Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 698: 134129, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499344

RESUMO

Forest health status is negatively influenced by climate change, air pollution and other disturbances. Extreme droughts reduce stand productivity, increase vulnerability to pests, and can even provoke mortality. Growth dynamics at tree and forest stand levels are considered the main indicators of stability and productivity in forest ecosystem structures. The main climate drivers for tree growth were identified using basal area increment (BAI) as a synthetic indicator. BAI chronologies were obtained from increment cores for 1960-2012 period. Six species were analysed in an attempt to identify their growth limiting factors. For the most important oak species in Romania, resilience components were computed in order to analyse their response to drought events. Moreover, growth dynamics were analysed for two species in mixed and monoculture forests. The results suggest that - in comparison to Picea abies and Fagus sylvatica, the sensitivity of Quercus spp. is much higher (0.3-0.47). Oakspecies situated in the most drought-affected areas are sensitive to rainfall values from the previous autumn, current spring, and early summer, with April monthly values having the most significant effect on BAI increment (r = 0.47*) The most sensitive species to drought is Q. cerris and Q. frainetto. Their BAI reduction during drought is >50% compared with the BAI values before the drought period. The recovery capacity of tree growth following drought events is lower for Q. robur and Q. petraea and higher for Q. cerris and Q. frainetto. The mixed forest stands have not showed a constant higher resistance to drought.


Assuntos
Mudança Climática , Monitoramento Ambiental , Agricultura Florestal , Florestas , Árvores , Secas , Ecossistema , Fagus , Quercus , Romênia , Estações do Ano
2.
Sci Total Environ ; 698: 134074, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505359

RESUMO

This study aims to investigate the combined use of two types of remote sensing data - ALS derived and digital aerial photogrammetry data (based on imagery collected by airborne UAV sensors) - along with intensive field measurements for extracting and predicting tree and stand parameters in even-aged mixed forests. The study is located in South West Romania and analyzes data collected from mixed-species plots. The main tree species within each plot are Norway spruce (Picea abies L. Karst.) and Beech (Fagus sylvatica L.). The ALS data were used to extract the digital terrain model (DTM), digital surface model (DSM) and normalized canopy height model (CHM). Object-Based Image Analysis (OBIA) classification was performed to automatically detect and separate the main tree species. A local filtering algorithm with a canopy-height based variable window size was applied to identify the position, height and crown diameter of the main tree species within each plot. The filter was separately applied for each of the plots and for the areas covered with Norway spruce and beech trees, respectively (i.e. as resulted from OBIA classification). The dbh was predicted based on ALS data by statistical Monte Carlo simulations and a linear regression model that relates field dbh for each tree species with their corresponding ALS-derived tree height and crown diameter. The overall RMSE for each of the tree species within all the plots was 5.8 cm for the Norway spruce trees, respectively 5.9 cm for the beech trees. The results indicate a higher individual tree detection rate and subsequently a more precise estimation of dendrometric parameters for Norway spruce compared to beech trees located in spruce-beech even-aged mixed stands. Further investigations are required, particularly in the case of choosing the best method for individual tree detection of beech trees located in temperate even-aged mixed stands.


Assuntos
Monitoramento Ambiental , Tecnologia de Sensoriamento Remoto , Árvores , Fagus , Florestas , Lasers , Luz , Picea , Romênia
4.
Sci Total Environ ; 694: 133730, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31398641

RESUMO

Three gridded datasets containing interpolated daily and monthly precipitation and temperature values over the past five decades were tested against four tree-ring chronologies of oak (Quercus robur and Q. petraea). The objective of this research was to investigate the climate-growth relationship and whether the Pearson's product-moment correlation coefficients differ significantly if mean monthly precipitation and temperature data from the different climate databases, CRU, E-OBS and ROCADA are used. To this end, we selected two representative oak ecosystems in the South Carpathians, Romania, and analysed earlywood, latewood and tree-ring widths. Climate time series trends for the South Carpathians coldest, warmest days and wettest days were assessed with datasets from E-OBS and ROCADA, which differed in the density of their meteorological station network and their interpolation methods. The observed climatic parameters showed changes towards wetter conditions after the mid-1980s. For 1961-2013, E-OBS underestimated the mean daily temperature and daily precipitation compared with ROCADA. The results showed that higher extreme temperatures from January-March affected earlywood growth. In the investigated study region, latewood formation seemed to be affected by water availability mainly in May. Periods of drought associated with higher temperatures have limiting effects on tree growth, but these events are captured in different ways by each climate database analysed. Similarly, the results showed the discrepancy among datasets for earlywood and climate relationships. The results emphasize the importance of proper selection of climate data for assessing climate-tree growth relationships. For future dendroclimatological and dendroecological studies of oak in Romania, we recommend the ROCADA database, while E-OBS is recommended if an up-to-date climate dataset is needed.


