Study On The Forest Landscape Pattern Of Qinlian Forest Farm In Guangxi

In this paper,the forest resources survey data and forest facies maps of the state-owned Qinlian Forest Farm in Guangxi in 2004,2009 and 2013 were used as research materials.Firstly,using the combination of landscape pattern analysis software and ArcGIS technology,the whole forest landscape pattern was quantitatively analyzed from three aspects:the overall characteristics of forest landscape pattern,the heterogeneity of landscape patches and the heterogeneity of landscape level.Then,using qualitative analysis method,six factors such as policy,market,harvesting and topography,climate and disaster are selected to analyze the impact of each factor on the distribution of forest landscape types.Finally,using principal component analysis method,seven specific factors such as investment cost,financial revenue,afforestation area,harvesting area and elevation,wind disaster and fire are analyzed and modeled.A comprehensive index model of forest landscape change with seven factors was developed,and the main driving factors affecting the change of forest landscape pattern in the state-owned Qinlian Forest Farm in Guangxi were obtained.The results of this study are as follows:(1)Nine forest landscape types were used to study the forest landscape pattern of forest farms.The forest landscape types were forest land,sparse forest land,shrub forest land,unfinished forest land,non-standing forest land,nursery land,suitable forest land,auxiliary production land and non-forest land.(2)The forest landscape area of Qinlian State-owned Forest Farm in Guangxi changed in three periods.From 2004 to 2009,the forest landscape area decreased from 60101.9 hm2 to 59983.3 hm2,and decreased to 118.6 hm2.From 2009 to 2013,the forest landscape area increased from 59983.3 hm2 to 6164.5 hm2,and increased to 181.2 hm2.Generally speaking,the area of forest landscape increased from 2004 to 2009,with an increase of 1 062.6 hm2.The area of forest land increased by 1 872.7 hm2 and the area of non-forest land decreased by 691.5 hm2.(3)According to the proportion of forest landscape types in the three periods of Qinlian Forest Farm in Guangxi,the dominant landscape types in 2004,2009 and 2013 were all woodlands,accounting for 64.70%,69.07%and 73.74%respectively;the relatively small proportion in 2004,2009 and 2013 were nursery land,sparse woodland,unfinished woodland and non-woodland,accounting for less than 1%of the total.Taken together,the dominant landscape types of the three phases have not changed significantly,and other landscape types are only supplementary,scattered and mosaic in the landscape,forming a patch-corridor-patch-like landscape pattern pattern.(4)From the level of forest landscape patches in Qinlian Forest Farm of Guangxi,the number of forest landscape patches increased from 28568 to 28832 and then to 33333 in 2004,2009 and 2013.The average area ratio of landscape patches decreased from 2.10 to 2.08,then to 1.83,and the fragmentation index of landscape patches increased from 0.4800 to 1.83.The shape index of landscape patches increased from 19.19 to 23.92 and then to 25.12.Generally speaking,landscape patches tend to be fragmented and complicated.(5)From the view of forest landscape level of Qinlian Forest Farm in Guangxi,Shannon diversity index and Shannon evenness index of forest landscape declined gradually in 2004,2009 and 2013,and landscape dominance index increased gradually.Shannon diversity index decreased from 1.1881 to 1.0854,then to 0.9044;Shannon evenness index decreased from 0.1147 to 0.1057,and then to 0.1057.The landscape dominance index increased from 9.1711 to 9.1838 and then to 9.5099.Generally speaking,the whole landscape is developing unevenly,and the proportion of each landscape type is quite different.(6)By using qualitative analysis to analyze the driving forces of forest landscape pattern change in the state-owned Qinlian Forest Farm in Guangxi,the main influencing factors are policy factors and market factors,while climate factors have little effect.Secondly,through principal component analysis,it is concluded that the changes of investment cost and financial revenue are the primary factors affecting forest landscape,while wind disaster and elevation are the secondary factors affecting forest landscape.The driving force comprehensive index model of forest landscape distribution was obtained by principal component analysis:F=0.725*F1+0.275*F2(F1:human factor,F2:natural factor)Through the analysis,the driving force comprehensive index is proportional to the distribution of dominant forest landscape types in Qinlian Forest Farm.The larger the comprehensive index,the more complex the landscape distribution and the higher the fragmentation degree.Generally speaking,the main driving force of forest landscape pattern change in Qinlian Forest Farm is human factors,followed by natural factors.