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1.
The recent introduction of Xylella fastidiosa in Europe and its involvement in the Olive Quick Decline Syndrome (OQDS) in Apulia (Salento, Lecce district, South Italy) led us to investigate the biology and transmission ability of the meadow spittlebug, Philaenus spumarius, which was recently demonstrated to transmit X. fastidiosa to periwinkle plants. Four xylem-sap-feeding insect species were found within and bordering olive orchards across Salento during a survey carried out from October 2013 to December 2014: P. spumarius was the most abundant species on non-olive vegetation in olive orchards as well as on olive foliage and was the only species that consistently tested positive for the presence of X. fastidiosa using real-time PCR. P. spumarius, whose nymphs develop within spittle on weeds during the spring, are likely to move from weeds beneath olive trees to olive canopy during the dry period (May to October 2014). The first X. fastidiosa-infective P. spumarius were collected in May from olive canopy: all the individuals previously collected on weeds tested negative for the bacterium. Experiments demonstrated that P. spumarius transmitted X. fastidiosa from infected to uninfected olive plants. Moreover, P. spumarius acquired X. fastidiosa from several host plant species in the field, with the highest acquisition rate from olive, polygala and acacia. Scanning electron microscopy (SEM) revealed bacterial cells resembling X. fastidiosa in the foreguts of adult P. spumarius. The data presented here are essential to plan an effective IPM strategy and limit further spread of the fastidious bacterium.  相似文献   

2.
The unique color pattern polymorphism and the foamy nymphal case of the meadow spittlebug Philaenus spumarius have attracted the attention of scientists for centuries. Nevertheless, since this species has never been considered a major threat to agriculture, biological, ecological and ethological data are missing and rather scattered. To date this knowledge has become of paramount importance, in view of the discovery of P. spumarius main role in the transmission of the bacterium Xylella fastidiosa in Italy, and possibly in other European countries. The aim of this review is to provide a state of the art about this species, with particular focus on those elements that could help developing environmental friendly and sustainable control programs to prevent transmission of X. fastidiosa. Moreover, recent findings on the role of the meadow spittlebug as vector of the fastidious bacterium within the first reported European bacterium outbreak in Apulia (South Italy) will be discussed.  相似文献   

3.
Dothistroma needle blight (DNB), a disease affecting several pine species, is currently generating great concern in Europe. Caused by Dothistroma pini and Dothistroma septosporum, DNB affects pine needles and causes premature defoliation, which results in growth reduction and, in extreme cases, mortality. The disease has increased in importance in Europe over the last 20 years, with an increase in the number of observations of DNB in regions with large areas of Pinus sylvestris in northern Europe. This article presents a cell‐based spatiotemporal model for predicting the likelihood and intensity of the future spread of D. septosporum in Europe. Here, “spread” includes both invasion of new regions and infection of healthy stands within already‐colonized regions. Predicted spread depends on the availability of host species, climatic suitability of different regions to D. septosporum and dispersal of sexual and asexual spores from infected trees to surrounding forests via water splash, mist and wind. Long‐distance spread through transport of infected seedlings is also included in the model. Simulations of spread until 2007 and 2015 were used to validate the model. These simulations produced similar patterns of spread to those observed in Europe. Simulations for 2030 suggested that additional and new outbreaks are likely to occur in Scotland, southern Norway, southern and central Sweden, northern parts of Germany and Poland, Estonia, Latvia and south‐west Finland. Preventing the delivery of infected seedlings would be an effective method for reducing the spread of D. septosporum in the Nordic countries, Scotland and Ireland, the Baltic countries, and parts of Germany, Poland and Belarus. In these states, prevention of transport of infected seedlings can reduce the probability of additional spread by 15%–40%.  相似文献   

