7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. 319.56-11 Section 319.56-11 Agriculture Regulations of the Department of..., vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and...

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. 319.56-11 Section 319.56-11 Agriculture Regulations of the Department of..., vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and...

Effects of industrial processing on folate content in green vegetables.

PubMed

Delchier, Nicolas; Ringling, Christiane; Le Grandois, Julie; Aoudé-Werner, Dalal; Galland, Rachel; Georgé, Stéphane; Rychlik, Michael; Renard, Catherine M G C

2013-08-15

Folates are described to be sensitive to different physical parameters such as heat, light, pH and leaching. Most studies on folates degradation during processing or cooking treatments were carried out on model solutions or vegetables only with thermal treatments. Our aim was to identify which steps were involved in folates loss in industrial processing chains, and which mechanisms were underlying these losses. For this, the folates contents were monitored along an industrial canning chain of green beans and along an industrial freezing chain of spinach. Folates contents decreased significantly by 25% during the washing step for spinach in the freezing process, and by 30% in the green beans canning process after sterilisation, with 20% of the initial amount being transferred into the covering liquid. The main mechanism involved in folate loss during both canning green beans and freezing spinach was leaching. Limiting the contact between vegetables and water or using steaming seems to be an adequate measure to limit folates losses during processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

EFFECTS OF GEOMORPHIC PROCESSES AND HYDROLOGIC REGIMES ON RIPARIAN VEGETATION

EPA Science Inventory

In this chapter, the relationships among riparian vegetation and geomorphic and hydrologic processes in central Great Basin watersheds are evaluated over a range of scales. These relationships are examined through a series of case studies that have been conducted by the Great Ba...

An ecological vegetation-activated sludge process (V-ASP) for decentralized wastewater treatment: system development, treatment performance, and mathematical modeling.

PubMed

Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Li, Pu; Zhao, Ke

2016-05-01

An environment-friendly decentralized wastewater treatment process that is comprised of activated sludge process (ASP) and wetland vegetation, named as vegetation-activated sludge process (V-ASP), was developed for decentralized wastewater treatment. The long-term experimental results evidenced that the vegetation sequencing batch reactor (V-SBR) process had consistently stable higher removal efficiencies of organic substances and nutrients from domestic wastewater compared with traditional sequencing batch reactor (SBR). The vegetation allocated into V-SBR system could not only remove nutrients through its vegetation transpiration ratio but also provide great surface area for microorganism activity enhancement. This high vegetation transpiration ratio enhanced nutrients removal effectiveness from wastewater mainly by flux enhancement, oxygen and substrate transportation acceleration, and vegetation respiration stimulation. A mathematical model based on ASM2d was successfully established by involving the specific function of vegetation to simulate system performance. The simulation results on the influence of operational parameters on V-ASP treatment effectiveness demonstrated that V-SBR had a high resistance to seasonal temperature fluctuations and influent loading shocking.

Optimization of biodiesel production process using recycled vegetable oil

NASA Astrophysics Data System (ADS)

Lugo, Yarely

Petro diesel toxic emissions and its limited resources have created an interest for the development of new energy resources, such as biodiesel. Biodiesel is traditionally produced by a transesterification reaction between vegetable oil and an alcohol in the presence of a catalyst. However, this process is slow and expensive due to the high cost of raw materials. Low costs feedstock oils such as recycled and animal fats are available but they cannot be transesterified with alkaline catalysts due to high content of free fatty acids, which can lead to undesirable reactions such as saponification. In this study, we reduce free fatty acids content by using an acid pre-treatment. We compare sulfuric acid, hydrochloric acid and ptoluenesulfonic acid (PTSA) to pre-treat recycled vegetable oil. PTSA removes water after 60 minutes of treatment at room temperature or within 15 minutes at 50°C. The pretreatment was followed by a transesterification reaction using alkaline catalyst. To minimize costs and accelerate reaction, the pretreatment and transesterification reaction of recycle vegetable oil was conducted at atmospheric pressure in a microwave oven. Biodiesel was characterized using a GC-MS method.

Synergies of carvacrol and 1,8-cineole to inhibit bacteria associated with minimally processed vegetables.

PubMed

de Sousa, Jossana Pereira; de Azerêdo, Geíza Alves; de Araújo Torres, Rayanne; da Silva Vasconcelos, Margarida Angélica; da Conceição, Maria Lúcia; de Souza, Evandro Leite

2012-03-15

This study assessed the occurrence of an enhancing inhibitory effect of the combined application of carvacrol and 1,8-cineole against bacteria associated with minimally processed vegetables using the determination of Fractional Inhibitory Concentration (FIC) index, time-kill assay in vegetable broth and application in vegetable matrices. Their effects, individually and in combination, on the sensory characteristics of the vegetables were also determined. Carvacrol and 1,8-cineole displayed Minimum Inhibitory Concentration (MIC) in a range of 0.6-2.5 and 5-20 μL/mL, respectively, against the organisms studied. FIC indices of the combined application of the compounds were 0.25 against Listeria monocytogenes, Aeromonas hydrophila and Pseudomonas fluorescens, suggesting a synergic interaction. Application of carvacrol and 1,8-cineole alone (MIC) or in a mixture (1/8 MIC+1/8 MIC or 1/4 MIC+1/4 MIC) in vegetable broth caused a significant decrease (p<0.05) in bacterial count over 24h. Mixtures of carvacrol and 1,8-cineole reduced (p<0.05) the inocula of all bacteria in vegetable broth and in experimentally inoculated fresh-cut vegetables. A similar efficacy was observed in the reduction of naturally occurring microorganisms in vegetables. Sensory evaluation revealed that the scores of the most-evaluated attributes fell between "like slightly" and "neither like nor dislike." The combination of carvacrol and 1,8-cineole at sub-inhibitory concentrations could constitute an interesting approach to sanitizing minimally processed vegetables. Copyright © 2011 Elsevier B.V. All rights reserved.

Connectivity processes and riparian vegetation of the upper Paraná River, Brazil

NASA Astrophysics Data System (ADS)

Stevaux, José C.; Corradini, Fabrício A.; Aquino, Samia

2013-10-01

In fluvial systems, the relationship between a dominant variable (e.g. flood pulse) and its dependent ones (e.g. riparian vegetation) is called connectivity. This paper analyzes the connectivity elements and processes controlling riparian vegetation for a reach of the upper Paraná River (Brazil) and estimates the future changes in channel-vegetation relationship as a consequence of the managing of a large dam. The studied reach is situated 30 km downstream from the Porto Primavera Dam (construction finished in 1999). Through aerial photography (1:25,000, 1996), RGB-CBERS satellite imagery and a previous field botany survey it was possible to elaborate a map with the five major morpho-vegetation units: 1) Tree-dominated natural levee, 2) Shrubby upper floodplain, 3) Shrub-herbaceous mid floodplain, 4) Grass-herbaceous lower floodplain and 5) Shrub-herbaceous flood runoff channel units. By use of a detailed topographic survey and statistical tools each morpho-vegetation type was analyzed according to its connectivity parameters (frequency, recurrence, permanence, seasonality, potamophase, limnophase and FCQ index) in the pre- and post-dam closure periods of the historical series. Data showed that most of the morpho-vegetation units were predicted to present changes in connectivity parameters values after dam closing and the new regime could affect, in different intensity, the river ecology and particularly the riparian vegetation. The methods used in this study can be useful for dam impact studies in other South American tropical rivers.

21 CFR 133.170 - Pasteurized process cheese with fruits, vegetables, or meats.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Pasteurized process cheese with fruits, vegetables... AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.170 Pasteurized process cheese with...

21 CFR 133.170 - Pasteurized process cheese with fruits, vegetables, or meats.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Pasteurized process cheese with fruits, vegetables... AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.170 Pasteurized process cheese with...

Click chemistry approach to conventional vegetable tanning process: accelerated method with improved organoleptic properties.

PubMed

Krishnamoorthy, Ganesan; Ramamurthy, Govindaswamy; Sadulla, Sayeed; Sastry, Thotapalli Parvathaleswara; Mandal, Asit Baran

2014-09-01

Click chemistry approaches are tailored to generate molecular building blocks quickly and reliably by joining small units together selectively and covalently, stably and irreversibly. The vegetable tannins such as hydrolyzable and condensed tannins are capable to produce rather stable radicals or inhibit the progress of radicals and are prone to oxidations such as photo and auto-oxidation, and their anti-oxidant nature is well known. A lot remains to be done to understand the extent of the variation of leather stability, color variation (lightening and darkening reaction of leather), and poor resistance to water uptake for prolonged periods. In the present study, we have reported click chemistry approaches to accelerated vegetable tanning processes based on periodates catalyzed formation of oxidized hydrolysable and condensed tannins for high exhaustion with improved properties. The distribution of oxidized vegetable tannin, the thermal stability such as shrinkage temperature (T s) and denaturation temperature (T d), resistance to collagenolytic activities, and organoleptic properties of tanned leather as well as the evaluations of eco-friendly characteristics were investigated. Scanning electron microscopic analysis indicates the cross section of tightness of the leather. Differential scanning calorimetric analysis shows that the T d of leather is more than that of vegetable tanned or equal to aldehyde tanned one. The leathers exhibited fullness, softness, good color, and general appearance when compared to non-oxidized vegetable tannin. The developed process benefits from significant reduction in total solids and better biodegradability in the effluent, compared to non-oxidized vegetable tannins.

Effects of elk herbivory on vegetation and nitrogen processes

USGS Publications Warehouse

Schoenecker, Kathryn A.; Singer, Francis J.; Zeigenfuss, Linda C.; Binkley, Dan; Menezes, Romulo S.C.

2004-01-01

We used 35-year and 4-year ungulate exclosures to determine the effects of elk (Cervus elaphus) herbivory on above-ground and below-ground production and soil fertility on the elk winter range in Rocky Mountain National Park (RMNP), Colorado, USA. We used paired grazed and ungrazed plots to evaluate ungulate herbivory effects in short and tall willow (Salix spp.), aspen (Populus spp.), and upland grass/shrub vegetation associations. We measured nitrogen (N) fluxes (litter deposition, fecal and urinary deposition from elk, movements of N by elk, N mineralization, soil N availability, elk consumption rates) within the elk winter, above-ground and below-ground N pools (herbaceous, shrub and root biomass, %N in plants, roots, and soil), and N fluxes on and off the elk winter range (seasonal movement of N by elk). Nitrogen mineralization and soil nitrate (NO3) pools were reduced in the short willow community (P = 0.07 and 0.10, respectively; n = 4 sites) in grazed plots, but not in the upland grass/shrub community or tall willow sites (P >0.10). Annual growth of willows was reduced by 98% in grazed plots, relative to 35-year exclosures, and 66% relative to 4-year exclosures. Thus, height, canopy size, and litter biomass of willows were reduced, and N yield of willows was 64% less in grazed plots. We evaluated movement of N by elk among 6 major vegetation associations and found that elk grazed more and bedded less in willow vegetation association compared to mixed conifer, mesic meadow, and grassland/shrub associations (P = 0.014, 0.001, and 0.026, respectively), suggesting that elk herbivory and movement led to a net loss of N in the willow vegetation association. Elk spent less total time in willows than mesic meadow association, yet they consumed large amounts of willow plant biomass. We recommend management of elk numbers and elk herbivory that takes into consideration impacts to N process function, as negative effects from current levels of herbivory were observed

Effects of Freeze-Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages.

PubMed

Eisinaite, Viktorija; Vinauskiene, Rimante; Viskelis, Pranas; Leskauskaite, Daiva

2016-09-01

The aim of this study was to compare the chemical composition of freeze-dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze-dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p < 0.05) differed in their chemical composition: celery products contained higher amounts of nitrates, total phenolic compounds and lower amounts of sucrose, parsnip had higher concentration of proteins, leek was rich in fat. The analysis of pH, water activity, lactic acid bacteria, coagulase-positive staphylococci and coliforms content showed that the incorporation of freeze-dried vegetables had no negative effect on the fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p < 0.05) more stable during these processes. At the end of the ripening process the sausages made with lyophilised celery juice were characterised by higher lightness and lower hardness than those made with the addition of other vegetable products and control. Freeze-dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages. © 2016 Institute of Food Technologists®

Role of submerged vegetation in the retention processes of three plant protection products in flow-through stream mesocosms.

PubMed

Stang, Christoph; Wieczorek, Matthias Valentin; Noss, Christian; Lorke, Andreas; Scherr, Frank; Goerlitz, Gerhard; Schulz, Ralf

2014-07-01

Quantitative information on the processes leading to the retention of plant protection products (PPPs) in surface waters is not available, particularly for flow-through systems. The influence of aquatic vegetation on the hydraulic- and sorption-mediated mitigation processes of three PPPs (triflumuron, pencycuron, and penflufen; logKOW 3.3-4.9) in 45-m slow-flowing stream mesocosms was investigated. Peak reductions were 35-38% in an unvegetated stream mesocosm, 60-62% in a sparsely vegetated stream mesocosm (13% coverage with Elodea nuttallii), and in a similar range of 57-69% in a densely vegetated stream mesocosm (100% coverage). Between 89% and 93% of the measured total peak reductions in the sparsely vegetated stream can be explained by an increase of vegetation-induced dispersion (estimated with the one-dimensional solute transport model OTIS), while 7-11% of the peak reduction can be attributed to sorption processes. However, dispersion contributed only 59-71% of the peak reductions in the densely vegetated stream mesocosm, where 29% to 41% of the total peak reductions can be attributed to sorption processes. In the densely vegetated stream, 8-27% of the applied PPPs, depending on the logKOW values of the compounds, were temporarily retained by macrophytes. Increasing PPP recoveries in the aqueous phase were accompanied by a decrease of PPP concentrations in macrophytes indicating kinetic desorption over time. This is the first study to provide quantitative data on how the interaction of dispersion and sorption, driven by aquatic macrophytes, influences the mitigation of PPP concentrations in flowing vegetated stream systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prevalence and level of Listeria monocytogenes and other Listeria sp. in ready-to-eat minimally processed and refrigerated vegetables.

