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1.
Phytochemistry ; 167: 112084, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31415913

RESUMO

The medicinal plant drug "Tiliae flos" consists of the botanical flowers and bracts of Tilia sp., gathered almost exclusively during flowering. In this study, we examined the changes in the metabolome of specialized products in the bracts of Tilia platyphyllos from the appearance of the organ till the onset of senescence by LC-ESI-MS and data mining. A set of 504 natural products were detected, 241 of which showed significant seasonal variation (p < 9.92E-5). Seven compounds were quantified and an additional 45 were putatively identified. These included flavonoid glycosides, catechins, procyanidins, quinic acid derivatives (including chlorogenic acid) and coumarins. Compared to bracts during flowering, young tissues were characterized by a relatively high diversity of polyphenolic substances. Higher amounts of flavonol glycosides (quercetin, kaempferol), catechins and derivatives have been observed. Deoxyhexosides were almost exclusive to this phenological stage. Changes of about one order of magnitude were not uncommon. For some substances, 5-fold differences were observed (calibration with authentic standards). Some compounds (e.g. the coumarin fraxin) were more prominent at the late fruit growth stage. It was shown that bracts gathered before or after flowering could potentially be therapeutically useful. Changes are rapid during the early phase of bract development: three different groups of compounds presented their maxima during the first 32 days. Considering seasonal variation is of extreme importance during bioactivity tests and screening candidate sources for bioactive natural products. In the case of T. platyphyllos, young and old bracts can be of interest because of their high diversity of distinct specialized metabolites.


Assuntos
Metabolômica , Tilia/crescimento & desenvolvimento , Tilia/metabolismo , Produtos Biológicos/metabolismo , Estações do Ano
2.
Chemosphere ; 229: 589-601, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31100630

RESUMO

The study aimed to evaluate the physiological mechanisms underlying differences in metals and metalloid uptake and tolerance of two tree species cultivated in mining waste material. Two-year old Acer platanoides L. and Tilia cordata Mill. were cultivated in mining sludge characterized by high pH, salinity and an extremely high concentration of As. Both species were able to develop leaves from leafless seedlings, however, their total biomass was greatly reduced in comparison to control plants, following the severe disturbances in chlorophyll content. Phytoextraction abilities were observed for T. cordata for Ba, Nb, Rb and Se, and phytostabilisation was stated for Pd, Ru, Sc and Sm for both species, Ba and Nd for A. platonoides and Be for T. cordata only. Metal exclusion was observed for the majority of detected elements indicating an intense limitation of metal transport to photosynthetic tissue. A diversified uptake of elements was accompanied by a species-specific pattern of physiological reaction during the cultivation in sludge. Organic ligands (glutatnione and low-molecular-weight organic acids) were suppressed in A. platanoides, and enhanced biosynthesis of phenolic compounds was observed for both species, being more pronounced in T. cordata. Despite its higher accumulation of key metabolites for plant reaction to oxidative stress, such as phenolic acids, flavonoids and organic ligands, T. cordata exhibited relatively lower tolerance to sludge, probably due to the increased uptake and translocation rate of toxic metal/loids to aerial organs and/or restricted accumulation of salicylic acid which is known to play a decisive role in mechanisms of plant tolerance.


Assuntos
Acer/crescimento & desenvolvimento , Mineração , Poluentes do Solo/farmacocinética , Tilia/crescimento & desenvolvimento , Acer/efeitos dos fármacos , Arsênico/análise , Arsênico/farmacocinética , Biodegradação Ambiental , Clorofila/metabolismo , Metais/farmacocinética , Metais/toxicidade , Fotossíntese/efeitos dos fármacos , Fotossíntese/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Especificidade da Espécie , Tilia/efeitos dos fármacos , Árvores/efeitos dos fármacos , Árvores/crescimento & desenvolvimento
3.
Int J Biometeorol ; 62(5): 795-808, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29218447

RESUMO

Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees (Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of increment cores, we are able to trace back their growth for the last 50 to 100 years. A general growth trend can be shown by comparing recent basal area growth with estimates from extrapolating a growth function that had been fitted with growth data from earlier years. Estimating a linear model, we show that air temperature and precipitation significantly influence tree growth within the last 20 years. Under consideration of housing density, the results reveal that higher air temperature and less precipitation led to higher growth rates in high-dense areas, but not in low-dense areas. In addition, our data reveal a significantly higher variance of the ring width index in areas with medium housing density compared to low housing density, but no temporal trend. Transferring the results to forest stands, climate change is expected to lead to higher tree growth rates.


