Disparities in tree mortality among plant functional types(PFTs)in a temperate forest:Insights into size-dependent and PFT-specific patterns

Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This study analysed size-dependent tree mortality in a temperate forest,encompassing 46 tree species and 32,565 individuals across different PFTs(i.e.,evergreen conifer vs.deciduous broadleaf species,shade-tolerant vs.shade-intolerant species).By employing all-subset regression procedures and logistic generalized linear mixed-effects models,we identified distinct mortality patterns influenced by biotic and abiotic factors.Our results showed a stable mortality patte rn in eve rgreen conifer species,contrasted by a declining pattern in deciduous broadleaf and shadetolerant,as well as shade-intolerant species,across size classes.The contribution to tree mortality of evergreen conifer species shifted from abiotic to biotic factors with increasing size,while the mortality of deciduous broadleaf species was mainly influenced by biotic factors,such as initial diameter at breast height(DBH)and conspecific negative density.For shade-tolerant species,the mortality of small individuals was mainly determined by initial DBH and conspecific negative density dependence,whereas the mortality of large individuals was subjected to the combined effect of biotic(competition from neighbours)and abiotic factors(i.e.,convexity and pH).As for shade-intolerant species,competition from neighbours was found to be the main driver of tree mortality throughout their growth stages.Thus,these insights enhance our understanding of forest dynamics by revealing the size-dependent and PFT-specific tree mortality patterns,which may inform strategies for maintaining forest diversity and resilience in temperate forest ecosystems.

Legacy effects of historical woodland changes on contemporary plant functional composition

Considering the legacy of plant functional composition can help assess ecosystem functions and ecosystem services across different spatial scales under land cover changes.Woody plants likely respond to natural and anthropogenic perturbations due to historical events(e.g.,agricultural development),thus contemporary plant functional composition may be explained by historical woodland change,a type of land cover change.We propose that historical woodland changes may have legacy effects on contemporary plant functional composition.Here,we used partial least squares regression and linear mixed model analyses to test this assumption by coupling data on community weighted means(CWM)and community weighted variance(CWV)of vegetation plots and calculating the time of woodland existence across different periods from AD 0 to 2017.We found that the legacy effects of historical land cover changes on CWM and CWV during the existence time of woodland,particularly from AD 0 to 900,were drivers of contemporary plant functional composition at large spatial scales.Furthermore,historical woodland changes can affect contemporary plant functional composition,depending on the biome type.Particularly,the CWM of plant height,seed mass,and seed length showed the strongest correlations with woodland changes from AD 1910 to 2010 in tropics with year-round rain,and the CWM of leaf traits correlated with woodland changes from AD 0 to 1700 in tropics with summer rain.Our study provides the effective evidence on the legacy of historical woodland changes and the effects on contemporary plant functional composition,which is crucial with respect to effective management of plant diversity and assessing ecosystem functions and services from local to global scales over time.

Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?

The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion.

Classification of plant functional types based on the nutrition traits： a case study on alpine meadow community in the Zoigê Plateau

The ecological concept of Plant Functional Types（PFTs）, which refers to the assemblage of plants with certain functional traits, has been introduced for the study of plant responses to the environment change and human disturbance. Taking the alpine meadow community in the Zoigê Plateau as a study case, this paper classified PFTs in terms of plant nutrition traits. The sequential results are as follows.（1） The main herbages in the Zoigê Plateau included 16 species in 5 families. Among the five families, Cyperaceae vegetation accounted for 81.37%of herbage area in total, while the remaining 4families occupied less than 20%. As for the species,Kobresia setchwanensis Hand.-Maizz. was dominant,accounting for 48.74% of the total area; while the remaining 51.26% was comprised of Polygonum viviparum L., Anaphalis fiavescens Hand.-Mazz.,Stipa aliena Keng and other species.（2） By using the Principal Component Analysis（PCA）, the assessment of herbages nutrition was carried out based on the comprehensive multi-index evaluation model.Polygonum viviparum L. had the highest nutritional value score（1.43）, and Stipa aliena Keng had the lowest（-1.40）. Nutritional value of herbage species had a significantly positive correlation with altitude（P＆lt;0.01） in the Zoigê Plateau.（3） Based on the nutritional values, herbages in the Zoigê Plateau could be grouped into 3 nutrition PFTs（high, medium and low） by using the Natural Breaks（Jenks） method.

