Objective: Quantitative analyses of the relative effects of habitat heterogeneity and dispersal limitation on species diversity of subtropical evergreen broad-leaved forest community in south China were conducted to provide a theoretical basis for further revealing the mechanism of diversity maintenance in the southern subtropical evergreen broad-leaved forest community in Dinghu Mountain. Method: Based on the information on spatial distribution of 71 333 plants and 195 species in a 20 hm² plot of the southern subtropical evergreen broad-leaved forest community of Dinghu Mountain, we systematically compared the mechanism of species diversity maintenance with an accurate and reliable spatial statistical simulation method. Four different models including homogeneous Poisson model, heterogeneous Poisson model, homogeneous Thomas model and heterogeneous Thomas model were used to test spatial processes of habitat association and seed dispersal, allowing us to evaluate the potential contribution of habitat heterogeneity and dispersal limitation to the formation of spatial patterns of tree species, and the combined effects on species-area relation (SAR) of species diversity pattern. Result: Most populations displayed a clustered spatial distribution, and both the habitat heterogeneity from the habitat diversity hypothesis and the dispersal limitation from the community neutral theory produced significant effects on species diversity pattern. The simulation of spatial point pattern model revealed that the combined effects of habitat heterogeneity and dispersal limitation provided a better explanation of the SAR compared with their separate effects. At the same time, the simulation of distribution process of species with Cox process showed that the proportion of species affected jointly by habitat heterogeneity and dispersal limitation was higher than that affected separately by them in the same community. The effect of habitat heterogeneity (31.12%) was higher than that of dispersal limitation (25.13%), however, 43.75% of the detected species were significantly affected by both processes. Conclusion: Both habitat heterogeneity and dispersal limitation were the main driving forces to maintain species diversity in the study area, none of them can be ignored. In terms of separate effects, the habitat heterogeneity was stronger than the dispersal limitation in south subtropical forest community in Dinghu Mountain. In order to further reveal the mechanism of diversity maintenance, further specific studies are needed on the mechanism and contribution of different species groups at different scales.

Objective: In order to reveal the influence of changes of forest types on greenhouse gases emission from soils, the fluxes of greenhouse gases, the annual contribution rate and the patterns of warming potential were investigated for 8 temperate forest types in the northeast during the non-growing season. Method: With the static chamber-gas chromatography method, CH₄, CO₂, and N₂O fluxes were measured along with the environmental factors (snow cover thickness, 5 cm deep soil temperature T₅, 0-40 cm soil water content, organic carbon, available nitrogen, pH) from two 51-year-old plantation (Korean pine plantation HR and larch plantation LR), 5 natural secondary forests with 61 to 67 years old hardwood forest YK, Betula platyphylla forest BH, Populous davidiana forest SY, mixed deciduous forest ZM, Mongolian oak forest MGL, and 150-year-old primary Korean pine and broad-leaved mixed forest YS, One-way variance and Duncan method were used for variance analysis and multiple comparison (α=0.05). Multiple stepwise regression was used to find the main factors affecting the greenhouse gas flux from all environmental factors. Result: The CO₂ fluxes were 15.97-57.86 mg·m^-2h^-1among the 8 temperate forest types during the non-growing season, and those of the 2 plantations and the 4 secondary forests (except for MGL) were significantly higher than those of YS respectively by 107.5%-147.1% and 135.3%-262.3% (P < 0.05); The CH₄ absorption values were -69.74--9.13 μg·m^-2h^-1 among the 8 temperate forest types during the non-growing season, and the values of the 3 secondary forests (YK, SY, ZM) were significantly higher than that of YS by 152.8%-174.6% (P < 0.05), while those of the 2 plantations were significantly lower than that of the YS by 52.0%-64.1% (P > 0.05); The N₂O fluxes were 7.68-40.55 μg·m^-2h^-1 among the 8 temperate forest types during the non-growing season, and the 2 plantations and 3 secondary forests (YK, SY, ZM) were significantly higher than YS by 114.2%-286.6% and 116.3%-192.0% (P < 0.05) respectively; During the non-growing season, soil CO₂ emissions from YS were mainly controlled by T₅, 0-40 cm soil water content, pH and nitrate nitrogen, while that from the plantations were mainly influenced by T_5, and snow cover thickness, and the CO₂ emissions from the secondary forests were mainly controlled by T₅ and 0-40 cm soil ammonium nitrogen (YK and MGL). CH₄ fluxes from YS were impacted only by T₅, from the 2 plantations by snow cover thickness, and from the secondary forests by T₅ and 0-40 cm soil ammonium nitrogen. N₂O fluxes from YS was mainly controlled only by snow cover thickness, while those from the plantations and the secondary forests were generally controlled by 0-40 cm soil ammonium nitrogen, moisture content and snow cover thickness. Compared with YS, the plantations and the natural secondary forests reduced the annual contribution rate of soil CH₄ uptake (12.3%-30.2%) by 2.8%-10.0% (except SY) during the non-growing season, and made the annual contribution rates of CO₂ and N₂O emissions (4.8%-12.5% and 7.0%-63.6%) with an increase by 3.1%-7.7% or 3.0%-56.6%, respectively. The greenhouse gas warming potential (71.16-250.64 g CO₂·m^-2) of the 2 plantations and the 5 natural secondary forests showed a significant increase of 130%-190% and 120%-250% (P < 0.05) during the non-growing season, compared with YS. Conclusion: Therefore, the effects of early human disturbance on greenhouse gases fluxes during the non-growing season have not been completely eliminated even after 51-67 years of restoration of the plantations and natural secondary forests since the clear-cut of the primary temperate forests of Korean Pine. The CO₂ and N₂O fluxes of plantations and secondary forests were significantly higher than that of YS. The CH₄ flux of secondary forests was significantly increased, while that of plantations was significantly decreased.