Assuntos
Clima , Tilia/crescimento & desenvolvimento , Berlim , Habitação , Modelos Lineares , Chuva , Temperatura Ambiente , Árvores/crescimento & desenvolvimento
4.
Int J Biometeorol ; 61(6): 1095-1107, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27987049

RESUMO

The effects of urban conditions on tree growth have been investigated in an increasing number of studies over the last decades, emphasizing the harsh environment of cities. Urban trees often grow in highly paved, compacted sites with consequently less soil moisture, higher soil temperatures, and greater vapor pressure deficits. However, there is still a knowledge gap regarding the impact of harsh paved environments on urban tree growth during drought years on the growth patterns of urban trees. The present study investigated the structure and growth of the common urban tree species small-leaved lime (Tilia cordata) at a highly paved public square (CPS) compared with a contrasting more open, greener square (OGS). Continuously, measured high precision dendrometer data along with meteorological data of the extreme dry and warm summer 2015 as well as dendrochronological data of the sampled trees were investigated to analyze tree growth during a drought year. The results highlight different tree dimensions and growth patterns of the trees at both sites, influenced by tree age and distinct site conditions. While the trees at OGS grew up to 2.5 mm from July until mid of August, the trees at CPS had only 0.4-mm diameter increment. After the initial expansion at CPS, tree diameter contracted again during summer to the point of shrinkage (up to 0.8 mm) at the end of our investigation. Further drought year analysis confirmed the patterns of significant stem growth reductions in the consecutive two years following the drought. A correlation analysis revealed that transpiration, air temperature, and vapor pressure deficit were negatively correlated with the daily diameter growth, whereas precipitation had a strong positive effect. Due to high transpiration rates associated with anisohydric water use behavior, T. cordata was able to provide evaporative cooling even during drought. However, this anisohydric behavior resulted in substantial growth decline afterwards especially at paved sites like CPS. Our results suggest selection of tree species, such as those with isohydric water use behavior, which may achieve a better balance between growth, transpiration, and hence evaporative cooling.


Assuntos
Microclima , Tilia/crescimento & desenvolvimento , Cidades , Alemanha , Folhas de Planta , Tempo (Meteorologia)
5.
Am J Bot ; 103(9): 1687-93, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27630119

RESUMO

PREMISE OF THE STUDY: Sprouting in woody plant species allows for the long-term persistence of small, isolated populations experiencing changing environments and can preserve genetic diversity in these populations despite the infrequent recruitment of sexually produced individuals. We examined demographic data collected over a 10-yr period for Tilia americana var. caroliniana populations in the context of genetic structure as an empirical case study of this concept. METHODS: Two back-barrier islands on the Georgia coast of the United States were completely censused for Tilia americana var. caroliniana. Recruitment, growth, and mortality of all stems were tracked over 10 yr. All genets were genotyped using eight nuclear microsatellite loci to assess population genetic structure among sampled stems and among populations in the region. KEY RESULTS: The two island populations differed in their ability to establish seedlings despite having similar patterns in flowering frequency. Seedling mortality was high throughout the 10 yr, and cycling of ramets within genets was common. Long-term recruitment in this system appears to be primarily a result of vegetative growth via basal sprouts. Genetic structure was limited, both between islands and among populations in the region. CONCLUSIONS: Long-lived woody species that persist by vegetative reproduction may unexpectedly influence regional forest responses to climate change, particularly on the trailing edge of a species' distribution.


