Research Overview on Urban Plant Community

The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.

Impact of habitat heterogeneity on plant community pattern in Gurbantunggut Desert

This paper reports a geomorphologic landscape investigation, vegetationsurvey and soil sampling at 14 sites across the Gurbantunggut Desert between87°37′09″-88°24′04″E and 44°14′04″-45°41′52″N. The study encountered 8 species of lowtrees and shrubs, 5 of perennial herbs, 8 of annual plants and 48 of ephemeral and ephemeroidplants. These species of plants represent one-third of the species found in the GurbantunggutDesert, and their communities make up a large proportion of desert vegetation with great landscapesignificance. In the investigation we found that the plant communities are accordingly succeededwith the spatial variation of macro-ecoenvironment. Using Principal Component Analysis (PCA) andCorrelation Analysis (CA) we found that the micro-ecoenvironment heterogeneity of aeolian sandysoil's physical and chemical properties such as soil nutrient, soil moisture, soil salt, pH etc.only impacted the diversity of herb synusia (PIEherb) of the desert, with a negative correlation.Meanwhile, the impact of microhabitat on the plant community pattern with an antagonisticinteraction made vegetation's eco-distribution in a temporary equilibrium.

Element cycling in the dominant plant community in the Alpine tundra zone of Changbai Mountains, China

Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.

Plant community and ecological analysis of woodland vegetation in Metema Area,Amhara National Regional State,Northwestern Ethiopia

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia to determine plant community types and species distribution patterns and their relationships with environmental variables, including altitude, pH, cation exchange capacity, electrical conductivity （EC）, and moisture. We used a selective approach with a systematic sampling design. A total of 74 quadrats, each 25m × 25m at intervals of 150-200 m were sampled along the established transect lines. For herbaceous vegetation and soil data collection, five subquadrats each lm x lm were established at the four corners and the center of each quadrat. Three community types were identified using TWINSPAN analysis. All three community types showed high diversity （Shannon-Weiner index）, the highest in community type II at 3.55. The highest similarity coefficient was 0.49 （49%） between community types II and III, reflecting 0.51 （51%） dissimilarity in their species richness. The canonical correspondence ordination diagram revealed that the distribution pattern of community type I was explained by moisture while that of community types III and II was explained by EC and altitude and moisture, respectively. Altitude was the most statistically significant environmental variable, followed by moisture and EC in determining the total variation in species composition and distribution patterns while pH and cation exchange capacity were non significant. In conclusion, we recommend that any intervention should take into account these three discrete community types and their environmental settings to make the intervention more successful.

Topography and soil content contribute to plant community composition and structure in subtropical evergreen-deciduous broadleaved mixed forests

Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative approach to classify plant community types in the subtropical forests of Hubei Province(central China),and then quantified the relative contribution of drivers responsible for variation in species composition and diversity.We classified the subtropical forests in the study area into 12 community types.Of these,species diversity indices of three communities were significantly higher than those of others.In each community type,species richness,abundance,basal area and importance values of evergreen and deciduous species were different.In most community types,deciduous species richness was higher than that of evergreen species.Linear regression analysis showed that the dominant factors that affect species composition in each community type are elevation,slope,aspect,soil nitrogen content,and soil phosphorus content.Furthermore,structural equation modeling analysis showed that the majority of variance in species composition of plant communities can be explained by elevation,aspect,soil water content,litterfall,total nitrogen,and total phosphorus.Thus,the major factors that affect evergreen and deciduous species distribution across the 12 community types in subtropical evergreendeciduous broadleaved mixed forests include elevation,slope and aspect,soil total nitrogen content,soil total phosphorus content,soil available nitrogen content and soil available phosphorus content.

