Influence of photosynthetic active radiation on sap flow dynamics across forest succession stages in Dinghushan subtropical forest ecosystem.

With the intensification of global change, forests are subjected to varying degrees of drought or high-temperature stress, which has an indelible impact on the growth of trees. However, knowledge on the response of sap flow to environmental changes in different types of forests is still rare, especially in China's subtropical forest ecosystem. Consequently, studying how different tree species regulate their sap flow in response to shifting environmental conditions is essential for understanding forest transpiration, water use efficiency, and drought stress resilience.

Anti-inflammatory and cytotoxicity nitrogenous merosesquiterpenoids from the sponge Pseudoceratina purpurea.

Fourteen undescribed nitrogenous merosesquiterpenoids, purpurols A-D (1-4) and puraminones A-J (5-14), along with three known related compounds (15-17) were isolated from the sponge Pseudoceratina purpurea collected in the South China Sea. Their structures and absolute configurations were unambiguously elucidated by a combination of spectroscopic data, X-ray diffraction analysis, electronic circular dichroism calculations, and chemical derivatization. Purpurols A-D (1-4) incorporated nitrogenous heterocycles, compounds 1 and 2 feature an unusual benzothiazole ring, while 3 and 4 feature benzoxazole ring.

Sarcocinerenolides A, an open-loop decarbonizing cembranolide, and sarcocinerenolides B-I, eight polyoxygenated cembranolides with anti-thrombotic activity from the South China Sea soft coral Sarcophyton cinereum.

A previously undescribed open-loop decarbonizing cembranolide, sarcocinerenolide A, and eight undescribed cembranolides, sarcocinerenolides B-I, characterized by poly-membered oxygen ring fragments were isolated from the soft coral Sarcophyton cinereum collected from the South China Sea. The structures and absolute configurations of these previously undescribed compounds were precisely determined by analysis of NMR data, DP4+ and ECD spectra. The bioactivities of the compounds were evaluated using zebrafish models and sarcocinerenolides C and H exhibited anti-thrombotic activity.

Terpenoids from the Soft Coral .

A detailed chemical study of the extract from the soft coral resulted in the isolation and identification of seven new sesquiterpenoids, bellissinanes A-G (-), along with four new diterpenes (-). Bellissinane A () is the third reported nardosinane-type sesquiterpene bearing a 6/5/6 tricyclic system. Bellissinanes C and D (, ) contain a phenylethylamine fragment, which is relatively unusual in marine organisms.

Long-term warming increased carbon sequestration capacity in a humid subtropical forest.

Tropical and subtropical forests play a crucial role in global carbon (C) pools, and their responses to warming can significantly impact C-climate feedback and predictions of future global warming. Despite earth system models projecting reductions in land C storage with warming, the magnitude of this response varies greatly between models, particularly in tropical and subtropical regions. Here, we conducted a field ecosystem-level warming experiment in a subtropical forest in southern China, by translocating mesocosms (ecosystem composed of soils and plants) across 600 m elevation gradients with temperature gradients of 2.

Climate change-related biodiversity fluctuations and composition changes in an old-growth subtropical forest: A 26-yr study.

The detection and attribution of biodiversity change is of great scientific interest and central to policy effects aimed at meeting biodiversity targets. Yet, how such a diverse climate scenarios influence forest biodiversity and composition dynamics remains unclear, particularly in high diversity systems of subtropical forests. Here we used data collected from the permanent sample plot spanning 26 years in an old-growth subtropical forest.

Soil microbial community structure, function and network along a mangrove forest restoration chronosequence.

Mangrove forests have high ecological, social and economic values, but due to environmental changes and human activities, natural mangrove forests have experienced serious degradations and reductions in distribution area worldwide. In the coastal zones of southern China, an introduced mangrove species, Sonneratia apetala, has been extensively used for mangrove restoration because of its rapid growth and strong environmental adaptability. However, little is known about how soil microorganisms vary with the restoration stages of the afforested mangrove forests.

Climate change reshapes plant trait spectrum to explain biomass dynamics in an old-growth subtropical forest.

