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1.
Sci Total Environ ; 750: 141306, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32846245

RESUMO

Tree mortality associated with drought and concurrent bark beetle outbreaks is expected to increase with further climate change. When these two types of disturbance occur in concert it complicates our ability to accurately predict future forest mortality. The recent extreme California USA drought and bark beetle outbreaks resulted in extensive tree mortality and provides a unique opportunity to examine questions of why some trees die while others survive these co-occurring disturbances. We use plot-level data combined with a three-proxy tree-level approach using radial growth, carbon isotopes, and resin duct metrics to evaluate 1) whether variability in stand structure, tree growth or size, carbon isotope discrimination, or defenses precede mortality, 2) how relationships between these proxies differ for surviving and now-dead trees, and 3) whether generalizable risk factors for tree mortality exist across pinyon pine (Pinus monophylla), ponderosa pine (P. ponderosa), white fir (Abies concolor), and incense cedar (Calocedrus decurrens) affected by the combination of drought and beetle outbreaks. We find that risk factors associated with mortality differ between species, and that few generalizable patterns exist when bark beetle outbreaks occur in concert with a particularly long, hot drought. We see evidence that both long-term differences in physiology and shorter-term beetle-related selection and variability in defenses influence mortality susceptibility for ponderosa pine, whereas beetle dynamics may play a more prominent role in mortality patterns for white fir and pinyon pine. In contrast, incense cedar mortality appears to be attributable to long-term effects of growth suppression. Risk factors that predispose some trees to drought and beetle-related mortality likely reflect species-specific strategies for dealing with these particular disturbance types. The combined influence of beetles and drought necessitates the consideration of multiple, species-specific risk factors to more accurately model forest mortality in the face of similar extreme events more likely under future climates.


Assuntos
Besouros , Pinus , Animais , Surtos de Doenças , Secas , Casca de Planta , Árvores
2.
Sci Total Environ ; 751: 141728, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32890797

RESUMO

Trees significantly impact land-atmosphere feedbacks through evapotranspiration, photosynthesis and isoprene emissions. These processes influence the local microclimate, air quality and can mitigate temperature extremes and sequester carbon dioxide. Despite such importance, currently only 5 out of 15 atmospheric chemistry climate models even partially account for the presence of cropland trees. We first show that the tree cover over intensely farmed regions in Asia, Australia and South America is significantly underestimated (e.g. only 1-3% tree cover over north-India) in the Model of Emissions of Gases and Aerosol from Nature (MEGAN) and absent in Noah land-surface module of the Weather Research and Forecasting (WRF-Chem) Model. By including the actual tree cover (~10%) over the north-west Indo Gangetic Plain in the Noah land-surface module of the WRF-Chem and the MEGAN module, during the rice growing monsoon season in August, we find that the latent heat flux alone increases by 100%-300% while sensible heat flux reduces by 50%-100%, leading to a reduction in daytime boundary layer height by 200-400 m. This greatly improves agreement between the modelled and measured temperature, boundary layer height and surface ozone, which were earlier overestimated and isoprene and its oxidation products which were earlier underestimated. Mitigating peak daytime temperatures and ozone improves rice production by 10 to 20%. Our findings from north west Indo-Gangetic Plain establish that such plantations mitigate heat stress, and have beneficial effects on crop yields while also sequestering carbon. Expanding agroforestry practices to 50% of the cropland area could result in up to 40% yield gain regionally. Implementing such strategies globally could increase crop production and sequester 0.3-30 GtC per year, and therefore future climate mitigation and food security efforts should consider stakeholder participation for increased cropland agroforestry in view of its beneficial effects.


