2022 Vol. 35, No. 5
Display Method:
[Abstract]
[FullText HTML]
[PDF 4447KB]
2022, 35(5): 0-1.
Abstract:
2022, 35(5): 1-13.
doi: 10.13275/j.cnki.lykxyj.2022.005.001
Abstract:
Objective The role of MYB transcription factor family in pigment formation of yellow Paeonia delavayi flowers was analyzed to provide candidate genes for color improvement and molecular breeding of tree peony. Method In this study, members of MYB gene family of P. delavayi were identified and classified based on the transcriptome data of petals. One member of R2R3-MYBs, PdMYB2, was selected as a candidate gene according to phylogenetic tree, homologous sequence alignment and gene differential expression analysis. The function of PdMYB2 was analyzed by subcellular localization, qRT-PCR, transient overexpression, transgenic tobacco and LC-MS/MS. Result A total of 64 MYB genes were identified, including 25 R2R3-MYBs, one R1R2R3-MYBs, two 4R-MYBs and 36 members of MYB-related. The PdMYB2 was found to express in the nucleus and cytoplasm. Overexpression of PdMYB2 in tobacco increased anthocyanin accumulation and up-regulated the expression of anthocyanin-related structural genes NtCHS and NtCHI in petals and leaves. Conclusion PdMYB2 plays a positive regulatory role in the flavonoid biosynthesis pathway, which can promote the accumulation of anthocyanins and increase the expression of structural genes in the flavonoid pathway.
Tree Crown Extraction of UAV Remote Sensing High Canopy Density Stand Based on Instance Segmentation
2022, 35(5): 14-21.
doi: 10.13275/j.cnki.lykxyj.2022.005.002
Abstract:
Objective To obtain canopy information in high canopy density forest by remote sensing images. Method A single tree crown extraction method of UAV remote sensing image based on instance segmentation model was tested. Seven residual networks were selected for feature extraction of the model, and the single tree crowns of pure Chinese fir forests with different canopy density were extracted one by one. Result The results showed that the average boundary AP value and mask AP value of seven instance segmentation models for canopy segmentation of low canopy density forest were 55.89% and 57.29%, respectively. The average RMSE of east-west crown width, north-south crown width and crown area parameters was 0.161, 0.179 and 0.341, respectively. The R2 was 0.912, 0.918 and 0.957, respectively. The average boundary AP value of canopy segmentation and the average AP value of canopy cover of high canopy density forest were 46.00% and 44.45%, respectively. The average RMSE of east-west crown width, north-south crown width and crown area parameters was 0.479, 0.497 and 1.256, respectively. The average predicted R2 was 0.806, 0.762 and 0.936, respectively. Conclusion The extraction accuracy of each parameter is higher than the traditional survey accuracy, and this method can obtain crown information automatically, rapidly and accurately.
2022, 35(5): 22-32.
doi: 10.13275/j.cnki.lykxyj.2022.005.003
Abstract:
Objective To analyze and compare the temporal and spatial differences in soil heavy metal content in the water-fluctuation zone of the Three Gorges reservoir area, study the current situation of metal pollution in this area, and put forward prevention and control measures. Methods The soils in the flooded area (elevation 145-175 m) and unflooded area (elevation 175-185 m) from the water-fluctuation zone of the Three Gorges reservoir area in the Zigui section in 2008, 2014, and 2018 were used for the study. We examined the physicochemical properties and copper (Cu), iron (Fe), manganese (Mn), and zinc (Mn) contents of these samples through the digestion method. Results The results showed that: (1) The contents of soil total nitrogen (TN), total phosphorus (TP) and organic matter (SOM) in the flooded area continued to decrease from 2008 to 2018. The soil pH increased compared with 2008 and it was close to 7 in 2018. (2) As of 2018, the contents of Cu, Fe, Mn and Zn in the soil of water level fluctuating zone have been increasing. The geological accumulation index pollution degree of Zn in the middle and lower part of water level fluctuating zone (elevation 145～165 m) and the soil in the non-flooded area was “strong”; Cu in the lower part of the water level fluctuating zone (elevation 145～165 m) and Zn in the soil in the middle and lower part of water level fluctuating zone and non-flooded area had caused slight ecological risks. (3) The correlation analysis between soil physical and chemical properties and the contents of four heavy metals in water level fluctuating zone showed that the rise of soil pH might bring the risk of increasing the accumulation of four heavy metals. The increase of soil TP might reduce the accumulation of four heavy metals in the soil, while the increase of soil TN content might cause the increase of soil Fe and Mn in the non-flooded area and the decrease of Cu and Zn in the flooded area. Conclusion In summary, the operation of the Three Gorges Dam has caused a decline in the quality of soil nutrients such as reducing nitrogen and phosphorus contents. The status of soil heavy metal pollution in water level fluctuating zone cannot be ignored, especially the ecological risks of Cu and Zn. Therefore, long-term monitoring should be continued, and artificial intervention means such as changing vegetation composition can be considered if necessary.
