Prediction of the joint impacts of sea level rise and land development on distribution patterns of mangrove communities

Mangrove distribution along shorelines shows distinct zonation patterns;thus,different communities may face various influences from sea level rise(SLR)and land use.However,long-term change predictions are usually based only on the total extent of mangroves.Few studies have revealed how SLR and land development such as agriculture,aquaculture,and urbanization jointly affect different intertidal mangrove communities.This study proposed a novel framework combining SLAMM(Sea Level Affecting Marshes Model)and the CLUE-S(Conversion of Land Use and its Effect at Small regional extent)model to assess the potential impacts on upper and lower intertidal mangrove communities.Maoweihai in Guangxi,China,was selected as the study area and the potential impacts from the squeeze effect and mangrove expansion potential were evaluated.We established three scenarios combining SLR and land use patterns to predict mangrove coverage projections by 2070.The results showed that,under a single SLR driver,the upper intertidal mangroves would be more adaptive to rapid SLR than the lower intertidal mangroves.However,under the combined influence of the two drivers,the upper intertidal mangroves would experience larger squeeze effects than the lower intertidal mangroves,with up to 80.5%of suitable habitat lost.Moreover,the expansion potential of upper intertidal mangroves would be considerably more limited than that of lower intertidal mangroves.The length of the expandable habitat patch boundary of upper intertidal mangroves only reached 1.4–1.8 km,while that of the lower intertidal mangroves reached up to99.2–111.2 km.Further,we found that aquaculture ponds and cropland are the top two land development types that could occupy suitable habitat and restrict the mangrove expansion potential.Our results highlight that timely improvement of land use policies to create available landward accommodation space for mangrove migration is essential to maintain the coverage and diversity of mangrove communities under SLR.The proposed method can be a helpful tool for adaptive mangrove conservation and management under climate change.

Research on the Construction Status of the Beijing-Tianjin-Hebei Medical Talent Community and the Countermeasures for Its Realization

In April 2015,the Political Bureau of the CPC Central Committee adopted the“Outline of the Plan for the Coordinated Development of Beijing,Tianjin,and Hebei.”In July 2017,the“Plan for the Integrated Development of Beijing,Tianjin,and Hebei Talents(2017–2030),”jointly prepared by the leading groups of the three regions,was officially released.The core of the coordinated development of these three regions is the orderly removal of non-capital functions from Beijing.Talents,especially medical talents,are integral to this transition.The construction of a medical talent community across these three regions promotes the further development of a healthier China,meets the growing needs of the people for a better life,and embodies the concept of putting people first.This paper begins by examining the current situation of the construction of the Beijing-Tianjin-Hebei medical talent community,reviewing the progress made,analyzing existing problems,and proposing targeted countermeasures and suggestions.

Effect of nutrient level on phytoplankton community structure in different water bodies

Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and dams, in recent years an increasing number of river systems in China have suffered serious algal blooms. The community structure of phytoplankton may differ, however, dependent on the hydrodynamic conditions and nutrient levels within the water body. The field investigation results obtained from a stagnant river in Suzhou City and Taihu Lake, China, showed that in water with higher concentrations of nitrogen and phosphorus, Chlorophyta became the predominant species and in water with lower concentrations of nitrogen and phosphorus, Cyanobacteria became the predominant species. Growth experiments with competitive species, Microcystis aeruginosa Kutz and Scenedesmus quadricauda （Turp.）, were conducted at three different nutrient levels. The biomass of algae in pure and mixed cultures was measured under conditions of different N/P ratios at oligotrophic, eutrophic and hypertrophic nutrient levels. The results indicated that the most suitable state for the growth and reproduction of M. aeruginosa and S. quadricauda were eutrophic conditions in both pure and mixed cultures. Under competition, however, the lower medium nutrient levels favoured M. aeruginosa, while the higher medium nutrient levels better suited S. quadricauda. Under similar hydrodynamic conditions, the community structure of phytoplankton in the water body was determined by the dominant species in competition for nutrients.