Effects of Plant Community Type on Soil Methane Flux in Semiarid Loess Hilly Region,Central Gansu Province,China

Methane(CH_(4))is an important greenhouse gas second only to CO_(2)in terms of its greenhouse effect.Vegetation plays an important role in controlling soil CH_(4)fluxes,but the spatial variability of soil CH_(4)fluxes during vegetation restoration in Loess Hilly Region(LHR)is not fully understood.The effects of different plant community types[Medicago sativa grassland(MS);Xanthoceras sorbifolium forestland(XS);Caragana korshinskii bushland(CK);Hippophae rhamnoides shrubland(HR);and Stipa bungeana grassland(SB)]on soil CH_(4)flux in LHR were studied via the static chamber technique.The results showed that the five plant community types were sinks of soil CH_(4)in LHR,the plant community type significantly affected the soil CH_(4)flux,and the average CH_(4)uptake from high to low was in SB,HR,CK,MS,and XS.During the whole study period,the soil CH_(4)flux showed similar interannual variation.The maximum absorption of soil CH_(4)appeared in the growing season,while the minimum appeared in winter.Soil CH_(4)uptake was positively correlated with soil temperature and soil moisture.Soil temperature and moisture are important controlling factors for the temporal variability of soil CH_(4)flux.In LHR,the Stipa bungeana grassland is the more suitable plant community type for reducing soil CH_(4)emissions.In the process of vegetation restoration in LHR,the soil CH_(4)absorption potential of different plant community types should be considered,ecological benefits should be taken into account,and vegetation more suitable for mitigating the greenhouse effect should be selected.

Rodent-mediated plant community competition:what happens to the seeds after entering the adjacent stands?

Background:Seed dispersal by scatter-hoarding animals can affect the developmental dynamics of plant communities.However,how animals might participate in plant inter-community competition has rarely been investigated.Forest community junction is an area where the competition between plant communities is most prominent and animal activity is more frequent.At present,little is known about how scatter-hoarding animals might assist competitions by adjacent plant communities.Thus,for 3 years(2015–2017),we tracked the fate of 2880 tagged seeds(Quercus aliena var.acuteserrata,Pinus tabuliformis,and P.armandii seed)placed near an edge where the forest composition changes from a pine forest to an oak forest in northwestern China.Results:We found that the seed fates differed when Quercus and Pinus seeds entered adjacent stands.In contrast to Pinus seeds,acorns that entered pine forests were characterized by higher caching rates and longer dispersal distances.Pinus seeds had the highest probability of being predated(85%)by rodents,and eleven Q.aliena var.acuteserrata seedlings were established in pine forests,although none survived in the later stages.In addition,rodents exhibited obvious selectivity in terms of the microhabitats for the seed caching sites.Conclusions:Seed fates differed when Quercus and Pinus seeds entered adjacent stands.The predation pressure by rodents on the seeds of Pinus species limited the germination of seeds and seedling establishment in oak forests.The different seed fates after their bidirectional dispersal could affect the differences in natural regeneration between pine and oak forests,and they might increase the recruitment rates for oak at the edge of an adjacent community.Rodent-mediated seed dispersal could potential unintentionally affect the competition between plant communities.

Plant Community Characteristics of Trampling Disturbance Kobresia humilis Community along the Road in Naqu,Tibet

The change of plant community character during recovery succession processes of high mountain meadow in Naqu, Tibet, was investigated. The results show that there are 41 plant species in the inventoried quadrates. The high-plants in four big families plays important roles in natural vegetation recovery, while Kobresia play an important role in climax communities. The plant species components changed with each succession stage. The plant species were mainly annual and biennial during the early succession stage, and perennial during the medium; and dominated by Kobresia humilis during the late. Potentilla bifurca and Potentilla tanaletfolia were both found in all stages. The accumulated number of family, genus, and species during the succession process varied quadric with the stages. The main plant community characteristics varied logistically with the succession stages except the height. The community characteristics mainly affected by dominant species which were changed in same rhythms. The biomass under ground was far more than the upground. The plant diversity inflated in the medium stage.