Assuntos
Poluentes Atmosféricos , Ozônio , Poluentes Atmosféricos/análise , Ásia , Atmosfera , Austrália , Produtos Agrícolas , Monitoramento Ambiental , Índia , Ozônio/análise , América do Sul , Temperatura , Árvores
3.
Sci Total Environ ; 751: 141851, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32898748

RESUMO

Worldwide increases in droughts- and heat-waves-associated tree mortality events are destabilizing the future of many forests and the ecosystem services they provide. Along with climate, understanding the impact of the legacies of past forest management is key to better explain current responses of different tree species to climate change. We studied tree mortality events that peaked in 2012 affecting one native (silver fir; growing within its natural distribution range) and two introduced (black pine and Scots; growing outside their natural distribution range) conifer species from the Romanian Carpathians. The three conifers were compared in terms of mortality events, growth trends, growth resilience to severe drought events, climate-growth relationships, and regeneration patterns. The mortality rates of the three species were found to be associated with severe drought events. Nevertheless, the native silver fir seems to undergo a self-thinning process, while the future of the remaining living black pine and Scots pine trees is uncertain as they register significant negative growth trends. Overall, the native silver fir showed a higher resilience to severe drought events than the two introduced pine species. Furthermore, and unlike the native silver fir, black pine and Scots pine species do not successfully regenerate. A high diversity of native broadleaf species sprouts and develops instead under them suggesting that we might be witnessing a process of ecological succession, with broadleaves recovering their habitats. As native species seem to perform better in terms of resilience and regeneration than introduced species, the overall effect of the black pine and Scots pine mortality might be compensated. Legacies of past forest management should be taken into account in order to better understand current responses of different tree species to ongoing climate change.


Assuntos
Secas , Traqueófitas , Ecossistema , Florestas , Romênia , Árvores
4.
Sci Total Environ ; 752: 141752, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32898798

RESUMO

Large scale afforestation mainly for erosion control or timber production and a very strict logging ban policy in recent decades led to many over-dense stands and remarkable water yield reduction in the dryland region of the Loess Plateau in northwest China. To guide the integrated forest-water management at stand level, a study on the response of water yield from larch (Larix principis-rupprechtii) plantations to key stand structure and site factors was carried out in the Liupan Mountains. Models of leaf area index (LAI) of forest canopy and stand evapotranspiration (ET) in the growing season were developed and fitted. The growing season water yield was calculated based on water budget. The results showed that: (1) The LAI increases with rising tree density firstly quickly and then slowly and finally tending to its maximum; but firstly increases and then decreases with rising tree age and elevation. The LAI model coupling the effects of tree density, age, and elevation works well. (2) The ET model reflecting the coupled effects of precipitation, potential evapotranspiration, LAI and soil moisture can well predict the ET variation. (3) The water yield decreases gradually with rising tree density, but firstly decreases and then increases with rising tree age and elevation. The lowest water yield appears at the age of 30 years and at an elevation of 2420 m. (4) The implications of this study for integrated forest-water management are: defining water yield as the dominant forest service at high or low elevations, but quality timber production as the dominant service at medium elevations; arranging rational thinning for dense forests around the age of 30 years; designing a mosaic distribution of forest ages within watersheds. Applying the study outcomes can promote the integration of water yield management with traditional forest management to ensure the sustainability of water supply in dryland regions.


Assuntos
Larix , China , Solo , Árvores , Água
5.
Sci Total Environ ; 752: 141794, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32898800

RESUMO

Covering large parts of Europe, Norway spruce (Picea abies L Karst.) plays an important role in the adaptation strategy of forest services to future climate change. Although dendroecology can provide valuable information on the past relationships between tree growth and climate, most previous studies were biased towards species-specific distribution limits, where old individuals grow slowly under extreme conditions. In the present study, we investigated the growth variability and climate sensitivity of 2851 Norway spruce trees along longitudinal (E 12-26°), latitudinal (N 45-51°), and elevation (118-1591 m a.s.l.) gradients in central-eastern Europe. We reveal that summer weather significantly affects the radial growth of spruce trees, but the effects strongly vary along biogeographical gradients. Extreme summer heatwaves in 2000 and 2003 reduced the growth rates by 10-35%, most pronounced in the southern Carpathians. In contrast to the population in the Czech Republic, climate warming induced a synchronous decline in the growth rates across biogeographical gradients in the Carpathian arc. By demonstrating the increased vulnerability of Norway spruce under warmer climate conditions, we recommended that the forest services and conservation managers replace or admix monocultures of this species with more drought-resilient mixtures including fir, beech and other broadleaved species.