Assuntos
Variação Genética , Tilia/fisiologia , Mudança Climática , Genótipo , Georgia , Ilhas , Repetições de Microssatélites , Dinâmica Populacional , Estações do Ano , Tilia/genética , Tilia/crescimento & desenvolvimento
6.
Ying Yong Sheng Tai Xue Bao ; 24(3): 614-20, 2013 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-23755471

RESUMO

1 m x 1 m fixed quadrats were parallelly arranged with a space of 2 m in each of six forest gaps in Pinus koraiensis-dominated broadleaved mixed forest, taking the gap center as the starting point and along east-west and south-north directions. In each quadrat, the coverage and abundance of herbaceous plants at different height levels were investigated by estimation method in June and September 2011, and the matrix characteristics within the quadrats were recorded. Canopy analyzer was used to take fish-eye photos in the selected overcast days in each month from June to September, 2011, and the relative light intensity was calculated by using Gap Light Analyzer 2.0 software. The differences in the relative light intensity and herbaceous plants coverage and richness between different gaps as well as the correlations between the coverage of each species and the direct light, diffuse light, and matrix were analyzed. The results showed that in opening areas and under canopy, the relative light intensity in large gaps was higher than that in small gaps, and the variation ranges of diffuse light and direct light from gap center to gap edge were bigger in large gaps than in small gaps. The direct light reaching at the ground both in large gaps and in small gaps was higher in the north than in the south direction. In the Z1, Z2, Z3, and Z4 zones, both the coverage and the richness of herbaceous plants were larger in large gaps than in small gaps, and the differences of species richness between large and small gaps reached significant level. The coverage of the majority of the herbaceous plants had significant correlations with diffuse light and matrix, and only the coverage of a few herbaceous plants was correlated with direct light.


Assuntos
Ecossistema , Pinus/crescimento & desenvolvimento , Luz Solar , Árvores/crescimento & desenvolvimento , Betula/crescimento & desenvolvimento , China , Conservação dos Recursos Naturais , Eleutherococcus/crescimento & desenvolvimento , Tilia/crescimento & desenvolvimento
7.
Ying Yong Sheng Tai Xue Bao ; 24(11): 3043-9, 2013 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-24564130

RESUMO

Taking the Korean pine broadleaved forest in Liangshui Nature Reserve of Heilongjiang Province, Northeast China as test object, this paper studied the species composition and diameter class structure, and by using point pattern analysis, analyzed the spatial distribution pattern and spatial association of the main populations. In the Reserve, there were a total of 16 species with diameter greater than 1 cm in tree layer, and great differences were observed in the densities of main populations. Coniferous trees such as Pinus koraiensis and Abies nephrolepis were dominant. The diameter class structure of the populations presented as an inverse "J" curve, indicating a good regeneration across the community. The main populations were mostly in aggregated distribution pattern, except that the P. koraiensis populations at the scales of 19-21 m and 44 m as well as the Acer tegmentosum populations close to the largest research scale were in random distribution. The P. koraiensis populations at all research scales were approximately in random distribution, and had the minimum aggregation. A. nephrolepis, Tilia amurensis, and A. tegmentosum populations all presented a random distribution trend. Except that the P. koraiensis and A. nephrolepis at 2-3 m scale and the A. nephrolepis and A. tegmentosum populations at 37-81 m scale had significant positive association, no significant associations were observed between other populations. All the tree species presented an overall non-significant positive association.


Assuntos
Conservação dos Recursos Naturais , Florestas , Pinus/crescimento & desenvolvimento , Árvores/classificação , Abies/crescimento & desenvolvimento , China , Pinus/anatomia & histologia , Dinâmica Populacional , Análise Espacial , Tilia/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento
8.
Tree Physiol ; 32(8): 1021-32, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22659458

RESUMO

Tree ring analysis investigates growth processes at time horizons of several weeks to millennia, but lacks the detail of short-term fluctuation in cambial activity. This study used electronic high-precision dendrometry for analyzing the environmental factors controlling stem diameter variation and radial growth in daily resolution in five co-existing temperate broad-leaved tree species (genera Fraxinus, Acer, Carpinus, Tilia and Fagus) with different growth and survival strategies. Daily stem radius change (SRC(d)) was primarily influenced by the atmospheric demand for water vapor (expressed either as vapor pressure deficit (D) or relative air humidity (RH)) while rainfall, soil matrix potential, temperature and radiation were only secondary factors. SRC(d) increased linearly with increasing RH and decreasing D in all species. The positive effect of a low atmospheric water vapor demand on SRC(d) was largest in June during the period of maximal radial growth rate and persisted when observation windows of 7 or 21 days instead of 1 day were used. We found a high synchronicity in the day-to-day growth rate fluctuation among the species with increment peaks corresponding to air humidity maxima, even though the mean daily radial growth rate differed fivefold among the species. The five -species also differed in the positive slope of the growth/RH relationship with the steepest increase found in Fraxinus and the lowest in Fagus. We explain the strong positive effect of high RH and low D on radial stem increment by lowered transpiration which reduces negative pressure in the conducting system and increases turgor in the stem cambium cells, thereby favoring cell division and expansion. The results suggest that mechanistic models of tree growth need to consider the atmospheric water status in addition to the known controlling environmental factors: temperature, soil moisture and precipitation. The results further have implications for sensitivity analyses of tree growth to climatic changes.