4.
Chilo partellus is a major crop pest in Asia and Africa, and has recently spread to the Mediterranean region. Knowledge of its potential distribution can inform biosecurity policies aimed at limiting its further spread and efforts to reduce its impact in areas that are already invaded. Three models of the potential distribution of this insect have been published, each with significant shortcomings. We re-parameterized an existing CLIMEX model to address some parameter inconsistencies and to improve the fit to the known distribution of C. partellus. The resulting model fits the known distribution better than previous models, highlights additional risks in equatorial regions and reduces modelled risks in wet and extremely dry regions. We bring new insights into the role of irrigation in the potential spread of this invasive insect and compare its potential distribution with the present known distribution of its hosts. We also distinguish regions that are suitable for supporting persistent populations from those that may be at risk from ephemeral populations during favourable seasons. We present one of the first demonstrations of a new capability in CLIMEX to automatically estimate parameter sensitivity and model uncertainty. Our CLIMEX model highlights the substantial invasion risk posed by C. partellus to cropping regions in the Americas, Australia, China, Europe, New Zealand and West Africa. Its broad host range and reported impacts suggest that it should be a pest of significant concern to biosecurity agencies in these presently uninvaded regions.  相似文献   

5.
Mediterranean ecosystems are characterized by large arid areas where the patchy distribution of trees offers little protection against harsh climate conditions for seedling establishment. Climate change is predicted to result in an increase in these arid regions, with pronounced effects on vegetation. Production of seedlings with developed ectomycorrhizas is a promising strategy for minimizing the initial transplant shock, thereby increasing plant survival and growth during the first, most critical years of a plantation. One important species in the Mediterranean basin is Quercus suber (cork oak), which occurs, together with other evergreen oak species, in an agro-silvo-pastoral system that represents an example of sustainable land use in Europe. In this study, a Pisolithus tinctorius isolate was used for ectomycorrhizal colonization of cork oak nursery seedlings, and the effects on aboveground plant growth and leaf structural and physiological parameters were investigated. Ectomycorrhizal development resulted in a significant increase in leaf area, dry weight, nitrogen content, and photosynthetic pigments, and mycorrhizal plants showed a higher photosynthetic capacity and water use efficiency. Nursery-inoculated plants established in the field showed increased survival and growth during the first year after transplant. These results indicate a potential for further enhancing the use of mycorrhizal inoculation as a cultivation practice in forest nurseries. Considering the difficulty of soil restoration under limiting environmental conditions, nursery inoculation with ectomycorrhizal fungi can be an important advantage for improving the quality of seedling stock and its performance after out-planting in the field, benefiting the regeneration of arid regions and the reintroduction of inocula of ectomycorrhizal fungi into these areas.  相似文献   

6.
The brown marmorated stinkbug, Halyomorpha halys is a highly polyphagous invasive insect, which has more than 300 reported hosts, including important horticultural crops. It has spread to every Northern Hemisphere continent, most recently to Europe. Whilst there have been no reports of incursions into Southern Hemisphere countries, there have been many interceptions associated with trade and postal goods. We modelled the potential distribution of H. halys using CLIMEX, a process-oriented bioclimatic niche model. The model was validated with independent widespread distribution data in the USA, and more limited data from Europe. The model agreed with all credible distribution data. The few exceptions in the distribution dataset appeared to be transient observations of hitchhikers, or were found at the edge of the range, in regions with topographic relief that was not captured in the climatic datasets used to fit and project the model. There appears to be potential for further spread in North America, particularly in central and southern states of the USA. In Europe, there is substantial potential for further spread, though under historical climate the UK, Ireland, Scandinavia and the Baltic states of Estonia, Lithuania and Latvia appear not to be at risk of establishment of H. halys. In the Southern Hemisphere, regions with moist tropical, sub-tropical, Mediterranean and warm-temperate climates appear to be at substantial risk on each continent. The threats are greatest in prime horticultural production areas.  相似文献   

