Digital photography for assessing vegetation phenology in two contrasting northern ecosystems

Abstract. Digital repeat photography has become a widely used tool for assessing the annual course of vegetation phenology of different ecosystems. A greenness measure derived from digital images potentially provides an inexpensive and powerful means to analyze the annual cycle of ecosystem phenology. By using the Green Chromatic Coordinate (GCC), we examined the feasibility of digital repeat photography for assessing the vegetation phenology in two contrasting high-latitude ecosystems. While the seasonal changes in GCC are more obvious for the ecosystem that is dominated by annual plants (open wetland), clear seasonal patterns were also observed for the evergreen ecosystem (coniferous forest). Limited solar radiation restricts the use of images during the night and in wintertime, for which time windows were determined based on images of a grey reference plate. The variability in cloudiness had only a minor effect on GCC, and GCC did not depend on the sun angle and direction either. The GCC of wetland developed in tandem with the daily photosynthetic capacity estimated from the atmosphere-ecosystem flux measurements. At the forest site, the seasonal GCC cycle correlated well with the flux data in 2015 but there were some temporary deviations in 2014. The year-to-year differences were most likely generated by meteorological conditions, especially the differences in temperature. In addition to depicting the seasonal course of ecosystem functioning, GCC was shown to respond to physiological changes on a daily time scale. It seems that our northern sites, with a short and pronounced growing season, suit especially well for the monitoring of phenological variations with digital images.

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Digital photography for assessing the link between vegetation phenology and CO<sub>2</sub> exchange in two contrasting northern ecosystems

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-5-417-2016 ◽

2016 ◽

Vol 5 (2) ◽

pp. 417-426 ◽

Cited By ~ 13

Author(s):

Maiju Linkosalmi ◽

Mika Aurela ◽

Juha-Pekka Tuovinen ◽

Mikko Peltoniemi ◽

Cemal M. Tanis ◽

...

Keyword(s):

Environmental Changes ◽

Gross Primary Production ◽

Coniferous Forest ◽

Co2 Flux ◽

Minor Effect ◽

Forest Site ◽

Vegetation Phenology ◽

Repeat Photography ◽

A Minor ◽

Digital Repeat Photography

Abstract. Digital repeat photography has become a widely used tool for assessing the annual course of vegetation phenology of different ecosystems. By using the green chromatic coordinate (GCC) as a greenness measure, we examined the feasibility of digital repeat photography for assessing the vegetation phenology in two contrasting high-latitude ecosystems. Ecosystem–atmosphere CO2 fluxes and various meteorological variables were continuously measured at both sites. While the seasonal changes in GCC were more obvious for the ecosystem that is dominated by annual plants (open wetland), clear seasonal patterns were also observed for the evergreen ecosystem (coniferous forest). Daily and seasonal time periods with sufficient solar radiation were determined based on images of a grey reference plate. The variability in cloudiness had only a minor effect on GCC, and GCC did not depend on the sun angle and direction either. The daily GCC of wetland correlated well with the daily photosynthetic capacity estimated from the CO2 flux measurements. At the forest site, the correlation was high in 2015 but there were discernible deviations during the course of the summer of 2014. The year-to-year differences were most likely generated by meteorological conditions, with higher temperatures coinciding with higher GCCs. In addition to depicting the seasonal course of ecosystem functioning, GCC was shown to respond to environmental changes on a timescale of days. Overall, monitoring of phenological variations with digital images provides a powerful tool for linking gross primary production and phenology.

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Reviews and syntheses: Australian vegetation phenology: new insights from satellite remote sensing and digital repeat photography

Biogeosciences ◽

10.5194/bg-13-5085-2016 ◽

2016 ◽

Vol 13 (17) ◽

pp. 5085-5102 ◽

Cited By ~ 39

Author(s):

Caitlin E. Moore ◽

Tim Brown ◽

Trevor F. Keenan ◽

Remko A. Duursma ◽

Albert I. J. M. van Dijk ◽

...

Keyword(s):

