The objective of the study was to explore the difference of the plant growth, reactive oxygen content, malondialdehyde (MDA) content and antioxidant enzymes activity between the rolB-transgenic and non- transgenic of Pyrus betulifolia Bunge under drought stress , to further elaborate the effect of rolB on the drought resistance of the transgenic Pyrus betulifolia Bunge, and to provide a theoretical basis for cultivating high drought resistance of rootstock. The mild（T2，50%~55% soil relative moisture），moderate (T3, 40%-45% soil relative moisture) and severe (T4, 30%-35% soil relative moisture) drought stress treatments were conducted , with 70%-75% soil relative moisture treatment（T1）as the control . The result showed that the ration of root to stem，total chlorophyll content, carotenoids content and catalase（CAT） activity of  transgenic plant were significantly higher than non-transgenic Pyrus betulifolia Bunge before drought stress, and these were not significantly different in superoxide anion radical （O₂^-∙）content，hydrogen peroxide (H₂O₂) content, MDA content and superoxide dismutase (SOD), peroxidase（POD）activity. As compared to the control treatment (T1), the fresh weight, dry weight in transgenic plants did not change, but significantly decreased in non- transgenic plants under T2 treatment. The fresh weight, dry weight, ration of root to stem significantly decreased and O₂^-∙ content，H₂O₂ content and SOD,POD,CAT activity were improved of transgenic plants and non- transgenic plants under T3 and T4 treatment. However, the reactive oxygen content，MDA content were lower and SOD、POD、CAT activity were higher in transgenic plant than in non- transgenic plants under T3 and T4 treatment. In a word, the rolB gene enhanced the ration of root to stem, total chlorophyll content, carotenoids content and antioxidant enzymes activity, decreased the reactive oxygen and MDA content of transgenic Pyrus betulifolia Bunge, and improved drought resistance of the transgenic plant.

 In this study, the economic forest planting area in Taihang Mountain area was taken as the research object. Based on the hyperspectral remote sensing data of unmanned aerial vehicle, the hyperspectral characteristic database of different economic forest species was constructed, and the optimal identification model of economic forest species by hyperspectral remote sensing was obtained by using CART decision tree, maximum likelihood classifier (MLC), random forest (RF) and support vector machine (SVM). The results showed that: (1) The water vapor absorption bands of apple, apricot, persimmon, cherry and walnut were obviously different around the reflection peak of 550 nm, between 750-950 nm and around 960 nm; (2) The simple ratio index (SR), carotenoid reflex index 2 (CRI2), green band index (GRVI) and other 7 plants were more than 0.05, which were beneficial to the identification of economic forest species; (3) SVM was the best classification method based on spectral characteristic band, vegetation index and texture feature, which was better than MLC and RF algorithm. The overall accuracy (OA) was 95.11% and Kappa coefficient was 0.9158. To sum up, based on the combination of characteristic band, vegetation index and texture features, the identification method of support vector machine (SVM) classification was the best identification method for six tree species.

To study the improvement effect of litter on the cohesive yellow loam soil in southern China, different types of litter from four tree species, including hybrid Broussonetia papyrifera, were used as test materials. A soil sample from Xinji Town, Yizheng City was used as the test soil; The decomposition and nutrient release characteristics of litter were studied using the mesh bag decomposition method; The indoor cultivation method was used to study the effect of litter decomposition on soil physicochemical properties. The results showed that the highest organic matter content was found in the branches of Cinnamomum camphor (826. 8 mg / g), the highest total nitrogen (N) content was found in the branches of osmanthus (42. 54 mg / g), the highest total phosphorus（P）content was found in the branches of osmanthus (8. 04 mg / g), and the highest total potassium（K）content was found in the branches of osmanthus (93. 72 mg / g). Among different types of litter, the fastest decomposition rate is seen in the leaves of hybrid Broussonetia papyrifera (1a), while the slowest decomposition rate is seen in the roots of Cinnamomum camphora (2. 98 a). During the decomposition process, carbon（C）, N, P, and K all exhibit release states. Comparison between different tree species, the release rates of N and C differ significantly, while the differences in P and K are not significant. The correlation analysis shows that a higher N content in the same type of litter is beneficial for decomposition, while a higher C / N ratio is detrimental to litter decomposition. This study also showed that adding litter can reduce soil pH, while significantly increasing the content of organic matter, total N, alkali-hydrolyzable N, total P, available P, total K, and available K in the soil. Additionally, the addition of litter can significantly reduce soil bulk density, increase total soil porosity, and increase field water holding capacity. The decomposition rates of leaves, roots, and stems of hybrid broussonetia are the fastest among different tree species. Therefore, the litter of hybrid broussonetia can participate in the formation of soil aggregates faster and provide nutrients for the soil, making it suitable for application in the improvement of cohesive yellow loam soil in the south.