PubMed

Kovačević, Mira; Burazin, Jelena; Pavlović, Hrvoje; Kopjar, Mirela; Piližota, Vlasta

2013-04-01

Minimally processed and refrigerated vegetables can be contaminated with Listeria species bacteria including Listeria monocytogenes due to extensive handling during processing or by cross contamination from the processing environment. The objective of this study was to examine the microbiological quality of ready-to-eat minimally processed and refrigerated vegetables from supermarkets in Osijek, Croatia. 100 samples of ready-to-eat vegetables collected from different supermarkets in Osijek, Croatia, were analyzed for presence of Listeria species and Listeria monocytogenes. The collected samples were cut iceberg lettuces (24 samples), other leafy vegetables (11 samples), delicatessen salads (23 samples), cabbage salads (19 samples), salads from mixed (17 samples) and root vegetables (6 samples). Listeria species was found in 20 samples (20 %) and Listeria monocytogenes was detected in only 1 sample (1 %) of cut red cabbage (less than 100 CFU/g). According to Croatian and EU microbiological criteria these results are satisfactory. However, the presence of Listeria species and Listeria monocytogenes indicates poor hygiene quality. The study showed that these products are often improperly labeled, since 24 % of analyzed samples lacked information about shelf life, and 60 % of samples lacked information about storage conditions. With regard to these facts, cold chain abruption with extended use after expiration date is a probable scenario. Therefore, the microbiological risk for consumers of ready-to-eat minimally processed and refrigerated vegetables is not completely eliminated.

7 CFR 318.13-14 - Movement of processed fruits, vegetables, and other products.

Code of Federal Regulations, 2010 CFR

2010-01-01

.../import_export/plants/manuals/ports/downloads/hawaii.pdf and http://www.aphis.usda.gov/import_export/plants/manuals/ports/downloads/puerto_rico.pdf. (b) Consignments of processed fruits, vegetables, or...

Floristic and vegetation successional processes within landslides in a Mediterranean environment.

PubMed

Neto, Carlos; Cardigos, Patrícia; Oliveira, Sérgio Cruz; Zêzere, José Luís

2017-01-01

Floristic and vegetation analysis in seven Mediterranean landslides led to the understanding of the successional processes occurring in different landslide disturbed sectors. Our study showed that in landslides that occurred between 1996 and 2010 there is a clear differentiation between the three main landslide sectors (scarp, main body and foot) concerning floristic composition, vegetation structure, floristic richness, successional processes and plant functional type. Additional differences were found between landslide areas and undisturbed agricultural areas adjacent to landslides. In this study 48 floristic relevés were made using a stratified random sampling design. The main landslide body exhibits the highest floristic richness whereas the landslide scarp has the lowest coverage rate and the highest presence of characteristic species from ruderal and strongly perturbed habitats. Finally, the landslide foot shows a late stage in the succession (maquis or pre-forest stage) with a high dominance of vines. We further discuss the importance of landslides as reservoirs of biodiversity especially for Mediterranean orchids. Copyright © 2016 Elsevier B.V. All rights reserved.

Preliminary process engineering evaluation of ethanol production from vegetative crops

NASA Astrophysics Data System (ADS)

Moreira, A. R.; Linden, J. C.; Smith, D. H.; Villet, R. H.

1982-12-01

Vegetative crops show good potential as feedstock for ethanol production via cellulose hydrolysis and yeast fermentation. The low levels of lignin encountered in young plant tissues show an inverse relationship with the high cellulose digestibility during hydrolysis with cellulose enzymes. Ensiled sorghum species and brown midrib mutants of sorghum exhibit high glucose yields after enzyme hydrolysis as well. Vegetative crop materials as candidate feedstocks for ethanol manufacture should continue to be studied. The species studied so far are high value cash crops and result in relatively high costs for the final ethanol product. Unconventional crops, such as pigweed, kochia, and Russian thistle, which can use water efficiently and grow on relatively arid land under conditions not ideal for food production, should be carefully evaluated with regard to their cultivation requirements, photosynthesis rates, and cellulose digestibility. Such crops should result in more favorable process economics for alcohol production.

Prevalence of Listeria monocytogenes in Retail Lightly Pickled Vegetables and Its Successful Control at Processing Plants.

PubMed

Taguchi, Masumi; Kanki, Masashi; Yamaguchi, Yuko; Inamura, Hideichi; Koganei, Yosuke; Sano, Tetsuya; Nakamura, Hiromi; Asakura, Hiroshi

2017-03-01

Incidences of food poisoning traced to nonanimal food products have been increasingly reported. One of these was a recent large outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 infection from the consumption of lightly pickled vegetables, indicating the necessity of imposing hygienic controls during manufacturing. However, little is known about the bacterial contamination levels in these minimally processed vegetables. Here we examined the prevalence of STEC, Salmonella spp., and Listeria monocytogenes in 100 lightly pickled vegetable products manufactured at 55 processing factories. Simultaneously, we also performed quantitative measurements of representative indicator bacteria (total viable counts, coliform counts, and β-glucuronidase-producing E. coli counts). STEC and Salmonella spp. were not detected in any of the samples; L. monocytogenes was detected in 12 samples manufactured at five of the factories. Microbiological surveillance at two factories (two surveys at factory A and three surveys at factory B) between June 2014 and January 2015 determined that the areas predominantly contaminated with L. monocytogenes included the refrigerators and packaging rooms. Genotyping provided further evidence that the contaminants found in these areas were linked to those found in the final products. Taken together, we demonstrated the prevalence of L. monocytogenes in lightly pickled vegetables sold at the retail level. Microbiological surveillance at the manufacturing factories further clarified the sources of the contamination in the retail products. These data indicate the necessity of implementing adequate monitoring programs to minimize health risks attributable to the consumption of these minimally processed vegetables.

A novel approach for calculating shelf life of minimally processed vegetables.

PubMed

Corbo, Maria Rosaria; Del Nobile, Matteo Alessandro; Sinigaglia, Milena

2006-01-15

Shelf life of minimally processed vegetables is often calculated by using the kinetic parameters of Gompertz equation as modified by Zwietering et al. [Zwietering, M.H., Jongenburger, F.M., Roumbouts, M., van't Riet, K., 1990. Modelling of the bacterial growth curve. Applied and Environmental Microbiology 56, 1875-1881.] taking 5x10(7) CFU/g as the maximum acceptable contamination value consistent with acceptable quality of these products. As this method does not allow estimation of the standard errors of the shelf life, in this paper the modified Gompertz equation was re-parameterized to directly include the shelf life as a fitting parameter among the Gompertz parameters. Being the shelf life a fitting parameter is possible to determine its confidence interval by fitting the proposed equation to the experimental data. The goodness-of-fit of this new equation was tested by using mesophilic bacteria cell loads from different minimally processed vegetables (packaged fresh-cut lettuce, fennel and shredded carrots) that differed for some process operations or for package atmosphere. The new equation was able to describe the data well and to estimate the shelf life. The results obtained emphasize the importance of using the standard errors for the shelf life value to show significant differences among the samples.

7 CFR 318.13-14 - Movement of processed fruits, vegetables, and other products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... vegetables manuals for those States. These manuals are available on the Internet at http://www.aphis.usda.gov... other products that have not been processed sufficiently as to be incapable of harboring fruit flies are...

Effect of storage, processing and cooking on glucosinolate content of Brassica vegetables.

PubMed

Song, Lijiang; Thornalley, Paul J

2007-02-01

Epidemiological studies have shown that consumption of Brassica vegetables decrease the risk of cancer. These associations are linked to dietary intake of glucosinolates and their metabolism to cancer preventive isothiocyanates. Bioavailability of glucosinolates and related isothiocyanates are influenced by storage and culinary processing of Brassica vegetables. In this work, the content of the 7 major glucosinolates in broccoli, Brussels sprouts, cauliflower and green cabbage and their stability under different storage and cooking conditions is examined. Glucosinolates and isothiocyanates were quantified by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). Isothiocyanates were detected with high sensitivity as the corresponding thiourea derivatives. Storage at ambient temperature and in a domestic refrigerator showed no significant difference and a minor loss (9-26%) of glucosinolate levels over 7 days. Vegetables shredded finely showed a marked decline of glucosinolate level with post-shredding dwell time - up to 75% over 6h. Glucosinolate losses were detected partly as isothiocyanates. Cooking by steaming, microwaving and stir-fry did not produce significant loss of glucosinolates whereas boiling showed significant losses by leaching into cooking water. Most of the loss of the glucosinolates (approximately 90%) was detected in the cooking water. Increased bioavailability of dietary isothiocyanates may be achieved by avoiding boiling of vegetables.

Effect of fruit and vegetable processing on reduction of synthetic pyrethroid residues.

PubMed

Chauhan, Reena; Kumari, Beena; Rana, M K

2014-01-01

In this review, we emphasize that the advantages associated with applying pesticides to enhance agricultural productivity must be weighed against the possible health hazards arising from the appearance of toxic pesticide residues in food. First and foremost, pesticides should be handled and applied in compliance with good agricultural practices to minimize environmental or food commodity contamination.In developing countries, good agricultural practices are not fully abided by.When vegetables are produced in such countries, pesticides are applied or prospectively applied at each growth stage of the crop. Hence, contamination of vegetables and other food commodities occur. It is well known that processing of food derived from pesticide treated crop commodities can serve to reduce residues that reach consumers. Food safety can therefore partially be enhanced by employing suitable food processing techniques and appropriate storage periods, even in developing countries. Even common and simple household processing techniques for certain foods acquire significance as means to reduce the intake of harmful pesticide food residues.Pesticide residue levels in post-harvest raw agricultural commodities (RAC) are affected by the storage, handling and the processing steps they pass through, while being prepared for human consumption. The review of cogent literature presented in this article demonstrated differences among the pyrethroid insecticide residues present on or in foods, depending on how the RAC from which they came were processed for consumption. Peeling vegetables or fruit reduced pyrethroid residues the most (60-100% ), and juicing was nearly as effective in reducing residues (70-100% ). The least reduction occurred for foodstuffs that were only washed with tap water (I 0-70% ). Washing RACs with saline water and detergent was more effective(34-60%) in reducing residues than was simple washing under tap water. Freezing is also effective in reducing residue levels and

Preserved feedforward but impaired top-down processes in the vegetative state.

PubMed

Boly, Melanie; Garrido, Marta Isabel; Gosseries, Olivia; Bruno, Marie-Aurélie; Boveroux, Pierre; Schnakers, Caroline; Massimini, Marcello; Litvak, Vladimir; Laureys, Steven; Friston, Karl

2011-05-13

Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an impairment of top-down processes, involved in recurrent neuronal message-passing and the generation of long-latency electrophysiological responses, might provide a more reliable correlate of consciousness in severely brain-damaged patients, than frontoparietal responses. We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception.

Assessment of Vegetation Destruction Due to Wenchuan Earthquake and Its Recovery Process Using MODIS Data

NASA Astrophysics Data System (ADS)

Zou, Z.; Xiao, X.

2015-12-01

With a high temporal resolution and a large covering area, MODIS data are particularly useful in assessing vegetation destruction and recovery of a wide range of areas. In this study, MOD13Q1 data of the growing season (Mar. to Nov.) are used to calculate the Maximum NDVI (NDVImax) of each year. This study calculates each pixel's mean and standard deviation of the NDVImaxs in the 8 years before the earthquake. If the pixel's NDVImax of 2008 is two standard deviation smaller than the mean NDVImax, this pixel is detected as a vegetation destructed pixel. For each vegetation destructed pixel, its similar pixels of the same vegetation type are selected within the latitude difference of 0.5 degrees, altitude difference of 100 meters and slope difference of 3 degrees. Then the NDVImax difference of each vegetation destructed pixel and its similar pixels are calculated. The 5 similar pixels with the smallest NDVImax difference in the 8 years before the earthquake are selected as reference pixels. The mean NDVImaxs of these reference pixels after the earthquake are calculated and serve as the criterion to assess the vegetation recovery process.

Synthesis and study of the roadside vegetation establishment process.

DOT National Transportation Integrated Search

2011-05-01

The Texas Pollutant Discharge Elimination System (TPDES), which is administered and enforced by the : Texas Commission on Environmental Quality (TCEQ), requires perennial vegetation to 70 percent of native : or adjacent background vegetation before a...

Inactivation of Salmonella Enteritidis on lettuces used by minimally processed vegetable industries.

PubMed

Silveira, Josete Bailardi; Hessel, Claudia Titze; Tondo, Eduardo Cesar

2017-01-30

Washing and disinfection methods used by minimally processed vegetable industries of Southern Brazil were reproduced in laboratory in order to verify their effectiveness to reduce Salmonella Enteritidis SE86 (SE86) on lettuce. Among the five industries investigated, four carried out washing with potable water followed by disinfection with 200 ppm sodium hypochlorite during different immersion times. The washing procedure alone decreased approximately 1 log CFU/g of SE86 population and immersion times of 1, 2, 5, and 15 minutes in disinfectant solution demonstrated reduction rates ranging from 2.06±0.10 log CFU/g to 3.01±0.21 log CFU/g. Rinsing alone was able to reduce counts from 0.12±0.63 log CFU/g to 1.90±1.07 log CFU/g. The most effective method was washing followed by disinfection with 200 ppm sodium hypochlorite for 15 minutes and final rinse with potable water, reaching 5.83 log CFU/g of reduction. However, no statistical differences were observed on the reduction rates after different immersion times. A time interval of 1 to 2 minutes may be an advantage to the minimally vegetable processed industries in order to optimize the process without putting at risk food safety.