Effects of Grassland Caterpillars on Plant Community Structure of Alpine Kobresia Meadows and Soil Properties

[Objective] To investigate the relationship between the grassland caterpillar with different grades and the structure of alpine Kobresia meadow or soil feature. [Method] A total of 10 plots （20.00 m × 20.00 m） were chosen. In each plot, five smaller plots （5.00 m × 5.00 m） were randomly selected and six sample plots （0.25 m × 0.25 m） were then selected in each smaller plot. The biomass, vegetation height, grasslayer thickness, bare land area, soil moisture and total vegetation cover degree were determined. Data were analyzed statistically by Excel 2003 and SPSS 13.0 software. [ Result] There was a significant difference （P 〈 0.05） between the grassland caterpillars at different hazard grades and the structure of alpine Kobresia meadow or soil properties. [ Conclusion] With the increase of grassland caterpillar density, the plant community structure of alpine Kobresia meadows changes from sedge family-dominant community to the forbs-dominant community.

Plant Community Survey of National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base)

[Objectives] This study was conducted to explore the characteristics of natural grassland plant communities in the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base), so as to provide data reference for local grassland resources. [Methods] June to July, 2022, standard plot site investigation was carried out to investigate vegetation species, relative height, relative coverage, relative abundance, relative frequency and dominance in the National Photovoltaic and Energy Storage Empirical Experiment Platform in Datong District, Daqing City of Heilongjiang Province, and to analyze plant community structures in the photovoltaic DC field. [Results] The photovoltaic DC field contained 22 species of plants, of which Suaeda salsa was the common species. The dominant species in photovoltaic DC field were Leymus chinensis, Eleocharis intersita, Carex duriuscula and Carex rugurosa. [Conclusions] The dominant vegetation types were Poaceae and Cyperaceae in the natural grassland of the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base).

Health Sequence of Plant Community of Sand-accumulation Belt at the Upwind Edge of Minqin Oasis

A sand-accumulation belt came into being during the process of desert control in recent 60 years at the edge of oasis,especially at the upwind places in desert area in Hexi Corridor of Gansu.Among them,the sand-accumulation belt at the edge of Minqin Oasis is relatively typical and the most complete.The vegetation on the sand-accumulation belt is not only the formation factor of the sand-accumulation belt,but also an important factor to maintain the stability of the sand-accumulation belt.In a certain sense,the health status of the vegetation of the sand-accumulation belt determines the stability of the sand-accumulation belt.In order to analyze the vegetation status of the sand-accumulation belt,the health sequence analysis of the plant community was carried out of sand-accumulation belt at the edge of Minqin Oasis,by setting 11 lines of equal spacing of sand-accumulation belt at the edge of Minqin Oasis,and through the vegetation survey of more than 60 samples.The vegetation on the sand-accumulation belt at the edge of Minqin Oasis is generally unhealthy.But for the health sequence of this study,the health status of vegetation of the sand-accumulation belt formed by artificial sand fixation forest is better than that of vegetation of the sand-accumulation belt formed by natural shrub at the edge of Minqin Oasis.The health status of vegetation of the sand-accumulation belt of mixed forest of arbor and shrub is the worst at the edge of Minqin Oasis.The dominant species Tamarix laxa on the sand-accumulation belt in the lower reaches of the oasis are seriously withered,and their health is the worst.There is potential danger of the sand-accumulation belt being blown and activated.After abandonment of farmland,protection of protection forest and sand-accumulation belt at the edge of farmland in sand area is a new problem,which is worth considering.

