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1.
Science ; 366(6463)2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31624179

RESUMO

Bastin et al (Reports, 5 July 2019, p. 76) state that the restoration potential of new forests globally is 205 gigatonnes of carbon, conclude that "global tree restoration is our most effective climate change solution to date," and state that climate change will drive the loss of 450 million hectares of existing tropical forest by 2050. Here we show that these three statements are incorrect.


Assuntos
Florestas , Árvores , Carbono , Mudança Climática
2.
Science ; 366(6463)2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31624183

RESUMO

Bastin et al (Reports, 5 July 2019, p. 76) claim that global tree restoration is the most effective climate change solution to date, with a reported carbon storage potential of 205 gigatonnes of carbon. However, this estimate and its implications for climate mitigation are inconsistent with the dynamics of the global carbon cycle and its response to anthropogenic carbon dioxide emissions.


Assuntos
Ciclo do Carbono , Árvores , Dióxido de Carbono , Mudança Climática
3.
Science ; 366(6463)2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31624182

RESUMO

Bastin et al's estimate (Reports, 5 July 2019, p. 76) that tree planting for climate change mitigation could sequester 205 gigatonnes of carbon is approximately five times too large. Their analysis inflated soil organic carbon gains, failed to safeguard against warming from trees at high latitudes and elevations, and considered afforestation of savannas, grasslands, and shrublands to be restoration.


Assuntos
Solo , Árvores , Carbono , Sequestro de Carbono , Mudança Climática
4.
Science ; 366(6463)2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31624184

RESUMO

Our study quantified the global tree restoration potential and its associated carbon storage potential under existing climate conditions. We received multiple technical comments, both supporting and disputing our findings. We recognize that several issues raised in these comments are worthy of discussion. We therefore provide a detailed common answer where we show that our original estimations are accurate.


Assuntos
Clima , Árvores , Carbono , Mudança Climática
5.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3327-3335, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621218

RESUMO

Carbon isotope in tree ring is an effective indicator of climate and environmental change. However, few studies have analyzed the indication effect of tree ring carbon isotope on net primary productivity (NPP) of forests. Based on meteorological factors of growing seasons, we analyzed the variation trend and the relationship between the tree ring δ13C chronosequence of Korean pine (Pinus koraiensis) and net primary productivity (NPP) of Korean pine in Changbai Mountain. We found that before 1970, the change of Korean pine tree ring δ13C and NPP was synchronous, with a highly significant linear positive correlation between them, indicating that tree ring δ13C recorded the impacts of climate change on NPP. After 1970, tree ring δ13C was negatively correlated with NPP but not statistically significant, meaning that other environmental factors such as severe droughts reduced the sensitivity of tree ring δ13C to climate change and the recording of NPP by tree ring δ13C. The δ13C of the current year was also correlated with the corresponding NPP in the following year, which indicated that the current year's environmental conditions were of great significance to the growth of Korean pine in the following year. This study showed that tree ring δ13C was a good indicator of the NPP of Korean pine in Changbai Mountain and that tree ring δ13C had the potential to reconstruct long-term changes of forest NPP in the history.


Assuntos
Pinus , Árvores , China , Mudança Climática , Florestas
6.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3356-3366, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621221

RESUMO

To reveal the seedlings dynamics of dominant trees and their response to canopy changes (as indicated by changes in leaf area index), we analyzed the seedlings dynamics of dominant trees and canopy structure during forest regeneration based on three-year (2014 to 2016) censuses and hemispherical photography in a 4 hm2 forest dynamics monitoring plot. The results showed that canopy LAI first decreased and then increased during the survey period, with significant interannual difference. The seedlings of 12 dominant tree species showed notable response to the change of canopy structure, with the response varying among different tree species. The relative abundance or frequency of seedlings for neutral tree species generally increased with the decreases of canopy LAI. The relative abundance or frequency of seedlings of light-demanding tree species generally decreased with the increases of canopy LAI. In multi-response permutation procedures by analyzing the numeric composition and distribution of dominant tree seedlings, there was significant difference among the three censuses. Such interannual difference gradually decreased from 2014 to 2016. Significant change occurred in the indicator species of dominant tree seedlings, reflecting their responses to the changes of canopy structure.


