The process of plant nitrogen（N） uptake from soil and its multidimensional strategies significantly influence the biodiversity and carbon sequestration functions of ecosystems. This paper systematically reviewed the development of N nutrition theories in plants， introducing mineral nutrition theory and mineral-organic nutrition theory. It focused on the multidimensional strategies that plants use to absorb soil N， covering four main aspects： （1）multiform N absorption， which includes both inorganic N（e.g. ammonium and nitrate） and a range of low molecular weight organic N forms such as amino acids， amino sugars， and oligopeptides； （2）seasonal variation in N absorption， in which plants exhibit significant seasonal variations in both the magnitude and patterns of uptake of various forms of soil N， and different species may display distinct differences in uptake patterns； （3） stratified soil layer absorption， in which the root system configuration and the variation of available soil N across soil vertical profiles influence plant absorption of N amounts and N forms at different soil depths； （4）symbiotic absorption differentiation， in which nitrogen-fixing bacteria， mycorrhizal fungi， and dark-septate endophytic fungi promote N uptake by plants and， to some extent， affect the plant’s acquisition of different N forms. It was concluded that the multidimensional strategies of plant N uptake provide a basis for plant coexistence and niche differentiation in ecosystems， playing a key role in mitigating inter-plant competition， reducing N loss， and improving N use efficiency in ecosystems. However， research on plant N uptake strategies remains insufficient， with several key scientific issues yet to be resolved， such as the in-situ availability and dynamics of soil N， the turnover differences of various available N forms in soil， the molecular biological mechanisms of plant N uptake strategies， and the contributions of different available N forms to plant N nutrition.

In terrestrial angiosperms， the balance between water supply and consumption is primarily regulated through the coordination of leaf veins and stomata， with epidermal cells playing a significant role in this process. However， research on Nymphaeaceae species remains very limited. In this study， seven species of Nymphaeaceae and six species of terrestrial herbaceous plants were selected as materials. Through quantitative analysis of floral and leaf anatomical traits， the intraspecific variation within Nymphaeaceae and the differences in floral and leaf characteristics between the two plant groups were examined. The results indicated that flowers of Nymphaeaceae plants exhibited larger stomatal size， epidermal cells size， and a higher vein density than leaves， whereas leaves displayed greater stomatal density， epidermal cell density， and stomatal index. The anatomical traits of Nymphaeaceae flowers were similar to those of terrestrial herbaceous flowers， except for epidermal cell size. However， the epidermal cell density and stomatal density of leaves were significantly higher than those of terrestrial herbs， while stomatal size， epidermal cell size， vein density and stomatal index were notably lower than those of the terrestrial herbs. The stomatal density of Nymphaeaceae flowers had no correlation with either epidermal cell size or floral vein density； in leaves， epidermal cell size had a negative correlation with stomatal density， and no significant association was found between stomatal density and leaf vein density. Principal component analysis revealed that， compared to terrestrial herbaceous plants， Nymphaeaceae flowers had an advantage in epidermal cell density； meanwhile， leaf trait spaces were completely separated， with Nymphaeaceae leaves exhibiting higher epidermal cell density and stomatal density. In conclusion， the flowers of Nymphaeaceae exhibited the traits similar with terrestrial herbs， likely due to their water-retaining characteristics， while the decoupling of stomata and veins in leaves reflected adaptive evolution in the aquatic environment. These findings provided the valuable foundation for further research on water-use characteristics and environmental adaptation mechanisms in aquatic plants.

