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1.
Glob Chang Biol ; 25(1): 201-217, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30346104

RESUMO

Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to local land-use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global-change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global-change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus excelsior). We sampled trees along spatial environmental gradients across Europe and accounted for the effects of management for Quercus. We collected increment cores from 267 trees distributed over 151 plots in 19 forest regions and characterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. We demonstrate that growth responds interactively to global-change drivers, with species-specific sensitivities to the combined factors. Simultaneously high levels of precipitation and deposition benefited Fraxinus, but negatively affected Quercus' growth, highlighting species-specific interactive tree growth responses to combined drivers. For Fagus, a stronger growth response to higher temperatures was found when precipitation was also higher, illustrating the potential negative effects of drought stress under warming for this species. Furthermore, we show that past forest management can modulate the effects of changing temperatures on Quercus' growth; individuals in plots with a coppicing history showed stronger growth responses to higher temperatures. Overall, our findings highlight how tree growth can be interactively determined by global-change drivers, and how these growth responses might be modulated by past forest management. By showing future growth changes for scenarios of environmental change, we stress the importance of considering multiple drivers, including past management and their interactions, when predicting tree growth.


Assuntos
Mudança Climática , Fagus/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Quercus/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Secas , Europa (Continente) , Florestas , Ciclo do Nitrogênio , Temperatura Ambiente
2.
Ann Agric Environ Med ; 25(2): 285-291, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29936810

RESUMO

INTRODUCTION AND OBJECTIVE: The timings of Fraxinus and Betula flowering and pollen release overlap, which may cause increased allergic reactions in sensitive people. The aim of the present study was to characterize Fraxinus pollen seasons in Lublin (central-eastern Poland) and to identify meteorological factors that most determine the occurrence of airborne pollen of this taxon, as well as obtain forecast models for the basic characteristics of the pollen season. MATERIAL AND METHODS: The study was conducted in Lublin during the period 2001-2016, employing the volumetric method. The seasons were compared by PCA (Principal Component Analysis). To determine relationships between meteorological conditions and the pattern of pollen seasons, regression analysis was used. Data for the period 2001-2015 were used to create forecast models by applying regression analysis, while the 2016 data served to verify these models. RESULTS: Season end date and seasonal peak date were characterized by the lowest variation. The biggest differences were found for peak value and total annual pollen sum. The average dates of occurrence of ash pollen grains in the air of Lublin were between 13 April 13 - 3 May 3, whereas, on average, the pollen peak date occurred on 23 April. The factor loading values for the PC1 variable indicate that it is most strongly correlated with peak value and total pollen sum, while the PC2 variable correlated with the pollen season start date and season duration (a negative correlation). Regression models were developed for the following pollen season characteristics: season start, end and duration, seasonal peak date, and total annual pollen sum. CONCLUSIONS: The fit of the forecast models was at the level of 62-94%. Analysis of the data showed that weather conditions mainly in February were important factors controlling the Fraxinus pollen season.


Assuntos
Poluentes Atmosféricos/análise , Fraxinus/crescimento & desenvolvimento , Pólen/química , Poluentes Atmosféricos/imunologia , Poluição do Ar/análise , Fraxinus/química , Hipersensibilidade/epidemiologia , Conceitos Meteorológicos , Polônia/epidemiologia , Pólen/crescimento & desenvolvimento , Análise de Regressão , Estações do Ano , Tempo (Meteorologia)
3.
Environ Monit Assess ; 190(6): 355, 2018 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-29789963

RESUMO

The afforestation of arid lands faces many challenges, and perhaps the most important key for success is choosing one or more species that are adapted well for local environmental conditions. We explored species that would be suitable for the steppe region of Central Anatolia. Intensive site preparation included ripping the subsoil (to 80 cm) and plowing the upper soil before planting seedlings of Elaeagnus angustifolia, Robinia pseudoacacia, Fraxinus angustifolia, and Pinus nigra were used as tree species. We also tested the success of several shrub species: Amygdalus orientalis, Calligonum polygonoides, and Spartium junceum. After five growing seasons, E. angustifolia showed the highest survival, with 80% of planted seedlings remaining. For the shrubs, A. orientalis was the most successful species with a 95% survival rate. Broad-leaved trees grew a cumulative average of 34 cm in height in 5 years, whereas P. nigra seedings grew only 9 cm. The greatest height growth occurred in the shrubs, with A. orientalis gaining 40 cm in height in 5 years. Overall, E. angustifolia and A. orientalis appeared best suited for afforestation in these areas. R. pseodoacacia and F. angustifolia may also be used as alternative species.


