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1.
Nat Commun ; 15(1): 1330, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38351066

RESUMO

Human factors and plant characteristics are important drivers of plant invasions, which threaten ecosystem integrity, biodiversity and human well-being. However, while previous studies often examined a limited number of factors or focused on a specific invasion stage (e.g., naturalization) for specific regions, a multi-factor and multi-stage analysis at the global scale is lacking. Here, we employ a multi-level framework to investigate the interplay between plant characteristics (genome size, Grime's adaptive CSR-strategies and native range size) and economic use and how these factors collectively affect plant naturalization and invasion success worldwide. While our findings derived from structural equation models highlight the substantial contribution of human assistance in both the naturalization and spread of invasive plants, we also uncovered the pivotal role of species' adaptive strategies among the factors studied, and the significantly varying influence of these factors across invasion stages. We further revealed that the effects of genome size on plant invasions were partially mediated by species adaptive strategies and native range size. Our study provides insights into the complex and dynamic process of plant invasions and identifies its key drivers worldwide.


Assuntos
Cidadania , Ecossistema , Humanos , Tamanho do Genoma , Espécies Introduzidas , Ecologia , Biodiversidade , Plantas/genética
2.
Nat Commun ; 15(1): 166, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167693

RESUMO

Trees are pivotal to global biodiversity and nature's contributions to people, yet accelerating global changes threaten global tree diversity, making accurate species extinction risk assessments necessary. To identify species that require expert-based re-evaluation, we assess exposure to change in six anthropogenic threats over the last two decades for 32,090 tree species. We estimated that over half (54.2%) of the assessed species have been exposed to increasing threats. Only 8.7% of these species are considered threatened by the IUCN Red List, whereas they include more than half of the Data Deficient species (57.8%). These findings suggest a substantial underestimation of threats and associated extinction risk for tree species in current assessments. We also map hotspots of tree species exposed to rapidly changing threats around the world. Our data-driven approach can strengthen the efforts going into expert-based IUCN Red List assessments by facilitating prioritization among species for re-evaluation, allowing for more efficient conservation efforts.


Assuntos
Espécies em Perigo de Extinção , Árvores , Biodiversidade , Conservação dos Recursos Naturais , Extinção Biológica
3.
Nat Commun ; 14(1): 6950, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907453

RESUMO

Across the globe, tree species are under high anthropogenic pressure. Risks of extinction are notably more severe for species with restricted ranges and distinct evolutionary histories. Here, we use a global dataset covering 41,835 species (65.1% of known tree species) to assess the spatial pattern of tree species' phylogenetic endemism, its macroecological drivers, and how future pressures may affect the conservation status of the identified hotspots. We found that low-to-mid latitudes host most endemism hotspots, with current climate being the strongest driver, and climatic stability across thousands to millions of years back in time as a major co-determinant. These hotspots are mostly located outside of protected areas and face relatively high land-use change and future climate change pressure. Our study highlights the risk from climate change for tree diversity and the necessity to strengthen conservation and restoration actions in global hotspots of phylogenetic endemism for trees to avoid major future losses of tree diversity.


Assuntos
Biodiversidade , Mudança Climática , Filogenia , Conservação dos Recursos Naturais , Evolução Biológica , Ecossistema
4.
Ecol Evol ; 13(11): e10747, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38020673

RESUMO

How to effectively obtain species-related low-dimensional data from massive environmental variables has become an urgent problem for species distribution models (SDMs). In this study, we will explore whether dimensionality reduction on environmental variables can improve the predictive performance of SDMs. We first used two linear (i.e., principal component analysis (PCA) and independent components analysis) and two nonlinear (i.e., kernel principal component analysis (KPCA) and uniform manifold approximation and projection) dimensionality reduction techniques (DRTs) to reduce the dimensionality of high-dimensional environmental data. Then, we established five SDMs based on the environmental variables of dimensionality reduction for 23 real plant species and nine virtual species, and compared the predictive performance of those with the SDMs based on the selected environmental variables through Pearson's correlation coefficient (PCC). In addition, we studied the effects of DRTs, model complexity, and sample size on the predictive performance of SDMs. The predictive performance of SDMs under DRTs other than KPCA is better than using PCC. And the predictive performance of SDMs using linear DRTs is better than using nonlinear DRTs. In addition, using DRTs to deal with environmental variables has no less impact on the predictive performance of SDMs than model complexity and sample size. When the model complexity is at the complex level, PCA can improve the predictive performance of SDMs the most by 2.55% compared with PCC. At the middle level of sample size, the PCA improved the predictive performance of SDMs by 2.68% compared with the PCC. Our study demonstrates that DRTs have a significant effect on the predictive performance of SDMs. Specifically, linear DRTs, especially PCA, are more effective at improving model predictive performance under relatively complex model complexity or large sample sizes.