7.
The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating pest of tomato originating from South America. After its initial detection in eastern Spain in 2006, it rapidly invaded various other European countries and spread throughout the Mediterranean basin. If no control measures are taken, then the pest can cause up to 80–100% yield losses in tomato crops in recently invaded areas and may pose a threat to both greenhouse and open-field tomato production. The exceptional speed and extent of T. absoluta invasion have called for studies documenting its biology and ecology, while indicating an urgent need for efficient and sustainable management methods. The development of approaches to manage T. absoluta would be facilitated through a detailed revision of information on this pest in its area of origin. This review combines information on the invasion by T. absoluta, its ecology, and potential management strategies, including data that may help the implementation of efficient biological control programs. These programs, together with a variety of other management tactics, may allow efficient integrated pest management of T. absoluta in Europe and Mediterranean Basin countries.  相似文献   

8.
An epidemic wood‐decaying fungus, Inonotus rickii, originating from South America, has spread to the Mediterranean area and southern China. We report the first observation of this fungus on Acacia richii in Panzhihua, southern China. It causes serious canker and decay on urban trees in the investigated area. In addition, phylogenetic analysis showed that the fungus from Panzhihua is closely related to isolates from Europe, South America, Mianyang and Hainan of China. Moreover, it was concluded that the isolates of the species previously reported from the USA do not belong to I. rickii.  相似文献   

9.
In regions with a Mediterranean-type climate wildfires are a frequent occurrence: in such environments fire tolerant/favoured species are frequently encountered. In the Mediterranean basin, many species of fire prone habitats are resprouters while others are known to germinate after fire. Fire causes an enhancement of seed germination in many species from fire prone habitats in the other regions with a Mediterranean-type vegetation such as Western Australia, California and South Africa. Seeds of a number of these species are stimulated to germinate by the smoke generated from burning of plant material in either an aerosol or aqueous form. However, for species from the Mediterranean basin the role of smoke in germination is poorly known, despite the fact that in the field many species seems to be encouraged to germinate after fire. We examined the germination of 10 species native to the Mediterranean basin that were treated with aerosol smoke. Some species were from fire prone habitats while others were not. In relation to the controls, increased germination occurred in three of the species (e.g. Cistus incanus), three had more rapid germination but no total increase (e.g. Rhamnus alaternus), two showed reduced germination (e.g. Asphodelus ramosus) and two exhibited no difference in germination (e.g. Clematis flammula). There was additionally no consistent pattern of germination behaviour depending on the habitat from which the species came. Comparison is made between the results of this study and those of other studies on seed germination response to heat and smoke in other areas of Mediterranean-type climate. An understanding of the importance of fire in relation to other disturbances in the vegetation dynamics in the Mediterranean basin needs to be clarified by further detailed studies of the effect of heat and smoke products on seed germination of Mediterranean species. Outcomes of further research, also on a broader range of species, would have important impacts also for conservation, environment management, horticulture and ecosystem restoration.  相似文献   

10.
Since 2001, the incidence of bleeding canker of horse chestnut (Aesculus hippocastanum) has increased markedly in western Europe. The causal agent, the bacterium Pseudomonas syringae pv. aesculi, originally isolated from foliar lesions on Indian horse chestnut (Aesculus indica) in India, is a bark killing pathogen on A. hippocastanum. In this study, P. syringae pv. aesculi was found as a foliar epiphyte on both A. hippocastanum and A. indica trees growing in the UK. When Aesculus leaves were challenged with cell suspensions (109 CFU ml?1) of Pseudomonas syringae pv. aesculi, a high level of asymptomatic infection occurred in all the species tested. The degree of re‐isolation of the bacterium after surface sterilization of leaves ranged from 33% (A. pavia) to 84 and 97% for A. hippocastanum and A. chinensis, respectively. The studies suggest both epiphytic and intrafoliar populations of P. syringae pv. aesculi could play a role in the incidence and spread of bleeding canker of horse chestnut. Growth–temperature responses of P. syringae pv. aesculi indicated a minimum of approximately ?4°C and a maximum of approximately 35°C, with an optimum of approximately 25°C. These findings show that P. syringae pv. aesculi is not restricted to bark lesions but is likely to be widespread in the environment. It is also capable of causing foliar infection of several Aesculus species and could persist under extremes of weather in the UK.  相似文献   

