| Lichen is a kind of "bacteria-algae symbiosis" organism formed by long-term evolution,lichens are important groups of epiphytic organisms in the ecosystem and play an important role in the ecosystem and biodiversity.However,the species and community distribution of lichen are closely related to lithology and ecological factors of surface environment.The species and community distribution characteristics of arboreal lichens are also related to the species and distribution of the host.In this study,the epiphytic lichens on the rock surface of haikou shishan volcanic group world geopark and its surrounding areas and wenchang tongguling national nature reserve in the northeast of hainan were randomly collected to study the community composition and distribution of epiphytic lichens,and to compare the similarities and differences of epiphytic lichens on rocks of different textures(granite and basalt).At the same time,taking the tongguling area as an example,the similarities and differences of the composition of lichens in rock face and lichens attached to trees in the same area were comparedSampling method:In wenchang tongguling national nature reserve(16.43hm2),24 sampling points(17 points in the forest,were randomly selected from the tropical coastal forest.7 roadside sites),a total of 292 lichen samples were collected.geological park and its surrounding areas in haikou crater(85.95 hm2),randomly selected from 27 sample point(stone mountain near Zhen Town area four points,Stone mountain town of ridge nishimura four points,Shishan volcanic group national geopark has 10 sites,There are 6 sites in shicha village,shishan town,And the three tea village resorts near shicha village),a total of 113 lichen samples were collected.Twenty square sample points were selected from the tropical coastal forest(fixed large sample area)in the national nature reserve of tongguling,wenchang.A total of 217 samples of arboriceae lichens were collected,and then the species identification of lichens was carried out through the detection of fungal DNA barcoding technology.The research results show that:(1)in terms ofLithophytic lichen generated from rock surface,13 species of lichen generated from rock surface in tongguling reserve(granite)and 7 species of lichen generated from rock surface in crater area(basalt),all of which are relatively few.From the point of sampling,the relationship between species distribution and sampling points is complex.The species composition of epiphytic lichen in granite and epiphytic lichen in basalt is different and there is no same species.Among the 24 sampling points in tongguling,through detection,there are 4 sampling points with 4 species on the rock,3 sampling points are located in the forest,and only 1 is on the roadside.In addition,there are 13 species of lichens in forest rock face and 11 species of lichens in roadside rock face.Among the 27 sampling points in the crater,through detection,there are 3 sampling points with 2 species of clothing in the rock face.The sampling points are located in lingxi village,crater park and shicha village.In addition,there are 6 kinds of lichens on the rock surface in the crater park,5 kinds in shicha village,3 kinds in the area near shishan town,2 kinds in lingxi village,and 2 kinds in shicha resort.(2)in terms of species number of arboreal lichens,it was found that the species number of epiphytic lichens in tongguling forest was far more abundant than that in historical records.A total of 26 species of epiphytic lichens were detected,including 31 species of endophytic flungi,8 species belonging to basidiomycetes and 23 species belonging to ascomycetes,which enriched the records of epiphytic lichens in tongguling forest.From the distribution law of lichens,the vertical distribution characteristics of lichens are mostly shown as that the amount of lichens reaches the maximum within an altitude range.However,the difference in altitude between the 20 sample quadrates designed in this study is only 73m,almost at a height level.Almost the same elevation,lichens are randomly distributed.The results of the study on epiphytic lichens and trees further indicated that the main distribution height of epiphytic lichens in the range of sampling height below 2m was 0.6-1.4m,which was similar to the survey results in other areas.But lichens species and the relationship between the host and trees in the community is the important value,relative density,relative frequency,relative significant degree and individual number relationship is not big,Hydnocarpus hainanensis important value(9)on the trunk of the lichen,most species and important value of 4 Acronychia oligophlebia,important value of 8 Syzygium buxifolioideum and important value of 15 Psychotria rubra be collected in the trunk of lichen,preliminary judgment lichen on the host preference has nothing to do with the status of tree species in the community,to the distribution and the texture of the trunk and lichen,need further research,and the cause of the random distribution of lichen may be associated with a host of random distribution.(3)by comparing lichens on rock face with lichens attached to trees in tongguling area it is found that species richness of lichens on rock face is less than that of lichens attached to trees;And the species of lichen with rock as host are quite different from those with tree trunk as host.There were only two kinds of lichens with rocks and tree trunks as the substrate collected in the tongguling reserve,accounting for 15.40%of the total lichens in rock face,7.69%of the total lichens attached to trees,and 5.41%of the total lichens in tongguling.And these two kinds of lichens are not dominant species in rock face lichens and tree epiphytic lichens.The results show that lichen may be favorable to substrate.First,there is a significant difference in species composition between epiphytic lichens(13 species)in granite and epiphytic lichens(7 species)in basalt,and there is no common species,indicating that the host of epiphytic lichens has a preference for lithology.Second,lichen lithophores,also based on the epiphytic matrix of granite,accounted for 84.62%of lichen lithophores(11 species)collected by the roadside,which was 84.62%of lichen lithophores(13 species)collected in the forest.The distribution of lichen species was highly similar,further indicating that lichen lithophores were highly favorable to host lithology.Third,lichens also growing in the tongguling conservation area are more similar to lichens growing on rock face in the forest and lichens growing on rock face in the roadside.They are not more similar to lichens growing on trees in the forest a few meters away.Fourth:the number of species of arboreal lichens collected in the forest of tongguling reserve has nothing to do with the ecological status of the host in the community.The above four points jointly show that lichens are highly specific to hosts with different textures.Regardless of geographical location,they always tend to choose their preferred substrate for a particular type of lichen.Lichen on the same texture of matrix such as bark has a certain bias and specificity,but not strong;The distribution of lichen is related to the distribution of host. |
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