Assuntos
Picea , Mudança Climática , República Tcheca , Europa (Continente) , Europa Oriental , Humanos , Noruega , Árvores
6.
Sci Total Environ ; 753: 141934, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32889317

RESUMO

Secondary forests emerging during traditional shifting cultivation practices are increasingly recognized for their fulfillment of ecosystem services and mitigation potential of climate change and biodiversity losses. The soil seed bank as a recruit reservoir is a limiting factor for natural forest regeneration of such secondary forests and is decisive for the formation and restitution of the post-disturbance community. The aim of this study was to compare the composition of the soil seed bank along a natural regeneration chronosequence from the Caxiuanã National Forest, eastern Amazon, including old-growth reference sites. We sampled standing vegetation, soil properties and soil seed banks and compared the density and species richness of different life forms among different regeneration stages. Using nonmetric, multiple scaling, we compared the composition of the soil seed bank among different regeneration stages and with standing vegetation composition. Furthermore, we outlined the influence of stand age, vegetation structure and soil properties on the density, richness and functional characterization of the soil seed bank using mixed effect models. The soil seed bank was dominated by herb seeds in all regeneration stages, and the density and richness of tree seeds increased with regeneration time and recovery of vegetation structure. Seed bank composition changed gradually with regeneration advance and differed from standing vegetation, containing a high amount of allochthonous seeds, especially in older stands. This observation highlights the importance of dispersal and habitat connectivity for the natural regeneration of these secondary forests. Shifts in soil seed bank composition towards slow-growing, animal-dispersed, non-pioneer species with larger, recalcitrant seeds in older regeneration stands indicate changes in vegetation composition along succession. Thus, our data indicate the importance of connectivity for forest regeneration and long fallow periods (> 40 years) to increase the performance of ecosystem services, resilience and stability of secondary forests arising during shifting cultivation practices.


Assuntos
Banco de Sementes , Solo , Ecossistema , Florestas , Sementes , Árvores
7.
Sci Total Environ ; 751: 142335, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33181979

RESUMO

Forest soils are being exposed to nutrient deficiency and acidification at increasing rates as a result of intensive management. Mineral fertilization, however, provides a way to improve soil nutrient balance. The aim of this study is to present the effects of mineral fertilization on the properties of forest soil 11 years after fertilization. Our research investigated the effects of dolomite, magnesite and serpentinite fertilization on the physicochemical properties of the soil, soil biological activity, and fungal diversity. We also determined the condition of a new generation of fir trees after mineral fertilization. In autumn, 2008, fertilizers (dolomite, magnesite and serpentinite, specifically) in the amount of 4000 kg.ha-1 were added to plots in the Wisla Forest District in Poland; one area was left unfertilized to act as the control area for this research. Our results reveal that all fertilization improved the selected soil's physicochemical properties (pH, Ca and Mg content) and accordingly, its biochemical activity; in particular, we found that dolomite (4000 kg.ha-1) contributed heavily to soil improvement. The findings also showed that soil pH and calcium content were strongly dependent on enzymatic activity, while dolomite fertilization resulted in a significant increase in biomass size in the fir trees included in this study. In addition to being associated with the highest plant biomass and amounts of enzymatic activity, dolomite-fertilized soil also had the highest number of fungal operational taxonomic units (OTUs): 403, compared to 322 OTUs in the control soil. Finally, the fungal communities in the control soil varied significantly from the fungal communities in soils fertilized with dolomite and serpentinite. The results of this research support mineral fertilization, and in particular, fertilization using dolomite in amounts of 4000 kg.ha-1, to improve soil nutrient supply and to shape the biological activity expressed by the enzymatic activity of forest soils.