11.
Seiridium cardinale is regarded as the most important agent responsible for the disease of cupressaceous hosts referred to as Cypress canker. The fungus was first described in California and is currently reported in all continents. A recent study based on seven SSR loci has suggested that California populations may represent the source of the epidemic in the Mediterranean. In this study, 185 AFLP markers were used on an expanded sample size of 125 isolates to determine whether the Mediterranean population may indeed be derived from the California one and to compare the reproductive modes of populations in the two regions of the world. Additionally, amova , NJ, STRUCTURE, principal component analysis and β‐tubulin sequence analyses were employed to infer the presence of genetic structure within and between populations. The distribution of pairwise AFLP similarity coefficients suggests Mediterranean populations are reproducing only clonally, while California populations are reproducing both clonally and sexually. amova indicates Mediterranean and California populations are currently genetically isolated, but NJ and STRUCTURE analyses both suggest ancestral Mediterranean genotypes belong to the California population. No alleles were private to either population, and the presence of identical or quasi‐identical genotypes at large distances supports the notion that movement of infected cypress plants is responsible for the global spread of the disease. Surprisingly, STRUCTURE identified a second cluster of Mediterranean genotypes distinct from the basal mixed California–Mediterranean cluster. This second cluster either may have originated from the first one under the selection pressure imposed on the pathogen in the new Mediterranean environments or may be the result of a further introduction from California or elsewhere. Cumulatively, the evidence presented here suggests that S. cardinale may be native or long naturalized in California and that two genetically distinct groups are present in the Mediterranean, with obvious implications for further studies on this disease.  相似文献   

12.
Lecanosticta acicola (Thüm.) Syd., a serious foliage pathogen of pines in many regions of the world, is an emerging invasive species in northern Europe. After the first record of L. acicola on Pinus ponderosa Dougl. ex Laws. in northern Estonia in 2008, monitoring was started to investigate the spread and host range of the fungus in the country. By the beginning of 2015, L. acicola was also recorded on P. uncinata Mill. ex Mirb., P. mugo Turra and on P. mugo var. pumilio (Haenke) Zenari, being the northernmost records of the fungus in Europe. So far, the single native pine species Pinus sylvestris L. has not been found to be infected. Molecular analysis proved infection of L. acicola on pines in five different localities of Estonia: in Tallinn (mainly in the Botanic Garden, northern Estonia), in Tori and Kärdla (western Estonia), in Vasula and Kärevere (east-central Estonia). The sexual state (teleomorph) of the fungus was not found, but the existence of the both mating types, MAT1-1 and MAT1-2, was confirmed.  相似文献   

13.
The Siberian moth, Dendrolimus sibiricus, Tschtv. is the most harmful defoliator of coniferous forests in North Asia. The pest has already spread over the Urals and continues moving westwards. Recently, it has been recommended for quarantine in member countries by European and Mediterranean Plant Protection Organization (EPPO). The performances of the pest on coniferous species planted in Europe were assessed on a range of potted trees corresponding to the spectrum of economically important conifers in the EU: European larch Larix decidua, Norway spruce Picea abies, Scots pine Pinus sylvestris, European black pine Pinus nigra, and the North American species: Douglas fir Pseudotsuga menziesii and grand fir Abies grandis. Larvae showed a potential to survive and complete the development on all these host tree species. Favorable hosts were grand fir, European larch, and Douglas fir that allowed higher survival, better larval development, and as a result, yielded heavier pupae and adult moths with higher longevity. Black pine was a poor host but, however, could still support larval and pupal development. Norway spruce and Scots pine had an intermediate behavior. If accidentally introduced to Europe, the Siberian moth may become especially damaging in forest stands predominated by European larch and by the North American firs. Norway spruce and especially the two-needle pines will be less prone to intensive defoliation by this species. The fact that the pest may damage the range of economically important coniferous species should be taken into account in the pest risk assessment for Europe and also for North America where the Siberian moth occurrence is considered likely.  相似文献   

