贵州省喀斯特地区4种典型人工林叶片化学计量特征

为评价贵州省人工林生境养分供应状况及养分获取效率，以贵州省喀斯特地区4种典型人工林:华山松Pinus armandii林，杉木Cunninghamia lanceolata林，马尾松Pinus massoniana林和柏木Cupressus funebris林为研究对象，分析了以上4种人工林叶片生态化学计量学特征。结果显示:华山松、杉木、马尾松和柏木等4种典型人工林叶片碳（C）质量分数较高，氮（N）和磷（P）质量分数较低；各林型之间叶片碳质量分数变异较小，氮、磷质量分数以及碳氮比（C:N），氮磷比（N:P），碳磷比（C:P）变异较大。4种典型人工林各林型之间叶片生态计量学指标大部分差异不显著（P>0.05）。4种典型人工林叶片碳氮比（C:N）和碳磷比（C:P）较大，表明它们从生境中获取养分的效率较高，而氮磷比（N:P）则揭示了杉木林和华山松林的生长受氮限制、柏木林受磷限制，马尾松林受氮和磷的共同限制。表2参25

Leaf C,N, and P stoichiometry for four typical artificial forests in the karst region of Guizhou Province

To evaluate soil nutrient supply and nutrient use efficiency of artificial forests in the karst region of Guizhou Province, four typical artificial forests, namely Pinus armandii, Cunninghamia lanceolata, Cupressus funebris, and Pinus massoniana, were selected. Contents of C, N, and P in fresh leaves of the four selected artificial forests were analyzed using a variance analysis (ANOVA). Results showed that C content in leaves across the four artificial forests was relatively high, ranging from 555.453 to 628.125 mg·g-1. However, N content and P content of leaves were much lower than Toona sinensis and Zenia insignis in Guangxi Province. Furthermore, the variation coefficients of C content were very small variation in the four artificial forest types; whereas, variation coefficients of N and P contents, as well as the ratios of C:N, N:P, and C:P in leaves had greater range of variation. Statistical analysis revealed that most indexes of leaf ecological stoichiometric characteristics were not significantly correlated for each of the four artificial forests(P>0.05). Compared to published data of natural karst forests, the higher C:N and C:P ratios in this study meant that the four selected artificial forests had higher effective nutrient utilization. Also, N:P ratios of leaves in the four artificial forests revealed that 1) growth of Pinus armandii and Cupressus funebris was N-limiting, 2) growth of P. massoniana was P-limiting, and 3) growth of Cunninghamia lanceolata was both N- and P-limiting. Therefore, understanding leaf C, N, and P stoichiometry gleaned from this study would be crucial for developing reliable strategies and management of artificial forests in the karst region of Guizhou Province.Ch, 2 tab. 25 ref.]