5.
Nat Ecol Evol ; 7(10): 1620-1632, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37640766

RESUMO

Predicting drought-induced mortality (DIM) of woody plants remains a key research challenge under climate change. Here, we integrate information on the edaphoclimatic niches, phylogeny and hydraulic traits of species to model the hydraulic risk of woody plants globally. We combine these models with species distribution records to estimate the hydraulic risk faced by local woody plant species assemblages. Thus, we produce global maps of hydraulic risk and test for its relationship with observed DIM. Our results show that local assemblages modelled as having higher hydraulic risk present a higher probability of DIM. Metrics characterizing this hydraulic risk improve DIM predictions globally, relative to models accounting only for edaphoclimatic predictors or broad functional groupings. The methodology we present here allows mapping of functional trait distributions and elucidation of global macro-evolutionary and biogeographical patterns, improving our ability to predict potential global change impacts on vegetation.


Assuntos
Secas , Plantas , Mudança Climática , Fenótipo
6.
New Phytol ; 239(6): 2389-2403, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37438886

RESUMO

Karyological characteristics are among the traits underpinning the invasion success of vascular plants. Using 11 049 species, we tested the effects of genome size and ploidy levels on plant naturalization (species forming self-sustaining populations where they are not native) and invasion (naturalized species spreading rapidly and having environmental impact). The probability that a species naturalized anywhere in the world decreased with increasing monoploid genome size (DNA content of a single chromosome set). Naturalized or invasive species with intermediate monoploid genomes were reported from many regions, but those with either small or large genomes occurred in fewer regions. By contrast, large holoploid genome sizes (DNA content of the unreplicated gametic nucleus) constrained naturalization but favoured invasion. We suggest that a small genome is an advantage during naturalization, being linked to traits favouring adaptation to local conditions, but for invasive spread, traits associated with a large holoploid genome, where the impact of polyploidy may act, facilitate long-distance dispersal and competition with other species.


Assuntos
Ecossistema , Traqueófitas , Tamanho do Genoma , Cidadania , Ploidias , Espécies Introduzidas , DNA
7.
Sci Adv ; 9(14): eadd8553, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-37018407

RESUMO

As Earth's climate has varied strongly through geological time, studying the impacts of past climate change on biodiversity helps to understand the risks from future climate change. However, it remains unclear how paleoclimate shapes spatial variation in biodiversity. Here, we assessed the influence of Quaternary climate change on spatial dissimilarity in taxonomic, phylogenetic, and functional composition among neighboring 200-kilometer cells (beta-diversity) for angiosperm trees worldwide. We found that larger glacial-interglacial temperature change was strongly associated with lower spatial turnover (species replacements) and higher nestedness (richness changes) components of beta-diversity across all three biodiversity facets. Moreover, phylogenetic and functional turnover was lower and nestedness higher than random expectations based on taxonomic beta-diversity in regions that experienced large temperature change, reflecting phylogenetically and functionally selective processes in species replacement, extinction, and colonization during glacial-interglacial oscillations. Our results suggest that future human-driven climate change could cause local homogenization and reduction in taxonomic, phylogenetic, and functional diversity of angiosperm trees worldwide.


Assuntos
Magnoliopsida , Humanos , Filogenia , Mudança Climática , Biodiversidade
8.
Proc Natl Acad Sci U S A ; 119(25): e2026733119, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35709320

RESUMO

Safeguarding Earth's tree diversity is a conservation priority due to the importance of trees for biodiversity and ecosystem functions and services such as carbon sequestration. Here, we improve the foundation for effective conservation of global tree diversity by analyzing a recently developed database of tree species covering 46,752 species. We quantify range protection and anthropogenic pressures for each species and develop conservation priorities across taxonomic, phylogenetic, and functional diversity dimensions. We also assess the effectiveness of several influential proposed conservation prioritization frameworks to protect the top 17% and top 50% of tree priority areas. We find that an average of 50.2% of a tree species' range occurs in 110-km grid cells without any protected areas (PAs), with 6,377 small-range tree species fully unprotected, and that 83% of tree species experience nonnegligible human pressure across their range on average. Protecting high-priority areas for the top 17% and 50% priority thresholds would increase the average protected proportion of each tree species' range to 65.5% and 82.6%, respectively, leaving many fewer species (2,151 and 2,010) completely unprotected. The priority areas identified for trees match well to the Global 200 Ecoregions framework, revealing that priority areas for trees would in large part also optimize protection for terrestrial biodiversity overall. Based on range estimates for >46,000 tree species, our findings show that a large proportion of tree species receive limited protection by current PAs and are under substantial human pressure. Improved protection of biodiversity overall would also strongly benefit global tree diversity.


