雌雄异株树种簇毛槭的生殖成功影响因子研究

[目的]以簇毛槭不同性别个体为研究对象检验生物因子及非生物因子对生殖成功的影响。[方法]在面积为21 hm²的大样地中定位监测183株簇毛槭的生殖生长及营养生长。利用线性回归分析检验生殖生长与营养生长间的权衡关系,利用路径分析模型量化生物因子及非生物因子对生殖成功的影响。[结果]雌性及雄性植株的生殖生长与营养生长间呈正向的线性关系(雌株:R²=0.40;p <0.05;雄株:R²=0.69;p <0.001)。坡度、有效花粉量对雌株开花量具有显著的负向影响(路径系数分别为-0.78和-0.41)。土壤水分、雌株胸径大小对雌株开花量具有显著的正向影响(路径系数分别为0.24和0.67)。叶面积指数显著地直接作用于有效花粉量(路径系数为0.58),因而叶面积指数表征的光照状况间接作用于雌株的开花量。雌株的结实量、坐果率、生殖营养比以及雄株的开花量、生殖营养比与解释性变量间没有显著的作用关系。[结论]簇毛槭的营养生长与生殖生长间存在着显著的权衡关系,而环境因子及花粉限制等因素对生殖成功的影响则很小。

Factors Affecting Reproductive Success in Dioecious Tree, Acer barbinerve

Objectives The influences of biotic and abiotic factors on the reproductive success were examined with individuals of different genders in Acer barbinerve. Methods The reproductive growth and vegetative growth of 183 trees of Acer barbinerve were observed in a 21 hm2 forest plot. The linear regression analysis was used to test the trade-offs between reproductive growth and vegetative growth. And path analysis model was used to quantify the influences of biotic and abiotic factors on the reproductive success. Results There is a positive linear relationship between the reproductive growth and vegetative growth for both female and male trees (female: R2 = 0.40; p < 0.05; male: R2 = 0.69; p < 0.001). Slope and effective pollen amount have a significant negative effect on the flowering amount of female trees (path coefficients are −0.78 and −0.41, respectively). Soil moisture and diameter at breast height of female trees have a significant positive effect on the flowering amount of female trees (path coefficients are 0.24 and 0.67, respectively). The leaf area index significantly directly affects the effective pollen amount (path coefficient is 0.58). Therefore, the light condition represented by the leaf area index indirectly affects the flowering amount of female trees. Fruit quantities, fruit setting rate and reproduction-nutrition ratio of females, and flower quantities and reproduction-nutrition ratio of males do not significantly relate with considering explanatory variables. Conclusions There is a significant trade-off between vegetative growth and reproductive growth. Environmental factors and pollen restriction have little effect on the reproductive success of Acer barbinerve.