Energy Efficiency Improvement and Cost Saving Opportunities for the Fruit and Vegetable Processing Industry. An ENERGY STAR Guide for Energy and Plant Managers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masanet, Eric; Masanet, Eric; Worrell, Ernst

2008-01-01

The U.S. fruit and vegetable processing industry--defined in this Energy Guide as facilities engaged in the canning, freezing, and drying or dehydrating of fruits and vegetables--consumes over $800 million worth of purchased fuels and electricity per year. Energy efficiency improvement isan important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. fruit and vegetable processing industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implementedmore » at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. fruit and vegetable processing industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures applicable to fruit and vegetable processing plants are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in fruit and vegetable processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. Given the importance of water in fruit and vegetable processing, a summary of basic, proven measures for improving plant-level water efficiency are also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. fruit and vegetable processing industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures--as well as on their applicability to different

75 FR 6364 - Process for Requesting a Variance From Vegetation Standards for Levees and Floodwalls

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-09

..., channels, or shore- line or river-bank protection systems such as revetments, sand dunes, and barrier...) toe (subject to preexisting right-of-way). f. The vegetation variance process is not a mechanism to...

21 CFR 133.174 - Pasteurized process cheese food with fruits, vegetables, or meats.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., vegetables, or meats. 133.174 Section 133.174 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Requirements for Specific Standardized Cheese and Related Products § 133.174 Pasteurized process cheese food... cheese food by § 133.173, except that: (1) Its milk fat content is not less than 22 percent. (2) It...

Vegetation Monitoring with Gaussian Processes and Latent Force Models

NASA Astrophysics Data System (ADS)

Camps-Valls, Gustau; Svendsen, Daniel; Martino, Luca; Campos, Manuel; Luengo, David

2017-04-01

Monitoring vegetation by biophysical parameter retrieval from Earth observation data is a challenging problem, where machine learning is currently a key player. Neural networks, kernel methods, and Gaussian Process (GP) regression have excelled in parameter retrieval tasks at both local and global scales. GP regression is based on solid Bayesian statistics, yield efficient and accurate parameter estimates, and provides interesting advantages over competing machine learning approaches such as confidence intervals. However, GP models are hampered by lack of interpretability, that prevented the widespread adoption by a larger community. In this presentation we will summarize some of our latest developments to address this issue. We will review the main characteristics of GPs and their advantages in vegetation monitoring standard applications. Then, three advanced GP models will be introduced. First, we will derive sensitivity maps for the GP predictive function that allows us to obtain feature ranking from the model and to assess the influence of examples in the solution. Second, we will introduce a Joint GP (JGP) model that combines in situ measurements and simulated radiative transfer data in a single GP model. The JGP regression provides more sensible confidence intervals for the predictions, respects the physics of the underlying processes, and allows for transferability across time and space. Finally, a latent force model (LFM) for GP modeling that encodes ordinary differential equations to blend data-driven modeling and physical models of the system is presented. The LFM performs multi-output regression, adapts to the signal characteristics, is able to cope with missing data in the time series, and provides explicit latent functions that allow system analysis and evaluation. Empirical evidence of the performance of these models will be presented through illustrative examples.

Analysis of vegetation dynamics using time-series vegetation index data from Earth observation satellites

NASA Astrophysics Data System (ADS)

Rodrigues, Arlete da Silva

As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de

21 CFR 133.180 - Pasteurized process cheese spread with fruits, vegetables, or meats.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., vegetables, or meats. 133.180 Section 133.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Requirements for Specific Standardized Cheese and Related Products § 133.180 Pasteurized process cheese spread... spread by § 133.179, except that: (1) It contains one or any mixture of two or more of the following: Any...

Effect of combination processing on the microbial, chemical and sensory quality of ready-to-eat (RTE) vegetable pulav

NASA Astrophysics Data System (ADS)

Kumar, R.; George, Johnsy; Rajamanickam, R.; Nataraju, S.; Sabhapathy, S. N.; Bawa, A. S.

2011-12-01

Effect of irradiation in combination with retort processing on the shelf life and safety aspects of an ethnic Indian food product like vegetable pulav was investigated. Gamma irradiation of RTE vegetable pulav was carried out at different dosage rates with 60Co followed by retort processing. The combination processed samples were analysed for microbiological, chemical and sensory characteristics. Microbiological analysis indicated that irradiation in combination with retort processing has significantly reduced the microbial loads whereas the chemical and sensory analysis proved that this combination processing is effective in retaining the properties even after storage for one year at ambient conditions. The results also indicated that a minimum irradiation dosage at 4.0 kGy along with retort processing at an F0 value of 2.0 is needed to achieve the desired shelf life with improved organoleptic qualities.

The effect of High Pressure and High Temperature processing on carotenoids and chlorophylls content in some vegetables.

PubMed

Sánchez, Celia; Baranda, Ana Beatriz; Martínez de Marañón, Iñigo

2014-11-15

The effect of High Pressure (HP) and High Pressure High Temperature (HPHT) processing on carotenoid and chlorophyll content of six vegetables was evaluated. In general, carotenoid content was not significantly influenced by HP or HPHT treatments (625 MPa; 5 min; 20, 70 and 117 °C). Regarding chlorophylls, HP treatment caused no degradation or slight increases, while HPHT processes degraded both chlorophylls. Chlorophyll b was more stable than chlorophyll a at 70 °C, but both of them were highly degraded at 117 °C. HPHT treatment at 117 °C provided products with a good retention of carotenoids and colour in the case of red vegetables. Even though the carotenoids also remained in the green vegetables, their chlorophylls and therefore their colour were so affected that milder temperatures need to be applied. As an industrial scale equipment was used, results will be useful for future industrial implementation of this technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial Evaluation of Fresh, Minimally-processed Vegetables and Bagged Sprouts from Chain Supermarkets

PubMed Central

Jeddi, Maryam Zare; Yunesian, Masud; Gorji, Mohamad Es'haghi; Noori, Negin; Pourmand, Mohammad Reza

2014-01-01

ABSTRACT The aim of this study was to evaluate the bacterial and fungal quality of minimally-processed vegetables (MPV) and sprouts. A total of 116 samples of fresh-cut vegetables, ready-to-eat salads, and mung bean and wheat sprouts were randomly collected and analyzed. The load of aerobic mesophilic bacteria was minimum and maximum in the fresh-cut vegetables and fresh mung bean sprouts respectively, corresponding to populations of 5.3 and 8.5 log CFU/g. E. coli O157:H7 was found to be absent in all samples; however,  other E. coli strains were detected in 21 samples (18.1%), and Salmonella spp. were found in one mung bean (3.1%) and one ready-to-eat salad sample (5%). Yeasts were the predominant organisms and were found in 100% of the samples. Geotrichum, Fusarium, and Penicillium spp. were the most prevalent molds in mung sprouts while Cladosporium and Penicillium spp. were most frequently found in ready-to-eat salad samples. According to results from the present study, effective control measures should be implemented to minimize the microbiological contamination of fresh produce sold in Tehran, Iran. PMID:25395902

Microbial evaluation of fresh, minimally-processed vegetables and bagged sprouts from chain supermarkets.

PubMed

Jeddi, Maryam Zare; Yunesian, Masud; Gorji, Mohamad Es'haghi; Noori, Negin; Pourmand, Mohammad Reza; Khaniki, Gholam Reza Jahed

2014-09-01

The aim of this study was to evaluate the bacterial and fungal quality of minimally-processed vegetables (MPV) and sprouts. A total of 116 samples of fresh-cut vegetables, ready-to-eat salads, and mung bean and wheat sprouts were randomly collected and analyzed. The load of aerobic mesophilic bacteria was minimum and maximum in the fresh-cut vegetables and fresh mung bean sprouts respectively, corresponding to populations of 5.3 and 8.5 log CFU/g. E. coli O157:H7 was found to be absent in all samples; however,  other E. coli strains were detected in 21 samples (18.1%), and Salmonella spp. were found in one mung bean (3.1%) and one ready-to-eat salad sample (5%). Yeasts were the predominant organisms and were found in 100% of the samples. Geotrichum, Fusarium, and Penicillium spp. were the most prevalent molds in mung sprouts while Cladosporium and Penicillium spp. were most frequently found in ready-to-eat salad samples. According to results from the present study, effective control measures should be implemented to minimize the microbiological contamination of fresh produce sold in Tehran, Iran.

Sensitivity of volatile organic compounds (VOCs) and ozone to land surface processes and vegetation distributions in California

NASA Astrophysics Data System (ADS)

Zhao, C.; Huang, M.; Fast, J. D.; Berg, L. K.; Qian, Y.; Guenther, A. B.; Gu, D.; Shrivastava, M. B.; Liu, Y.; Walters, S.; Jin, J.

2014-12-01

Current climate models still have large uncertainties in estimating biogenic trace gases, which can significantly affect secondary organic aerosol (SOA) formation and ultimately aerosol radiative forcing. These uncertainties result from many factors, including coupling strategy between biogenic emissions and land-surface schemes and specification of vegetation types, both of which can affect the simulated near-surface fluxes of biogenic volatile organic compounds (VOCs). In this study, sensitivity experiments are conducted using the Weather Research and Forecasting model with chemistry (WRF-Chem) to examine the sensitivity of simulated VOCs and ozone to land surface processes and vegetation distributions in California. The measurements collected during the California Nexus of Air Quality and Climate Experiment (CalNex) and the Carbonaceous Aerosol and Radiative Effects Study (CARES) conducted during May and June of 2010 provide a good opportunity to evaluate the simulations. First, the biogenic VOC emissions in the WRF-Chem simulations with the two land surface schemes, Noah and CLM4, are estimated by the Model of Emissions of Gases and Aerosols from Nature version one (MEGANv1), which has been publicly released and widely used with WRF-Chem. The impacts of land surface processes on estimating biogenic VOC emissions and simulating VOCs and ozone are investigated. Second, in this study, a newer version of MEGAN (MEGANv2.1) is coupled with CLM4 as part of WRF-Chem to examine the sensitivity of biogenic VOC emissions to the MEGAN schemes used and determine the importance of using a consistent vegetation map between a land surface scheme and the biogenic VOC emission scheme. Specifically, MEGANv2.1 is embedded into the CLM4 scheme and shares a consistent vegetation map for estimating biogenic VOC emissions. This is unlike MEGANv1 in WRF-Chem that uses a standalone vegetation map that differs from what is used in land surface schemes. Furthermore, we examine the impact

Waveform LiDAR processing: comparison of classic approaches and optimized Gold deconvolution to characterize vegetation structure and terrain elevation

NASA Astrophysics Data System (ADS)

Zhou, T.; Popescu, S. C.; Krause, K.

2016-12-01

Waveform Light Detection and Ranging (LiDAR) data have advantages over discrete-return LiDAR data in accurately characterizing vegetation structure. However, we lack a comprehensive understanding of waveform data processing approaches under different topography and vegetation conditions. The objective of this paper is to highlight a novel deconvolution algorithm, the Gold algorithm, for processing waveform LiDAR data with optimal deconvolution parameters. Further, we present a comparative study of waveform processing methods to provide insight into selecting an approach for a given combination of vegetation and terrain characteristics. We employed two waveform processing methods: 1) direct decomposition, 2) deconvolution and decomposition. In method two, we utilized two deconvolution algorithms - the Richardson Lucy (RL) algorithm and the Gold algorithm. The comprehensive and quantitative comparisons were conducted in terms of the number of detected echoes, position accuracy, the bias of the end products (such as digital terrain model (DTM) and canopy height model (CHM)) from discrete LiDAR data, along with parameter uncertainty for these end products obtained from different methods. This study was conducted at three study sites that include diverse ecological regions, vegetation and elevation gradients. Results demonstrate that two deconvolution algorithms are sensitive to the pre-processing steps of input data. The deconvolution and decomposition method is more capable of detecting hidden echoes with a lower false echo detection rate, especially for the Gold algorithm. Compared to the reference data, all approaches generate satisfactory accuracy assessment results with small mean spatial difference (<1.22 m for DTMs, < 0.77 m for CHMs) and root mean square error (RMSE) (<1.26 m for DTMs, < 1.93 m for CHMs). More specifically, the Gold algorithm is superior to others with smaller root mean square error (RMSE) (< 1.01m), while the direct decomposition approach

Vegetation extraction from high-resolution satellite imagery using the Normalized Difference Vegetation Index (NDVI)

NASA Astrophysics Data System (ADS)

AlShamsi, Meera R.

2016-10-01

Over the past years, there has been various urban development all over the UAE. Dubai is one of the cities that experienced rapid growth in both development and population. That growth can have a negative effect on the surrounding environment. Hence, there has been a necessity to protect the environment from these fast pace changes. One of the major impacts this growth can have is on vegetation. As technology is evolving day by day, there is a possibility to monitor changes that are happening on different areas in the world using satellite imagery. The data from these imageries can be utilized to identify vegetation in different areas of an image through a process called vegetation detection. Being able to detect and monitor vegetation is very beneficial for municipal planning and management, and environment authorities. Through this, analysts can monitor vegetation growth in various areas and analyze these changes. By utilizing satellite imagery with the necessary data, different types of vegetation can be studied and analyzed, such as parks, farms, and artificial grass in sports fields. In this paper, vegetation features are detected and extracted through SAFIY system (i.e. the Smart Application for Feature extraction and 3D modeling using high resolution satellite ImagerY) by using high-resolution satellite imagery from DubaiSat-2 and DEIMOS-2 satellites, which provide panchromatic images of 1m resolution and spectral bands (red, green, blue and near infrared) of 4m resolution. SAFIY system is a joint collaboration between MBRSC and DEIMOS Space UK. It uses image-processing algorithms to extract different features (roads, water, vegetation, and buildings) to generate vector maps data. The process to extract green areas (vegetation) utilize spectral information (such as, the red and near infrared bands) from the satellite images. These detected vegetation features will be extracted as vector data in SAFIY system and can be updated and edited by end-users, such as

Coatings for minimally processed fruits and vegetables

USDA-ARS?s Scientific Manuscript database

Fresh-cut fruit and vegetables are gaining increasing popularity and market share. Techniques to enhance stability of fresh cut produce are reviewed. Among these techniques, edibles coatings can provide protection against dehydration, microbial decay and decrease events related to physiological sene...