Assuntos
Mudança Climática , Clima , Quercus , Secas , Ecossistema , Monitoramento Ambiental , Romênia , Temperatura Ambiente
5.
Sci Total Environ ; 694: 133709, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31394332

RESUMO

This study focuses on the climate growth drivers of Quercus robur L. (pedunculate oak) and Q. robur subsp. pedunculiflora K. Koch. (greyish oak), occurring in the biodiversity of three sites in southern Romania. We determined the degree of tolerance of the greyish oak, between the tardive and praecox varieties, to environmental stress, between 1951 and 2016. Total tree ring-width (RW), and earlywood (EW) and latewood (LW) measurements were subject of periodical and monthly climate-growth analysis. Our results revealed a moderate relationship between climate and tree-growth. A significant and positive relationship was observed between RW and previous growing season precipitation. Mean and minimum temperatures affected both positive and negative tree-rings during the growing season. We also observed that winter and spring represent key seasons for differentiating tardive from praecox varieties, affecting the intra-annual variability of ring-width, and EW and LW parameters. The correlation between the tree-ring measurements and daily climate data shows a clear offset of the starting growth between greyish oak varieties. A weak influence of stressors on tree-growth at the sites was observed through pointer year and resilience components analysis.


Assuntos
Monitoramento Ambiental/métodos , Quercus/crescimento & desenvolvimento , Clima , Romênia
6.
Sci Total Environ ; 689: 1104-1114, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31466150

RESUMO

Natural and anthropogenic disturbances pose a significant threat to forest condition. Continuous, reliable and accurate forest monitoring systems are needed to provide early warning of potential declines in forest condition. To address that need, state-of-the-art simulations models were used to evaluate the utility of C-, L- and P-band synthetic aperture radar (SAR) sensors within an integrated Earth-Observation monitoring system for beech, oak and coniferous forests in Romania. The electromagnetic simulations showed differentiated sensitivity to vegetation water content, leaf area index, and forest disturbance depending on SAR wavelength and forest structure. C-band data was largely influenced by foliage volume and therefore may be useful for monitoring defoliation. Changes in water content modulated the C-band signal by <1 dB which may be insufficient for a meaningful retrieval of drought effects on forest. C-band sensitivity to significant clear-cuts was rather low (1.5 dB). More subtle effects such as selective logging or thinning may not be easily detected using C- or L-band data with the longer P-band needed for retrieving small intensity forest disturbances. Overall, the simulations emphasize that additional effort is needed to overcome current limitations arising from the use of a single frequency, acquisition time and geometry by tapping the advantages of dense time series, and by combining acquisitions from active and passive sensors. The simulation results may be applicable to forests outside of Romania since the forests types used in the study have similar morphological characteristics to forests elsewhere in Europe.


Assuntos
Monitoramento Ambiental/métodos , Florestas , Radar , Romênia
7.
Sci Total Environ ; 691: 205-215, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31319256

RESUMO

Forest stands are often parameterized by vegetation indices such as the Leaf Area Index (LAI). However, other indices (i.e. stand denseness, espacement, canopy density, canopy cover, foliage cover, crown porosity, gap fraction) may better characterize forest structure. Terrestrial and airborne active sensor data has been used to describe canopy structural diversity and provide accurate estimates of forest structure indices. This study uses Terrestrial Laser Scanner (TLS) to characterize forest structure through the above-mentioned indices. The relationship between all of them was studied to assess the extent to which they relate and their capability to properly describe forest stands. A strong correlation was visible between LAI and the canopy density index (r = 0.87 to 0.91 depending on the extraction methods) despite the underevaluated values of the first. Even though more precise LAI estimates were expected from using co-registered multiple scans, the LAI variability proved to be low and correlations with the remaining indices weakened when compared to a single scan approach. An exception was canopy cover, a structural index that disregards the three-dimensionality of the canopy, with which the LAI obtained from multiple scans maintained a strong correlation. This suggests that multiple scanning leads to an unweighted oversampling of the scene, overshadowing its advantages in removing tree occlusions. Weak correlations were visible between classic forest structural indices (basal area density index, espacement index, denseness index) and the rest of the descriptors. Despite this exception, most of the forest indices showed average to strong correlations in-between each other. Therefore, we conclude that a better description of forest stands structure may be achieved through unsegmented single scan point cloud processing in both 3D and 2D space, optical data from the incorporated digital camera being a plus, but not an essential requirement.


