Caves In China Research Articles

NEW CAVERNICOLOUS SPECIES OF THE GENUS CHALLIA BURR, 1904 (DERMAPTERA: PYGIDICRANIDAE, CHALLIINAE) FROM CHINA

A new species of the genus Challia Burr, 1904 (Dermaptera: Pygidicranidae, Challiinae), Challia guilinensis sp. n., is described and illustrated based on male from a karst cave in China. The new species differs from the congeners by the morphology of forceps and genitalia. Holotype is deposited in the Insect Collection of Jiangsu University of Science and Technology, Jiangsu Province, China.

Balitora anlongensis, the first cavefish species of the genus Balitora (Teleostei, Balitoridae) from Guizhou Province, southwest China

This work describes a new species, Balitora anlongensissp. nov., collected from a cave at Xinglong Town, Anlong County, Guzihou, China. Phylogenetic trees reconstructed based on two mitochondrial and three nuclear genes show that the new species represents an independent evolutionary lineage with large genetic differences, 7.1%–12.0% in mitochondrial gene cytochrome b and 9.2%–12.1% in cytochrome oxidase subunit 1, from congeners. Morphologically, the new species can be distinguished from the 18 species currently assigned to the genus Balitora by a combination of characters, most clearly by having two pairs of maxillary barbels; 8½ branched dorsal-fin rays; 5½ branched anal-fin rays; pectoral fin not reaching pelvic fin origin; dorsal-fin origin in front of pelvic fin origin; eye small (eye diameter approximately equal to outer maxillary barbel length); and fins lacking pigment in live fish. The new species represents the first record of Balitora inhabiting caves in China and increases the number of species in the genus Balitora in its present concept from 18 to 19. The study suggests that more evidence is needed to further clarify the taxonomic composition of the genus Balitora.

Feihu Dong, a New Hotspot Cave of Subterranean Biodiversity from China

China is a country with abundant karst landscapes, but research on cave biodiversity is still limited. Currently, only Ganxiao Dong, located in Huanjiang, Guangxi, has been reported as a hotspot for cave biodiversity. Many of the world’s most troglomorphic species in the major groups of cave animals have been recently discovered in China, making the existence of many more hotspots in the country likely. Feihu Dong, one of these potential hotspot caves, has been systematically investigated to complement a preliminary species list of 1995, leading to the discovery of 62 species of animals from the cave. Among them, 27 are considered troglobionts or stygobionts, 26 are considered troglophiles or stygophiles, and nine are classified as trogloxenes or stygoxenes. Research on the cave biodiversity of Feihu Dong has demonstrated that it currently holds the highest number of known cave animal species in China. Among the most remarkable features of this fauna is the co-occurrence of five species of cave-obligate beetles, all modified for cave life. The biological survey was limited to a small part of the cave. Several habitats (like guano) have not been investigated so far, and several important cave groups have been insufficiently or not sampled (like Ostracoda). Meanwhile, the system increases in length with each new caving expedition. Further discoveries of cave organisms in Feihu Dong are therefore expected. As Feihu Dong and Ganxiao Dong are the only caves in China that have been extensively studied for a large range of organisms, and as they are located in karstic areas that are similar in richness to other regions of southern China, it can be confidently assumed that several other caves of high biodiversity will be discovered in the coming years.

A newly recorded genus with description of a new cave-dwelling species of Flagelliphantes (Araneae, Linyphiidae) from northeastern China.

The genus Flagelliphantes Saaristo & Tanasevitch, 1996 was proposed by Saaristo & Tanasevitch, 1996 to accommodate three ex-Lepthyphantes species distributed in northern Eurasia. Male Flagelliphantes are easlily recognised by having a hood-shaped thumb on the embolus. The females have a long, S-shaped scape and the posterior median plate of the epigyne is grossly enlarged ("hypertrophied"). While examining Linyphiidae Blackwall, 1859 specimens from Yunxia Cave in China's Jilin Province, we discovered a new cave-dwelling species of the genus Flagelliphantes, F.yunxia sp. n. In this paper, we provide detailed description and photos of its diagnostic somatic and genitalic features. It is the first record of the genus from China.

