Luyssaert Sebastiaan, Sulkava Mika, Raitio Hannu, Hollmén Jaakko
Parkano Research Station, Finnish Forest Research Institute, Kaironiementie 54, Parkano FIN-39700, Finland.
J Environ Monit. 2004 Feb;6(2):160-7. doi: 10.1039/b313372a. Epub 2004 Jan 20.
This paper introduces the use of nutrition profiles as a first step in the development of a concept that is suitable for evaluating forest nutrition on the basis of large-scale foliar surveys. Nutrition profiles of a tree or stand were defined as the nutrient status, which accounts for all element concentrations, contents and interactions between two or more elements. Therefore a nutrition profile overcomes the shortcomings associated with the commonly used concepts for evaluating forest nutrition. Nutrition profiles can be calculated by means of a neural network, i.e. a self-organizing map, and an agglomerative clustering algorithm with pruning. As an example, nutrition profiles were calculated to describe the temporal variation in the mineral composition of Scots pine and Norway spruce needles in Finland between 1987 and 2000. The temporal trends in the frequency distribution of the nutrition profiles of Scots pine indicated that, between 1987 and 2000, the N, S, P, K, Ca, Mg and Al decreased, whereas the needle mass (NM) increased or remained unchanged. As there were no temporal trends in the frequency distribution of the nutrition profiles of Norway spruce, the mineral composition of the needles of Norway spruce needles subsequently did not change. Interpretation of the (lack of) temporal trends was outside the scope of this example. However, nutrition profiles prove to be a new and better concept for the evaluation of the mineral composition of large-scale surveys only when a biological interpretation of the nutrition profiles can be provided.
本文介绍了营养概况的用途，这是开发一个适用于基于大规模叶片调查评估森林营养状况概念的第一步。一棵树或一片林分的营养概况被定义为营养状况，它涵盖了所有元素的浓度、含量以及两种或更多元素之间的相互作用。因此，营养概况克服了与常用的森林营养评估概念相关的缺点。营养概况可以通过神经网络（即自组织映射）和带有剪枝的凝聚聚类算法来计算。例如，计算了营养概况以描述1987年至2000年芬兰苏格兰松和挪威云杉针叶矿物质组成的时间变化。苏格兰松营养概况频率分布的时间趋势表明，在1987年至2000年期间，氮、硫、磷、钾、钙、镁和铝含量下降，而针叶质量（NM）增加或保持不变。由于挪威云杉营养概况的频率分布没有时间趋势，因此挪威云杉针叶的矿物质组成随后没有变化。对（缺乏）时间趋势的解释不在本示例范围内。然而，只有当能够对营养概况进行生物学解释时，营养概况才被证明是评估大规模调查矿物质组成的一个新的且更好的概念。