Carbon Inputs From Riparian Vegetation Limit Oxidation of Physically Bound Organic Carbon Via Biochemical and Thermodynamic Processes: OC Oxidation Processes Across Vegetation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graham, Emily B.; Tfaily, Malak M.; Crump, Alex R.

In light of increasing terrestrial carbon (C) transport across aquatic boundaries, the mechanisms governing organic carbon (OC) oxidation along terrestrial-aquatic interfaces are crucial to future climate predictions. Here, we investigate biochemistry, metabolic pathways, and thermodynamics corresponding to OC oxidation in the Columbia River corridor. We leverage natural vegetative differences to encompass variation in terrestrial C inputs. Our results suggest that decreases in terrestrial C deposition associated with diminished riparian vegetation induce oxidation of physically-bound (i.e., mineral and microbial) OC at terrestrial-aquatic interfaces. We also find that contrasting metabolic pathways oxidize OC in the presence and absence of vegetation and—in directmore » conflict with the concept of ‘priming’—that inputs of water-soluble and thermodynamically-favorable terrestrial OC protects bound-OC from oxidation. Based on our results, we propose a mechanistic conceptualization of OC oxidation along terrestrial-aquatic interfaces that can be used to model heterogeneous patterns of OC loss under changing land cover distributions.« less

Demonstration of wetland vegetation mapping in Florida from computer-processed satellite and aircraft multispectral scanner data

NASA Technical Reports Server (NTRS)

Butera, M. K.

1979-01-01

The success of remotely mapping wetland vegetation of the southwestern coast of Florida is examined. A computerized technique to process aircraft and LANDSAT multispectral scanner data into vegetation classification maps was used. The cost effectiveness of this mapping technique was evaluated in terms of user requirements, accuracy, and cost. Results indicate that mangrove communities are classified most cost effectively by the LANDSAT technique, with an accuracy of approximately 87 percent and with a cost of approximately 3 cent per hectare compared to $46.50 per hectare for conventional ground survey methods.

Influence of high-pressure processing on the profile of polyglutamyl 5-methyltetrahydrofolate in selected vegetables.

PubMed

Wang, Chao; Riedl, Ken M; Somerville, Jeremy; Balasubramaniam, V M; Schwartz, Steven J

2011-08-24

In plants, folate occurs predominantly as 5-methyltetrahydrofolate (5MTHF) polyglutamyl forms. Differences in stability and bioavailability of food folate compared to synthetic folic acid have been attributed to the presence of the polyglutamyl chain. High-pressure processing (HPP) was tested for whether it might shorten polyglutamyl chains of 5MTHF species in fresh vegetables by enabling action of native γ-glutamylhydrolase (GGH). A validated ultrahigh-performance reversed-phase liquid chromatography-tandem mass spectrometry method using stable isotope as internal standard was applied for characterizing 5MTHF polyglutamyl profiles. HPP conditions included 300, 450, and 600 MPa at 30 °C for 0 or 5 min, and vegetables were vacuum-packed before treatment. Investigated vegetables included cauliflower (Brassica oleracea), baby carrots (Daucus carota), and carrot greens (D. carota). HPP treatment caused conversion of polyglutamyl 5MTHF species to short-chain and monoglutamyl forms. Maximal conversion of polyglutamyl folate to monoglutamyl folate occurred at the highest pressure/time combination investigated, 600 MPa/30 °C/5 min. Under this condition, cauliflower monoglutamyl folate increased nearly 4-fold, diglutamyl folate 32-fold, and triglutamyl folate 8-fold; carrot monoglutamyl increased 23-fold and diglutamyl 32-fold; and carrot greens monoglutamyl increased 2.5-fold and the diglutamyl form 19-fold. Although some folate degradation was observed at certain intermediate HPP conditions, total 5MTHF folate was largely preserved at 600 MPa/5 min. Thus, HPP of raw vegetables is a feasible strategy for enhancing vegetable monoglutamate 5MTHF.

Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands

NASA Astrophysics Data System (ADS)

Trivisonno, Franco; Rodriguez, Jose F.; Riccardi, Gerardo; Saco, Patricia; Stenta, Hernan

2014-05-01

Estuarine wetlands of south eastern Australia, typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasess terrestrial forest. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which buffer areas for landward migration are not available, saltmarsh can be lost due to mangrove encroachment. As a result of mangrove invasion associated in part with raising estuary water levels and urbanisation, coastal saltmarsh in parts of south-eastern Australia has been declared an endangered ecological community. Predicting estuarine wetlands response to sea-level rise requires modelling the coevolving dynamics of water flow, soil and vegetation. This paper presents preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model simulates continuous tidal inflow into the wetland, and accounts for the effect of varying vegetation types on flow resistance. Coevolution effects appear as vegetation types are updated based on their preference to prevailing hydrodynamic conditions. The model also considers that accretion values vary with vegetation type. Simulations are driven using local information collected over several years, which includes estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further saltmarsh loss under current conditions of moderate increase of estuary water levels.

Stimulants of Toll-like receptor (TLR)-2 and TLR-4 are abundant in certain minimally-processed vegetables.

PubMed

Erridge, Clett

2011-06-01

Stimulants of the innate immune receptors Toll-like receptor (TLR)-2 and TLR4 have been shown to promote insulin resistance and atherosclerosis in animal models of these diseases. As minimally processed vegetables (MPV) can contain a relatively large bacterial load compared to other foodstuffs, we aimed to quantify the abundance of stimulants of TLR2 and TLR4 in MPV using a transfection-based bioassay calibrated with Escherichia coli LPS and the synthetic lipopeptide Pam(3)CSK(4). Of 5 classes of MPV and 3 classes of related vegetable products considered to be likely to contain a high microbial load, diced onion and bean sprouts contained the highest levels of stimulants of TLR2 (up to 18.5 μg Pam(3)CSK(4)-equivalents per g) and TLR4 (up to 11.4 μg LPS-equivalents per g). By contrast, the majority of fresh whole vegetables examined reproducibly contained minimal or undetectable levels of TLR2- or TLR4-stimulants. The accumulation of TLR-stimulants in MPVs correlated well with growth of enterobacterial spoilage organisms. In conclusion, the modern trend towards eating minimally processed vegetables rather than whole foods is likely to be associated with increased oral exposure to stimulants of TLR2 and TLR4. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Potentialities of the vegetative resonance test for diagnostics of hyperplastic processes in vocal folds].

PubMed

Ukhankova, N I; Sotskaia, T Iu

2010-01-01

The objective of the present study was to evaluate potentialities of the vegetative resonance test (VRT) for the elucidation of metabolic aspects of the inflammatory process in different forms of chronic vocal fold hyperplasty. The proposed diagnostic criteria characterize the inflammatory process in the larynx, specific features of metabolism in patients presenting with catarrhal and oedematopolypous laryngitis, characteristic changes in oedematofibrous and fibrous polyps. The use of VRT allowed diagnostic criteria for precarcinogenic conditions in the larynx to be developed.

Visual processing during recovery from vegetative state to consciousness: comparing behavioral indices to brain responses.

PubMed

Wijnen, V J M; Eilander, H J; de Gelder, B; van Boxtel, G J M

2014-11-01

Auditory stimulation is often used to evoke responses in unresponsive patients who have suffered severe brain injury. In order to investigate visual responses, we examined visual evoked potentials (VEPs) and behavioral responses to visual stimuli in vegetative patients during recovery to consciousness. Behavioral responses to visual stimuli (visual localization, comprehension of written commands, and object manipulation) and flash VEPs were repeatedly examined in eleven vegetative patients every two weeks for an average period of 2.6months, and patients' VEPs were compared to a healthy control group. Long-term outcome of the patients was assessed 2-3years later. Visual response scores increased during recovery to consciousness for all scales: visual localization, comprehension of written commands, and object manipulation. VEP amplitudes were smaller, and latencies were longer in the patient group relative to the controls. VEPs characteristics at first measurement were related to long-term outcome up to three years after injury. Our findings show the improvement of visual responding with recovery from the vegetative state to consciousness. Elementary visual processing is present, yet according to VEP responses, poorer in vegetative and minimally conscious state than in healthy controls, and remains poorer when patients recovered to consciousness. However, initial VEPs are related to long-term outcome. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Vegetation as a tool in the interpretation of fluvial geomorphic processes and landforms

USGS Publications Warehouse

Hupp, Cliff R.; Dufour, S; Bornette, G

2016-01-01

This chapter exemplifies that vegetation can be used as a tool for geomorphic interpretation in several major ways. It presents a general overview: through dendrogeomorphic analysis (tree rings) to estimate the timing of important geomorphic events including floods and mass wasting and to estimate rates of erosion and sedimentation; through the documentation and interpretation of species distributional patterns that are established in response to prevailing hydrogeomorphic conditions; and through the role that it plays, depending on size, shape and growth form, in flow rates and subsequent erosion and deposition processes. Floods, from prolonged inundation characteristic of relatively large, low-gradient basins to high-gradient and short-period destructive events, are the most important extrinsic factor in bottomland systems. Vegetation organization, composition and plant community dynamics on river floodplains are controlled by disturbance type and scale, and biological characteristics of plants linked to resistance to disturbance, resilience and competitive ability.

Effects of food processing on pesticide residues in fruits and vegetables: a meta-analysis approach.

PubMed

Keikotlhaile, B M; Spanoghe, P; Steurbaut, W

2010-01-01

Pesticides are widely used in food production to increase food security despite the fact that they can have negative health effects on consumers. Pesticide residues have been found in various fruits and vegetables; both raw and processed. One of the most common routes of pesticide exposure in consumers is via food consumption. Most foods are consumed after passing through various culinary and processing treatments. A few literature reviews have indicated the general trend of reduction or concentration of pesticide residues by certain methods of food processing for a particular active ingredient. However, no review has focused on combining the obtained results from different studies on different active ingredients with differences in experimental designs, analysts and analysis equipment. In this paper, we present a meta-analysis of response ratios as a possible method of combining and quantifying effects of food processing on pesticide residue levels. Reduction of residue levels was indicated by blanching, boiling, canning, frying, juicing, peeling and washing of fruits and vegetables with an average response ratio ranging from 0.10 to 0.82. Baking, boiling, canning and juicing indicated both reduction and increases for the 95% and 99.5% confidence intervals. Copyright 2009 Elsevier Ltd. All rights reserved.

Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape

PubMed Central

Glenn, Edward P.; Huete, Alfredo R.; Nagler, Pamela L.; Nelson, Stephen G.

2008-01-01

Vegetation indices (VIs) are among the oldest tools in remote sensing studies. Although many variations exist, most of them ratio the reflection of light in the red and NIR sections of the spectrum to separate the landscape into water, soil, and vegetation. Theoretical analyses and field studies have shown that VIs are near-linearly related to photosynthetically active radiation absorbed by a plant canopy, and therefore to light-dependent physiological processes, such as photosynthesis, occurring in the upper canopy. Practical studies have used time-series VIs to measure primary production and evapotranspiration, but these are limited in accuracy to that of the data used in ground truthing or calibrating the models used. VIs are also used to estimate a wide variety of other canopy attributes that are used in Soil-Vegetation-Atmosphere Transfer (SVAT), Surface Energy Balance (SEB), and Global Climate Models (GCM). These attributes include fractional vegetation cover, leaf area index, roughness lengths for turbulent transfer, emissivity and albedo. However, VIs often exhibit only moderate, non-linear relationships to these canopy attributes, compromising the accuracy of the models. We use case studies to illustrate the use and misuse of VIs, and argue for using VIs most simply as a measurement of canopy light absorption rather than as a surrogate for detailed features of canopy architecture. Used this way, VIs are compatible with “Big Leaf” SVAT and GCMs that assume that canopy carbon and moisture fluxes have the same relative response to the environment as any single leaf, simplifying the task of modeling complex landscapes. PMID:27879814

Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape.

PubMed

Glenn, Edward P; Huete, Alfredo R; Nagler, Pamela L; Nelson, Stephen G

2008-03-28

Vegetation indices (VIs) are among the oldest tools in remote sensing studies. Although many variations exist, most of them ratio the reflection of light in the red and NIR sections of the spectrum to separate the landscape into water, soil, and vegetation. Theoretical analyses and field studies have shown that VIs are near-linearly related to photosynthetically active radiation absorbed by a plant canopy, and therefore to light-dependent physiological processes, such as photosynthesis, occurring in the upper canopy. Practical studies have used time-series VIs to measure primary production and evapotranspiration, but these are limited in accuracy to that of the data used in ground truthing or calibrating the models used. VIs are also used to estimate a wide variety of other canopy attributes that are used in Soil-Vegetation-Atmosphere Transfer (SVAT), Surface Energy Balance (SEB), and Global Climate Models (GCM). These attributes include fractional vegetation cover, leaf area index, roughness lengths for turbulent transfer, emissivity and albedo. However, VIs often exhibit only moderate, non-linear relationships to these canopy attributes, compromising the accuracy of the models. We use case studies to illustrate the use and misuse of VIs, and argue for using VIs most simply as a measurement of canopy light absorption rather than as a surrogate for detailed features of canopy architecture. Used this way, VIs are compatible with "Big Leaf" SVAT and GCMs that assume that canopy carbon and moisture fluxes have the same relative response to the environment as any single leaf, simplifying the task of modeling complex landscapes.