Christovizetes Krivolutsky (Acari: Oribatida: Microzetidae), a newly recorded genus from caves in China, with description of a new species

A new species of oribatid mites of the genus Christovizetes (Acari: Oribatida: Microzetidae), Christovizetes longisaetosus sp. nov. is described based on adult specimens collected from caves in Yunnan Province, Southwestern China. This genus is reported from China for the first time. The new species could be distinguished from other three known species of the genus by the following combination of characteristics: (1) distinctly longer notogastral setae lm, lp, h<sub>1-3</sub>, (2) notogastral setae lp located anterior to lyrifissure im, (3) each lamellar cusp with four teeth, among which two inner teeth much longer and thinner than two outers, (4) aggenital setae smooth. A key to the four species of this genus is given.

Precipitation variations of western equatorial pacific during glacial–interglacial cycles since MIS8: Evidence from multi–proxies of abyssal sediment

As an important global water vapor source, the Western Pacific warm pool (WPWP) influences precipitation changes in middle and low latitudes. The low-latitude water cycle is a key climate parameter at different time scales, as it contributes to various feedback processes. However, at present, indicators of precipitation variability in the equatorial western Pacific are limited. In this work, we used the sedimentary record of the southern margin of the WPWP to study the precipitation variability over the western equatorial Pacific since MIS8. The age framework based on plankton-foraminifera δ18O was used to analyze changes in geochemical elements, clay minerals, and magnetic parameters of a marine sediment core H10. As new precipitation records, our precipitation records (TiO2, χ, and SIRM concentration without carbonate base) are closely related to monsoon and Intertropical Convergence Zone and generally in inverse phase with the oxygen isotope records of stalagmites from caves in China. A spectral analysis showed an obvious precession period. The southern margin of the WPWP water cycle is closely related to the East Asian monsoon in the last four climate cycles, and is influenced by both high and low latitudes.

Gut bacteria reflect the adaptation of Diestrammena japanica (Orthoptera: Rhaphidophoridae) to the cave.

The gut microbiota is essential for the nutrition, growth, and adaptation of the host. Diestrammena japanica, a scavenger that provides energy to the cave ecosystem, is a keystone species in the karst cave in China. It inhabits every region of the cave, regardless of the amount of light. However, its morphology is dependent on the intensity of light. Whether the gut bacteria reflect its adaptation to the cave environment remains unknown. In this research, D. japanica was collected from the light region, weak light region, and dark region of three karst caves. The gut bacterial features of these individuals, including composition, diversity, potential metabolism function, and the co-occurrence network of their gut microbiota, were investigated based on 16S rRNA gene deep sequencing assay. The residues of amino acids in the ingluvies were also evaluated. In addition, we explored the contribution of gut bacteria to the cave adaptation of D. japanica from three various light zones. Findings showed that gut bacteria were made up of 245 operational taxonomic units (OTUs) from nine phyla, with Firmicutes being the most common phylum. Although the composition and diversity of the gut bacterial community of D. japanica were not significantly different among the three light regions, bacterial groups may serve different functions for D. japanica in differing light strengths. D. japanica has a lower rate of metabolism in cave habitats than in light regions. We infer that the majority of gut bacteria are likely engaged in nutrition and supplied D. japanica with essential amino acids. In addition, gut bacteria may play a role in adapting D. japanica's body size. Unveiling the features of the gut bacterial community of D. japanica would shed light on exploring the roles of gut bacteria in adapting hosts to karst cave environments.

