Analysis On Forest Landscape Pattern In Yongtai County Based On Fragstats

Landscape pattern is of great significance to the study of regional ecosystem structure and function optimization.With the rapid development of economy and society and the change of ecological environment,the study of forest landscape pattern has gradually become the focus of research.Yongtai County has vast mountain fields and rich forest resources.It is a key forest area in Fujian Province.Studying the forest landscape pattern in Yongtai County can provide scientific basis and reasonable suggestions for guiding the forest protection and utilization,for the scientific development and environmental management of forest resources.Therefore,Yongtai County was selected as the research area.This research used Landsat OLI remote sensing image which was taken on March 20,2018 as data source,used supervised classification to extract landscape elements,and used landscape ecology theories and methods to select landscape pattern index from landscape level and type level.The landscape pattern index was extracted and calculated by Fragstats 4.2 software.By analyzing the characteristics of landscape pattern in Yongtai County,the main conclusions were as follows:(1)Analysis of the landscape structure of Yongtai County showed that:the arbor forest land had an absolute advantage in the landscape pattern of the study area,with an area of 158991.21hm~2,accounting for71.32%of the total area.Arbor forest land was the main landscape of Yongtai County,which was concentrated and distributed in large areas in the whole county.The area of bamboo forest land was 15236.91hm~2,accounting for 6.83%of the total area,and the area of shrub forest land is16358.13hm~2,accounting for 7.34%of the total area.Both bamboo forest land and shrub forest land were scattered in various towns.In the non-forest landscape,the cultivated land area was 8774.46hm~2,accounting for 3.94%of the total area,the unused land area was15351.21hm~2,accounting for 6.89%,the building land area was6152.4hm~2,accounting for 2.76%,and the water area was 2067.66hm~2,accounts for 0.93%.The cultivated land and unused land were scattered in various towns and villages.The distribution area of construction land had a tendency to follow the landscape of the waters,and they were all distributed in stripes,from west to east.(2)Analysis of the landscape pattern characteristics of the study area from the landscape level:the total landscape area of Yongtai County was222931.98hm~2,the number of patches was 28305,and the patch density is12.6967.The landscape tended to be complex and heterogeneous.The landscape shape index was 83.0268 and the average shape index was1.269,both of which were relatively large,and the shape of the boundary of the patch was complicated.The aggregation degree index was 89.7301,the spread degree index was 61.3605,and the landscape separation index was 3.131.The aggregation degree index was higher,the degree of aggregation between landscape types was higher,and the degree of separation was lower,indicating that the connectivity between patches was better.The diversity index was 1.0702,and the patch richness index was 0.0031,which were relatively low,indicating that the diversity in the landscape was not high and there were obvious dominant tree species.(3)Analysis of landscape pattern characteristics of the study area from the type level:Among the forest landscape types in the study area,the border density of bamboo forest land,cultivated land,and unused land was large,which had a greater impact on the landscape of Yongtai County.The border density of construction land,arbor forest land and water was relatively small,which had little impact on the landscape of Yongtai County.Cultivated land had the highest degree of fragmentation and was greatly disturbed by humans.The largest patch index of in arbor forest land was largest,54.74,which was much larger than other patches,and it had a clear advantage in landscape patches in the study area.The shape index of bamboo patch land was the largest,105.9402,with the most irregular shape.The shape index of water was the smallest,25.8684,with the most regular shape.The split index of arbor forest land was3.1316,which was relatively small,indicating that the landscape of arbor forest land was simple,and it was concentrated in a large area in a county.The agglomeration index of arbor forest land was 94.7693,and the agglomeration degree was the best.The water area had the largest IJI value of 91.6965%,which indicated that the water area tended to be composed of large patches.The bamboo forest land and shrub land had smaller IJI values,which indicated that these two patches were composed of a single small patch.