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Microbial communities are an important component of mangrove ecosystems. In order to reveal the diversity of endophytic fungi in the mangrove ferns Acrostichum speciosum and A. aureum in China, the internal transcribed spacer (ITS) regions of endophytic fungi in four plant tissues (leaves, petioles, roots, and rhizomes) from three locations (Zhanjiang, Haikou, and Wenchang) were sequenced. The richness, species composition, and community similarity were analyzed. The main results are as follows: the dominant fungi in A. speciosum and A. aureum belonged to the phyla Ascomycota and Basidiomycota, accounting for more than 75% of the total identified fungi; in terms of species composition at the operational taxonomic unit (OTU) level, the endophytic fungi in A. aureum were more diverse than those in A. speciosum, and the endophytic fungi in rhizomes were more diverse than in other tissues. In Zhanjiang, both A. speciosum and A. aureum showed the richest diversity of endophytic fungi, both at the OTU classification level and in terms of species composition. Conversely, the richness of endophytic fungi in the samples of A. speciosum from Wenchang and Haikou is extremely low. The regional differences in dominant fungi increase with the degrading of taxonomic levels, and there were also significant differences in the number of unique fungi among different origins, with Zhanjiang samples having a larger number of unique fungi than the other locations. There were significant differences in the dominant fungi among different tissues, with Xylariales being the dominant fungi in rhizomes of A. speciosum and Hypocreales being the dominant fungi in the petioles, roots, and rhizomes of A. aureum. Overall, the community similarity of endophytic fungi among locations is moderately dissimilar (26–50%), while the similarity between tissues is moderately similar (51–75%). The low diversity of endophytic fungi could be one of the main reasons for the endangerment of A. speciosum. The protection of the diversity of endophytic fungi in the underground parts of A. speciosum is essential for the conservation of this critically endangered mangrove fern. [ABSTRACT FROM AUTHOR]

Dryopteris jinpingensis, a new species of diploid, sexually reproductive ferns of Dryopteridaceae from Yunnan, southwestern China, is described and illustrated. Morphologically, D. jinpingensis is similar to D. gaoligongensis but unique in elongated lanceolate laminae, sessile or subsessile pinna stalks, and overlapping membranous scales adnate to stipe base. Phylogenetic analyses based on both plastome and the nuclear AK1 gene sequences showed that D. jinpingensis is sister to D. gaoligongensis. A detailed taxonomic description with line drawings is provided, and its conservation status is evaluated to be critically endangered. [ABSTRACT FROM AUTHOR]

In this study, the mating system of the endangered aquatic fern Ceratopteris thalictroides in China was investigated using microsatellite markers. The estimates of the multilocus outcrossing rate (tm) and single-locus outcrossing rate (ts) were high at the species level (tm = 0.701 and ts = 0.595, respectively), indicating that C. thalictroides is a predominantly outcrossing species. Negative F (inbreeding coefficient of the maternal parents) values (-0.137) at the species level indicated an excess of heterozygotes and low inbreeding in the populations analyzed. Our investigation revealed that some of the natural and ex situ conservation populations of C. thalictroides have a prolific capacity for vegetative growth. The results showed that the homosporous pteridophyte C. thalictroides in China predominantly favors gametophytic crossing with a certain level of inbreeding along with vegetative growth. Ten populations have been established for ex situ conservation in Wuhan, China, with a survival rate of more than 90%, and mature spores were collected from them. Several factors, including high dispersal of spores and gametophytes by flowing water, high gene flow, and the wide distribution of the species in China, with the occurrence of some large populations, may have resulted in a high outcrossing rate in Chinese C. thalictroides. The high outcrossing rate of C. thalictroides showed that ex situ plantings are most suitable for enhancing possible mixing of the different populations, thus minimizing inbreeding. [ABSTRACT FROM AUTHOR]

A unique petrified tree fern displaying distinct patterns was recently discovered in northeast China, attracting considerable interest. This study provides a comprehensive set of data for this material obtained through standard gemological testing, petrographic observation, scanning electron microscopy, energy-dispersive spectroscopy, electron probe microanalysis, and Raman spectroscopy. The petrified tree fern exhibits colors ranging from golden yellow to brown, with additional variations caused by iron oxides. Chalcedony is the primary mineral component, while the presence of metastable moganite gives chalcedony its fibrous nature, contributing to the delicate structure of the samples. The surface pattern originates from plant structures preserved during silicification, further confirming the samples belong to the extinct Cretaceous period tree fern Tempskya sp. [ABSTRACT FROM AUTHOR]

• First Late Triassic palynological assemblage reported from Nanjing area. • Palynological composition of Fanjiatang Formation indicates a Norian-Rhaetian age. • Paleovegetation was reconstructed combing palynofloral and macrofloral data. • Palynological composition suggests a tropical to subtropical warm and humid climate. The end-Triassic is characterized by a significant biotic crisis in both marine and terrestrial realms. However, terrestrial records in eastern Tethys are relatively limited, especially in eastern China. The Fanjiatang Formation represents the Upper Triassic sequence in southern Jiangsu and Anhui provinces of eastern China, yielding a rich plant and bivalve fossil record. The present study provides the first detailed palynological investigation for the Upper Triassic of Nanjing area, eastern China. Six of twenty processed palynological samples are productive, and more than 70 terrestrial spore and pollen fossil taxa were identified. A palynological assemblage, namely, the Concavisporites – Dictyophyllidites – Kyrtomisporis – Classopollis Assemblage was established, characterized by abundant fern spores, mainly including Concavisporites , Dictyophyllidites and Kyrtomisporis , and much less abundant gymnosperm pollen grains (important taxa include Alisporites , Chasmatosporites , and Classopollis), indicating a Late Triassic Norian–Rhaetian age. In conjunction with previously reported macro-plant data, the palynofloral analysis reveals a vegetation dominated by ferns, with diverse cycadophytes, less abundant lycophytes, bryophytes, equisetales, ginkgophytes and seed ferns, and a few conifers. Paleovegetation and semiquantitative palynological analysis permit a paleoecological interpretation, suggesting a lowland groundcover-dominated vegetation under (sub)tropical warm and humid climate in Nanjing area during this time interval. More detailed palynological and macro-plant data through the whole Upper Triassic in this region are necessary in the future to better reveal the Late Triassic paleoecological settings and variations on land prior to the end-Triassic mass extinction in eastern Tethys. [ABSTRACT FROM AUTHOR]

Ferns have a significant role as a phytogenetic intermediary connecting lower and higher plants. Throughout history, humans have employed them for many purposes, such as adorning landscapes, serving as household implements, providing sustenance, and facilitating the creation of artisanal products. Furthermore, many plants have been discovered to possess medicinal properties. Ferns exhibit a diverse range of secondary metabolites possessing various bioactivities, which hold potential for therapeutic use in numerous disease treatments. The present study was to investigate the species composition, floristic distribution features, ecological characteristics, and resource preservation and utilisation of ferns in three provinces located in northeastern China, namely Liaoning, Jilin, and Heilongjiang. This investigation was conducted by means of literature analysis and data sorting. The findings of the study indicate that the surveyed areas had a total of 16 families, 39 genera, and 164 species of ferns, excluding Lycopodium. The most prevalent families observed in these regions were Dryopteridaceae and Athyriaceae, while the dominant genera were Athyrium, Dryopteris, and Equisetum. The dominant distribution types seen in the family were the northern temperate distribution type and the old world temperate distribution type. Similarly, the dominant distribution types observed in the genus were the north temperate distribution type and the H-S-J distribution type. Within this region, there exists a total of eight fern species that are exclusive to this particular area. The predominant ecological classification of fern species in this region primarily consists of soil ferns. Habitats had a vertical distribution spanning from 30 to 2040 metres, predominantly concentrated within the altitude range of 500 to 1000 metres. From a conservation standpoint, Cystopteris sudetica can be classified as near threatened (NT) in terms of fern resource protection, while Asplenium scolopendrium subsp. japonicum is categorised as vulnerable (VU). Ophioglossum thermale Kom. is classified as a nationally protected plant of Grade-II status in China. In relation to the utilisation of fern resources, it was observed that there existed various categories of ferns, namely edible, medicinal, ornamental, and multifunctional ferns. [ABSTRACT FROM AUTHOR]

Many hemiparasites attach to a range of different host species, resulting in complex parasite–host interactions. Comprehensive molecular phylogenies allow the investigation of evolutionary relationships between these host plants. We surveyed the hosts of the laurel dodder (Cassytha filiformis, Lauraceae) in China, representing 184 species from 146 genera, 67 families, and spanning flowering plants, conifers, and ferns, using host phylogenetic relationships to investigate the susceptibility to attack by this hemiparasitic plant among the vascular plants. The process of produced well-formed haustoria by C. filiformis was also observed in detail for six different hosts. Our results show that C. filiformis grows mainly on trees and shrubs from phylogenetically divergent members of the rosid and asterid eudicot clades, often attacking multiple adjacent hosts simultaneously, and forming extensive colonies. However, whether and to what extent transitions between C. filiformis and host plants occur remain unclear. Physiological evidence for the complex parasite–host species interactions need to be studied in the future. [ABSTRACT FROM AUTHOR]

