2 forest plots with varying habitat heterogeneity in Guangxi karst seasonal rainforests, this study quantified community tree species spatial structures by analyzing intraspecific spatial patterns and interspecific associations of dominant species, testing their responses to karst habitat segregation. The results were as follows:(1)Across all communities, tree species exhibited primarily small- and medium-scale aggregations. On small scale(0-13 m), 85% of species showed aggregated distributions, which progressively decreased to 60% on medium scale(13-30 m). On larger scale(>30 m), random and regular distributions dominated(>80%). As topographic complexity increased among plots, the proportion of small- and medium-scale intraspecific aggregations mean values of aggregated distributions were 63.1%, 89.5%, 94.4%, respectively.(2)Interspecific associations were predominantly spatial segregation and partial overlap. On small scale(0-3 m), such associations accounted for 50%, increased to 70% on small-medium scale(3-20 m)and declined to 40% on larger scale(>20 m). Higher topographic complexity correlated with increased small- and medium-scale spatial segregations and partial overlap mean values were 60.4%, 70.2%, and 83.7%, respectively. These findings suggest that strong karst habitat heterogeneity enhances intraspecific aggregation and promotes the probability of spatial segregation among different tree species, implying that the isolation effect of localized complex habitats is a key driver factor shaping community spatial structure of tree species in karst forest communties. This study underscores the need to evaluate local habitat conditions and design species configurations mimicking natural karst forest communities in rocky desertification restoration efforts.]]> 2025/7/1 10:29:50 1,2, XIANG Wusheng^1,2, DING Tao^1,2, WANG Denghui¹, NONG Zhengquan^2,3, LONG Jifeng^2,3, GUO Yili^1,2, LI Xiankun^1,2, WANG Bin^1,2*]]> LI Dongxing^1,2, XIANG Wusheng^1,2, DING Tao^1,2, WANG Denghui¹, NONG Zhengquan^2,3, LONG Jifeng^2,3, GUO Yili^1,2, LI Xiankun^1,2, WANG Bin^1,2* 9true 2-P), octacalcium phosphate(Ca₈-P), phosphorus adsorbed on the Al oxides surfaces(Al-P), phosphorus adsorbed on the Fe oxides surfaces(Fe-P), occluded phosphorus(O-P)and decalcium phosphate(Ca₁₀-P)in the soils of croplands were found to be higher than those in the soils of artificial forests and natural forests. Furthermore, the contents of Ca₈-P, Fe-P and O-P exhibited the order of croplands > artificial forests > natural forests, whereas the contents of Ca₂-P and phosphorus extracted by hydrochloric acid(HCl-P)demonstrated the order of croplands > natural forests > artificial forests.(2)In high hydrothermal regions, Ca₁₀-P and O-P contents of natural forests soils were significantly higher than in low hydrothermal regions, and phosphorus extracted by enzymes(Enzyme-P)contents of plantation and artificial forests soils were higher than in low hydrothermal regions.(3)Soil inorganic phosphorus fractions Ca₂-P, Ca₈-P, Al-P, Fe-P and Ca₁₀-P contents were significantly and positively correlated with bioavailable phosphorus fractions CaCl₂-P and HCl-P contents. Redundancy analysis showed that Ca₂-P was the key fraction affecting the bioavailable phosphorus fractions. The results indicate that land use types and hydrothermal conditions are key factors influencing the characteristics of soil inorganic phosphorus fractions and bioavailable phosphorus fractions. Increasing the contents of inorganic phosphorus fractions has a positive effect on bioavailable phosphorus fractions. Therefore, consideration should be given to the potential effects of future climate change on the fractions and availability of phosphorus in soil, thereby promoting the restoration of karst ecosystems.]]> 2025/7/1 10:29:50 1, ZHANG Wei^2,4, LIANG Yueming³, WANG Kelin^2,4, HU Peilei^2,4, PAN Fujing^1*]]> YANG Qian¹, ZHANG Wei^2,4, LIANG Yueming³, WANG Kelin^2,4, HU Peilei^2,4, PAN Fujing^1* 8true Zanthoxylum bungeanum and natural secondary forests)in Guizhou karst plateau canyons. The contents of soil organic carbon and its components and the composition and diversity of microbial communities were determined. Changes in soil organic carbon and its components, microbial diversity, and community composition after vegetation restoration were investigated. The relationships between soil organic carbon components and microbial taxa were analyzed. The results were as follows:(1)Vegetation restoration significantly increased the contents of soil organic carbon and its components, particularly in the 0-10 cm soil layer compared with the 10-20 cm layer(P<0.05).