Exploring the impact of climate warming on water use efficiency（WUE） of treesis significant for understanding the responses of tree carbon-water coupling to climate warming. In 2004， Larix gmelinii seedlings grown in four sites along temperate gradient（e.g.， Tahe， Songling， Sunwu and Dailing） simulating climate warming were transplanted to a common garden（Mao’ershan） near the natural edge of this species’ range. In August 2022， in the common garden and four different transplanting sites， the instantaneous water use efficiency（WUE_i） and intrinsic water use efficiency（WUE_g） were measured using the gas exchange method， and long-term water use efficiency（WUE_L） was calculated via carbon-13 isotope abundance to explore the effects of different simulating climate warming magnitudes on WUE of L. gmelinii. The results showed that both WUE_i and WUE_g significantly increased， with an increase of 33.37%， 38.84%， 42.06% and 58.76% for WUE_i， and an increase of 15.94%， 18.47%， 20.84% and 39.10% for WUE_g of L. gmelinii under the simulated climate warming by transplantation from the sites Tahe， Songling， Sunwu and Dailing， respectively. The WUE_L significantly increased by 16.92% and 30.56% for Songling and Tahe， respectively. The increasing rate of WUE_i， WUE_g and WUE_L showed positive linear correlations with the warming magnitude. Both WUE_i and WUE_g showed significant and similar site differences in the common garden and among the transplanting sites， while WUE_L showed significant differences only among the transplanting sites. WUE_i was sensitive to all the warming magnitudes， but WUE_L was sensitive only to the high warming magnitude. Therefore， the warming magnitude and the determining methods should be taken into consideration in tree WUE responses to climate warming.

The aim of this study was to explore the effects of variations in rainfall on the growth and C， N， P stoichiometric characteristics of Fraxinus malacophylla seedlings， which could provide a theoretical basis for the application of F. malacophylla seedlings in karst vegetation restoration. In this study， two-year-old F. malacophylla seedlings were used as materials， and the treatments with 40% increased rainfall， 40% reduced rainfall， natural rainfall， and 5- and 10-day rainfall intervals were set， and the responses of seedling biomass and C， N， P stoichiometric characteristics were investigated， respectively. The results showed that both extending the rainfall interval and reducing rainfall significantly inhibited biomass accumulation of seedlings， roots， stems， and leaves， whereas increasing rainfall had an opposite effect. Leaf C and P contents significantly increased（P<0.05）， whereas leaf N content significantly decreased under the increased rainfall（P<0.05）. Under the reduced rainfall， the contents of C， N， and P in roots， C and P in stems， C and N in leaves significantly decreased at a five-day rainfall interval（P<0.05）. The contents of C， N， and P in roots， stems， and leaves significantly decreased at a 10-day rainfall interval（P<0.05）. Under the conditions of reduced and natural rainfalls， the leaf N∶P ratio was greater than 16， indicating that the growth of seedlings was limited by P. Under the increased rainfall， the leaf N∶P ratio ranged from 14 to 16， indicating that the growth of seedlings was limited by both N and P. The above results revealed that F. malacophylla seedlings responded to rainfall changes by regulating the biomass accumulation and C， N， P stoichiometric characteristics in organs. The findings could provide a scientific basis for restoration of vegetation in Karst regions and for the cultivation and management of F. malacophylla.

To explore the species composition， floristic geographical components， and diversity characteristics and patterns of change in the herbaceous communities of waterfalls in Dehang Geological Park， three herbaceous communities of waterfalls were used as materials， and the importance values， floristic geographical components， species α and β diversity， nutritional traits， reproductive traits， and phylogenetic diversity were analyzed respectively， and the basic data of plant diversity in waterfall habitats was provided. The results indicated that a total of 85 species from 66 genera and 35 families of herbaceous plants were identified， and Aster ageratoides， Strobilanthes oligantha， Pilea notata and Pilea sinofasciata were the dominant species. The geographical distribution types were consistent with the floristic characteristics of the East Asia， with more tropical components in Dalongdong and a less proportion in Xiannvtan. In terms of alpha diversity， Shannon-Wiener and Simpson indices of plants in Dalongdong were higher， but the Pielou index was the lowest； beta diversity indices were consistent， with the highest value occurred between Dalongdong and Liusha Waterfall， and the lowest value occurred between Liusha and Xiannvtan Waterfall. The life habits were predominated by perennial herbs， with medium-sized， simple， papery， unlobed， and serrated leaves. There were differences in leaf arrangement and pubescence； reproductive traits were mainly characterized by bisexual flowers， terminal and axillary， dry fruits， and wind-dispersed seeds， with flowering periods concentrated from May to August and fruiting periods from August to October， and differences in inflorescence type. The herbaceous communities exhibited a clumped distribution， with environmental filtration being as a primary factor influencing community structure. The herbaceous community in the Dehang waterfalls exhibited unique diversity characteristics compared to the other communities.