Dongtian Park is a forest park in Dongtian Lake Ecological Tourism Resort in Meizhou City, South China. Through investigation and analysis of sample methods of the forest community structure and plant diversity in this park, the results showed that there were 181 plant species, belonging to 138 genera in 76 families, including 48 trees, 60 shrubs, 36 herbs and 37 lianas. The flora is a subtropical evergreen broad-leaved forest with some distinct tropical properties, and evergreen trees accounted for 48.62% of total plant species. The dominant species in the tree layer were Schima superba, Pinus massoniana, Cinnamomumparthenoxy-lon, etc., and those in the shrub layer were Bambusa textilis, Aidia cochinchinensis, Bhaphiolepis indica, etc., and in herb layer were Carex baccans, Adiantum flabellulaium, Cibotium barometz, etc., and the lianas mainly included Smilax hypoglauca, Callerya dielsiana, Trachelospermum jasminoides, etc. There were few adults of dominant species in the tree layer, S. superba and P. massoniana also lacked seedlings, they would still maintain their dominant position for a quite long period, but Cyclobalanopsis neglecta had sufficient seedling reserves and would be most likely to become a dominant species in future. The community had relatively rich species, many ferns and lianas and complex hierarchy. The evenness, Shannon-Wiener diversity, Pielou uniformity and Simpson index were higher in the shrub layer than in the tree and herb layer, and the Simpson index was the lowest (0. 928 0) in the herb layer and Shannon-Wiener diversity index was the highest (7.585 3) in the liana layer. [ABSTRACT FROM AUTHOR]

The fern genus Cyrtomium is generally recognized as a genus difficult to identify taxonomically. Here, the micro‐morphological characteristics of nine species and one cultivar of Cyrtomium from Shandong Province of China were studied using scanning electron microscopy (SEM): C. confertiserratum, C. falcatum, C. fortunei, C. polypterum, C. reflexosquamatum, C. semifertile, C. shandongensis, C. tukusicola, C. yamamotoi and C. yamamotoi var. intermedium. The morphology of the pinna margin, upper and lower epidermis, indusia, shape of pinnae, sori distribution and spore morphology were carefully examined and photographed under SEM. The results showed that the micro‐morphological characteristics of the pinna margin, upper and lower epidermis, indusia and spore morphology were stable within species and show significant differences between interspecies. The results provide not only important scientific evidence for the micro‐morphological classification and identification of Cyrtomium, but also an important scientific basis for the development and utilization of this genus for medicine use and the protection of germplasm resources. [ABSTRACT FROM AUTHOR]

Although the effects of N deposition on forest plants have been widely reported, few studies have focused on rare and endangered fern species (REFs). Information is also lacking on the effects of micro-environments on REFs. We investigated the effects of N addition (canopy and understory N addition, CAN, and UAN) and micro-environments (soil and canopy conditions) on the functional traits (growth, defense, and reproduction; 19 traits in total) of two REFs—Alsophila podophylla and Cibotium baromet—in a subtropical forest in South China. We found that, compared to controls, CAN or UAN decreased the growth traits (e.g., plant height, H) of C. baromet, increased its defense traits (e.g., leaf organic acid concentrations, OA), delayed its reproductive event (all-spore release date), and prolonged its reproductive duration. In contrast, A. podophylla showed increased growth traits (e.g., H), decreased defense traits (e.g., OA), and advanced reproductive events (e.g., the all-spore emergence date) under CAN or UAN. Meanwhile, the negative effects on the C. baromet growth traits and A. podophylla defense traits were stronger for CAN than for UAN. In addition, the soil chemical properties always explained more of the variations in the growth and reproductive traits of the two REFs than the N addition. Our study indicates that, under simulated N deposition, C. baromet increases its investment in defense, whereas A. podophylla increases its investment in growth and reproduction; this may cause an increasing A. podophylla population and decreasing C. baromet population in subtropical forests. Our study also highlights the importance of considering micro-environments and the N-addition approach when predicting N deposition impact on subtropical forest REFs. [ABSTRACT FROM AUTHOR]

Hymenasplenium obtusidentatum, a new fern species of the H. excisum subclade of Hymenasplenium (Aspleniaceae) from south and southwestern China was described. Molecular phylogenetic analyses and morphological observations of H. obtusidentatum and related species clearly indicated that this is a distinct taxonomic entity. Phylogenetically, H. obtusidentatum was confirmed to represent a diverging lineage in the H. excisum subclade of Hymenasplenium and was closely related to one lineage that includes accessions identified as H. obscurum, H. pseudobscurum and H. tholiformis. Morphologically, H. obtusidentatum can be distinguished by the combination of its lamina base truncate, stipe not shiny and with color of reddish brown to dark brown, and pinna marginal teeth that are not sharp, but blunt or rounded. A complete species description and comparison with related species in the H. excisum subclade were provided. The holotype of H. obtusidentatum was designated. [ABSTRACT FROM AUTHOR]

The recalcitrant understory fern layer is an important ecological filter for seedling regeneration, yet how the fern layer influences seedling regeneration dynamics remains unclear. Here we transplanted 576 seedlings of four dominant tree species, Castanopsis fargesii, Lithocarpus glaber, Schima superba and Hovenia acerba, to the treatments of Diplopterygium glaucum retention and removal under an evergreen broad-leaved forest in eastern China. We monitored the survival, growth and biomass data of these seedlings for 28 months, and then used generalized linear mixed models to evaluate the treatment effects on seedling survival, growth, biomass and rootshoot ratio. Our results showed that fern retention significantly inhibited the seedling establishment of all four species. During the seedling development stage, the seedling relative growth rate of L. glaber decreased under fern retention, which was not the case for the other three species. Root-shoot ratio of C. fargesii and L. glaber increased significantly under fern retention. Our findings provide new evidence of the filtering effect of a recalcitrant fern understory. Notably, we observed that the response of tree seedlings to the recalcitrant fern understory was more sensitive in the establishment stage. Finally, our work highlights that the filtering effect of the recalcitrant fern understory changes depending on the regeneration stages, and that shadetolerant species, C. fargesii and L. glaber were even more affected by fern disturbed habitats, suggesting that effective management should attempt to curb forest fern outbreaks, thus unblocking forest recruitment. [ABSTRACT FROM AUTHOR]

Adiantum nelumboides X.C.Zhang (Adiantaceae) is a rare and endangered fern endemic to the Three Gorges Region in southwest China. Here, its geographical distribution, habitat and resource status is analyzed based on literature, interview and field investigations. The ecological environment, climatic characteristics, soil nutrients and associated vegetation were statistically analyzed. Principal component analysis (PCA) was used to find the main environmental factors affecting the distribution and survival of A. nelumboides, and the main threat factors were explored. The results show 1) A. nelumboides is mostly distributed along the banks of the Yangtze River between Wanzhou District in the east and Shizhu County in the west of the Chongqing Three Gorges Reservoir area, across 30°31′–30°29′N and 108°10′–108°17′E, on cliffs at an altitude of 250–356 m a.s.l., a slope of 65–87° and northeast aspect, and 2) mean annual temperature in the distribution area of A. nelumboides range from 16.5 to 18.1°C. It is a subtropical species that prefer a climate with abundant rainfall, deep shade and long frost‐free period, and grows in wet, acidic or weakly acid brown purple soil and purple‐black soil. Soil nutrients are abundant, but available phosphorus is relatively lacking in the habitat of the species. The main factors threatening A. nelumboides are competition for resources, severe destruction of habitat by human activities, low survival rate of spores and low natural renewal ability. The study suggests that protection based on origin and ex situ conservation should be implemented, artificial cultivation should be carried out, and wild populations should be restored to increase population heterogeneity. [ABSTRACT FROM AUTHOR]

The aim of the study was to explore the relationship between species diversity of understory ferns and plant biomass in high-nitrogen habitats in China. Four species Cyrtogonellum fraxinellum, Pteris nipponica, Humata griffithiana and Pteris fauriei were chosen to set up three species richness (1, 2 and 4 species) and a total of 11 species combinations at two nitrogen habitats (control and 10 g N m2 yr-1 ). Plant biomass and soil physical and chemical properties were determined. The study had the following results: (1) Species richness had no significant effect on plant biomass under both nitrogen habitats. (2) Under both nitrogen habitats, species combination had a significant effect on plant biomass. (3) The presence of P. nipponica and P. fauriei significantly increased the plant biomass, and the presence of C. fraxinellum significantly reduced the plant biomass under two nitrogen habitats. (4) Nitrogen addition significantly increased soil nitrogen content, but plant species diversity had no significant effect on soil physical and chemical properties. (5) There was a significantly negative correlation between plant biomass (aboveground, underground, and total) and soil phosphorus content; there was also a significantly negative correlation between plant underground biomass and soil pH. Assembling specific species combinations can improve plant biomass and promote ecological restoration under high nitrogen habitat. [ABSTRACT FROM AUTHOR]