2022, 35(5): 33-41.
doi: 10.13275/j.cnki.lykxyj.2022.005.004
Abstract:
Objective To investigate the promotion of phosphorus uptake in Camellia oleifera seedlings by mycorrhizal fungi at different inorganic phosphorus levels, and provide a theoretical basis for the study of inoculation with mycorrhizal fungi to enhance phosphorus efficiency of C. oleifera seedlings. Method One-year old C. oleifera was used as the host plant, and young sets of Claroideogolmus etuicatum were inoculated with KH2PO4 (0, 10, 50, 100 mg·kg−1). The effects of inoculation with AM fungi and inorganic phosphorus on phosphorus uptake and grown soil phosphorus fraction of C. oleifera seedlings were investigated. Result Under the conditions of no (0 mg·kg−1), low (10 mg·kg−1), medium (50 mg·kg−1) and high (100 mg·kg−1) phosphorus application, the phosphorus content of mycorrhization C. oleifera seedlings was significantly higher than that of non- mycorrhization. The above-ground phosphorus content increased by 5.64%, 8.14%, 14.28% and 5.79%, respectively, and the phosphorus content of seedling root system increased by 12.85%, 20.01%, 19.63% and 18.09%, respectively. The effects of inoculation with AM fungal treatment, application of inorganic phosphorus treatment and their interaction on soil total phosphorus content, effective phosphorus content and organic phosphorus content were highly significant. Inoculation with C. etuicatum significantly reduced the content of four phosphorus forms, Al-P, Fe-P, Ca-P and O-P in the soil. Under low phosphorus conditions, inoculation of C. etuicatum significantly increased the expression of Pht1;1 gene in leaves and root systems of the seedlings; under medium and high phosphorus conditions, inoculation of C. etuicatum decreased the gene expression of Pht1;1 gene in leaves and root of C. oleifera seedlings. Conclusion AM fungi can alter phosphorus morphology in C. oleifera grown soil, promote the uptake efficiency of effective phosphorus in soil by plants, and participate in regulating the expression of Pht1;1 gene in C. oleifera. The results of this study provide a scientific basis for microbial fertilizer to improve soil phosphorus uptake efficiency of C. oleifera seedlings and reduce phosphorus fertilizer application, which promotes the healthy and sustainable development of C. oleifera industry in China.
2022, 35(5): 42-51.
doi: 10.13275/j.cnki.lykxyj.2022.005.005
Abstract:
Objective In order to select superior families and individual plants which is suitable for planting in Nanjing and surrounding areas for providing a theoretical basis for the oriented silviculture of Cyclocarya paliurus plantations. Method The 3.5-year old germplasm resources of C. paliurus trees were comprehensively evaluated in this study. The 31 families of C. paliurus trees were used as test materials to determine the traits of growth and the leaf contents of total flavonoid, triterpenoid, and polyphenol. And cluster analysis and entropy method were used to screen superior families and individual trees based on the variations in traits. Results Significant variations were observed in tree height, diameter at the base, and the leaf contents of total flavonoid, triterpenoid and polyphenol among different families. Hierarchical cluster analysis showed that the 31 families of C. paliurus were classified into four distinct groups. The C. paliurus families in cluster 1, cluster 2 and cluster 3 could be recommended as the families for high accumulation of total triterpenoid, total polyphenol, and total flavonoid, respectively. In contrast, the families in cluster 4 showed poor performance in all measured metabolites. Seven superior families (GXJZS7#、GZSQ12#、GXLS26#、HNYS2#、AHQLF13#、SCMC31# and GXJZS1#) of C. paliurus were preliminary selected for the accumulation of target secondary metabolites using entropy method. Within the seven superior families, all the trees were further assessed, and eleven superior individuals were selected. Conclusion There are significant variations in growth and leaf secondary metabolites among the tested germplasm resources, showing a great potential for the selecting and breeding of C. paliurus. Based on the comprehensive assessment, seven superior families and eleven excellent individuals are selected for further test and future application.
2022, 35(5): 52-62.
doi: 10.13275/j.cnki.lykxyj.2022.005.006
Abstract:
Objective To analyze the phenotypic variation of X. sorbifolium, and provide useful information for genetic improvement. Method Thirty-five phenotypic traits among 37 germplasms were analyzed by variance analysis, principal component analysis (PCA), and cluster analysis. Result Large variation and rich phenotypic diversity were found among and within germplasms of X. sorbifolium. The average coefficient of variation for 35 traits of 37 germplasm resources was 25.49%, and the variation range was12.80% to 63.25%. The variation of branch traits was the largest (45.51%) , followed by inflorescence traits (31.01%) , fruit traits (24.67%), flower traits (24.35%), seed traits (21.82%), and leaf traits (21.45%). The mean phenotypic differentiation coefficient was 80.52%, indicating that the variation among germplasm resources was the main source of phenotypic variation. The cumulative contribution rate of the first nine main principal components reached 80.333%. The 37 germplasms were classified into two main groups and six subgroups according to their characteristics by Ward’s method and reasonable utilization of each subgroup were suggested. Conclusion The genetic variation of phenotypic traits of X. sorbifolium is abundant, among which the variation range of inflorescence, fruit and flower traits is larger than that of leaf and seed. It provides useful information for the genetic improvement, preservation, and evaluation of X. sorbifolium germplasms.