Assuntos
Fraxinus/crescimento & desenvolvimento , Pinus/crescimento & desenvolvimento , Robinia/crescimento & desenvolvimento , Florestas , Plântula/crescimento & desenvolvimento , Solo , Árvores , Turquia
4.
J Econ Entomol ; 111(2): 732-740, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29474690

RESUMO

Emerald ash borer (EAB), Agrilus planipennis (Fairmaire; Coleoptera: Buprestidae), is decimating ash trees (Fraxinus spp.) in North America. Combatting EAB includes the use of insecticides; however, reported insecticide efficacy varies among published studies. This study assessed the effects of season of application, insecticide active ingredient, and insecticide application rate on green ash (Fraxinus pennsylvanica Marsh.) (Lamiales: Oleaceae) canopy decline caused by EAB over a 5- to 7-yr interval. Data suggested that spring treatments were generally more effective in reducing canopy decline than fall treatments, but this difference was not statistically significant. Lowest rates of decline (<5% over 5 yr) were observed in trees treated with imidacloprid injected annually in the soil during spring (at the higher of two tested application rates; 1.12 g/cm diameter at 1.3 m height) and emamectin benzoate injected biennially into the stem. All tested insecticides (dinotefuran, emamectin benzoate, and imidacloprid) under all tested conditions significantly reduced the rate of increase of dieback.


Assuntos
Besouros , Guanidinas , Controle de Insetos , Inseticidas , Ivermectina/análogos & derivados , Neonicotinoides , Nitrocompostos , Solo , Animais , Relação Dose-Resposta a Droga , Fraxinus/crescimento & desenvolvimento , Illinois , Estações do Ano
5.
Int J Biometeorol ; 62(6): 949-959, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29404687

RESUMO

It has been widely reported that the urban environment alters leaf and flowering phenophases; however, it remains unclear if land pavement is correlated with these alterations. In this paper, two popular deciduous urban trees in northern China, ash (Fraxinus chinensis) and maple (Acer truncatum), were planted in pervious and impervious pavements at three spacings (0.5 m × 0.5 m, 1.0 m × 1.0 m, and 2.0 m × 2.0 m apart). The beginning and end dates of the processes of leaf budburst and senescence were recorded in spring and fall of 2015, respectively. The results show that leaf budburst and senescence were significantly advanced in pavement compared to non-pavement lands. The date of full leaf budburst was earlier by 0.7-9.3 days for ash and by 0.3-2.3 days for maple under pavements than non-pavements, respectively. As tree spacing increases, the advanced days of leaf budburst became longer. Our results clearly indicate that alteration of leaf phenophases is attributed to land pavement, which should be taken into consideration in urban planning and urban plant management.


Assuntos
Acer/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Microclima , Folhas de Planta/crescimento & desenvolvimento , China , Planejamento de Cidades , Manufaturas , Estações do Ano , Temperatura Ambiente , Urbanização
6.
J Econ Entomol ; 110(3): 1096-1106, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28379445

RESUMO

Effective survey methods to detect and monitor recently established, low-density infestations of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), remain a high priority because they provide land managers and property owners with time to implement tactics to slow emerald ash borer population growth and the progression of ash mortality. We evaluated options for using girdled ash (Fraxinus spp.) trees for emerald ash borer detection and management in a low-density infestation in a forested area with abundant green ash (F. pennsylvanica). Across replicated 4-ha plots, we compared detection efficiency of 4 versus 16 evenly distributed girdled ash trees and between clusters of 3 versus 12 girdled trees. We also examined within-tree larval distribution in 208 girdled and nongirdled trees and assessed adult emerald ash borer emergence from detection trees felled 11 mo after girdling and left on site. Overall, current-year larvae were present in 85-97% of girdled trees and 57-72% of nongirdled trees, and larval density was 2-5 times greater on girdled than nongirdled trees. Low-density emerald ash borer infestations were readily detected with four girdled trees per 4-ha, and 3-tree clusters were as effective as 12-tree clusters. Larval densities were greatest 0.5 ± 0.4 m below the base of the canopy in girdled trees and 1.3 ± 0.7 m above the canopy base in nongirdled trees. Relatively few adult emerald ash borer emerged from trees felled 11 mo after girdling and left on site through the following summer, suggesting removal or destruction of girdled ash trees may be unnecessary. This could potentially reduce survey costs, particularly in forested areas with poor accessibility.