Assuntos
Clima , Umidade , Magnoliopsida/crescimento & desenvolvimento , Folhas de Planta , Caules de Planta/crescimento & desenvolvimento , Transpiração Vegetal , Vapor , Árvores/crescimento & desenvolvimento , Acer/crescimento & desenvolvimento , Betulaceae/crescimento & desenvolvimento , Divisão Celular , Fagus/crescimento & desenvolvimento , Fraxinus/crescimento & desenvolvimento , Luz , Magnoliopsida/fisiologia , Chuva , Estações do Ano , Solo , Temperatura Ambiente , Tilia/crescimento & desenvolvimento , Árvores/fisiologia
9.
Mycorrhiza ; 21(8): 703-719, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21472449

RESUMO

The aim of this work was to evaluate the effects of selected mycorrhiza obtained in the urban environment on growth, leaf gas exchange, and drought tolerance of containerized plants growing in the nursery. Two-year-old uniform Acer campestre L., Tilia cordata Mill., and Quercus robur L. were inoculated with a mixture of infected roots and mycelium of selected arbuscular (maple, linden) and/or ectomycorrhiza (linden, oak) fungi and grown in well-watered or water shortage conditions. Plant biomass and leaf area were measured 1 and 2 years after inoculation. Leaf gas exchange, chlorophyll fluorescence, and water relations were measured during the first and second growing seasons after inoculation. Our data suggest that the mycelium-based inoculum used in this experiment was able to colonize the roots of the tree species growing in the nursery. Plant biomass was affected by water shortage, but not by inoculation. Leaf area was affected by water regime and, in oak and linden, by inoculation. Leaf gas exchange was affected by inoculation and water stress. V(cmax) and J(max) were increased by inoculation and decreased by water shortage in all species. F(v)/F(m) was also generally higher in inoculated plants than in control. Changes in PSII photochemistry and photosynthesis may be related to the capacity of inoculated plants to maintain less negative leaf water potential under drought conditions. The overall data suggest that inoculated plants were better able to maintain physiological activity during water stress in comparison to non-inoculated plants.


Assuntos
Inoculantes Agrícolas/crescimento & desenvolvimento , Agricultura Florestal/métodos , Fungos/crescimento & desenvolvimento , Micorrizas/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Água/metabolismo , Acer/crescimento & desenvolvimento , Acer/metabolismo , Clorofila/metabolismo , Planejamento de Cidades , Fotossíntese , Quercus/crescimento & desenvolvimento , Quercus/metabolismo , Tilia/crescimento & desenvolvimento , Tilia/metabolismo , Árvores/metabolismo
10.
Ying Yong Sheng Tai Xue Bao ; 21(7): 1627-34, 2010 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-20879516

RESUMO

Geostatistic methods were applied to study the spatial heterogeneity of top soil (0 - 10 cm) ammonium N and nitrate N in a broadleaved-Korean pine mixed forest of Changbai Mountains, Northeast China. The semi-variogram of soil ammonium N and nitrate N could be well fitted by spherical or Gaussian model. The spatial distribution of soil ammonium N and nitrate N all exhibited moderate autocorrelation, with the structural ratio being 0.70% - 41.47% and 32.26% - 52.66%, and the autocorrelation degree of soil ammonium N was smaller than that of soil nitrate N, with the variation distance being 8.87 and 9.76 m, respectively. Spatially, soil ammonium N and nitrate N were distributed in patches, and the spatial heterogeneity of soil ammonium N was higher than that of soil nitrate N. There was a significant negative correlation between soil nitrate N and soil moisture content, while soil ammonium N had less correlation with soil moisture.


