Primula Hance(Gesneriaceae)is a group that has attracted much attention in recent years. Its intricate species diversity and its endemic distribution among species have aroused great interest among taxonomists and botany researchers. Except for a few species, like Primulina eburnea (Hance)Y. Z. Wang, most species have a very narrow distribution range, which belong to narrow distribution species or endemic species. In order to reveal the effects of the pollination biology and breeding system of P. eburnea on its reproductive process and colonization ability, we systematically studied the flowering phenology, the pollen and stigma viability, the species and visiting behavior of flower visiting insects, the pollen ovule ratio, the OCI index and the seed setting rate of manipulated pollination of P. eburnea. Besides, we explored whether its reproductive processes such as pollination had a positive effect on the spread of P. eburnea. The results showed that the natural flowering stage of P. eburnea was from March to May, and the entire flowering stage was about 45 d. Its full flowering stage was about 20 d, and the single flower flowering stage was 6-8 d. Pollens had the strongest viability 1-2 d after flowering, stigma did not have receptivity before flowering. The pollen ovule ratio was 537, and the hybridization index was 5. Bagged and emasculation could not bear fruit, indicating that this species did not have apomixis. Compared with natural pollination, the seed setting rate of hand self-pollination was slightly lower, and the seed setting rate of hand xenogamy was slightly higher, indicating self-compatibility. The main pollinators of P. eburnea were Anthophora florea and Bombus sp. Therefore, higher nectar volume, larger pollen amount and stronger pollen viability of P. eburnea were obviously beneficial for it to complete the entire process of pollination and reproduction. This result was obviously conducive to the colonization of P. eburnea and then widely spread in the karst areas of South China to Southwest China.]]> 2021/6/4 11:38:27 1, HUANG Shilian^3,4, HONG Xin^1,2,5, WEN Fang^2,3*]]> WANG Ziqi¹, HUANG Shilian^3,4, HONG Xin^1,2,5, WEN Fang^2,3* 10true Kalopanax septemlobus and Celtis sinensis increased, while the important values of Zanthoxylum armatum, Campylotropis macrocarpa and Pyracantha fortuneana decreased, and the mortality rate was higher.(2)There was no significant differences in species diversity indexes between different years. Species richness and Margalef richness index increased first and then decreased. Shannon-Wiener diversity index was basically stable, and uniformity index decreased first and then increased, the differences were significant between 2013 and 2019.(3)The distribution of diameter class and tree height showed “inverted J” and “left partial normal” distribution, and there was no significant differences in different years. The number of individuals of large diameter class(DBH≥10 cm)increased, but the number of tall trees(H≥9 m)decreased. In the shrub layer, the number of individuals of Pyracantha fortuneana, Campylotropis macrocarpa and Rhamnus rosthornii at 0≤H<3 m and 0≤DBH<2.5 cm, decreased, while the number of individual tree species such as Kalopanax septemlobus and Celtis sinensis increased. The natural succession process of karst secondary forest is slow and complex, and the hierarchical structure is not obvious. The community is in the middle and early stage of succession, and the community regeneration is good, which will further develop in the direction of arbor dominance.]]> 2021/6/4 11:38:27 1, RONG Li^1*, WANG Mengjie¹, YE Tianmu¹, WANG Qi²]]> LI Tingting¹, RONG Li^1*, WANG Mengjie¹, YE Tianmu¹, WANG Qi² 9true χ² test, Pearson correlation coefficient test, Spearman rank correlation coefficient test and principal component analysis( PCA ). The results were as follows:(1)Overall interspecific association were significant positive correlations in tree layer, non-significant positive associations in shrub layer and significant positive associations in community, indicating that the plant community in tiankeng forests was at a stable stage.