**1.Mass alteration**

Wood mass loss is commonly accompanied by most fungal decay due to that fungi need nutrients as they grow through the wood by utilizing the various components of the wood cell wall. Thereby, most wood decay fungi can utilize the various chemical components of the wood substrate in the cell wall as they colonize and grow through the wood, leading to the reduction of the overall wood mass [27]. Wood mass losses can achieve 70% through brown rot, even exceed 95% after white rot and about 5–60% by soft rot. Mass loss will be generally expressed at the different trend of change due to the various decay conditions, which depends on the diverse wood species including the types of decay fungi as well as the different periods during wood decay.

Mass losses of some wood species in different periods with both brown rot fungi and white rot fungi are presented in **Figure 1** (derived from the research of previous research [28] and authors' results [29]). As portrayed in **Figure 1**, the mass loss of wood clearly increased as the decay time prolongs. Besides, regarding softwood, brown rot fungi were stronger than white rot fungi. In contrast, in hardwood samples, the deconstruction capacity of white rot fungi to hardwood was more aggressive and vigorous than that of brown rot fungi, and this could be that the lignin types of hardwood mainly included guaiacyl lignin and syringyl lignin, and hardwood lignin contained more methoxyl groups, which was more easily decomposed [14, 30]*.* Furthermore, it was worth mentioning that, in hardwood group, *Hevea brasiliensis* showed more resistance against white rot fungi than *Populus yunnanensis* and *Liquidambar styraciflua*, which may be due to the density of *H. brasiliensis* higher than that of *P. yunnanensis* and *L. styraciflua*, attributing to the significant effect of density on wood properties (**Table 1**).