Quality-related enzymes in fruit and vegetable products: effects of novel food processing technologies, part 1: high-pressure processing.

PubMed

Terefe, Netsanet Shiferaw; Buckow, Roman; Versteeg, Cornelis

2014-01-01

The activity of endogenous deteriorative enzymes together with microbial growth (with associated enzymatic activity) and/or other non-enzymatic (usually oxidative) reactions considerably shorten the shelf life of fruits and vegetable products. Thermal processing is commonly used by the food industry for enzyme and microbial inactivation and is generally effective in this regard. However, thermal processing may cause undesirable changes in product's sensory as well as nutritional attributes. Over the last 20 years, there has been a great deal of interest shown by both the food industry and academia in exploring alternative food processing technologies that use minimal heat and/or preservatives. One of the technologies that have been investigated in this context is high-pressure processing (HPP). This review deals with HPP focusing on its effectiveness for controlling quality-degrading enzymes in horticultural products. The scientific literature on the effects of HPP on plant enzymes, mechanism of action, and intrinsic and extrinsic factors that influence the effectiveness of HPP for controlling plant enzymes is critically reviewed. HPP inactivates vegetative microbial cells at ambient temperature conditions, resulting in a very high retention of the nutritional and sensory characteristics of the fresh product. Enzymes such as polyphenol oxidase (PPO), peroxidase (POD), and pectin methylesterase (PME) are highly resistant to HPP and are at most partially inactivated under commercially feasible conditions, although their sensitivity towards pressure depends on their origin as well as their environment. Polygalacturonase (PG) and lipoxygenase (LOX) on the other hand are relatively more pressure sensitive and can be substantially inactivated by HPP at commercially feasible conditions. The retention and activation of enzymes such as PME by HPP can be beneficially used for improving the texture and other quality attributes of processed horticultural products as well as

Powdered hide model for vegetable tanning

USDA-ARS?s Scientific Manuscript database

Powdered hide samples for this initial study of vegetable tanning were prepared from hides that were dehaired by a typical sulfide or oxidative process, and carried through the delime/bate step of a tanning process. In this study, we report on interactions of the vegetable tannin, quebracho with th...

Influence of High-Pressure Processing on the Profile of Polyglutamyl 5-Methyltetrahydrofolate in Selected Vegetables

PubMed Central

Wang, Chao; Riedl, Ken M.; Somerville, Jeremy; Balasubramaniam, V. M.; Schwartz, Steven J.

2013-01-01

In plants, folate occurs predominantly as 5-methyltetrahydrofolate (5MTHF) polyglutamyl forms. Differences in stability and bioavailability of food folate compared to synthetic folic acid have been attributed to the presence of the polyglutamyl chain. High-pressure processing (HPP) was tested for whether it might shorten polyglutamyl chains of 5MTHF species in fresh vegetables by enabling action of native γ-glutamylhydrolase (GGH). A validated ultrahigh-performance reversed-phase liquid chromatography–tandem mass spectrometry method using stable isotope as internal standard was applied for characterizing 5MTHF polyglutamyl profiles. HPP conditions included 300, 450, and 600 MPa at 30 °C for 0 or 5 min, and vegetables were vacuum-packed before treatment. Investigated vegetables included cauliflower (Brassica oleracea), baby carrots (Daucus carota), and carrot greens (D. carota). HPP treatment caused conversion of polyglutamyl 5MTHF species to short-chain and monoglutamyl forms. Maximal conversion of polyglutamyl folate to monoglutamyl folate occurred at the highest pressure/time combination investigated, 600 MPa/30 °C/5 min. Under this condition, cauliflower monoglutamyl folate increased nearly 4-fold, diglutamyl folate 32-fold, and triglutamyl folate 8-fold; carrot monoglutamyl increased 23-fold and diglutamyl 32-fold; and carrot greens monoglutamyl increased 2.5-fold and the diglutamyl form 19-fold. Although some folate degradation was observed at certain intermediate HPP conditions, total 5MTHF folate was largely preserved at 600 MPa/5 min. Thus, HPP of raw vegetables is a feasible strategy for enhancing vegetable monoglutamate 5MTHF. PMID:21770413

Antimicrobial edible films and coatings for fresh and minimally processed fruits and vegetables: a review.

PubMed

Valencia-Chamorro, Silvia A; Palou, Lluís; Del Río, Miguel A; Pérez-Gago, María B

2011-01-01

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a very active research field worldwide. Antimicrobial agents have been successfully added to edible composite films and coatings based on polysaccharides or proteins such as starch, cellulose derivatives, chitosan, alginate, fruit puree, whey protein isolated, soy protein, egg albumen, wheat gluten, or sodium caseinate. This paper reviews the development of edible films and coatings with antimicrobial activity, typically through the incorporation of antimicrobial food additives as ingredients, the effect of these edible films on the control of target microorganisms, the influence of antimicrobial agents on mechanical and barrier properties of stand-alone edible films, and the effect of the application of antimicrobial edible coatings on the quality of fresh and fresh-cut fruits and vegetables.

Modeling Hydrologic Processes after Vegetation Restoration in an Urban Watershed with HEC-HMS

NASA Astrophysics Data System (ADS)

Stevenson, K.; Kinoshita, A. M.

2017-12-01

The San Diego River Watershed in California (USA) is highly urbanized, where stream channel geomorphology are directly affected by anthropogenic disturbances. Flooding and water quality concerns have led to an increased interest in improving the condition of urban waterways. Alvarado Creek, a 1200-meter section of a tributary to the San Diego River will be used as a case study to understand the degree to which restoration efforts reduce the impacts of climate change and anthropogenic activities on hydrologic processes and water quality in urban stream ecosystems. In 2016, non-native vegetation (i.e. Washingtonia spp. (fan palm), Phoenix canariensis (Canary Island palm)) and approximately 7257 kilograms of refuse were removed from the study reach. This research develops the United States Army Corp of Engineers Hydrologic Engineering Center's Hydraulic Modeling System (USACE HEC-HMS) using field-based data to model and predict the short- and long-term impacts of restoration on geomorphic and hydrologic processes. Observations include cross-sectional area, grain-size distributions, water quality, and continuous measurements of streamflow, temperature, and precipitation. Baseline and design storms are simulated before and after restoration. The model will be calibrated and validated using field observations. The design storms represent statistical likelihoods of storms occurrences, and the pre- and post-restoration hydrologic responses will be compared to evaluate the impact of vegetation and waste removal on runoff processes. Ultimately model parameters will be transferred to other urban creeks in San Diego that may potentially undergo restoration. Modeling will be used to learn about the response trajectory of rainfall-runoff processes following restoration efforts in urban streams and guide future management and restoration activities.

Post-fire vegetation recovery in Portugal based on spot/vegetation data

NASA Astrophysics Data System (ADS)

Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

2010-04-01

A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

Evaluation of climate-related carbon turnover processes in global vegetation models for boreal and temperate forests.

PubMed

Thurner, Martin; Beer, Christian; Ciais, Philippe; Friend, Andrew D; Ito, Akihiko; Kleidon, Axel; Lomas, Mark R; Quegan, Shaun; Rademacher, Tim T; Schaphoff, Sibyll; Tum, Markus; Wiltshire, Andy; Carvalhais, Nuno

2017-08-01

Turnover concepts in state-of-the-art global vegetation models (GVMs) account for various processes, but are often highly simplified and may not include an adequate representation of the dominant processes that shape vegetation carbon turnover rates in real forest ecosystems at a large spatial scale. Here, we evaluate vegetation carbon turnover processes in GVMs participating in the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP, including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT) using estimates of vegetation carbon turnover rate (k) derived from a combination of remote sensing based products of biomass and net primary production (NPP). We find that current model limitations lead to considerable biases in the simulated biomass and in k (severe underestimations by all models except JeDi and VISIT compared to observation-based average k), likely contributing to underestimation of positive feedbacks of the northern forest carbon balance to climate change caused by changes in forest mortality. A need for improved turnover concepts related to frost damage, drought, and insect outbreaks to better reproduce observation-based spatial patterns in k is identified. As direct frost damage effects on mortality are usually not accounted for in these GVMs, simulated relationships between k and winter length in boreal forests are not consistent between different regions and strongly biased compared to the observation-based relationships. Some models show a response of k to drought in temperate forests as a result of impacts of water availability on NPP, growth efficiency or carbon balance dependent mortality as well as soil or litter moisture effects on leaf turnover or fire. However, further direct drought effects such as carbon starvation (only in HYBRID4) or hydraulic failure are usually not taken into account by the investigated GVMs. While they are considered dominant large-scale mortality agents, mortality mechanisms related to insects and

Lightning Impulse Breakdown Characteristics and Electrodynamic Process of Insulating Vegetable Oil-Based Nanofluid

NASA Astrophysics Data System (ADS)

Li, Jian; Zhang, Zhao-Tao; Zou, Ping; Du, Bin; Liao, Rui-Jin

2012-06-01

Insulating vegetable oils are considered environment-friendly and fire-resistant substitutes for insulating mineral oils. This paper presents the lightning impulse breakdown characteristic of insulating vegetable oil and insulating vegetable oil-based nanofluids. It indicates that Fe3O4 nanoparticles can increase the negative lightning impulse breakdown voltages of insulating vegetable oil by 11.8% and positive lightning impulse breakdown voltages by 37.4%. The propagation velocity of streamer is reduced by the presence of nanoparticles. The propagation velocities of streamer to positive and negative lightning impulse breakdown in the insulating vegetable oil-based nanofluids are 21.2% and 14.4% lesser than those in insulating vegetable oils, respectively. The higher electrical breakdown strength and lower streamer velocity is explained by the charging dynamics of nanoparticles in insulating vegetable oil. Space charge build-up and space charge distorted filed in point-sphere gap is also described. The field strength is reduced at the streamer tip due to the low mobility of negative nanoparticles.

Control of Aeromonas on minimally processed vegetables by decontamination with lactic acid, chlorinated water, or thyme essential oil solution.

PubMed

Uyttendaele, M; Neyts, K; Vanderswalmen, H; Notebaert, E; Debevere, J

2004-02-01

Aeromonas is an opportunistic pathogen, which, although in low numbers, may be present on minimally processed vegetables. Although the intrinsic and extrinsic factors of minimally processed prepacked vegetable mixes are not inhibitory to the growth of Aeromonas species, multiplication to high numbers during processing and storage of naturally contaminated grated carrots, mixed lettuce, and chopped bell peppers was not observed. Aeromonas was shown to be resistant towards chlorination of water, but was susceptible to 1% and 2% lactic acid and 0.5% and 1.0% thyme essential oil treatment, although the latter provoked adverse sensory properties when applied for decontamination of chopped bell peppers. Integration of a decontamination step with 2% lactic acid in the processing line of grated carrots was shown to have the potential to control the overall microbial quality of the grated carrots and was particularly effective towards Aeromonas.

[Process study on hysteresis of vegetation cover influencing sand-dust events].

PubMed

Xu, Xing-Kui; Wang, Xiao-Tao; Zhang, Feng

2009-02-15

Data analysis from satellite and weather stations during 1982-2000 shows nonlinear relationship between vegetation cover and sand-dust events is present in most part of China. Vegetation cover ratio in summer can impact significantly on the frequency of sand-dust storms from winter to spring in the source regions of sand-dust events. It is not quite clear about the hysteresis that vegetation cover in summer influence sand-dust events during winter and spring. A quasi-geostrophic barotropic model is used under the condition of 3 magnitude of frictional coefficient to investigate the cause of the hysteresis. Wind velocity shows a greatest decline at 90% during 72 h as initial wind velocity is 10 m/s for magnitude of frictional coefficient between atmosphere and water surface, greatest decline at 100% during 18 h for magnitude of frictional coefficient between atmosphere and bare soil and a 100% reduction of wind speed during 1 h for magnitude of frictional coefficient between atmosphere and vegetation cover. Observation and simulation prove that residual root and stem from summervegetation are one of factors to influence sand-dust events happened during winter and spring. Air inhibition from residual root and stem is a most important reason for hysteresis that vegetation cover influence sand-dust events.

Impact of vegetation dynamics on hydrological processes in a semi-arid basin by using a land surface-hydrology coupled model

NASA Astrophysics Data System (ADS)

Jiao, Yang; Lei, Huimin; Yang, Dawen; Huang, Maoyi; Liu, Dengfeng; Yuan, Xing

2017-08-01

Land surface models (LSMs) are widely used to understand the interactions between hydrological processes and vegetation dynamics, which is important for the attribution and prediction of regional hydrological variations. However, most LSMs have large uncertainties in their representations of eco-hydrological processes due to deficiencies in hydrological parameterizations. In this study, the Community Land Model version 4 (CLM4) LSM was modified with an advanced runoff generation and flow routing scheme, resulting in a new land surface-hydrology coupled model, CLM-GBHM. Both models were implemented in the Wudinghe River Basin (WRB), which is a semi-arid basin located in the middle reaches of the Yellow River, China. Compared with CLM, CLM-GBHM increased the Nash Sutcliffe efficiency for daily river discharge simulation (1965-1969) from -0.03 to 0.23 and reduced the relative bias in water table depth simulations (2010-2012) from 32.4% to 13.4%. The CLM-GBHM simulations with static, remotely sensed and model-predicted vegetation conditions showed that the vegetation in the WRB began to recover in the 2000s due to the Grain for Green Program but had not reached the same level of vegetation cover as regions in natural eco-hydrological equilibrium. Compared with a simulation using remotely sensed vegetation cover, the simulation with a dynamic vegetation model that considers only climate-induced change showed a 10.3% increase in evapotranspiration, a 47.8% decrease in runoff, and a 62.7% and 71.3% deceleration in changing trend of the outlet river discharge before and after the year 2000, respectively. This result suggests that both natural and anthropogenic factors should be incorporated in dynamic vegetation models to better simulate the eco-hydrological cycle.