Paleocommunity Replacements of Benthic Brachiopod in the Middle-Upper Devonian in the Longmenshan Area,Southwestern China:Responses to Sea Level Fluctuations

Twelve paleocommunities dominated by benthic brachiopod are recognized in the Givetian-Frasnian stages of the Devonian in the Longmenshan area, southwestern China, in which two kinds of brachiopod community replacement are classified. One is the abrupt replacement, represented by abrupt alternation between the Leiorhynchus community and Zhonghuacoelia-Striatopugnax community in the Frasnian Tuqiaozi Formation. The other is the gradual one, developed in the Givetian Guanwushan Formation, which had been completed by the shift of the Independatrypa lemma-Uncinulus heterocostellis-Emanuella takwanensis community via the Sinospongophyllum irregulare-Pseudomicroplasma fongi community to the Clathrocoilona spissa-Hexagonaria composite reef community. According to analyses of the paleocommunities, either the abrupt or gradual paleocommunity replacement of the Middle-Upper Devonian in the Longmenshan area is suggested as a response to the 5th-order sea level fluctuation due to the replacements of the paleocommunities in a tracts-system of depositional sequence. It is supposed that changes of paleocommunity diversity, one of the results of paleocommunity replacement, are depended on the range and magnitude of sea level fluctuation, but there is not a linear relationship between them. Furthermore, a suggestion is proposed that the concept of paleocommunity succession seem to be abandoned in the paleocommunity analysis because it almost never be practiced to recover the information of community succession in the geological record at present.

Correlation between the avian community and habitat at different water levels during spring migration in Zhalong National Nature Reserve,China

Zhalong National Nature Reserve （Zhalong） is an important stopover for migratory birds. In recent decades, Zhalong has become the focus of researchers and public discussion in relation to irrigation. We studied relationships between birds and habitats at different water levels to guide development of more effective habitat management measures. We used line transects to survey bird numbers and distribution during April-May from 2005-2009 at Zhalong, and used cluster analysis and Chi-Square tests to analyze data. We recorded 139 bird species of 39 families and 13 orders during spring migration, including Anseriformes, Charadriiformes, Ciconiiformes, Columbiformes, Coraciiformes, Cucu- liformes, Falconiformes, Galliformes, Gruiformes, Passeriformes, Pici- formes, Podicipediformes, Strigiformes. Dominant vegetation and geo- graphic region were the main influence factors of avian distribution. Different ecological groups preferred different water levels （p〈0.01） and different habitat types （p〈0.01）. Grallatores, Natatores and Passeres were the main ecological groups in different wetland habitats, and reed marsh and lake are the main habitats for management. Grallatores preferred reed marsh and lake with water levels 〉30 cm and 5-15 cm. Natatores preferred lakes with deep water （〉30 cm）. Passeres preferred open forest and reed marsh with no surface water. Different avian ecological groups occupied specific habitats depending on water level and we recorded some overlaps in bird distribution.

Epidemiologic surve of blood lipid level among 1401 residents aged≥60 years in rong-gui community

Objectives To investigate prevalence of blood lipid level among 1401 residents aged≥60 years in rong-gui community.Methods 1401 ones(579 males,822 females, (68.12±6.64)years Of total 1503 residents aged≥60 years in the 2 villages which were randomly exampled in rong-gui community were investigated.867 ones aged among 60-69 years(61.9%),430 ones aged among 70-79 years (30.7%),104 ones aged≥60 years(7.4%).Investigative items included age,sex,total cholesterol(TC),triglyceride (TG),body height,body weight,waist circumference(WC), hip circumference(HC),fasting plasma glucose(FG),blood pressure,history of past illness,body mass index(BMI), waist hip ratio(WHR),waist height ratio(WHtR).Results (l)Of total 1401 residents,Prevalence of hyperlipemia were 42.8%,female were signifleanfly higher than male(P【0.01), The difference among three age groups were not significant, the combined prevalence of hyperlipemia and borderline hyperlipemia was 80.1%.(2)The FG、BMI、SBP、DBP、WC、WHR、WHtR of residents with hyperlipemia were higher than ones with normal blood lipid level(P【0.01).(3)By Pearson correlation analysis,we found that hyperlipemia was obviously correlated with FG,BMI,WC,WHR,WHtR, SBP,DBP.Conclusions(1)Prevalence of hyperlipemia were 42.8%,female were signifleanfly higher than male.(2) hyperlipemia were obviously correlated with higher FG、BMI、WC、WHR、WHtR、SBP、DBP.