Objective: This study is aimed to investigate the characteristics of changes of soil nutrients and stoichiometrict ratio during the expansion of moso bamboo (Phyllostachys edulis) forest, in order to provide a theoretical basis for the regulation of expansion of moso bamboo forest. Method: Three 10 m×50 m sample transects each with 3 sample plots were set up along the extension direction of moso bamboo forest in Yongan Long-Term Ecological Observation Station for Bamboo Forest in Fujian Province. The characteristics of soil nutrients and stoichiometric ratios at different expansion stages(along the expansion direction in order: early expansion, middle expansion, and late expansion) were analyzed, in order to reveal the patterns of impacts on soil nutrients by the expansion of moso bamboo. Result: During the expansion of moso bamboo to abandoned land, the variation coefficients of soil nutrients and stoichiometric ratios in 0-30 cm soil layer was as follows: late expansion stage (13.8%-51.3%) > middle expansion stage (8.3%-31.8%) > early expansion stage (4.3%-29.8%). The variation range of variation coefficient of C and N contents (26.7%-43.8%) was larger than the contents of P and K (4.3%-24.1%). With the expansion of moso bamboo to abandoned land, the contents of C and N increased significantly and P decreased significantly. In 0-20 cm soil layer, the contents of C and N of the later stage of expansion was significantly higher than that of the earlier and middle stages of expansion (P < 0.05). In 20-30 cm soil layer, there was no significant difference for the contents of C and N among different expansion stages (P> 0.05);but the content of P decreased significantly with the expansion of Phyllostachys pubescens (P < 0.05). In 0-30 cm soil layer, C:N was relatively stable, and there was no significant difference between different expansion stages. C:P and N:P of the later stage of expansion were significantly larger than that of the earlier stage, but there was no significant difference between the earlier stage and the middle stage of expansion (P> 0.05). In 0-30 cm soil layer, there was a significant positive correlation between C and N (P < 0.01); C and N were negatively correlated with K(P < 0.01), but no significant correlation with P. C:N was significantly correlated with C:P, but not with N:P. Conclusion: With the expansion of moso bamboo, the contents of soil C and N in 0-20 cm soil layer increased significantly(P < 0.05), while the content of soil P decreased significantly(P < 0.05). In 0-30 cm soil layer, the content of K did not change significantly at different expansion stages. C:P and N:P at the late stage of expansion were significantly higher than those at the early stage, but N:P was still lower than the average levels of China and the world, and the contents of N and P could not meet the demand of moso bamboo forests. Soil nutrient content of moso bamboo forest increased at the later stage of expansion, but its effectiveness decreased, which was not conducive to the healthy and stable development of moso bamboo forest. In order to maintain the healthy growth of moso bamboo forests, it is necessary to regulate and supplement N and P elements in time.

With the technique of in situ continuous monitoring of chlorophyll fluorescence, the energy distribution of photosystem Ⅱ in Salix psammophila and its response to environmental factors were explored in the semi-arid area of Mu Us sandy land. The dynamic effects of environmental factors on energy distribution of the photosystem Ⅱ and their photosynthetic physiological adaptation strategies were revealed in the daily and seasonal scales, in order to provide theoretical guidance for vegetation restoration management and species selection in the study area.Method: Chlorophyll fluorescence was continuously measured in situ and fluorescence parameters were calculated using Kramer methods of light energy allocation. Result: At the diurnal scale, photochemical efficiency φ_PSⅡ) and regulated heat dissipation φ_NPQ) were directly related to photosynthetically active radiation (PAR), and also influenced by air temperature (T_a), relative humidity (RH) and vapor pressure deficit (VPD).The non-regulate heat dissipation φ_NO) was relatively stable. At the seasonal scale, at the early stage of the growing season (May-June), φ_PSⅡ and φ_NPQ partitioning is relatively uniform, φ_NO was higher and remained stable. Maximum quantum yield of PSⅡ photochemistry (F_v/F_m) declined. In the mid-growing season (July - September), August φ_PSⅡ significantly decreased and φ_NPQ rose. At the end of the growing season (October), φ_PSⅡ was lowest, φ_NPQ was highest, and φ_NO value was higher and more stable. F_v/F_m declined. Conclusion: On the daily scale, the energy partitioning of photosystem Ⅱ is mainly affected by PAR and T_a, while it is less regulated by RH and VPD. At the seasonal scale, energy partitioning is mainly regulated by the phenological period. F_v/F_m is significantly correlated with PAR_max (R² = 0.13, P < 0.01), T_a variation (R² = 0.16, P < 0.01) and soil moisture content (SWC) (R² = 0.19, P < 0.01), indicating that high radiation, extreme temperature and drought are the main environmental stress factors limiting the photosynthetic physiological state of Salix psammophila. Energy partitioning is likely to be caused by the difference between the short-term regulation mechanism such as photosystem Ⅱ lutein cycle and the long-term regulation mechanism such as chlorophyll. The results enrich the physiological plasticity theory of desert plants in response to environmental fluctuations and provide a scientific basis for vegetation restoration in semi-arid regions.

Objective: In order to further improve the background information and promote the safety evaluation and application of transgenic insect-resistant Populus nigra, flanking sequence of T-DNA insertion sites were isolated in two lines (n12 and n222 with BtCry1Ac). Method: The flanking sequences of exogenous gene insertion sites were separated by hiTAIL-PCR(high-efficiency thermal asymmetric interlaced PCR), and the insertion sites were determined by comparing the genomic sequences of P. trichocarpa. Two pairs of specific PCR primers were designed according to the flanking sequence of insertion sites, and a specific PCR method was established to detect the expression of genes around insertion sites in transgenic poplar with BtCry1Ac. Quantitative real-time reverse-transcription PCR (qRT-PCR) was used to analyze the expression of genes around insertion sites. Result: PCR and semi-quantitative PCR showed that the BtCry1Ac was stable in the transgenic materials. By comparing the genome sequence of P. trichocarpa, the T-DNA of transgenic poplar n12 was inserted into the second intron of Potri.015G076600 at 10162773 locus on Chr15 and the nucleotide composition was 65% for AT content. The integration locus of n222 was 41596184 in the gene spacer of Chr01 and the nucleotide composition was 69% for AT content. Specific PCR detection showed that n12 could amplify 709 bp (transgenic) and 1 159 bp (non-transgenic) specific bands, n222 and its hybrid offspring 1 265 bp (transgenic) and 1 827 bp (non-transgenic) specific bands, while the control could only amplify non-transgenic specific bands. The expression of Potri.015G076600 (serine-protein kinase, SPK) at n12 insertion site was up-regulated 4.3 times and that of nearby Potri.015G076700 (ataxia telangiectasia mutated family protein, ATM) was down-regulated 20 times, those may be involved in the regulation of poplar growth rate. Potri.001G395700 (isoflavone-7-O-β-glucoside 6″-O-malonyltransferase, IBG) and Potri.001G395800 (PIF1-like helicase, PIF) were up-regulated in n222 and its hybrids with P. deltoides 'Danhong'. Conclusion: The T-DNA of n12 and n222 preferentially inserted into AT rich regions, while the deletion of T-DNA vector boundary sequence caused the change of genes expression near the insertion site. And the specific detection method provides a basis for the management and monitoring of transgenic P. nigra with BtCry1Ac.

