中文摘要：

选取哈尔滨地区本地植物华北紫丁香和山槐，以及华北引进种紫穗槐为研究材料，于2003年秋季对3种植物叶片从夏末叶片盛期到秋末叶片脱水变干脱落全过程进行了连续测定。结果表明：1）2种仪器对于表征单位叶面积上叶绿素和N含量的有效性明显高于表征单位鲜质量上叶绿素和N含量。2）尽管PPW-3000和SPAD-502对于表征单位叶面积N含量和各种叶绿素含量具有一定的普适性（R^2=0．51—0．65），但不能有效表征不同植物的种间差异性。因此，使用2种便携式测定仪准确估计N和叶绿素含量需要首先确定每种植物的标准校正曲线。3）当表征同一种植物不同生长时期叶绿素和N含量变化时，2种仪器都适用于表征本地种华北紫丁香和山槐叶片衰老过程的变化（R^2〉0．82）；而对于外地引进种紫穗槐，叶片衰老脱水过程中叶绿素并未同时分解，表征效果欠佳（R^2〈0．66），甚至相关性不显著。可见，便携式仪器更适用于适应本地气候的正常衰老种的相关测定。4）2种仪器比较而言，PPW-3000对于表征叶片N含量变化，尤其是对于叶片衰老脱水过程叶绿素并未同时分解的叶片（如紫穗槐），效果较SPAD-502好；而对于叶片衰老过程中叶绿素同时降解的叶片（如华北紫丁香和山槐），2种仪器效果没有明显区别。

英文摘要：

For testing the practicability of using portable non-destructive meter of SPAD-502 and Agriexpert PPW-3000 for measuring the chlorophyll and leaf nitrogen changes during leaf autumn senescence, two local species of Syringa oblata, Maackia amurensis and one introduced species from north China, Amorpha fruticosa were measured from late summer （September） to late autumn （October） of 2003 by these SPAD-502, PPW-3000 and standard chemical method. The results showed that ： 1 ） Readings from the two instruments could represent chlorophyll a, b and a ＋ b and nitrogen content per unit leaf area, rather than per unit leaf fresh mass; 2） Although a general linear tendency between readings of PPW-3000 and SPAD-502 and real values of chlorophylls and nitrogen through 3 species was observed （ R^2 = 0.51 - 0.65 ）, readings from these 2 instruments alone could not effective identify the real difference among these 3 species. Therefore, a calibration line for each species between real values and the readings should be determined in the interspecies comparison; 3 ）When description of chlorophyll and nitrogen difference in different phases of leaf autumn senescence, two equipments could effectively descript the chlorophyll and nitrogen changes of two local species of S. oblata, M. amurensis （ R^2 〉 0.82）. However, they could not make effective description in the case of introduced species of A. fruticosa （ R^2〈 0.66）, and sometimes the correlation was not significant. The reason for this might be attributed to the fact that, comparing with local species, chlorophyll of introduced species didn＇t degrade simultaneously with leaf autumn senescence and dewatering. Thus, these two instruments are more suitable for measuring local species with simultaneous changes in leaf senescence and chlorophyll degradation; 4）Comparison on the practicability between PPW-3000 and SPAD-502 showed no obvious difference on the description of chlorophylls and nitrogen changes in the case of local species of S. oblata,