A Numerical Study of the Effect of Vegetative Windbreak on Wind Erosion over Complex Terrain

Wind erosion is a typical issue for stone carvings in northwest China caves, and windbreaks such as shelterbelts have proven to be effective in mitigating wind erosion. This study has the main purpose of examining the effect of shelterbelts on alleviating the wind erosion degree of stone carvings. The applicability of the canopy model for reproducing the aerodynamic effects based on the realizable k–ε and LES model was examined by using a validation metric. The shelterbelt structure has been discussed with the goal of finding the optimum canopy structure to provide a guideline for designing shelterbelts. Compared with the LES model, the realizable k–ε model was adopted in this study based on its comprehensive performance. The results show that a canopy with porosity of φ = 30% and a width of 0.3 to 0.5 H has better sheltering efficiency. Compared to the case with no shelterbelt, the wind speed amplification coefficient decreased by 43%, and the significant decrease in the value of the wind speed amplification coefficient in the primary-harm wind direction demonstrates the effectiveness of the shelterbelt. By exploring preventive protection technology in the context of historical stone carving, this study can promote the practice of scientific and technological protection of cultural relics.

Cataloguing vascular plant diversity of karst caves in China

Cataloguing vascular plant diversity of karst caves in China

Description of four new species of the subgenus Tachycines (Gymnaeta) Adelung, 1902 (Orthoptera: Rhaphidophoridae) from caves in China and additional notes on some previously known species

In this paper, four new cave-dwelling species of the subgenus Tachycines (Gymnaeta) from Guangxi, Hunan and Jiangxi are described, i.e., Tachycines (Gymnaeta) quadratus sp. nov., Tachycines (Gymnaeta) shiziensis sp. nov., Tachycines (Gymnaeta) sparsispinus sp. nov. and Tachycines (Gymnaeta) papilious sp. nov. The female of Tachycines (Gymnaeta) liboensis Zhu, Chen & Shi, 2020 is recorded for the first time. Moreover, images illustrating the morphology of the four new and three previously described species are provided.

New and interesting palpigrades (Arachnida, Palpigradi) of the genera Koeneniodes Silvestri, 1913 and Prokoenenia Börner, 1901 from Asia.

Two new species of palpigrades are described: a soil-dwelling species of the genus Koeneniodes Silvestri, 1913 from a broadleaf forest in Tibet and an extraordinary cave-dwelling species from Jinhua cave in China belonging to Prokoenenia Börner, 1901. Koeneniodes tibetanus sp. n. is related to Koeneniodes spiniger from Thailand. The two species share the presence of four thick and spiniform setae on the second lobe of the female genitalia; they differ in the number of thick setae on opisthosomal sternite IV, the number of cheliceral teeth, the coxal setal formula, and the morphology of the spiniform setae. Prokoenenia sarcodactylica sp. n. is based on an immature female from Jinhua Cave, Beijing. The presence of 18 finger-shaped blades in the lateral organs-unique among palpigrades , the large body size (2150 μm) and the extremely long basitarsus IV (205 μm) indicate that the new species is the first undoubtedly caveadapted Prokoenenia. This is also the first record of the genus Prokoenenia from China.

Asian cave-adapted diplurans, with the description of two new genera and four new species (Arthropoda, Hexapoda, Entognatha)

Twenty-nine specimens of Diplura collected from eight caves in China and Myanmar contain two new genera, Hubeicampa Sendra & Lips gen. nov. and Mueggejapyx Sendra & Komerički gen. nov., as well as four new species, Anisuracampa ywangana Sendra & Komerički sp. nov., Hubeicampa melissa Sendra & Lips gen. et sp. nov., Pacificampa wudonghuii Sendra sp. nov. and Mueggejapyx brehieri Sendra & Komerički gen. et sp. nov. These cave-adapted taxa showcase an impressive diversity in morphological adaptation (troglomorphy) to cave ecosystems. Their sensorial equipment, setae and receptors in the cupuliform organ have unique forms (H. melissa gen. et sp. nov.), as well as the pretarsus sticky surface (A. ywangana sp. nov. and H. melissa gen. et sp. nov.). Recent contributions on Asian diplurans, together with the taxonomic novelties shown in the present study, highlight the biogeographical importance of the Asian biodiversity. Asia is revealed as a continent with vast karst regions still waiting to be explored and new dipluran species waiting to be discovered.