Assuntos
Ecossistema , Solo , Florestas , Polônia , Microbiologia do Solo , Árvores
8.
Sci Total Environ ; 747: 142084, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33076212

RESUMO

Forest habitats change significantly under the influence of global warming. It is important to predict the effects of these changes, especially in primeval forests which currently represent a small percentage of temperate forests. Such changes often manifest themselves in an acceleration of the frequency of mass seeding of trees, which causes cascading effects in various organisms. We evaluated changes in: tree masts (oak Quercus robur and hornbeam Carpinus betulus), rodent abundance (yellow-necked mouse Apodemus flavicollis), folivorous caterpillar abundance (winter moth Operophtera brumata), and the breeding success of a cavity-nesting songbird (collared flycatcher Ficedula albicollis) in over a 30-year period in the Bialowieza Forest (E Poland). We also analysed temperature, precipitation and snow cover to determine the effects of weather on each trophic level. Previous studies have exposed the indirect effect of tree masting on songbirds breeding in open nests. Our study uniquely highlights the relationships between trees, rodents, caterpillars, and a cavity-nesting bird. Precipitation was positively correlated with the fructification of trees, abundance of caterpillars, and the breeding losses of flycatchers (in July, August, October in the previous year, in May in the current year, respectively). We found that along with the changing climate, the frequency of mast years of oak increased, which caused an increasing frequency of rodent outbreaks. The abundance of mice was positively correlated with the predation on flycatcher broods (current year) and negatively - with the abundance of caterpillars (following year). We predict that current global trends in climate change will have a negative impact on the flycatcher due to the cascading effects from the above species. Bearing in mind that F. albicollis is one of the most numerous bird species, it can be assumed that more frequent masting will result in substantial changes in the entire bird assemblage, and presumably also other groups of animals.


Assuntos
Aves Canoras , Árvores , Animais , Cruzamento , Mudança Climática , Florestas , Camundongos , Polônia
9.
Zootaxa ; 4779(3): zootaxa.4779.3.1, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33055775

RESUMO

We conducted a taxonomic revision of the arboreal snakes of the Boiga ceylonensis-group, all inhabiting the Indian subcontinent. Based on 15 characters, recorded from more than 100 specimens, representing eight recognized taxa, we conducted a multivariate morphometric analysis to redefine the taxonomic boundaries. We provide redescriptions of the nominate taxa in this group based on re-examination of the name-bearing types. The types of B. ceylonensis, B. beddomei, B. barnesii, B. dightoni, B. nuchalis and B. andamanensis are redescribed, where appropriate lectotypes are selected, illustrated and their nomenclature, synonymy and distribution are discussed. Status of the nominate taxon Boiga ceylonensis dakhunensis Deraniyagala, 1955 is fixed as an objective junior synonym of Dipsas nuchalis Günther, 1875. An updated key to the species of this group is presented.


Assuntos
Colubridae , Distribuição Animal , Animais , Árvores
10.
Zootaxa ; 4845(2): zootaxa.4845.2.12, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-33056781

RESUMO

Dendrothripinae is a small sub-family in Thripidae which has a characteristically sinuate metathoracic endofurca reaching into the mesothorax. This structure is associated with the large muscles that are involved in jumping, and a similar metathoracic furca occurs in some Panchaetothripinae members as well as Trachynotothrips in the Thripinae (Mound 1999; Masumoto Okajima 2005). There are 12 extant genera and more than 100 species of Dendrothripinae, almost all feeding on leaves (ThripsWiki 2020). A few species are considered as pests, like Dendrothrips minowai and Pseudodendrothrips mori that damage the tea plant and mulberry respectively. An identification key to world genera of Dendrothripinae (except Projectothripoides) is available (Mound Tree 2016), and 14 species representing six genera are recorded in Japan (Masumoto Okajima 2017). Mirab-balou et al. (2011) provided a list of thrips in China including 15 Dendrothripinae species representing three genera: Asprothrips, Dendrothrips, and Pseudodendrothrips. Subsequently, three new species of Asprothrips have been described from this country (Tong et al. 2016, Wang Tong 2017) and two other genera, Edissa and Ensiferothrips, were found in Southern China (Zhang et al. 2018). Just recently, Wang et al. (2019) provided a key to 10 Dendrothrips species from China, including one new species. Therefore, five genera and 26 species of Dendrothripinae are recorded in China up to now (Zhang et al. 2018).