Assuntos
Besouros/fisiologia , Fraxinus/crescimento & desenvolvimento , Controle de Insetos , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Michigan , Densidade Demográfica , Árvores/crescimento & desenvolvimento
7.
PLoS One ; 12(2): e0171197, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28182638

RESUMO

The atmospheric carbon dioxide (CO2) level is expected to increase substantially, which may change the global climate and carbon dynamics in ecosystems. We examined the effects of an elevated atmospheric CO2 level on the growth of Quercus acutissima and Fraxinus rhynchophylla seedlings. We investigated changes in the chemical composition of leaf litter, as well as litter decomposition. Q. acutissima and F. rhynchophylla did not show differences in dry weight between ambient CO2 and enriched CO2 treatments, but they exhibited different patterns of carbon allocation, namely, lower shoot/root ratio (S/R) and decreased specific leaf area (SLA) under CO2-enriched conditions. The elevated CO2 concentration significantly reduced the nitrogen concentration in leaf litter while increasing lignin concentrations and carbon/nitrogen (C/N) and lignin/N ratios. The microbial biomass associated with decomposing Q. acutissima leaf litter was suppressed in CO2 enrichment chambers, while that of F. rhynchophylla was not. The leaf litter of Q. acutissima from the CO2-enriched chambers, in contrast with F. rhynchophylla, contained much lower nutrient concentrations than that of the litter in the ambient air chambers. Consequently, poorer litter quality suppressed decomposition.


Assuntos
Atmosfera/química , Dióxido de Carbono/farmacologia , Fraxinus , Folhas de Planta/efeitos dos fármacos , Quercus , Biomassa , Dióxido de Carbono/análise , Clima , Ecossistema , Fraxinus/efeitos dos fármacos , Fraxinus/crescimento & desenvolvimento , Fraxinus/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Quercus/efeitos dos fármacos , Quercus/crescimento & desenvolvimento , Quercus/metabolismo , Árvores/efeitos dos fármacos , Árvores/crescimento & desenvolvimento , Árvores/metabolismo
8.
Environ Entomol ; 46(2): 243-250, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28175243

RESUMO

Emerald ash borer (Agrilus planipennis Fairmaire) was recently found on a novel host in North America, white fringetree (Chionanthus virginicus L.) (Oleaceae). In this study, we artificially infested 4-yr-old, naïve white fringetree and white ash (Fraxinus americana L.) saplings under well-watered and water-deficit conditions with emerald ash borer eggs. We used physiological and phenotypical approaches to investigate both plant response to emerald ash borer and insect development at 21, 36, and 61 d postinfestation. Photosynthesis was reduced in both tree species by larval feeding, but not by water deficits. Emerald ash borer larvae established and survived successfully on white ash. Both establishment and survival were lower on white fringetree than on white ash. Larvae were larger, and had reached higher instars at all three time points on white ash than on white fringetrees. Larvae grew faster in white ash under water-deficit conditions; however, water-deficit conditions negatively impacted survival of larvae at 61 d postinfestation in white fringetrees, although head size did not differ among surviving larvae. White ash showed higher callus formation in well-watered trees, but no impact on larval survival was observed. In white fringetree, callus formation was not affected by water treatment, and was inversely related to larval survival. The higher rate of mortality and slow growth rate of larvae in white fringetree as compared to white ash suggest that populations of emerald ash borer may be sustained by white fringetree, but may grow more slowly than in white ash.


Assuntos
Besouros/fisiologia , Secas , Oleaceae/crescimento & desenvolvimento , Animais , Besouros/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Longevidade , Fotossíntese
9.
Sci Rep ; 6: 35303, 2016 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-27739483

RESUMO

Beyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time.