Objective: Potential risks may exist in field plantings of the transgenic trees, four aspects were comprehensively investigated, including the genetic stability of different exogenous genes in the transgenic poplars and the risk of transfer of the exogenous genes to soil microorganisms, the impact of transgenic poplar on soil microbial community and allelopathy to wild plants, the safety of the three types of transgenic poplars for field release were evaluated as a case study for the safety assessment and field release of transgenic trees. Method: The three exogenous genes encoding different resistance proteins (PeTLP, Cry1Ac, ATGols) were constructed into plant expression vector pGWB9. Agrobacterium tumefaciens LBA4404 was used to infect the leaf discs of poplar trees of Nanlin895 (Populus deltoides×P. euramericana 'Nanlin895'), and the positive plants were screened. A total of 13 lines of three types of transgenic poplar Nanlin895 (TLP, Bt, Gols) were obtained and cultured in greenhouse for 1 year. The stem segments were cut and planted in the experimental field. Randomized block design and split-plot design were used in the field planting. The environmental conditions and growth status of the transgenic trees were recorded during the 20 month test period. Leaf samples and soil samples surrounding the sample trees of each transgenic lines and control trees were collected regularly. The genetic stability of three exogenous genes in transgenic poplar was detected by PCR technology, and the total DNA of soil microorganism was extracted for PCR detection of the three exogenous genes, to evaluate the risk of exogenous genes transfer to soil microorganisms. Plate counting method was used to analyze the composition and change of soil microbial community, and the influence of transgenic poplars on soil microbial community was evaluated; the allelopathy of transgenic poplars on wild plants was simulated by 'sandwich' method with lettuce seeds, and the development data of radicle and hypocotyl of lettuce seeds were recorded and analyzed in order to evaluate the impact of transgenic poplars on ecological diversity. Result: The environment conditions of the test field were relatively stable, and there was no extreme weather affecting poplar growth. The growth trend of transgenic poplars was basically consistent with that of the control (poplar Nanlin895), and no significant difference of tree height was found between the transgenic trees and their respective control. The exogenous genes in the transgenic trees were stable, and gene transfer from transgenic trees to soil microorganisms was not found. The quantity of soil microorganisms was significantly affected by temperature and precipitation (P < 0.05), and the community structure and growth of soil microorganisms were not significantly affected by the transgenic trees. The leaves of the transgenic trees with three different exogenous genes had no significant effect on root and hypocotyl growth of the lettuce seeds. Conclusion: Bt, TLP and Gols transgenic trees of poplar Nanlin895 had no obvious environmental hazards in the field testing.

Objective: The genes encoding 4CL1(4-coumarate:coenzyme A ligase) and CCR (coumaryl:coenzyme A reductase) were ligated to form the fusion gene 4CL1-CCR. The complex enzyme 4CL1-CCR encoded by the fusion gene was analyzed in vitro, it was found that the complex enzyme has catalytic activity of 4CL1 and CCR. It was proven that in Escherichia coli the 4CL1-CCR has efficiently catalyzed the formation of the corresponding aldehyde from phenolic acids such as coumaric acid. On this basis, we studied the function of the fusion gene in tobacco(Nicotiana tabacum), mainly revealing the influence of the fusion gene on the total amount of tobacco lignin, monolignols composition and morphological of tobacco xylem. Method: The content of monolignols in tobacco stems were analyzed using GC-MS. The lignification of tobacco stems were observed by phloroglucinol-HCl staining and autofluorescence of lignin. The expression analysis of key genes involved in lignin biosynthesis in transgenic tobacco was carried out by semi-quantitative PCR. Result: The total amounts of G+S in the stem of transgenic tobacco plants were increased 10.89%-36.44%; the monolignols tests showed a significant increase of G-unit in all transgenic tobacco plants, but S-unit change was not significant. Through the anatomical analysis of the tobacco stems, it was found that the number of xylem cells and the cell wall thickness were increased in the transgenic tobacco plants. However, the lignin deposition pattern did not change. The region with high lignin density was still the cell corner and the compound middle lamella, and the region with low lignin density was the secondary cell wall. Semi-quantitative PCR analysis showed that the expression of C3H, CAD and COMT in the transgenic tobacco plants was increased compared with WT, while the expression of F5H, the key gene for the conversion of G-unit monolignol to S-unit, did not change significantly. Conclusion: Fusion gene expression increased the total amount of G+S lignin and the number of xylem cells, but did not change the distribution patterns of lignin deposition density.

Objective: Ent-kaurene oxidase (KO) is the key enzyme of gibberellins(GAs) biosynthetic pathway and the target enzyme of the plant GAs biosynthesis inhibitor paclobutrazol. Blocking of KO gene in the GAs biosynthetic pathway will affect the normal growth of plants. In this research, we cloned and analyzed the expression of CcKO (Caca0733S0131)gene and its promoter in Carya cathayensis, which is beneficial to further explore the function of CcKO in plant growth and development, especially the biological function related to plant height regulation, so as to help the creation of superior new germplasm of C. cathayensis. Method: The somatic embryos of C. cathayensis were used to clone the sequence of KO gene and its promoter by homologous recombination and PCR amplification. 35S∷CcKO∷GFP overexpression vectors and CcKOpro∷GUS expression vectors were further constructed. The amino acid sequence of this gene was obtained by BLAST online tool, and bioinformatics analysis and homology analysis were performed as well. Furthermore, the overexpression vector and promoter expression vector were transformed into Juglans regia somatic embryos which was mediated by Agrobacterium, and the plant regeneration experiments were carried out to obtain the positive regenerated plants to further analyze the biological functions of CcKO. Result: A C. cathayensis CcKO open reading frame (ORF) was obtained, which was 1 563 bp and encoding 520 amino acids and molecular weight was 59.076 kDa. Amino acids homology analysis exhibited that CcKO contained a core functional domain of cytochrome P450 FXXGXRXCXG and transmembrane region near the N-terminus. BLAST analysis indicated that the amino acid sequence of CcKO was 96% homologous with JrKO, while 71%, 79%, 77% and 76% homologous with the amino acid sequences of Pyrus bretschneideri, Malus domestica, Castanea mollissima and Quercus suber. Heterologous genetic transformation of J. regia somatic embryos: The expression vector of CcKOpro∷GUS was successfully transferred into walnut somatic embryos by GUS staining and PCR verification, and CcKO gene was mainly located in vascular bundles; The overexpression vector of 35S∷CcKO∷GFP was successfully transformed into walnut somatic embryos by fluorescence detection and PCR verification; The phenotypic analysis showed that the plant height of the positive regenerated plants was significantly higher than the control. Moreover, the higher the expression abundance of CcKO, the higher the plant height. Real-time quantitative PCR and related analysis showed that the expression of the gene has spatially differences, and the expression level of stem was significantly higher than other tissues, and KO overexpression could increase the expression of GA20ox and decrease the expression of GA2ox in the GAs biosynthetic pathway of the J. regia positive regenerated plants. Conclusion: The coding region of CcKO was 1 563 bp and encoded 520 amino acids. The amino acid sequence encoded by this gene has the highest homologous with J. regia JrKO amino acid sequence, with the homologous of 96%; The promoter expression vector showed that the gene was mainly located in the vascular bundle. Real-time quantitative PCR and related analysis showed that the relative expression of KO mRNA in J. regia positive regenerated plants was significantly increased, and the regenerated plants showed obvious elongation characteristics as well. Moreover, the overexpression of CcKO in regenerated plants could result in the up-regulation of GA20ox expression and the down-regulation of GA2ox expression. The results of this study provide a basis for further analysis of the role of this gene in the growth and development of C. cathayensis and J. regia.