Assuntos
Morus , Tisanópteros , Animais , China , Árvores
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2812-2815, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018591

RESUMO

Cardiovascular diseases are nowadays considered as the main cause of morbidity and mortality worldwide. Coronary Artery Disease (CAD), the most typical form of cardiovascular disease is diagnosed by a variety of imaging modalities, both invasive and non-invasive, which involve either risk implications or high cost. Therefore, several attempts have been undertaken to early diagnose and predict either the high CAD risk patients or the cardiovascular events, implementing machine learning techniques. The purpose of this study is to present a classification scheme for the prediction of Percutaneous Coronary Intervention (PCI) stenting placement, using image-based data. The proposed classification model is a gradient boosting classifier, incorporated into a class imbalance handling technique, the Easy ensemble scheme and aims to classify coronary segments into high CAD risk and low CAD risk, based on their PCI placement. Through this study, we investigate the importance of image based features, concluding that the combination of the coronary degree of stenosis and the fractional flow reserve achieves accuracy 78%.


Assuntos
Doença da Artéria Coronariana , Reserva Fracionada de Fluxo Miocárdico , Intervenção Coronária Percutânea , Doença da Artéria Coronariana/diagnóstico por imagem , Humanos , Stents , Árvores
12.
Zootaxa ; 4759(3): zootaxa.4759.3.8, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33056911

RESUMO

Drypetothrips korykis gen. et sp.n. is described as inducing leaf-margin galls on a small tree in Australia, Drypetes deplanchei [Putranjivaceae]. This thrips is similar in appearance to the smaller species of the genus Kladothrips that induce galls on Acacia species. The galls are invaded by a phytophagous kleptoparasitic thrips, Pharothrips hynnis gen. et sp.n., females of which have a forked plough-like structure protruding ventrally on the frons that is unique amongst Thysanoptera.


Assuntos
Acacia , Tisanópteros , Animais , Feminino , Folhas de Planta , Árvores
13.
J Environ Qual ; 49(1): 163-171, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016370

RESUMO

Annual and multiyear records of trace element deposition are difficult to develop using monitoring systems but have proven feasible using plant material in several settings. Here, we used material from several tree species (Populus deltoides W. Bartram ex Marshall, Platanus occidentalis L., and Ginkgo biloba L.) to detect atmospheric deposition of trace elements (Cd, Cu, Pb, and Zn) in six localities along a transect from near-urban to far-urban in southeastern Indianapolis, IN, and one control site. We captured soil (legacy footprint), bark (multiannual record), and leaves (seasonal record) across a broad swath of the urban landscape and using a multi-metal approach. Tree bark, leaf, and proximal soil samples were collected and analyzed for their trace element content. The highest trace metal concentrations occurred at the near-urban sites, with particularly high Cu and Pb values. The highest Zn values were found at one of the far-urban sites, which is located near a large brownfield that was a former coal and coke storage and processing facility. No correlation was found between soil trace element composition and that of bark and leaves, perhaps indicating a disconnect between legacy inputs recorded in soils and current inputs recorded in the biological materials. Overall, the tree species analyzed served well as trace element bioindicators, although less so for G. biloba, and thus this approach is promising for further understanding the role that airborne pollution and deposition play in urban watersheds.