Assuntos
Ascomicetos/patogenicidade , Mudança Climática , Fraxinus/microbiologia , Doenças das Plantas/microbiologia , Fraxinus/crescimento & desenvolvimento
10.
Tree Physiol ; 36(11): 1310-1319, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27587483

RESUMO

Efficient leaf water supply is fundamental for assimilation processes and tree growth. Renovating the architecture of the xylem transport system requires an increasing carbon investment while growing taller, and any deficiency of carbon availability may result in increasing hydraulic constraints to water flow. Therefore, plants need to coordinate carbon assimilation and biomass allocation to guarantee an efficient and safe long-distance transport system. We tested the hypothesis that reduced branch elongation rates together with carbon-saving adjustments of xylem anatomy hydraulically compensate for the reduction in biomass allocation to xylem. We measured leaf biomass, hydraulic and anatomical properties of wood segments along the main axis of branches in 10 slow growing (SG) and 10 fast growing (FG) Fraxinus ornus L. trees. Branches of SG trees had five times slower branch elongation rate (7 vs 35 cm year-1), and produced a higher leaf biomass (P < 0.0001) and thinner xylem rings with fewer but larger vessels (P < 0.0001). On the contrary, we found no differences between SG and FG trees in terms of leaf-specific conductivity (P > 0.05) and xylem safety (Ψ50 ≈ -3.2 MPa). Slower elongation rate coupled with thinner annual rings and larger vessels allows the reduction of carbon costs associated with growth, while maintaining similar leaf-specific conductivity and xylem safety.


Assuntos
Fraxinus/fisiologia , Árvores/fisiologia , Xilema/fisiologia , Carbono/metabolismo , Fraxinus/crescimento & desenvolvimento , Transpiração Vegetal , Árvores/crescimento & desenvolvimento , Xilema/crescimento & desenvolvimento
11.
FEMS Microbiol Ecol ; 92(9)2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27364360

RESUMO

While Hymenoscyphus fraxineus causes dieback of the European ash (Fraxinus excelsior), flowering ash (F. ornus) appears resistant to the pathogen. To date, contributions of endophytic fungi to host resistance are unknown. The following hypotheses were tested: (i) endophytic fungi enhance the resistance of F. excelsior to the pathogen; (ii) resistance of F. ornus relies on its community of endophytic fungi. Two experiments were performed. (i) The effect of exudates of ash endophytes on the germination rate of H. fraxineus ascospores was studied in vitro Isolates of abundant Fraxinus leaf endophytes, such as Venturia fraxini, Paraconiothyrium sp., Boeremia exigua, Kretzschmaria deusta and Neofabraea alba inhibited ascospore germination. (ii) Ash seedlings inoculated in a climate chamber, with fungi sporulating on the previous year's leaf litter, were exposed to natural infections by the pathogen present in the forest. Non-inoculated seedlings were used as controls. Venturia spp. dominated the inoculated endophyte 'communities'. Subsequent exposure to H. fraxineus led to infection of F. excelsior leaves by the pathogen, but no differences in health status between pre-inoculated and non-inoculated seedlings were detected. Fraxinus ornus leaves experienced a low infection rate, independent of their colonization by endophytic fungi. These results did not support either hypothesis.


Assuntos
Ascomicetos/fisiologia , Endófitos/fisiologia , Fraxinus/microbiologia , Doenças das Plantas/microbiologia , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/isolamento & purificação , Endófitos/isolamento & purificação , Fraxinus/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle , Folhas de Planta/microbiologia
12.
Plant Physiol Biochem ; 99: 97-107, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26744995

RESUMO

Fraxinus mandshurica is considered a dioecious hardwood, and the temporal separation of the maturation of the male and female flowers is one reason that F. mandshurica has become an endangered species in China. Rainfall and low temperature influence pollen formation and dispersal and the blooming of female flowers. Therefore, low fertilization efficiency strongly influences the population of F. mandshurica. Nevertheless, few studies have investigated the sex-specific morphological, physiological and molecular differentiation of F. mandshurica during flowering and its responses to low temperature. In this study, we investigated the sexual differences in the morphological, physiological, and biochemical parameters of F. mandshurica during flowering and determined the physiological and biochemical parameters and expression levels of related genes in response to low-temperature stress induced by exposure to 4 °C (chilling stress) during pollen dispersal and fertilization. Our study supports the hypothesis that male flowers suffer more severe injuries while female flowers are more adaptable to environmental stress during flower development in F. mandshurica. The results showed higher physiological and biochemical levels of malondialdehyde, proline, and soluble sugar, as well as the expression of genes involved in calcium signaling, cold shock and DNA methylation in male flowers compared with female flowers, which suggested that male flowers suffer from more serious peroxidation than female flowers. In contrast, higher antioxidant capacity and FmaCAT expression were detected in female flowers, providing preliminary evidence that male flowers rapidly fade after pollination and further demonstrating that female flowers need a much stronger antioxidant enzyme system to maintain embryonic growth. Most peaks related to physiological and molecular responses were observed at 2-4 h and 8-10 h of exposure to chilling stress in the female and male flowers, respectively. This trend implies that female flowers have higher adaptability to low temperature during fertilization.