(2)The χ2 test, Pearson correlation coefficient test and Spearman rank correlation coefficient test found that there was a difference between positive and negative correlation in tree layer and shrub layer. Many positive correlation species pairs existed in tree layer and many negative correlation species pairs existed in shrub layer, but both of them were more significant correlation species pairs than non-significantanes, which indicates that the stability of community composition in tree layer was higher than shrub layer, and there was a strong competition and cooperation between species pairs in tree layer, a strong competition and repulsion between species pairs in shrub layer, and a close interspecific association in community.(3)According to the results of PCA, the 24 main woody species were divided into four ecological species groups. The tiankeng forests community distribution was in a circle distribution pattern from the bottom to the top of the tiankeng topography, which was affected by environmental differences and species characteristics. In conclusion, these results suggest that the close interspecific association may be one of the maintenance mechanisms of tiankeng forest species diversity, while the self-regulation of interspecific association within the community and convergence adaptation of species to habitat heterogeneity are the basis for maintaining the stability of the community.]]> 2021/6/4 11:38:27 1,2, YU Yanmei^1,2, AN Xiaofei^1,2, YU Linlan^1,2, XUE Yuegui^1,2*]]> HUANG Linjuan^1,2, YU Yanmei^1,2, AN Xiaofei^1,2, YU Linlan^1,2, XUE Yuegui^1,2* 8true Vitex negundo and Bauhinia championii, two common species in typical karst mountains of this area as control. The results were as follows:(1)There were considerable intraspecific variations for the eleven leaf function traits, and threr were significant differences in leaf function traits except for intercellular carbon dioxide concentration(C_i)and water use efficiency(WUE).(2)There was highly significant negative correlation between specific leaf area(SLA)and leaf dry matter content(LDMC), and leaf tissue density(LTD); However, net photosynthetic rate(P_n)was very significant positive related to stomatal conductance(G_s)and transpiration rate(T_r); Relative chlorophyll content significantly negatively correlated with P_n, and significantly negatively with C_i and T_r remarkably.(3)Vitis heyneana, Morus wittiorum, and Vitex negundo were quick investment-return species on the leaf economics spectrum, and they tend to choose a survival strategy of strong photosynthesis and large SLA, but short life span; However, Citrus limon, Clausena excavata, Eriobotrya japonica and Bauhinia championii were slow investment-return species on the leaf economics spectrum, and they tend to choose a survival strategy of weak photosynthesis, small SLA, and long life span; The leaf function traits occurred divergent differentiation between Eriobotrya japonica and Bauhinia championii, and the former had higher WUE, while the latter had higher LDMC. The results proved that the five dominant woody economic plants took different adaptation strategies to habitats by trade-off among leaf functional traits. The results had important theoretical significance to the vegetation restoration and reconstruction of karst degraded ecosystem.]]> 2021/6/4 11:38:27 *, SHEN Wenhui, HE Feng, LU Guodao]]> PANG Shilong, OU Zhiyang^*, SHEN Wenhui, HE Feng, LU Guodao 7true K value of erodibility was the lowest.(2)The soil organic carbon, total nitrogen, and total phosphorus contents in the five sample plots were 20.78-56.28 g·kg^-1, 1.17-2.14 g·kg^-1 and 0.41-0.97 g·kg^-1, respectively. The composition of organic carbon and total nitrogen in aggregates of the nil rocky desertification sample plot were the highest, and the variation of total phosphorus content were not obvious in the five environments. The ranges of C/N, C/P and N/P of five environmental aggregates were 11.50-28.60, 25.19-121.75 and 1.65-4.69, respectively. The C/N, C/P and N/P of the aggregate in the nil rocky desertification sample plot were significantly highest. Averaged C/N values in the small-size aggregates were higher than in aggregates of other sizes, while the maximum values C/P and N/P were >2mm and 0.25-2 mm.(3)There was a significant positive correlation between organic carbon and C/N, C/P, and a significant negative correlation between total phosphorus and C/P, N/P(P<0.01). The overall trend of the variation level of soil aggregate stoichiometry was C/P>C/N>N/P. The stability and the contents of organic carbon and total nitrogen in aggregates with different particle sizes decreased firstly and increased from nil rocky desertification to severe rocky desertification in the study area. The soil structure of nil rocky desertification is good; what is more, nitrogen in the aggregate is the major factor affecting the soil quality in the degraded ecosystem.]]