Decadal variations in the community status of economically important invertebrates in the Bohai Sea

With the decline of fish stocks,the proportions of economically important invertebrates like crustaceans and cephalopods have increased in the Bohai Sea.The community structure and trophic level of economically important invertebrates were analyzed using the bottom trawl survey data collected by the Yellow Sea Fisheries Research Institute in the Bohai Sea in May and August of 1958–1959,1982,1992–1993,2004,2009 and 2015.A total of 37 species of economically important invertebrates,belonging to 5 orders,24 families,were captured.The biomass densities of economically important invertebrates in the Bohai Sea displayed an overall downward trend from 1982 to 2015.Oratosquilla oratoria and Loligo spp.were the most dominant species in the past 30 years,the biomass proportion of O.oratoria increased gradually in both May and August from 1982 to 2015.Moreover,biodiversity indices of economically important invertebrates in the Bohai Sea appeared to decline from 1982 to 2004 and then increased in 2015.Similarly,the mean trophic level of economically important invertebrates declined from 1982 to 2004 and increased slightly in 2015.Overall,although the proportions of invertebrates have increased,the biomass densities in the Bohai Sea have displayed an overall downward trend from 1982 to 2015.The increases in the biodiversity and trophic level of economically important invertebrates after the 2000s,possibly benefit from stock enhancement projects implemented by governments at different levels and national fishery management measures such as the“double-control”of the total number and engine power of fishing vessels and summer moratorium of fishing.

A Comparative Study of the Microbial Communities Between the Mineral Surface and the Bioleaching Solution Using the Microarray Method

In order to explore the bioleaching mechanism and improve the bioleaching efficiency,the micro-bial community in the bioleaching solution was compared with that on the surface of minerals based on the microarray analysis.Meanwhile,the elements composition in the bioleaching solution was analyzed using the ICP-AES method.Results showed that there was a high concentration of S and Cu in the leaching solution which up to 2 380 mg/L and 1 378 mg/L,respectively,after continuously bioleaching of copper-ore concen-trate for 30 days by a mixed culture associated with 12 species of bioleaching microorganisms.Based on the data of microarray,the total of cell number in the surface of minerals was far higher than that in the bi-oleaching solution.Furthermore,the dominant communities on the surface of minerals,such as Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans and Acidithiobacillus caldus,were similar to that in the bioleaching solution.However,the relative level of some bacteria,such as Sulfobacillus aci-dophilus and Sulfobacillus thermosulfidooxidans,showed great discrepancy with lower presence in the bi-oleaching solution with respect to the mineral surface.

Annual pattern of zooplankton communities and their environmental response in a subtropical maritime channel system in the northern Bay of Bengal, Bangladesh

Zooplankton plays an important role in aquatic food webs by fluxing of energy from primary producer to subsequent trophic levels in the food chain. The annual pattern of zooplankton communities and potential environmental drivers were studied in the Kohelia channel, Bangladesh from summer 2014 to spring 2015.Samples were collected using net at a depth of 1 m. A total of 32 species belonged to 18 orders, 27 families and 15 taxonomic groups were identified. Of these species, 22 distributed in all four seasons of which 8 were dominant and highly contributing to the total communities. Species number peaked in summer next to winter and fall in spring while maximum abundance was in summer and minimum in spring. Multivariate analyses showed that there was a clear annual pattern in the zooplankton communities. Species diversity and evenness peaked in spring but fall in autumn while the high value of species richness was found in winter. Biological-environmental best matching（BIO-ENV） analyses conformed that community pattern of zooplankton was mainly driven by transparency salinity, and temperature individually or combined with water nutrients. These results demonstrate that annual pattern of the zooplankton community shaped by channel environmental factors in subtropical channel ecosystems, thus might be used for community-based subtropical coastal water bioassessment.