Thriving green havens in baking deserts:Plant diversity and species composition of urban plantations in the Sahara Desert

Hot arid zones represent vital reservoirs of unique species and ecosystems,holding significant importance for biodiversity.This study aimed to explore the plant diversity associated with tree plantations in urban ecosystems under hyper-arid climatic conditions in the Sahara Desert of Algeria.In May 2022,30 quadrats measuring 1 m^(2) each were established at the base of Phoenix dactylifera,Leucaena leucocephala,and Tamarix aphylla,corresponding to the dominant tree species in each of three plantations.In each quadrat,the plant quantitative inventory was conducted to measure plant diversity and similarity among the studied plantations.Based on this,we assessed the plant functional traits and rarity/abundance status of the flora.The findings revealed a diverse flora associated with the studied plantations,comprising 29 plant species grouped into 27 genera and 12 families.Notably,Poaceae(accounting for 30.8% of the flora),Asteraceae(25.0%),and Zygophyllaceae(21.6%)were well-represented.With an overall density of approximately 555 individuals/m^(2),Zygophyllum album(120 individuals/m^(2))and Polypogon monspeliensis(87 individuals/m^(2))emerged as the most abundant species.Functional trait analysis underscored the pivotal role of therophytes(constituting over 50.0% of the flora)and anemochorous species(33.0%-62.5%).Phytogeographic analysis emphasized the prevalence of the Saharo-Arabic element(constituting over 31.0% of the flora)and the Mediterranean Saharo-Arabic element(9.5%-21.5%).The Cosmopolitan element thrived under disturbance factors,recording percentages from 13.0% to 20.0% of the plant community.The rarity/abundance status of the flora emphasized the significance of rare,common,and very common species in the studied plantations.These findings could provide fundamental data for the effective control and management of biodiversity in hot hyper-arid urban ecosystems.

Host plant traits play a crucial role in shaping the composition of epiphytic microbiota in the arid desert,Northwest China

Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and productivity.Nonetheless,the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains ambiguous.Utilizing high-throughput sequencing technology,this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms(e.g.,bacteria and fungi)of various plant life forms in the hinterland of the Gurbantunggut Desert,Northwest China.Functional annotation of prokaryotic taxa(FAPROTAX)and fungi function guild(FUNGuild)were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial communities.Result showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants,with Proteobacteria,Cyanobacteria,and Actinobacteriota dominating bacterial community,while Ascomycota and Basidiomycota were prevalent in fungal community.Comparison across different plant life forms highlighted distinct microbial communities,indicating strong filtering effects by plant characteristics.FAPROTAX prediction identified intracellular parasites(accounting for 27.44%of bacterial community abundance),chemoheterotrophy(10.12%),and phototrophy(17.41%)as the main functions of epiphytic bacteria on leaves of different life form plants.FUNGuild prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs(81.77%),Pathotrophs(17.41%),and Symbiotrophs(0.82%).Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial taxa.Raup-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community assembly.Variance partitioning analysis and random forest modeling suggested that plant leaf functional traits significantly impacted both bacterial and fungal community composition,with fungal community composition showing a closer association with leaf nutrients and physiology compared with bacterial community composition.The distinct responses of bacterial and fungal communities to plant traits were attributed to the differing properties of bacteria and fungi,such as bacteria having higher potential dispersal rates and broader ecological niches than fungi.Overall,the results indicate that phyllosphere bacterial and fungal communities undergo similar community assembly processes,with fungi being more influenced by plant characteristics than bacteria.These findings offer novel insights into the ecology of phyllosphere microbial communities of desert plants.