In the context of climate change intensification and increasing limitation of arable land， improving drought tolerance in forest trees has emerged as a critical breeding goal. However， achieving enhanced stress resistance without compromising growth and biomass production remains a major challenge. In this study， transgenic 84K poplar （Populus alba×P. glandulosa ‘84K’） lines constitutively overexpressing PagPYL4 gene， an abscisic acid（ABA） receptor gene， were developed， and their physiological and growth responses were evaluated under drought stress. The results showed that under the influence of exogenous ABA， the overexpression of PagPYL4 gene significantly altered stomatal aperture in plants. Under short-term drought treatment， compared with the wild type， the overexpression of PagPYL4 gene reduced water loss and improved drought tolerance； however， it also inhibited stomatal conductance and photosynthetic rate， leading to a significant decrease in growth rate of plant height and ground diameter. Our findings demonstrated that while PagPYL4 overexpression effectively enhanced drought resistance， its indiscriminate activation can impose substantial growth penalties. This highlighted the importance of spatially and temporally regulated gene expression strategies to balance stress resilience and biomass productivity in future tree breeding programs.

Birch（Betula platyphylla）， as a perennial woody plant， is difficult to obtain homozygous plants and families due to its long growth cycle and complex genotype， which leads to slow progress in its breeding work. Double haploid breeding technology is a breeding method that has emerged in recent years. It only requires two generations to obtain homozygous plant families. Therefore， double haploid breeding technology can greatly shorten the process of forest breeding and obtain homozygous families， while the discovery and application of the DMP gene has opened up a new research direction in doubled haploid breeding. This article aimed to study the BpDMPs gene family in birch， and revealed its physicochemical properties， protein structure， systematic evolution， gene structure， chromosome distribution， and potential functions in the growth and development process of birch through bioinformatics analysis； to identify the birch DMP gene with haploid induction function in the gene family through expression pattern analysis， and verify the gene function through Arabidopsis complementation experiments. The bioinformatics analysis results showed that birch contained 14 gene family members， distributed on six chromosomes. Phylogenetic analysis showed that 14 genes in the BpDMPs gene family belonged to five branches. The predictive analysis of cis-acting elements in the promoter of the BpDMPs gene family showed that the promoter contained response elements related to growth and development， hormone metabolism， stress response， and so on. The qRT-PCR results showed that there were significant differences in the expression levels of BpDMPs in various tissues of birch， with BpDMP2 and BpDMP7 having higher expression levels in the stamens. Through Arabidopsis complementation experiments， it was demonstrated that the BpDMP7 gene can replenish the phenotype of Arabidopsisdmp8dmp9 mutant grain sterility. This article provided basic information for further studying the functions and regulatory mechanisms of the BpDMPs gene family， and offered a new perspective for understanding the roles these genes play in plant growth， development， and environmental adaptation processes.

Bowman-Birk trypsin inhibitor（BBTI） is a widely distributed trypsin inhibitor in plants， which plays an important role in the process of plant resistance to the stresses. In this study， 11 rice BBTIs gene family members were identified at the genome level by bioinformatics methods， among which 10 OsBBTI genes were clustered at the front of chromosome 1， and OsBBTI13 gene was located on chromosome 3. OsBBTIs protein had N-terminal signal peptide and contained 1-3 typical conserved Bowman-Birk type domains. The promoter region of OsBBTIs gene had response elements related to plant hormones jasmonic acid， abscisic acid and the abiotic stresses. Transcriptome data showed that all OsBBTIs gene can be induced by jasmonic acid， and most OsBBTI genes can be expressed in response to the abiotic stresses. qRT-PCR was used to analyze the expression level of OsBBTIs gene under NaHCO₃ and NaCl stresses， the results showed that the expression level of OsBBTIs gene increased under the saline-alkali stresses. This study laid a foundation for further study on the biological function of OsBBTIs proteins in abiotic stress.