Assuntos
Oligoelementos/análise , Biomarcadores Ambientais , Monitoramento Ambiental , Solo , Árvores
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 5343-5346, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019190

RESUMO

In-silico clinical platforms have been recently used as a new revolutionary path for virtual patients (VP) generation and further analysis, such as, drug development. Advanced individualized models have been developed to enhance flexibility and reliability of the virtual patient cohorts. This study focuses on the implementation and comparison of three different methodologies for generating virtual data for in-silico clinical trials. Towards this direction, three computational methods, namely: (i) the multivariate log-normal distribution (log- MVND), (ii) the supervised tree ensembles, and (iii) the unsupervised tree ensembles are deployed and evaluated against their performance towards the generation of high-quality virtual data using the goodness of fit (gof) and the dataset correlation matrix as performance evaluation measures. Our results reveal the dominance of the tree ensembles towards the generation of virtual data with similar distributions (gof values less than 0.2) and correlation patterns (average difference less than 0.03).


Assuntos
Cardiomiopatias , Árvores , Simulação por Computador , Desenvolvimento de Medicamentos , Humanos , Reprodutibilidade dos Testes
15.
Ann Bot ; 126(5): 957-969, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33026086

RESUMO

BACKGROUND AND AIMS: The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. METHODS: We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. KEY RESULTS: The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season's cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. CONCLUSIONS: For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.


Assuntos
Herbivoria , Árvores , Feminino , Flores , Folhas de Planta , Reprodução
16.
Oecologia ; 194(3): 359-370, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33030569

RESUMO

Forests in the western United States are being subject to more frequent and severe drought events as the climate warms. The 2012-2015 California drought is a recent example, whereby drought stress was exacerbated by a landscape-scale outbreak of western pine beetle (Dendroctonus brevicomis) and resulted in widespread mortality of dominant canopy species including ponderosa pine (Pinus ponderosa). In this study, we compared pairs of large surviving and beetle-killed ponderosa pines following the California drought in the southern Sierra Nevadas to evaluate physiological characteristics related to survival. Inter-annual growth rates and tree-ring stable isotopes (∆13C and δ18O) were utilized to compare severity of drought stress and climate sensitivity in ponderosa pines that survived and those that were killed by western pine beetle. Compared to beetle-killed trees, surviving trees had higher growth rates and grew in plots with lower ponderosa pine basal area. However, there were no detectable differences in tree-ring ∆13C, δ18O, or stable isotope sensitivity to drought-related meteorological variables. These results indicate that differences in severity of drought stress had little influence on local, inter-tree differences in growth rate and survival of large ponderosa pines during this drought event. Many previous studies have shown that large trees are more likely to be attacked and killed by bark beetles compared to small trees. Our results further suggest that among large ponderosa pines, those that were more resistant to drought stress and bark beetle attacks were in the upper echelon of growth rates among trees within a stand and across the landscape.


Assuntos
Besouros , Pinus , Animais , California , Secas , Florestas , Pinus ponderosa , Árvores
17.
Nature ; 587(7832): 42-43, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33057187
18.
Huan Jing Ke Xue ; 41(8): 3518-3526, 2020 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124324