(2)Vegetation restoration significantly altered β diversity and relative abundance of soil microbial species, although no significant change was observed in α diversity.(3)The dominant bacterial phyla in all samples were unclassified_k__norank_d__Bacteria, Actinobacteriota, Proteobacteria, and Acidobacteriota, and the main fungal phyla were Ascomycota, unclassified_k__Fungi, Basidiomycota, and Mortierellomycota.(4)Bacteria closely related to soil organic carbon and its components mainly included Asanoa, norank_f__67-14, Solirubrobacter, norank_f__Ilumatobacteraceae, and Streptomyces from Actinobacteriota and unclassified_p__Ascomycota, Setophaeosphaeria, unclassified_o__Helotiales, unclassified_o__Pleosporales, Cladosporium, Setophoma, unclassified_o__Sordariales, Metarhizium, Codinaea, and Exophiala from Ascomycota. The results show that vegetation restoration in karst rocky desertification control can promote the accumulation of soil organic carbon and change the microbial community, among which, Actinobacteriota and Ascomycota are key species affecting changes in soil organic carbon and its components.]]> 2025/7/1 10:29:50 1, LEI Yanting¹, JIANG Xingyu¹, LI Rui¹, LAN Jiacheng^1,2*]]> LI Jiqiong¹, LEI Yanting¹, JIANG Xingyu¹, LI Rui¹, LAN Jiacheng^1,2* 7true Deutzianthus tonkinensis, classified as a national secondary key protected wild plant in China, serves as the foundational species in communities that constitute one of the primary rare vegetation types within the northern tropical karst seasonal rainforests. These communities harbor rich biodiversity and numerous endemic species, possessing significant ecological and economic values. However, the temporal dynamics of species diversity within these communities and their underlying driving factors remain poorly understood. To investigate the temporal dynamics and identify the driving factors of species diversity in D. tonkinensis communities, this study conducted three cycles of periodic re-surveys within a 1 hm² long-term monitoring plot in Nonggang, Guangxi Zhuang Autonomous Region. The objective was to analyze the changes in species diversity from 2012 to 2022 and to explore the impacts of topographic factors on these dynamics. The results were as follows:(1)The importance values of dominant species remained stable. Concurrently, there was an increase in the basal area at breast height, indicating the growth of these species. However, species abundance declined, suggesting a shift in the population structure within the community.(2)A total of 18 rare and occasional species withdrew from the community, resulting in a 14% reduction in species richness. Additionally, the Shannon-Wiener index, a measure of species diversity, declined significantly(P<0.05), indicating a loss of biodiversity within the community.(3)The number of quadrats that significantly contributed to β-diversity, which reflects the variation in species composition among different locations within the community, decreased by 2%. Furthermore, the temporal β-diversity index declined in 80% of the quadrats, indicating that species loss significantly exceeded species gains within the plot. This suggests a trend of homogenization in species composition over time.(4)Elevation had a significant impact on species loss within the plot(P<0.05). This finding highlights the importance of topographic factors, particularly elevation, in shaping the species diversity dynamics within the community. In conclusion, while the overall community structure of Deutzianthus tonkinensis remained stable over the past ten years, significant changes were observed in both α-diversity and β-diversity. The loss of rare and occasional species drove these diversity changes, indicating a potential threat to the biodiversity of the community. Among the topographic factors, elevation emerged as a significant influence on species diversity changes. These research findings are crucial for enhancing our understanding of biodiversity dynamics and their driving mechanisms in karst seasonal rainforests, which are essential for conservation efforts and sustainable management strategies.]]