Assuntos
Efeitos Antropogênicos , Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Árvores , Conservação dos Recursos Naturais/métodos , Humanos , Filogenia , Árvores/classificação
9.
Ecol Evol ; 11(2): 887-899, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33520173

RESUMO

High-mountain areas such as the Tibeto-Himalayan region (THR) host cold-adapted biota expected to be sensitive to anthropogenic climate change. Meconopsis is a representative endangered genus confined to alpine meadow or subnival habitats in the THR. We used climate-niche factor analysis to study the vulnerability of ten Meconopsis species to climate change, comparing current climate (representative of 1960-1990) to future climate scenarios (2070: average 2061-2080). For these ten Meconopsis species, we then identified potential future climate refugia and determined optimal routes for each species to disperse to the proposed refugia. Our results indicate that for the ten Meconopsis species, the regions with low vulnerability to climate change in the THR are the central Qinghai-Tibet Plateau, the Hengduan Mountains (HDM), the eastern Himalayas, and the West Qinling Mountain (WQL), and can be considered potential future climate refugia. Under future climate change, we found for the ten Meconopsis species potential dispersal routes to three of the four identified refugia: the HDM, the eastern Himalayas, and the WQL. Our results suggest that past refugia on the THR will also be the future climate refugia for the ten Meconopsis species, and these species may potentially persist in multiple future climate refugia, likely reducing risks from climate change. Furthermore, climate change may affect the threat ranking of Red Listed Species for Meconopsis species, as Least Concern species were estimated to become more vulnerable to climate change than the only Near Threatened species.

10.
Sci Rep ; 10(1): 17645, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077795

RESUMO

Estuaries are dynamic and selective environments that provide frequent opportunities for the turnover of Phragmites australis populations. We studied Phragmites genetic diversity patterns in three of the major deltas of China, viz. the Yellow River, the Yangtze and the Liaohe, in relation to Phragmites global phylogeography and soil salinity. We found that two distantly related P. australis haplotypes, each with intercontinental distribution, co-occur in these deltas in China. One is European Phragmites (Haplotype O) and is related to P. japonicus; the other (Haplotype P) has its range in East Asia and Australia and is related to the Asian tropical species P. karka. The two haplotypes have differing salt tolerance, with Haplotype O in areas with the highest salinity and Haplotype P in areas with the lowest. Introgressed hybrids of Haplotype P with P. karka, and F1 hybrids with Haplotype O, have higher salt tolerance than Haplotype P. Phylogenetic diversity appears as the factor that better explains population structure and salinity tolerance in these estuaries. Future research may explain whether the two P. australis haplotypes evolved in East Asia, and East Asia is a center of Phragmites diversity, or are introduced and a threat to P. japonicus and P. karka.


Assuntos
Poaceae/genética , Plantas Tolerantes a Sal/genética , China , Estuários , Variação Genética/genética , Haplótipos/genética , Repetições de Microssatélites/genética , Filogenia , Poaceae/fisiologia , Tolerância ao Sal/genética
11.
Sci Total Environ ; 664: 1150-1161, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30901787

RESUMO

Tall wetland graminoids with rapid growth, high productivity and wide tolerance of biotic and abiotic stresses are potentially valuable bioenergy crops, especially when grown in rewetted peat soils for biomass (paludiculture). Using wetland plants as renewable bioenergy crops instead of fossil fuels has the ecological benefits of reducing greenhouse gas (GHG) emissions, improving water quality and conserving peat soils. As these potential crops will grow in peat that differs in nutrient availability, not only will their biomass productivity be affected, but also the biomass quality for bioenergy may be altered. We set up five different nutrient availability treatments in waterlogged peat soil to simulate different nutrient environments for wetland plant cultivation. Seven wetland plants suitable for paludiculture (Typha latifolia, Arundo plinii, Arundo donax and four distinct genotypes of Phragmites australis from Denmark, The Netherlands, Romania and Italy) were selected to test responses of biomass production and tissue quality to different nutrient availability. Due to their high biomass productivity, T. latifolia, A. donax, Dutch (NL) and Romanian (RO) P. australis had the greatest potential to produce bioenergy feedstock. All taxa survived when cultivated with very low nutrient availability, especially NL and RO P. australis and T. latifolia. Moreover, biomass quality was both species-specific and element-specific, affected by increasing nutrient availability. Overall, T. latifolia had the lowest tissue concentrations of S and Si as well as high concentrations of Ca, and therefore the best tissue quality for combustion both at low and high nutrient availability. These results will provide crucial information for choosing appropriate crops and managements and promote the success of culturing wetland plants as bioenergy feedstock.