Impact of vegetation dynamics on hydrological processes in a semi-arid basin by using a land surface-hydrology coupled model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiao, Yang; Lei, Huimin; Yang, Dawen

Land surface models (LSMs) are widely used to understand the interactions between hydrological processes and vegetation dynamics, which is important for the attribution and prediction of regional hydrological variations. However, most LSMs have large uncertainties in their representations of ecohydrological processes due to deficiencies in hydrological parameterizations. In this study, the Community Land Model version 4 (CLM4) LSM was modified with an advanced runoff generation and flow routing scheme, resulting in a new land surface-hydrology coupled model, CLM-GBHM. Both models were implemented in the Wudinghe River Basin (WRB), which is a semi-arid basin located in the middle reaches of themore » Yellow River, China. Compared with CLM, CLM-GBHM increased the Nash Sutcliffe efficiency for daily river discharge simulation (1965–1969) from 0.03 to 0.23 and reduced the relative bias in water table depth simulations (2010–2012) from 32.4% to 13.4%. The CLM-GBHM simulations with static, remotely sensed and model-predicted vegetation conditions showed that the vegetation in the WRB began to recover in the 2000s due to the Grain for Green Program but had not reached the same level of vegetation cover as regions in natural eco-hydrological equilibrium. Compared with a simulation using remotely sensed vegetation cover, the simulation with a dynamic vegetation model that considers only climate-induced change showed a 10.3% increase in evapotranspiration, a 47.8% decrease in runoff, and a 62.7% and 71.3% deceleration in changing trend of the outlet river discharge before and after the year 2000, respectively. This result suggests that both natural and anthropogenic factors should be incorporated in dynamic vegetation models to better simulate the eco-hydrological cycle.« less

Ecosystems past: prehistory of California vegetation

Treesearch

C.I. Millar; W.B. Woolfenden

2016-01-01

The history of California's vegetation, from origins in the Mesozoic through Quaternary is outlined. Climatic and geologic history and the processes driving changes in vegetation over time are also described. 

Integrated microwave processing system for the extraction of organophosphorus pesticides in fresh vegetables.

PubMed

Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

2015-03-01

A simple and efficient integrated microwave processing system (IMPS) was firstly assembled and validated for the extraction of organophosphorus pesticides in fresh vegetables. Two processes under microwave irradiation, dynamic microwave-assisted extraction (DMAE) and microwave-accelerated solvent elution (MASE), were integrated for simplifying the pretreatment of the sample. Extraction, separation, enrichment and elution were finished in a simple step. The organophosphorus pesticides were extracted from the fresh vegetables into hexane with DMAE, and then the extract was directly introduced into the enrichment column packed with active carbon fiber (ACF). Subsequently, the organophosphorus pesticides trapped on the ACF were eluted with ethyl acetate under microwave irradiation. No further filtration or cleanup was required before analysis of the eluate by gas chromatography-mass spectrometry. Some experimental parameters affecting extraction efficiency were investigated and optimized, such as microwave output power, kind and volume of extraction solvent, extraction time, amount of sorbent, elution microwave power, kind and volume of elution solvent, elution solvent flow rate. Under the optimized conditions, the recoveries were in the range of 71.5-105.2%, and the relative standard deviations were lower than 11.6%. The experiment results prove that the present method is a simple and effective sample preparation method for the determination of pesticides in solid samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of osmotic dehydration to improve fruits and vegetables quality during processing.

PubMed

Maftoonazad, Neda

2010-11-01

Osmotic treatment describes a preparation step to further processing of foods involving simultaneous transient moisture loss and solids gain when immersing in osmotic solutions, resulting in partial drying and improving the overall quality of food products. The different aspects of the osmotic dehydration (OD) technology namely the solutes employed, solutions characteristics used, process variables influence, as well as, the quality characteristics of the osmodehydrated products will be discussed in this review. As the process is carried out at mild temperatures and the moisture is removed by a liquid diffusion process, phase change that would be present in the other drying processes will be avoided, resulting in high quality products and may also lead to substantial energy savings. To optimize this process, modeling of the mass transfer phenomenon can improve high product quality. Several techniques such as microwave heating, vacuum, high pressure, pulsed electric field, etc. may be employed during or after osmotic treatment to enhance performance of the osmotic dehydration. Moreover new technologies used in osmotic dehydration will be discussed. Patents on osmotic dehydration of fruits and vegetables are also discussed in this article.

Archaeal community dynamics and abiotic characteristics in a mesophilic anaerobic co-digestion process treating fruit and vegetable processing waste sludge with chopped fresh artichoke waste.

PubMed

Ros, M; Franke-Whittle, I H; Morales, A B; Insam, H; Ayuso, M; Pascual, J A

2013-05-01

This study evaluated the feasibility of obtaining methane in anaerobic digestion (AD) from the waste products generated by the processing of fruit and vegetables. During the first phase (0-55 d) of the AD using sludge from fruit and vegetable processing, an average value of 244±88 L kg(-1) dry matter d(-1)of biogas production was obtained, and methane content reached 65% of the biogas. Co-digestion with chopped fresh artichoke wastes in a second phase (55-71 d) enhanced biogas production, and resulted in an average value of 354±68 L kg(-1) dry matter d(-1), with higher methane content (more than 70%). The archaeal community involved in methane production was studied using the ANAEROCHIP microarray and real-time PCR. Results indicated that species of Methanosaeta and Methanosarcina were important during the AD process. Methanosarcina numbers increased after the addition of chopped fresh artichoke, while Methanosaeta numbers decreased. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of the food production chain from farm practices to vegetable processing on outbreak incidence

PubMed Central

Jung, Yangjin; Jang, Hyein; Matthews, Karl R

2014-01-01

The popularity in the consumption of fresh and fresh-cut vegetables continues to increase globally. Fresh vegetables are an integral part of a healthy diet, providing vitamins, minerals, antioxidants and other health-promoting compounds. The diversity of fresh vegetables and packaging formats (spring mix in clamshell container, bagged heads of lettuce) support increased consumption. Unfortunately, vegetable production and processing practices are not sufficient to ensure complete microbial safety. This review highlights a few specific areas that require greater attention and research. Selected outbreaks are presented to emphasize the need for science-based ‘best practices’. Laboratory and field studies have focused on inactivation of pathogens associated with manure in liquid, slurry or solid forms. As production practices change, other forms and types of soil amendments are being used more prevalently. Information regarding the microbial safety of fish emulsion and pellet form of manure is limited. The topic of global climate change is controversial, but the potential effect on agriculture cannot be ignored. Changes in temperature, precipitation, humidity and wind can impact crops and the microorganisms that are associated with production environments. Climate change could potentially enhance the ability of pathogens to survive and persist in soil, water and crops, increasing human health risks. Limited research has focused on the prevalence and behaviour of viruses in pre and post-harvest environments and on vegetable commodities. Globally, viruses are a major cause of foodborne illnesses, but are seldom tested for in soil, soil amendments, manure and crops. Greater attention must also be given to the improvement in the microbial quality of seeds used in sprout production. Human pathogens associated with seeds can result in contamination of sprouts intended for human consumption, even when all appropriate ‘best practices’ are used by sprout growers. PMID

Detecting Below-Ground Processes, Diversity, and Ecosystem Function in a Savanna Ecosystem Using Spectroscopy Across Different Vegetation Layers

NASA Astrophysics Data System (ADS)

Cavender-Bares, J.; Schweiger, A. K.; Madritch, M. D.; Gamon, J. A.; Hobbie, S. E.; Montgomery, R.; Townsend, P. A.

2017-12-01

Above-and below-ground plant traits are important for substrate input to the rhizosphere. The substrate composition of the rhizosphere, in turn, affects the diversity of soil organisms, influences soil biochemistry, and water content, and resource availability for plant growth. This has substantial consequences for ecosystem functions, such as above-ground productivity and stability. Above-ground plant chemical and structural traits can be linked to the characteristics of other plant organs, including roots. Airborne imaging spectroscopy has been successfully used to model and predict chemical and structural traits of the above-ground vegetation. However, remotely sensed images capture, almost exclusively, signals from the top of the canopy, providing limited direct information about understory vegetation. Here, we use a data set collected in a savanna ecosystem consisting of spectral measurements gathered at the leaf, the whole plant, and vegetation canopy level to test for hypothesized linkages between above- and below-ground processes that influence root biomass, soil biochemistry, and the diversity of the soil community. In this environment, consisting of herbaceous vegetation intermixed with shrubs and trees growing at variable densities, we investigate the contribution of different vegetation strata to soil characteristics and test the ability of imaging spectroscopy to detect these in plant communities with contrasting vertical structure.

Thermal pasteurization of ready-to-eat foods and vegetables: Critical factors for process design and effects on quality.

PubMed

Peng, Jing; Tang, Juming; Barrett, Diane M; Sablani, Shyam S; Anderson, Nathan; Powers, Joseph R

2017-09-22

Increasing consumer desire for high quality ready-to-eat foods makes thermal pasteurization important to both food producers and researchers. To be in compliance with the Food Safety Modernization Act (FSMA), food companies seek regulatory and scientific guidelines to ensure that their products are safe. Clearly understanding the regulations for chilled or frozen foods is of fundamental importance to the design of thermal pasteurization processes for vegetables that meet food safety requirements. This article provides an overview of the current regulations and guidelines for pasteurization in the U.S. and in Europe for control of bacterial pathogens. Poorly understood viral pathogens, in terms of their survival in thermal treatments, are an increasing concern for both food safety regulators and scientists. New data on heat resistance of viruses in different foods are summarized. Food quality attributes are sensitive to thermal degradation. A review of thermal kinetics of inactivation of quality-related enzymes in vegetables and the effects of thermal pasteurization on vegetable quality is presented. The review also discusses shelf-life of thermally pasteurized vegetables.

Physiology of fresh-cut fruits and vegetables

USDA-ARS?s Scientific Manuscript database

The idea to pre-process fruits and vegetables in the fresh state started with fresh-cut salads and now has expanded to fresh-cut fruits and other vegetables. The fresh-cut portion of the fresh produce industry includes fruits, vegetables, sprouts, mushrooms and even herbs that are cut, cored, sliced...

Geomorphic predictors of riparian vegetation in small mountain watersheds

Treesearch

Blake M. Engelhardt; Jeanne C. Chambers; Peter J. Weisberg

2015-01-01

Hydrogeomorphic processes operating at watershed, process zone and site scales influence the distribution of riparian vegetation. However, most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales. We quantified the relative importance of watershed, process zone and site geomorphic characteristics...

Research in remote sensing of vegetation

NASA Technical Reports Server (NTRS)

Schrumpf, Barry J.; Ripple, William J.; Isaacson, Dennis L.

1988-01-01

The research topics undertaken were primarily selected to further the understanding of fundamental relationships between electromagnetic energy measured from Earth orbiting satellites and terrestrial features, principally vegetation. Vegetation is an essential component in the soil formation process and the major factor in protecting and holding soil in place. Vegetation plays key roles in hydrological and nutrient cycles. Awareness of improvement or deterioration in the capacity of vegetation and the trends that those changes may indicate are, therefore, critical detections to make. A study of the relationships requires consideration of the various portions of the electromagnetic spectrum; characteristics of detector system; synergism that may be achieved by merging data from two or more detector systems or multiple dates of data; and vegetational characteristics. The vegetation of Oregon is sufficiently diverse as to provide ample opportunity to investigate the relationships suggested above several vegetation types.

Monitoring vegetation phenology using MODIS

USGS Publications Warehouse

Zhang, Xiayong; Friedl, Mark A.; Schaaf, Crystal B.; Strahler, Alan H.; Hodges, John C.F.; Gao, Feng; Reed, Bradley C.; Huete, Alfredo

2003-01-01

Accurate measurements of regional to global scale vegetation dynamics (phenology) are required to improve models and understanding of inter-annual variability in terrestrial ecosystem carbon exchange and climate–biosphere interactions. Since the mid-1980s, satellite data have been used to study these processes. In this paper, a new methodology to monitor global vegetation phenology from time series of satellite data is presented. The method uses series of piecewise logistic functions, which are fit to remotely sensed vegetation index (VI) data, to represent intra-annual vegetation dynamics. Using this approach, transition dates for vegetation activity within annual time series of VI data can be determined from satellite data. The method allows vegetation dynamics to be monitored at large scales in a fashion that it is ecologically meaningful and does not require pre-smoothing of data or the use of user-defined thresholds. Preliminary results based on an annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS) data for the northeastern United States demonstrate that the method is able to monitor vegetation phenology with good success.

Effect of the chlorinated washing of minimally processed vegetables on the generation of haloacetic acids.

PubMed

Cardador, Maria Jose; Gallego, Mercedes

2012-07-25

Chlorine solutions are usually used to sanitize fruit and vegetables in the fresh-cut industry due to their efficacy, low cost, and simple use. However, disinfection byproducts such as haloacetic acids (HAAs) can be formed during this process, which can remain on minimally processed vegetables (MPVs). These compounds are toxic and/or carcinogenic and have been associated with human health risks; therefore, the U.S. Environmental Protection Agency has set a maximum contaminant level for five HAAs at 60 μg/L in drinking water. This paper describes the first method to determine the nine HAAs that can be present in MPV samples, with static headspace coupled with gas chromatography-mass spectrometry where the leaching and derivatization of the HAAs are carried out in a single step. The proposed method is sensitive, with limits of detection between 0.1 and 2.4 μg/kg and an average relative standard deviation of ∼8%. From the samples analyzed, we can conclude that about 23% of them contain at least two HAAs (<0.4-24 μg/kg), which showed that these compounds are formed during washing and then remain on the final product.