2022, 35(5): 63-70.
doi: 10.13275/j.cnki.lykxyj.2022.005.007
Abstract:
Objective To provide insights into carrying out ecological regulation of new mixed forest, the physiological adaptation mechanism of Dendrolimus houi Lajonquiere to different host plants was analyzed based on the effects of different host plants on the growth, reproduction, detoxification enzyme and digestive enzyme activities of D. houi. Methods The developmental duration of the larvae and pupae as well as the fecundity of adult of D. houi were measured through indoor rearing in hots plants of Cryptomeria fortunei Hooibrenk, Platycladus orientalis (L.) Franco, Cupressus funebris Endl., Pinus yunnanensis Franch. and Pinus massoniana Lamb. The activities of detoxification enzymes (i. e. glutathione S-transferases (GSTs), cytochrome P450 (CYP450), and carboxylesterase (CarE)) and digestive enzymes (i. e. protease, amylase (AMS), and lipase (LPS)) in the 5th instar larvae of D. houi feeding on different host plants were also assayed. Results D. houi larvae feeding on C. fortunei, C. funebris, P. orientalis and P. yunnanensis had a complete life cycle, while the larvae feeding on P. massoniana only survived to the 5th instar and did not have a complete life cycle. At the same time, the larvae and pupae of D. houi feeding on C. fortunei and C. funebris had shorter developmental duration, heavier female pupae and more fecundity of adult compared with other host plants. The activities of GSTs and CYP450 in the 5th instar larvae of D. houi feeding on C. fortunei and C. funebris were significantly higher than those feeding on P. yunnanensis, P. orientalis and P. massoniana (P<0.05). Among the three digestive enzymes, the activities of protease in larvae of D. houi feeding on C. fortunei and C. funebris were relatively high. Conclusion Dendrolimus houi has better adaptability to Cryptomeria fortunei and Cupressus funebris than the other host plants, and detoxification enzymes and proteases within D. houi may be the key factors which affect their adaptability to Cryptomeria fortunei and Cupressus funebris.
2022, 35(5): 71-80.
doi: 10.13275/j.cnki.lykxyj.2022.005.008
Abstract:
Objective To screen the hormone proportion suitable for callus differentiation of Litsea cubeba and clarify its tolerance to antibiotics, and preliminarily establish the genetic transformation system of L. cubeba. Method The effects of different hormone concentrations on adventitious bud induction and adventitious bud rooting of L. cubeba callus were studied. The critical screening concentrations of hygromycin and cefotaxime were discussed, and the foreign gene was introduced into L.cubeba callus by Agrobacterium mediated method. Result The optimum medium for inducing adventitious bud differentiation of callus was MS + 2.0 mg·L−1 6-BA + 0.01 mg·L−1 IBA + 0.05 mg·L−1 TDZ, and the differentiation rate was 16.67%～36.67%; The optimum medium for adventitious bud rooting was 1/2MS + 0.5 mg·L−1 IAA, and the rooting rate was 97.33%. The initial concentration of hygromycin for resistant callus screening was 5 mg·L−1 (about 7~10 days), and then the critical screening culture was carried out by gradually increasing the hygromycin screening concentration to 30 mg·L−1. the optimum concentration of cephalosporin was 300 mg·L−1. Finally, foreign gene was transferred into the callus by Agrobacterium mediated method, and PCR primers were designed for identification. A total of 16 resistant seedlings contained the target band, indicating that the target gene had been inserted into the L. cubeba genome, with a transformation rate of 0.67%. In addition, our research group obtained the resistant calli of multiple genes through this method. Southern detection showed that the target fragment had been inserted into the calli of L. cubeba. Conclusion The regeneration and genetic transformation system of L. cubeba has been preliminarily established, and the resistant calli of multiple genes have been obtained, which provides technical support for further gene function research and genetic improvement. The next step is to optimize the genetic transformation system and improve its transformation efficiency.
2022, 35(5): 81-88.