Objective: Effects of crop tree tending and thinning on growth of forest stand and single tree for typical natural secondary forest Quercus mongolica in Changbai Mountain was discussed, in order to provide a basis for reasonable forest management activities and to promote the restoration and sustainable management for natural secondary forests. Method: 16 plots of 0.09 hm² (30 m×30 m) were set up in the Wangqing Forestry Bureau of Jilin Province in August 2013, to carry out crop tree release and thinning test. According to the thinning intensity, 4 levels of treatments had been set: weak (5%), mild (10%), moderate (20%) and control, each treatment had 4 replicates. Using remeasurement data in 2016, the early effects of different tending thinning intensities on the growth of stand were comparatively analyzed. Result: After 3 years of thinning treatment, the growth rate and accumulation rate of forest stand in thinning plots were significantly higher than those in control plots. There was no significant difference in three thinning intensities. DBH growth rate and volume growth rate of single tree in thinning plots were significant higher than those in control plots, which were increased with the increase of thinning intensity. The DBH growth rate of Quercus mongolica and Pinus koraiensis under moderate thinning was 1.51 and 1.67 times that of the control, respectively. The DBH growth rate and volume growth rate of seedlings, small-size trees and middle-size trees were significantly promoted by crop tree tending and thinning, and there was no significant difference for large-diameter trees between thinning and control. Regarding the crop trees, the DBH growth and volume growth rate were significantly bigger than those of control. The DBH growth of crop trees was 1.28-1.32 times of that of non-crop trees, while the volume growth was 2.13-2.69 times of that of non-crop trees. As the free growth space of crop tree increased, the DBH and volume growth of the crop trees were also increased. Conclusion: Thinning based on single crop tree could not only promote the growth of basal area and volume for forest stand, reduce the average DBH of damaged trees, increase the number of recruitment trees, but also significantly increase the growth of DBH and volume of single tree, especially the crop trees. The decisive factor affecting the growth of crop tree might be the free growth space. When Quercus mongolica, Tilla amurensis, and Fraxinus mandshurica were selected as crop trees, it would be suitable for the complete canopy release activity from four directions. When the Pinus koraiensis was selected as crop tree, it would be suitable for the incomplete canopy release activity from 2-3 directions.

Objective: In view of the problems that the recognition accuracy of remote sensing tree species under the complex stratospheric structure and high forest density of subtropical forest is not high, and that the performances of different classification algorithms to the recognition of different tree species are various, the method of multi-classor combined tree species recognition of high spectral resolution combined with high spatial resolution data was investigated to promote the in-depth application of multi-source data in the field of forest resource survey and monitoring. Method: Taken Huangfu Mountain National Forest Park as research area, and assisted with data of GF-6 PMS and GF-5 AHSI, digital elevation model(DEM) and forest resource survey data, the effective tree species recognition algorithm of multi-classor adaptive for object multi-source data, which is under the conditions of subtropical natural secondary forests, complex coronary structures and high forest density, was built in this study. First of all, the GF-6 PMS data was divided according to object-oriented multi-scale and combined with the field survey data by using the graph cutting algorithm(GC) to select the sample. Then, it was carried out to use GF-5 AHSI data to extract 26 vegetation index features(VIF), to use GF-6 PMS data to extract 128 parties of each band texture features(TEF), and combined with 304 bands of GF-5 AHSI with removal of bad band as spectral features(SF) and 3 DEM-built terrain factors as terrain features(TRF, factor features according to various inter-class separability were selected and 10 recognition schemes based on characteristic selection results were built. Finally, the weight adaptive voting combination classifier(WACC) using near-category(KNN), support vector machine(SVM), Bayesian classification(Bayesian), classification regression tree(CART), and random forest(RF) was constructed to recognize tree species based on 10 classification schemes and to verify the accuracy of tree species identification. Result: Under the linear discriminant analysis model, the discriminant accuracy was identified to tend to be stable when the factor of spectral characteristics, texture features and vegetation index characteristic were increased to 28, 12 and 10, respectively. The spectral characteristic factors with better recognition ability for the tree species were mainly concentrated in the red light and near-infrared bands, the texture feature factors mainly concentrated on mean, entropy and angular second-order moment, while the vegetation index features were mainly concentrated on the index of characterization greenness, carbon attenuation, and coronary aquifer aquifers. The overall accuracy of tree species recognition in the weight adaptive classifier combination algorithm was 87.51%, and the Kappa coefficient of 0.854 was better than that of the single classifier algorithm. The overall accuracy obtained by different characteristic factor schemes under each classification algorithm was as follows: SF+TEF+VIF > SF+TEF+VIF+TRF > SF+TEF+TRF > SF+VIF > SF+VIF+TRF > SF+TEF > SF > SF+TRF > VIF > TEF. Conclusion: he weight adaptive classifier combination algorithm under the combination of SF-TEF-VIF features could effectively identify tree species in subtropical natural secondary forests, and enjoy good recognition accuracy and credibility, and the data of GF-5 AHIS and GF-6 PMS would present a good application potential and prospect in the fields of forest resource survey and monitoring.