Remote Sensing ◽

Satellite Remote Sensing ◽

Tropical Rainforests ◽

Vegetation Phenology ◽

Repeat Photography ◽

Tropical Savannas ◽

Diverse Range ◽

Canopy Development ◽

Continental Scale ◽

Digital Repeat Photography

Abstract. Phenology is the study of periodic biological occurrences and can provide important insights into the influence of climatic variability and change on ecosystems. Understanding Australia's vegetation phenology is a challenge due to its diverse range of ecosystems, from savannas and tropical rainforests to temperate eucalypt woodlands, semi-arid scrublands, and alpine grasslands. These ecosystems exhibit marked differences in seasonal patterns of canopy development and plant life-cycle events, much of which deviates from the predictable seasonal phenological pulse of temperate deciduous and boreal biomes. Many Australian ecosystems are subject to irregular events (i.e. drought, flooding, cyclones, and fire) that can alter ecosystem composition, structure, and functioning just as much as seasonal change. We show how satellite remote sensing and ground-based digital repeat photography (i.e. phenocams) can be used to improve understanding of phenology in Australian ecosystems. First, we examine temporal variation in phenology on the continental scale using the enhanced vegetation index (EVI), calculated from MODerate resolution Imaging Spectroradiometer (MODIS) data. Spatial gradients are revealed, ranging from regions with pronounced seasonality in canopy development (i.e. tropical savannas) to regions where seasonal variation is minimal (i.e. tropical rainforests) or high but irregular (i.e. arid ecosystems). Next, we use time series colour information extracted from phenocam imagery to illustrate a range of phenological signals in four contrasting Australian ecosystems. These include greening and senescing events in tropical savannas and temperate eucalypt understorey, as well as strong seasonal dynamics of individual trees in a seemingly static evergreen rainforest. We also demonstrate how phenology links with ecosystem gross primary productivity (from eddy covariance) and discuss why these processes are linked in some ecosystems but not others. We conclude that phenocams have the potential to greatly improve the current understanding of Australian ecosystems. To facilitate the sharing of this information, we have formed the Australian Phenocam Network (http://phenocam.org.au/).

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Australian vegetation phenology: new insights from satellite remote sensing and digital repeat photography

10.5194/bg-2016-175-rc2 ◽

2016 ◽

Author(s):

Anonymous

Keyword(s):

Remote Sensing ◽

Satellite Remote Sensing ◽

Vegetation Phenology ◽

Repeat Photography ◽

Digital Repeat Photography

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Vegetation phenology can be captured with digital repeat photography and linked to variability of root nutrition inHedysarum alpinum

Applied Vegetation Science ◽

10.1111/avsc.12000 ◽

2012 ◽

Vol 16 (2) ◽

pp. 317-324 ◽

Cited By ~ 20

Author(s):

W. Nijland ◽

N.C. Coops ◽

S.C.P. Coogan ◽

C.W. Bater ◽

M.A. Wulder ◽

...

Keyword(s):

Vegetation Phenology ◽

Repeat Photography ◽

Digital Repeat Photography

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Using Digital Photography to Track Understory Phenology in Mediterranean Cork Oak Woodlands

Remote Sensing ◽

10.3390/rs13040776 ◽

2021 ◽

Vol 13 (4) ◽

pp. 776

Author(s):

Catarina Jorge ◽

João M. N. Silva ◽

Joana Boavida-Portugal ◽

Cristina Soares ◽

Sofia Cerasoli

Keyword(s):

Climatic Factors ◽

Cork Oak ◽

Understory Vegetation ◽

Coefficient Of Determination ◽

Maximum Temperature ◽

Vegetation Phenology ◽

Repeat Photography ◽

Shrub Species ◽

Oak Woodlands ◽

Digital Repeat Photography

Monitoring vegetation is extremely relevant in the context of climate change, and digital repeat photography is a method that has gained momentum due to a low cost–benefit ratio. This work aims to demonstrate the possibility of using digital cameras instead of field spectroradiometers (FS) to track understory vegetation phenology in Mediterranean cork oak woodlands. A commercial camera was used to take monthly photographs that were processed with the Phenopix package to extract green chromatic coordinates (GCC). GCC showed good agreement with the normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) obtained with FS data. The herbaceous layer displayed a very good fit between GCC and NDVI (coefficient of determination, represented by r2 = 0.89). On the contrary, the GCC of shrubs (Cistus salviifolius and Ulex airensis) showed a better fit with NDWI (r2 = 0.78 and 0.55, respectively) than with NDVI (r2 = 0.60 and 0.30). Models show that grouping shrub species together improves the predictive results obtained with ulex but not with cistus. Concerning the relationship with climatic factors, all vegetation types showed a response to rainfall and temperature. Grasses and cistus showed similar responses to meteorological drivers, particularly mean maximum temperature (r = −0.66 and −0.63, respectively). The use of digital repeat photography to track vegetation phenology was found to be very suitable for understory vegetation with the exception of one shrub species. Thus, this method proves to have the potential to monitor a wide spectrum of understory vegetation at a much lower cost than FS.

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Australian vegetation phenology: new insights from satellite remote sensing and digital repeat photography

10.5194/bg-2016-175 ◽

2016 ◽

Author(s):

Caitlin E. Moore ◽

Tim Brown ◽

Trevor F. Keenan ◽

Remko A. Duursma ◽

Albert I. J. M. van Dijk ◽

...