14.
The objective of this study was to identify climatic factors determining the distribution of a keystone understory taxon, section Crassinodi of the genus Sasa, and assess the impacts of climate change on the taxon. Relationships between the distribution of sect. Crassinodi and five climatic variables were explored using classification tree analysis. Potential habitats under current climate and future climate in 2081–2100 were predicted. Potential habitats were further divided into suitable and marginal habitats. The predictive accuracy of the model was assessed using receiver operating characteristic analysis and by comparing model predictions with an independent dataset. The model was reasonably accurate. It showed that the warmth index (WI) and snow cover were the most important climatic variables for Crassinodi distribution. Potential habitats were limited to cooler regions with WI <102.7°C month. Suitable habitats were limited to even cooler regions with WI <84.8°C month. The model also showed that areas with deeper snow than previously reported would provide suitable habitats for Crassinodi under some climatic conditions. In 2081–2100, 37.4% of current potential habitats are predicted to become non-habitats because of increases in WI. Most currently suitable habitats are predicted to vanish from western Japan by 2081–2100. Meanwhile, Hokkaido and high-elevation areas of eastern Honshu will sustain suitable habitats. Sect. Crassinodi, which is adapted to less snowy climates, is predicted to be more affected by climate change than sect. Sasa and Macrochlamys, which are adapted to snowy climates.  相似文献   

15.

Trioza erytreae is one natural psyllid vector of Candidatus liberibacter, the causal agent of the citrus greening disease (HLB). Since its introduction in 2014 into the Iberian Peninsula, T. erytreae was able to spread continuously toward southern coastal regions of Portugal and northern coastal regions of the Cantabric sea in Spain. Identifying key areas of potential colonization by the psyllid vector is crucial to anticipate derived problems of establishing the disease. This work aimed to find potential areas that could be colonized by T. erytreae throughout the Iberian Peninsula using 1 km spatial data resolution, a physical barrier, long-distance dispersal events (LDEs), and 30 years of simulation. The bioclimatic suitability of Citrus spp. was used as a surrogate of its spatial distribution and a measure of habitat invasibility. Two localities, one in Portugal and one in Spain, were considered as initial points of the spread of T. erytreae. Four spread scenarios were initially simulated, corresponding to very low, low, medium, and high spread. An altitude of 400 m was included in the model as a physical barrier, and cells up to 500 km apart were allowed to be colonized due to LDEs. In this work, three key risk areas were identified, the citrus-growing areas of Setúbal (Portugal) and Huelva (Spain), and the potential corridors that may connect Guipúzcoa, where T. erytreae is already present, with the Ebro valley (Spain). Future modeling and simulation studies should include biological constraints such as the effect of parasitoids on the population of T. erytreae (e.g., Tamarixia dryi) and other barriers or corridors.

  相似文献   

16.
The Mediterranean basin is a fire-prone area and is expected to continue being so according to projected climate and socioeconomic changes. Sustainable exploitation of forest biomass could have a positive effect on wildfire hazard mitigation. A modelling approach was used to compare how four different Scenarios for biomass collection for energy use affect fire behaviour and potential burnt area at landscape level under extreme meteorological conditions in a typical Mediterranean Massif. A case study of Pinus halepensis stands in Valencia (Eastern Spain) was conducted. The FARSITE simulator was used to evaluate the burnt area and fire behaviour parameters. Simulations predicted a significant increase in the burnt area and the values of most fire behaviour parameters in a Scenario of rural abandonment, relative to the current situation. Biomass management through thinning reduced canopy bulk density; however, no differences in the values of the main fire behaviour parameters were detected. Thinning and understory clearing, including biomass collection in large shrub fuel model areas, significantly reduces fire hazard. Forest biomass sustainable harvesting for energy is expected to reduce fire hazard if management includes intense modification of fuel models, comprising management of shrub biomass at the landscape level. Strong modification of forest fuel models requires intensive silvicultural treatments. Therefore, forest biomass collection for energy in the Mediterranean basin reduces fire hazard only if both tree and shrub strata are managed at landscape level.  相似文献   

