Study On The Structural Characteristics And Protection Benefits Of Farmland Shelter Forest In Alar Reclamation Areas

In this study,the farmland shelterbelt in the Alar reclamation area was taken as the research object,and the typical shelterbelt belt was selected according to the field conditions in the study area.Through field investigation and experimental analysis,a systematic study and evaluation of the Xinjiang populus and Populus euphratica two farmland shelterbelts' afforestation status and protection benefits,the main research results obtained are as follows:(1)Using the temporary standard land method,the vegetation composition and afforestation status of the sample plot were investigated in detail: the diameter structure distribution of the Xinjiang Populus and Populus euphratica is consistent with the standard normal distribution,and the two farmland shelterbelts are of the decline type;The understory shrubs consist of a single species,mainly including tamarix and wolfberry;the herbs are relatively abundant,and reeds are the dominant species in the understory,among which the common herbs are: lettuce,cleopatra,bitter bean and licorice.(2)By comprehensively analyzing the structural factors of forest belts and the characteristics of species diversity,the main structural factors that affect species diversity are: DBH,number of forest belt rows,plant row spacing and porosity;the greater the number of forest belt rows and plant row spacings,the richer the species;the sparse(Xinjiang populus)and diffusive(Populus euphratica)structure species are rich in species diversity;Xinjiang Populus shelter forest has more species diversity than populus euphratica forest.(3)The wind protection effect of farmland protection forests with different structure types is different,and the wind protection effect of sparse forest belts is the best;the main forest belt factors that affect the degree of transparency: breast diameter,crown width,belt height,number of rows,etc;the larger the breast diameter,the higher the forest belt,the wind protection effect of the protective forest the better;the windbreak effect is best when the number of forest belt rows is 2 rows(Populus euphratica)and 3~4 rows(Xinjiang populus);the windproof effect of the plant row spacing 2.5m×3m(Xinjiang populus)and3.5m×2m(Populus euphratica)is the best;The distance between the forest belts should be controlledbetween 150 m and 250m;the wind protection effect of different types of protective forests: Xinjiang populus is better than Populus euphratica.(4)The study of the microclimate and soil physical properties of different farmland shelterbelts shows that the shelterbelt's adjustment of air temperature and humidity(insulation and moisture retention)has an important impact on agricultural production,and Xinjiang populus is superior to Populus euphratica in regulating the field microclimate;There is a clear spatial difference in the distribution of the soil,and the water holding capacity of the Populus euphratica forest zone is significantly higher than that of the Xinjiang populus forest zone;farmland shelterbelts are a slow process for soil improvement.