Demonstrating vegetation dynamics using SIMPPLLE

Treesearch

Glenda Scott; Jimmie D. Chew

1997-01-01

Understanding vegetation dynamics, both spatially and temporally, is essential to the management of natural resources. SIMPPLLE has been designed to help us quantify and communicate these concepts: What levels of process, i.e., fire or insect and disease, to expect; how they spread; what the vegetative distribution and composition is over time; and how silvicultural...

Effect of home food processing on chlordecone (organochlorine) content in vegetables.

PubMed

Clostre, Florence; Letourmy, Philippe; Thuriès, Laurent; Lesueur-Jannoyer, Magalie

2014-08-15

Decades after their use and their ban, organochlorine pesticides still pollute soil, water and food and lead to human and ecosystem exposure. In the case of chlordecone, human exposure is mainly due to the consumption of polluted food. We studied the effect of preparation and cooking in five vegetable products, three root vegetables (yam, dasheen and sweet potato) and two cucurbits (cucumber and pumpkin), among the main contributors to exposure to chlordecone in food in the French West Indies. Boiling the vegetables in water had no effect on chlordecone content of the vegetables and consequently on consumer exposure. The peel was three to 40-fold more contaminated than the pulp except cucumber, where the difference was less contrasted. The edible part is thus significantly less contaminated and peeling is recommended after rinsing to reduce consumer exposure, particularly for food grown in home gardens with contaminated soils. The type of soil had no consistent effect on CLD distribution but plot did. Peel and pulp composition (lipids and fibers) appear to partially account for CLD distribution in the product. Copyright © 2014 Elsevier B.V. All rights reserved.

Outcome and Process Evaluation of a Norwegian School-Randomized Fruit and Vegetable Intervention: Fruits and Vegetables Make the Marks (FVMM)

ERIC Educational Resources Information Center

Bere, E.; Veierod, M. B.; Bjelland, M.; Klepp, K.-I.

2006-01-01

This study reports the effect of the Fruits and Vegetables Make the Marks intervention, a school-based fruit and vegetable intervention consisting of a home economics classroom component and parental involvement and encouraged participation in the Norwegian School Fruit Programme, all delivered during the school year of 2001-02. Nine randomly…

Climate Change Implications to Vegetation Production in Alaska

NASA Technical Reports Server (NTRS)

Neigh, Christopher S.R.

2008-01-01

Investigation of long-term meteorological satellite data revealed statistically significant vegetation response to climate drivers of temperature, precipitation and solar radiation with exclusion of fire disturbance in Alaska. Abiotic trends were correlated to satellite remote sensing observations of normalized difference vegetation index to understand biophysical processes that could impact ecosystem carbon storage. Warming resulted in disparate trajectories for vegetation growth due to precipitation and photosynthetically active radiation variation. Interior spruce forest low lands in late summer through winter had precipitation deficit which resulted in extensive fire disturbance and browning of undisturbed vegetation with reduced post-fire recovery while Northern slope moist alpine tundra had increased production due to warmer-wetter conditions during the late 1990s and early 2000s. Coupled investigation of Alaska s vegetation response to warming climate found spatially dynamic abiotic processes with vegetation browning not a result from increased fire disturbance.

Assembly processes under severe abiotic filtering: adaptation mechanisms of weed vegetation to the gradient of soil constraints.

PubMed

Nikolic, Nina; Böcker, Reinhard; Kostic-Kravljanac, Ljiljana; Nikolic, Miroslav

2014-01-01

Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response? Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate. We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale). The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio. Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations of species which are typically observed as a

Assembly Processes under Severe Abiotic Filtering: Adaptation Mechanisms of Weed Vegetation to the Gradient of Soil Constraints

PubMed Central

Nikolic, Nina; Böcker, Reinhard; Kostic-Kravljanac, Ljiljana; Nikolic, Miroslav

2014-01-01

Questions Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response? Location Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate. Methods We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale). Results The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio. Conclusion Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations

Integrating Vegetation Classification, Mapping, and Strategic Inventory for Forest Management

Treesearch

C. K. Brewer; R. Bush; D. Berglund; J. A. Barber; S. R. Brown

2006-01-01

Many of the analyses needed to address multiple resource issues are focused on vegetation pattern and process relationships and most rely on the data models produced from vegetation classification, mapping, and/or inventory. The Northern Region Vegetation Mapping Project (R1-VMP) data models are based on these three integrally related, yet separate processes. This...

MC1: a dynamic vegetation model for estimating the distribution of vegetation and associated carbon, nutrients, and water—technical documentation. Version 1.0.

Treesearch

Dominique Bachelet; James M. Lenihan; Christopher Daly; Ronald P. Neilson; Dennis S. Ojima; William J. Parton

2001-01-01

Assessments of vegetation response to climate change have generally been made only by equilibrium vegetation models that predict vegetation composition under steady-state conditions. These models do not simulate either ecosystem biogeochemical processes or changes in ecosystem structure that may, in turn, act as feedbacks in determining the dynamics of vegetation...

Effect of processing methods on the nutritional content of three traditional vegetables leaves: Amaranth, black nightshade and jute mallow.

PubMed

Traoré, Korotimi; Parkouda, Charles; Savadogo, Aly; Ba/Hama, Fatoumata; Kamga, Regine; Traoré, Yves

2017-11-01

The study assessed changes in nutritional content of some commonly consumed traditional vegetables subjected to postharvest processes. Amaranth ( Amaranthus cruentus L.), black nightshade ( Solanum scabrum Mill.) and jute mallow ( Corchorus olitorius L.) leaves used as vegetables were subjected to blanching, boiling and drying. The proximate composition and β-carotene content of fresh and processed leaves were determined. Amaranth, black nightshade and jute mallow leaves had 25.21%, 39.74% and 29.18% of protein, respectively. The β-carotene levels were 16.40, 25.25 and 27.74 mg/100 g for black nightshade amaranth and jute mallow leaves, respectively. The ash content was 10.57% for black nightshade, 12.40% for jute mallow and 16.33% for amaranth. Processing methods caused decreases of β-carotene and crude lipid content. Boiling for 30 min or more resulted in large loss of β-carotene. Drying under shade resulted in less loss of β-carotene than drying in cabinet at 50 and 60°C.

Evaluation of DGVMs in tropical areas: linking patterns of vegetation cover, climate and fire to ecological processes

NASA Astrophysics Data System (ADS)

D'Onofrio, Donatella; von Hardenberg, Jost; Baudena, Mara

2017-04-01

Many current Dynamic Global Vegetation Models (DGVMs), including those incorporated into Earth System Models (ESMs), are able to realistically reproduce the distribution of the most worldwide biomes. However, they display high uncertainty in predicting the forest, savanna and grassland distributions and the transitions between them in tropical areas. These biomes are the most productive terrestrial ecosystems, and owing to their different biogeophysical and biogeochemical characteristics, future changes in their distributions could have also impacts on climate states. In particular, expected increasing temperature and CO2, modified precipitation regimes, as well as increasing land-use intensity could have large impacts on global biogeochemical cycles and precipitation, affecting the land-climate interactions. The difficulty of the DGVMs in simulating tropical vegetation, especially savanna structure and occurrence, has been associated with the way they represent the ecological processes and feedbacks between biotic and abiotic conditions. The inclusion of appropriate ecological mechanisms under present climatic conditions is essential for obtaining reliable future projections of vegetation and climate states. In this work we analyse observed relationships of tree and grass cover with climate and fire, and the current ecological understanding of the mechanisms driving the forest-savanna-grassland transition in Africa to evaluate the outcomes of a current state-of-the-art DGVM and to assess which ecological processes need to be included or improved within the model. Specifically, we analyse patterns of woody and herbaceous cover and fire return times from MODIS satellite observations, rainfall annual average and seasonality from TRMM satellite measurements and tree phenology information from the ESA global land cover map, comparing them with the outcomes of the LPJ-GUESS DGVM, also used by the EC-Earth global climate model. The comparison analysis with the LPJ

Health status of birds fed diets containing three differently processed discarded vegetable-bovine blood-rumen content mixtures.

PubMed

Ekunseitan, D A; Balogun, O O; Sogunle, O M; Yusuf, A O; Ayoola, A A; Egbeyale, L T; Adeyemi, O A; Allison, I B; Iyanda, A I

2013-04-01

This study was conducted to determine the effect of feeding three differently processed mixtures on health status of broilers. A total of 1080 day-old Marshal broilers were fed; discarded vegetable-fresh bovine blood-fresh rumen digesta (P1), discarded vegetable-ensiled bovine blood-fresh rumen digesta (P2) and discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3) at three levels of inclusion (0, 3 and 6%). Data on blood parameters was taken and were subjected to 3 x 3 factorial arrangements in a completely randomized design. Birds fed P1 had least values (p < 0.05) of serum glucose, total protein, globulin, uric acid and creatinine at starter phase. Birds fed diets containing 3 and 6% level of inclusion recorded the highest (p < 0.05) Packed cell volume, Haemoglobin, White blood cell and Red blood cell values. However, those fed at 0% level of inclusion recorded the highest albumin value. At finisher phase, birds fed P2 and P3 had the highest glucose, uric acid and creatinine values. 6% level of inclusion significantly (p < 0.05) increased the total protein and albumin values. Therefore, for enhanced performance and without comprising the health condition of birds; broiler chickens could be fed diets containing discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3) up to 6% level of inclusion.

Microbial-processing of fruit and vegetable wastes for production of vital enzymes and organic acids: Biotechnology and scopes.

PubMed

Panda, Sandeep K; Mishra, Swati S; Kayitesi, Eugenie; Ray, Ramesh C

2016-04-01

Wastes generated from fruits and vegetables are organic in nature and contribute a major share in soil and water pollution. Also, green house gas emission caused by fruit and vegetable wastes (FVWs) is a matter of serious environmental concern. This review addresses the developments over the last one decade on microbial processing technologies for production of enzymes and organic acids from FVWs. The advances in genetic engineering for improvement of microbial strains in order to enhance the production of the value added bio-products as well as the concept of zero-waste economy have been briefly discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

[Review of dynamic global vegetation models (DGVMs)].

PubMed

Che, Ming-Liang; Chen, Bao-Zhang; Wang, Ying; Guo, Xiang-Yun

2014-01-01

Dynamic global vegetation model (DGVM) is an important and efficient tool for study on the terrestrial carbon circle processes and vegetation dynamics. This paper reviewed the development history of DGVMs, introduced the basic structure of DGVMs, and the outlines of several world-widely used DGVMs, including CLM-DGVM, LPJ, IBIS and SEIB. The shortages of the description of dynamic vegetation mechanisms in the current DGVMs were proposed, including plant functional types (PFT) scheme, vegetation competition, disturbance, and phenology. Then the future research directions of DGVMs were pointed out, i. e. improving the PFT scheme, refining the vegetation dynamic mechanism, and implementing a model inter-comparison project.

Building the United States National Vegetation Classification

USGS Publications Warehouse

Franklin, S.B.; Faber-Langendoen, D.; Jennings, M.; Keeler-Wolf, T.; Loucks, O.; Peet, R.; Roberts, D.; McKerrow, A.

2012-01-01

The Federal Geographic Data Committee (FGDC) Vegetation Subcommittee, the Ecological Society of America Panel on Vegetation Classification, and NatureServe have worked together to develop the United States National Vegetation Classification (USNVC). The current standard was accepted in 2008 and fosters consistency across Federal agencies and non-federal partners for the description of each vegetation concept and its hierarchical classification. The USNVC is structured as a dynamic standard, where changes to types at any level may be proposed at any time as new information comes in. But, because much information already exists from previous work, the NVC partners first established methods for screening existing types to determine their acceptability with respect to the 2008 standard. Current efforts include a screening process to assign confidence to Association and Group level descriptions, and a review of the upper three levels of the classification. For the upper levels especially, the expectation is that the review process includes international scientists. Immediate future efforts include the review of remaining levels and the development of a proposal review process.

Stereophotogrammetry in studies of riparian vegetation dynamics

NASA Astrophysics Data System (ADS)

Hortobagyi, Borbala; Vautier, Franck; Corenblit, Dov; Steiger, Johannes

2014-05-01

Riparian vegetation responds to hydrogeomorphic disturbances and also controls sediment deposition and erosion. Spatio-temporal riparian vegetation dynamics within fluvial corridors have been quantified in many studies using aerial photographs and GIS. However, this approach does not allow the consideration of woody vegetation growth rates (i.e. vertical dimension) which are fundamental when studying feedbacks between the processes of fluvial landform construction and vegetation establishment and succession. We built 3D photogrammetric models of vegetation height based on aerial argentic and digital photographs from sites of the Allier and Garonne Rivers (France). The models were realized at two different spatial scales and with two different methods. The "large" scale corresponds to the reach of the river corridor on the Allier river (photograph taken in 2009) and the "small" scale to river bars of the Allier (photographs taken in 2002, 2009) and Garonne Rivers (photographs taken in 2000, 2002, 2006 and 2010). At the corridor scale, we generated vegetation height models using an automatic procedure. This method is fast but can only be used with digital photographs. At the bar scale, we constructed the models manually using a 3D visualization on the screen. This technique showed good results for digital and also argentic photographs but is very time-consuming. A diachronic study was performed in order to investigate vegetation succession by distinguishing three different classes according to the vegetation height: herbs (<1 m), shrubs (1-4 m) or trees (>4 m). Both methods, i.e. automatic and manual, were employed to study the evolution of the three vegetation classes and the recruitment of new vegetation patches. A comparison was conducted between the vegetation height given by models (automatic and manual) and the vegetation height measured in the field. The manually produced models (small scale) were of a precision of 0.5-1 m, allowing the quantification of woody

Importance of vegetation distribution for future carbon balance

NASA Astrophysics Data System (ADS)

Ahlström, A.; Xia, J.; Arneth, A.; Luo, Y.; Smith, B.