> 2021/6/4 11:38:27 *, CHEN Hai]]> CHEN Jing, ZHU Dayun, CHEN Hu^*, CHEN Hai 6true 2048-D₁₇₃₃ had the best modeling and verification result, and was the best index model for estimating leaf water content of karst plants; For non-karst plants, the spectral index of D₂₃₅₆ / D₁₈₈₅ and(D₂₃₅₆-D₁₈₈₅)/(D₂₃₅₆ + D₁₈₈₅)had similar results, and both of them could be used as the best estimation indexes of leaf water content. This results also showed that, for karst plants, the leaf pubescence had little effect on the construction of inversion model of leaf water content. Generally, the newly constructed optimal spectral index has a better fitting effect on the leaf water content in karst and non-karst areas than the traditional index, and has a good general applicability, which could provide a scientific basis for the accurate assessment of vegetation water state in North Guangxi.]]> 2021/6/4 11:38:27 1, GU Daxing^1*, NI Longkang¹, HE Wen¹, RUAN Yangchun², HUANG Yuqing², WANG Quan³]]> QIN Jiashuang¹, GU Daxing^1*, NI Longkang¹, HE Wen¹, RUAN Yangchun², HUANG Yuqing², WANG Quan³ 5true Cinnamomum camphora, Zenia insignis, Camptotheca acuminata and Acacia confusa which are common in Guangxi rocky desertified region were used as experimental materials. The plate dilution method was used to screen nitrogen-fixing bacteria from rhizosphere soil of rocky desertification native plants. The strains with higher nitrogenase activities were selected and inoculated into experimental seedlings for pot experiment. The results were as follows: Six strains of nitrogen-fixing bacteria from rhizosphere soil were obtained, and the 16S rDNA sequence analysis showed that the tested strains belong to Rhizobium, Sinorhizobium and Flavobacterium. Among them, the nitrogenase activity of three strains of Rhizobium was the highest. Pot experiment showed that inoculating nitrogen fixing bacteria could promote the growth of afforestation seedlings. Plant height, leaf area, leaf dry weight and chlorophyll content increased significantly compared to control. Nitrogen content of Cinnamomum camphora, Zenia insignis, Camptotheca acuminate and Acacia confusa seedlings significantly increased by 28.9%, 53.1%, 37.0% and 31.6%, respectively. Phosphorus contents of Cinnamomum camphora and Acacia confusa was increased significantly by 25.6% and 42.5%, respectively, while the potassium contents of Zenia insignis and Acacia confusa was increased significantly by 57.5% and 49.7%, respectively. The nitrogen-fixing bacterial strains of karst rocky decertified areas in Guangxi have growth promoting effect on local tree seedings used for afforestation. They provide a strong potential for forest restoration through seedling inoculation.]]> 2021/6/4 11:38:27 1, ZHANG Zhongfeng^1*, JIANG Shisong², TANG Jinrong³, ZHOU Longwu¹, TENG Qiumei¹, XU Guangping¹]]> CAO Yanqiang¹, ZHANG Zhongfeng^1*, JIANG Shisong², TANG Jinrong³, ZHOU Longwu¹, TENG Qiumei¹, XU Guangping¹ 4true Loropetalum chinense communities in karst hills of Guilin between different recovery stages of change, the typical sample plots were selected by the concept of space instead of time. Analysis about the inter-specific associations of main species at different restoration stages of the L. chinense communities in karst hills of Guilin was carried out by means of the significance test of the overall association among multi-species, the measurement of χ² statistics and the Spearman rank correlation test. The results were as follows:(1)At the shrub stage, the overall inter-species relationship was no significant negative correlation. From shrub to tree stage, the overall inter-species relationship in the shrub layer was no significant positive correlation while that in the tree layer was no significant negative correlation. While at the small tree stage, the overall inter-species relationships in the shrub layer and tree layer were no significant positive correlation equally. In the process of natural restoration of L. chinense communities, the proportions of positive associative species in the tree layer and shrub layer showed an upward trend equally but was processed at a slow pace.(2)The results of the χ² statistics and the Spearman rank correlation test showed that most species pairs in the tree layer and shrub layer were not significantly correlated. The inter-species association was relatively loose and each species was comparatively independent. The above results indicate that three stages in the L. chinense communities are still in a relatively low stage of community development.]]