Abstract:
In order to explore the the “fertilizer island” effect in different spatial positions of two shrubs in the Gurbantunggut Desert,the dominant shrubs in the desert-Eremosparton songoricum and Calligonum mongolicum were used as research objects.Sampling points were set up by extending outward at 20(A),60(B),100(C),and 140 cm(D) with the shrub root as the center,each sampling point was sampled at three soil depths(0<h≤5 cm,5 cm<h≤10 cm,10 cm<h≤20 cm,and the soil nutrient content and enrichment at different spatial locations were analyzed respectively.The results indicated that:(1)Both E.songoricum and C.mongolicum had a “fertilizer island” effect,and there were significant differences in soil nutrient content among different species and spatial locations(P<0.05).The variation trend of the two plant soil nutrients in different spatial distributions was the same,that was,in the horizontal direction,they gradually decreased as the distance from the center of the shrub increased.Among them,the soil SOM,AK,and TN contents of E.songoricum at location D were decreased by an average of 58.16%,52.94%,and 68.18% compared to A,respectively.The content of SOM,AK,TN,and EC in the soil at location D were decreased by an average of 61.38%,13.33%,69.23%,and 21.81%,respectively,compared to location A.In the vertical direction,the content of SOM,AK,and TN in the soil of the two types of plants showed the highest nutrient content in the surface soil,and showed a decreasing trend with the increase of soil depth.The content of AK,pH,and N-NO
3- in the rhizosphere soil of C.mongolicum was significantly higher than that of E.songoricum(P<0.05).(2)The enrichment rates of SOM,AK,TN,and total phosphorus(TP) in the soil of the two shrubs showed consistent trends,that was,the enrichment rate of soil nutrients gradually decreased with the increase of soil depth,and the enrichment rate of soil nutrients gradually decreased with the increase of shrub center.(3)There was a significant correlation(P<0.05) between soil enrichment rates at different spatial locations and plant height and crown width.The plant height and crown width of E.songoricum and C.mongolicum showed a significant positive correlation with soil SOM,TN,N-NO
3- enrichment rates.In general,both plants showed a “fertilizer island effect”,with obvious spatial heterogeneity in different spatial distributions,different plants had different enrichment capacities for soil nutrients,and their “fertilizer island” effects were also different,with obvious species effects.