> 2025/7/1 10:29:50 1,2,3, WANG Bin^2,3, LI Dongxing^2,3, LU Fang^2,3, LI Jianxing^2,3, TAO Wanglan^2,3, TANG Nianwu^2,3, GUO Yili^2,3, XIANG Wusheng^2,3*, LI Xiankun^2,3]]> YANG Xufei^1,2,3, WANG Bin^2,3, LI Dongxing^2,3, LU Fang^2,3, LI Jianxing^2,3, TAO Wanglan^2,3, TANG Nianwu^2,3, GUO Yili^2,3, XIANG Wusheng^2,3*, LI Xiankun^2,3 6true Deutzianthus tonkinensis, classified as a national secondary key protected wild plant in China, serves as the foundational species in communities that constitute one of the primary rare vegetation types within the northern tropical karst seasonal rainforests. These communities harbor rich biodiversity and numerous endemic species, possessing significant ecological and economic values. However, the temporal dynamics of species diversity within these communities and their underlying driving factors remain poorly understood. To investigate the temporal dynamics and identify the driving factors of species diversity in D. tonkinensis communities, this study conducted three cycles of periodic re-surveys within a 1 hm² long-term monitoring plot in Nonggang, Guangxi Zhuang Autonomous Region. The objective was to analyze the changes in species diversity from 2012 to 2022 and to explore the impacts of topographic factors on these dynamics. The results were as follows:(1)The importance values of dominant species remained stable. Concurrently, there was an increase in the basal area at breast height, indicating the growth of these species. However, species abundance declined, suggesting a shift in the population structure within the community.(2)A total of 18 rare and occasional species withdrew from the community, resulting in a 14% reduction in species richness. Additionally, the Shannon-Wiener index, a measure of species diversity, declined significantly(P<0.05), indicating a loss of biodiversity within the community.(3)The number of quadrats that significantly contributed to β-diversity, which reflects the variation in species composition among different locations within the community, decreased by 2%. Furthermore, the temporal β-diversity index declined in 80% of the quadrats, indicating that species loss significantly exceeded species gains within the plot. This suggests a trend of homogenization in species composition over time.(4)Elevation had a significant impact on species loss within the plot(P<0.05). This finding highlights the importance of topographic factors, particularly elevation, in shaping the species diversity dynamics within the community. In conclusion, while the overall community structure of Deutzianthus tonkinensis remained stable over the past ten years, significant changes were observed in both α-diversity and β-diversity. The loss of rare and occasional species drove these diversity changes, indicating a potential threat to the biodiversity of the community. Among the topographic factors, elevation emerged as a significant influence on species diversity changes. These research findings are crucial for enhancing our understanding of biodiversity dynamics and their driving mechanisms in karst seasonal rainforests, which are essential for conservation efforts and sustainable management strategies.]]> 2025/7/1 10:29:50 1,2,3, WANG Bin^2,3, LI Dongxing^2,3, LU Fang^2,3, LI Jianxing^2,3, TAO Wanglan^2,3, TANG Nianwu^2,3, GUO Yili^2,3, XIANG Wusheng^2,3*, LI Xiankun^2,3]]> YANG Xufei^1,2,3, WANG Bin^2,3, LI Dongxing^2,3, LU Fang^2,3, LI Jianxing^2,3, TAO Wanglan^2,3, TANG Nianwu^2,3, GUO Yili^2,3, XIANG Wusheng^2,3*, LI Xiankun^2,3 5true P<0.01), with no significant correlation between symbiotic mycorrhizal fungi and other fungal groups.(3)Comparative analysis of typical tree species with high AMF and EMF percentages revealed that AM plant roots exhibited significantly lower values for saturated osmotic potential(Ψ_sft), turgor loss point water potential(Ψ_tlp), and relative water content at turgor loss point(RWC_tlp)compared to EM plants(P<0.05). In conclusion, the dominance of AMF over EMF in the rhizosphere soils of karst forest trees, with AMF being more widely distributed. Notably, other fungal community components in the rhizosphere soil did not directly influence the symbiotic mycorrhizal fungi. Furthermore, comparative analysis showed significant differences in hydraulic traits between tree roots of different mycorrhizal types in karst forests. AM plants root exhibited higher drought tolerance, maintaining water absorption and physiological metabolism under drought stress, compared to EM plants root. This enhanced drought resistance in AM plants roots suggests greater adaptability to the unique karst habitat conditions. Future research should focus on the application of advanced sequencing technologies to further elucidate specific mycorrhizal fungi associations. This study contributes to the future isolation and identification of mycorrhizal fungi, providing scientific evidence for tree species selection and the application of mycorrhizal biotechnology in desertification control.]]