doi: 10.13275/j.cnki.lykxyj.2022.005.009
Abstract:
Objective To provide a typical reference in the aspect of height-to-diameter ratio of broad-leaved trees for the sustainable management of artificial broad-leaved forest, semi-natural broad-leaved forest and natural broad-leaved forest in mid-subtropical zone, the relationship between tree height-to-diameter ratio and DBH and tree height were revealed in each stratum of typical natural broad-leaved forests. Method In Jian’ou Wanmulin Provincial Nature Reserve, 50 m × 50 m plots were set up in 5 most typical natural broad-leaved forest in mid-subtropical zone respectively. Spearman rank correlation coefficient was used to analyze the correlation between tree height-to-diameter ratio and DBH and tree height in each stratum, and exponential function and hyperbola equation were chosen to fit the relationship between height-to-diameter ratio and DBH in each stratum. Results The variation range of the average value of the height-to-diameter ratio in each stratum was not large. The average height-to-diameter ratio of the stand in the 5 sample plots was 103.1. The mean height-to-diameter ratio in stratum Ⅲ(112.7) was the largest, followed by stratum Ⅱ (89.0) and stratum Ⅰ(66.9), as well as in the minimum and maximum values. The height-to-diameter ratio of each stratum showed a significant negative correlation with DHB and the correlation coefficient was high. The absolute value of correlation coefficient was the highest in stratum Ⅰ(0.896～0.961) and stratum Ⅱ(0.912～0.971), the middle in the stand(0.613～0.749), and the lowest in stratum Ⅲ(0.415～0.596).The relationship between tree height-to-diameter ratio and tree height in each stratum was complex and the absolute value of correlation coefficient was low (< 0.480). The stand showed extremely negative correlation, but the absolute value of correlation coefficient was low (0.283～0.458). The R2 of the tree height-to-diameter ratio and DBH in stratum Ⅰ and stratum Ⅱ fitted by exponential function were 0.852～0.906 and 0.830～0.914, respectively, while the R2 of the stand and stratum Ⅲ were 0.465～0.575 and 0.202～0.399, respectively. The R2 of the height-to-diameter ratio and DBH in stratum Ⅰ and stratum Ⅱ fitted by hyperbolic curve were 0.874～0.937 and 0.856～0.968, respectively, while the R2 of the stand and stratum Ⅲ were 0.387～0.536 and 0.186～0.350, respectively. Exponential function fitting stand and stratum Ⅰ relationship of DBH than height-to-diameter ratio of R2 was relatively high, and RMSE and AMR was relatively small. hyperbola from fitting relationship of DBH than height-to-diameter ratio stratum Ⅰ and stratum Ⅱ fitted by hyperbola equation had relatively high R2 and small RMSE and AMR was values. Conclusion The tree height/diameter ratio of typical natural broad-leaved forest in mid-subtropical zone varies with the stratum. The tree height/diameter ratio in the same stratum also varies with DBH. The height-to-diameter ratio and DBH in each stratum shows a very significant negative correlation and the correlation coefficient is high, and the curve fitting of the relationship is significant. Hyperbolic function can well describe the relationship between height-to-diameter ratio and DBH in the stratum Ⅰ and stratum Ⅱ, while exponential function is more suitable to describe the relationship between height-to-diameter ratio and DBH in the stand and the stratum Ⅲ. The relationship between tree height-to-diameter ratio and tree height in each stratum is complex and the correlation coefficient is low. In the typical natural broad-leaved forest of the mid-subtropical zone, the characteristics of tree height/diameter ratio can be expressed by the relationship curve between tree height to diameter and DBH of each stratum.
2022, 35(5): 89-96.
doi: 10.13275/j.cnki.lykxyj.2022.005.010
Abstract:
Objective To study the soil infiltration characteristics of four Caragana korshinskii forests in the loess hilly area of Inner Mongolia for providing a reference for reasonable local forest planting and vegetation restoration and construction. Method The cutting ring knife was used for sampling and analyzing soil physical and chemical properties in Caragana korshinskii and Populus davidiana × Caragana korshinskii, Armeniaca sibirica × Caragana korshinskii, Pinus tabuliformis × Caragana korshinskii forests. The single ring soil column method was used to observe the undisturbed soil water infiltration, and the correlation between infiltration characteristics and soil physical and chemical properties was analyzed. Results The initial infiltration rate, steady infiltration rate, 5 h cumulative infiltration amount, and the rate of wetting front of the four forests were the largest in A. sibirica × C. korshinskii forest (8.60 mm · min−1, 1.05 mm · min−1, 279.83 mm, 2.5 mm · min−1), followed by P. davidiana × C. korshinskii (5.6 mm · min−1, 0.76 mm · min−1, 255.65 mm, 2.2 mm · min−1), P. tabuliformis × C. korshinskii (4.80 mm · min−1, 0.73 mm · min−1, 243.03 mm, 2.0 mm · min−1), C. korshinskii（3.16 mm·min−1, 0.53 mm·min−1, 178.64 mm, 3.4 mm·min−1）. After infiltration, the soil saturated moisture content and field water holding capacity were shown as follows: A. sibirica × C. korshinskii > P. davidiana × C. korshinskii, P. tabuliformis × C. korshinskii > C. korshinskii. Soil bulk density and porosity were the main factors affecting the infiltration capacity and water status of the four woodlands. Conclusion Comparing with other forests, A. sibirica × C. korshinskii has better regulation and water conservation function, and can effectively reduce surface runoff and soil erosion.
