CAJ | 학술논문

可提取态碳水化合物（ EC）是植物光合作用的主要产物，能较好地反映植物的适应性和竞争力，目前对不同类群植物间的异同及其在适应与竞争机制方面的解释尚不明确。研究在亚热带地区马尾松林演替至常绿阔叶林中间阶段的次生混交林中选取17种常绿植物和13种落叶植物，于生长旺季和叶凋落期分别收集鲜叶和凋落叶，采用连续浸提7步分级法测定7类EC的含量，比较分析不同类型植物叶片EC的变化规律。结果表明，（1）常绿植物鲜叶游离态糖类的含量及百分比分别为52 mg／g和54％，均高于落叶植物的48．11 mg／g和49％，而水溶性半纤维素类相反（P＜0．05）；其它几种EC差异均不显著。（2）常绿植物凋落叶的游离态糖类、弱结合态糖类、强结合态糖类和水溶性半纤维素类占有机碳比例分别为10．82％、2．87％、2．70％和3．44％，均低于落叶植物的13．14％、3．95％、3．81％和4．51％；乔木凋落叶游离态糖类和弱结合态糖类占有机碳比例则为10．73％和2．78％，低于灌木的11．90％和3．40％及草藤本的11．98％和3．40％。（3）常绿植物鲜叶的游离态糖类和弱结合态糖类含量显著高于其凋落叶；而落叶植物鲜叶的游离态糖类和总EC含量则明显低于其凋落叶。推断与落叶植物竞争时，常绿植物可能通过提高鲜叶的游离态糖类含量，增强叶片碳源利用取得优势。
가제취태탄수화합물（ EC）시식물광합작용적주요산물，능교호지반영식물적괄응성화경쟁력，목전대불동류군식물간적이동급기재괄응여경쟁궤제방면적해석상불명학。연구재아열대지구마미송림연체지상록활협림중간계단적차생혼교림중선취17충상록식물화13충락협식물，우생장왕계화협조락기분별수집선협화조락협，채용련속침제7보분급법측정7류EC적함량，비교분석불동류형식물협편EC적변화규률。결과표명，（1）상록식물선협유리태당류적함량급백분비분별위52 mg／g화54％，균고우락협식물적48．11 mg／g화49％，이수용성반섬유소류상반（P＜0．05）；기타궤충EC차이균불현저。（2）상록식물조락협적유리태당류、약결합태당류、강결합태당류화수용성반섬유소류점유궤탄비례분별위10．82％、2．87％、2．70％화3．44％，균저우락협식물적13．14％、3．95％、3．81％화4．51％；교목조락협유리태당류화약결합태당류점유궤탄비례칙위10．73％화2．78％，저우관목적11．90％화3．40％급초등본적11．98％화3．40％。（3）상록식물선협적유리태당류화약결합태당류함량현저고우기조락협；이락협식물선협적유리태당류화총EC함량칙명현저우기조락협。추단여락협식물경쟁시，상록식물가능통과제고선협적유리태당류함량，증강협편탄원이용취득우세。
Extractable carbohydrates ( EC) are the main productions of plant photosynthesis and can indi?cate the adaption and competition ability of plant to environment changes. However, the differences in EC a?mong various plant groups, and the mechanism of plant adaption and competition are not much understood. Fresh leaves and foliar litters of 17 evergreens and 13 deciduous plants in the growing and non?growing seasons were collected,from a secondary mixed?forest,which was in the middle stage of succession from pinus massoni?ana forest to evergreen broad?leaved forest.The differences of the extractable carbohydrates measured by 7?step sequencing extraction method were compared among different plant functional groups. The results indicated that:(1) the content and percentage of free sugars and polysaccharides (FSP) were 52 mg/g and 54%,re?spectively in fresh leaves of evergreens,and higher than those of deciduous plants,which were 48.11 mg/g and 49% (P<0.05) respectively.In contrast,the water soluble hemicelluloses (WSH) showed an opposite trend with the FSP and other components of extractable carbohydrates were not different. ( 2 ) The percentages of FSP,weakly?bound polysaccharides and pectins (WPP),strongly?bound polysaccharides and pectins (SPP) and WSH to organic carbon were,respectively 10.82%,2.87%,2.70% and 3.44% in the foliar litters of ever?greens,and all lower than those of deciduous plants,which were 13.14%,3.95%,3.81% and 4.51% respec?tively.The proportions of FSP and WPP to organic carbon were 10.73% and 2.78% in the foliar litters of tree groups,lower than those of shrub groups,which were 11.90%,3.40% and herb groups with 11.98%,3.40%, respectively.(3) The contents of FSP and WPP in fresh leaves were significantly higher than those in foliar lit?ters of the evergreens,while the contents of FSP and the total extractable carbohydrates in fresh leaves were lower than those in foliar litters of the deciduous plants. Therefore, it might be deduced that the evergreens could obtain the advantage to use the strategy of increasing FSP content in the fresh leaves and improving the carbon use when competing with deciduous plants in subtropical forest succession.