Assuntos
Temperatura Baixa , Flores/fisiologia , Fraxinus/fisiologia , Estresse Fisiológico/fisiologia , Flores/genética , Flores/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Estresse Fisiológico/genética
13.
Pest Manag Sci ; 72(5): 1023-30, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26194342

RESUMO

BACKGROUND: Economic and ecological impacts of ash (Fraxinus spp.) mortality resulting from emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion are severe in forested, residential and urban areas. Management options include girdling ash trees to attract ovipositing adult beetles and then destroying infested trees before larvae develop or protecting ash with a highly effective, systemic emamectin benzoate insecticide. Injecting this insecticide and then girdling injected trees a few weeks later could effectively create lethal trap trees, similar to a bait-and-kill tactic, if girdling does not interfere with insecticide translocation. We compared EAB larval densities on girdled trees, trees injected with the emamectin benzoate insecticide, trees injected with the insecticide and then girdled 18-21 days later and untreated controls at multiple sites. RESULTS: Pretreatment larval densities did not differ among treatments. Current-year larval densities were higher on girdled and control trees than on any trees treated with insecticide at all sites. Foliar residue analysis and adult EAB bioassays showed that girdling trees after insecticide injections did not reduce insecticide translocation. CONCLUSIONS: Girdling ash trees to attract adult EAB did not reduce efficacy of emamectin benzoate trunk injections applied ≥ 18 days earlier and could potentially be used in integrated management programs to slow EAB population growth.


Assuntos
Besouros , Fraxinus/química , Controle de Insetos/métodos , Inseticidas , Ivermectina/análogos & derivados , Árvores/química , Animais , Besouros/crescimento & desenvolvimento , Besouros/fisiologia , Fraxinus/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Árvores/crescimento & desenvolvimento
14.
Methods Mol Biol ; 1359: 537-50, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26619887

RESUMO

Since its development in the 1960s, plant cryopreservation is considered an extraordinary method of safe long-term conservation of biological material, as it does not induce genetic alterations and preserve the regeneration potential of the stored material. It is based on the storage of explants at cryogenic temperatures, such as the one of liquid nitrogen (-196 °C), where the metabolism within the cells is suspended; thus, the time for these cells is theoretically "stopped". Cryopreservation is particularly important for embryogenic cultures, as they require periodic subculturing for their maintenance, and this, in turn, increases the risk of losing the material, as well as its embryogenic potential. Periodic re-initiation of embryogenic cultures is possible; however, it is labor intensive, expensive, and particularly difficult when working with species for which embryogenic explants are available only during a limited period of the year. Among various methods of cryopreservation available for embryogenic cultures, slow cooling is still the most common approach, especially in callus cultures from softwood species. This chapter briefly reviews the cryopreservation of embryogenic cultures in conifers and broadleaf trees, and describes as well a complete protocol of embryogenic callus cryopreservation from common ash tree (Fraxinus excelsior L.) by slow cooling.


Assuntos
Criopreservação/métodos , Desenvolvimento Vegetal/genética , Técnicas de Embriogênese Somática de Plantas/métodos , Técnicas de Cultura de Tecidos/métodos , Fraxinus/genética , Fraxinus/crescimento & desenvolvimento , Nitrogênio/química , Sementes/genética , Sementes/crescimento & desenvolvimento , Traqueófitas/genética , Traqueófitas/crescimento & desenvolvimento , Madeira/genética , Madeira/crescimento & desenvolvimento
15.
Mikrobiol Z ; 77(5): 62-9, 2015.
Artigo em Ucraniano | MEDLINE | ID: mdl-26638486

RESUMO

The article summarizes our research results of pathogenic myco- and microflora, as well as harmful entomofauna on European Ash. It is shown that the most common and harmful diseaseis tuberculosis (its causal agent--bacteria Pseudomonas syringae pv.savastanoi (Smith 1908), which affects trunks, branches, twigs and buds of European Ash. It describes a number of pathogens and representatives mikofitozov malicious entomofauna that by virtue of its activities significantly weaken the growth, development and underestimate the qualitative characteristics of wood European Ash.