Assuntos
Monitoramento Ambiental/métodos , Florestas , Lasers , Ecossistema , Luz , Tecnologia de Sensoriamento Remoto , Árvores
8.
Sci Total Environ ; 678: 721-727, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31078863

RESUMO

In the last years, large-scale mass forest withering and dieback have been reported for Scots pine (Pinus sylvestris) across eastern Europe, particularly in Romania. In these regions, the climate models forecast an increase in intensity and frequency of extreme climate events such as drought. Taking into account these aspects, the exact identification of the influences of drought on the loss of radial growth and vitality in Scots pine stands becomes mandatory. To achieve this aim, we developed the first country-wide Scots pine dendrochronological network in Romania consisting of 34 chronologies of basal area increment (BAI), and including 1401 individual tree-ring width series. Romanian Scots pine forests were severely impacted by the 2000 and 2012 droughts. The high temperatures and low precipitation from April to August were the main climatic causes of radial-growth reduction and large-scale withering in some areas. By mapping post-drought growth resilience, we identified locations where resilience was low and could identify foci of future forest dieback and high tree mortality. The projected appearance of similar prolonged and severe droughts in the future will lead to the damage or local extinction of some Scots pine forests in Romania, regardless of their age, composition or spatial location. The elaboration of adaptive forest management strategies to the impact of climate changes, specifically designed for the Scots pine stands, is not possible without knowing and understanding these aspects.


Assuntos
Mudança Climática , Secas , Florestas , Pinus sylvestris/crescimento & desenvolvimento , Romênia , Estações do Ano , Árvores/crescimento & desenvolvimento
9.
Sci Total Environ ; 656: 589-597, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529963

RESUMO

Plants are exposed to a broad range of environmental stresses, such as salinity and ozone (O3), and survive due to their ability to adjust their metabolism. The aim of this study was to evaluate the physiological and biochemical adjustments adopted by pomegranate (Punica granatum L. cv. Dente di cavallo) under realistic field conditions. One-year-old saplings were exposed to O3 [two levels denoted as ambient (AO) and elevated (EO) O3 concentrations] and salinity [S (salt, 50 mM NaCl)] for three consecutive months. No salt (NS) plants received distilled water. Despite the accumulation of Na+ and Cl- in the aboveground biomass, no evidence of visible injury due to salt (e.g. tip yellow-brown lesions) was found. The maintenance of leaf water status (i.e. unchanged values of electrolytic leakage and relative water content), the significant increase of abscisic acid, proline and starch content (+98, +65 and +59% compared to AO_NS) and stomatal closure (-24%) are suggested to act as adaptive mechanisms against salt stress in AO_S plants. By contrast, EO_NS plants were unable to protect cells against the negative impact of O3, as confirmed by the reduction of the CO2 assimilation rate (-21%), accumulation of reactive oxygen species (+10 and +225% of superoxide anion and hydrogen peroxide) and malondialdehyde by-product (about 2-fold higher than AO_NS). Plants tried to preserve themselves from further oxidative damage by adopting some biochemical adjustments [i.e. increase in proline content (+41%) and induction of catalase activity (8-fold higher than in AO_NS)]. The interaction of the two stressors induced responses considerably different to those observed when each stressor was applied independently. An analysis of the antioxidant pool revealed that the biochemical adjustments adopted by P. granatum under EO_S conditions (e.g. reduction of total ascorbate; increased activities of superoxide dismutase and catalase) were not sufficient to ameliorate the O3-induced oxidative stress.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Lythraceae/fisiologia , Ozônio/efeitos adversos , Estresse Salino/fisiologia , Adaptação Fisiológica , Estresse Fisiológico
10.
Environ Pollut ; 238: 812-822, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29627751

