| Clarifying the ecological effects of changes in landscape patterns on the occurrence of pests associated with Artemisia ordosica is fundamental to the ecological regulation of regional boring pests that in A.ordosica.This research paper employs the principles of traditional ecology and landscape ecology to investigate this topic.A total of 12 patches with significant differences in habitat heterogeneity were selected as the study area,based on the occurrence sites of two boring pests,Holcocerus artemisiae and Sphenoptera canescens.The degree of mixing between A.ordosica and other sandy plants,as well as the quality of A.ordosica patches(including soil desertification and vegetation characteristics),were analyzed using ANOVA to determine their effects on the occurrence of the two pests,and a generalized linear model was employed to examine the response of the two boring pests to changes in landscape patterns.The "Akaike information criterion" was employed to screen the optimal spatial scale model,and model predictions were generated for the larval population density and the rate of insect-bearing plants for the two pests.The main findings and conclusions are summarized as follows:(1)At the patch level,the occurrence of the two boring pests varied significantly(P<0.05)based on patch type and patch quality.The average rate of insect-bearing plants in patches of A.ordosica was significantly higher(69.3%)in moderately desertified(40.6%on average)and rehabilitated patches(66.2%on average)compared to lightly desertified patches(40.6%on average).The population densities of H.artemisiae in moderately desertified,lightly desertified,and rehabilitated patches were 0.37,0.17,and 0.16 per plant,respectively.The population densities of S.canescens in these patches were 0.48 per plant,0.25 per plant,and 0.59 per plant,respectively,and they were significantly more influenced by the degree of sanding compared to those of A.ordosica.The rate of insect-bearing plants was higher in patches of A.ordosica(71.9%on average)compared to patches of A.ordosica tree mix(65.0%on average)and A.ordosica shrub mix(30.8%on average).The population densities of H.artemisiae in patches of A.ordosica,A.ordosica tree mix,and A.ordosica shrub mix were 0.36 per plant,0.53 per plant,and 0.13 per plant,respectively.The population densities of S.canescens were 2.53,0.89,and 0.31 per plant,respectively.The total vegetation cover,plant diversity in the herbaceous layer,and population density of A.ordosica were significantly and negatively correlated with the rate of A.ordosica with insects(P<0.05).Therefore,increasing plant diversity in the habitat and reducing sandiness can to some extent decrease the occurrence of boring pests of A.ordosica.(2)At the landscape level,the findings from the optimal model based on different spatial scales(0.5 km,1.0 km,1.5 km,2.0 km)of landscape components revealed distinct patterns.The optimal scale for the spatial response ofH.artemisiae was determined to be 1.0 km.The landscape diversity index exhibited a significant positive correlation with the larval population density of H.artemisiae at spatial scales of 1.0 km,1.5 km,and 2.0 km(P<0.01).Additionally,the anthropogenic disturbance factor,represented by the proportion of building land area,demonstrated a negative correlation with the larval population density of H.artemisiae at spatial scales of 0.5 km and 2.0 km(P<0.05).In contrast,no optimal response scale to landscape pattern changes at different spatial scales was observed for S.canescens.Thus,the spatial response scales of boring pests to landscape composition differ due to their distinct biological characteristics.Moreover,the impact of landscape heterogeneity on H.artemisiae is more pronounced than that on S.canescens.Human interference can,to some extent,mitigate the occurrence of H.artemisiae populations. |
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