Assuntos
Poaceae/fisiologia , Typhaceae/fisiologia , Eliminação de Resíduos Líquidos , Áreas Alagadas , Biomassa , Nutrientes/metabolismo , Poaceae/crescimento & desenvolvimento , Typhaceae/crescimento & desenvolvimento , Poluentes Químicos da Água
12.
Ecol Lett ; 21(9): 1380-1389, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29974602

RESUMO

Determining the factors associated with the naturalization of alien species is a central theme in ecology. Here, we tested the usefulness of a metric for quantifying Grime's seminal concept of adaptive strategies - competitors, stress-tolerators and ruderals (CSR) - to explain plant naturalizations worldwide. Using a global dataset of 3004 vascular plant species, and accounting for phylogenetic relatedness and species' native biomes, we assessed the associations between calculated C-, S- and R-scores and naturalization success for species exhibiting different life forms. Across different plant life forms, C-scores were positively and S-scores negatively associated with both the probability of naturalization and the number of regions where the species has naturalized. R-scores had positive effects on the probability of naturalization. These effects of the scores were, however, weak to absent for tree species. Our findings demonstrate the utility of CSR-score calculation to broadly represent, and potentially explain, the naturalization success of plant species.


Assuntos
Ecossistema , Plantas , Ecologia , Filogenia
13.
Ecol Evol ; 8(5): 2440-2452, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29531666

RESUMO

Identifying the factors that influence spatial genetic structure among populations can provide insights into the evolution of invasive plants. In this study, we used the common reed (Phragmites australis), a grass native in Europe and invading North America, to examine the relative importance of geographic, environmental (represented by climate here), and human effects on population genetic structure and its changes during invasion. We collected samples of P. australis from both the invaded North American and native European ranges and used molecular markers to investigate the population genetic structure within and between ranges. We used path analysis to identify the contributions of each of the three factors-geographic, environmental, and human-related-to the formation of spatial genetic patterns. Genetic differentiation was observed between the introduced and native populations, and their genetic structure in the native and introduced ranges was different. There were strong effects of geography and environment on the genetic structure of populations in the native range, but the human-related factors manifested through colonization of anthropogenic habitats in the introduced range counteracted the effects of environment. The between-range genetic differences among populations were mainly explained by the heterogeneous environment between the ranges, with the coefficient 2.6 times higher for the environment than that explained by the geographic distance. Human activities were the primary contributor to the genetic structure of the introduced populations. The significant environmental divergence between ranges and the strong contribution of human activities to the genetic structure in the introduced range suggest that invasive populations of P. australis have evolved to adapt to a different climate and to human-made habitats in North America.

14.
Ecology ; 99(1): 79-90, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29313970

RESUMO

The literature suggests that small genomes promote invasion in plants, but little is known about the interaction of genome size with other traits or about the role of genome size during different phases of the invasion process. By intercontinental comparison of native and invasive populations of the common reed Phragmites australis, we revealed a distinct relationship between genome size and invasiveness at the intraspecific level. Monoploid genome size was the only significant variable that clearly separated the North American native plants from those of European origin. The mean Cx value (the amount of DNA in one chromosome set) for source European native populations was 0.490 ± 0.007 (mean ± SD), for North American invasive 0.506 ± 0.020, and for North American native 0.543 ± 0.021. Relative to native populations, the European populations that successfully invaded North America had a smaller genome that was associated with plant traits favoring invasiveness (long rhizomes, early emerging abundant shoots, resistance to aphid attack, and low C:N ratio). The knowledge that invasive populations within species can be identified based on genome size can be applied to screen potentially invasive populations of Phragmites in other parts of the world where they could grow in mixed stands with native plants, as well as to other plant species with intraspecific variation in invasion potential. Moreover, as small genomes are better equipped to respond to extreme environmental conditions such as drought, the mechanism reported here may represent an emerging driver for future invasions and range expansions.


