doi: 10.1111/nph.12345 PMID:23692294 17. Wright IJ, Reich PB, Westoby M, Ackerly DD, Baruch Z, Bongers F, et al. The worldwide leaf economics spectrum. Nature. 2004; 428: 821#8211;827. doi: 10.1038/nature02403 PMID: 15103368

3. 毕业设计（论文）进程安排

2018.12.30-2019.1.25: 确定课题，查阅文献，提交开题报告。

2019.2.10-2019.4.20: 完成采集、处理； 完成碳同位素、C、N元素含量测定和叶片形态测定； 2019.4.21-2019.5.10: 完成对数据的统计处理和图表化分析； 2019.5.10-2017.5.25: 撰写毕业论文，准备论文答辩。