Keyword(s):

Remote Sensing ◽

Satellite Remote Sensing ◽

Tropical Rainforests ◽

Vegetation Phenology ◽

Repeat Photography ◽

Tropical Savannas ◽

Diverse Range ◽

Canopy Development ◽

Continental Scale ◽

Digital Repeat Photography

Abstract. Phenology is the study of periodic biological occurrences and can provide important insights into the influence of climatic variability and change on ecosystems. Understanding Australia’s vegetation phenology is a challenge due to its diverse range of ecosystems, from savannas and tropical rainforests to temperate eucalypt woodlands, semi-arid scrublands and alpine grasslands. These ecosystems exhibit marked differences in seasonal patterns of canopy development and plant life-cycle events, much of which deviates from the predictable seasonal phenological pulse of temperate deciduous and boreal biomes. Many Australian ecosystems are subject to irregular events (i.e., drought, flooding, cyclones and fire) that can alter ecosystem composition, structure and functioning just as much as seasonal change. We show how satellite remote sensing and ground-based digital repeat photography (i.e. phenocams) can be used to improve understanding of phenology in Australian ecosystems. First, we examine temporal variation in phenology at the continental scale using the Enhanced Vegetation Index (EVI), calculated from MODerate resolution Imaging Spectroradiomter (MODIS) data. Spatial gradients are revealed, ranging from regions with pronounced seasonality in canopy development (i.e., tropical savannas) to regions where seasonal variation is minimal (i.e., tropical rainforests) or high but irregular (i.e., arid ecosystems). Next, we use time series colour information extracted from phenocam imagery to illustrate a range of phenological signals in four contrasting Australian ecosystems. These include greening and senescing events in tropical savannas and temperate eucalypt understory, as well as strong seasonal dynamics of individual trees in a seemingly static evergreen rainforest. We also demonstrate how phenology links with ecosystem gross primary productivity (from eddy covariance) and discuss why these processes are linked in some ecosystems but not others. We conclude that phenocams have the potential to greatly improve current understanding of Australian ecosystems. To facilitate sharing of this information, we have formed the Australian Phenocam Network (http://phenocam.org.au/).

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Improvement of monitoring of tertiary filtration with particle counting

Water Science & Technology Water Supply ◽

10.2166/ws.2006.001 ◽

2006 ◽

Vol 6 (1) ◽

pp. 1-9

Author(s):

V. Miska ◽

J.H.J.M. van der Graaf ◽

J. de Koning

Keyword(s):

Particle Surface ◽

Minor Effect ◽

Particle Size Distributions ◽

Particle Volume ◽

Mass Distributions ◽

Particle Counting ◽

Total Particle ◽

Particle Counts ◽

A Minor ◽

Sample Dilution

Nowadays filtration processes are still monitored with conventional analyses like turbidity measurements and, in case of flocculation–filtration, with phosphorus analyses. Turbidity measurements have the disadvantage that breakthrough of small flocs cannot be displayed, because of the blindness regarding changes in the mass distributions. Additional particle volume distributions calculated from particle size distributions (PSDs) would provide a better assessment of filtration performance. Lab-scale experiments have been executed on a flocculation–filtration column fed with effluent from WWTP Beverwijk in The Netherlands. Besides particle counting at various sampling points, the effect of sample dilution on the accuracy of PSD measurements has been reflected. It was found that the dilution has a minor effect on PSD of low turbidity samples such as process filtrate. The correlation between total particle counts, total particle volume (TPV) and total particle surface is not high but is at least better for diluted measurements of particles in the range 2–10 μm. Furthermore, possible relations between floc-bound phosphorus and TPV removal had been investigated. A good correlation coefficient is found for TPV removal versus floc-bound phosphorus removal for the experiments with polyaluminiumchloride and the experiments with single denitrifying and blank filtration.

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Linkage mapping identifies a non-synonymous mutation in FLOWERING LOCUS T (FT-B1) increasing spikelet number per spike

Scientific Reports ◽

10.1038/s41598-020-80473-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jonathan Brassac ◽

Quddoos H. Muqaddasi ◽

Jörg Plieske ◽

Martin W. Ganal ◽

Marion S. Röder

Keyword(s):

