Old Pinus massoniana forests benefit more from recent rapid warming in humid subtropical areas of central-southern China

Trees progress through various growth stages,each marked by specific responses and adaptation strate-gies to environmental conditions.Despite the importance of age-related growth responses on overall forest health and management policies,limited knowledge exists regarding age-related effects on dendroclimatic relationships in key subtropical tree species.In this study,we employed a den-drochronological method to examine the impact of rapid warming on growth dynamics and climatic sensitivity of young(40–60 years)and old(100–180 years)Pinus mas-soniana forests across six sites in central-southern China.The normalized log basal area increment of trees in both age groups increased significantly following rapid warming in 1984.Trees in young forests further showed a distinct growth decline during a prolonged severe drought(2004–2013),whereas those in old forests maintained growth increases.Tree growth was more strongly influenced by temperature than by moisture,particularly in old forests.Spring tem-peratures strongly and positively impacted the growth of old trees but had a weaker effect on young ones.Old forests had a significantly lower resistance to extreme drought but faster recovery compared to young forests.The“divergence problem”was more pronounced in younger forests due to their heightened sensitivity to warming-induced drought and heat stress.With ongoing warming,young forests also may initially experience a growth decline due to their heightened sensitivity to winter drought.Our findings underscore the importance of considering age-dependent changes in forest/tree growth response to warming in subtropical forest man-agement,particularly in the context of achieving“Carbon Peak&Carbon Neutrality”goals in China.

Long-term changes in radial growth of seven tree species in the mixed broadleaf-Korean pine forest in Northeast China:Are deciduous trees favored by climate change?

The role of the temperate mixed broadleaf-Korean pine forest(BKF)in global biogeochemical cycles will depend on how the tree species community responds to climate;however,species-specific responses and vulner-abilities of common trees in BKF to extreme climates are poorly understood.Here we used dendrochronological meth-ods to assess radial growth of seven main tree species(Pinus koraiensis,Picea jezoensis,Abies nephrolepis,Fraxinus mandshurica,Phellodendron amurense,Quercus mongolica,and Ulmus davidiana)in an old-growth BKF in response to climate changes in the Xiaoxing’an Mountains and to improve predictions of changes in the tree species compo-sition.Temperature in most months and winter precipita-tion significantly negatively affected growth of P.jezoensis and A.nephrolepis,but positively impacted growth of P.koraiensis and the broadleaf species,especially F.mandshu-rica and U.davidiana.Precipitation and relative humidity in June significantly positively impacted the growth of most tree species.The positive effect of the temperature during the previous non-growing season(PNG)on growth of F.mandshurica and Q.mongolica strengthened significantly with rapid warming around 1981,while the impact of PNG temperature on the growth of P.jezoensis and A.nephrolepis changed from significantly negative to weakly negative or positive at this time.The negative response of radial growth of P.jezoensis and A.nephrolepis to precipitation during the growing season gradually weakened,and the negative response to PNG precipitation was enhanced.Among the studied species,P.koraiensis was the most resistant to drought,and U.davidiana recovered the best after extreme drought.Ulmus davidiana,P.jezoensis and A.nephrolepis were more resistant to extreme cold than the other species.Climate warming generally exacerbated the opposite growth patterns of conifer(decline)and broadleaf(increase)spe-cies.Deciduous broadleaf tree species in the old-growth BKF probably will gradually become dominant as warming continues.Species-specific growth-climate relationships should be considered in future models of biogeochemical cycles and in forestry management practices.

Spatial and temporal patterns of the sensitivity of radial growth response by Picea schrenkiana to regional climate change in the Tianshan Mountains

Climate change significantly impacts forest ecosystems in arid and semi-arid regions.However,spatiotemporal patterns of climate-sensitive changes in individual tree growth under increased climate warming and precipitation in north-west China is unclear.The dendrochronological method was used to study climate response sensitivity of radial growth of Picea schrenkiana from 158 trees at six sites during 1990-2020.The results show that climate warming and increased precipitation significantly promoted the growth of trees.The response to temperature first increased,then decreased.However,the response to increased precipitation and the self-calibrating Palmer Drought Severity Index(scPDSI)increased significantly.In most areas of the Tianshan Mountains,the proportion of trees under increased precipitation and scPDSI positive response was relatively high.Over time,small-diameter trees were strongly affected by drought stress.It is predicted that under continuous warming and increased precipitation,trees in most areas of the Tianshan Mountains,especially those with small diameters,will be more affected by precipitation.

Divergent responses of Picea crassifolia Kom.in different forest patches to climate change in the northeastern Tibetan Plateau

Global climate changes have significantly affected tree growth and forest structures and functions in some arid and semi-arid regions,which are becoming warmer and wetter.Due to natural factors such as climate and terrain,some tree species may form different forest patches at the edges of their distribution areas.However,how forest patches of various sizes respond to climate change is unclear.In this study,we collected 203 tree cores from six different sizes of forest patches at the edge of the distribution area of Picea crassifolia Kom.in the northeast Tibetan Plateau.And we used the dendrochronology method to study the response of tree growth and resilience in different forest patches to climate change from 1961 to 2020.We simultaneously measured the contents of nonstructural carbohydrates(NSC),total nitrogen and total phosphorus of tree needles.Our results showed that the growth of trees in small-and medium-size forest patches(0.8–18.6 ha)has increased significantly.The early growing season(May–July)minimum temperature was the most important climate factor driving the growth of small-and medium-sized patch trees.The early growing season maximum temperature was the most important climate factor that inhibited the growth of trees in the largest patches(362.8 ha).The growth of individual trees in medium forest patches was better and the correlation with annual minimum temperature,maximum temperature,precipitation,actual evapotranspiration,and palmer drought severity index was stronger.The higher NSC content,stronger photosynthesis,and higher nitrogen utilization efficiency in leaves might be one of the reasons for the better growth of trees in moderate forest patches.In extreme drought years,as the forest patch area increased,the overall trend of tree growth resistance showed a unimodal pattern,with the highest at a forest patch area of 7.1 ha,while the overall trend of tree growth recovery was opposite.Therefore,we should strengthen the management of trees in large forest patches to cope with climate change.