Evidence for Solar Modulation on the Millennial-Scale Climate Change of Earth

In this study, we use available reconstructed data to investigate periodicities of solar activity (i.e., sunspot number) and the Earth’s climate change (temperatures of Lake Qinghai in China and Vostok in Antarctica, the GISP δ18O climate record of Greenland, and the stalagmite δ18O monsoon records of Dongge Cave in China) as well as their cross-wavelet coherences on millennial scale. We find that the variations of the Earth’s climate indices exhibited the 1000-year cyclicity, which was recently discovered in solar activity (called Eddy cycle). The cross-wavelet correlations between the millennium-cycle components of sunspot number and the Earth’s climate change remains both strong and stable during the past 8640 years (BC 6755–AD 1885). The millennial variation of sunspot number keeps in-phase with variations of Lake Qinghai temperature, Greenland temperature, and East Asian Monsoon, but anti-phase with the variation of Antarctica temperature. The strong and stable resonant relationships between sunspot numbers and these climate indices indicate that solar variability may have played a role in modulation on this millennial seesaw pattern of the Earth’s climate change before the modern industrial era.

Culturable mycobiota from Karst caves in China II, with descriptions of 33 new species

Karst caves are characterized by darkness, low temperature, high humidity, and oligotrophic organisms due to its relatively closed and strongly zonal environments. Up to now, 1626 species in 644 genera of fungi have been reported from caves and mines worldwide. In this study, we investigated the culturable mycobiota in karst caves in southwest China. In total, 251 samples from thirteen caves were collected and 2344 fungal strains were isolated using dilution plate method. Preliminary ITS analyses showed that these strains belonged to 610 species in 253 genera. Among these species, 88.0% belonged to Ascomycota, 8.0% Basidiomycota, 1.9% Mortierellomycota, 1.9% Mucoromycota, and 0.2% Glomeromycota. The majority of these species have been previously known from other environments, and some of them are known as mycorrhizal or pathogenic fungi. About 52.8% of these species were discovered for the first time in karst caves. Based on morphological and phylogenetic distinctions, 33 new species were identified and described in this paper. Meanwhile, one new genus of Cordycipitaceae, Gamszarea, and five new combinations are established. This work further demonstrated that Karst caves encompass a high fungal diversity, including a number of previously unknown species. Taxonomic novelties: New genus: Gamszarea Z.F. Zhang & L. Cai; Novel species: Amphichorda cavernicola, Aspergillus limoniformis, Aspergillus phialiformis, Aspergillus phialosimplex, Auxarthron chinense, Auxarthron guangxiense, Auxarthronopsis globiasca, Auxarthronopsis pedicellaris, Auxarthronopsis pulverea, Auxarthronopsis stercicola, Chrysosporium pallidum, Gamszarea humicola, Gamszarea lunata, Gamszarea microspora, Gymnoascus flavus, Jattaea reniformis, Lecanicillium magnisporum, Microascus collaris, Microascus levis, Microascus sparsimycelialis, Microascus superficialis, Microascus trigonus, Nigrospora globosa, Paracremonium apiculatum, Paracremonium ellipsoideum, Paraphaeosphaeria hydei, Pseudoscopulariopsis asperispora, Setophaeosphaeria microspora, Simplicillium album, Simplicillium humicola, Wardomycopsis dolichi, Wardomycopsis ellipsoconidiophora, Wardomycopsis fusca; New combinations: Gamszarea indonesiaca (Kurihara & Sukarno) Z.F. Zhang & L. Cai, Gamszarea kalimantanensis (Kurihara & Sukarno) Z.F. Zhang & L. Cai, Gamszarea restricta (Hubka, Kubatova, Nonaka, Cmokova & Řehulka) Z.F. Zhang & L. Cai, Gamszarea testudinea (Hubka, Kubatova, Nonaka, Cmokova & Řehulka) Z.F. Zhang & L. Cai, Gamszarea wallacei (H.C. Evans) Z.F. Zhang & L. Cai.

Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate

δ18O and δD values in meteoric groundwaters reflect those in their source precipitation, which normally displays seasonal ranges of several to many permil. Normally there are substantial reductions in the groundwater isotopic ranges due to mixing in any vegetation, soil cover and the aquifer itself, plus the distortions that can be introduced by evaporation. Nevertheless, in carbonate karst regions (and others) many spring waters are found to preserve significant proportions of these seasonal signals. They are of current interest because they may also be detected in calcite speleothems precipitated from groundwater in caves, in calcretes and calcareous nodules in soils, etc. thus permitting detailed paleoclimate reconstructions.This paper presents some baseline data on reduction of isotope seasonal signals in groundwater that are pertinent to such speleothem studies. They are from artificial tank experiments at Shawan Karst Test Site, Guizhou, China. The climate is humid subtropical with mean annual precipitation of 1340 mm, >80% falling between May and October. The concrete tanks measure 20 × 5 m, 3 m deep each, point-drained at one end to simulate a spring. They are filled with 2.5 m of local limestone quarry gravel, creating carbonate aquifers with primary porosities ∼ 50%. A first tank is left bare, simulating the rocky desertification found in parts of the region. The other tanks are topped with 0.5 m of local, clay-rich residual soil, one left bare, the other three sown with rainy season corn, permanent grass and permanent shrubs respectively. Measurements cover the three climatic years, November 2015-November 2018. > 90% of the rainfall events were sampled, and the drains every ten days.δ18O and δD in the rainfall displayed strong and regular sinusoidal oscillations with the successive seasons. In the bare rock tank these were reduced (damped) by 56~74% in the different years, with phase (time) lags of 127~134 days at the drain. In the soil-topped tanks damping ranged from 61% to 93% and the time lags from 164 to 202 days: differences between them are not statistically significant but all do differ significantly from the bare rock. In all cases, the responses of the two isotopes were similar in direction and magnitude. The 0.5 m soil cover had the most important effect. The bare rock aquifer conserved the most information. Losses were similar in the four soil-topped tanks, responding to stronger evaporation and obstruction of flow in the soil. These findings are briefly compared to seasonal isotope variations reported in speleothem drip waters in limestone caves in China and elsewhere in the world.

The long-term monitoring and evaluation of cement-based grout used to govern the water seepage of karst caves in China

Water seepage is the primary cause of stone carvings corrosion in karst caverns, which is typically treated with cement-based grout intervention. In this paper, long-term monitoring (more than 1 1/2 years) was carried out in Qinglin cave and Yanxia cave in Hangzhou, China, to quantitatively evaluate the advantages and disadvantages of ordinary Portland cement- and superfine cement-based grout intervention. Results showed that both materials were efficient in preventing water seepage, reducing it by half after the grout interventions. Grout intervention had obvious efficacy in blocking off the strong water seepage points, at the same time decreasing seepage differences among seepage points. Ion Chromatography results suggested that the concentrations of Ca2+, Cl− and SO42− in the seeped water in both caves increased after intervention, and the concentration of SO42− in the seeped water after superfine cement application in Qinglin cave was much more than that in the seeped water in Yanxia cave, where ordinary Portland cement was applied. Therefore, using superfine cement may bring more potential risks than ordinary Portland cement. However, X-ray diffraction (XRD) and conductivity analysis results presented that these ions seemly did not deposit on rock surfaces of the caves during the monitoring period.