Assuntos
Ecossistema , Nitrogênio/análise , Pinus/crescimento & desenvolvimento , Solo/análise , China , Nitratos/análise , Nitratos/química , Compostos de Amônio Quaternário/análise , Compostos de Amônio Quaternário/química , Tilia/crescimento & desenvolvimento
11.
Ying Yong Sheng Tai Xue Bao ; 21(9): 2171-8, 2010 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-21265134

RESUMO

In order to understand the composition and spatiotemporal dynamics of the litter falls at community level in a broad-leaved Korean pine mixed forest in Changbai Mountains, litter falls were collected from 150 containers in a 25 hm2 permanent plot in 2008. The leaf litters in the containers were from 35 tree species, accounting for 67.3% of the total number (52) of the tree species with DBH > or =1 cm in the plot. The litter falls had a weight 29.39 kg, equivalent to 3918.4 kg x hm(-2) among which, broad leaves, miscellany, needle leaves, and branches occupied 61.7%, 18.0%, 11.7%, and 8.6%, respectively. About 83.8% of the broad leaves were from Tilia amurensis, Fraxinus mandshurica, Quercus mongolica, Acer mono, and Ulmus japonica. The litter falls showed an evident seasonal dynamics, with the peaks occurred from 13 September to 10 October, e.g., the litter falls from T. amurensis and Pinus koraiensis peaked in 13-26 September, while those from Q. mongolica, U. japonica, and A. pseudo-sieboldianum peaked in 27 September to 10 October. There was a great difference in the mass of the litter falls among the containers, e.g., with 150-200 g litters in 68 containers and >500 g litters in 1 container. The species number of the litter falls in a container was 18 in maximum, and was 12 in common (32 containers). Litter falls mass was positively proportional to the sum of the basal area at breast height of parent trees in the plot, and the amount of the litter falls in the containers was related with the locations of the containers, exhibiting an evident spatial heterogeneity in the plot.


Assuntos
Pinus/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , China , Fraxinus/crescimento & desenvolvimento , Dinâmica Populacional , Quercus/crescimento & desenvolvimento , Estações do Ano , Especificidade da Espécie , Tilia/crescimento & desenvolvimento
12.
Ying Yong Sheng Tai Xue Bao ; 21(9): 2179-86, 2010 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-21265135

RESUMO

Taking a Korean pine (Pinus koraiensis) forest stand 37 years after selective cutting as test object, this paper studied the effects of selective cutting on the intra- and interspecies competitions among the major tree species in the stand. Selective cutting had significant effects on the population structure, distribution pattern, and competition index of the major species. There was a significant negative correlation between the changes of competition index and tolerance index of the tree species (r = -0.8821). The intra-species competition index had significant linear relationships with the aggregation index and the number of individuals. Heliophilous species Betula costata and Tilia amurensis had the largest aggregation index, and their intra-species competitions were stronger than interspecies competitions, being favorable to the coexistence of different species. Selective cutting weakened the competition of P. koraiensis with its companion tree species, while strengthened the competition of heliophilous species with other tree species. After 37 years of selective cutting, P. koraiensis varied little in its competition stress, being helpful to its regular growth. Because of self-thinning, the dominance of B. costata and T. amurensis had somewhat decrease. The competition stress suffered by Abies nephrolepis was weakened, being beneficial to its regeneration.


Assuntos
Betula/crescimento & desenvolvimento , Ecossistema , Pinus/crescimento & desenvolvimento , China , Conservação dos Recursos Naturais , Tilia/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento
13.
Ying Yong Sheng Tai Xue Bao ; 21(9): 2209-16, 2010 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-21265139

RESUMO

Taking the mixed leaf litters in broadleaved-Korean pine forests at different succession stages (secondary birch forest, selective cutting forest, and original mixed forest) and the leaf litters of the dominant tree species (Betula costata, Tilia amurensis, and Pinus koraiensis) in these forests in Xiaoxing' an Mountains, China as test objects, this paper studied their remaining rates and nutrient dynamics in October 2006-November 2008 by using decomposition bag method. For all test leaf litters, their remaining rate had an exponential relationship with time. The annual decomposition constant (k) ranged from 0.137 to 0.328, and the time for decomposing 50% (t50%) and 95% (t95%) was 2.340-4.989 years and 9.360-21.796 years, respectively. No significant differences were observed in the decomposition rates of the leaf litters among the forests, but the k value of the mixed leaf litters was decreased in the order of original mixed forest > selective cutting forest > secondary birch forest, while that of the dominant tree species leaf litters had no obvious pattern. During decomposition, the elements C, P, and K in leaf litters released continuously, and the release pattern of C followed linear function, while that of P and K followed a function of higher degree. Element N presented different levels of accumulation, but had no clear pattern.


