Abstract:

Aims Wildfire had been one of the major forces that shaped the earth’s vegetation. However, few studies had documented how winter wildfire affected plant community structure. This study explores the response mechanism of subalpine grassland vegetation to winter wildfire.
Methods We chose subalpine areas of western Sichuan as a research site and selected 18 plots in subalpine grassland with and without winter wildfire. We analyzed community structure with species diversity analysis, TWINSPAN analysis and dry-weight-rank analysis.
Important findings Our study found that winter wildfire did not alter vegetation diversity, evenness, and species richness, but changed species composition. The quantity and biomass of annual grasses, perennial forbs and shrubs increased after winter wildfire. In addition, although the number of perennial forbs decreased, the biomass increased after winter wildfire. Moreover, the number and biomass of perennial grasses decreased, the biomass of graminoid species decreased and the biomass of forbs increased. Overall, winter wildfire decreased the competitive abilities of graminoid, such as Capillipedium parviflorum and Poa sp. Forbs, such as Leontopodium leontopodioides, Artemisia sacrorum and Anemone rivularis, had the advantage of competition for resources. Moreover, the edibility of grass was degraded following fire.

Key words: dry-weight-rank, forage quality, species diversity, subalpine grassland, TWINSPAN, plant community structure, winter wildfire