2022, 35(5): 97-102.
doi: 10.13275/j.cnki.lykxyj.2022.005.011
Abstract:
Objective Stand density is an important index to reflect the number and competition in a stand. It plays a critical role in stand growth models. It is of great significance to analyze the application value of stand density index in stand volume growth model for accurate prediction. Method Based on the 28 years continuous observation data of the spacing trials of Chinese fir (Cunninghamia lanceolata) plantation in Shaowu, Fujian Province, the annual growth model of stand volume of Chinese fir including five different density indices respectively were developed based on the variable rate method, as well as the model without stand density index. Result The R2 values of the models including density indices were all larger than 0.979, and the model performance was higher than that of the model without density index. Among the five models including stand density indices, the model including living number of trees per ha (N) had the largest value of R2, followed by the model with RS density. However, the two models are not feasible because of the parameter estimates of stand density index were not significant. The R2 values of all models from high to low were: stand volume model including N (0.979 9), relative spacing RS (0.979 9), stand density index SDI (0.979 4), dominant high nutrient area ratio Z (0.979 3), Nilson density index model (0.979 0) and without density index (0.972 8). Conclusion Accounting for significance of the parameter estimate, the model with stand density index SDI performed the best in the stand volume model of Chinese fir. In addition, stand volume in stands of planting density (1 667 ～ 3 333 trees·hm−2) was larger than the denser stands (5 000 ～ 10 000 trees·hm−2).
2022, 35(5): 103-112.
doi: 10.13275/j.cnki.lykxyj.2022.005.012
Abstract:
Objective The genetic diversity of leaf phenotypic traits of 701 Eucommia ulmoides germplasm resources was investigated to provide theoretical support and materials for the breeding, development and utilization of Eucommia ulmoides. Methods Fourteen phenotypic traits of Eucommia ulmoides leaves were determined. Correlation analysis, principal component analysis and cluster analysis were used to investigate the genetic diversity of leaf phenotypic traits among different germplasm. Results There were significant differences among 14 phenotypic traits of Eucommia ulmoides leaves. The coefficient of variation of leaf area was the largest (20.68%), and the coefficient of variation of chlorophyll reference value was the smallest (4.57%). The genetic diversity index of each phenotypic trait ranged from 1.90 to 2.09, and the genetic diversity index of leaf length and petiole length was the highest with 2.09.There were 26 pairs of leaf phenotypic traits that are significantly positively correlated, and 19 pairs that are significantly negatively correlated (P<0.01). There were extremely significant positive correlations among the five traits of leaf length, leaf width, leaf area, leaf circumference and petiole length (P<0.01). The cumulative contribution rate of 6 principal components extracted by principal component analysis was 89.211%. Based on 14 phenotypic traits, 701 Eucommia ulmoides germplasm were divided into 4 categories. There were significant differences in leaf phenotypic traits among various groups. Conclusion The leaf phenotypic traits of Eucommia ulmoides germplasm resources show rich diversity, and six traits are selected as important indicators for evaluating the resources of Eucommia ulmoides germplasm resources, including leaf area, Specific leaf fresh weight, green component of leaf, chlorophyll reference value, length to width ratio of leaf, and internode length. It provides an excellent germplasm basis for the selection and comprehensive utilization of Eucommia ulmoides varieties.
2022, 35(5): 113-122.
doi: 10.13275/j.cnki.lykxyj.2022.005.013
Abstract:
Objective To excavate high-quality germplasm resources and provide solid foundation for the selection and breeding of superior and new varieties in the future, it is necessary to analyze the phenotypic traits variation pattern of E. mollis. Method 100 10-year-old seedlings were selected from the provincial nature reserve of E. mollis located in Yicheng, Shanxi Province. A trait list of E. mollis was compiled according to the quantitative classification method. Various methods were used to reveal the variation pattern of E. mollis germplasm resources. Results The phenotypic variation of E. mollis ranged from 9.72% to 37.66%, with an average coefficient variation value of 22.26%. H’ of the phenotypic traits varied between 1.056 and 2.213. Correlation analysis showed that phenotypic traits of a single organ correlated significantly with each other, phenotypic traits from different organs showed no correlation. However, the leaf length showed significant correlation with fruit traits. PCA result showed that the first 7 principal components contributed 79.053% to the total variation, and the contribution rate of each trait was scattered. Cluster analysis based on phenotypic traits of fruit showed that all the individuals can be divided into 3 groups at the coefficient distance of 10 and differences among these 3 groups were significant. PCA analysis of phenotypic traits of fruit indicated that yield and kernel related traits can be chosen as the primary target in future E. mollis breeding. Therefore, individual 10, 17, 33, 37, 56 and 74 were chosen as the primary material for future breeding of superior and new varieties of E. mollis. Conclusion The phenotypic traits variation pattern of E. mollis plantation in Shanxi Province was high, different materials can be chosen based on various breeding targets.