A new tree fern of the family Tempskyaceae, Tempskya hailunensis sp. nov., is described herein based on a silicified trunk from the Cretaceous of Hailun City, Heilongjiang Province, Northeast China. The new species is composed of dichotomizing large stems surrounded by a mesh of adventitious roots, petioles, and leaf-like structures, constituting a solid and compact false trunk. The dorsiventral stems contain solenosteles that have long internodes with mostly two leaf traces. The stem cortex consists of a sclerenchymatous outer zone and a parenchymatous inner zone, and the stem pith is divided into a parenchymatous outer zone and a sclerenchymatous inner zone. Wide multicellular scales are attached to the stem epidermis. Leaf-like structures embedded among adventitious roots in the trunk are isobilateral, thick, and without distinct intercellular spaces. Also present are dispersed annuli of sporangia, which are only few cells long and apparently uniseriate. Though it cannot be fully ruled out that these vegetative and fertile remains belong to epiphytes that colonized the Tempskya trunk, the consistent and exclusive occurrence of these particular types of remains makes it likely that they belonged to the Tempskya plant itself. This new species represents only the second fossil record of Tempskya from China, increasing the known diversity of this genus during the Cretaceous both in Asia and globally. Moreover, it provided evidence for recognizing probable leaf structure and growth habit of Tempskya. • A new Cretaceous fern of Tempskya with leaves described from China. • Isobilateral leaf fragments and annuli are present among adventitious roots. • Leaves grew under environment with adequate illumination. [ABSTRACT FROM AUTHOR]

The Early Cretaceous terrestrial revolution involved global shifts from gymnosperm‐ to angiosperm‐dominated floras. However, responses of insect herbivores to these changes remain unexamined. We evaluated 2 176 highly sampled plant specimens representing 62 species/morphotypes from the 126 Ma Dawangzhangzi plant assemblage of Northeastern China. Our study consisted of horsetails, ferns, ginkgoaleans, czekanowskialeans, conifers, and an angiosperm. Their herbivory was evaluated by the functional feeding groups of hole feeding, margin feeding, and surface feeding (ectophytic feeders); piercer and suckers, and ovipositing insects (ectoendophytic feeders); mining, galling, and borings (endophytic feeders); and pathogens, collectively constituting 65 damage types (DTs). The plant assemblage was assessed for herbivory richness by DT richness, component community structure, and DT specialization on plant hosts; for herbivory intensity, it was evaluated for DT frequency, herbivorized surface area, and feeding event occurrences. Using feeding event occurrences, the data supported seven species/morphotypes as most intensely herbivorized: Liaoningocladus boii (76.6%), Czekanowskia sp. 1 (8.4%), Czekanowskia rigida (4.10%), Lindleycladus lanceolatus (3.5%), Ginkgoites sp. 2 (2.0%), Podozamites sp. 1 (1.1%), and Solenites sp. 1 (0.9%). The most herbivorized taxa were pinaleans (conifers), then czekanowskialeans, and lastly ginkgoaleans; the monodominant component community was the conifer Liaoningocladus boii. DT host specialization levels were low. The plant assemblage had an overall low 0.86% of foliage removed by herbivores, explained by physical and chemical antiherbivore defenses, and parasitoid attack. Although Paleozoic, gymnosperm‐dominated assemblages had greater herbivory, component community structure of the three most herbivorized taxa are more similar to modern bracken fern and willow than modern gymnosperm taxa. [ABSTRACT FROM AUTHOR]

Understanding how forest fragment size, topography, forest structure, and soil properties affect plant diversity remains a crucial question in conservation biology, with ferns often being understudied. To address this knowledge gap, we surveyed the abundance, species richness, and composition of ferns in a tropical landscape in south China using 75 sites in 42 forest fragments. We then used a multi-model inference approach to assess whether fern abundance, richness, and composition were better explained by (a) fragment size, (b) topography (slope, aspect), (c) forest structure (tree basal area, light availability), or (d) soil properties (pH, Carbon, Nitrogen, Phosphorous, Calcium, Magnesium, water availability, and proportion of clay, silt, and sand). We also conducted a nestedness analysis to examine whether the composition of the fern communities in smaller fragments (0.4–1 km²) differed or represented a subset of the communities found in larger fragments (e.g., >10 km²). We found that (a) fern abundance was mostly influenced by soil properties, slope, and aspect, (b) fern species richness by soil properties and slope, and (c) fern species composition by forest structure, specifically, tree basal area. We also found that fern species composition was not nested in the landscape, suggesting that smaller forest fragments had different communities from larger fragments. Our results suggest also that soil properties play an important role in maintaining fern abundance and diversity and therefore protecting soil can help conserve ferns in fragmented landscapes. [ABSTRACT FROM AUTHOR]

There are about 10% of the world's land plants in China, of which 11% are threatened species. Here, we used China as a proxy to identify hotspots of threatened species, evaluate the effectiveness of current conservation networks and assess the correlations between distribution patterns of different groups. We built the most complete database of 3,881 species of threatened land plants in China (TLPCs) to date, based on 43,710 occurrence records at county level. A total of 467 counties identified as hotspot by species richness, complementarity, and weighted algorithms, mostly confined to the mountainous areas in southern China, which account for 15.58% of land area, however, hold 95.34% of the total TLPCs. The correlation analysis revealed weak to moderate relationship between the distribution patterns of three groups (bryophytes, ferns, and gymnosperms) and angiosperms of TLPCs. We found 86.34%, 84.05% and 95.77% of TLPCs protected by NNRs, PNRs and NRs [nature reserves, including both national NRs (NNRs) and provincial NRs (PNRs)], respectively. Besides, there were 41.11% and 18.84% of hotspots identified as conservation gaps of NNRs and NRs, respectively. In conclusion, the NNRs do not play a more dominant role in conserving TLPCs diversity in comparison to PNRs. We proposed that conservation planning need to be established in the periphery of Yunnan-Guizhou Plateau due to a large number of hotspots and conservation gaps located in this area. Since a large proportion of unprotected TLPCs are critically endangered and narrow-ranged species, it is urgent to set priorities for their conservation in the nearest future. [ABSTRACT FROM AUTHOR]

Holocene palynological evidence from the Bohai Sea coastal areas have not been sufficiently discovered. In this study, we carry out analyses using detailed palynological records of pollen, spores, freshwater algae and marine dinoflagellate cysts from Borehole X1 on the south coastal plain of Laizhou Bay, Bohai Sea, northern China. The results based on radiocarbon chronology show vegetation evolution, hydrologic variability and sea-level fluctuations during the Holocene. Abundant non-arboreal pollen (mainly, Artemisia, Chenopodiaceae and grass-type Poaceae) and small amounts of arboreal pollen (mainly Pinus and Quercus-deciduous) and fern spores were identified in this study, suggesting that coastal steppes and coniferous and broadleaved mixed forests flourished in the study area and its adjacent areas, and a cold and dry climate with less precipitation and lower sea-level than the present during the Early Holocene, ca. 9910–7440 cal. yr BP. After that, the steppe areas began to shrink, and coniferous and broadleaved mixed forest areas began to expand, indicating a relatively warm and humid climatic conditions, with more precipitation and marine transgression processes during the Mid-Holocene, ca. 7440–3650 cal. yr BP. Afterwards, relatively cool and dry climatic conditions predominated, with less precipitation. While sea-level continued to rise slowly during the Late Holocene, ca. 3650 cal. yr BP to the present, and the steppe areas shrank, the coniferous and broadleaved mixed forest areas continued to expand. [ABSTRACT FROM AUTHOR]

The ferns of Adiantum Series Gravesiana (Pteridaceae) consist of species that occur exclusively on Danxia (A. juxtapositum) and Karst (A. mariesii, A. longzhouensis, A. dentatum, A. obovatum, and A. gravesii) landforms. We cultured representatives of these six species from 20 different populations on both agar and soil to investigate and compare their gametophyte development. All species had the Vittaria-type pattern of spore germination except A. obovatum, for which we missed the best time to observe this developmental phase. However, two different patterns of subsequent development were observed: the Adiantum-type (i.e., naked, cordate mature gametophyte thallus) in A. mariesii, A. longzhouensis, A. juxtapositum, and A. gravesii and the Kaulinia-type (i.e., naked, ribbon-shaped mature gametophyte thallus) in A. dentatum and A. obovatum. All populations from A. juxtapositum and A. gravesii possess the same Adiantum-type, suggesting that Karst and Danxia soils were not the main factor causing the differences in gametophyte development. The Kaulinia-type adult thallus has not been observed previously in Adiantum and may be an adaptive strategy for survival within the relatively harsh micro-habitats experienced by A. dentatum and A. obovatum compared to other members of this series. [ABSTRACT FROM AUTHOR]

• Reinvestigation of Danaeopsis fecunda fossils fromYunnan Province in China. • Danaeopsis lived in warmer and humid, rarely semi-arid habitats during the Triassic. • Danaeopsis has a wider geographical range than its extant relatives, which could be largely related to the Triassic palaeoclimate pattern. The genus Danaeopsis Heer ex Schimper is a typical and widespread Triassic eusporangiate fern and is also an important species in China with abundant records. In this study, a further investigation of Danaeopsis fecunda is achieved based on additional specimens from Yunnan Province, China. New features for the leaf morphology and pinnae arrangement of D. fecunda have been extended. The fossil record in China suggest that D. fecunda is a key species in the Northern Floristic Region (NFR) of China, spreading from the NFR to the Southern Floristic Region via the transitional zone in the Carnian and distributing in Yunnan in the Norian. In addition, the global tempo-spatial distribution pattern and the palaeoclimate implications of Danaeopsis are discussed. The genus Danaeopsis was distributed in Europe, Asia and even in Australia with warmer and humid, rarely semi-arid conditions in the Triassic. The wide-ranging distribution of Danaeopsis could be largely related to the palaeoclimatic pattern in the Triassic. [ABSTRACT FROM AUTHOR]