The expansion of moso bamboo （Phyllostachys edulis） into adjacent forest stands affects plant and soil stability， but the mechanism underlying its successful expansion remains unclear. By investigating the effects of different nitrogen forms and microbes on growth of moso bamboo and Japanese cedar（Cryptomeria japonica）， the nutrient and microbial mechanisms of moso bamboo expansion under the background of global change were revealed. In this study， a pot experiment was conducted. Nitrogen addition treatments of 8 g·m-2 were set up （control， Con； ammonium nitrogen， N1， with ammonium sulfate （（NH₄）₂SO₄） solution applied； nitrate nitrogen， N2， with potassium nitrate （KNO₃） solution applied）， and the soil microbial community was regulated （control， Con； bacterial inhibition， B， with 3 g·L-1 streptomycin solution applied； fungal inhibition， F， with 1 g·L-1 iprodione solution applied）. The responses of moso bamboo and Japanese cedar seedlings to nitrogen addition and microorganisms under single and mixed plantings were explored. The results showed that compared to the control， biomass and seedling height of moso bamboo and Japanese cedar significantly increased by nitrogen addition under monoculture and mixed planting， while the root-to-shoot ratio significantly decreased. In microbial treatments， both bacterial and fungal inhibition significantly reduced the biomass and height of both species（P<0.01）， indicating growth limitations. Compared to the control， bacterial inhibition reduced biomass by 13.93% and 11.57%， and height by 9.41% and 4.56% for moso bamboo and Japanese cedar， respectively. Fungal inhibition resulted in reductions of 15.84% and 10.46% in biomass and 6.90% and 3.20% in height for moso bamboo and Japanese cedar， respectively. Compared to monoculture， mixed planting significantly increased the biomass and height of moso bamboo while reducing the root-to-shoot ratio of both species by 6.01% and 5.77%（P<0.05）， respectively. Moso bamboo demonstrated stronger growth dominance under mixed planting. In nitrogen addition treatments， significant reductions in soil organic carbon and total nitrogen were observed under monoculture of Japanese cedar compared to monoculture of moso bamboo and mixed planting. Both N1 and N2 nitrogen forms significantly decreased soil pH across planting systems， with soil pH in mixed planting being higher than in monoculture. Under the context of global change， nitrogen deposition resulting from ecosystem nitrogen additions may interact with moso bamboo expansion to form a positive feedback loop， further promoting its successful expansion. With intensified nitrogen deposition， soil nutrient availability and soil microbial communities will enhance plant competitive ability by promoting nutrient absorption and resource allocation， leading to the successful expansion of moso bamboo into adjacent forest stands.

Litter is an active carbon pool in forest ecosystems， and the change of litter carbon storage directly affects the carbon sink capacity of forest ecosystems. The purpose of this study was to analyze the dynamic characteristics of litter carbon storage and stoichiometric characteristics of four forest types（natural Betula costata secondary forest， secondary broad-leaved forests， secondary coniferous-broadleaved mixed forest and original broad-leaved Korean pine forest） in different succession stages of mesophytic secondary succession of broad-leaved Korean pine forest. The aim of this study was to illustrate the effect of ecological stoichiometric characteristics of litter on its carbon storage， revealing the role of litter in ecosystem carbon sink capacity and nutrient cycling. Four forest plant communities with different succession stages in broad-leaved Korean pine forest were selected as the research objects. The standing mass， carbon storage and stoichiometric characteristics of each layer（fresh litter layer， fermentative layer， humus layer） in July and October， 2021， and May and August， 2022 were analyzed. Redundancy analysis was used to rank the effects of litter stoichiometric characteristics and upper vegetation community characteristics on litter carbon storage. Linear regression analysis was used to quantify the direct effects of litter stoichiometric characteristics on carbon storage. The main results were as follows： The total carbon storage of litter showed a trend of “decrease-increase” with the positive succession， predominantly reaching its maximum in the original broad-leaved Korean pine forest（climax community）. The litter of the climax community showed the characteristics of high C content and low P content， and the C∶N and C∶P were the highest. Redundancy analysis revealed that the conifer-to-broadleaf tree species ratio was the key factor explaining litter carbon storage variation in upper vegetation indicators， showing a positive correlation with litter carbon storage. Linear regression analysis showed that litter carbon storage was positively correlated with C∶N and C∶P， and negatively correlated with N∶P. C∶N and N∶P had the highest explanatory power for carbon storage， with R² of 0.17. This study indicated that the litter carbon storage of the climax community was higher than that of the other three communities， which was closely related to the characteristics of high C content and low P content in the litter and the high conifer-to-broadleaf tree species ratio in the climax community.