Responses of acrocarpous moss communities to heavy metal(Fe,Mn,Cd)and sulfur pollution in the Changgou carbonate manganese ore,SW China

Bryophyte communities have been widely used to monitor and assess heavy metal pollution in soil,air and water.However,the unique value of acrocarpous moss in monitoring environmental pollution and the harm of non-metallic sulfur to human health caused by carbonate manganese mining were seldom considered in previous studies.This study investigated the heavy metal and sulfur pollution level by soil and moss sample collection in Changgou manganese ore and its surrounding environment in the Zunyi area,Guizhou Province,China.By means of cluster analysis,diversity analysis,correlation analysis and redundancy analysis,the relationship between dominant moss communities and major pollutants were analyzed.The results showed that there were pollutants such as iron(Fe),manganese(Mn),cadmium(Cd),sulfur(S)and others in the 500 meters buffer zone centered on Changgou manganese ore.The ore sorting area and waste rock accumulation area were considered as the most seriously polluted,followed by the ore outlet area and ore transport line,at last the miners’living area and vegetable planting area were the least polluted.A total of 23 species of moss communities were identified in the Changgou manganese ore area,among which 9 were dominant,including Bryum blindii Bruch&Schimp.(Bry.bli),Weissia planifolia Dix(Wei.pla)-Bry.bli,Bryum caespiticium Hedw.(Bry.cae),Bryum pallescens Schleicher ex Schw?gr.(Bry.pal),Didymodon longicostatus X.J.Li et Iwats(Did.lon),Weissia brachycarpa(Nees&Hornsch.)Jur.(Wei.bra),Trichostomum brachydontium Bruch.(Tri.bra),Bryum argenteum Hedw.(Bry.arg)Wei.bra and Bryum algovicum Sendt.ex M?ll.Hal.(Bry.alg),all of which are from the acrocarp species.Bry.cae showed a strong tolerance to S,Did.lon to Fe,Bry.pal to Cd and Bry.bli to Mn.There was a significant correlation between the main polluting elements and the dominant bryophyte community(P<0.05),indicating a high biological indicator value.Together,our results can provide the scientific basis for soil pollution monitoring and human health risk assessment in carbonate manganese mining areas.

Water level fluctuations influence microbial communities and mercury methylation in soils in the Three Gorges Reservoir,China

Reservoirs tend to have enhanced methylmercury（MeHg） concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on the effects of microorganisms in soils for the formation of MeHg during different drying and flooding alternating conditions in the Three Gorges Reservoir（TGR）. This study aimed to understand how water level fluctuations affect soil microbial composition and mercury concentrations, and if such microbial variations are related to Hg methylation. The results showed that MeHg concentrations and the ratios of MeHg to THg（MeHg%） in soils were higher in the seasonally drying and flooding alternating areas（DFAs, 175–155 m） than those in the non-inundated（NIAs, 〉 175 m） and inundated areas（IAs, 〈 145 m）. However, MeHg% in all samples was less than 1%, indicating that the Hg methylation activity in the soils of the TGR was under a low level. 454 highthroughput sequencing of 16 S rRNA gene amplicons showed that soil bacterial abundance and diversity were relatively higher in DFA compared to those in NIA and IA, and microbial community composition varied in these three areas. At the family level, those groups in Deltaproteobacteria and Methanomicrobia that might have many Hg methylators were also showed a higher relative abundance in DFA, which might be the reason for the higher MeHg production in these areas. Overall, our results suggested that seasonally water level fluctuations can enhance the microbial abundance and diversity, as well as MeHg production in the TGR.

Effects of single-tree selection harvesting on hymenopteran and saproxylic insect assemblages in the canopy and understory of northern temperate forests

Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.

Measuring Capacity for Resilience among Coastal Counties of the U. S. Northern Gulf of Mexico Region

