Abstract: Terrestrial plants have evolved an important functional trait spectrum, i.e., plant economics spectrum, which reflects the costbenefit tradeoff in resource acquisition. The plant economics spectrum was initially found in organs of mature plants. In recent years, mounting studies focus on the relationship between plant economics spectrum and litter decomposition. While there is a significant relationship between plant economics spectrum and litter decomposition, the strength of such correlation varies greatly across different studies. Such variations have been seldom addressed. Some trait spectra, e.g., hydraulics spectrum and chemical defense spectrum, are independent of plant economics spectrum, and are defined here as the non-economics spectrum. We reviewed the relationship between plant economics spectrum and litter decomposition. Furthermore, we proposed the view of non-economics spectrum from which we can understand the differences of different empirical studies in the strength of correlation between plant economics spectrum and litter decomposition rate. Then, we explored the potential ways by which non-economics spectra would affect litter decomposition, and consequently the relationship between plant economics spectrum and litter decomposition. In addition, we compared the difference between roots and leaves in terms of the relationships of abovementioned spectra with litter decomposition. Finally, several promising fields were proposed for future studies that aim to examine the role of non-economics spectra in accounting for the difference of the correlations between plant economics spectrum and litter decomposition among different studies.

Key words: nondestructive testing, nitrogen, BP neural network, Santalum album