Assuntos
Carbono/metabolismo , Ecossistema , Fósforo/metabolismo , Pinus/metabolismo , Folhas de Planta/metabolismo , China , Pinus/crescimento & desenvolvimento , Potássio/metabolismo , Tilia/crescimento & desenvolvimento , Tilia/metabolismo
14.
Am Nat ; 173(1): 105-12, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19012491

RESUMO

Periodical cicadas (Magicicada spp.) are insect herbivores that feed on host tree roots, but their distribution among hosts is determined largely by the oviposition of female cicadas in the previous generation. A pattern of decreasing tree growth rates with increasing cicada densities is predicted when considering the costs of chronic root herbivory, but the opposite pattern is expected when considering adaptive habitat selection. Here, we report observations indicating that the relationship between periodical cicada densities and host tree growth rates is hump shaped. We suggest that both herbivory and habitat selection are likely to be key processes explaining this pattern, resulting in regions of positive and negative correlation. These results suggest that the effects of cicada herbivory are most apparent at relatively high cicada densities, while habitat selection tends to distribute cicada herbivory on host trees that are able to compensate for cicada root herbivory up to threshold cicada densities.


Assuntos
Ecossistema , Hemípteros/fisiologia , Árvores/crescimento & desenvolvimento , Acer/crescimento & desenvolvimento , Análise de Variância , Animais , Liriodendron/crescimento & desenvolvimento , Oviposição , Raízes de Plantas , Dinâmica Populacional , Tilia/crescimento & desenvolvimento
15.
Ying Yong Sheng Tai Xue Bao ; 18(8): 1681-7, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-17974229

RESUMO

Based on the investigation data from a 25 hm2 broadleaved Korean pine (Pinus koraiensis) mixed forest plot in Changbai Mountains of China, the dominant species Korean pine and Tilia amurensis were chosen as research objects. One point pattern analysis method, O-ring statistics, was used to analyze the spatial patterns of the species in three vertical layers, i. e., overstory, midstory and understory layers, and the spatial associations of intra- and inter-species between different vertical layers were studied. The results showed that P. koraiensis and T. amurensis were clumped at smaller scales. Higher layers tended to be randomly or regularly distributed, while lower layers tended to be aggregated at smaller scales. The aggregation degree decreased with canopy height. P. koraiensis stems in overstory layer were significantly positively associated to the stems in midstory layer at scales < 11 m, and T. amurensis in overstory layer showed negatively correlation with that in midstory and understory layers. There was generally a positive correlation between the two species, but the association varied among different layers. No significant correlation was observed between P. koraiensis stems in overstory layer and T. amurensis in three layers. P. koraiensis stems in midstory layer showed slightly negative correlation with T. amurensis in the same layer at scales > 4 m, but no significant association to T. amurensis in understroy layer. T. amurensis in overstory layer was significantly positively associated to P. koraiensis in midstory layer at scales < 100 m.


Assuntos
Ecossistema , Pinus/crescimento & desenvolvimento , Tilia/crescimento & desenvolvimento , Biomassa , China
16.
Ann Bot ; 100(2): 177-83, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17565972

RESUMO

BACKGROUND AND AIMS: In Tilia amurensis, two types of trichomes (hairy and glandular) develop from epidermal surfaces of cotyledons and hypocotyls of zygotic embryos soon after germination. Here, it is demonstrated that glandular trichome initials develop directly into somatic embryos when treated in vitro with 2,4-dichlorophenoxyacetic acid (2,4-D). METHODS: Zygotic embryos of Tilia amurensis were cultured on Murashige and Skoog medium with 3 % sucrose and various concentrations (0, 2.2, 4.4 and 8.8 microm) of 2,4-D. Morphological development of trichomes and somatic embryos was analysed by scanning electron microscope and light microscope after histological sectioning. KEY RESULTS: In zygotic embryos cultured on medium with 4.4 microM 2,4-D, formation of hairy trichomes was completely suppressed but formation of glandular trichome initials increased. That some filamentous trichome initials developed directly into somatic embryos was confirmed by histological and scanning electron microscope observation. When explants with different stages of trichome initials (two-, four- and eight-celled filamentous and fully mature trichomes) were temporally pre-treated with 4.4 microM 2,4-D for 24 h and transferred into hormone-free medium, two-celled and four-celled filamentous trichome initials were the effective stage of trichomes for somatic embryo induction. CONCLUSIONS: It is suggested that early developing filamentous trichome initials have developmental plasticity and that with 2,4-D treatment these trichome initials develop directly into somatic embryos.