Assuntos
Plântula , Árvores , China , Florestas , Folhas de Planta
7.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3385-3394, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621224

RESUMO

To promote the application of domestic high-resolution satellite data in large-scale carbon storage estimation and measurement, a total of 206 high-resolution remote sensing images covering Hunan Province were used as the data source, and the estimated minimum unit was fixed as a 0.06 hm2 square composed of multiple pixels. Through the establishment and purification of the interpretation marks, in the extraction of forest information, the pixel-based method and object-oriented classification method were used to compare. In the estimation of carbon storage of arbor forest, the robust estimate, partial least squares method and k-NN estimate were used to compare. Finally, we estimated forest carbon storage in Hunan Province and generated the distribution map of carbon density levels. The results showed that the interpretation mark based on the automatic extraction of plots could increase the extraction accuracy of arbor forest after purification. For the estimation of forest carbon storage at large-scale, the k-NN algorithm embodied a large advantage in forest information extraction and arbor forest carbon storage modeling. The average classification accuracy of the 206 scene images was 76.8%, the average RMSE was 8.95 t·hm-2, the average RRMSE was 19.1%, and the total carbon stock in Hunan Province was 22.28 Mt. The results provided effective reference for the estimation and measurement of forest carbon storage at the provincial and national scales.


Assuntos
Sequestro de Carbono , Carbono , China , Florestas , Árvores
8.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3395-3402, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621225

RESUMO

Taihang Mountains is located on the eastern edge of the second step of Chinese topography, which is the natural boundary between Loess Plateau and North China Plain and is considered as one of the important priority areas for biodiversity conservation in China. We took 108 counties involved in the generalized Taihang Mountains as the research area to systematically analyze the characteristics of family and genus characters, floristic composition, geographical pattern of plant diversity and species richness hotspots at community level of mountain forests in Taihang Mountains. A total of 963 species of seed plants belonging to 447 genera and 100 families were recorded in 778 forest plots in Taihang Mountains. Within all the species, 12 species of gymnosperms belonging to 7 genera of 3 families, 951 species of angiosperms belonging to 440 genera of 97 families. Herbaceous plants (71.1%) was the dominant life form. The distribution types of families were mainly tropical (38%) and temperate (24%), and the distribution types of genera were mainly temperate (68.7%). The horizontal distribution pattern of plant diversity showed a trend of increasing from southwest to northeast. Species richness was positively correlated with the latitude and longitude. However, the richness patterns of different life-form plants were different, in that herbaceous richness was positively correlated with the longitude and latitude but that of woody plants was not. In the vertical gradient, plant richness of Taihang Mountains presented a single-peak distribution, which was concentrated in the low and middle elevations of 400-1800 m and peaked at 1000-1200 m. Based on the community inventory data, we mapped plant richness of Taihang Mountain forest community. The mountain areas such as Xiaowutai Mountain, Yuntai Mountain, Taiyue Mountain, Wangwu Mountain and Zhongtiao Mountain were identified as hotspots of plant richness, which should be included in the key planning and management areas of the Taihang Mountains priority protection.


Assuntos
Ecossistema , Florestas , Biodiversidade , China , Plantas , Inquéritos e Questionários
9.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3411-3418, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621227

RESUMO

To explore the distribution of fungal community in soil of brown coniferous forest in Daxing'anling and its relationship with soil characteristics, soil fungal community structure and diversity in three forest types, light brown coniferous forest, grass brown coniferous forest, and typical brown coniferous forest, were analyzed by high-throughput sequencing technology. The relationship between soil fungal community and soil characteristics was analyzed by R and SPSS 17.0 software. The results showed that soil physical and chemical characteristics differed significantly across the three brown coniferous forests. A total of 111 species belonged to six phyla, 23 class, 46 orders, 74 families and 88 genera were recorded in this study. Ascomycetes and basidiomycetes were dominant phyla. There were significant differences in relative abundance of phyla among three forest types. There was no significant difference in the Ace and Chao1 diversity indices among three brown coniferous forests, whereas there were significant differences in the Shannon and Simpson indices. Results from canonical correlation analysis and correlation analysis showed that both α and ß diversity were significantly correlated with soil moisture, soil pH, soil organic matter, soil total nitrogen, and soil total potassium. The results indicated that soil characteristics were important factors affecting soil fungal diversity of brown coniferous forest in Xing'an larch forest in Daxing'anling.


Assuntos
Coniferophyta , Solo , China , Florestas , Fungos
10.
Science ; 366(6463)2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31624185

RESUMO

Bastin et al (Reports, 5 July 2019, p. 76) neglect considerable research into forest-based climate change mitigation during the 1980s and 1990s. This research supports some of their findings on the area of land technically suitable for expanding tree cover, and can be used to extend their analysis to include the area of actually available land and operational feasibility.


