黑木相思家系适地适树品种综合评价

[Objective]The highly intensive management of fir and eucalyptus plantations and the increment of successive generations have led to the problems of decreasing soil nutrient turnover capacity in plantations,and the decrease of soil fertility quality from generation to generation has become a major obstacle to sustainable management of plantations.In order to select Acacia nigra family with excellent adaptability and soil modification effect suitable for this soil condition in southern mountains.To reveal the relationship between the spatial differentiation pattern of soil nutrients of Acacia nigra and topographic changes.[Methods]In this paper,seven 15-year-old Acacia nigra lineages(M1～M7)created on fir harvesting sites in Fuching Lingshi Mountain Field were used as the research objects,and classical statistics,descriptive statistics,geostatistical methods and GIS techniques were used to analyze the variation patterns of soil physical and chemical properties and soil nutrients of different lineages through the study of forest growth characteristics,soil physical structure and nutrient characteristics on different slopes.The spatial distribution of soil nutrients was analyzed,and the seven Acacia nigra lines were evaluated by factor analysis and fuzzy evaluation method.[Results]The physical and chemical properties of the seven Acacia nigra lineages in different slopes mostly showed that the lower slope>middle slope>upper slope,and the lower slope was significantly higher than the other slopes;the soil structure and nutrient contents among the lineages showed that M7,M6 and M5 were better;the nutrient contents in the study area were generally distributed in blocks or strips,showing an increasing trend from northeast and northwest to south.[Conclusion]The comprehensive evaluation value was highest in the upper and lower slope of Acacia nigra family M7,and its growth had the best effect on the improvement of soil physical and chemical properties,and in the middle slope of Acacia nigra family M6.The results of the study were based on the concept of land-optimized layout of suitable species to screen out the suitable Acacia nigra lines for planting in southern mountainous areas,and provide theoretical technical support for the precise upgrading of forest stands.