Effects of Plant Functional Types,Climate and Soil Nitrogen on Leaf Nitrogen along the North-South Transect of Eastern China

We conducted a systematic census of leaf N for 102 plant species at 112 research sites along the North-South Transect of Eastern China （NSTEC） following the same protocol, to explore how plant functional types （PFTs） and environmental factors affect the spatial pattern of leaf N. The results showed that mean leaf N was 17.7 mg g^-1 for all plant species. The highest and lowest leaf N were found in deciduous-broadleaf and evergreen-conifer species, respectively, and the ranking of leaf N from high to low was： deciduous 〉 evergreen species, broadleaf 〉 coniferous species, shrubs ≈ trees 〉 grasses. For all data pooled, leaf N showed a convex quadratic response to mean annual temperature （MAT）, and a negative linear relationship with mean annual precipitation （MAP）, but a positive linear relationship with soil nitrogen concentration （Nsoil）. These patterns were similar when PFTs were examined individually. Importantly, PFTs, climate and Nsoil, jointly explained 46.1% of the spatial variation in leaf N, of which the independent explanatory powers of PFTs, climate and Nsoil, were 15.6%, 2.3% and 4.7%, respectively. Our findings suggest that leaf N is regulated by climate and Nsoil, mainly via plant species composition. The wide scale empirical relationships developed here are useful for understanding and modeling of the effects of PFTs and environmental factors on leaf N.

Projections of land use changes under the plant functional type classification in different SSP-RCP scenarios in China

Land use projections are crucial for climate models to forecast the impacts of land use changes on the Earth’s system.However,the spatial resolution of existing global land use projections(e.g.,0.25°×0.25°in the Land-Use Harmonization(LUH2)datasets)is still too coarse to drive regional climate models and assess mitigation effectiveness at regional and local scales.To generate a high-resolution land use product with the newest integrated scenarios of the shared socioeconomic pathways and the representative concentration pathways(SSPs-RCPs)for various regional climate studies in China,here we first conduct land use simulations with a newly developed Future Land Uses Simulation(FLUS)model based on the trajectories of land use demands extracted from the LUH2 datasets.On this basis,a new set of land use projections under the plant functional type(PFT)classification,with a temporal resolution of 5 years and a spatial resolution of 5 km,in eight SSP-RCP scenarios from 2015 to 2100 in China is produced.The results show that differences in land use dynamics under different SSP-RCP scenarios are jointly affected by global assumptions and national policies.Furthermore,with improved spatial resolution,the data produced in this study can sufficiently describe the details of land use distribution and better capture the spatial heterogeneity of different land use types at the regional scale.We highlight that these new land use projections at the PFT level have a strong potential for reducing uncertainty in the simulation of regional climate models with finer spatial resolutions.

Trait-based representation of hydrological functional properties of plants in weather and ecosystem models

Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types(PFTs)and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.

Variations in the Volatile Organic Compound Emission Potential of Plant Functional Groups in the Temperate Grassland Vegetation of Inner Mongolia, China

Abstract: The biogenic volatile organic compounds (VOC) emitted by the vegetation of a terrestrial ecosystem play a key role in both regional air quality and tropospheric chemistry. To describe the general emission properties of VOC of different plant functional groups (PFG) in a typical temperate grassland in Inner Mongolia, China, we randomly selected 175 plant species and measured the quantities of isoprene and monoterpene in situ. Results showed that most plants had low VOC emission potential at the species level, especially for some dominant plants, such as Leymus chinensis Tzvel., Stipa grandis Smirn., and Agropyron cristatum Gaertn. At the PFG level, the lowest VOC emission potential was found for perennial rhizome grasses, a major PFG in a typical temperate grassland ecosystem. The effects of overgrazing and subsequent vegetation succession on the emission of VOC by different plant life form functional groups (PLFG) were also discussed.

Functions and Application Principles of Indoor Ornamental Plants

Characteristics,categories and functions of indoor ornamental plants were introduced in this study,and application principles were analyzed.