> 2025/7/1 10:29:50 1, XU Liming^2*, LUO Longde¹, LI Qixia¹, JIANG Guofeng^1*]]> WANG Bingchao¹, XU Liming^2*, LUO Longde¹, LI Qixia¹, JIANG Guofeng^1* 4true Morus alba(mulberry)varieties with high drought resistance suitable for planting in the karst areas of Guangxi, this study investigated five mulberry varieties from Huanjiang region, namely ‘Guisang 5', ‘Guisang 6', ‘Guisangyou 12', ‘Nongsang 14', and ‘Yu 711'. A total of 24 leaf functional traits were measured, including chlorophyll, osmotic regulatory substances, anthocyanidin, malondialdehyde, antioxidant enzyme activities, as well as anatomical traits such as conduit diameter, conduit wall reinforcement, leaf thickness, upper and lower epidermis thickness, palisade mesophyll thickness, spongy mesophyll thickness, stomatal size, and stomatal density, etc. These traits were evaluated through principal component analysis, membership function analysis, and cluster analysis to identify leaf functional traits associated with drought resistance and to select the varieties with stronger drought resistance. The results were as follows:(1)Principal component analysis revealed that the key leaf functional traits associated with drought resistance in the five mulberry varieties were chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, malondialdehyde, superoxide dismutase activity, stomatal size, stomatal density, conduit wall reinforcement, and spongy tissue thickness. These traits were found to have significant correlations with the drought resistance of the varieties.(2)The membership function analysis ranked the drought resistance of the five varieties as follows: ‘Nongsang 14'>‘Guisangyou 12'>‘Guisang 5'>‘Guisang 6'>‘Yu 711'. This ranking was confirmed by the subsequent cluster analysis, which grouped ‘Nongsang 14', ‘Guisangyou 12', and ‘Guisang 5' together, while ‘Guisang 6' and ‘Yu 711' were placed in a separate group. The cluster analysis results were consistent with the membership function analysis.(3)‘Nongsang 14', ‘Guisangyou 12', and ‘Guisang 5' exhibited better drought resistance, which was attributed to their more efficient physiological regulation mechanisms and optimal anatomical features. The findings of this study provide a solid scientific foundation and valuable theoretical insights for the selection of drought-resistant mulberry varieties in the karst regions of Guangxi.]]> 2025/7/1 10:29:50 1, CHEN Guanrong¹, LI Yanting¹, XIE Yanjun¹, LI Xiaodong¹, HUANG Kangdong², WEN Liuying³, SHI Chenyu^1*]]> QIN Lanli¹, CHEN Guanrong¹, LI Yanting¹, XIE Yanjun¹, LI Xiaodong¹, HUANG Kangdong², WEN Liuying³, SHI Chenyu^1* 3true -2)on phosphorus availability in calcareous soil of karst forest were analyzed based on laboratory culture experiment. The results were as follows:(1)The contents of soil available phosphorus(Olsen-P), hydrochlori acid extraction of phosphorus(HCl-P)and citric acid extraction of phosphorus(Citrate-P)in soil were significantly increased with the addition of bagasse biochar addition concentration and time.(2)The highest of soil microbial biomass phosphorus(MBP)content and alkaline phosphatase(ALP)activity were observed in 5 t·hm^-2 biochar addition concentration.(3)The content of Olsen-P was significantly positively correlated with the contents of HCl-P and Citrate-P(R2=0.68; R2=0.77), while Olsen-P content was not significantly correlated with enzyme extraction of phosphorus(Enzyme-P)(R2=0.14). The results indicated that an increasing in soil available phosphorus was mainly from inorganic phosphorus activated by weak acid when bagasse biochar was applied into calcareous soils.(4)Random forest model analysis showed that soil phosphorus availability was significantly affected by HCl-P, Citrate-P, MBP, Enzyme-P and soil pH. To sum up, these results indicate that 5 t·hm^-2 bagasse biochar addition concentration is the most appropriate concentration to improve soil phosphorus availability of karst forest, considering the factors related to phosphorus availability.]]> 2025/7/1 10:29:50 1, NING Kai^2,3, PAN Fujing³, YANG Xi^2,3, HE Xinyu^2,3, LIANG Yueming^2,4,5,6*]]> JIANG Xiaoxiao¹, NING Kai^2,3, PAN Fujing³, YANG Xi^2,3, HE Xinyu^2,3, LIANG Yueming^2,4,5,6* 2true 2025/7/1 10:29:50 1,2, CHANG Shili^1,2, MO Minglin^1,2, LU Zhaocen², CHEN Hailing^2*]]> SU Min^1,2, CHANG Shili^1,2, MO Minglin^1,2, LU Zhaocen², CHEN Hailing^2* 1true