Many have voiced concern about the long-term survival of coastal communities in the face of increasingly intense storms and sea level rise. In this study we select indicators of key theoretical concepts from the social-ecological resilience literature, aggregate those indicators into a resilience-capacity index, and calculate an index score for each of the 52 coastal counties of Louisiana, Texas, Mississippi, Alabama and Florida. Building upon Cutter’s Social Vulnerability Index work [1], we use Factor Analysis to combine 43 variables measuring demographics, social capital, economic re- sources, local government actions, and environmental conditions within the counties. Then, we map the counties’ scores to show the spatial distribution of resilience capacities. The counties identified as having the highest resilience capaci- ties include the suburban areas near New Orleans, Louisiana and Tampa, Florida, and the growing beach-tourist com- munities of Alabama and central Florida. Also, we examine whether those counties more active in oil and gas develop- ment and production, part of the region’s “energy coast”, have greater capacity for resilience than other counties in the region. Correlation analyses between the resilience-capacity index scores and two measures of oil and gas industry ac- tivity (total employment and number of business establishments within five industry categories) yielded no statistically significant associations. By aggregating a range of important contextual variables into a single index, the study demonstrates a useful approach for the more systematic examination and comparison of exposure, vulnerability and capacity for resilience among coastal communities.

Human Capital of Family and Social Mobility in Rural Areas-Evidence from China

This research focuses on the impact of family＇s human capital on social mobility in China＇s rural community.Empirical research is conducted based on data from surveying a typical rural community in the past 20 yr.The study indicates that social mobility in rural area is active in the past 20 yr,and the human capital of family,represented by primary labor＇s education level,has played an essential role in mobility of low social class.Meanwhile,socio-economic development and the change of supply and demand in labor market dims the signaling role of degree education,but the impact of occupational training is increasingly remarkable.Therefore,the change from sole degree education to multi-leveled education including occupational education and training is a main way for China＇s rural families in low class to realize social mobility.

Health risk from fluoride exposure of a population in selected areas of Tamil Nadu South India

Prevalence of fluorosis is a public health problem in many states of India.It is necessary to find out the different sources through which fluoride enters human metabolism.Only when the sources are identified,suitable remedial measures can be initiated.This study was attempted to find out the contribution of fluoride from various sources such as drinking water,staple food grains,cooked rice,green leafy vegetables and cow milk in the selected area of the study.Percentage of incidence of fluorosis was estimated using a clinical survey.Calculated community fluorosis index values in all the 22 villages were greater than the accepted index value.Fluoride intake from all manor dietary sources of different age groups such as infants,children,adolescents,adults and aged above 70 was determined.The study revealed that,of all the sources,fluoride contribution from drinking water is significant irrespective of age.Hence,it is advised that people of South India,where there similarity in diet pattern,consume drinking water with lesser fluoride to minimize the debilitating effect of fluoride.The study also recommends to the government authorities concerned with supply to provide water with low fluoride level.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Study on the Effects of Infant Fostering Interventions in Xuhui District,Shanghai

Objective To assess the effects of fostering interventions on the infants and their families through the community. Methods A total of 309 infants born on 1st August, 2003 to 30th August, 2004 and their families were recruited as participants by cluster sampling in Longhua and Kantian sub-districts of Xuhui district, Shanghai. The newborns were randomly assigned to intervention group （156 cases） and control group （153 cases）. The infants and their families will be followed up during 3-year interventions. Results After 6 months＇ intervention, the proportion of infants who could turn over the body in the intervention group （88.46%） was higher than that in control group （75.16%）. The morbidity of upper-respiratory tract infection in intervention group （20.51%） was significantly lower than that in control group （32.68%）. The incidence rates of pneumonia, diarrhea and anemia in intervention group were all lower than that in control group, except for pneumonia, the differences were not significant. Both of the knowledge about how to foster infants and service utility in intervention group were higher than that in control group. Conclusion The fostering interventions through the community promote the prevention and control of infants disease, increase the knowledge level and service util ity of families.

An evaluation of underlying mechanisms for“fishing down marine food webs”

Since the concept of ＂fishing down marine food webs＂ was first proposed in 1998, mean trophic level of fisheries landings（MTL） has become one of the most widely used indicators to assess the impacts of fishing on the integrity of marine ecosystem and guide the policy development by many management agencies. Recent studies suggest that understanding underlying causes for changes in MTL is vital for an appropriate use of MTL as an indicator of fishery sustainability. Based on the landing data compiled by Food and Agriculture Organization（FAO） and trophic information of relevant species in Fishbase, we evaluated MTL trends in 14 FAO fishing areas and analyzed catches of upper and lower trophic level groups under different trends of MTL and found that both the cases of a recovered MTL trend and a generally increasing MTL trend could be accompanied by decreasing catches of lower trophic level species. Further, community structure and exploitation history should be considered in using MTL after excluding species with trophic levels lower than 3.25 to distinguish ＂fishingthrough＂ from ＂fishing-down＂. We conclude that MTL used as an indicator to measure fishery sustainability can benefit from a full consideration of both upper and lower trophic level species and masking effects of community structure and exploitation history.