Lycophytes and ferns are the oldest terrestrial vascular plants, sensitive to climate change, and can act as an indicator of environmental change in the forest. However, knowledge about the way in which environmental factors influence diversity distribution of lycophytes and ferns in Northeast China still remains limited. Based on the latest PPGI classification, this study has taken lycophytes and ferns in Northeast China as the research object. Using county distribution information and environmental factor data, combining stepwise multiple regression (SMR) and geographically weighted regression (GWR), species diversity and environmental origin of lycophytes and ferns in Northeast China have been discussed. The results have shown that areas of high species diversity of lycophytes and ferns in Northeast China have mainly been concentrated in Changbai Mountains, Da Hinggan Mountains and Xiao Hinggan Mountains, and Changbai Mountains have been the most abundant. Precipitation of wettest quarter (Bio16), elevation range (ER), and forest area (FA) have been the three key environmental factors affecting the species diversity distribution. Bio16, as the most important factor, can further reveal the influence of special life history characteristics of lycophytes and ferns on species diversity. This study sheds light for the first time on the main environmental factors affecting the species diversity of lycophytes and ferns in Northeast China. [ABSTRACT FROM AUTHOR]

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Gongga Mountain is the highest peak of Hengduan Mountains and is an adequate site to study species diversity and the successive distribution of species along altitude. In this study we present an account of the species diversity and floristic characters of lycophytes and ferns in Gongga Mountain based on field survey, specimens identification, and literatures reviewing. The results are as follows:(1)A total of 316 species of 60 genera in 26 families of lycophytes and ferns were recognised in this study.(2)Of these species, six species are assessed to be rare and endangered and need special protection in China. They are Isoëtes hypsophila, Psilotum nudum, Alsophila spinulosa, Aleuritopteris albofusca, Polystichum glaciale and Lepisorus palmatopedatus.(3)Of the fern flora in this mountain, the largest four families are Dryopteridaceae(75 species), Polypodiaceae(56 species), Pteridaceae(54 species), and Athyriaceae(37 species); The largest four genera are Polystichum (45 species), Dryopteris(24 species), Athyrium (24 species), and Lepisorus(19 species).(4)Temperate species are the dominant floristic elements(286 species, 93.77%)in this mountain. With the ascending of the elevation from 1 000 to 3 000 m, the species diversity gradually increases, which reaches the highest at the zone between 2 000-3 000 m where 192 species(belonging to 60 genera in 20 families)were recorded, and above 3 000 m, the species diversity declines, with only four species of ferns found over 4 500 m. When viewing the floristic elements, the Sino-Himalaya species are found to be gradually increased along the ascension of elevations. [ABSTRACT FROM AUTHOR]

A megafossil flora (i.e., Shuicheng flora) has been collected from the Upper Permian Longtan Formation coal-bearing rock series in the Wangjiazhai coal district, Shuicheng county, western Guizhou Province, southwestern China. Shuicheng flora, as an important part of the late Permian Cathaysian flora in South China, thrived in warm and humid conditions after the eruption of the Emeishan basalt but disappeared during the end-Permian mass extinction event. Here the fossil plants including 13 species in 9 genera were systematically described and compared. Results of systematic taxonomic studies demonstrate that these fossil plants are dominated by ferns and pteridosperms, followed by some sphenopsids, ginkgophytes and lycopsids. Taphonomic analysis shows that these fossil plants are mainly dominated by parautochthonous burial and accompanied by a small number of heterochthonous burial. Meanwhile, the palaeoecological reconstruction of Shuicheng flora suggests that these plants including lepidodendrids presented tall trees, calamites presented trees, ferns and pteridosperms presented trees, small trees, shrub, microphanerophytes and herbaceous plants, and ginkgopsida presented trees grown on detrital substrates under warm and humid climatic conditions and constituted a portion of the terrestrial landscape in western Guizhou Province during the Wuchiapingian. [ABSTRACT FROM AUTHOR]

The Early Pennsylvanian land plant community is characterized by widespread forests consisting of lycopsids, ferns, and seeds fern in swampy wetlands. The contemporaneous palynological assemblages are mainly composed of spores of Lycospora spp., Densosporites spp., and Laevigatosporites spp. and monosaccate prepollen of Florinites spp. Taeniate bisaccate pollen appeared for the first time during the Early Pennsylvanian but never prevailed in the coeval palynological assemblages. Here, we report a taeniate bisaccate pollen‐dominated palynological assemblage from the Jiamuhe Formation of Well Ke 85 in the Zhongguai Uplift, northwestern Junggar Basin, Xinjiang. Nineteen miospore species belonging to 14 genera were identified from the assemblage. Based on their relative abundance, one assemblage is nominated informally as Calamospora breviradiata–Lunatisporites tersus (BT) assemblage. SIMS U–Pb geochronological analysis of zircons from two volcanic ash beds from the basal and upper parts of the formation yields weighted mean 206Pb/238U dates of 316.3 ± 2.2 Ma (MSWD = 1.2, n = 19) and 316.5 ± 2.8 Ma (MSWD = 0.85, n = 20) in an ascending order. A Bashkirian age is thus assigned to the BT assemblage. Our combined palynological and geochronological investigations reveal an early stage of the rise of conifers in the Kazakhstan Plate and offer a rare glimpse into the Early Pennsylvanian land vegetation in the subtropical area at the northern hemisphere. [ABSTRACT FROM AUTHOR]

Dipteris shenzhenensis, a new species of ferns from Shenzhen, Guangdong, southern China, is identified and described. It closely resembles D. chinensis but possesses several unique traits, such as long rhizome scales, castaneous stipe, and abaxially pale fronds with two fan-shaped fronds connected by a broad wing. Molecular evidence showed that D. shenzhenensis is allied to D. conjugata, whereas it has morphologically significant differences (P < 0.05) on the basis of quantitative trait statistical analysis. Overall, the morphological evidence, taken together with the result of cpDNA indicated that D. shenzhenensis is a distinct species. [ABSTRACT FROM AUTHOR]

Background and aims: Litter-derived dissolved organic carbon (DOC) biodegradation is critical to forest ecosystem structure and function. However, it is unclear whether mixing overstory and understory litter-derived DOC could produce non-additive effects on biodegradation in forests. Methods: We extracted DOC from leaf litter of two coniferous trees, four broadleaf trees, and four understory ferns in subtropical forests and used a laboratory incubation method to measure pure and mixed overstory and understory litter-derived DOC biodegradation. The purposes were to assess the interspecific patterns of litter-derived DOC biodegradation between overstory trees and understory ferns, and then examine the non-additive effects of mixing overstory and understory litter-derived DOC on biodegradation. Results: Litter-derived DOC biodegradation of understory ferns was comparable to that of overstory broadleaf trees, but higher than that of overstory coniferous trees. Mixing overstory and understory litter-derived DOC produced non-additive effects on biodegradation in all 24 DOC mixtures. Specifically, synergistic effects were observed in 22 DOC mixtures, and antagonistic effects occurred in the other two DOC mixtures. Non-additive effects on DOC biodegradation were positively related to the interspecific differences in DOC:dissolved total phosphorus ratio and DOC aromaticity, respectively, and exhibited no significant relationship with the interspecific differences in DOC:dissolved total nitrogen ratio. Conclusions: Non-additive effects are common during microbial degradation of overstory and understory litter-derived DOC mixtures, and trait dissimilarity among component DOC sources drives the directions and magnitudes of non-additive effects on biodegradation in subtropical forests. [ABSTRACT FROM AUTHOR]

Wetland parks play various ecological roles, including maintaining regional ecological balance, and connoting and compensating water sources. Taking Harbin Qunli National Urban Wetland Park as the research object, the diversity of plant resources in wetland parks is investigated and analyzed with the goal of providing a scientific basis for ecological restoration and the conservation and utilization of urban wetlands. Field survey, sampling and data collection methods were used to study the wetland plant resources and their life types (e.g., vines or shrubs), ecological types and distribution types. The study found 60 families, 129 genera and 160 species of wetland plants in Qunli National Urban Wetland Park, including 56 families, 123 genera and 151 species of angiosperms, which include 48 families, 101 genera and 127 species of dicotyledons and 8 families, 22 genera and 24 species of monocotyledons; 2 families, 2 genera and 3 species of ferns; and 2 families, 4 genera and 6 species of gymnosperms. The family composition is dominated by those families that included 10 or more species, and the dominant families are Compositae and Rosaceae. The genus composition is dominated by genera with four or more species present, and the dominant genera are Acer, Malus and Artemisia. Among the six life types, herbaceous plants are dominant, with a proportion of 62.50% of the species. The ecological types are divided into three categories: wet, mesophytic and aquatic plants, with wet plants accounting for the largest proportion, i.e., 56.25% of the total number of plant species. There are five distribution types of plant families and 10 types of the genera, with both families and genera dominated by the Northern Temperate types, so the flora has obvious temperate characteristics. [ABSTRACT FROM AUTHOR]