2022, 35(5): 123-133.
doi: 10.13275/j.cnki.lykxyj.2022.005.014
Abstract:
Objective To verify the formation mechanism of the alpine treeline and explore the limiting factors of the upper limit of tree distribution. Methods In the low altitude coniferous and broad-leaved mixed forest (3500 m), suitable altitude area (3900 m) and high altitude treeline transition zone (4300 m) in Sygera Mountain, the contents of non-structural carbohydrates and C, N, and P in leaves, branches, stems and roots of Abies georgei var. smithii as well as were measured both in the growing season (early July) and non-growing season (end of November). Results The results showed that the non-structural carbohydrate sources and sinks of Abies georgei var. smithii were stable in different growing seasons, and there was no insufficient carbon supply. There were little effects of altitude on the non-structural carbohydrates and their components in Abies georgei var. smithii . There were significant differences in NSC content among organs, and the physiological activities and functions of leaves, branches, trunks, and roots were significantly different in different growing seasons. In the non-growing season, non-structural carbohydrates and their components were significantly higher than those in the growing season. In the non-growing season, higher soluble sugars and NSC contents enabled the vegetation to resist cold temperature and other harsh conditions. The content of NSC in Abies georgei var. smithii increased with the increase of altitude, which supported the hypothesis “growth limitation” . Conclusion The growth of Abies georgei var. smithii is more restricted by plant nutrients than by carbon.
2022, 35(5): 134-145.
doi: 10.13275/j.cnki.lykxyj.2022.005.015
Abstract:
Objective To understand the mixed litters decomposition characteristics of Pinus massoniana and native broad-leaved trees, and the relationship between the mass loss rate of mixed litter with the species and proportion of broad-leaved litter. Method Based on the leaf litter of Pinus massoniana Lamb.(P), Cinnamomum camphora Presl.(C), Sassafras tzumu Hemsl.(S) and Toona sinensis Roem.(T), we conducted a two-year field needle-width mixed decomposition experiment of litter bags to study the mass loss of the pure litter of the above four tree species and their mixed litter, i.e., combining needles of one conifer with leaves of one, two or three broad-leaved species (i.e., PC, PS, PT, PSC, PST, PCT and PSCT, respectively), as well as including various ratios of these mixed litters in each treatment. There was a total of 35 treatments, including 31 mixed and 4 pure litter treatments. Result After two years of decomposition, the combinations of PT, PC, PCT, PST and PSCT had higher mass loss rates of than PS and PSC. The mass loss rate of leaf litters generally showed a synergistic effect and it increased from the 6th to 18th month, and then declined thereafter. It was the highest (67.74%) at the 18th month of decomposition. Compared with other mixed litters, the mass loss rate of PT64, PCT721 and PSCT7111 showed a strong synergistic effect in 4 incubation periods. The results of regression analysis showed that the decomposition coefficient k and mixing effect were negatively correlated with the initial contents of total phenolic, lignin, cellulose, the ratios of C/N, C/P, lignin/N, and lignin/P. In contrast, they were positively correlated with the initial contents of N and P. Conclusion Our results show that mixed litters with 30%-40% broad-leaved species, especially with the litter of T. sinensis, may benefit the litter mass loss of P. massoniana and promote the nutrient return to forest soils.
Sapling Stem Stoichiometry of Dominant Species in Three Types of Tropical Forests in Southern Yunnan
2022, 35(5): 146-155.
doi: 10.13275/j.cnki.lykxyj.2022.005.016
Abstract:
Objective The aim this study was to explore the distribution patterns and limitation of nutrient elements in subtropical forest species in southern Yunnan, for revealing the adaptive mechanism of tree species under a changing environment. Method The dominant species in three types of tropical forests, i.e., tropical seasonal rain forests, tropical montane rain forests and montane moist evergreen broad-leaved forests, were sampled in southern Yunnan to analyze C, N, P and their stoichiometric ratios in sapling stems. Result 1) The total C of sapling stems of dominant species in the three types of tropical forests generally increased, but total N and P decreased with increasing elevation. 2) The ratios of stem C:N and C:P in montane moist evergreen broad-leaved forests were relatively high compared to other two types of forests. The ratio of stem N:P both in tropical seasonal rain forests and tropical montane rain forests were less than 14, while this value in montane moist evergreen broad-leaved forests was higher than 16. 3) The stem C and N of dominant species in upper canopy were smaller than lower canopy. However, total P contents in upper canopy was higher than those in lower canopy. The value of N:P in upper canopy was less than 14, whereas it was higher than 16 in lower canopy. These results suggested that the growth of dominant species in upper canopy was mainly limited by N. 4) The results of Redundancy analysis revealed that elevation and community had a great effect on C, N and P contents and their stoichiometric ratios in sapling stems of dominant species. Conclusion Montane moist evergreen broad-leaved forest has a relatively high nutrient efficiency, and the forest ecosystems in southern Yunnan are mainly limited by N and P contents. The difference of ecological stoichiometric characteristics in trees under different environments can reveal the coping mechanisms of species adaptating to changing environments.