Assuntos
Afídeos , Poaceae/genética , Animais , Espécies Introduzidas , América do Norte , Fenótipo , Plantas
15.
Front Plant Sci ; 8: 1833, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29250081

RESUMO

Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1) P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in climatic conditions such as temperature or atmospheric CO2; (2) each lineage consists of populations that may occur in geographically different habitats and contain multiple genotypes; (3) the phenotypic plasticity of functional and fitness-related traits of a genotype determine the responses to global change factors; (4) genotypes with high plasticity to environmental drivers may acclimate or even vastly expand their ranges, genotypes of medium plasticity must acclimate or experience range-shifts, and those with low plasticity may face local extinction; (5) responses to ancillary types of global change, like shifting levels of soil salinity, flooding, and drought, are not consistent within lineages and depend on adaptation of individual genotypes. These patterns suggest that the diverse lineages of P. australis will undergo intense selective pressure in the face of global change such that the distributions and interactions of co-occurring lineages, as well as those of genotypes within-lineages, are very likely to be altered. We propose that the strong latitudinal clines within and between P. australis lineages can be a useful tool for predicting plant responses to climate change in general and present a conceptual framework for using P. australis lineages to predict plant responses to global change and its consequences.

16.
Ecol Evol ; 4(24): 4567-77, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25558352

RESUMO

Compared with non-invasive species, invasive plant species may benefit from certain advantageous traits, for example, higher photosynthesis capacity and resource/energy-use efficiency. These traits can be preadapted prior to introduction, but can also be acquired through evolution following introduction to the new range. Disentangling the origins of these advantageous traits is a fundamental and emerging question in invasion ecology. We conducted a multiple comparative experiment under identical environmental condition with the invasive haplotype M lineage of the wetland grass Phragmites australis and compared the ecophysiological traits of this invasive haplotype M in North America with those of the European ancestor and the conspecific North American native haplotype E lineage, P. australis ssp. americanus. The invasive haplotype M differed significantly from the native North American conspecific haplotype E in several ecophysiological and morphological traits, and the European haplotype M had a more efficient photosynthetic apparatus than the native North American P. australis ssp. americanus. Within the haplotype M lineage, the introduced North American P. australis exhibited different biomass allocation patterns and resource/energy-use strategies compared to its European ancestor group. A discriminant analysis of principal components separated the haplotype M and the haplotype E lineages completely along the first canonical axis, highly related to photosynthetic gas-exchange parameters, photosynthetic energy-use efficiency and payback time. The second canonical axis, highly related to photosynthetic nitrogen use efficiency and construction costs, significantly separated the introduced P. australis in North America from its European ancestor. Synthesis. We conclude that the European P. australis lineage was preadapted to be invasive prior to its introduction, and that the invasion in North America is further stimulated by rapid post-introduction evolution in several advantageous traits. The multicomparison approach used in this study could be an effective approach for distinguishing preadaptation and post-introduction evolution of invasive species. Further research is needed to link the observed changes in invasive traits to the genetic variation and the interaction with the environment.

17.
Glob Chang Biol ; 19(11): 3406-22, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23765641

RESUMO

After its introduction into North America, Euro-Asian Phragmites australis became an aggressive invasive wetland grass along the Atlantic coast of North America. Its distribution range has since expanded to the middle, south and southwest of North America, where invasive P. australis has replaced millions of hectares of native plants in inland and tidal wetlands. Another P. australis invasion from the Mediterranean region is simultaneously occurring in the Gulf region of the United States and some countries in South America. Here, we analysed the occurrence records of the two Old World invasive lineages of P. australis (Haplotype M and Med) in both their native and introduced ranges using environmental niche models (ENMs) to assess (i) whether a niche shift accompanied the invasions in the New World; (ii) the role of biologically relevant climatic variables and human influence in the process of invasion; and (iii) the current potential distribution of these two lineages. We detected local niche shifts along the East Coast of North America and the Gulf Coast of the United States for Haplotype M and around the Mississippi Delta and Florida of the United States for Med. The new niche of the introduced Haplotype M accounts for temperature fluctuations and increased precipitation. The introduced Med lineage has enlarged its original subtropical niche to the tropics-subtropics, invading regions with a high annual mean temperature (> ca. 10 °C) and high precipitation in the driest period. Human influence is an important factor for both niches. We suggest that an increase in precipitation in the 20th century, global warming and human-made habitats have shaped the invasive niches of the two lineages in the New World. However, as the invasions are ongoing and human and natural disturbances occur concomitantly, the future distribution ranges of the two lineages may diverge from the potential distribution ranges detected in this study.