Assuntos
Entomophthorales/patogenicidade , Fraxinus/microbiologia , Doenças das Plantas/microbiologia , Pseudomonas syringae/patogenicidade , Entomophthorales/isolamento & purificação , Fraxinus/crescimento & desenvolvimento , Componentes Aéreos da Planta/crescimento & desenvolvimento , Componentes Aéreos da Planta/microbiologia , Pseudomonas syringae/isolamento & purificação , Ucrânia
16.
J Econ Entomol ; 108(5): 2344-53, 2015 10.
Artigo em Inglês | MEDLINE | ID: mdl-26453723

RESUMO

Protection of green ash trees (Fraxinus pennsylvanica Marshall) from the emerald ash borer (EAB), Agrilus planipennis Fairmaire, by soil applications of neonicotinoids (imidacloprid, clothianidin, and dinotefuran) was tested at five locations between 2005 and 2013. Application rate and spring versus fall application dates were evaluated in tests with neighborhood street trees and in one plantation of 65 ash trees. Insecticide treatments of ash trees at all five sites were initiated as the leading edge of the EAB invasion began to kill the first ash trees at each location. Trees were treated and evaluated at each site for 4 to 7 yr. Spring applications of imidacloprid were more efficacious than fall applications. Application rates of 0.8 g a.i./cm dbh or greater per year gave a higher level of protection and were more consistent than rates of 0.56 g a.i./cm dbh per year or less. The number of years between the first observation of canopy loss due to EAB and death of most of the control trees varied from three to seven years among test sites, depending on how many non-treated ash trees were nearby.


Assuntos
Besouros , Controle de Insetos , Inseticidas , Animais , Besouros/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Guanidinas , Imidazóis , Larva/crescimento & desenvolvimento , Neonicotinoides , Nitrocompostos , Ohio , Solo/química , Tiazóis
17.
Environ Manage ; 55(5): 1147-59, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25662933

RESUMO

Revegetation patterns after quarry abandonment have been widely studied from several ecological points of view, but a trait-based approach is still lacking. The aim of this study was to characterise the plant species assemblages and the associated functional traits filtered on different geomorphological surfaces in abandoned limestone quarry areas: artificial cliffs, embankments, and platforms. We then verified if species with certain traits were better able to overcome the dispersal and environmental filters necessary for establishment. To this aim, we analyzed 113 vegetation plots and collected data on 25 morphological, ecological, and dispersal traits to detect species adaptaions across these man-made environments. As a case study, we investigated the extraction basin of Botticino (Lombardy, Italy), the second largest in Italy. The results obtained by SIMPER and CCA analyses showed that rockiness, stoniness, slope, elevation, and time of surfaces are the main filters that varied across quarries and affected plant assemblages at the macro-scale level. Across the three geomorphological surfaces (meso-scale) of quarries, more specific abiotic filters selecting species were found. In turn, traits differentiation according to the three main geomorphological surfaces of quarry emphasized that further filters acting at the micro-scale imply differences in dispersal mechanisms and resource availability. This work highlighted the utility to study species assemblages and environmental filters to address quarry restoration according to the type of geomorphological surface. The investigation of some traits (chorological form, life forms, seed dispersal,s and plant height) can furnish some interesting indications for practice individuating further abiotic filters acting at the micro-scale.


Assuntos
Betulaceae/crescimento & desenvolvimento , Ecossistema , Recuperação e Remediação Ambiental , Fraxinus/crescimento & desenvolvimento , Quercus/crescimento & desenvolvimento , Biodiversidade , Itália , Sementes/crescimento & desenvolvimento , Especificidade da Espécie
18.
PLoS One ; 9(12): e114672, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25486253

RESUMO

Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of potassium, in Glomus sp. suggest that the well-known influence of tree species on chemical soil properties may be related to their mycorrhizal associates.