Aim: (1) To understand geographic patterns of species discovery by examining the effect of growth form, range size, and geographic distribution on discovery probability of vascular plant species in China; (2) to find out which taxa harbor the largest number of undiscovered species and where those species locate; and (3) to find out the determinants of province‐level mean discovery time and inventory completeness. Location: China. Methods: We compiled the discovery time and province‐level geographic distributions of ~31,000 vascular plant species described between 1753 and 2013 from Flora of China. We used a Cox proportional hazard model to determine the biological and geographic correlates of discovery probability. Accumulation curves of species discoveries were fitted by a logistic discovery model to estimate inventory completeness of different growth forms and of different provinces. We then used linear regression to identify the determinants of mean discovery time and beta regression to identify the determinants of inventory completeness. Results: We found that species with larger range size and distributed in northeastern part of China have a higher discovery probability. Coastal species were discovered earlier than inland species. Trees and shrubs of seed plants have the highest discovery probability while ferns have the lowest discovery probability. Herbs have the largest number of undiscovered species in China. Most undiscovered species will be found in southwest China, where three global biodiversity hot spots locate. Spatial patterns of mean discovery time and inventory completeness are mainly driven by the total number of species, human population density in an area, and latitude and longitude of a province. Main Conclusions: Socioeconomic factors primarily determine the discovery patterns of vascular plants in China. Undiscovered species are most likely to be narrow‐ranged, inconspicuous endemic species such as herbs and ferns, which are prone to extinctions and locate in biodiversity hot spots in southwestern China. [ABSTRACT FROM AUTHOR]

Aim: Previous studies have found strikingly different geographical patterns of phylogenetic diversity of gymnosperms and angiosperms, which have been suggested to result, in part, from the greater age of the former. To assess the effects of clade age on phylogenetic structure, we assessed phylodiversity patterns of pteridophytes (lycophytes and ferns), which combine ancient and modern lineages, across China. Location: China. Time period: Present day. Taxon: Pteridophytes. Methods: We divided China into 66 regions and collated species lists of pteridophytes for each region. We then related taxonomic and phylogenetic diversity, and their related metrics, to six climatic variables for pteridophytes as a whole and for different evolutionary clades. We examined the effect of spatial autocorrelation among regional floras on the results. Results: We found that when all pteridophytes or ferns were considered, the patterns resembled those of gymnosperms, presumably reflecting the effects of several ancient global mass extinctions and the relict distribution of old families. In contrast, when we considered only the modern Polypodiales radiation, which accounts for three‐quarters of current fern diversity and is about as old as the angiosperm radiation, we found a pattern similar to that of angiosperms. This pattern is consistent with the tropical niche conservatism hypothesis and suggests that both major groups of land plants have a broadly similar evolutionary trajectory, with most families originating in tropical conditions and few families adapting to cold and arid conditions. Main conclusions: Our study shows that the phylogenetic structures of more recently evolved and diversified clades of pteridophytes are fairly consistent with the tropical niche conservatism hypothesis, suggesting that the age of the taxon, its physiological adaptations and the global climatic changes that it experienced during its evolutionary history are reflected in the composition of current plant assemblages. [ABSTRACT FROM AUTHOR]

The Species Catalogue of China: Volume 1: Plants (SCCP) is a new, comprehensive, hardcopy inventory of Chinese higher plants that combines several datasets and references to recent taxonomic treatments. The database, with all attached additional information, is freely accessible via the internet (http://www.sp2000.org.cn/) and on CD‐ROM, and will be updated yearly. It includes bryophytes (157 families, 599 genera, and 3167 specific and infraspecific taxa), lycophytes and ferns (41 families, 181 genera, and 2336 specific and infraspecific taxa), gymnosperms (10 families, 45 genera, and 311 specific and infraspecific taxa), and angiosperms (270 families, 3227 genera, and 35 873 specific and infraspecific taxa); in total 478 families, 4052 genera, and 41 687 specific and infraspecific taxa. Several other important statistics can also be drawn from the database, such as the distribution pattern of the four major groups of higher plants, as well as number of endemic and naturalized or cultivated genera/taxa. Entries in SCCP are also compared with Flora of China, and Flora reipublicae popularis Sinicae at the genus level. The SCCP will not only be a useful reference for floristic or biodiversity studies in China, but will also serve as a key resource to direct action and monitor progress. It is intended to be a useful resource for achieving Target 1 of the Global Strategy for Plant Conservation (GSPC). [ABSTRACT FROM AUTHOR]

Spatial genetic variation involves spatial genetic structure (SGS) and genetic diversity is important genetic features of plants. We first evaluated spatial genetic structure (SGS) and genetic diversity among four populations of Alsophila gigantea from Hainan Island, China, using inter-simple sequence repeat (ISSR) markers. Significant but weak FSGS was found in A. gigantea . High genetic diversity was identified at the species level and the population level. AMOVA analysis revealed a low level of genetic differentiation among the four populations with high gene flow. Mantel test showed no significant correlation between genetic distance and geographic distance. It was found that association between annual mean temperature and annual precipitation with FSGS. Combined with these spatial genetic variation, abundant precipitation and suitable temperature create a stable environment for A. gigantea in Hainan Island, which allows the fern to expand rapidly during the LGM. These results further emphasized the role of outcrossing, and history and environmental factors in the evolution of A. gigantea . This study also provided new insights on in local adaptation of A. gigantea to environmental fluctuations, and available genetic data to enhance the conservation for relict tree ferns. [ABSTRACT FROM AUTHOR]

Brainea insignis is the only species in the genus Brainea. It is widely distributed in the Asia and Australia continents, but usually in small, fragmented populations. Owing to its sensitivity towards habitat changes and human disturbance, the population of this fern is deteriorating. At present, it is classified as an endangered species in China. In this study, we assessed the forest diversity and vitality status of B. insignis in its natural habitat. A total of 63 vascular plant species belonging to 55 genera of 40 families were recorded in the 1200-m2 study plot. The Raunkiaer's frequency index indicated that B. insignis was experiencing a decline in stand size and structure although the overall level of vitality was 18.58. One-way ANOVA revealed that significant differences were detected between the basal diameter, tree height, crown size, and number of leaves of B. insignis in the study plot, but not between tree height and number of leaves. Proper conservation management is requisite to ensure continuous survival of this relict species in the wild despite eqinterference from evolution and urbanisation from mankind. [ABSTRACT FROM AUTHOR]

• Test correlations in species richness between 10 taxa from 361 nature reserves in China. • Assessed the relative importance of competing mechanisms hypothesized to promote indicator taxa correlations. • No single taxon is useful for indicating all other taxa; ferns have the potential to predict reptile and amphibian richness. • Temperature and water availability are the most important factor for predicting species richness in most of the studied taxa. Indicator taxa have been widely used in biological conservation when data on the taxa of conservation interest are lacking. However, most studies have focused on common taxa (e.g., vascular plants, birds, reptiles, amphibians, and mammals) and found little consistent correlation between taxa. In this study, we extended the investigation to cover 10 taxonomic groups from 361 nature reserves in China. We assessed the strength of competing mechanisms hypothesized to promote indicator taxa correlations. We detected significant positive correlations in species richness among most of the 10 taxonomic groups except for macrofungi-insect and bryophyte-bird pairs. Yet, we found no single taxon satisfying the criteria to be used as an indicator for other taxa, although angiosperms had the potential to predict species richness of several other groups (e.g., ferns, gymnosperms, mammals, reptiles, amphibians), and ferns were useful for indicating reptiles and amphibians. Macrofungi and insects are the two groups that cannot be effectively indicated by any other groups. We also found that energy and climatic stability played the most significant role in regulating species richness of most study taxa, and possibly their between-taxon correlations. Our study provides new evidence for understanding cross-taxon congruence and the underlying mechanisms in the nature reserves of China. [ABSTRACT FROM AUTHOR]

The Xiangjiang River region witnessed intensive economic and cultural activities in the past two millennia. In particular, the thriving ceramic production during the Tang Dynasty had a far-reaching impact on the local environment. However, the lack of palaeo-ecological and archaeological research at and around historical production sites hinders our understanding on the relationship between human activities and vegetation dynamics in this region. We examined the Shizhuping (SZP) profile at the Tongguan kilns, and conducted palynological analysis to reconstruct vegetation dynamics in response to human activities in the study area over the past 1300 years. Our results showed that mixed evergreen and deciduous broadleaf forest, which was primarily composed of Cyclobalanopsis and Quercus, was the dominant vegetation type at ca. 1300 a BP. From 1300 to 950 a BP, the percentage of arboreal pollen reduced considerably, while the percentage of pollen of herbaceous plant species including Poaceae, Artemisia , and Aster types increased significantly. The latter might be attributed to an increasingly arid climate, and intensified human activities during this period. Increased fuel demand due to the thriving porcelain production led to large scale wood logging and deforestation. During 950–600 a BP the percentage of pollen of plant species growing in wet habitats including hydrophytes (mainly Cyperaceae and Typha), ferns and freshwater algae increased significantly, which suggested a relatively wet condition and expansion of wetlands. However, due to the severe devegetation and the expansion of cultivated lands caused by rapid population growth from the previous phase, vegetation in this area did not experience an evident restoration under the favorable climate at this stage. Since 600 a BP, the content of Pinus increased significantly, exceeding that of broadleaf trees, which demonstrated that secondary pine forest was established in the mountain and/or hills around the Tongguan kilns. In addition, the increase in the percentages of human-related pollen types reflected the growing anthropogenic impact on the environment. We concluded that the native vegetation in the Tongguan kilns area had been severely affected by human activities especially porcelain production activity and agricultural reclamation since 1300 a BP, resulting in a deteriorating regional human-land relationship. [ABSTRACT FROM AUTHOR]