Climate change leads to novel species interactions and continues to reshuffle ecological communities, which significantly declines carbon accumulation rates in mature forests. Still, little is known about the potential influence of multiple global change factors on long-term biomass dynamics and functional trait combinations. We used temporal demographic records spanning 26 years and extensive databases of functional traits to assess how old-growth subtropical forest biomass dynamics respond to various climatic change scenarios (extreme drought, subsequent drought, warming, elevated CO concentrations, and windstorm).

Pseudoceranoids A-J, Sesquiterpene-Based Meroterpenoids with Cytotoxicity from the Sponge .

Pseudoceranoid A (), a rare merosesquiterpene featuring a rearranged 4,9-friedodrimane-type core with a crotonolactone moiety, two new rearranged 4,9-friedodrimane-type sesquiterpene cyclopentanones ( and ), and three new rearranged 4,9-friedodrimane-type sesquiterpene hydroquinones (-), along with two new drimane-type sesquiterpene derivatives ( and ), as well as two new 4,9-friedodrimane-type sesquiterpene quinones ( and ), were isolated from the South China Sea sponge . The structures of compounds were established by analysis of spectroscopic data, as well as by single-crystal X-ray diffraction, DP4+ probability analyses, and calculated electronic circular dichroism. Compound showed weak cytotoxicity against K562, H69AR, and MDAMB-231 cell lines with IC values of 3.

Cytotoxic Epipolythiodioxopiperazines from the Deep-Sea-Derived Fungus MCCC 3A00939.

Four new aranotin-type epipolythiodioxopiperazines, graphiumins K-N (-), along with four known analogues (-), were isolated from the deep-sea-derived fungus MCCC 3A00939. Their structures were elucidated by detailed interpretation of NMR and mass spectrometric data. The absolute configuration of the isolates was deduced by a single-crystal X-ray diffraction analysis and the comparisons of experimental electronic circular dichroism (ECD) data with calculated ECD spectra.

Carbon sequestration and storage capacity of Chinese fir at different stand ages.

In southern China, Chinese fir Cunninghamia lanceolata is one of the most important native conifer trees, widely used in afforestation programs. This area has the largest forestland atmospheric carbon sink, and a relatively young stand age characterizes these forests. However, how C.

Heterolactone and Heterolactams A-M, Verticillane Diterpenoids with Anti-Inflammatory and Hepatoprotective Activities from the Soft Coral .

Fourteen new verticillane diterpenoids, heterolactone () and heterolactams A-M (-), were isolated from the soft coral . They structurally share the same 6/12 bicyclic carbon skeleton that is not commonly encountered in marine organisms. The structures, including the absolute configurations, were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction analysis, calculated ECD spectra, and DP4+ probability analyses.

Tracking biomedical articles along the translational continuum: a measure based on biomedical knowledge representation.

Keeping track of translational research is essential to evaluating the performance of programs on translational medicine. Despite several indicators in previous studies, a consensus measure is still needed to represent the translational features of biomedical research at the article level. In this study, we first trained semantic representations of biomedical entities and documents (i.

Sarcoeleganolides C-G, Five New Cembranes from the South China Sea Soft Coral .

Five new cembranes, named sarcoeleganolides C-G (-), along with three known analogs (-) were isolated from soft coral collected from the Yagong Island, South China Sea. Their structures and absolute configurations were determined by extensive spectroscopic analysis, QM-NMR, and TDDFT-ECD calculations. In addition, compound exhibited better anti-inflammation activity compared to the indomethacin as a positive control in zebrafish at 20 μM.

Subergorgines A-E, five new suberosanone-purine hybrids from the South China Sea gorgonian Subergorgia suberosa.

Five new suberosanone-purine hybrids, namely subergorgines A-E (1-5), were isolated from the South China Sea gorgonian Subergorgia suberosa. Their structures were elucidated on the basis of extensive spectroscopic data and the absolute configurations were clarified by the theoretical ECD calculation. Compounds 1-5 were rare purine alkaloids merged with the same suberosanone moiety via different C (6)-N bridges.

Tree species richness as an important biotic factor regulates the soil phosphorus density in China's mature natural forests.