In conventional orchard planting practices， soil ammonia volatilization caused by traditional methods has shown a gradually increasing trend over the years. This study employed a portable closed chamber intermittent pumping method to investigate the effects of grass cultivation on soil ammonia volatilization in peach orchards in Shanghai. Focusing on ammonia emission levels under different vegetation cover conditions in Nanhui Peach Orchard of Pudong New District， three treatments were established： white clover cover cultivation（TM）， conventional fertilization（NM）， and a non-fertilized control（CK）. The research revealed that the annual ammonia volatilization and nitrogen loss rate under NM treatment reached 13.08 kg⋅hm^-2 and 1.15%， respectively， showing 2.91% and 4.55% higher values compared to TM treatment. The control group（CK） exhibited an annual ammonia emission of 4.40 kg⋅hm^-2. No significant difference in ammonia volatilization and nitrogen loss rates was observed between TM and NM treatments. Principal component analysis demonstrated that soil ammonia volatilization in peach orchards was positively correlated with soil ammonium nitrogen（\mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N） content and air humidity（RH）， with a particularly strong correlation to \mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N reaching statistical significance（P<0.01）. Compared with average ammonia emissions from Chinese orchards and typical orchard ammonia volatilization losses in the middle-lower Yangtze River basin， TM treatment reduced the soil ammonia emissions by 12.95% and 76.89% respectively. This experiment confirmed that white clover cover cultivation served as an effective approach to mitigate soil ammonia volatilization in peach orchards. At the same time， the cultivation has the potential of increasing fruit quality.

In order to solve the problem of unmached species to site for poplar plantations in western Songnen Plain， three poplar varieties， namely HQ（P. euramericana ‘N3016’×P. ussuriensis）， LF（P. deltoides×P. simonii ‘LongFeng-1’） and 2111Y（Populus euramericana（Dode） cv. ‘DN113’） grown in western Heilongjiang as materials， the growth parameters， stoichiometric relationship of branches and leaves， and physiological characteristics of leaves were compared and analyzed. The results showed that the averaged annual radial growth rate was in a range of 2.32-2.84 cm·a^-1， of which LF had the highest radial growth rate， followed by 2111Y， significantly higher than that of HQ. A binomial function relationship between stem diameter and stem height existed in the poplar varieties. Branch water contents of LF and 2111Y were significantly higher than that of HQ（P<0.05）. Specific leaf area of LF was higher than that of the other poplar varieties. There were significant differences in elements content and their stoichiometric ratio in the twigs and leaves of high-class twigs. Among them， the N and K contents in leaves and twigs of LF were the highest， followed by 2111Y， and HQ； P content in leaves of 2111Y was higher than that of the other poplars. Leaf C-to-N ratios of the three poplar varieties were in the range of 19.41-21.65； C-to-P ratios in the range of 6.01-9.40. There were significant differences in leaf C and N metabolism levels of the three poplar varieties. Among them， leaf content of soluble sugar， starch， and non-structure carbohydrates of HQ were higher than those of LF and 2111Y， and the contents ofNO3-andNH4+were higher than those of 2111Y， whereas leaf free amino acid content of HQ was lower than that of the other poplars. There was significant difference in plant hormone levels among the three poplar varieties， with salicylic acid contents in leaves of HQ and abscisic acid content in leaves of 2111Y significantly lower than the other poplars. The auxin content of LF leaves was lower than that of 2111Y leaves. There was no difference in leaf gibberellin content among the poplar varieties.