Assuntos
Ecossistema , Espécies Introduzidas , Poaceae , DNA de Cloroplastos/genética , Haplótipos , Atividades Humanas , Humanos , Modelos Teóricos , Poaceae/genética , Chuva , Análise de Sequência de DNA , Temperatura , Estados Unidos
18.
Ying Yong Sheng Tai Xue Bao ; 24(8): 2129-34, 2013 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-24380329

RESUMO

By the methods of field survey and laboratory analysis, an investigation was conducted on the seasonal dynamics of biomass and carbon storage of Phragmites australis and Spartina alterniflora dominated vegetation belts in the Jiuduan Shoal Wetland of Yangtze Estuary, East China in 2010-2012. The organic carbon storage of the biomass (including aboveground part, underground part, and standing litter) of the two plants was the highest in autumn and the lowest in spring. The average carbon storage of the biomass of S. alterniflora per unit area (445.81 g x m(-2)) was much higher than that of P. australis (285.52 g x m(-2)), and the average carbon storage of the standing litter of S. alterniflora (315.28 g x m(-2)) was also higher than that of P. australia (203.15 g x m(-2)). However, the organic carbon storage in the surface soil (0-30 cm) under P. australis community (1048.62 g x m(-2)) was almost as twice times as that under S. alterniflora community (583.33 g x m(-2)). Overall, the carbon accumulation ability of P. australis community (3212.96 g x m(-2)) was stronger than that of the S. alterniflora community (2730.42 g x m(-2)). Therefore, it is of significance to protect the P. australis community in terms of carbon sequestration at the salt marsh.


Assuntos
Sequestro de Carbono , Poaceae/crescimento & desenvolvimento , Áreas Alagadas , Biomassa , Carbono/metabolismo , China , Estuários , Rios
19.
Ying Yong Sheng Tai Xue Bao ; 22(9): 2383-90, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22126052

RESUMO

Based on the 1 m x 1 m high resolution aerial images in 2007 and the 30 m x 30 m Landsat 5 TM images in summer 2007, and with the help of GIS and remote sensing image interpretation, this paper calculated the normalized difference vegetation indices (NDVI) representing the overall ecological benefits of greening as well as the six controlling factors, i.e., multilayer structure height, area ratio of softness to hardness, greening rate, floor area ratio, greening area, and building density, in 30 typical urban residential quarters of west Hangzhou. The contributions of the controlling factors to the ecological benefits of greening as well as the quantitative relationships between the overall ecological benefits and the six controlling factors were analyzed by multiple linear regression and correspondence analysis, and some advises were given for the improvement of the ecological benefits. The contribution rate of the six factors was in the order of multilayer structure height > area ratio of softness to hardness > greening rate > floor area ratio > greening area > building density, and the contribution of multilayer structure height was far greater than that of the others whereas building density had the weakest effect on the ecological benefits. Correspondence analysis was effective in simplifying a complex data table into an intuitive two-dimensional chart, and thus, a potential powerful tool in decision-making for the improvement of ecological benefits of greening in urban residential quarters.


Assuntos
Planejamento de Cidades , Ecossistema , Planejamento Ambiental , Desenvolvimento Vegetal , China , Cidades , Sistemas de Informação Geográfica , Tecnologia de Sensoriamento Remoto
20.
Ying Yong Sheng Tai Xue Bao ; 22(9): 2391-8, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22126053

RESUMO

Based on the TM images, social-economic data, and field investigation data in 1990, 2000, and 2009, and by adopting redundancy analysis (RDA) and principal component analysis (PCA), this paper analyzed the contribution rates of landscape driving forces in coastal area of Fengxian reclamation zone at Yangtze Estuary. Kappa index was used to validate the simulation effectiveness of CLUE-S model. In the study area, anthropogenic landscape driving factors had a higher contribution rate than natural landscape driving factors (57.1% vs. 42.9%). The prediction accuracy rate of CLUE-S model was above 82%, the Kappa index of the main landscape types (farm land, unutilized land, and breeding ponds) was greater than 0.75, the simulation results were acceptable, and the landscape driving forces selected could better simulate the spatial distribution patterns of the abrupt transformation of the main landscape types.


Assuntos
Aquicultura , Conservação dos Recursos Naturais/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Modelos Teóricos , China , Monitoramento Ambiental , Oceanos e Mares , Fatores Socioeconômicos
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