> 2021/6/4 11:38:27 1,2,3, MA Jiangming^1,2,3*, MO Yanhua^1,2,3, WANG Yongqi^1,2,3, QIN Jiashuang^1,2,3, PAN Xiaomei^1,2,3]]> JIAN Rui^1,2,3, MA Jiangming^1,2,3*, MO Yanhua^1,2,3, WANG Yongqi^1,2,3, QIN Jiashuang^1,2,3, PAN Xiaomei^1,2,3 3true Choerospondias axillaris-Camptotheca acuminata+ Croton tiglium (Association Group A), Ass. Swida wilsoniana-Camptotheca acuminata(Association Group B), Ass. Quercus acutissima-Loropetalum chinense(Association Group C).(2)The species richness, species abundance, basal area, and the importance value for evergreen and deciduous species were different for each community type. Deciduous species were dominant in the tree layer for all three association groups. Shrub layer for Association Group A and Group B were also dominated by deciduous species, while Association Group C was dominated by evergreen species.(3)The species richness, species abundance, basal area and importance value of deciduous species in Association Group A and Group B were greater than evergreen species within the 1-5 cm and 5-10 cm diameter classes. In Association Group C, all indicators were greater for evergreen species than deciduous species for the 1-5 cm and 5-10 cm diameter classes. For the ≥10 cm diameter class, deciduous species were dominant for all indicators in all three association groups except for the species richness in Association Group B.(4)The rock bare rate, soil water content, elevation, aspect, pH, soil organic matter, total nitrogen, available nitrogen, available potassium, canopy openness and human disturbance gradient were the dominant factors affecting the distribution of different types of communities in the study.]]> 2021/6/4 11:38:27 1,2, LIANG Shichu^1,2, YAO Yipeng³, JIANG Yong^1,2*, BAO Han^1,2, NONG Caiwang^1,2, SONG Jing^1,2, HUANG Jia^1,2, GAN Xinmei^1,2]]> LIN Hongling^1,2, LIANG Shichu^1,2, YAO Yipeng³, JIANG Yong^1,2*, BAO Han^1,2, NONG Caiwang^1,2, SONG Jing^1,2, HUANG Jia^1,2, GAN Xinmei^1,2 2true 13C)in plant leaves of three typical aquatic plants under different growth environments, three life forms of aquatic plants including emerging plant(Phragmites australis), emersion plant(Eichhornia crassipes) and submerged plant(Ceratophyllum demersumin) of the Huixian karst wetland were selected as study objects. The differences of carbon isotope compositions of interspecies and different habitat conditions were studied, and the percentage of HCO^-₃ uptaken from water by aquatic photosynthesis was also estimated using the double-meta model. The results were as follows:(1)The foliar δ¹³C of three diffirent plant life forms ranged from -28.47‰～-21.69‰ with an average of -24.83‰. There were significant differences among species, and the sequence of relative value was Ceratophyllum demersum>Eichhornia crassipes>Phragmites australis, and among the three types of plants,Phragmites australis and Ceratophyllum demersum show the lowest and highest δ¹³ C, respectively.(2)For three types of halophytes,δ¹³C showed significantly positive correlations with foliar C, N and P. The δ¹³C was also positively correlated with the contents of organic matter, available nitrogen, total nitrogen, available phosphorus and total phosphorus of sediment. All types of halophytes showed a negative correlation among δ¹³C, C/N, N/P and C/P.(3)The foliar N/P ratio of halophytes was 10.34, indicating a co-limitation by N and P for halophyte growth in the Huixian karst wetland.(4)These results suggested that three halophytes were adapted to environment through a high water use efficiency at the expense of decreased nitrogen use efficiency, and might improve C sequestration by increasing phosphorus use efficiency in the habitat of low water availability.(5)The value of HCO^-₃ carbon sequestration by photosynhesis was 159.60 t·a^-1·km^-2 for Phragmites australis, 10.80 t·a^-1·km^-2 for Eichhornia crassipes, 9.24 t·a^-1·km^-2 for Ceratophyllum demersum, with a mean value of 59.88 t·a^-1·km^-2. Different plant life forms, pathways of carbon fixation in photosynthesis and micro-environment were the important factors on affecting plant foliar δ¹³C in the Huixian karst wetland.]]> 2021/6/4 11:38:27 1, ZHANG Denan², XU Guangping^2,3, TENG Qiumei², ZHOU Longwu², HUANG Kechao², MOU Zhiyi⁴, SUN Yingjie^2*]]> SHEN Yuyi¹, ZHANG Denan², XU Guangping^2,3, TENG Qiumei², ZHOU Longwu², HUANG Kechao², MOU Zhiyi⁴, SUN Yingjie^2* 1true