Lysimachia danxiashanensis, a new Primulaceae species, endemic to the Danxia landscape in Guangdong Province, China, is described and illustrated. This new species is morphologically similar to L. pseudohenryi, L. phyllocephala, L. congestiflora and L. kwangtungensis, but it differs from the similar species by its purplish-red plants, petiole without wings, calyx with orange glandular and the corolla margin serrated on upper half with orange-red glandular punctates. This new species belongs to Lysimachia subgen. Lysimachia sect. Nummularia. Phylogenetic analysis confirmed that L. danxiashanensis is a distinct clade, based on the combined data of ITS and rbcL sequences. The conservation status of the new species was evaluated as Endangered (EN) according to IUCN Red List Categories and Criteria.

Eucalyptus is harvested for wood and fiber production in many tropical and sub-tropical habitats globally. Plantation has been controversial because of its influence on the surrounding environment, however, the influence of massive Eucalyptus planting on soil microbial communities is unclear. Here we applied high-throughput sequencing of the 16S rRNA gene to assess the microbial community composition and diversity of planting chronosequences, involving two, five and ten years of Eucalyptus plantation, comparing to that of secondary-forest in South China. We found that significant changes in the composition of soil bacteria occurred when the forests were converted from secondary-forest to Eucalyptus. The bacterial community structure was clearly distinct from control and five year samples after Eucalyptus was grown for 2 and 10 years, highlighting the influence of this plantation on local soil microbial communities. These groupings indicated a cycle of impact (2 and 10 year plantations) and low impact (5-year plantations) in this chronosequence of Eucalyptus plantation. Community patterns were underpinned by shifts in soil properties such as pH and phosphorus concentration. Concurrently, key soil taxonomic groups such as Actinobacteria showed abundance shifts, increasing in impacted plantations and decreasing in low impacted samples. Shifts in taxonomy were reflected in a shift in metabolic potential, including pathways for nutrient cycles such as carbon fixation, which changed in abundance over time following Eucalyptus plantation. Combined these results confirm that Eucalyptus plantation can change the community structure and diversity of soil microorganisms with strong implications for land-management and maintaining the health of these ecosystems.

Irrigation and fertilization are essential management practices for increasing forest productivity. They also impact the soil ecosystem and the microbial population. In order to examine the soil bacterial community composition and structure in response to irrigation and fertilization in a Eucalyptus plantations, a total of 20 soil samples collected from Eucalyptus plantations were analyzed using high-throughput sequencing. Experimental treatments consisting of control (CK, no irrigation or fertilization), fertilization only (F), irrigation only (W), and irrigation and fertilization (WF). The results showed a positive correlation between soil enzyme activities (urease, cellulase, and chitinase) and fertilization treatments. These enzyme activities were also significantly correlated with the diversity of soil bacterial communities in Eucalyptus plantations.. Bacteria diversity was considerably increased under irrigation and fertilization (W, F, and WF) treatments when compared with the CK treatment. Additionally, the soil bacterial richness was increased in the Eucalyptus plantations soil under irrigation (W and WF) treatments. The Acidobacteria (38.92–47.9%), Proteobacteria (20.50–28.30%), and Chloroflexi (13.88–15.55%) were the predominant phyla found in the Eucalyptus plantations soil. Specifically, compared to the CK treatment, the relative abundance of Proteobacteria was considerably higher under the W, F, and WF treatments, while the relative abundance of Acidobacteria was considerably lower. The contents of total phosphorus, accessible potassium, and organic carbon in the soil were all positively associated with fertilization and irrigation treatments. Under the WF treatment, the abundance of bacteria associated with nitrogen and carbon metabolisms, enzyme activity, and soil nutrient contents showed an increase, indicating the positive impact of irrigation and fertilization on Eucalyptus plantations production. Collectively, these findings provide the scientific and managerial bases for improving the productivity of Eucalyptus plantations.

Cynanchum pingtaoi S.Jin Zeng, G.D.Tang & Miao Liao, sp. nov. (Apocynaceae) from Yunnan Province, China, is described and illustrated based on morphological and molecular evidence. Its deeply cordate to reniform leaves and campanulate, large flowers show that it is a member of former Raphistemma Wall., which has been included in Cynanchum L.. It is different from all former Raphistemma species by the broadly ovate corolla lobes, purple-red corolla and connivent corona tip slightly exceeding the corolla throat. Meanwhile, Cynanchum longhushanense G.D.Tang & Miao Liao, nom. nov. is proposed as replacement name for Raphistemma brevipedunculatum Y.Wan, which was considered a synonym of Cynanchum hooperianum (Blume) Liede & Khanum but is here reinstated as a distinct species because of significant morphological differences.

Morinda officinalis, a traditional medicinal plant in southern China, has a well-established cultivation history in Zhaoqing and Yunfu City of the Guangdong Province, China, contributing significantly to the local economy. Inadequate cultivation practices of Morinda officinalis may heighten the risk of landslide occurrences due to its specific growth and harvesting characteristics. This issue presents a challenge to the sustainable advancement of agriculture and forestry in the area, underscoring the necessity for scholarly intervention to address and devise effective remedies. This research utilized the MaxEnt model to assess landslide susceptibility and habitat suitability for Morinda officinalis, aiming to delineate appropriate cultivation zones amidst changing climatic conditions. The findings indicate that the model demonstrated a high level of accuracy, achieving combined AUC values of 0.802 for landslide susceptibility and 0.861 for habitat suitability evaluations, meeting the criteria for classification as “highly accurate”. Regions such as the Yun’an District, Luoding City, and the Xinxing District in Yunfu City were identified as having a low landslide risk and being highly conducive to Morinda officinalis cultivation under current climate conditions. Future projections indicate an anticipated expansion of the species’ distribution area between 2021 and 2040 under different climate scenarios, with subsequent variations. Spatial analysis unveiled a notable trend in the research area, indicating greater suitability for cultivation in the southern region compared to the northern region. This suggests that Yunfu City holds promise for facilitating the cultivation of Morinda officinalis more effectively than Zhaoqing City. This research offers a practical approach for promoting the sustainable growth of the regional Morinda officinalis industry, while also serving as a valuable resource for other economic crops encountering comparable developmental obstacles.