Objective: Based on the game theory, the study of relative growth relationships between height and diameter of juvenile Korean pine, which was planted in Mongolian oak broad-leaved mixed forest, was carried out to provide a technology support for the regeneration and cultivation of Korean pine from broad-leaved mixed forest. Method: The total competitive trees, including Korean pine, Mongolian oak, broad-leaved trees excepted Mongolian oak and coniferous trees excepted Korean pine around 5 m radius of objective tree Korean pine, were selected through 11 plots with a hectare each of Mongolian oak broad-leaved mixed forest. Then basal area weighting distance, diameter and height corresponding to these competitive trees were calculated for constructing systems of linear simultaneous equations between height and diameter of Korean pine. Furthermore, the model was tested with cross validation and evaluated with several statistical indicators. However, the interactions between height and diameter growth of Korean pine were discussed from the insight of the game theory. Result: Growth competition model between height and diameter were excellent in fitting data. The result from method of ordinary least squares(OLS)was slightly better than that of seemingly unrelated regression(SUR). The slopes from diameter and height of Korean pine were positive and highly significant, which reflected that internal genetic factors of Korean pine had a beneficial relationship of mutualism and predominated in that. Accordingly, the perturbation from external environment was secondary. The coefficients of L, D, and H from Korean pine, Mongolian oak and broad-leaved tree were significant, and however took the opposite values for height and diameter of Korean pine, which indicated a harmful relationship of parasitism. Differently, the coefficients from coniferous tree were non-significant, which led to a relationship of synergism. Conclusion: Growth competition model between height and diameter not only objective ly described relative growth relationships of Korean pine in Mongolian oak broad-leaved mixed forest, but also revealed the resource allocation of height and diameter growth under the conditions of genetic factors or the disturbance from external environments, combining with the game theory. Furthermore, Mongolian oak broad-leaved mixed forest provided a stable environment for Korean pine.

Objective: In order to solve the problems of frequent occurrence of slow matching speed, high error matching rate and poor matching quality when processing aerial photographic images in forests of UAV in low altitude by directly using photogrammetric software, the article started from the aerial photographic image features in forests in low altitude to explore an image matching strategy suitable for UAV's aerial photographic images in forests. Method: The homography restraints among image pairs were built with the aid of UAV's POS data based on the related principles of photogrammetry and computer vision. This is a partition matching strategy of which several corresponding subareas are divided according to certain location distribution rules and each sub area is regarded as an independent image to be processed during the feature extraction and matching processes. Meanwhile the GIS space analysis algorithm was introduced into the feature matching processes to explore the characterization and evaluation of location distribution quality of feature points. Result: Under the software programming environments of the same work station Python 3.7 and OpenCV 3.4.2.16, the contrast experiment was implemented by using the six kinds of characteristic operators of ORB, FAST, SURF, SIFT, KAZE and AKAZE, with collaboration of the partition matching strategy and the sampling matching strategy under the common classification to the aerial photographic images of broad-leaved forest and coniferous forest with the same parameters set. The results showed that the average matching speed of the six kinds of operators in collaboration with partition matching strategy was increased by 11.53%, the average matching rate was increased by 0.83%, and the average location distribution quality was improved by 2.46%. Conclusion: The low altitude UAV's forest images presented different features from the common mapping aerial photographic images, where the matching methods of the common mapping images couldn't be used discriminately. The partition matching strategy of the original resolution rate images used by this article narrowed matching scope and increased matching speed while keeping the image details; meanwhile this strategy improved the location distribution quality of the feature points and lowered the error matching rate by using the homography restraints built with UAV's POS data. The effectiveness and flexibility of this strategy was verified by collaborating with the experiments of the six kinds of characteristic operators and the irrelevant independence from the characteristic operators. The optimal effect result collaborating with the strategy by AKAZE operator was obtained, which could provide references for the related studies of the aerial photographic image processing in forests.

Objective: A fine-tuning convolution neural network method based on transfer learning technology was proposed for automatic classification of forestry images, which was expected to be beneficial for forestry management department to make reasonable disposal plan or scheduling decision in a series of forest incidents, so as to improve the level of forest management and to protect forest resources and ecological safety. Method: Pre-training with the large-scale image set(ImageNet), CaffeNet was trained with fine-tuning by using the forestry image data. The first 5 layers' parameters of the model were obtained by migration, including convolution layer, activation function and pool layer; and the parameters of full connection layer and Softmax were determined by training. Result: CaffeNet model of the pre-training fine-tuning convolution neural network presented a good classification accuracy for forestry images. With four classes forestry image data sets established according to forestry business requirements, the average recognition accuracy was stable to 97.5% after a certain number of iterations. Further feature visualization showed that the trained feature maps obtained from different layers of the deep convolution neural network got the forestry image classification ability from different aspects. Compared with the traditional feature extraction method, our method's recognition rate was also increased by 10.8% even adding one class into the number of forestry categories. Conclusion: It might be feasible to classify the forestry images by using CaffeNet model. Compared with the traditional feature extraction and recognition methods, the forest image classification model based on convolution neural network could have a stronger feature extraction ability and classification ability. So it would play an important role in the application of forest management in the future.

Objective: In this study, Beauveria bassiana strains with high pathogenicity against Monochamus alternatus adults were screened in order to control M. alternatus effectively. Method: The Monochamus alternatus larvae infected by the pathogenic fungus were collected, and the pathogenic fungus was isolated and purified in PDA medium at 25 ℃. The robust Monochamus alternatus adults emerged in 5-10 d (at 25 ℃, relative humidity 60%, photoperiod 16L:8D) were used as bioassay object of pathogenic fungus lethal effect. The spores of pathogenic fungi cultured on PDA medium were collected and dissolved in 0.05% Tween 80 solution to prepare a spore suspension with a final concentration of 1×10⁶~3×10⁶ or 1×10⁷~3×10⁷·mL^-1, respectively, and 0.05 % Tween 80 solution was used as a blank control. Two methods (applying and spraying spore suspension on branches) were used to treat the adult Monochamus alternatus, and the virulence of the strains was evaluated based on the cumulative corrected mortality. The line graph was drawn by R package "ggplot2". ITS1 and ITS4 were used to amplify the conserved sequences of fungi, and sequenced after connection and transformation. The phylogenetic tree was constructed by using the software muscle to compare sequences and the maximum likelihood method in MEGA software. Result: A total of 23 Beauveria bassiana strains were isolated from the 23 infected Monochamus alternatus larvae, and 6 strains with a cumulative corrected mortality rate of more than 30% over 18 days were preliminarily screened by spraying method. Two strains, B7 and B9, with high spore production (14 d, 10⁸·cm^-2) were selected. The virulence test results showed that the cumulative corrected mortality of B9 strain on the 12^th day reached 100%, while the cumulative corrected mortality rate of B7 strain in that time was about 50%±10%. Thus the lethal rate of B9 strain was significantly higher than that of B7 strain. The results of ITS amplification and sequencing showed that the homology with Beauveria bassiana was 99%. The phylogenetic results also showed that B9 strain and B. bassiana clustered on the same branch. Combined with the morphology, NCBI Blast comparison results and phylogenetic tree, the B9 strain was determined to be Beauveria bassiana. Conclusion: In this study, the strains of Beauveria bassiana with high virulence to adults of M. alternatus were successfully screened. It is expected that the use of entomopathogenic fungi to control M. alternatus adults has a good application prospect, but the practical application value needs to confirm in further field trials.