The Application of the Concept of"Nearly Natural"Plant Community in the Optimization of Coastal Ecological Space

The overexploitation of the natural environment caused by urbanization makes more and more natural and semi-natural plant communities gradually lack,which causes a lot of irreversible damage to the environment.Therefore,it is very important to carry out ecological environment construction in all fields of urban construction.In this paper,based on theory and method of plant landscape construction under the concept of"nearly natural"plant community,through the investigation and analysis on plant species,distribution,and structural characteristics of plant community in Baguang District of Shenzhen,regional native plant species are summarized,and structural characteristics of original zonal plant community are simulated.The research aims to provide a reference basis for creating a coastal plant landscape with subtropical marine climate for Baguang and even Lingnan,constructing near natural ecological park according to local conditions,forming the pattern well-coordinated with the local natural ecosystem,and carrying out protection of the regional ecological environment.

Impact Factors on Distribution and Characteristics of Natural Plant Community in Reclamation Zones of Changjiang River Estuary

To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).

Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China

The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.

Positive Interactions： Crucial Organizers in a Plant Community

For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive Interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread In nature. In the present paper, we reviewed the mechanism and ecological importance of positive Interactions In plant communities, emphasizing the certainties and uncertainties that have made It an attractive area of research. Positive Interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The Importance of facilitation in plant organization increases with ablotlc stress and the relative Importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive Interactions occur.

Folk nomenclature of plants in Cistanche deserticola-associated community in South Gobi, Mongolia

Cistanche deserticola is an important medicinal plant in Mongolia.Despite its significant role in local healing systems,little traditional knowledge had been reported.The present study investigated folk names of C.deserticola and other species of the same community in Umnugobi Province,South Gobi region of Mongolia,based on ethnobotanical approaches.The high correspondence between folk names and scientific names of plant species occurring in Cistanche-associated community shows the scientific meaning of folk nomenclature and classification in Mongolia.The Mongolian and folk names of plants were formed on the basis of observations and understanding of wild plants including their morphology,phenology and traditional uses as well.Results from this study will support the conservation of C.deserticola itself,a rare and endangered plant species listed in the Monglian Red Data Book.Our documentation of folk nomenclature based on 96 plant species in the Cistanche community,as a part of traditional knowledge associated with biodiversity,will be very helpful for making strategy of plant biodiversity conservation in Mongolia.

Community Structure and Diversity of Ground Cover Plants in Tianjin Binhai International Airport

By using quadrat sampling method, the community structure and diversity of ground cover plants in the flight area in Tianjin Binhai International Airport were investigated from spring to autumn in 2015. The results showed that 58 plant species were recorded at the airport, belonging to 18 families and 48 genera. Dominant plant species showed seasonal characteristics. Specifically, lxeri chinensis （ Thunb. ） Nakai and Lagopsis supina （ Steph. ） Ik. -Gal. ex Knorr. were the dominant species in spring; Lagopsis supina, Cirsium setosum （Willd.） MB, Plantago asiatica L. , Cynanchum chinense R. Br. and Humulus scandens （I_our.） Merr. were the dominant species in summer; Chloris virgata Sw. and Eleusine indica （L.） Gaertn. were the dominant species in autumn. Quantitative characteris- tics of the dominant species, including the density, frequency, coverage and height, varied in different seasons. In different seasons, changes in the diversity of plant communities in three sampling points were analyzed. The results indicated that plant communities in summer exhibited the highest diversity and the most uni- form distribution. This study provided a theoretical basis for avoidance of bird strike in Tianjin Binhai International Airport.

Carry over from previous year environmental conditions alters dominance hierarchy in a prairie plant community