Tree species richness has been recognized as an underlying driving factor for regulating soil phosphorus (P) status in many site-specific studies. However, it remains poorly understood whether this is true at broad scales where soil P strongly rely on climate, soil type and vegetation type. Here, based on the data of 946 mature natural forest sites from a nationwide field survey in China, we analyzed the impact of tree species richness on soil P density of China's mature natural forests (deciduous coniferous forest, DCF; evergreen coniferous forest, ECF; deciduous broad-leaved forest, DBF; evergreen broad-leaved forest, EBF; and mixed coniferous and broad-leaved forest, MF).

Four bioactive new steroids from the soft coral collected in South China Sea.

Four new polyhydroxylated steroids lobophysterols E-H (-), together with three known compounds (-), were isolated from the soft coral collected at Xisha Island, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and comparison with NMR data of structurally related compounds reported in the literature. The absolute configuration of - was determined by X-ray diffraction.

Guaiane sesquiterpenes from the gorgonian collected in the South China Sea.

Echinoflorine (1), a new dimethylamino-substituted guaipyridine alkaloid with a novel γ-lactone-cyclohepta[]pyridine fused skeleton, and three new guaiane sesquiterpene lactones, echinofloranolides A-C (2-4), together with eight known guaiane sesquiterpenes were isolated from the gorgonian collected in the South China Sea. Their structures were elucidated by 1D and 2D NMR, HRESIMS, calculated ECD and DP4+ probability analyses.

Internationalizing AI: evolution and impact of distance factors.

Unlabelled: International collaboration has become imperative in the field of AI. However, few studies exist concerning how distance factors have affected the international collaboration in AI research. In this study, we investigate this problem by using 1,294,644 AI related collaborative papers harvested from the Microsoft Academic Graph dataset.

Dolabellane Diterpenes and Elemane Alkaloids from the Soft Coral Collected in the South China Sea.

Five new dolabellane diterpenes, clavularinlides A-E (-), and four new racemic elemane alkaloids, clavulacylides A-D (-), together with one known compound (), were isolated from the soft coral collected in the South China Sea. Their structures were elucidated by 1D and 2D NMR, HRESIMS, calculated ECD, and DP4+ probability analyses. Compounds - showed anti-inflammatory activity in the zebrafish assay.

Lemnalemnanes A-C, Three Rare Rearranged Sesquiterpenoids from the Soft Corals and sp.

Three novel sesquiterpenoids, lemnalemnanes A-C (-), were obtained from marine soft corals and sp. Their structures were determined by 1D/2D NMR spectroscopy, HRESIMS, single-crystal X-ray diffraction analysis (Cu Kα), Mosher's method, and ECD quantum chemistry calculations. Lemnalemnane A () possessed an intriguing basket-like structure with a spiro[bicyclo[3.

Tropical tall forests are more sensitive and vulnerable to drought than short forests.

Our limited understanding of the impacts of drought on tropical forests significantly impedes our ability in accurately predicting the impacts of climate change on this biome. Here, we investigated the impact of drought on the dynamics of forest canopies with different heights using time-series records of remotely sensed Ku-band vegetation optical depth (Ku-VOD), a proxy of top-canopy foliar mass and water content, and separated the signal of Ku-VOD changes into drought-induced reductions and subsequent non-drought gains. Both drought-induced reductions and non-drought increases in Ku-VOD varied significantly with canopy height.

Jellynolide A, pokepola esters, and sponalisolides from the aquaculture sponge Spongia officinalis L.

Jellynolide A, an unreported bicyclic diterpenoid with an unprecedented penta-substituted carbon skeleton which implied an irregular biogenic pathway, together with four pairs of rare phosphate triesters, (±)-pokepola ester B-E, one undescribed related racemic furanoterpenoid, (±)-sponalisolide C, one undescribed furanoterpenoid, (-)-sponalisolide D, and two known (±)-sponalisolide B and dendrolasin carboxylic acid were isolated from the aquaculture Spongia officinalis L. Their structures were elucidated by comprehensive spectroscopic analysis, quantum chemical calculation of NMR parameters, and electronic circular dichroism (ECD). The plausible biosynthetic pathway of jellynolide A was proposed.

Natural forests promote phosphorus retention in soil.

Soil phosphorus (P) availability often limits plant productivity. Classical theories suggest that total P content declines at the temporal scale of pedogenesis, and ecosystems develop toward the efficient use of scarce P during succession. However, the trajectory of ecosystem P within shorter time scales of succession remains unclear.