Objective: The observation and analysis of the ultrastructure of the antennal sensilla of the male and female of Chouioia cunea (Hymenoptera: Eulophidae) can provide a basis for the research on the olfactory receptive mechanism of the C. cunea and lay a foundation for further exploring the internal structure, mechanism of action and related functions of each sensilla. Method: Scanning electron microscopy was used to observe the morphological structure, type, number and distribution of antennal sensilla of the male and female. A total of 10 males and 10 females were observed, and their antennal sensilla were described, compared and analyzed in detail. Result: The antennae of male and female were significantly different, with female of 11 sections, male of 12 sections, and male had swollen antennae scape. From the base of the antennae to the end of the antennae, the number and types of the sensilla increased gradually, among which the number and types of the sensilla on the flagellum were the most abundant. In terms of the types of the male and female sensilla, the female had two more sensilla than the male, which were sensilla mammilliformia Ⅱ and sensilla coeloconica. As for the morphological structure of the male and female sensilla, the sensilla trichodeaⅠof the female were longer than that of the male. The sensilla mammilliformia Ⅰ of the male was significantly longer than that of the female. The sensilla mammilliformia Ⅲ was newly discovered in our study, and there were significant differences in the morphological structure between male and female. The number of antennal sensilla of the female was about twice that of the male. There were significant differences in the number of Sensilla trichodea Ⅰ, Ⅱ, sensilla placodea, sensilla chaetica, sensilla mammilliformia Ⅰ and Ⅱ between male and female. The most abundant sensilla on the female antennae were the sensilla trichodea Ⅰ, while the sensilla trichodea Ⅱ had the largest number on the male antennae. From the perspective of the distribution of sensilla, sensilla trichodea Ⅰ was distributed in all the flagellar segment of the female antennae, but it was mostly distributed in the funicle of the male. The sensilla trichodea Ⅱ is distributed in each flagellar segment of the antennae of the male, but it is mostly found in the clava of the female antennae, but not in the funicle. Conclusion: The phenomenon of sexual dimorphism of antennal sensilla is obvious between the male and female, and the morphological structure, types, number and distribution of the sensilla are different, which could be related to the different functions of the antennal sensilla of male and female.

Objective: Wood formation is mainly controlled by the number of cambium cell division, which determines the biomass production and wood quality. The differentiation from cambium cell to mature xylem as the main line, this article discussed the wood formation processes of Pinus elliottii with aims to provide scientific guidance for the tree growth development, wood genetic improvement and wood resourse utilization of P. elliottii plantation. Method: In this paper, we mainly used transmission electron microscope (TEM) to investigate the activity regularity of cambium in detail during the wood formation of P. elliottii at the cellular ultrastructure level. Result: P. elliottii underwent annual cycles of cambial during periods of cambial activity and dormancy. The appearance of dividing fusiform cells in cambium indicated that the cells broke dormancy into recovery activity. From the end of February to the end of March, the period of transition from dormancy to activity, namely the recovery period, some autolysis occurred in the radial walls of the cambial cells, especially at the cell wall junctions. At this time, there was no significant difference between the radial wall and the tangential wall of the cambium fusiform cells that showed oval or nearly round. During the activity period from the beginning of April to the end of October, the whole cambial fusiform cells were highly vacuolated and the cell shape became irregular, both the radial wall and the tangential wall became thinner, the tangential wall was thinner and inconspicuous, the lipid droplets and starch granules decreased dramatically. The cambial activity reached the strong active phase in mid-June, the number of cells in the cambium was significantly increased and the secondary wall began to thicken. At this time, the protoplasts basically disintegrated and disappeared. The cells were dormant at the end of October to the end of the next year, the number of layers of cambium was significantly reduced, only contained 1-2 layers of thick-walled fusiform cells, the radial wall and tangential wall of the fusiform cells were significantly thickened and the inclusions of the cells began to accumulate. During the entire active period, the radial wall was significantly thicker than the tangential wall, while the differences were more obvious during the dormant period. A notable feature of the cells at the onset of cambial activity was the thinning of the cell wall, especially the radial wall. There were pine needles falling during the whole growing season and new pine needles were produced during the dormancy period, indicating that there was no obvious correlation between pine needle production and shedding and dormancy and activation of the cambial cells. The mature ray cells in the secondary xylem always contained more inclusions, and the protoplasts did not show any recession, indicating that the ray parenchyma cells maintained a high activity even after lignification for several years. Conclusion: There is a clear annual cycle of cambial for slash pine, with periods of cambial activity and dormancy. From the end of February to the end of March, it is a recovery period, and the activity period is from the beginning of April to the end of October, which is the period of slash pine wood formation. The cambial activity reaches the strong active phase in mid-June, the number of cells in the cambium is significantly increased and the secondary wall begins to thicken. The cells are dormant at the end of October to the end of the next year, the number of layers of cambium is significantly reduced, only contains 1-2 layers of thick-walled fusiform cells. In different periods of cambial activity, there are significant differences in number of layers of cambium, the radial wall and tangential wall of the fusiform cells and its cell inclusions.