RESUMO

In order to understand the emission characteristics of common greening trees in Beijing and analyze their correlations with photosynthetic parameters, including the net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (ci), and transpiration rate (Tr), we collected samples of biogenic volatile organic compounds (BVOCs) using a dynamic sampling technique from 14 species of deciduous trees. The results showed that there were significant differences in isoprene and total BVOC emissions between family or genus levels (P<0.01). With the exception of Lonicera maackii Maxim and Ulmus pumila L., all species were found to emit isoprene, monoterpenes, and sesquiterpenes, of which, species from the Salicaceae (e.g., Populus deltoides cv. '55/56'× P.deltoides cv. 'Imperial', P. euramericana cv. '74/76', Populus simonii Carr, and Salix babylonica) and Legume (Sophora japonica, Robinia pseudoacacia, and S. japonica Linn. var. japonica f. pendula Hort) families were the higher isoprene emitters, with emission rates that ranged from (30.1±4.3) µg·(g·h)-1 to (91.8±10.0) µg·(g·h)-1. Plants from the Oleaceae (e.g., Fraxinus chinensis Roxb and Syringa oblata Lindl), Begonia (Malus prunifolia), Sapindaceae (Koelrenteria paniculate), and Aceraceae (Acer truncatum Bunge) families mainly emitted monoterpenes and sesquiterpenes. Among them, Fraxinus chinensis Roxb and Acer truncatum Bunge were the highest emitters with emission rates of (10.6±4.8) µg·(g·h)-1 and (11.8±6.4) µg·(g·h)-1, respectively. Ocimene and ß-pinene were the two main monoterpenes emitted from greening tree species. No significant correlations were found between the emission of BVOCs and Pn or gs, while the emission rate of isoprene (r=0.681; P<0.01) and the total BVOC (r=0.698; P<0.01) from the Salicaceae family increased with increasing Tr. Moreover, leguminous plants showed a significant positive correlation between the total BVOC emission rate and ci (P=0.04). This study provides a scientific reference for the selection and configuration of urban greenery, and a theoretical basis for exploring the mechanism of BVOC emissions.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Pequim , China , Árvores , Compostos Orgânicos Voláteis/análise
19.
An Acad Bras Cienc ; 92(3): e20200410, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33111822

RESUMO

Biological invasion is a major threat to global biodiversity and ecosystem services. We examined the functional traits similarity between a set of native and non-native invasive tree species from the Southern Brazilian subtropical mixed forest, part of an important global hotspot for biodiversity conservation. We hypothesized that invasive species occupy marginal niche spaces. We ordered the species using the Principal Component Analysis based on their wood density, leaf area, and specific leaf area. These are all important traits that summarize essential ecological strategies associated with resource acquisition and conservation. Functional overlaps between non-native and native species were analyzed through kernel density estimation of continuous traits data. While native and non-native invasive species were distributed along the same functional gradients, the position of non-native species in the functional space is species and traits specific. We concluded that within Brazilian subtropical mixed forests, the functional dissimilarity as a key factor in invasion success could not be generalized for all species and traits.


Assuntos
Biodiversidade , Espécies Introduzidas , Árvores , Brasil , Ecossistema , Florestas
20.
Environ Monit Assess ; 192(11): 740, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33128682

RESUMO

Studies of soil bulk density (BD) spatial variations of land reclaimed after mining have become a focus of land reclamation and ecological restoration research. However, there have been few studies on the relationship among the reconstructed BD, terrain conditions, and vegetation growth. We examined the southern dumping site of the Pingshuo Antaibao open-pit coal mine located in a loess area in China. Field sampling data, digital elevation models (DEMs), and high-definition images were obtained, and indoor testing, geostatistics, and inverse distance weighting (IDW) were applied. This paper aims to analyze the spatial distribution law of the reconstructed BD and focus on its relationship with slope and vegetation allocation models. We demonstrated that (1) BD increased with soil depth and varied moderately within each layer. (2) The BD variation amplitude of the top 0-20-cm soil layer in both the east-west and south-north directions was small and more similar in the east-west direction than in the south-north direction, which was affected by herbaceous root systems. In the next four layers from 20 to 60 cm, the variation in BD in the east-west direction was far larger than that in the south-north direction, which was affected by vegetation classification. (3) On the whole, BD decreased with increasing slope, but when the slope was between 0° and 21°, BD exhibited a specific change law. (4) From the perspective of vegetation classification, the orders of magnitude of BD in the 0-20-cm and 20-60-cm layers differed. Overall, BD in areas vegetated with Korshinsk Peashrub was the lowest, and BD was moderate in areas with mixed vegetation, while BD was the highest in areas without vegetation or only vegetated with Black Locust. The mixed grass-bush-tree or bush-tree mode attained the best effect in regulating BD. These results can improve the basic principles of land reclamation in mining areas and provide a basis for further optimizing land reclamation technology in practice.


Assuntos
Monitoramento Ambiental , Solo , China , Mineração , Árvores
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