The variability of frontal and occipital features of Homo erectus: a comparative analysis of unpublished fragmentary fossils from Sangiran, Indonesia

Since the first publication of Dubois in 1894, the diagnosis of Homo erectus is based on a list of morphological features established and updated after successive major discoveries made in the 20th century. While the existence and limits of the Homo erectus s.l is still debated, the homogeneity of the Indonesian Homo erectus, which covers a chronological period of ca. 1.5 million years, is also regularly questioned. Most of the studies addressing this question remain focused on the few most preserved specimens, even if a significant number of fragmentary specimens are available which could help to better appreciate the morphological variability of this species. In this present analysis, several unpublished fragmentary frontal (n=6) and occipital (n=9) bones recovered from the Pucangan and Kabuh layers in the Sangiran dome (Central Java) are described, analyzed and compared to the 3D models of contemporaneous (Trinil, Sangiran) and younger (Solo series) Indonesian H. erectus, specimens from Zhoukoudian Lower Cave in China, Dmanisi (Georgia), as well as East African hominins (East and West Turkana, Olduvai). The results help to precise the anatomical characteristics of these isolated human remains and increase our knowledge of Javanese Homo erectus morphological variability.

Late Quaternary climate in southern China deduced from Sr–Nd isotopes of Huguangyan Maar sediments

The hydro-climatic conditions that prevailed during the last Glacial and early to mid-Holocene periods in South China are inferred from chemical compositions and Sr–Nd isotope ratios of sediments from lake Huguangyan Maar and its vicinity. The lake sediments are comprised of organic matter, volcanic materials and aeolian input from nearby granitoid-derived soils. Variations in 87Sr/86Sr ratios in the lake sediments indicate two modes of climate conditions: wet intervals during which the lake sediments are mainly derived from the volcanic-lake rim materials, expressed in low 87Sr/86Sr ratios, and dry intervals during which fine particles from the nearby granitic soils are windblown to the lake and supply local dust expressed in high 87Sr/86Sr ratios in the sediments. These wet and dry intervals generally correspond to regional climate records (e.g., speleothem δ18O profiles in southeast China) and correlate with global climate events (e.g., Heinrich events). While δ18O records of speleothems from southeast China caves are dominated by the precession signal, the Huguangyan Maar Sr record mainly correlates with obliquity. This most likely reflects masking of the precession signal due to regional climate variability, accentuating the obliquity signal. These local effects may also account for some of the differences that have been observed between the various East Asian monsoon records. More importantly, the masking of the precession signal reveals the direct influence of obliquity on the hydro-climate regime in South China.

Eight new Arthrinium species from China.

The genus Arthrinium includes important plant pathogens, endophytes and saprobes with a wide host range and geographic distribution. In this paper, 74 Arthrinium strains isolated from various substrates such as bamboo leaves, tea plants, soil and air from karst caves in China were examined using a multi-locus phylogeny based on a combined dataset of ITS rDNA, TEF1 and TUB2, in conjunction with morphological characters, host association and ecological distribution. Eight new species were described based on their distinct phylogenetic relationships and morphological characters. Our results indicated a high species diversity of Arthrinium with wide host ranges, amongst which, Poaceae and Cyperaceae were the major host plant families of Arthrinium species.

Abrupt monsoonal shifts over the precessional cycles documented in Yongxing Cave in China during the antepenultimate glacial period

Precession is the major orbital control of monsoon intensity, but the monsoonal response to the transition between precessional cycles has yet to be explored. Here, we present an Asian Summer Monsoon history that spans 327.7–280.5 ka BP based on a 230Th-dated and centennially resolved multi-proxy speleothem record from Yongxing Cave, central China. The δ18O profile, a proxy of monsoon intensity, follows the summer insolation changes, with three abrupt shifts occurring at precessional transitions. These shifts are supported by the stalagmite δ13C, grey-level and petrography analysis, indicating a coherent link between the karst processes and monsoon changes. Evidence from the coeval rapid changes in atmospheric CH4 and forest evolution records within dating errors suggests a wider regional signal of monsoon changes. The weak monsoon intervals are temporally consistent with the ice-rafted debris layers in the North Atlantic, indicating a strong coupling of the high- and low-latitude climate systems. We speculate that the abrupt monsoonal shifts are initiated by the south–north shifts of the Intertropical Convergence Zone associated with the Atlantic Meridional Overturning Circulation and further amplified by land cover. In addition, the rates and magnitudes of insolation changes modify monsoon shifts, thus indicating the abrupt monsoonal shift as a result of an interaction of orbital and millennial forcing.