Plant functional groups mediate effects of climate and soil factors on species richness and community biomass in grasslands of Mongolian Plateau

Aims Functional group composition of a plant community is mainly driven by environmental factors and is one of the main determinants of grassland biodiversity and productivity.Therefore,it is important to understand the role of plant functional groups(PFGs)in mediating the impact of environmental conditions on ecosystem functions and biodiversity.Methods We measured plant biomass and species richness(SR)of grasslands in 65 sites on the Mongolian Plateau and classified 157 perennial herbaceous plants into two main PFGs(namely grasses and forbs).Using the random forest model and ordinary least squares regression,we identified that environmental factors(i.e.aridity index,soil total nitrogen[STN]and pH)were significantly related to the SR and aboveground biomass(AGB)of PFGs.We then used structural equation modeling to explore the relationship between the identified environmental factors and community SR and biomass,and the role of PFGs in driving this relationship.Important Findings We found that aridity index had unimodal relationships with both AGB and SR of the PFGs and the whole community.All SR and biomass metrics were significantly related to STN and pH.The relationship between aridity index and community biomass was mediated by an increase in the AGB of grasses.The influence of STN and pH on community SR was mainly due to their regulation in the SR of forbs.Our results indicate that community composition and the identity of the PFGs play a key role in linking environmental factors to ecosystem functioning.

Plant functional traits and microbes vary with position on striped periglacial patterned ground at Glacier National Park, Montana

The retreating snowfields and glaciers of Glacier National Park, Montana, USA, present alpine plants with changes in habitat and hydrology. The adjacent and relic periglacial patterned ground consists of solifluction terraces of green, vegetation-rich stripes alternating with sparsely vegetated brown stripes. We established georeferenced transects on striped periglacial patterned ground for long-term monitoring and data collection on species distribution and plant functional traits at Siyeh Pass and at Piegan Pass at Glacier National Park. We documented species distribution and calculated the relative percent cover(RPC) of qualitative functional traits and used 16 S rRNA from soil samples to characterize microbial distribution on green and brown stripes. Plant species distribution varied significantly and there were key differences in microbial distribution between the green and brown stripes. The rare arctic-alpine plants Draba macounii, Papaver pygmaeum, and Sagina nivalis were restricted to brown stripes, where the RPC of xeromorphic taprooted species was significantly higher at the leading edge of the Siyeh Pass snowfield. Brown stripes had a higher percentage of the thermophilic bacteria Thermacetogenium and Thermoflavimicrobium. Green stripes were co-dominated by the adventitiously-rooted dwarf shrubs Salix arctica and the possibly N-fixing Dryas octopetala. Green stripes were inhabited by Krummholz and seedlings of Abies lasiocarpa and Pinus albicaulus. Prosthecobacter, a hydrophilic bacterial genus, was more abundant on the green stripes, which had 6,524 bacterial sequences in comparison to the 1,183 sequences from the brown stripes. While further research can determine which functional traits are critical for these plants, knowledge of the current distribution of plant species and their functional traits can be used in predictive models of the responses of alpine plants to disappearing snowfields and glaciers. This research is important in conservation of rare arctic-alpine species on periglacial patterned ground.

Features on N/P ratio of plants with different functional groups between two types of steppe in semi-arid area

The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type,carbon metabolism pathway,root type and phylogenetic type,we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai(typical grassland zone)of Zhenglan Banner,Inner Mongolia,China and 91 species in the Habahu National Nature Reserve(desertified grassland zone)in Yanchi County of Ningxia,China.The results show that the N/P ratio(16.91)of C3 plants in the desertified steppe was significantly larger than that(12.72)in the typical steppe,but there was no significant difference between the N/P ratios of C4 plants in the two zones.There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone.Similarly,the N/P ratio(16.60)of dicotyledons in desertified steppe were significantly higher than that(12.98)in typical steppe,while differences in N/P ratios between monocotyledonous plants of the two zones was not significant,and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone.The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe,but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe.Thus,different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants,and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community.