2022, 35(5): 156-163.
doi: 10.13275/j.cnki.lykxyj.2022.005.017
Abstract:
Objective To explore the responses of soil active organic carbon pool and CPMI to different control measures in rocky desertification area and provide the scientific basis for rational land use and rocky desertification ecological management in karst area. Method Three typical measures for controlling rocky desertification in karst including Nested ladder(NL), Fish scale pit(FSP), and terrace(TR) were compared with CK (natural slope soils) . The response of soil active carbon and carbon pool management index under different control measures was studied. Result The soil active organic carbon content and storage under different rocky desertification control measures showed a trend of the highest FSP, followed by the NL, and the lowest TR. The contents of EOC, DOC and pool storage showed that FSP were significantly higher than the other measures. The CPMI in FSP were all higher than NL and TR. The CPMI showed that the fish scale pit measure was greater than the other two rocky desertification control measures. The control measures improved the quality of the topsoil in the karst area. Conclusion This study suggests that different rocky desertification control can significantly affect the active organic carbon in karst. FSP is more beneficial to the active SOC fraction accumulation and the quality of carbon pool than other measures. FSP can be used as a priority measure for the ecological restoration of karst rocky desertification.
2022, 35(5): 164-171.
doi: 10.13275/j.cnki.lykxyj.2022.005.018
Abstract:
Objective To study the nutrient resorption characteristics of Pinus thunbergii under different densities (high density: 1150 plants·hm−2, medium density: 535 plants·hm−2, low density: 285 plants·hm−2)and the effects of leaves and soil nutrient contents and stoichiometric characteristics on the resorption efficiency, in order to provide a scientific basis for the rational management of Pinus thunbergii. Method Taking Pinus thunbergii in the shelter forest of Muping coastal zone in Yantai as the research object, by collecting mature leaves, senescing leaves and soil samples of 0-20 cm under forest of Pinus thunbergii with different stand densities, the carbon (C), nitrogen (N), phosphorus (P) of leaves and soil, nitrate nitrogen (NO3 −-N), ammonium nitrogen (NH4 +-N), available phosphorus (AP) contents were determined, and researched the nutrient resorption characteristics of Pinus thunbergii at different densities, and analyzed the resorption of Pinus thunbergii leaves under different densities characteristics, leaves and soil nutrient contents, stoichiometric characteristics and their correlations. Result （1）The average nitrogen resorption rate (NRE) and phosphorus resorption rate (PRE) were 52.44% and 48.53% in Muping coastal shelter forest. The NRE was similar as the average level of global coniferous forests, and the PRE was lower than the average level of global coniferous forests. Under the three densities, the growth and development of Pinus thunbergii were more restricted by N, which was consistent with the “relative resorption hypothesis”. （2）In the medium density area, the nutrient contents and resorption rates of mature leaves were the highest, and the NRE was significantly higher than high stand densities. The contents of C, N and P in mature leaves of Pinus thunbergii increased with the increase of density and then decreased, and the contents of senescing leaves were not significantly different among different densities. At medium density, C:N of mature leaves was significantly higher than that of low and high density; C:P of senescing leaves was significantly lower at low density. (3) Soil AP content was significantly higher in low-density forests; soil TN was significantly higher in medium-density forests; soil TP in high density stands was significantly lower than that in medium and low density stands. Soil C:N and C:P were significantly higher at high density, and at medium density, N:P was significantly higher than low and high density. (4) Nutrients and stoichiometric indicators of senescing leaves had more significant effects on nutrient resorption, and the responses of NRE and PRE to leaf and soil nutrients and their stoichiometric characteristics were different under different densities. Conclusion In our experimental condition, Pinus thunbergii with medium density can relatively improve the nutrient utilization efficiency, which is more conducive to adapting to the N limitation in this area.
2022, 35(5): 172-179.
doi: 10.13275/j.cnki.lykxyj.2022.005.019
Abstract:
Objective To improve regional site index model, the site index model with the random effects of site factors was developed. Method Based on the 360 samples with dominant height-age of Chinese fir in the hilly and plain area of Hunan Province, the quantification method I was used to select the site factors affecting the dominant height growth (P<0.05). The 8 commonly used models were used to develop the basic site index model, as well as the models considering the random effects of site factors and their combinations. The evaluation statistics including AIC, BIC, Log-likelihood and R2 were used to select the optimal random effect model. In addition, K-means clustering was used to divide site type groups for model applications. Results 1) The site factors including altitude, slope, aspect and soil type had significant impact on dominant height growth based on the quantitative method I. And soil type was the most important factor, following by altitude, slope aspect, and Slope. 2) The fitting accuracy of the 8 candidate basic models was low (R2=0.4243~0.5644). M4 (R2=0.5644) was selected the best basic model for developing the polymorphic site index curve. 3) Considering the influence of the site effect on the site index, the nonlinear mixed effects models with different site factors and their combination of random effects were developed. The mixed effects model with the random effects of site type performed the best (R2=0.8089). 4) The site types were divided into 11 site groups. The mixed model containing the site type groups improved the modeling accuracy (R2=0.8117). Conclusion The site index model with site mixed effect can significantly improve the site modeling accuracy of regional complex site types, and provide a reference and basis for regional forest site quality evaluation.