Aims To determine if an experimentally applied anomalous weather year could have effects on species composition and community structure that would carry over into the following year.Methods We conducted a field experiment applying two levels of temperature(ambient and+4
C)and two levels of precipitation(ambient and doubled)and followed cover of plant species during the treatment year and one post-treatment year.Data analysis included ordination analysis,examination of species frequency distributions and comparison of cover of functional groups and individual species.Important Findings A drought during the summer and fall of the treatment year resulted in significant differences in community structure between the 2 years.C3 and winter annual species were depressed in the spring of the second year following the dry autumn.Species richness and legume cover increased in the second,wetter,year.Treatments caused no overall differences in community structure but did alter the dominance hierarchy of species among treatments as well as years.Warming decreased relative cover of winter annuals and early spring-flowering species but increased other annuals.Warming and double precipitation together increased cover of C4 perennial graminoids.In particular,the warming and precipitation treatments both increased the abundance of Andropogon gerardii,not individually altering the dominance hierarchy but together nearly doubling the relative cover of A.gerardii,making it the most abundant species in the combined treatment,while the cover of Bromus arvensis,the former dominant,decreased by 25%.The following year,Andropogon relative cover increased further in the former warmed plots,becoming dominant in both the formerly warmed and warmed plus double precipitation treatments.The year following treatments also saw an increase in relative cover of summer-blooming species in the formerly warmed plots and differences among the former treatments in species richness of functional groups.If the effects of one anomalous year on plant abundance can carry over into the following year,several warm years could have a significant impact on plant community structure.

Understorey plant community assemblage of Australian Eucalyptus woodlands under elevated CO_(2)is modulated by water and phosphorus availability

Aims Given the key functional role of understorey plant communities and the substantial extent of forest cover at the global scale,investigating understorey community responses to elevated CO_(2)(eCO_(2))concentrations,and the role of soil resources in these responses,is important for understanding the ecosystem-level consequences of rising CO_(2)concentrations for forest ecosystems.Here,we evaluated how experimentally manipulating the availabilities of the two most limiting resources in an extremely phosphorus-limited eucalypt woodland in eastern Australia(i.e.water and phosphorus)can modulate the response of the understorey community to eCO_(2)in terms of germination,phenology,cover,community composition and leaf traits.Methods We collected soil containing native soil seed bank to grow experimental understorey plant communities under glasshouse conditions.Important Findings Phosphorus addition increased total plant cover,particularly during the first 4 weeks of growth and under high water conditions,a response driven by the graminoid component of the plant community.However,the treatment differences diminished as the experiment progressed,with all treatments converging at〜80%lant cover after〜11 weeks.In contrast,plant cover was not affected by eCO_(2).Multivariate analyses reflected temporal changes in the composition of plant communities,from pots where bare soil was dominant to high-cover pots dominated by a diverse community.However,both phosphorus addition and the interaction between water availability and CO_(2)affected the temporal trajectory of the plant community during the experiment.eCO_(2)also increased community-level specific leaf area,suggesting that functional adaptation of plant communities to CO_(2)may precede the onset of compositional responses.Given that the response of our seed bank-derived understorey community to CO_(2)developed over time and was mediated by interactions with phosphorus and water availability,our results suggest a limited role of eCO_(2)in shaping plant communities in water-limited systems,particularly where low soil nutrient availability constrains productivity responses.

Plant community and soil properties drive arbuscular mycorrhizal fungal diversity:A case study in tropical forests

The mutual interdependence of plants and arbuscular mycorrhizal fungi(AMF)is important in carbon and mineral nutrient exchange.However,an understanding of how AMF community assemblies vary in different forests and the underlying factors regulating AMF diversity in native tropical forests is largely unknown.We explored the AMF community assembly and the underlying factors regulating AMF diversity in a young(YF)and an old-growth forest(OF)in a tropical area.The results showed that a total of 53 AMF phylogroups(virtual taxa,VTs)were detected,38±1 in the OF and 34±1 in the YF through high-throughput sequencing of 18S rDNA,and AMF community composition was significantly different between the two forests.A structural equation model showed that the forest traits indirectly influenced AMF diversity via the plant community,soil properties and microbes,which explained 44.2%of the total observed variation in AMF diversity.Plant diversity and biomass were the strongest predictors of AMF diversity,indicating that AMF diversity was dominantly regulated by biotic factors at our study sites.Our study indicated that forest community traits have a predictable effect on the AMF community;plant community traits and soil properties are particularly important for determining AMF diversity in tropical forests.