In order to select the excellent germplasm resources of Pinus koraiensis andprovide materials for national reserve forests construction and afforestation promotion of P. koraiensis，the offspring of superior individuals in the primary P. koraiensis seed garden of Jilin Forest Industry Dew River Technology Group Co.， Ltd. were used as materials. Analysis of variance， estimation of genetic parameters， analysis of general combining ability， correlation analysis and comprehensive evaluation were performed on tree height（H）， diameter at breast height（D_BH） and volume （V） of 218 half-sib families with 19-year-old P. koraiensis， respectively. The superior families were screened and the superior individuals were selected from the superior families. The results showed that there were extremely significant differences in H， D_BH and V among different families， blocks and families×blocks（P<0.01）. The average H of all P. koraiensis families was 3.22 m， the average D_BH was 4.79 cm， and the average V was 0.005 08 m³. The phenotypic variation coefficient of the traits ranged from 25.42% to 82.48%， the family heritability ranged from 0.86 to 0.89， and the individual heritability ranged from 0.23 to 0.38. The average values of H， D_BH and V of family PK20 were the largest， and the general combining ability values of H， D_BH and V of PK20 parent were also the largest. Besides PK20， the general combining ability values of PK33， PK6 and PK46 parents were also larger. H， D_BH and V were significantly positively correlated with each other. Therefore， 10 excellent families were screened out by multi-trait comprehensive evaluation method（5% selection rate）. The average H， D_BH and V of the selected families were 3.85 m， 6.50 cm and 0.007 50 m³， respectively. The genetic gain was 17.30%， 31.02% and 65.08%， respectively， with 11.60%， 23.81% and 62.91% higher than the local control mean value， respectively. By the same method， 10 excellent individuals were selected from excellent families（2% selection rate）. The average H， D_BH and V of the 10 selected individuals was 5.06 m， 10.72 cm and 0.023 99 m³， respectively， and the genetic gain was 11.86%， 17.31% and 38.68%， respectively， with 46.67%， 104.19% and 420.83% higher than the local control mean value， respectively. Taking growth traits as the selection target， the initially selected excellent families and individuals could be used for the application of improved varieties， providing a theoretical basis for genetic improvement of P. koraiensis and providing improved varieties for the double increase of forestry area and volume. The high-quality parents obtained by combining ability analysis could be used in hybrid breeding to produce offspring with better heredity.

In this study， 18 2-year-old Larix gmelinii families were used as materials， and the seedlings were inoculated with the highly pathogenic pine wood nematode strain FSBX by peeling casing method. By calculating the anti-symptom score， insect resistance score and disease resistance score， the larch families with resistance to pine nematode disease were comprehensively screened. Physiological indicators including contents of chlorophyll， soluble sugar， soluble protein， and activities of superoxide dismutase（SOD） and peroxidase （POD） were measured at 0^th， 5^th， 10^th and 15^th day post-inoculation， respectively. The change trend of physiological indexes of larch in the process of resistance to pine wood nematode was explored. The results indicated that larch family 1311 achieved the highest disease resistance score， followed by families 1305 and 1310. Chlorophyll content of the larch families with all resistance levels initially decreased， then increased， and then decreased again. POD activity showed a pattern of first decreasing， then increasing and then slightly declined. On the 15^th day， highly resistant families demonstrated significantly higher POD activity than that of the other families. SOD activity displayed an initial increase， followed by a decrease and peaking on the 10^th day， and highly resistant families showed significantly higher levels than that of the other families. The soluble protein content showed a trend of decreasing first and then increasing. On the 15^th day， the soluble protein content of the high-resistance family was higher than that of the other two groups， and the difference was not significant. Soluble sugar content showed a decrease-increase-decrease pattern， peaking on the 10^th day for all families， and susceptible families showed higher levels than moderate-resistance families， and that moderate-resistance families showed higher levels than high-resistance families， but there was no significant difference among the three groups. In conclusion， the high-resistance families showed significant advantages in chlorophyll content， POD and SOD activity， while the contents of soluble sugar and soluble protein were generally lower than those of the other families. However， in the later stage of inoculation， the physiological indexes of high-resistance families were higher than those of medium-resistance and susceptible families， indicating that high-resistance families could maintain high resistance in the later stage of inoculation.