Flowering Time ◽

Aspartic Acid ◽

Synonymous Substitution ◽

Minor Effect ◽

Phenotypic Variance ◽

Spikelet Number ◽

Wheat Varieties ◽

Trait Locus ◽

A Minor ◽

Spikelet Number Per Spike

AbstractTotal spikelet number per spike (TSN) is a major component of spike architecture in wheat (Triticumaestivum L.). A major and consistent quantitative trait locus (QTL) was discovered for TSN in a doubled haploid spring wheat population grown in the field over 4 years. The QTL on chromosome 7B explained up to 20.5% of phenotypic variance. In its physical interval (7B: 6.37–21.67 Mb), the gene FLOWERINGLOCUST (FT-B1) emerged as candidate for the observed effect. In one of the parental lines, FT-B1 carried a non-synonymous substitution on position 19 of the coding sequence. This mutation modifying an aspartic acid (D) into a histidine (H) occurred in a highly conserved position. The mutation was observed with a frequency of ca. 68% in a set of 135 hexaploid wheat varieties and landraces, while it was not found in other plant species. FT-B1 only showed a minor effect on heading and flowering time (FT) which were dominated by a major QTL on chromosome 5A caused by segregation of the vernalization gene VRN-A1. Individuals carrying the FT-B1 allele with amino acid histidine had, on average, a higher number of spikelets (15.1) than individuals with the aspartic acid allele (14.3) independent of their VRN-A1 allele. We show that the effect of TSN is not mainly related to flowering time; however, the duration of pre-anthesis phases may play a major role.

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IL-6 Is Not Absolutely Essential for the Development of a TH17 Immune Response after an Aerosol Infection with Mycobacterium tuberculosis H37rv

Cells ◽

10.3390/cells10010009 ◽

2020 ◽

Vol 10 (1) ◽

pp. 9

Author(s):

Kristina Ritter ◽

Jan Christian Sodenkamp ◽

Alexandra Hölscher ◽

Jochen Behrends ◽

Christoph Hölscher

Keyword(s):

Immune Response ◽

Inflammatory Diseases ◽

Mycobacterial Infection ◽

Minor Effect ◽

Mycobacterium Tuberculosis H37rv ◽

Th 17 ◽

Anti Inflammatory ◽

A Minor ◽

Aerosol Infection ◽

Deficient Mice

Anti-inflammatory treatment of chronic inflammatory diseases often increases susceptibility to infectious diseases such as tuberculosis (TB). Since numerous chronic inflammatory and autoimmune diseases are mediated by interleukin (IL)-6-induced T helper (TH) 17 cells, a TH17-directed anti-inflammatory therapy may be preferable to an IL-12-dependent TH1 inhibition in order to avoid reactivation of latent infections. To assess, however, the risk of inhibition of IL-6-dependent TH17-mediated inflammation, we examined the TH17 immune response and the course of experimental TB in IL-6- and T-cell-specific gp130-deficient mice. Our study revealed that the absence of IL-6 or gp130 on T cells has only a minor effect on the development of antigen-specific TH1 and TH17 cells. Importantly, these gene-deficient mice were as capable as wild type mice to control mycobacterial infection. Together, in contrast to its key function for TH17 development in other inflammatory diseases, IL-6 plays an inferior role for the generation of TH17 immune responses during experimental TB.

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Sweet taste of heavy water

Communications Biology ◽

10.1038/s42003-021-01964-y ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Natalie Ben Abu ◽

Philip E. Mason ◽

Hadar Klein ◽

Nitzan Dubovski ◽

Yaron Ben Shoshan-Galeczki ◽

...

Keyword(s):

Heavy Water ◽

Calcium Release ◽

Homology Modelling ◽

Taste Receptor ◽

Chemical Properties ◽

Sweet Taste ◽

Minor Effect ◽

Dynamics Simulations ◽

A Minor ◽

Physical And Chemical

AbstractHydrogen to deuterium isotopic substitution has only a minor effect on physical and chemical properties of water and, as such, is not supposed to influence its neutral taste. Here we conclusively demonstrate that humans are, nevertheless, able to distinguish D2O from H2O by taste. Indeed, highly purified heavy water has a distinctly sweeter taste than same-purity normal water and can add to perceived sweetness of sweeteners. In contrast, mice do not prefer D2O over H2O, indicating that they are not likely to perceive heavy water as sweet. HEK 293T cells transfected with the TAS1R2/TAS1R3 heterodimer and chimeric G-proteins are activated by D2O but not by H2O. Lactisole, which is a known sweetness inhibitor acting via the TAS1R3 monomer of the TAS1R2/TAS1R3, suppresses the sweetness of D2O in human sensory tests, as well as the calcium release elicited by D2O in sweet taste receptor-expressing cells. The present multifaceted experimental study, complemented by homology modelling and molecular dynamics simulations, resolves a long-standing controversy about the taste of heavy water, shows that its sweet taste is mediated by the human TAS1R2/TAS1R3 taste receptor, and opens way to future studies of the detailed mechanism of action.

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