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Duarte, Carlos M.; Thampanya, Udomluck; Terrados, Jorge; Geertz‐Hansen, Ole; Fortes, Miguel D.

doi:10.1023/a:1009967401337

Cited by 40 publications

(6 citation statements)

References 15 publications

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“…On August 16 th , 2013, three similarly sized seedlings of A. germinans with 5-9 stem nodes were collected from the PA-arid and PA-humid sites, separated by the Bragança-Ajuruteua road, and transplanted with the surrounding soil into 3.0-L pots (Figure 2c). Based on previous observations of other Avicennia species (Almahasheer, Duarte, & Irigoien, 2016; Duarte, Thampanya, Terrados, Geertz-Hansen, & Fortes, 1999), we estimate that all samples were between at least 3.5 months to at most 11 months old. For acclimation in a homogeneous environment, pots were placed in open-air and naturally shaded conditions and were watered daily after the sunset, with 300 mL of tap water.…”

Section: Methodsmentioning

confidence: 88%

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Cruz

Mori

et al. 2019

Preprint

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Environmental variation along the geographical space can shape populations by natural selection. In the context of global warming and changing precipitation regimes, it is crucial to understand the role of environmental heterogeneity in tropical trees adaptation, given their disproportional contribution to water and carbon biogeochemical cycles. Here, we investigated how heterogeneity in freshwater availability along tropical wetlands has influenced molecular variations of the black mangrove (Avicennia germinans). A total of 57 trees were sampled at seven sites differing markedly in precipitation regime and riverine freshwater inputs. Using 2,297 genome‐wide single nucleotide polymorphic markers, we found signatures of natural selection by the association between variations in allele frequencies and environmental variables, including the precipitation of the warmest quarter and the annual precipitation. Additionally, we found candidate loci for selection based on statistical deviations from neutral expectations of interpopulation differentiation. Most candidate loci within transcribed sequences were functionally associated with central aspects of drought tolerance or plant response to drought. Moreover, our results suggest the occurrence of the rapid evolution of a population, probably in response to sudden and persistent limitations in plant access to soil water, following a road construction in 1974. Observations supporting rapid evolution included the reduction in tree size and changes in allele frequencies and in transcript expression associated with increased drought tolerance through the accumulation of osmoprotectants and antioxidants, biosynthesis of cuticles, protection against protein degradation, stomatal closure, photorespiration and photosynthesis. We describe a major role of spatial heterogeneity in freshwater availability in the specialization of this typically tropical tree.

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Section: Methodsmentioning

confidence: 88%

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Cruz

Mori

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…humid sites, separated by the Bragança-Ajuruteua road, and transplanted with the surrounding soil into 3.0 L pots(Figure 2c). Based on previous observations of other Avicennia species(Almahasheer, Duarte, & Irigoien, 2016;Duarte, Thampanya, Terrados, Geertz- Hansen, & Fortes, 1999), we estimate that all samples were 3.5 to 11 months old. For acclimation in a homogeneous environment, pots were placed in open-air and naturally shaded conditions and…”

mentioning

confidence: 85%

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Cruz

Mori

et al. 2019

Molecular Ecology

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Environmental variation along the geographical space can shape populations by natural selection. In the context of global warming and changing precipitation regimes, it is crucial to understand the role of environmental heterogeneity in tropical trees adaptation, given their disproportional contribution to water and carbon biogeochemical cycles. Here, we investigated how heterogeneity in freshwater availability along tropical wetlands has influenced molecular variations of the black mangrove (Avicennia germinans). A total of 57 trees were sampled at seven sites differing markedly in precipitation regime and riverine freshwater inputs. Using 2,297 genome-wide single nucleotide polymorphic markers, we found signatures of natural selection by the association between variations in allele frequencies and environmental variables, including the precipitation of the warmest quarter and the annual precipitation. Additionally, we found candidate loci for selection based on statistical deviations from neutral expectations of interpopulation differentiation. Most candidate loci within transcribed sequences were functionally associated with central aspects of drought tolerance or plant response to drought. Moreover, our results suggest the occurrence of the rapid evolution of a population, probably in response to sudden and persistent limitations in plant access to soil water, following a road construction in 1974. Observations supporting rapid evolution included the reduction in tree size and changes in allele frequencies and in transcript expression associated with increased drought tolerance through the accumulation of osmoprotectants and antioxidants, biosynthesis of cuticles, protection against protein degradation, stomatal closure, photorespiration and photosynthesis. We describe a major role of spatial heterogeneity in freshwater availability in the specialization of this typically tropical tree. K E Y W O R D SAvicennia germinans (Black Mangrove), drought-tolerance, ecological genomics, nextRAD, RNA-Seq, tropical tree | 345 CRUZ et al.

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“…The core tasks of classifying mangrove extent, age, and species, and image fusion are explained in the following sub-sections. [44] and internodes [45]. However, few studies have attempted to define classifiers dealing with mangrove age estimations from remotely sensed data.…”

Section: Methodsmentioning

confidence: 99%

“…Mangrove age and growth estimations are typically quantified by means of in situ dendrometer techniques [44] and internodes [45]. However, few studies have attempted to define classifiers dealing with mangrove age estimations from remotely sensed data.…”

Section: Mangrove Age Classificationmentioning

confidence: 99%

Multi-Decadal Changes in Mangrove Extent, Age and Species in the Red River Estuaries of Viet Nam

et al. 2020

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This research investigated the performance of four different machine learning supervised image classifiers: artificial neural network (ANN), decision tree (DT), random forest (RF), and support vector machine (SVM) using SPOT-7 and Sentinel-1 images to classify mangrove age and species in 2019 in a Red River estuary, typical of others found in northern Viet Nam. The four classifiers were chosen because they are considered to have high accuracy, however, their use in mangrove age and species classifications has thus far been limited. A time-series of Landsat images from 1975 to 2019 was used to map mangrove extent changes using the unsupervised classification method of iterative self-organizing data analysis technique (ISODATA) and a comparison with accuracy of K-means classification, which found that mangrove extent has increased, despite a fall in the 1980s, indicating the success of mangrove plantation and forest protection efforts by local people in the study area. To evaluate the supervised image classifiers, 183 in situ training plots were assessed, 70% of them were used to train the supervised algorithms, with 30% of them employed to validate the results. In order to improve mangrove species separations, Gram–Schmidt and principal component analysis image fusion techniques were applied to generate better quality images. All supervised and unsupervised (2019) results of mangrove age, species, and extent were mapped and accuracy was evaluated. Confusion matrices were calculated showing that the classified layers agreed with the ground-truth data where most producer and user accuracies were greater than 80%. The overall accuracy and Kappa coefficients (around 0.9) indicated that the image classifications were very good. The test showed that SVM was the most accurate, followed by DT, ANN, and RF in this case study. The changes in mangrove extent identified in this study and the methods tested for using remotely sensed data will be valuable to monitoring and evaluation assessments of mangrove plantation projects.

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Cited by 40 publications

References 15 publications

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae)

Multi-Decadal Changes in Mangrove Extent, Age and Species in the Red River Estuaries of Viet Nam

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