Assuntos
Fagus/metabolismo , Fraxinus/metabolismo , Minerais/análise , Micorrizas/fisiologia , Raízes de Plantas/metabolismo , Plantas/metabolismo , Biodiversidade , Ecossistema , Fagus/crescimento & desenvolvimento , Fagus/microbiologia , Florestas , Fraxinus/crescimento & desenvolvimento , Fraxinus/microbiologia , Microscopia Eletrônica de Varredura , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Plantas/microbiologia , Frações Subcelulares , Simbiose
19.
J Econ Entomol ; 107(3): 939-46, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25026651

RESUMO

Spathius galinae Belokobylskij & Strazanac is a recently described parasitoid of the emerald ash borer, Agrilus planipennis Fairmaire, in the Russian Far East, and is currently being considered for biocontrol introduction in the United States. Using A. planipennis larvae reared with freshly cut ash (Fraxinus spp.) sticks, we investigated the biology, life cycle, and rearing of S. galinae in the laboratory under normal rearing conditions (25 +/- 1 degrees C, 65 +/- 10% relative humidity, and a photoperiod of 16:8 [L:D] h). Our study showed that S. galinae took approximately 1 mo (29 d) to complete a single generation (from egg to adult) under the laboratory rearing conditions. After eclosion from eggs, larvae of S. galinae molted four times to reach the fifth instar, which then spun cocoons for pupation and development to adults. Adult female wasps had a median survival time of 7 wk with fecundity peaking 3 wk after emergence when reared in groups (of five females and five males) and 2 wk in single pairs. Throughout the life span, a single female S. galinae produced a mean (+/- SE) of 31 (+/- 3.0) progeny when reared in groups, and a mean (+/- SE) of 47 (+/- 5.3) progeny when reared in single pairs. Results from our study also showed that S. galinae could be effectively reared with A. planipennis larvae reared in both green (Fraxinus pennsylvanica Marshall) and tropical [Fraxinus uhdei (Wenzig) Lingelsh] ash sticks. However, the abortion (unemergence) rate of S. galinae progeny was much higher (20%) when reared with host larvae in green ash sticks than that (2.1%) in tropical ash sticks.


Assuntos
Agentes de Controle Biológico , Besouros/parasitologia , Vespas/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Feminino , Cadeia Alimentar , Fraxinus/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/parasitologia , Larva/fisiologia , Masculino , Pupa/crescimento & desenvolvimento , Pupa/parasitologia , Pupa/fisiologia , Vespas/crescimento & desenvolvimento
20.
Environ Entomol ; 43(3): 546-55, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24690169

RESUMO

Exotic herbivorous insects have drastically and irreversibly altered forest structure and composition of North American forests. For example, emerald ash borer (Agrilus planipennis Fairmaire) from Asia has caused wide-scale mortality of ash trees (Fraxinus spp.) in eastern United States and Canada. We studied the effects of forest changes resulting from emerald ash borer invasion on epigaeic or ground beetles (Coleoptera: Carabidae) along a gradient of ash dieback and gap sizes in southeastern Michigan. Ground beetles were sampled in hydric, mesic, and xeric habitats in which black (Fraxinus nigra Marshall), green (Fraxinus pennsylvanica Marshall), and white (Fraxinus americana L.) ash were the most common species, respectively. During 2006-2007, we trapped 2,545 adult ground beetles comprising 52 species. There was a negative correlation between percent ash tree mortality in 2006 and catches of all beetles. Catches of Agonum melanarium Dejean (in 2006) and Pterostichus mutus (Say) (in 2006-2007) were negatively correlated with tree mortality and gap size, respectively. However, catches of Pterostichus corvinus Dejean were positively correlated with gap size in 2006. As ash mortality and average gap size increased from 2006 to 2007, catches of all beetles as well as P. mutus and Pterostichus stygicus (Say) increased (1.3-3.9 times), while species diversity decreased, especially in mesic and xeric stands. Cluster analysis revealed that beetle assemblages in hydric and mesic stand diverged (25 and 40%, respectively) in their composition from 2006 to 2007, and that hydric stands had the most unique beetle assemblages. Overall, epigaeic beetle assemblages were altered in ash stands impacted by emerald ash borer; however, these impacts may dissipate as canopy gaps close.


Assuntos
Biota , Besouros/fisiologia , Florestas , Fraxinus/crescimento & desenvolvimento , Herbivoria , Animais , Espécies Introduzidas , Michigan , Estações do Ano
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