Efficacy and safety of chemotherapy combined with bevacizumab in Chinese patients with metastatic colorectal cancer:A prospective,multicenter,observational,non-interventional phaseⅣtrial

Objective:Bevacizumab has an important and evolving role in improving outcomes in patients with metastatic colorectal cancer(mCRC)worldwide and was approved in China in 2010.However,there are limited real-world data on the efficacy and safety of chemotherapy regimens combined with bevacizumab in Chinese patients with mCRC.This observational,phase IV trial study aimed to obtain more experience on the efficacy and safety of bevacizumab combined with chemotherapy in Chinese mCRC patients.Methods:Between September 2013 and November 2016,patients with histologically confirmed mCRC were enrolled in a prospective,multicenter,observational,non-interventional phase IV trial at 26 centers across China.Eligible patients received different chemotherapeutic regimens combined with bevacizumab.The efficacy and safety data in the intention-to-treat study population were analyzed.Results:A total of 611 patients were included in the efficacy analysis.The median overall survival and median progression-free survival was 18.00 and 10.05 months,respectively.The objective response rate was 21.00%and disease control rate was 89.40%.In subgroup analyses,the survival differences were observed according to metastatic status,duration of treatment and elevation in blood pressure.A total of 613 patients were evaluable for safety assessments.And 569(92.82%)patients reported at least one adverse event(AE),and 151(24.63%)experienced grade 3 or higher AEs.The incidence of bevacizumab-associated AEs of special interest was reported in 31(5.06%)patients with hypertension(n=12),abscesses and fistulae(n=7),bleeding(n=6),proteinuria(n=3),gastrointestinal perforation(n=2)and venous thrombotic events(n=1).Conclusions:This observational phase IV trial broadens our experience and knowledge of bevacizumab in the Chinese population and provides a good indication of its overall efficacy and safety.Bevacizumab in combination with chemotherapy offers clinical benefits to Chinese patients with mCRC and has an acceptable and manageable safety profile.

From common biomass materials to high-performance tissue engineering scaffold: Biomimetic preparation, properties characterization, in vitro and in vivo evaluations

Converting common biomass materials to high-performance biomedical products could not only reduce the environmental pressure associated with the large-scale use of synthetic materials,but also increase the economic value.Chitosan as a very promising candidate has drawn considerable attention owing to its abundant sources and remarkable bioactivities.However,pure chitosan materials usually exhibit insufficient mechanical properties and excessive swelling ratio,which seriously affected their in vivo stability and integrity when applied as tissue engineering scaf-folds.Thus,simultaneously improving the mechanical strength and biological compatibility of pure chitosan(CS)scaffolds becomes very important.Here,inspired by the fiber-reinforced con-struction of natural extracellular matrix and the porous structure of cancellous bone,we built silk microfibers/chitosan composite scaffolds via ice-templating technique.This biomimetic strategy achieved 500%of mechanical improvement to pure chitosan,and meanwhile still maintaining high porosity(>87%).In addition,the increased roughness of chitosan pore walls by embedded silk microfibers significantly promoted cell adhesion and proliferation.More importantly,after subcutaneous implantation in mice for four weeks,the composite scaffold showed greater struc-tural integrity,as well as better collagenation,angiogenesis,and osteogenesis abilities,suggesting its great potential in biomedicine.

Plant size,environmental factors and functional traits jointly shape the stem radius growth rate in an evergreen coniferous species across ontogenetic stages

Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.Methods We selected 65 individuals of an evergreen coniferous species,Pinus koraiensis,with diameters at breast height(DBH)from 0.3 to 100 cm in Northeast China.For each individual,we measured the stem radius growth rate(SRGR,µm/year)for the current year,environmental factors(light,soil nutrient and soil water)and functional traits(leaf,branch and root traits).Important Findings SRGR increased with DBH when the DBH was lower than 58 cm,whereas it decreased with DBH when the DBH was larger than 58 cm.Structural equation modeling analysis suggested that,when the DBH was 0–15 cm,plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant.Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm,respectively.When the DBH was larger than 15 cm,soil parameters were more important than light intensity for SRGR.The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size.In summary,plant size,environmental factors and functional traits jointly shaped tree growth,and their relative influence varied with size,suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.

SALIRI-based(raltitrexed plus irinotecan)therapy as a second-line treatment for patients with metastatic colorectal cancer(SALLY):A prospective,multicenter,non-interventional,registry study

Primary chemotherapy options for colorectal cancer(CRC)involve four key drugs:fluorouracils(5-FU),oxaliplatin,irinotecan and raltitrexed.The first-line regimen consists of 5-FU and leucovorin combined with oxaliplatin(FOLFOX),while the second-line regimen involves 5-FU and leucovorin combined with irinotecan(FOLFIRI)for metastatic CRC(mCRC)in China[1].