2022, 35(5): 180-187.
doi: 10.13275/j.cnki.lykxyj.2022.005.020
Abstract:
Objective To reveal the response of suitable distribution of Prunus pedunculata to climate change. Method Based on the field investigation, MaxEnt and ArcGIS software were used to predict the change of suitable distribution area of Prunus pedunculata in the future climate scenario. Results The suitable distribution region of Prunus pedunculata was mainly concentrated in China, Mongolia and Russia, and the distribution area located in 97.23°-122.62° E and 35.49°-54.91° N. Under the reference climate (1970−2000) scenario, the medium and high suitable distribution area are mainly located in China. Seasonality Precipitation (bio15, Coefficient of Variation) was the climate variable with the highest score in the prediction process. Under the four future (2021−2100) climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) , the geometric center of the suitable distribution area would move to the northwest. In the scenario of increased emissions, the average migration rate of geometric centers increased. Conclusion Seasonality Precipitation (bio15) is the most critical variable to limit the distribution of Prunus pedunculata. The suitable distribution area of Prunus pedunculata trends to migrate to the northwest. Under the high emission scenario, the change of the suitable distribution region is more active than the low emission scenario.
2022, 35(5): 188-195.
doi: 10.13275/j.cnki.lykxyj.2022.005.021
Abstract:
Objective To understand the relationship between water and carbon metabolism and growth and fruiting of branches at different positions in the crown of Hippophae rhamnoides for providing a certain theoretical basis for the formulation of cultivation technical measures for Hippophae rhamnoides tree shape culture. Method According to the two-year-old branches in the upper, middle and lower crown of Hippophae rhamnoides, water status, photosynthesis, non-structural carbohydrate (NSC) content, branch and leaf growth, fruiting traits and fruit nutrients were compared. Result The results showed that there was no significant difference in the pre-dawn water potential of branches in different parts of the crown, and the water potential of the bottom branches at midday was significantly higher than that of the upper and middle branches. The percentage loss of conductivity (PLC) of the middle branch in pre-dawn was significantly lower than that of upper and lower branches, and the PLC of the bottom branch at midday was significantly higher than that of top and middle branches. The stem and leaf area specific hydraulic conductivity of upper branches was significantly higher than that of middle and lower branches. The net photosynthetic rate in the top branch was the largest, followed by middle branch and bottom branch. NSC content in xylem of middle branches was significantly higher than that of upper branches, but there was no significant difference between the upper and lower branches, as well as between the middle and lower branches. There was no significant difference in NSC content in phloem among branches, and the NSC content in leaves of upper and middle branches was significantly higher than that of lower branches. The longitudinal and transverse diameter of flower buds, the proportion of pure flower buds, the germination rate, the number of new shoots, the basal diameter of new shoots, the leaf area and the specific leaf mass of the bottom branches were significantly lower than those of the upper and middle branches. The longitudinal and transverse diameter of fruit, fruit setting rate and soluble solid content of the bottom branches were both lower than those of the upper and middle branches. The branch length and base diameter of the upper branches are significantly higher than that of the middle branch. The fruit quality and fruit vertical and horizontal diameter of the middle branch were significantly higher than those of the upper branch. There was no significant difference in the contents of flavonoids, vitamin C and titratable acid among different branches. Conclusion The lower branches are greatly affected by shading, which significantly restricts the uptake and growth of photosynthetic products, and affects their fruiting traits. The upper branches are dominant in growth, and the middle branches are dominant in fruiting traits. Therefore, the tree-shaped cultivation of Hippophae rhamnoides should take full account of its light conditions, and timely remove the branches in the lower light area. At the same time, we should pay attention to the balance between nutritional growth and reproductive growth, and making full use of the upper and middle branches of the crownfor improving the yield and quality of Hippophae rhamnoides.
2022, 35(5): 196-205.
doi: 10.13275/j.cnki.lykxyj.2022.005.022
Abstract:
Objecive To improve the antibacterial activity of its sterile filtrate against the pathogen of pine shoot blight and obtain the high-efficiency antibacterial fermentation medium formula of Trichoderma songyi M75, response surface method was used to optimize the liquid fermentation culture conditions of T. songyi M75 . Method Plackett-Burman experiment, the steepest ascent method, and response surface method were used to optimize the fermentation medium of T. songyi M75, and the experiment data were analyzed using Design Expert 11.0. Result The three main influential factors were glucose, temperature and speed and the optimal fermentation culture concentrations conditions were: glucose 2.75%, tryptone 1.2%, zinc sulfate 0.2%, potato juice 1000 mL, temperature 31.0 ℃, rotation speed 195 r·min−1, inoculation volume 5%, liquid volume 180 mL, fermentation culture 5 d. Conclusion This study greatly improves the antibacterial activity and obtains the optimal culture conditions, which provides an effective basis for the follow-up study of T. songyi strains.
Subvmission Guidelines
Peer Review
Reviewer Online
Office Work
Email alert
RSS