RESUMO

Assessing ozone (O3) risk to vegetation is crucial for informing policy making. Soil nitrogen (N) and phosphorus (P) availability could change stomatal conductance which is the main driver of O3 uptake into a leaf. In addition, the availability of N and P could influence photosynthesis and growth. We thus postulated that the sensitivity of plants to O3 may be changed by the levels of N and P in the soil. In this study, a sensitive poplar clone (Oxford) was subject to two N levels (N0, 0 kg N ha-1; N80, 80 kg N ha-1), three P levels (P0, 0 kg P ha-1; P40, 40 kg P ha-1; P80, 80 kg P ha-1) and three levels of O3 exposure (ambient concentration, AA; 1.5 × AA; 2.0 × AA) for a whole growing season in an O3 free air controlled exposure (FACE) facility. Flux-based (POD0 to 6) and exposure-based (W126 and AOT40) dose-response relationships were fitted and critical levels (CLs) were estimated for a 5% decrease of total annual biomass. It was found that N and P availability modified the dose-response relationships of biomass responses to O3. Overall, the N supply decreased the O3 CLs i.e. increased the sensitivity of poplar to O3. Phosphorus alleviated the O3-caused biomass loss and increased the CL. However, such mitigation effects of P were found only in low N and not in high N conditions. In each nutritional treatment, similar performance was found between flux-based and exposure-based indices. However, the flux-based approach was superior, as compared to exposure indices, to explain the biomass reduction when all nutritional treatments were pooled together. The best O3 metric for risk assessments was POD4, with 4.6 mmol m-2 POD4 as a suitable CL for Oxford poplars grown under various soil N and P conditions.


Assuntos
Poluentes Atmosféricos/análise , Ozônio/análise , Populus/fisiologia , Ar , Poluentes Atmosféricos/toxicidade , Biomassa , Alimentos , Nitrogênio/análise , Nitrogênio/metabolismo , Ozônio/toxicidade , Fósforo/análise , Fósforo/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/química , Populus/efeitos dos fármacos , Medição de Risco , Estações do Ano
12.
Sci Total Environ ; 599-600: 1493-1502, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28531958

RESUMO

The Balkan Peninsula is one of the largest and most important European glacial refugia. However, the evolutionary history and phylogeographic pattern of temperate tree species that survived in the Balkans glacial refugia and their contribution to the genetic structure of the current population in the Carpathian Mountains remains poorly understood. Using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP), and extensive population sampling, we explored the phylogeographic pattern of Carpinus betulus in both the Balkan Peninsula and the Carpathian region. We aimed to determine the locations of potential glacial refugia, in order to delineate post-glacial colonization routes, and also to test if northern cryptic refugia had persisted during the Last Glacial Maximum (LGM). Our results provide strong support for the existence of multiple refugia similar to the 'refugia-within-refugia' scenario, which would suggest that Carpinus betulus has experienced a complex evolutionary history. In agreement with pollen data, our findings corroborate with previous hypotheses suggesting that hornbeam has a distinct postglacial evolution in the southeast of Europe (Carpathians and Balkan Peninsula) compared with that in Western Europe. Three postglacial re-colonization routes, from three distinct effective glacial refugia: (1) the Dinaric Alps; (2) the Pirin and Rhodope Mountains and (3) the Strandzha Mountains, were detected within the Balkan Peninsula. The pattern of cpDNA haplotypes distribution across the Ukrainian Carpathians revealed a "suture zone", which is a consequence of contact due to postglacial re-colonization between hornbeam populations originating from all three effective glacial refugia. The peculiar haplotype geographical structure found in C. betulus and the identified multiple glacial refugia in the Balkans may have direct consequences in the management and conservation of hornbeam forest genetic resources.


Assuntos
Betulaceae/genética , DNA de Cloroplastos/genética , Evolução Molecular , Península Balcânica , DNA de Plantas/genética , Europa (Continente) , Variação Genética , Genética Populacional , Haplótipos , Filogenia , Filogeografia , Refúgio
13.
Sci Total Environ ; 596-597: 396-404, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28448915