Understory vegetation has an important impact on soil organic carbon (SOC) accumulation. However, little is known about how understory vegetation alters soil microbial community composition and how microbial diversity contributes to SOC chemical composition and persistence during subtropical forest restoration. In this study, removal treatments of an understory fern (Dicranopteris dichotoma) were carried out within pine (Pinus massoniana) plantations restored in different years in subtropical China. Soil microbial community composition and microbial diversity were measured using phospholipid fatty acids (PLFAs) biomarkers and high-throughput sequencing, respectively. The chemical composition of SOC was also measured via solid-state 13 C nuclear magnetic resonance ( 13 C NMR). Our results showed that fern removal decreased alkyl C by 4.2 % but increased O-alkyl C by 15.6 % on average, leading to a decline of alkyl C/O-alkyl C ratio, suggesting altered chemical composition of SOC and lowered SOC recalcitrance without fern. Fern removal significantly lowered the fungi-to-bacteria ratio, and it also reduced fungal and bacterial diversity. Partial correlation analysis revealed that soil nitrogen availability was a key factor influencing microbial diversity. Bacterial diversity showed a close relationship with the Alkyl C/O-alkyl C ratio following fern removal. Furthermore, the microbial community structure and bacterial diversity were responsible for 18 % and 55 % of the explained variance in the chemical composition of SOC, respectively. Taken together, these analyses jointly suggest that bacterial diversity exerts a greater role than microbial community structure in supporting SOC persistence during understory fern removal. Our study emphasizes the significance of understory ferns in supporting microbial abundance and diversity as a means of altering SOC persistence during subtropical forest restoration., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Blechnum orientale L. is a traditional, medicinal fern found in China. To assess the characteristics of heavy metals and As accumulation, the fronds, roots, and the rooting soils of this fern were sampled from urban, suburban, and rural woodlands across Guangdong Province in southern China. The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn in both the fern and its rooting soils were separately detected by ICP-MS. Contamination levels of woodland rooting soils were also assessed using both a single pollution index and the Nemerow pollution index. Both the metal concentrations and the pollution index showed that soils from urban, suburban, and even rural woodlands were adversely contaminated by As, Cd, Hg, and Pb. Based on transfer factor, B. orientale had good translocation of As, Hg, and Mn, but poor translocation of Cd, Cr, Ni, Cu, Ni, Pb, and Zn from the roots to the fronds. This result suggests that this fern could be an excluder to latter metals. Despite the significantly higher levels of metals in the roots as compared with the fronds, the low bioaccumulation factor suggests that this fern has a weak capacity for metal accumulation. [ABSTRACT FROM AUTHOR]

Isoetes sinensis Palmer is a critically endangered, first-class protected plant in China. Until now, researchers have primarily focused on the ultrastructure, phylogeny, and transcriptomes of the plant. However, flavonoid profiles and bioactivity of I. sinensis have not been extensively investigated. To develop the endangered I. sinensis for edible and medicinal purposes, flavonoid content, chemical constitution, and antioxidant activities were investigated in this study. Results revealed the following. 1) The total flavonoid content was determined as 10.74 ± 0.25 mg/g., 2) Antioxidant activities were stronger than most ferns, especially ABTS free radical scavenging activities. 3) Four flavones, containing apigenin, apigenin-7-glucuronide, acacetin-7-O-glcopyranoside, and homoplantageninisoetin; four flavonols, namely, isoetin, kaempferol-3-O-glucoside, quercetin-3-O-[6"-O-(3-hydroxy-3-methylglutaryl)-β-D-glucopyranoside], and limocitrin-Neo; one prodelphinidin (procyanidins;) and one nothofagin (dihydrochalcone) were tentatively identified in the mass spectrometry-DAD (254nm) chromatograms. This study was the first to report on flavonoid content and antioxidant activities of I. sinensis. Stronger antioxidant activity and flavonoid content suggests that the endangered I. sinensis is an important and potentially edible and medicinal plant. [ABSTRACT FROM AUTHOR]

Ａｃｃｏｒｄｉｎｇ ｔｏ ｔｈｅ ｎｅｗ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍ ｏｆ ｉｎｔｅｒｎａｔｉｏｎａｌ Ｌｙｃｏｐｏｄｓ ａｎｄ Ｆｅｒｎｓ ｉｎ ｔｈｅ Ｆｌｏｒａ ｏｆ Ｃｈｉｎａꎬ Ｐｏｌｙｐｏ- ｄｉａｃｅａｅ ｉｎｃｌｕｄｅｓ ｍｏｒｅ ｔｈａｎ ２０ ｇｅｎｕｓ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ ｉｎ ｔｈｅ Ｑｉｎｒｅｎｃｈａｎｇ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍꎬ ａｎｄ ａｌｓｏ ｉｎｃｌｕｄｅｓ ｉｎｄｅ- ｐｅｎｄｅｎｔ ｆａｍｉｌｉｅｓ ｓｕｃｈ ａｓ Ｄｒｙｎａｒｉａｃｅａｅ ａｎｄ Ｐｌａｔｙｃｅｒｉａｃｅａｅ. Ｔｈｅ ｎｅｗ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ ｉｎ ｔｈｅ Ｆｌｏｒａ ｏｆ Ｃｈｉｎａ ｗｉｔｈ ｍａｎｙ ｉｓｓｕｅｓ ｎｅｅｄｓ ｆｕｒｔｈｅｒ ｉｎｖｅｓｔｉｇａｔｉｏｎ ａｎｄ ｃｌａｓｓｉｆｉｃａｔｉｏｎ. Ｈｅｒｅ ｗｅ ｉｎｖｅｓｔｉｇａｔｅｄ ｔｈｅ ｓｐｏｒｅ ｍｏｒｐｈｏｌｏｇｙ ａｎｄ ｐｅｒｉｓｐｏｒｅ ｏｒｎａｍｅｎｔａｔｉｏｎ ｓｕｂｍｉｃｒｏｓｃｏｐｉｃ ｓｔｒｕｃｔｕｒｅ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ ｆｒｏｍ Ｓｈａｎｄｏｎｇ Ｐｒｏｖｉｎｃｅ ｕｓｉｎｇ ｓｃａｎｎｉｎｇ ｅｌｅｃｔｒｏｎ ｍｉ- ｃｒｏｓｃｏｐｙ (ＳＥＭ). Ｔｈｉｓ ｉｓ ｔｈｅ ｆｉｒｓｔ ｐａｌｙｎｏｌｏｇｉｃａｌ ｓｔｕｄｙ ｂａｓｅｄ ｏｎ ｔｈｅ ｎｅｗ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ. Ｔｈｅ ｒｅ- ｓｕｌｔｓ ｗｅｒｅ ａｓ ｆｏｌｌｏｗｓ: Ｓｐｏｒｅｓ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ ｗｅｒｅ ｒｅｎｉｆｏｒｍꎬ ｂｉｌａｔｅｒａｌｌｙ ｓｙｍｍｅｔｒｉｃａｌꎬ ｐｏｓｓｅｓｓｉｎｇ ａ ｐｅｒｉｓｐｏｒｅ ｗｉｔｈ ｓｔａｂｌｅ ｏｒｎａｍｅｎｔａｔｉｏｎ ｗｉｔｈｉｎ ｓｐｅｃｉｅｓ ａｎｄ ｃｌｅａｒ ｄｉｓｔｉｎｃｔｉｏｎｓ ｂｅｔｗｅｅｎ ｓｕｂｆａｍｉｌｙꎬ ｇｅｎｕｓ ａｎｄ ｓｐｅｃｉｅｓ. Ｔｈｅ ｐａｌｙｎｏｌｏｇｉｃａｌ ｓｔｕｄｉｅｓ ｓｕｐ- ｐｏｒｔｅｄ ｔｗｏ ｏｆ ｔｈｅ ｓｕｂｆａｍｉｌｉｅｓ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ-Ｄｒｙｎａｒｉａ ａｎｄ Ｐｌａｔｙｃｅｒｉｕｍ ｄｅｌｉｎｅａｔｅｄ ｉｎ ｔｈｅ ＦＯＣ. Ｉｎ ａｄｄｉｔｉｏｎꎬ ｔｈｅ ｐｅｒｉｓ- ｐｏｒｅ ｏｒｎａｍｅｎｔａｔｉｏｎ ｃｏｍｂｉｎｅｄ ｗｉｔｈ ｌｅａｆ ｍｏｒｐｈｏｌｏｇｉｃａｌ ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ ｓｈｏｗｅｄ ｔｈａｔ Ｐｈｙｍａｔｏｐｔｅｒｉｓ ｓｈａｎｄｏｎｇｅｎｓｉｓ Ｊ. Ｘ. Ｌｉ ｅｔ Ｃ. Ｙ. Ｗａｎｇ ｗａｓ ａ ｄｉｓｔｉｎｃｔ ｓｐｅｃｉｅｓꎬ ａｎｄ ｓｈｏｕｌｄ ｂｅ ｒｅｓｔｏｒｅｄ ｔｏ ａ ｓｐｅｃｉｅｓ ｌｅｖｅｌ ｐｏｓｉｔｉｏｎ ｒａｔｈｅｒ ｔｈａｎ ｉｎｃｏｒｐｏｒａｔｅｄ ｗｉｔｈ Ｐ. ｈａｓｔａｔａ (Ｔｈｕｎｂ.) Ｐｉｃ. Ｓｅｒｍ.ꎬ ｎｏｔ ｒｅｇａｒｄ ａｓ Ｐｈｙｍａｔｏｐｔｅｒｉｓ ｂｕｔ ａｓ ａ ｎｅｗ ｃｏｍｂｉｎａｔｉｏｎ Ｓｅｌｌｉｇｕｅａ ｓｈａｎｄｏｎｇｅｎｓｉｓ (Ｊ. Ｘ. Ｌｉ ｅｔ Ｃ. Ｙ. Ｗａｎｇ) Ｊ. Ｘ. Ｌｉ ＆ Ｘ. Ｊ. Ｌｉꎬ ｃｏｍｂ. ｎｏｖ. ａｃｃｏｒｄｉｎｇ ｔｏ ｔｈｅ Ｉｎｔｅｒｎａｔｉｏｎａｌ Ｃｏｄｅ ｏｆ Ｂｏｔａｎｉｃａｌ Ｎｏｍｅｎｃｌａｔｕｒｅ ａｎｄ ｔｈｅ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍ ｏｆ Ｆｌｏｒａ ｏｆ Ｃｈｉｎａ. Ｏｕｒ ｓｔｕｄｙ ｎｏｔ ｏｎｌｙ ｈａｓ ａｃｃｕｍｕｌａｔｅｄ ｎｅｗ ｉｎｆｏｒｍａｔｉｏｎ ｆｏｒ ｔｈｅ ｐａｌｙｎｏｌｏｇｙ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅꎬ ｂｕｔ ａｌｓｏ ｐｒｏｖｉｄｅｓ ａ ｐａｌｙｎｏｌｏｇｉｃａｌ ｂａｓｉｓ ｆｏｒ ｉｔｓ ｎｅｗ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍꎬ ｗｈｉｃｈ ｉｓ ｃｏｎｓｉｓｔｅｎｔ ｗｉｔｈ ｍｏｌｅｃｕ- ｌａｒ ａｎａｌｙｓｉｓꎬ ａｎｄ ｃｏｎｆｉｒｍｓ ｔｈｅ ｒａｔｉｏｎａｌｉｔｙ ｏｆ ｔｈｅ ｎｅｗ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｓｙｓｔｅｍ ｏｆ Ｐｏｌｙｐｏｄｉａｃｅａｅ ａｎｄ ｉｔｓ ｓｕｂｆａｍｉｌｉｅｓ. [ABSTRACT FROM AUTHOR]

