2.2 Site setting and sampling
Typical SF, PB and CSF patches in wetland conservation areas were selected as sites. The dominant species in the SF plant community areSphagnum palustre , Carex nemostachys ,Oenanthe linearis , Neanotis hirsuta and Isachne globosa . The dominant species in the PB plant community arePolytrichum commune , Pteridium revolutum , Gaultheria hookeri , Smilax china , and Cyanotis vaga . The CSF was a pure artificial forest with an average density of 1283.33 trees/hm2, an average diameter at breast height of 10.44 cm, an average tree height of 8.68 m, and an average canopy density of 85%. There were sparse shrubs and herbs under the forest.
Three 1 m×1 m plots were randomly set near the centre of the SF and PB patches. In each plot, 0-10 cm soil was collected by using the random 3-point sampling method to form a mixed repeat soil sample. Three 20 m×30 m plots were set in CSF, one plot was set in the high and flat area with the terrain similar to that of SF, one plot was set in the low-lying area with the terrain similar to that of PB, and one plot was set in the transition zone between the two. Each plot was kept at least 10m away from the vegetation boundary between swamp forest and moss peatlands to avoid edge effects. The random 3-point sampling method was used to collect 0-10 cm soil to form a mixed repeat soil sample. Therefore, three repeated soil samples were collected for each of the three types of sites. Plant roots, litter and debris were removed immediately and stored under appropriate conditions. Each repeat soil sample was divided into 2 parts: one fresh soil sample was stored at 4°C for soil physicochemical property analysis, and the other was stored at -80°C for DNA analysis. Samples for the determination of soil bulk density and water content were collected simultaneously with the sampling.