Objective: This paper was implemented to grasp the situations and determinants of the subjective well-being in state-owned forest area under full stop commercial logging, in order to provide a decision reference for testing the effects of ecological project, improving ecological policy and weighing the residents' livelihood of forestry. Method: Based on 657 monitoring data from state-owned forest reform, the basic characteristics of subjective well-being in state-owned forested area by using cross-linked tables were analyzed. Based on the capability approach of Amartya Sen, a theoretical model of influencing factors of subjective well-being in state-owned forest area was constructed. The factors influencing income satisfaction and life satisfaction of state-owned forest area were analyzed using ordered Logit model. The marginal effect analysis method was used to explore the influence degree of each factor. Result: Firstly, subjective well-being of state-owned forest area was not high, and lower than the subjective well-being of Chinese farmer and citizen. Secondly, the policy had different impacts on workers' income, the lag of infrastructure construction restricted the improvement of subjective well-being. The per-capital income level of forest area was similar, but the consumption level was significant, the number of part-time jobs was increasing. Thirdly, education, income, social security, policy equity and support policies had significant effects on income satisfaction in state-owned forest area. Gender, marriage, health, income, living condition, traffic, part-time job and social security had significant effects on life satisfaction in state-owned forest areas. Conclusion: The level of subjective well-being of state-owned forest area is under farmer and resident, and there are some differences in each dimension of subjective well-being in different forest areas. Full Stop Commercial Logging did not bring the changes of subjective well-being of workers' in state-owned forest area. Income is not the only way of subjective well-being in state-owned forest area, the protective guarantee becomes the core dimension that affects the subjective well-being of workers in state-owned forest area, social security is crucial to the subjective well-being of state-owned forest area, social equity is the leading factor to improve income satisfaction. Individual characteristics, economic conditions and living environments are three important factors to subjective well-being. In the future, the level of protective guarantee of workers and the solid foundation of infrastructure construction in state-owned forest area should be put forward to improve the subjective well-being.

Objective: This study investigated the effects of different concentrations of betaine (BT), salicylic acid (SA), methyl jasmonate (MeJA) and calcium chloride (CaCl₂) on stress resistance of Erythrophleum fordii seedlings under drought stress, in order to find a feasible method to alleviate the drought damage of E. fordii seedlings, and provide technical reference for the cultivation and promotion of E. fordii. Method: The annual E. fordii seedlings were used as materials. Different concentrations of BT, SA, MeJA and CaCl₂ solutions were sprayed on the leaves, and then the root system with the culture medium was dipped in a concentration of 30% PEG-4000 solution for simulating a drought stress. Two groups of controls (CK) were set up. CK₁ was sprayed with distilled water on the leaves and the root was maintained in a normal soil environment. CK₂ was sprayed with distilled water on the leaves and the root system was placed in a concentration of 30% PEG-4000 solution. Cell membrane permeability, malondialdehyde (MDA), proline (PRO), soluble protein, soluble sugar, chlorophyll content (SPAD value), and superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) antioxidant enzyme activity of E. fordii seedlings leaves were measured on the 10th day after drought stress treatment. Result: Compared with CK₁, drought stress significantly inhibited the antioxidant enzyme activities of leaves of CK₂, and aggravated the damage of cell membrane by drought conditions, resulting in damage to cell membrane structure and destruction of cell membrane function, which led to significant increases in relative conductivity and MDA content of leaves of seedlings. Drought stress was also able to cause the destruction of chloroplast structure, and hence impeded normal photosynthesis. Compared with CK₂, foliar application of signal substances significantly increased the content of PRO, soluble protein and soluble sugar in the leaves, and reduced the water loss caused by drought in leaves of seedlings. In addition, the foliar application of signal substances improved POD, SOD and CAT antioxidant enzymes, andactively and effectively removed excess reactive oxygen species in cells, avoided membrane lipid peroxidation, significantly reduced leaf MDA content and relative conductivity, normalized cell membrane system metabolism, and alleviated the damage caused by drought stress on leaves of seedlings. The foliar application of signal substances increased the SPAD value of leaves and reduced the inhibition of photosynthesis by drought. With the increase of the treatment concentration, except for the CaCl₂ solution, the other three kinds of exogenous signal substances hada tendency to attenuate the drought damage to the seedlings. Conclusion: Foliar application of 500 mg·L^-1 BT, 100 mg·L^-1 SA, 1 mmol·L^-1MeJA, and 5 mmol·L^-1 CaCl₂ solution can significantly alleviate drought stress and improve the drought resistance of E. fordii seedlings.

Objective: This study aimed to explore the fruiting and seed germination characteristics of Rhododendron changii and their response to environmental factors, so as to provide scientific basis for revealing the endangered mechanism and formulating conservation strategies. Method: Fruiting quantity characteristics of population and individual plants, cone and seed characteristics were investigated, and their correlations with environmental factors were analyzed. The effects of maternal plant traits, light intensity, fruit traits and seed morphological phenotype on seed germination were examined. Also, the influence of environmental factors such as different light and temperature during germination and seed soaking treatment with GA₃ at different concentrations were discussed. Result: 1) Fruiting characteristics of R. changii population growing in shrub and mossy dwarf forest were better than those in broadleaf forest (P < 0.05), and the percent of seed bearing mother trees ranged from 39.58% to 66.67% in four populations. The stratification effect of seed setting in canopy was obvious, and the fruit setting rate was between 43.90% and 58.62%, and the low seed plumpness rate varied from 9.89% to 15.71%. Morphological phenotype of seeds from the same maternal plant showed continuous variation, and the seeds with different morphological phenotypes possessed great breeding potential. 2)Fruiting was mainly affected by the limitation of light resources. The light condition of maternal plants was positively correlated with fruit setting rate, full-developed seeds rate and seed width (P < 0.01). The less light was, the lower percentage the full-developed seeds was and the more the oblong seeds (seed width/seed length < 0.4) were. 3)The seed germination characteristics were mainly affected by the morphological phenotype of seeds, followed by light condition and age of the maternal plant and the degree of fruit cracking. That is, the greater the ratio of seed width to seed length and the more sufficient lighting of the maternal plant, the higher the seed germination rate and vigor index of seedlings. The older the maternal plants and the more complete the fruit cracking, the lower the seed germination rate and vigor index of seedlings. In addition, the germination ability of oval seeds (seed width/seed length ≥0.4) was better than that of long-round seeds. 4)The seed of R. changii had light-requiring physiological dormancy. The germination rate under dark conditions was significantly lower than that under light conditions. The seed germination rate and seedling vigor index were positively correlated with light. The germination rate and seedling vigor index were significatly increased through seed soaking treatment with GA₃ in the suitable concentration range of 400-600 mg·L^-1. The seeds had a wide range of adaptability to temperature with germination just at 5 ℃, but the proportion of deformed seedlings was larger under low temperature conditions, and the optimum temperature for germination was 20-25 ℃. Conclusion: The intense light competition in the natural community leads to continuous decline of suitability of the habitat, and gradually tends to small populations. Limitation of light resources affects fruiting characteristics, causing the decline of seed yield and quality, and hence decline of the sexual reproductive ability gradually. Under the adverse natural conditions such as weak light under the forest, the transformation from seed to seedling is inhibited. Seeds germination starts at low temperature but with low germination efficiency, which increases the risk of population. Thus, forest trees should be thinned and surface litter should be cleared to improve the light condition of population and soil seed bank. In order to maintain the population development, artificial propagation should be implemented. The seedlings could be cultivated with yellowish-green fruit with slightly cracked capsules at the early stage of fruit ripening and oval seeds.