RESUMO

Ground-level ozone (O3) affects trees through visible leaf injury, accelerating leaf senescence, declining foliar chlorophyll content, photosynthetic activity, growth, carbon sequestration, predisposing to pests attack and a variety of other physiological effects. Tree crown defoliation is one of the most important parameters that is representative of forest health and vitality. Effects of air pollution on forests have been investigated through manipulative experiments that are not representative of the real environmental conditions observed in the field. In this work we investigated the role of O3 concentration and other metrics (AOT40 and POD0) in affecting crown defoliation in temperate Romanian forests. The impacts of O3 were estimated in combination with nitrogen pollutants, climatic factors and orographic conditions, by applying a non-linear modelling approach (Random Forest and Generalised Regression Models). Ozone concentration and AOT40 under Romanian conditions were more important than meteorological parameters in affecting crown defoliation. In these particular conditions, POD0 never exceeded the critical level suggested by previous literature for forest protection, and thus was not important in affecting crown defoliation.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Folhas de Planta/efeitos dos fármacos , Árvores/efeitos dos fármacos , Poluição do Ar , Clima , Romênia
14.
Sci Total Environ ; 575: 1407-1414, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27717567

RESUMO

To artificially simulate the impacts of ground-level ozone (O3) on vegetation, ozone FACE (Free Air Controlled Exposure) systems are increasingly recommended. We describe here a new-generation, three-dimensional ozone FACE, with O3 diffusion through laser-generated micro-holes, pre-mixing of air and O3, O3 generator with integral oxygen generator, continuous (day/night) exposure and full replication. Based on three O3 levels and assumptions on the pre-industrial O3 levels, we describe principles to calculate relative yield/biomass and estimate impacts even at lower-than-ambient O3 levels. The case study is called FO3X, and is at present the only ozone FACE in Mediterranean climate and one of the very few ozone FACEs investigating more than one stressor at a time. The results presented here will give further impulse to the research on O3 impacts on vegetation all over the world.

15.
Environ Pollut ; 180: 299-303, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23807179

RESUMO

We examined the effect of ambient ozone on visible foliar injury, growth and biomass in field-grown poplar cuttings of an Oxford clone sensitive to ozone (Populus maximoviczii Henry × berolinensis Dippel) irrigated with ethylenediurea (EDU) or water for three years. EDU is used as an ozone protectant for plants. Protective effects of EDU on ozone visible injury were found. As a result, poplar trees grown under EDU treatment increased leaves, lateral branches and root density in the third year, although no significant enhancement of stem height and diameter was found. Ambient ozone (AOT40, 24.6 ppm h; diurnal hourly average, 40.3 ppb) may finally reduce carbon gain by reducing the number of branches, and thus sites for leaf formation, in ozone-sensitive poplar trees under not-limiting conditions.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Compostos de Fenilureia/farmacologia , Populus/fisiologia , Substâncias Protetoras/farmacologia , Irrigação Agrícola , Populus/efeitos dos fármacos
16.
J Environ Monit ; 14(6): 1710-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22531931

RESUMO

In the Romanian forest ecosystems, the first measurements of ambient ozone (O(3)) concentrations started in 1997 in 6 of 26 locations established in a trans-Carpathian Network. Furthermore, three additional ozone and other phytotoxic pollutant (NO(x), SO(2) and NH(3)) monitoring networks were installed in 2000 in Retezat (11 locations) and during 2006-2009 in Bucegi-Piatra Craiului (22 locations) LTER Sites. Since 2007, in four Intensive Forest Monitoring plots (level II), measurements of ozone concentrations were developed. Measurements were made using the Ogawa® passive sampler system during the growing season (April to October). In the Bucegi LTER Site, the seasonal means of 42.5-47.2 ppb in 2006 and 2008 were higher than those determined in the Carpathian Network in the 1997-1999 period (39.0-42.0 ppb), while the 2009 mean of 40.0 ppb was in the range of these values. The O(3) levels were slightly higher than those measured in Retezat LTER Site. In the Intensive Forest Monitoring Network (level II), no significant differences in ozone concentrations between individual core plots were noticed. The seasonal means for each plot range between 36.8 and 49.8 ppb in 2008. An influence of ozone concentrations on crown condition and tree volume growth was not determined.


Assuntos
Poluentes Atmosféricos/análise , Ozônio/análise , Árvores , Poluição do Ar/estatística & dados numéricos , Amônia/análise , Ecossistema , Monitoramento Ambiental , Óxidos de Nitrogênio/análise , Romênia , Estações do Ano , Dióxido de Enxofre/análise
17.
Environ Monit Assess ; 184(12): 7491-515, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22234644

RESUMO

Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006-2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O(3)) was high indicating a potential for phytotoxicity. Ammonia (NH(3)) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH < 5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type's structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised.