17.
This study compiles and summarizes the existing knowledge about observed and projected impacts of climate change on forests in Europe. Forests will have to adapt not only to changes in mean climate variables but also to increased variability with greater risk of extreme weather events, such as prolonged drought, storms and floods. Sensitivity, potential impacts, adaptive capacity, and vulnerability to climate change are reviewed for European forests. The most important potential impacts of climate change on forest goods and services are summarized for the Boreal, Temperate Oceanic, Temperate Continental, Mediterranean, and mountainous regions. Especially in northern and western Europe the increasing atmospheric CO2 content and warmer temperatures are expected to result in positive effects on forest growth and wood production, at least in the short–medium term. On the other hand, increasing drought and disturbance risks will cause adverse effects. These negative impacts are very likely to outweigh positive trends in southern and eastern Europe. From west to east, the drought risk increases. In the Mediterranean regions productivity is expected to decline due to strongly increased droughts and fire risks.  相似文献   

18.
The Spanish populations of Juniperus oxycedrus subsp. macrocarpa are restricted to coastal dune habitats of the Mediterranean and Atlantic coasts. Here, we investigate the genetic structure in this taxon and the possible existence of detailed phylogeographic structure associated with the Strait of Gibraltar using data from amplified fragment length polymorphism (AFLP) and plastid markers for 14 populations in three regions: Andalusia, the Valencian Community and the Balearic Islands. Principal coordinate analysis (PCOA) data revealed a lack of clear genetic structure in J. oxycedrus subsp. macrocarpa based on AFLP. The highest AFLP genetic diversity was found in Andalusia. Plastid markers revealed 14 haplotypes, only two of them were shared among the regions. Andalusian populations had the highest number of exclusive haplotypes. Our results support Andalusia as a reservoir of genetic diversity for J. oxycedrus subsp. macrocarpa, and, as for other gymnosperms, this area could be considered as a genetic refugium. The frequent presence of common and exclusive haplotypes in Andalusia might indicate the colonisation of the Spanish Mediterranean coast from the Atlantic populations. Colonisation of these new areas could be promoted by biological factors, such as the existence of long-lived individuals or potential for seed dispersal. Finally, the Strait of Gibraltar did not constitute a natural barrier to the expansion of this species along the coast, as identical haplotypes are found on the Atlantic and Mediterranean coasts.  相似文献   

19.
The fungus Sydowia polyspora is frequently isolated from conifers worldwide and is considered a pathogen on several hosts. Stone pine (Pinus pinea) is one of the most important forestry species throughout the Mediterranean basin due to the value of the edible pine nut. Stone pines showing tip dieback, needles with tan‐ to yellow‐coloured lesions and shoot death, observed in stands in Portugal, were sampled for analysis. Fungal colonies covered with cream‐coloured spore masses, were consistently obtained. Morphological and phylogenetic analyses of the ITS rDNA region enabled identification of these isolates as S. polyspora. Inoculation tests showed that the fungus caused lesions on excised P. pinea shoots. The symptoms observed might have a negative effect on pine nut production, and thus, evaluation of the impact of this disease is of relevance to future research. This paper is the first to report S. polyspora causing disease on P. pinea.  相似文献   

20.
Forecasting the potential impacts of forest policies on species of special conservation value is a prerequisite for safeguarding forest biodiversity. In this study, regional forest policy scenarios were compared in terms of predicted habitats suitable for the Siberian flying squirrel (Pteromys volans). To derive both patch- and landscape-scale models to predict species presence in a forest stand, species occurrence data from a systematic field survey covering the whole distribution area of the flying squirrel in Finland and Multi-Source National Forest Inventory data were combined. Then, the Finnish forestry model MELA and the derived occupancy models were applied to predict the quantity of suitable habitats for flying squirrels in three different 50-year policy scenarios. The results confirm that increasing the utilization of felling potential from the level of business-as-usual to the level stated as policy targets in regional forest programs decreases the amount of suitable habitat in the future. However, regional forest programs had a less drastic impact on habitats than maximum sustainable removal, except in two regions. It should be noted that the occupancy models seemed to fail on sites that experts deem to be most suitable for the species. Obviously, there are other factors than forest management affecting presence.  相似文献   

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