Assuntos
Cotilédone/crescimento & desenvolvimento , Desenvolvimento Embrionário/fisiologia , Hipocótilo/crescimento & desenvolvimento , Epiderme Vegetal/crescimento & desenvolvimento , Tilia/crescimento & desenvolvimento , Ácido 2,4-Diclorofenoxiacético , Técnicas de Cultura , Tilia/embriologia
17.
Ying Yong Sheng Tai Xue Bao ; 17(9): 1575-8, 2006 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-17147159

RESUMO

Based on the measurements of leaf photosynthesis, the light response curves of Pinus koraiensis, Tilia amurensis, Quercus mongolica and Fraxinus mandshurica photosynthesis in broadleaved Korean pine forest of Changbai Mountains were fitted with rectangle and non-rectangle hyperbolae. The results showed that rectangle hyperbola was simpler for fitting, while non-rectangle hyperbola was more reasomable because of its fitted results better matched physiological meanings. The values of intrinsic quantum efficiency for CO2 uptake (alpha), light-saturated net photosynthetic rate (Pmax), and dark respiration rate (Rd) of the four tree species were higher when fitted with rectangle hyperbola than with non-rectangle hyperbola, while that of light compensation point (Lcp) varied with tree species. The values of alpha and Rd obtained from the two hyperholae had the same sequences, i.e., F. mandshurica > T. amurensis > Q. mongolica > P. koraiensis for alpha, and F. mandshurica > Q. mongolica > T. amurensis > P. koraiensis for Rd, but for Pmax and Lcp, the sequences were not the same.


Assuntos
Fotossíntese/fisiologia , Pinus/fisiologia , Quercus/fisiologia , Luz Solar , Tilia/fisiologia , China , Pinus/crescimento & desenvolvimento , Transpiração Vegetal , Quercus/crescimento & desenvolvimento , Tilia/crescimento & desenvolvimento
18.
Mycologia ; 98(2): 195-217, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16894965

RESUMO

Effects of forest management on fungal diversity were investigated by sampling fruit bodies of polyporoid and corticioid fungi in forest stands that have different management histories. Fruit bodies were sampled in 15 northern hardwood stands in northern Wisconsin and the upper peninsula of Michigan. Sampling was conducted in five old-growth stands, five uneven-age stands, three even-age unthinned stands and two even-age thinned stands. Plots 100 m x 60 m were established and 3000 m2 within each plot was sampled during the summers of 1996 and 1997. A total of 255 polyporoid and corticioid morphological species were identified, 46 (18%) of which could not be assigned to a described species. Species accumulation curves for sites and management classes differed from straight lines, although variability from year to year suggests that more than 2 y of sampling are needed to characterize annual variation. Mean species richness and diversity index values did not vary significantly by management class, although mean richness on large diameter wood (> or = 15 cm diam) varied with moderate significance. Richness values on small diameter debris varied significantly by year, indicating that a large part of year-to-year variability in total species richness is due to small diameter debris. Ten species had abundance levels that varied by management class. Two of these species. Changes in the diversity and species composition of the wood-inhabiting fungal community could have significant implications for the diversity, health and productivity of forest ecosystems.


Assuntos
Biodiversidade , Ecossistema , Agricultura Florestal , Polyporales/classificação , Árvores/crescimento & desenvolvimento , Árvores/microbiologia , Acer/crescimento & desenvolvimento , Acer/microbiologia , Betula/crescimento & desenvolvimento , Betula/microbiologia , Agricultura Florestal/métodos , Michigan , Polyporaceae/classificação , Polyporaceae/isolamento & purificação , Polyporales/isolamento & purificação , Tilia/crescimento & desenvolvimento , Tilia/microbiologia , Tsuga/crescimento & desenvolvimento , Tsuga/microbiologia , Wisconsin
19.
Phytochemistry ; 62(5): 707-13, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12620322

RESUMO

Xylem of lime trees (Tilia spp.) with wound reactions was structurally investigated by scanning (SEM) and transmission electron microscopy (TEM) as well as chemically analyzed by direct thermal desorption-gas chromatography-mass spectrometry (DTD-GC-MS). Wound reactions in the outer xylem lead to distinct discolorations around the wound. Within a 4-week response no fungal infection occurred in discoloured xylem. At the fine structural level, wound reactions become primarily visible as the secretion of dark-staining substances from parenchyma cells into lumens of vessels and fibres. With increasing reaction time vessels aggregate large amounts of secretion products, whereas in fibres wall-associated linings are formed and the inner secondary wall appears incrusted. After 2-3 months a narrow, greenish-brown boundary developed at the transition between the discoloured outer and the unchanged inner xylem. This green-brown boundary layer remained non-infected also in older wounds. DTD-GC-MS analyses revealed that the sesquiterpene Hydroxycalamenene represents a key substance of wound reactions in non-infected lime trees. Other substances such as fatty acids or their esters and coniferyl aldehydes or their derivatives were also found. TEM investigations of the samples after DTD-GC-MS showed less pronounced cell wall-attached linings in fibres as well as reduced incrustation of inner secondary walls. The massive deposits in the vessel lumens remained unchanged. The role of these wound reaction products and their ways of synthesis are discussed.


Assuntos
Sesquiterpenos/isolamento & purificação , Tilia/química , Fungos/ultraestrutura , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Doenças das Plantas/microbiologia , Estruturas Vegetais/química , Estruturas Vegetais/metabolismo , Estruturas Vegetais/ultraestrutura , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Estresse Mecânico , Tilia/crescimento & desenvolvimento , Tilia/metabolismo , Tilia/ultraestrutura , Fatores de Tempo
20.
Tree Physiol ; 22(15-16): 1167-75, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12414376

RESUMO

We investigated shoot growth patterns and their relationship to the canopy radiation environment and the distribution of leaf photosynthetic production in a 27-m-tall stand of light-demanding Populus tremula L. and shade-tolerant Tilia cordata Mill. The species formed two distinct layers in the leaf canopy and showed different responses in branch architecture to the canopy light gradient. In P. tremula, shoot bifurcation decreased rapidly with decreasing light, and leaf display allowed capture of multidirectional light. In contrast, leaf display in T. cordata was limited to efficient interception of unidirectional light, and shoot growth and branching pattern facilitated relatively rapid expansion into potentially unoccupied space even in the low light of the lower canopy. At the canopy level, T. cordata had higher photosynthetic light-use efficiency than P. tremula, whereas P. tremula had higher nitrogen-use efficiency than T. cordata. However, at the individual leaf level, both species had similar efficiencies under comparable light conditions. Production of new leaf area in the canopy followed the pattern of photosynthetic production. However, the species differed substantially in extension growth and space-filling strategy. Light-demanding P. tremula expanded into new space with a few long shoots, with shoot length strongly dependent on photosynthetic photon flux density (PPFD). Production of new leaf area and extension growth were largely uncoupled in this species because short shoots, which do not contribute to extension growth, produced many new leaves. Thus, in P. tremula, the growth pattern was strongly directed toward the top of the canopy. In contrast, in shade-tolerant T. cordata, shoot growth was weakly related to PPFD and more was invested in long shoot growth on a leaf area basis compared with P. tremula. However, this extension growth was not directed and may serve as a passive means of avoiding self-shading. This study supports the hypothesis that, for a particular species, allocation patterns and crown architecture contribute as much to shade tolerance as leaf-level photosynthetic acclimation.


Assuntos
Brotos de Planta/crescimento & desenvolvimento , Populus/crescimento & desenvolvimento , Tilia/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Luz , Nitrogênio/análise , Fotossíntese/fisiologia , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Brotos de Planta/anatomia & histologia , Populus/anatomia & histologia , Tilia/anatomia & histologia , Árvores/anatomia & histologia
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