| 摘要: |
| 【目的】了解亚热带地区云南松(Pinus yunnanensis)幼龄林和中龄林针叶非结构性碳水化合物（NSC）及碳（C）、氮（N）、磷（P）含量的四季动态平衡变化，以促进对不同林龄植物养分利用策略的理解。【方法】通过比较云南宜良地区云南松幼龄林（15年）和中龄林（25年）针叶NSC（可溶性糖和淀粉）含量和C、N、P含量的季节变化特征，探讨云南松幼龄林和中龄林针叶NSC含量和C、N、P化学计量特征的差异原因,以及它们之间的相关性。【结果】① 随四季变化，云南松幼龄林和中龄林针叶可溶性糖、淀粉和NSC含量表现出不同程度的降低，可溶性糖/淀粉值先升后降，在8月最高（幼龄林为1.41，中龄林为1.85），1月最低（幼龄林为0.93，中龄林为0.88）。② 云南松幼龄林和中龄林针叶C含量8月最低（幼龄林为389.77 g/kg，中龄林为386.10 g/kg），N含量和P含量表现为先下降后上升，且在8月份最低，1月份最高。云南松幼龄林和中龄林针叶C/N、C/P值在8月最高（幼龄林为900.25和2 624.83，中龄林为1 143.65和2 200.80），而N/P值在5月最高（幼龄林为3.38，幼龄林为2.46）。③ 云南松2个林龄林木针叶C、N、P含量与NSC含量之间呈极显著正相关；而C/N、C/P与NSC含量之间表现为极显著负相关关系，N/P与NSC含量间相关性不显著。【结论】云南松幼龄林和中龄林均通过调整其针叶NSC和C、N、P的分配应对四季气候的变化，且2个林龄间分配方式相似。在生长旺盛期（8月），云南松幼龄林和中龄林均通过增加针叶可溶性糖与淀粉之间的转化，来增强云南松针叶的生理活动；但云南松幼龄林和中龄林针叶C、N、P含量变化在生长旺盛期表现出不同的变化规律。 |
| 关键词: 云南松 林龄 森林培育 非结构性碳水化合物 碳氮磷化学计量特征 |
| DOI： |
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| 基金项目:国家自然科学基金项目(31960306) |
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| Characterization of non-structural carbohydrates and carbon,nitrogen and phosphorus stoichiometry of needles in young and middle-aged Pinus yunnanensis forests |
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LIU Yuanxi,WU Junwen,ZHAO Zhijuan,et al
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| Abstract: |
| 【Objective】This study investigated seasonal dynamic changes in contents of non-structural carbohydrates (NSC),carbon (C),nitrogen (N) and phosphorus (P) of coniferous leaves in young and middle-aged Pinus yunnanensis forests in the subtropics to improve the understanding of nutrient utilization strategies of plants in different forest ages.【Method】Seasonal changes in NSC (soluble sugars and starch),C,N and P contents in needle leaves of Pinus yunnanensis between young (15 year-old) and middle-aged (25 year-old) forests in Yiliang,Yunnan were studied,the causes were investigated,and their relationships were analyzed.【Result】① The needle soluble sugars,starch and NSC contents of young and middle-aged Pinus yunnanensis forests decreased differently as season changes,and the soluble sugar/starch ratio increased firstly and then decreased with the highest in August (1.41 in young and 1.85 in middle-aged forests) and the lowest in January (0.93 and 0.88,respectively).② The C contents of needles in young and middle-aged stands of Pinus yunnanensis were the lowest in August (389.77 and 386.10 g/kg),and N and P contents decreased before increasing with the lowest in August and the highest in January.Needle C/N and C/P ratios in young and middle-aged stands of Pinus yunnanensis were the highest in August (900.25 and 2 624.83 in young stands and 1 143.65 and 2 200.80 in middle-aged stands),while needle N/P ratio was the highest in May (3.38 and 2.46 in young and middle-aged stands).③ There were significantly positive correlations between C, N and P contents of needles and NSC contents in young and middle-aged Pinus yunnanensis forests,C/N and C/P ratios had significantly negative correlation with NSC contents,while N/P ratio had insignificant correlation with NSC contents.【Conclusion】Both young and middle-aged stands of Pinus yunnanensis responded to seasonal climatic changes by adjusting their needle NSC,C,N and P allocation,and this allocation was similar between the two stands.During the peak growth period (August),both forests enhanced physiological activities of Pinus yunnanensis needles by increasing soluble sugars and starch conversion.The changes in needle C,N and P contents in young and middle-aged Pinus yunnanensis forests showed different patterns during the peak growth period. |
| Key words: Pinus yunnanensis forest age forestry silviculture non-structural carbohydrates carbon,nitrogen and phosphorus stoichiometry |