The genus Coniopteris was a dominate member of most Middle Jurassic floras globally. Strata in northern Xinjiang Province are well-known for containing abundant fern and ginkgo fossils, especially Coniopteris, usually identified as the Coniopteris-Phoenicopsis flora. We report a new species named Coniopteris sandaolingensis X. C. Yuan et B. N. Sun sp. nov in this paper which was collected from the Xishanyao Formation within the Turpan-Hami Basin. This species is recognized and described based on the architecture of its fronds and reproductive organ features. The fertile pinnae in this species are also slightly contracted, which suggests that currently known specimens belong to either Coniopteris or Eboracia to some extent, while its characteristic cup-like indusia show that it belongs to Coniopteris. This species is unique, however, because the first pinnule on the basiscopic side is forked into two equal lanceolate lobes. The results of our comparisons based on fossil Dicksoniaceae lead us to conclude that both present fossil and C. bella are likely transitional species that might provide insights into exactly how Coniopteris has evolved into other genera. The fossils discussed here led us to infer that the climate during the early Middle Jurassic of Sandaoling is warm and humid. [ABSTRACT FROM AUTHOR]

The establishment of arbuscular mycorrhizal fungi (AMF) symbiosis is generally considered an important pathway that assists ferns in their adaption to a variable environment in the forest ecosystem. However, how both fern species and seasonal variation affect the symbiotic characteristics and AMF community structure remains largely unknown. In this study, the AMF colonization status of 19 fern species in the Heishiding Nature Reserve located in south China was assessed. The effects of seasons on AMF colonization and community structure were also determined. The results showed that both seasons and species significantly affected AMF colonization rate (1.88–56.03 %) and spore density (94–546/25 g dry soil). In addition, according to principal component analysis, in spring, AMF colonization and spore density differed considerably from other seasons. The total AMF sequences detected in spring were significantly higher than in winter (p < 0.05). Glomus was the dominant genus, accounting for >75 % of all sequences. The AMF Chao1 and Faith PD indexes of Blechnum orientale Linn as well as the Shannon and Simpson indexes of Selaginella doederleinii Hieron were significantly higher in spring than in winter (p < 0.05). According to partial least squares path modeling, season had a significant influence on AMF colonization by varying the AMF alpha diversity rather than their community composition. Notably, network analysis showed that seasonal variation induced differences in AMF network structure, keystone taxa, and the number of links between species. This study highlights the symbiotic relationship between ferns and AMF in different seasons. The results provide novel insights on terrestrial ecosystem management and fern conservation from the perspective of plant-AM symbiosis. [Display omitted] • Three typical AM structures could be observed in all 19 ferns. • Species and season affected AMF colonization by altering AMF alpha diversity. • Distinct differences in AMF co-occurrence patterns were observed among seasons. [ABSTRACT FROM AUTHOR]

The issue of ion-adsorption type rare earth deposits (IADs) in urban areas of South China has garnered significant attention due to its environmental implications. Hyperaccumulator-based phytoremediation is a potentially effective solution for reducing the environmental impact of IADs in urban areas, particularly using ferns as they are known to be REE hyperaccumulators. However, the ability of different fern species to accumulate REEs in urban areas remains unknown. In this study, four fern species, including known hyperaccumulators (Dicranopteris linearis and Blechnum orientale) and other ferns (Pteris ensiformis and Cibotium barometz), were studied to investigate their REE accumulation abilities in the Guangzhou urban area. The aboveground parts of Dicranopteris linearis (848.7 μg g -1 ) and Blechum orientale (1046.8 μg g -1 ) have been found to accumulate high concentrations of REEs, demonstrating they probably can be applied for phytoremediation in the natural environments. Despite having lower REE concentrations than REE hyperaccumulators, Pteris ensiformis and Cibotium barometz still probably have the function as phytostabilizers in urban areas, as REEs can be enriched in their roots beyond the normal levels of plants. The enrichment of REEs in ferns is influenced by the availability of various nutrients (K, Ca, Fe, and P), which probably can be associated with different growth processes. The four fern species show LREE enrichment, moderate Eu anomalies and different Ce anomalies. It is difficult to absorb and transfer Ce to the aboveground parts of Blechnum orientale and Cibotium barometz. The study also identified selective enrichment of Ce in Pteris ensiformis, which has potential for comprehensive extraction of REEs when combined with other REE hyperaccumulators. REE fractionations are probably determined by the specific characteristics of different fern parts. Overall, these findings provide insights for addressing potential environmental problems related to IADs and offer guidelines for phytoremediation technology in addressing high REE levels in urban areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The complicated nomenclatural history of the extinct fossil‐genera Acitheca and Strephopteris (fertile foliage) and Polymorphopteris (sterile foliage), established for fossil ferns (Marattiopsida), is reviewed and corrected with new bibliographic and historical data. Strephopteris as a generic name established for fertile foliage of Acitheca‐type has priority, but due to the long and widespread use of Acitheca it was recently proposed to reject it in favour of the established name Acitheca. Since Acitheca as a fossil‐genus was established for distinctive fertile foliage, but its currently accepted type, A. polymorpha (≡ Pecopteris polymorpha), was founded on sterile foliage, it is proposed to reject this type and return to the earlier concept of Sterzel who thought that Acitheca was typified by the fossil‐species Scolecopteris conspicua, based on fertile foliage. This procedure requires official conservation of the type. Correction of the type allows continuing the current use of another fossil‐genus, Polymorphopteris, which was inadvertently validated on the same type as Acitheca. The legitimization of the fossil‐genus Polymorphopteris, based on sterile foliage only, will stabilize the current established systematics of fossil marattiopsid remains, for which no fertile organs are known. Since Scolecopteris conspicua, when established as a fertile counterpart of sterile foliage known as Pecopteris polymorpha, originally included two unrelated archetypes of fertile foliage, known as compressions and petrifactions, the typification of the fossil‐species by fossil specimens known as compressions allows continued use of Acitheca as a distinct fossil‐genus for fertile foliage as compressions. The petrifactions formerly attributed to A. polymorpha from younger sediments (Lower Permian) of France are re‐considered as a distinct fossil‐species, Scolecopteris renaultii sp. nov. The formerly not validly published fossil‐genus Bifariusotheca for Acitheca‐like fossils from the Permian of China is validated. Kamatheca is validated for the aberrant Angaridan fossil‐species, Acitheca gigantea. Nine not validly published fossil‐species of Polymorphopteris are validated to follow modern circumscription of the fossil‐genus: Polymorphopteris cistii comb. nov., P. gothanii comb. nov., P. integra comb. nov., P. magdalenae sp. nov., P. multifurcata comb. nov., P. oblongifolia comb. nov., P. pseudobucklandii comb. nov., P. pseudointegra comb. nov., and P. wagneri sp. nov. Callipteridium subelegans and Scolecopteris conspicua are neotypified; Acitheca isomorpha and Pecopteris cistii are lectotypified. As an addition to Taxonomic literature II records, the precise dates of publication of the taxonomic works of Germar's Versteinerungen (1844–1853) and Schimper & Schenk's Palaeophytologie (1879–1890) are established for the first time. [ABSTRACT FROM AUTHOR]