Assuntos
Poluição do Ar/análise , Ecossistema , Monitoramento Ambiental , Árvores/crescimento & desenvolvimento , Chuva Ácida/análise , Poluição do Ar/estatística & dados numéricos , Biodiversidade , Ecologia , Nitrogênio/análise , Ozônio/análise , Fósforo/análise , Romênia , Árvores/classificação
18.
Environ Pollut ; 137(3): 546-67, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16005766

RESUMO

In the Retezat Mountains concentrations of O3, NO2 and SO2 in summer season 2000-2002 were low and below toxicity levels for forest trees. While NH3 concentrations were low in 2000, the 2001 and 2002 concentrations were elevated indicating possibility for increased N deposition to forest stands. More than 90% of the rain events were acidic with pH values <5.5, contributing to increased acidity of soils. Crown condition of Norway spruce (Picea abies) and European beech (Fagus sylvatica) was good, however, defoliation described as >25% of foliage injured increased from 9.1% in 2000 to 16.1% in 2002. Drought that occurred in the southern Carpathians between fall 2000 and summer 2002 and frequent acidic rainfalls could cause the observed decline of forest condition. Both Norway spruce and European beech with higher defoliation had lower annual radial increments compared to the trees with low defoliation. Ambient O3 levels found in the Retezat did not affect crown condition of Norway spruce or European beech.


Assuntos
Poluição do Ar , Ecossistema , Árvores/crescimento & desenvolvimento , Chuva Ácida , Monitoramento Ambiental/métodos , Concentração de Íons de Hidrogênio , Romênia , Solo/análise
19.
Environ Pollut ; 130(1): 17-32, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15046837

RESUMO

Within the framework of the project "Effects of forest health on biodiversity with emphasis on air pollution in the Carpathian Mountains" 26 permanent study sites were established in the vicinity of the ozone monitoring sites. The study sites were located on the NW-SE transect through the Western (12 sites), Eastern (11 sites) and Southern (3 sites) Carpathians in forest ecosystems typical of each area. Some of the forest monitoring sites were located in national parks, biosphere reserves and areas of protected landscape. Each permanent site of 0.7 ha area consisted of 5 small 500m(2) circular plots, arranged in the form of a cross, i.e. four placed on the cardinal points (N, E, S, W) and one in the center. Phytosociological records were done twice during the 1998 growing season using the Braun-Blanquet's method. The study sites represented various types of forest: Picea abies stands (8), beech (Fagus sylvatica) stands (10), fir (Abies alba) stands (2) and mixed beech-fir, spruce-fir and beech-spruce stands (6). Age of most stands was 80-100 years. Degree of crown damage varied greatly between sites, a percentage of damaged trees decrease in Carpathians from West to East. It corresponds well with the O(3) level in these areas. Typical damage by O(3) in herb layer species in several Carpathian sites were found. Land-use map for the entire Carpathian Mountains and two detailed land use maps for Tatras (Western Carpathians) and Retezat (Southern Carpathians) are presented. A little more than half of the Carpathian territory is forested. The most densely forested are Eastern Carpathians, while the most sparsely Western Carpathians. Arable lands occupy 22.6% of the Carpathians, pastures and meadows 6.2%, water bodies 1.9%, and build up areas several percent. In the highest elevation of the Carpathians alpine meadows (11.3%) and rocks (3.5%) are distributed.


Assuntos
Monitoramento Ambiental/métodos , Árvores/química , Agricultura , Poluição do Ar , Altitude , Biodiversidade , Europa Oriental , Geografia , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Árvores/classificação , Árvores/efeitos dos fármacos , Reforma Urbana
20.
Environ Pollut ; 130(1): 41-54, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15046839

RESUMO

Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Malá Fatra, Morské Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species.


Assuntos
Abies/química , Elementos , Fagus/química , Picea/química , Abies/ultraestrutura , Poluição do Ar , Ecossistema , Exposição Ambiental , Europa Oriental , Fagus/ultraestrutura , Metais/análise , Microscopia Eletrônica de Varredura/métodos , Picea/ultraestrutura , Folhas de Planta/química , Folhas de Planta/ultraestrutura , Dióxido de Enxofre/toxicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA