摘要:以天然云冷杉（Picea jezoensis var.microsperma（Lindl.） W.C.Cheng&L.K.Fu and Abies nephrolepis（Trautv.） Maxim.）针阔混交林为研究对象，基于4块1 hm²固定样地林分调查数据和等距离网格布点取样的400个半分解层凋落物样品的养分测定数据，采用地统计学方法，分析凋落物磷浓度、归还量及利用效率的空间格局特征及其影响因素。结果表明：4块样地凋落物磷浓度均值为1.26 g/kg，归还量均值为24.57 kg/hm²，利用效率均值为841.74，均表现为中等强度变异，具有明显的空间异质性，且同一样地，变异程度呈现出磷归还量 > 磷利用效率 > 磷浓度。凋落物磷浓度、归还量（样地Ⅲ和IV结构比大于75%，其空间异质性主要由随机效应引起，不适合进行空间插值）和利用效率主要受结构性因素影响，具有较高的空间自相关性。同一样地磷利用效率的空间异质性较磷浓度及归还量低，各样地磷浓度、归还量和利用效率空间自相关范围分别为9.9-40.5 m、11.9-52.9 m和8.1-39.3 m。同一样地磷利用效率的分形维数高于磷浓度，空间格局较磷浓度复杂，磷浓度空间依赖性更强，具有更好的结构性。凋落物磷浓度、归还量（除样地Ⅲ和IV）和利用效率呈现条带状和斑块状梯度性分布，且磷浓度和利用效率的空间分布格局相似。凋落物磷浓度、归还量和利用效率受到郁闭度、物种数和植物多样性等多种因子的影响。



Abstract:In order to investigate the spatial heterogeneity of phosphorus (P) in the litter of natural Picea jezoensis var. microsperma (Lindl.) W.C.Cheng & L.K.Fu and Abies nephrolepis (Trautv.) Maxim. mixed forest and associated factors, four 1 hm² permanent plots were established for litter collection and surveyed for stand structure in northeastern China. A total of 400 litter samples from the semi-decomposed layer were collected using an equidistant grid point sampling method. The spatial variation in litter P concentration, return, and use efficiency were analyzed using geostatistics. The results showed that the average litter P concentration was 1.26 g/kg, the average P return was 24.57 kg/hm², and the average use efficiency was 841.74. The variation in P concentration, return, and use efficiency in the four plots was moderate, and the degree of variation showed that P return > P use efficiency > P concentration in an individual plot. Litter P concentration, return (the nugget-to-sill values in plots Ⅲ and IV were >75%, indicating that their spatial heterogeneity was mainly caused by random effects and they were not suitable for interpolation), and use efficiency showed high spatial autocorrelation, primarily resulting from structural factors. The spatial heterogeneity of P use efficiency was lower than that of P concentration and return, and the spatial autocorrelation ranges of P concentration, return, and use efficiency in the plots were 9.9-40.5 m, 11.9-52.9 m, and 8.1-39.3 m, respectively. Within plots, the fractal dimension of P use efficiency was higher than that of P concentration, with a more complex spatial pattern, while P concentration showed stronger spatial dependence with better spatial structure. Litter P concentration, return (except plots Ⅲ and IV), and use efficiency in the four plots showed strip and patch gradient distribution, and the spatial variation of P concentration was similar to that of P use efficiency. Litter P concentration, return, and use efficiency were influenced by canopy density, species, plant diversity, and other factors.





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