Assuntos
Florestas , Árvores , Mudança Climática
15.
An Acad Bras Cienc ; 91(4): e20180666, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31644642

RESUMO

Here we model and describe the wood volume of Cerrado Sensu Stricto, a highly heterogeneous vegetation type in the Savanna biome, in the state of Minas Gerais, Brazil, integrating forest inventory data with spatial-environmental variables, multivariate regression, and regression kriging. Our study contributes to a better understanding of the factors that affect the spatial distribution of the wood volume of this vegetation type as well as allowing better representation of the spatial heterogeneity of this biome. Wood volume estimates were obtained through regression models using different environmental variables as independent variables. Using the best fitted model, spatial analysis of the residuals was carried out by selecting a semivariogram model for generating an ordinary kriging map, which in turn was used with the fitted regression model in the regression kriging technique. Seasonality of both temperature and precipitation, along with the density of deforestation, explained the variations of wood volume throughout Minas Gerais. The spatial distribution of predicted wood volume of Cerrado Sensu Stricto in Minas Gerais revealed the high variability of this variable (15.32 to 98.38 m3 ha-1) and the decreasing gradient in the southeast-northwest direction.


Assuntos
Biomassa , Florestas , Madeira , Brasil , Geografia , Análise Espacial
16.
Sci Total Environ ; 690: 1120-1130, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31470475

RESUMO

Ecosystem models have been widely used for obtaining gross primary productivity (GPP) estimations at multiple scales. Leaf area index (LAI) is a critical variable in these models for describing the vegetation canopy structure and predicting vegetation-atmosphere interactions. However, the uncertainties in LAI datasets and the effects of their representation on simulated GPP remain unclear, especially over complex terrain. Here, five most popular datasets, namely the Long-term Global Mapping (GLOBMAP) LAI, Global LAnd Surface Satellite (GLASS) LAI, Geoland2 version 1 (GEOV1) LAI, Global Inventory Monitoring and Modeling System (GIMMS) LAI, and Moderate Resolution Imaging Spectroradiometer (MODIS) LAI, were selected to examine the influences of LAI representation on GPP estimations at 95 eddy covariance (EC) sites. The GPP estimations from the Boreal Ecosystem Productivity Simulator (BEPS) model and the Eddy Covariance Light Use Efficiency (EC-LUE) model were evaluated against EC GPP to assess the performances of LAI datasets. Results showed that MODIS LAI had stronger linear correlations with GLASS and GEOV1 than GIMMS and GLOMAP at the study sites. The GPP estimations from GLASS LAI had a better agreement with EC GPP than those from other four LAI datasets at forest sites, while the GPP estimations from GEOVI LAI matched best with EC GPP at grass sites. Additionally, the GPP estimations from GLASS and GEOVI LAI presented better performances than the other three LAI datasets at crop sites. Besides, the results also showed that complex terrain had larger discrepancies of LAI and GPP estimations, and flat terrain presented better performances of LAI datasets in GPP estimations. Moreover, the simulated GPP from BEPS was more sensitive to LAI than those from EC - LUE, suggesting that LAI datasets can also lead to different uncertainties in GPP estimations from different model structures. Our study highlights that the satellite-derived LAI datasets can cause uncertainties in GPP estimations through ecosystem models.


Assuntos
Ecossistema , Monitoramento Ambiental , Imagens de Satélites , Florestas , Modelos Biológicos , Fotossíntese , Estações do Ano
17.
Sci Total Environ ; 690: 1254-1267, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31470488

RESUMO

Drought-induced forest dieback is causing reductions in productivity, increasing tree mortality and impairing terrestrial carbon uptake worldwide. However, the role played by long-term nutrient imbalances during drought-induced dieback is still unknown. To improve our knowledge on the relationships between dieback and nutrient imbalances, we analysed wood anatomical traits (tree-ring width and wood density), soil properties and long-term chemical information in tree-ring wood (1900-2010) by non-destructive Micro X-ray fluorescence (µXRF) and destructive (ICP-OES) techniques. We studied two major European conifers with ongoing drought-induced dieback in mesic (Abies alba, silver fir) and xeric (Pinus sylvestris, Scots pine) sites. In each site we compared coexisting declining (D) and non-declining (ND) trees. We used dendrochronology and generalized additive and linear mixed models to analyse trends in tree-ring nutrients and their relationships with wood traits. The D trees presented lower growth and higher minimum wood density than ND trees, corresponding to a smaller lumen area of earlywood tracheids and thus a lower theoretical hydraulic conductivity. These differences in growth and wood-anatomy were more marked in silver fir than in Scots pine. Moreover, most of the chemical elements showed higher concentrations in D than in ND trees during the last two-five decades (e.g., Mn, K and Mg), while Ca and Na increased in the sapwood of ND trees. The Mn concentrations, and related ratios (Ca:Mn, Mn:Al and P:Mn) showed the highest differences between D and ND trees for both tree species. These findings suggest that a reduced hydraulic conductivity, consistent with hydraulic impairment, is affecting the use of P in D trees, making them more prone to drought-induced damage. The retrospective quantifications of Mn ratios may be used as early-warning signals of impending dieback.