Functions, Selection and Collocation of Greening Plants in the Construction of Ecological Roads

From the perspective of ecological construction of roads, the reduction and purifying effects of greening plants on noise, raising dust and automobile exhaust, selection principles of arbors, shrubs, ground cover plants and herbaceous fl owers, and the methods of collocating arbors shrubs and grass in the construction of ecological roads were discussed in this study.

Unit 1 of Ling’ao Nuclear Power Plant phase II underwent hot functional test successfully

On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for

甘南高寒草甸退化对植物功能群物种多样性与物种多度分布的影响

【目的】探究甘南高寒草甸植物功能群多样性及其物种多度分布对退化的响应,分析随退化程度的加深不同植物功能群的群落构建机理及资源利用方式。【方法】研究以甘南高寒草甸为对象,采用样地调查法收集数据,使用物种多度模型对其进行拟合分析,并采用双向聚类分析对群落物种进行分类。【结果】随着退化程度的加深,植被优势种以禾本科和莎草科植物为主,逐渐变为杂类草功能群植物为主,杂类草功能群在群落多样性分布中起主导作用;全部物种多度分布随着退化程度的加深发生变化,其中,无退化草甸的最优拟合模型是VOLKOV,轻度退化草甸的最优拟合模型是GEO,中度退化草甸和重度退化草甸的最优拟合模型为BRO,资源分配模式由随机分配转向固定分配的分配模式;禾草功能群的最优拟合模型以生态位模型为主,资源分配方式由固定分配和随机分配共同主导,豆科功能群的最优拟合模型是BRO,资源分配方式以固定分配为主,杂类草功能群的最优拟合模型从中性模型向生态位模型转变,与全部物种多度分布的最优模型基本一致,且资源分配由随机分配向固定分配转变。【结论】杂类草功能群是影响群落物种多度分布的主要原因,但是禾草和豆科功能群的贡献也不可忽视。

Biological Function of REE in Plants & Microbes

Rare earth elements （REE） and their compounds years. The bioinorganic chemical research of REE during the are widely applied in agronomic and medical fields for many past few years indicates that REE play important roles in the promotion of photosynthetic rate as well as root absorption, regulation of hormone and nitrogen metabolism, and suppression of microbes, etc. The metallic or non-metallic targets of key biomolecule in various physiological processes can be chosen by REE for the chelation or replacement, which enables REE to regulate the biological functions or behaviors of those biomolecule and consequently leads to significant embodiment of biological function of REE in plants and microbes. Overdose of REE, however, shows an inhibitory effect on living organisms. Therefore, this paper proposes two suggestions that will be available in the extension of full use of REE＇s biological function. One is to obey the dose law of REE and control REE concentrations within a safe range. The other is to further test the bioaccumulation and long-period influence of REE on organisms.

基于植物功能群的生态系统服务形成与维持机制研究

生态系统可以从“结构-功能-服务”3个层次来理解,其中服务是人类的主观感受或效用。维持高质量的生态系统服务还需从生态系统的自然属性入手。结构和功能是生态系统服务形成和维持的内在机制,而植物是生态系统结构和功能的核心驱动力。植物功能群具有特定功能的植物组合,其中优势植物功能群控制着生态系统的结构和功能。生态系统服务的概念、分类与植物功能群密切相关,植物功能群是生态系统与生态系统服务间更直接的桥梁。建立生态系统服务与植物功能群间的联系,使相关研究有更明确的指向,在深化理论研究的同时使研究成果更容易落地。生态系统服务的形成、维持机制与植物功能群的内在联系主要体现在4个主要方面:(1)植物功能群的内在适应性特征和外在效应是生态系统服务形成的基础;(2)植物功能群的多功能特性为生态系统服务协同提供了可能;(3)植物功能群间替代和互补效应可以提升生态系统服务质量和稳定性;(4)植物功能群能够提供基于自然的生态系统服务修复问题解决方案。