Spatial Distribution Of Bryophytes In Mountain Regions Of Western Inner Mongolia

Bryophyte diversity plays a significant part in biodiversity.Due to considerable variations in average annual precipitation,western Inner Mongolia has a distinct horizontal zonal vegetation distribution ranging from typical grasslands to deserts with a variety of distinctive xerophytic bryophyte species,considerably enriching the bryophyte diversity in Inner Mongolia.In this paper,we analyzed the spatial distribution patterns of bryophytes in nine mountains across different zonal large-scale vegetation types in western Inner Mongolia and their relationships with climate factors by investigating the data of specimens and field collection.Therefore,we concluded the following results.(1)Western Inner Mongolia is home to 41 families,108 genera,and 297 species of bryophytes,including 14 families,17 genera,and 30 species of liverworts,as well as 27 families,91 genera,and 267 species of mosses.The dominant families(?20 species)include: Pottiaceae(82),Bryaceae(25),Hypnaceae(24),Grimmiaceae(20),and Brachytheciaceae(20).The dominant genera(?5 species)include: Didymodon(22),Bryum(19),Hypnum(13),and Campylium(5).The 297 species of bryophytes found in western Inner Mongolia's mountain regions can be classified into nine categories of floristic geographical composition,with the north temperate zone accounting for 47.48 percent of the total proportion.(2)With the change in mountain type,the overall trend in the number of bryophyte species in the seven botanical states was from east to west,and the number of bryophyte species was declining,following the same pattern as the number of vascular plant species in the seven states.(3)According to the analysis of the ?-diversity indexes of bryophytes in seven altitude ranges in the nine mountainous states,the largest ShannonWiener diversity index was found in altitude range of 1900-2100 m,with an index of 5.27;the lowest was found in altitude range of 1000-1300 m,with an index of 3.55;while there was no significant difference in the value of Pielous index in the seven altitude ranges.The Shannon-Wiener index was highest in Yinshan(4.76),lowest in Ejina(2.26),and the index of Pielous did not differ considerably in value throughout the seven plant states,according to an analysis of the-diversity index of bryophytes among the seven plant states.With rising altitude gradient,there was a general tendency of rising species followed by declining species,with the highest species richness identified in the altitude range of roughly 2000 m.(4)The similarity of families,genera and species of bryophytes in each altitude range was analyzed using Sorenson index,and the similarity of families and genera in each altitude range was generally high.The Sorenson index in D1(1000-1300m)and D3(1600-1900m)was 0.90 and 068,respectively,while the similarity index of the lowest genus was 0.33;the similarity coefficient of species varied considerably,with the highest being 0.65 and the lowest being0.144.According to the analysis of the similarity of families,genera and species of bryophyte in seven vascular plant states using the Sorenson index,it was found that among the seven vascular plant states,northern Yanshan and Yinshan had the highest similarity with a Sorenson index of 0.63,while northern Yanshan and Ejina had the lowest similarity with a Sorenson index of 0.08.The similarity of bryophyte families,genera,and species in nine mountain ranges in western Inner Mongolia was analyzed using the Sorenson index.Among the nine mountain ranges,Jiufeng Mountain and Wula Mountain had the highest family,genus,and species similarity indexes,with Sorenson indexes of 0.83,0.79,and 0.59,respectively;Jiufeng Mountain and Mazong Mountain had the lowest family,genus,and species similarity coefficients,with Sorenson indexes of 0.20,0.14,and 0.079,respectively.(5)The change pattern of ?c diversity species on the altitude gradient was determined using Cody index.According to the results,it was indicated that the largest Cody value(34.5)was in D1(1000?1300m)and D4(1900?2200m)among the seven altitude range,suggesting that the highest rate of change of bryophyte species was between these two altitude ranges;the smallest Cody index(7.5)was in D6(2500?2800m)and D7(2800?23200m),which implied that between these two altitude ranges,the rate of change of bryophyte species was the smallest.Similarly,the Wilson-Shmida index analysis revealed the same results.(6)According to the analysis of the relationship between data of the annual average temperature and precipitation and the number of bryophyte species in nine western mountains,it was revealed that the annual average precipitation and the number of bryophyte species followed the same trend,and that the number of bryophyte species decreased from west to east.According to the correlation analysis,the number of bryophyte species was highly significantly positively correlated with the average annual precipitation(P0.01);while the number of bryophyte species was negatively correlated with the average annual temperature,but the difference was not significant(P>0.05).Accordingly,precipitation was found to be the most dominant factor influencing the spatial distribution of bryophytes.