Assuntos
Secas , Monitoramento Ambiental , Florestas , Abies , Clima , Nitrogênio , Fósforo , Pinus sylvestris , Árvores
18.
An Acad Bras Cienc ; 91(3): e20180439, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31531531

RESUMO

The orchid seed banks of Atlantic Forest may be considered a key strategy for the conservation of species threatened with extinction by indiscriminate collection or habitat destruction. The aim of this study was to evaluate the seed viability, to choose the best culture medium for the asymbiotic germination and evaluate germination, after storage for different periods and temperatures for the Brazilian native orchids: Gomesa praetexta (Rchb.f.) M.W.Chase & N.H.Williams, Gomesa forbesii (Hook.) M.W.Chase & N.H.Williams, Gomesa recurva R.Br. and Grandiphyllum divaricatum (Lindl.) Docha Neto. Knudson C (KC), Murashige & Skoog (MS), half-strength MS (1/2 MS macro- and micro-nutrients) and Woody Plant Medium (WPM) culture media were tested for germination. The WPM culture medium was the best for asymbiotic germination of all species evaluated, with high germination percentages and improved seedling development. Seeds of G. divaricatum, G. praetexta, G. recurva and G. forbesii indicated orthodox behavior, with high viability rates after 12 months of storage, being recommended the storage temperature of -80°C for the first three species and -20°C for G. forbesii. The protocol developed in the present study was efficient for seed bank storage, in vitro germination and seedling production of G. divaricatum and G. praetexta, contributing to conservation strategies of these species.


Assuntos
Técnicas de Cultura/métodos , Germinação/fisiologia , Orchidaceae/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Aclimatação , Brasil , Meios de Cultura , Espécies em Perigo de Extinção , Florestas , Orchidaceae/classificação , Banco de Sementes
19.
Oecologia ; 191(2): 475-482, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31485850

RESUMO

Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants play crucial roles in ecosystem functioning, and a key question is how time since abandonment and elevation (and inherent temperature gradients therein) affect patterns of ant recovery within secondary forest systems. Focusing on the Colombian Andes across a 1300 m altitudinal gradient and secondary forest (2-30 years) recovering on abandoned cattle pastures, we find that over time ant community composition and species richness recovered towards that of primary forest. However, these relationships are strongly dependent on elevation with the more open and warmer pasturelands supporting more ants than either primary or secondary forest at a particular elevation. The loss of species richness and change in species composition with elevation is less severe in pasture than forests, suggesting that conditions within pasture and its remaining scattered trees, hedgerows and forest fragments, are more favourable for some species, which are likely in or near thermal debt. Promoting and protecting natural regenerating forests over the long term in the montane tropics will likely offer significant potential for returning ant communities towards primary forest levels.


Assuntos
Formigas , Agricultura , Animais , Bovinos , Ecossistema , Florestas , Árvores
20.
BMC Ecol ; 19(1): 37, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31510990

RESUMO

BACKGROUND: Maintenance of biodiversity is an integral part of sustainable forest management. Epiphytic bryophytes are an important element of biodiversity. Thus, this work aims to study the role of different physical and biochemical factors in affecting the growth and proliferation of epiphytic liverworts. Fifty trees in three different plots, distributed in Senchal wildlife sanctuary, Darjeeling, were surveyed. Factors such as light intensity, moisture, and diameter at breast height (DBH) of the tree were studied to evaluate their possible role in affecting epiphytic liverworts. The effect of bark biochemical characteristics on the abundance of epiphytic liverworts was also studied by undertaking a quantitative test of pH, phenol, flavonoid, ortho-dihydric phenol, terpene, total sugar, and tannin. Multiple regression analysis and principal component analysis (PCA) were carried out to test the effects of these parameters. RESULTS: Light intensity, moisture, and DBH highly influenced the abundance of liverworts. Old trees had higher epiphytic liverwort cover than younger ones. Bark biochemical properties like pH, phenol, flavonoid, ortho-dihydric phenol, tannin and sugar did not have a significant effect on the epiphytic liverwort cover, while the terpenoid content of the bark reduced liverworts cover. CONCLUSION: To sustain the occurrence of epiphytic liverworts in ecosystems, forest management should ensure the presence of old trees. Light intensity and moisture had a large effect on the distribution and abundance of liverworts, so it is important to maintain tree cover, shrub layer, and tree density.


Assuntos
Cryptomeria , Hepatófitas , Animais , Ecossistema , Casca de Planta , Árvores
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