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Ningxia University (2019)

Scale Effect Analysis of Spatial Variability of Seed Pests and Its Natural Enemy of Caragana in Desert Area,Ningxia

贺泽帅;

Titre : Scale Effect Analysis of Spatial Variability of Seed Pests and Its Natural Enemy of Caragana in Desert Area,Ningxia

Auteur : 贺泽帅;

Grade : Master’s Theses 2019

Université : Ningxia University

Résumé partiel
Caragana microphylla Lam.is a wind and sand-fixing plant that is not only an important wind-fixing plant in the northwestern desert,but also an important forage economic plant.Kytorrhinus immixtus,Etiella zinckenella and Bruchophagus neocaraganae are the main pests of Caragana seeds.Patterns and processes are important paradigms of ecology,processes produce patterns,and patterns act on processes.To correctly understand the relationship between the pattern and the process,it must be recognized that it depends on the characteristics of the scale,namely the scale effect.Scale effect is one of the hotspots in landscape ecology.In this paper,the Caragana forest land planted under the desert landscape was selected in Gaoshawo,Yanchi,Ningxia.The plot area was 200×200m.According to the sample of 10m×10m,(30 Caragana pods were randomly picked in each sample.3 times).Conduct indoor stripping and artificial feeding experiments,and count the number of pests,carnivorous natural enemies,pods,and soybeans in the range of 20×20 m to 200x200 m,and study with sampling scales.Changes,the number of pests,the damage rate,and the diversity of parasitic natural enemies varied,and explored the spatial scale effect of Caragana species pests and parasitic natural enemies.The main results and conclusions are as follows :(1)The spatial variation of the number of pests and the damage rate of Caragana has significant scale effectBy establishing 19 area gradients,using traditional statistical methods to study the pests and damage rate of Caragana under this area gradient,and fitting the functional relationship between the number and damage rate of Caragana species and the sampling scale.The results showed that the number and damage rate of Kytorrhinus immixtus decreased gradually with the sampling scale,and then increased gradually.At 10000 m2.the number and the damage rate were the lowest.The number and damage rate of Etiella zinckenella were not obvious with the change of sampling scale,and the quantitative distribution was more concentrated.

Mots clés : Caragana microphylla Lam.; seed pest; parasitic natural enemies; scale effect; spatial distribution pattern;

Présentation (CNKI)

Page publiée le 1er mai 2020