Objective: In order to solve the problems those the evaluation of the existing single wood permeability is greatly affected by the observer's perspective and subjectivity, and it is difficult to establish a unified judgment standard, based on the digital image of trees, this study aimed to identify and integrate the structural characteristics of the single tree. The inner and outer areas formed by the canopy were used to quantitatively evaluate the canopy permeability, with an expect to provide technical supports for the health monitoring and growth status analysis of single trees. Method: Taking cedar as the research object, the image of a single tree was obtained using Surface Pro 4. Using a pressure-sensitive stylus to manually circle the canopy area in the image, and further graying and binarizing the circled area, the binarized image of a tree was obtained. By using morphological operations, the smooth outline of the canopy was obtained, to determine the vertical symmetry axis of the canopy, establishing a mirror image of the canopy based on the symmetry axis. By using the DelaunayTri function, the triangulation of the canopy was obtained, and then the canopy Convex hull was also obtained by using the convexhull function to obtain. The shortest distance from each point on the smooth outline to the convex hull was calculated by starting from any point in the smooth outline and walking in a clockwise direction.By using K-means clustering algorithm to determine deep and light depressions, and calculating deep depressions density, the area within the smooth outline of the canopy was marked as a connected area. By using K-means clustering to divide the connected area into large holes and small holes, the density of large holes and small holes was calculated respectively. The three coefficients of density and pore density were given different weights to quantitatively evaluate the permeability of single wood. Referring to the experience of forestry experts and tree growth rules, three coefficients of deep depression density, large hole density and small hole density in the canopy profile were used to quantitatively evaluate the single tree permeability. Taking into account the effects of deep depression on the crown shape and permeability were higher than those of the large hole, a greater weight was given to the depth depression. In addition, the contribution of the small hole to the transparency was added, 6 canopy images were obtained from 6 angles of 0°, 30°, 60°, 90°, 120°, 150°. The average T_ca was used as the permeability coefficient of the single tree to reduce the fluctuation of the transparency caused by the change of viewing angle, and the true state of the single tree was reflected as accurately as possible. AutoCAD 2010 combined with Photoshop CC 2017 was used to design the single-wood verification model, and the method proposed in this study were tested and verified. Result: Ideally, the density of small hole, the density of large hole, deep depression density, and permeability was 0.125 0, 0.125 0, 0.162 9, and 0.264 6, using the method propose by this research, the density of small hole, the density of large hole, deep depression density, and permeability was 0.117 8, 0.124 1, 0.164 0, and 0.258 6. The method proposed by this research had an accuracy of up to 97.73%. Conclusion: The method proposed by this research, had a fast measurement and a small manual workload. It was expected to provide a technical support for the health monitoring and growth status analysis of single trees. At the same time, the research ideas and method could also be applied to other trees and crops. The monitoring analysis also might have a certain practical value.

Objective: The aim of this study was to investigate the home range, habitat selection, and migration routes of the wild Bactrian camel (Camelus ferus)in the Kumtag Desert, China. Method: Three wild camels in Kumtag Desert were outfitted with satellite tracking collars and monitored from 2014 to 2016. Minimum convex polygon (MCP) was used to calculate home range. Kernel model was used to analyse habitat selection. Result: During the entirety of the study period, the 100% MCP home range of three wild camels reached 7 596.44 km², 8 152.10 km², and 1 162.17 km², respectively. In terms of season, the home ranges were the largest in spring, followed by winter, and then autumn and summer. Different individual used separated core areas but exhibited some overlap with one another. Individual camels picked different habitats in different seasons. For example, while all three camels moved to the cooler Altun Mountains in summer, however they did not all move to the warm Aqike Valley in winter. Home range hotspots were centered around watering holes during spring and autumn. Most migrations occurred during the breeding season, peaking in April. The wild camels were able to complete a migration from north to south movement across the Kumtag desert within 30 hours. Conclusion: Based on the analysis of habitat utilization of wild camels, the areas and migration routes of wild camels in different seasons are preliminarily determined. The determination of key areas will provide a basis for the protection and management of wild camels and their habitats. Due to limited samples and data, further research is necessary to reveal the habitat selection and migration mechanism of the wild camel population in Kumtag Desert, China.

Objective: Unmanned aerial vehicle (UAV) remote sensing combined with machine vision is used to identify large gerbil holes in desert forests,and the technology can automatically,accurately and efficiently acquire the distribution of rat holes and provide support for improving the efficiency of scientific rodent pest management. Method: In this paper,a method for identifying and locating rat holes was proposed by combining machine vision with remote sensing of unmanned aerial vehicle (UAV),which is suitable for the typical haunt of rodents of desert forests in the southern edge of Gurbantunggut Desert. The method includes two schemes for identifying rat holes using the YOLOv3 network and its lightweight solution YOLOv3-tiny network. First,the appropriate images were selected from the two low-altitude remote sensing images,and the images were cropped to 416×416 pixel images. The rat holes in the images were labeled with a labeling tool,and data set of the gerbil holes in desert forest was constructed. Then,k-means clustering algorithm was used to cluster the number and aspect ratio dimensions of target candidate boxes in the gerbil hole data set,so as to select a prior box suitable for the data set. Finally,the adjusted parameters were used to train the network,and the target detection precision (P),recall (R) and average precision (AP) of the rat hole data set were used as the evaluation indexes of the target detection algorithm. Result: The average accuracy of YOLOv3 network on the rat hole data set is 92.37%,the average accuracy of YOLOv3-tiny is 85.86%,and the AP of YOLOv3 network is 6.51% higher than that of YOLOv3-tiny network,but the number of YOLOv3-tiny parameters is only 1/13 of that of YOLOv3. The average time for the YOLOv3 network to detect a single image in this paper's hardware environment is 0.83 s,and that detection time for YOLOv3-tiny is 0.22 s. Conclusion: The above results indicate that UAV remote sensing combined with YOLOv3 network and YOLOv3-tiny network can realize the identification and location of large gerbil holes,effectively monitor the distribution of rat holes,and make up the deficiency of traditional methods in monitoring rat damage and improve the real-time and flexibility of monitoring gerbil damage.