Association of serum CMPF level with fatty acid metabolism and obesity in community population

Objective To detect the serum level of 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF),a significant metabolite of fish oil,in subjects with normal glucose tolerance (NGT) in local communities,and to investigate the association of CMPF with fatty acid metabolism.Methods A total of 272 NGT participants fromscreening for diabetes in Shanghai in 2013 were enrolled.Anthropometric measurements,biochemical evaluation,and questionnaire interview were performed forall the participants.

Responses of soil microbial communities and functions associated with organic carbon mineralization to nitrogen addition in a Tibetan grassland

Alpine grasslands with a high soil organic carbon(SOC)storage on the Tibetan Plateau are experiencing rapid climate warming and anthropogenic nitrogen(N)deposition;this is expected to substantially increase the soil N availability,which may impact carbon(C)cycling.However,little is known regarding how N enrichment influences soil microbial communities and functions relative to C cycling in this region.We conducted a 4-year field experiment on an alpine grassland to evaluate the effects of four different rates of N addition(0,25,50,and 100 kg N ha^-1 year^-1)on the abundance and community structure(phospholipid fatty acids,PLFAs)of microbes,enzyme activities,and community level physiological profiles(CLPP)in soil.We found that N addition increased the microbial biomass C(MBC)and N(MBN),along with an increased abundance of bacterial PLFAs,especially Gram-negative bacterial PLFAs,with a decreasing ratio of Gram-positive to Gram-negative bacteria.The N addition also stimulated the growth of fungi,especially arbuscular mycorrhizal fungi,reducing the ratio of fungi to bacteria.Microbial functional diversity and activity of enzymes involved in C cycling(β-1,4-glucosidase and phenol oxidase)and N cycling(β-1,4-N-acetyl-glucosaminidase and leucine aminopeptidase)increased after N addition,resulting in a loss of SOC.A meta-analysis showed that the soil C/N ratio was a key factor in the response of oxidase activity to N amendment,suggesting that the responses of soil microbial functions,which are linked to C turnover relative to N input,primarily depended upon the soil C/N ratio.Overall,our findings highlight that N addition has a positive influence on microbial communities and their associated functions,which may reduce soil C storage in alpine grasslands under global change scenarios.

Are some communities of the coastal dune zonation more susceptible to alien plant invasion?

Aims Coastal areas,and in particular coastal dunes,are ecosystems strongly affected by the invasion of alien plants.However,few attempts have ever been made to quantify alien species incidence in different communities along the coastal zonation.This work aims to analyze the distribution of alien plants along the coastal zonation of sandy shores on the Tyrrhenian coast,addressing specifically differences among plant communities in abundance of alien plants.Methods The study was performed on recent dunes(Holocene)of the central western coast of Italy.We selected dune landscapes where invasion processes were particularly evident.Vegetation plots were randomly sampled and through cluster analysis,we identified six plant communities corresponding to the typical zonation described for the Tyrrhenian sandy coast of Central Italy.We evaluated and compared frequency and abundance of invasion in these different communities.Further,we investigated how propagule pressure(measured using as proxy human structures)contributed to the observed invasion patterns.Important Findings We found a relatively low total number of aliens but also a differential distribution pattern and strong abundance of some of the aliens in specific sectors of the vegetation zonation.The perennial community of transition dunes appears most affected by invasion processes,related almost exclusively to the frequent and widespread Carpobrotus aff.acinaciformis.This alien species reaches high cover values,apparently lowering cover of native species of transition dune plant communities.Higher levels of invasion in the transition dune can be partially explained because of greater propagule pressure in this section of the dune profile.Our findings thus have important conservation and management implications since transition dune communities with Crucianella maritima are rare and protected(sensu Habitat 92/43/EEC Directive)along the entire Italian coast.