We used pollen and grain-size data from a peat bog in Xiansan, Fujian Province, southeastern China, to reconstruct a high-resolution record of vegetation change, climatic dynamics, and human impact over the last 1330 cal BP. During 1330–1200 cal BP, we infer the existence of a swamp bog with dense cypress forests, based on dominant Cupressaceae pollen, suggesting cold and dry conditions during this early period. Fine-grained sediment and higher percentages of wetland pollen and fern spores suggest intermittent-lake conditions, indicating a wet Medieval Warm Period (MWP; 1200–730 cal BP). The increase in coniferous forest and montane shrub-meadow pollen indicate a cold and dry climate during the early to mid-Little Ice Age (LIA; 730–370 cal BP), but coarse-grained sediments associated with more abundant wetland taxa pollen indicate a shallower intermittent-lake landscape, reflecting relatively humid periods during 620–560 cal BP and 400–450 cal BP. During the last 370 cal BP, a rapid increase in the secondary forest component and a gradual decrease in the pollen-inferred floristic diversity index suggest that the natural vegetation was converted to secondary vegetation, as a result of severe anthropogenic disturbance in the montane region of Fujian Province. The reconstructed regional precipitation trend prior to this period was mainly correlated with East Asian summer monsoon (EASM) intensity, which is related to variation in solar irradiation. [ABSTRACT FROM AUTHOR]

The Chinese occurrences of the marattioid fern genus Christensenia have been considered as requiring protection because of its extreme rarity and very small population size. Here, we explored different biological aspects to enable protection of these rare ferns, well known as Mesozoic living fossils. Firstly, we documented the cytology of the Chinese occurrences for the first time. This is the second tetraploid record of Christensenia worth for further studies to confirm its taxonomic status. Secondly, we obtained the first complete plastid genome of this genus, which confirmed the proposed conservatism of the plastid genome structure in marattioid ferns. By comparing the chloroplast genome with other marattioids, we identified several candidate regions to develop highly variable markers to investigate the intra-species diversity of marattioid ferns. Thirdly, phylogenetic analyses of rbcL sequences implied that there are at least two distinct species of Christensenia. Finally, we re-assessed the conservation status of Christensenia in the context of its local and global distribution by assessing specimen information extracted from publications and digitized voucher information. This assessment confirmed the need to obtain more accurate information about the distribution of this genus to assess the status incorporating the disjunct distribution from southern China and India in the North towards the Solomon Islands in the South. [ABSTRACT FROM AUTHOR]

Our understanding of the flora of China has greatly improved during the last 100 years but effective management of the rich biodiversity and unique natural resources requires resolving the taxonomic limitations of existing treatments. Here, we focus on the epiphytic genus Scleroglossum with special emphasis on the occurrences in Hainan and Yunnan of mainland China. By combining fieldwork, herbarium studies, and DNA barcoding we test the hypothesis that this genus is represented by more than one species in China. Our integrative results show the Yunnan accessions are distinct from those in Hainan in both phenotypic and genotypic variation. The Yunnan accessions belong to S. pusillum, whereas the Hainan accessions represent a distinct species displaying the morphological characteristics of S. sulcatum. Genotypic evidence suggests the occurrence of cryptic diversity among accessions with the morphology of S. sulcatum. In summary, the study contributes to the crucial assessment of the plant diversity in Yunnan and illustrates the importance of integrating collection efforts and DNA barcoding approaches to enable effective assessment of the epiphytic diversity of Yunnan. [ABSTRACT FROM AUTHOR]

Fine roots of plants play an important role in terrestrial ecosystems. There is a close association between the anatomical characteristics and physiological and ecological functions of plants, but we still have a very limited knowledge of anatomical traits. For example, (1) we do not know if herbs and grasses have anatomical patterns similar to those of woody plants, and (2) the variation among different woody plants in the same ecosystem is unclear. In the present study, we analysed the anatomical structures of the fine root systems of various groups of vascular plants (ferns, eudicot herbs, monocots and woody plants) from the same ecosystem (a natural secondary forest on Mao'er Mountain, Heilongjiang, China) to answer the following questions: (1) How does the anatomy of the fine roots change with root order in various plant groups in the same ecosystem? (2) What is the pattern of variation within group? The results show that anatomical traits can be divided into 3 categories: traits that indicate the root capacity to transport resource along the root (stele diameter, xylem cell diameter and xylem cell area); traits that indicate absorptive capacity cortical thickness, (the number of cortical cell layers and the diameter of cortical cells); and traits that are integrated indicators (diameter and the stele to root diameter ratio). The traits indicate the root capacity to transport resource along the root order is generally similar among groups, but absorptive capacity is very different. The shift in function is the main factor influencing the fine root anatomy. Some traits show large variation within groups, but the variations in other traits are small. The traits indicate that the lower-order roots (absorbing roots) in distinct groups are of the first one or two root order in ferns, the first two or three orders in eudicot herbs, the first (only two root orders) or first two orders (more than three root orders) in monocots and the first four or five root orders in woody plants and the other roots are higher-order roots (transport roots). The result will helpful to understand the similarities and differences among groups and the physiological and ecological functions of plant roots. [ABSTRACT FROM AUTHOR]

Species data from 249 National Nature Reserves in China were used to identify potential underlying drivers of latitudinal gradients in plant diversity. We used generalized linear models to assess correlations between predictor and plant species richness. Variance partitioning was then used to decompose the variation in plant richness into different taxonomic levels among the three groups of predictors (i.e., climate, habitat and animal). We found that species richness showed significant latitudinal trends in richness (p < 0.001). This remained true when examining gymnosperms, angiosperms and ferns individually. Climate and habitat variables explained more variation in richness across different plant groups than did animal richness. Annual precipitation was the best climate variable across different taxonomic plants groups, and soil pH and elevation range were the best habitat variables across different taxonomic plant groups. The independent effects of habitat variables were higher than that of climate and animal variables across different taxonomic plant groups. Finally, climate, habitat heterogeneity, and animal richness explain 48.8% of the variation in total species richness, 28.2% in gymnosperm richness, 44.2% in angiosperm richness, and 38.9% in fern richness. [ABSTRACT FROM AUTHOR]

• Restoration of degraded lands increases microbial C use efficiency and C storage. • Removing understory ferns decreases the quality of litter inputs to soils and microbial C use efficiency. • Fern removal decreases total soil respiration in a young restored pine forest. • Litter quality exerts a greater role than litter quantity in SOC dynamics. • Understory ferns promotes SOC accumulation in restored pine forests. When reforesting degraded lands, understory ferns can take root and cover the forest floor, which can change the quality and quantity of litter added to soils. However, it is unclear how ferns and the ongoing succession of trees impact soil organic carbon (SOC) dynamics. Here, we established experimental sites in Masson pine (Pinus massoniana) stands for understanding the underlying mechanisms of how ferns affect SOC stock and soil respiration (R s) in subtropical China. The established three pine stands covered with ferns (Dicranopteris dichotoma (Thunb.) Berhn.) were used to represent a 37-year restoration sequence: two restored sites with vegetation cover (VC) established in 1984 and 2002 (referred to VC-1984 and VC-2002), and an unrestored site (VC-0). In August 2014, two treatments were set i.e., ferns were retained in half area of the sites ("control"), and continuously removed ferns from the other half ("fern removal") for seven years. Our results showed that fern removal significantly decreased R s by 25.8% in VC-2002 compared to the control over a three-year period from 2015 to 2018, but did not significantly affect R s in VC-0 and VC-1984. We found that fern removal decreased fine root biomass by 50.4% in VC-0, 31.4% in VC-2002, and 54.7% in VC-1984 in 2019, with seven-year averaged SOC stocks decreased by 37.2%, 13.9%, and 22.7% in VC-0, VC-2002, and VC-1984, respectively. Moreover, fern removal significantly increased carbon- and nitrogen-degrading enzyme activities and decreased microbial carbon use efficiency, suggesting that fern removal may increase SOC decomposition. Taken together, we concluded that fern removal may increase SOC-derived CO 2 efflux counteracting the reduced root respiration in VC-0 and VC-1984 but not in VC-2002, leading to a divergent response of R s to understory fern removal. Our study emphasizes the necessity of incorporating understory plants regulates SOC decomposition and accumulation in assessing forest recovery effects on soil carbon cycling. [ABSTRACT FROM AUTHOR]