Effect Of Gaps And Growth Substrates On Epixylic Bryophyte Community In A Minjiang Fir Forest

The bryophytes are an important component of the forest ecosystem and play an important ecological role in the forest’s hydrological cycle,nutrient cycling,and maintaining species diversity.The sensitivity of bryophytes to environmental changes is high.Therefore,forest forest window may have different influence on species composition,diversity,biomass and nutrient content of bryophyte community.At the same time,the updates of subalpine and alpine spruce forest and fir were mainly caused by forest window interference,and the forest window formed a significant influence on the light and water thermal dynamics of different growth matrix surfaces inside and outside the forest window.In the process of forest window forming,it also provides a good growth matrix for bryophytes.However,the research on the influence of forest window and matrix on epiphytic bryophytes has not been paid attention to,which can not satisfy the scientific demand of alpine forest ecological management.For understanding the mountain forest regeneration effect on bryophyte communities,this paper investigates the mountain forest ecosystems in different forest window location and different growth matrix pick bryophyte community composition,biomass,carbon,nitrogen,phosphorus and chemical metrology characteristic.The results show:The growth status and composition of bryophytes in different growth matrix were significantly different.Among them,the species diversity and community diversity of bryophytes in snag and large dead branches promoted the diversity of bryophytes.The highest reserve of bryophytes on the fallen log,which promoted the biomass of bryophyte community,and the dominant mosses were Neckera,Dicranum,Hylocomium.The substrate type for bryophytes of C,N and P nutrient content mostly had no significant effect,the N content of root pile on bryophytes,dry wood bryophytes P content was significantly lower than other substrate,this may be due to matrix nutrient status,the rainwater leaching,and the growth condition of bryophytes.The species diversity and community diversity of bryophyte community were significantly different with the decay class of the coarse woody debris.In early Ⅰ,Ⅱdecay classes,only the moss,curved tail bryophytes can grow a few bryophytes,to Ⅲ,Ⅳdecay classes obviously improve the community diversity,bryophytes biomass at this time,the largest go through Ⅳ,Ⅴ classes diversity and biomass of the decay process.Thick wood debris decomposition class for bryophyte nutrient content had no significant effect inⅠ,Ⅱ decay classes,with the decay process change,thick wood debris nutrient status of the change of volatile oil of bryophytes nutrient content have a significant impact,according to the different types of coarse woody debris and different decomposition class,results are obvious different effects.The effect of forest window on the diversity of bryophyte community on different substrate was obvious.In the gradient change of the forest window center to the forest,the Shannon-wiener diversity index showed a decreasing trend,and the Simpson index and Pielou index of gap edge were the highest among the three positions.The location of gap edge had a significant effect on the biomass of epiphytic bryophytes.The increase of light intensity and the tolerance of drought were reflected in different bryophytes: Entodon and Hylocomium were higher in drought tolerance,and had the best growth in the gap center.Such as Neckera,Dicranum,and Plagiomnium,had the largest growth in gap edge.With the lowest tolerances,such as Barbella,Leucodon,and Frullania,the biomass was the largest in the forest,not even in the gap center.Visible,forest gap updates and coarse woody debris decay process dramatically affects the bryophytes species diversity,biomass,community diversity and the content of nitrogen and phosphorus,affect the forest system nutrient cycle at the same time.Gap for overall plant community biomass and community diversity of alpine community moss have obvious role in promoting,but gap not affect bryophytes of C,N and P nutrient factors,decay class to pick bryophyte N and P nutrients have a significant impact.Alpine forest understory coarse woody debris,retained to increase forest ecosystem stability and promote the growth of bryophytes have positive effect,place coarse woody debris such as fallen log of the gap edge position,can obviously promote the growth of bryophyte diversity and community.For forests with relatively high density and low woody debris,artificial thinning can be selected to promote forest ecological stability.