2015-12-01

Projections of future terrestrial carbon uptake vary greatly between simulations. Net primary production (NPP), wild fires, vegetation dynamics (including biome shifts) and soil decomposition constitute the main processes governing the response of the terrestrial carbon cycle in a changing climate. While primary production and soil respiration are relatively well studied and implemented in all global ecosystem models used to project the future land sink of CO2, vegetation dynamics are less studied and not always represented in global models. Here we used a detailed second generation dynamic global vegetation model with advanced representation of vegetation growth and mortality and the associated turnover and proven skill in predicting vegetation distribution and succession. We apply an emulator that describes the carbon flows and pools exactly as in simulations with the full model. The emulator simulates ecosystem dynamics in response to 13 different climate or Earth system model simulations from the CMIP5 ensemble under RCP8.5 radiative forcing at year 2085. We exchanged carbon cycle processes between these 13 simulations and investigate the changes predicted by the emulator. This method allowed us to partition the entire ensemble carbon uptake uncertainty into individual processes. We found that NPP, vegetation dynamics (including biome shifts, wild fires and mortality) and soil decomposition rates explained 49%, 17% and 33% respectively of uncertainties in modeled global C-uptake. Uncertainty due to vegetation dynamics was further partitioned into stand-clearing disturbances (16%), wild fires (0%), stand dynamics (7%), reproduction (10%) and biome shifts (67%) globally. We conclude that while NPP and soil decomposition rates jointly account for 83% of future climate induced C-uptake uncertainties, vegetation turnover and structure, dominated by shifts in vegetation distribution, represent a significant fraction globally and regionally (tropical forests: 40

Vegetation ecogeomorphology, dynamic equilibrium, and disturbance: chapter 7

USGS Publications Warehouse

Hupp, Cliff R.

2013-01-01

Early ecologists understood the need to document geomorphic form and process to explain plant species distributions. Although this relationship has been acknowledged for over a century, with the exception of a few landmark papers, only the past few decades have experienced intensive research on this interdisciplinary topic. Here the authors provide a summary of the intimate relations between vegetation and geomorphic/process on hillslopes and fluvial systems. These relations are separated into systems (primarily fluvial) in dynamic equilibrium and those that are in nonequilibrium conditions including the impacts of various human disturbances affecting landforms, geomorphic processes, and interrelated, attendant vegetation patterns and processes. The authors conclude with a conceptual model of stream regime focusing on sediment deposition, erosion, and equilibrium that can be expanded to organize and predict vegetation patterns and life history strategies.

7 CFR 52.38c - Statistical sampling procedures for lot inspection of processed fruits and vegetables by attributes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Statistical sampling procedures for lot inspection of processed fruits and vegetables by attributes. 52.38c Section 52.38c Agriculture Regulations of the... Regulations Governing Inspection and Certification Sampling § 52.38c Statistical sampling procedures for lot...

7 CFR 52.38c - Statistical sampling procedures for lot inspection of processed fruits and vegetables by attributes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Statistical sampling procedures for lot inspection of processed fruits and vegetables by attributes. 52.38c Section 52.38c Agriculture Regulations of the... Regulations Governing Inspection and Certification Sampling § 52.38c Statistical sampling procedures for lot...

Simulation of Dynamic Soil Crusting Processes and Vegetative Feedbacks in Semi-Arid Regions

NASA Astrophysics Data System (ADS)

Sivandran, G.; Bras, R. L.

2009-12-01

Many soils, especially those in arid and semi-arid regions, develop compacted surface layers with hydrologic properties different to those of the underlying layers. These layers, referred to as soil crusts when dry and soil seals when wet, may be only a few millimeters thick but can have a significant impact by altering the partitioning of rainfall, increasing surface runoff and reducing infiltration. This reduces the quantity of water entering the root zone, limiting the amount of water available for primary productivity, while increasing erosion and negatively impacting seedling establishment and growth. Vegetation significantly alters soil hydraulic properties in the immediate vicinity of a vegetation patch. Root action has been shown to create macropores, increasing infiltration capacity around the base of vegetation. Shading protects the soil from evaporation and the formation of soil seals/crusts. Experiments have confirmed large variations in infiltration rates in below canopy and bare soil patches. It is believed that a positive feedback may occur between seals/crusts and vegetation patches resulting in systems that exhibit ‘islands of fertility’. The bare soil patches act to increase the micro-catchment area of the vegetation patch, thereby collecting moisture from a far greater area than the immediate footprint of its rooting system. Vegetation then alters the soil conditions directly beneath it, allowing for increased infiltration of this extra moisture. A coupled, dynamic vegetation and hydrologic model, tRIBS+VEGGIE, was used to explore the role of dynamic soil properties on hydrologic and energy fluxes. Rather than assigning the hydraulic properties of the surface soils a priori, soil seals/crusts were allowed to develop in the model depending on vegetation cover, soil type and rainfall intensity. The effects of plant shading and root action on infiltration in the immediate vicinity of vegetation patches were also included. These changes

Probabilistic Evaluation of Anthropogenic Regulations In a Vegetated River Channel Using a Vegetation Dynamics Modeling

NASA Astrophysics Data System (ADS)

Miyamoto, Hitoshi

2015-04-01

Vegetation overgrowth in fluvial floodplains, gravel beds, and sand bars has been a serious engineering problem for riparian management in Japan. From the viewpoints of flood control and ecological conservation, it would be necessary to predict the vegetation dynamics accurately for long-term duration. In this research, we have developed a stochastic model for predicting the vegetation dynamics in fluvial floodplains with emphasis on the interaction with flood impacts. The model consists of the following four components: (i) long-term stochastic behavior of flow discharge, (ii) hydrodynamics in a channel with floodplain vegetation, (iii) variation of riverbed topography, and (iv) vegetation dynamics on floodplains. In the vegetation dynamics model, the flood discharge (i) is stochastically simulated using a filtered Poisson process, one of the conventional approaches in hydrological time-series generation. The component for vegetation dynamics (iv) includes the effects of tree growth, mortality by floods, and infant tree recruitment. Vegetation condition has been observed mainly before and after floods since 2008 at a field site located between 23-24 km from the river mouth in Kako River, Japan. The Kako River has the catchment area of 1,730 km2 and the main channel length of 96 km. This site is one of the vegetation overgrowth sites in the Kako River floodplains. The predominant tree species are willows and bamboos. In the field survey, the position, trunk diameter and height of each tree as well as the riverbed materials were measured after several flood events to investigate their impacts on the floodplain vegetation community. This presentation tries to examine effects of anthropogenic river regulations, i.e., thinning and cutting-down, in the vegetated channel in Kako River by using the vegetation dynamics model. Sensitivity of both the flood water level and the vegetation status in the channel is statistically evaluated in terms of the different cutting

[Examination of processed vegetable foods for the presence of common DNA sequences of genetically modified tomatoes].

PubMed

Kitagawa, Mamiko; Nakamura, Kosuke; Kondo, Kazunari; Ubukata, Shoji; Akiyama, Hiroshi

2014-01-01

The contamination of processed vegetable foods with genetically modified tomatoes was investigated by the use of qualitative PCR methods to detect the cauliflower mosaic virus 35S promoter (P35S) and the kanamycin resistance gene (NPTII). DNA fragments of P35S and NPTII were detected in vegetable juice samples, possibly due to contamination with the genomes of cauliflower mosaic virus infecting juice ingredients of Brassica species and soil bacteria, respectively. Therefore, to detect the transformation construct sequences of GM tomatoes, primer pairs were designed for qualitative PCR to specifically detect the border region between P35S and NPTII, and the border region between nopaline synthase gene promoter and NPTII. No amplification of the targeted sequences was observed using genomic DNA purified from the juice ingredients. The developed qualitative PCR method is considered to be a reliable tool to check contamination of products with GM tomatoes.

Effects of Near Soil Surface Characteristics on the Soil Detachment Process in a Chronological Series of Vegetation Restoration

NASA Astrophysics Data System (ADS)

Wang, Bing

2017-04-01

The effects of near soil surface characteristics on the soil detachment process might be different at different stages of vegetation restoration. This study was performed to investigate the effects of the near soil surface factors of plant litter, biological soil crusts (BSCs), dead roots and live roots on the soil detachment process by overland flow at different stages of restoration. Soil samples (1 m long, 0.1 m wide, and 0.05 m high) under four treatment conditions were collected from 1-yr-old and 24-yr-old natural grasslands and subjected to flow scouring under five different shear stresses ranging from 5.3 to 14.6 Pa. The results indicated that the effects of near soil surface characteristics on soil detachment were substantial during the process of vegetation restoration. The total reduction in the soil detachment capacity of the 1-yr-old grassland was 98.1%, and of this total, 7.9%, 30.0% and 60.2% was attributed to the litter, BSCs and plant roots, respectively. In the 24-yr-old grassland, the soil detachment capacity decreased by 99.0%, of which 13.2%, 23.5% and 62.3% was caused by the litter, BSCs and plant roots, respectively. Combined with the previously published data of a 7-yr-old grassland, the influence of plant litter on soil detachment was demonstrated to increase with restoration time, but soil detachment was also affected by the litter type and composition. The role of BSCs was greater than that of plant litter in reducing soil detachment during the early stages of vegetation recovery. However, its contribution weakened with time since restoration. The influence of plant roots accounted for at least half or up to two-thirds of the total near soil surface factors, of which more than 72.6% was attributed to the physical binding effects of the roots. The chemical bonding effect of the roots increased with time since restoration and was greater than the effect of the litter on soil detachment in the late stages of vegetation restoration. The

Contamination pathways of spore-forming bacteria in a vegetable cannery.

PubMed

Durand, Loïc; Planchon, Stella; Guinebretiere, Marie-Hélène; André, Stéphane; Carlin, Frédéric; Remize, Fabienne

2015-06-02

Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery. Copyright © 2015 Elsevier B.V. All rights reserved.

A Reference Unit on Home Vegetable Gardening.

ERIC Educational Resources Information Center

McCully, James S., Comp.; And Others

Designed to provide practical, up-to-date, basic information on home gardening for vocational agriculture students with only a limited knowledge of vegetable gardening, this reference unit includes step-by-step procedures for planning, planting, cultivating, harvesting, and processing vegetables in a small plot. Topics covered include plot…

State of polyphenols in the drying process of fruits and vegetables.

PubMed

McSweeney, M; Seetharaman, K

2015-01-01

This review presents an overview of drying technologies and its impact on the polyphenol content of vegetables and fruits. Polyphenols contribute to many health benefits and can act as antioxidants. Specifically an increased intake of polyphenols has been shown to decrease the incidence of cardiovascular disease; furthermore, it has been shown to help reduce the risk of neurodegenerative diseases in humans. Many researchers have reported on the effect of different drying techniques on the polyphenol content in fruits and vegetables. Polyphenol degradation mechanisms proposed in literature and pretreatments that potentially lead to higher retention of polyphenols during drying are also discussed.

Inter-species competition-facilitation in stochastic riparian vegetation dynamics.

PubMed

Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

2013-02-07

Riparian vegetation is a highly dynamic community that lives on river banks and which depends to a great extent on the fluvial hydrology. The stochasticity of the discharge and erosion/deposition processes in fact play a key role in determining the distribution of vegetation along a riparian transect. These abiotic processes interact with biotic competition/facilitation mechanisms, such as plant competition for light, water, and nutrients. In this work, we focus on the dynamics of plants characterized by three components: (1) stochastic forcing due to river discharges, (2) competition for resources, and (3) inter-species facilitation due to the interplay between vegetation and fluid dynamics processes. A minimalist stochastic bio-hydrological model is proposed for the dynamics of the biomass of two vegetation species: one species is assumed dominant and slow-growing, the other is subdominant, but fast-growing. The stochastic model is solved analytically and the probability density function of the plant biomasses is obtained as a function of both the hydrologic and biologic parameters. The impact of the competition/facilitation processes on the distribution of vegetation species along the riparian transect is investigated and remarkable effects are observed. Finally, a good qualitative agreement is found between the model results and field data. Copyright © 2012 Elsevier Ltd. All rights reserved.

Toward a comprehensive landscape vegetation monitoring framework

NASA Astrophysics Data System (ADS)

Kennedy, Robert; Hughes, Joseph; Neeti, Neeti; Larrue, Tara; Gregory, Matthew; Roberts, Heather; Ohmann, Janet; Kane, Van; Kane, Jonathan; Hooper, Sam; Nelson, Peder; Cohen, Warren; Yang, Zhiqiang

2016-04-01

Blossoming Earth observation resources provide great opportunity to better understand land vegetation dynamics, but also require new techniques and frameworks to exploit their potential. Here, I describe several parallel projects that leverage time-series Landsat imagery to describe vegetation dynamics at regional and continental scales. At the core of these projects are the LandTrendr algorithms, which distill time-series earth observation data into periods of consistent long or short-duration dynamics. In one approach, we built an integrated, empirical framework to blend these algorithmically-processed time-series data with field data and lidar data to ascribe yearly change in forest biomass across the US states of Washington, Oregon, and California. In a separate project, we expanded from forest-only monitoring to full landscape land cover monitoring over the same regional scale, including both categorical class labels and continuous-field estimates. In these and other projects, we apply machine-learning approaches to ascribe all changes in vegetation to driving processes such as harvest, fire, urbanization, etc., allowing full description of both disturbance and recovery processes and drivers. Finally, we are moving toward extension of these same techniques to continental and eventually global scales using Google Earth Engine. Taken together, these approaches provide one framework for describing and understanding processes of change in vegetation communities at broad scales.

The role of vegetation in shaping dune morphology

NASA Astrophysics Data System (ADS)

Duran Vinent, O.; Moore, L. J.; Young, D.

2012-12-01

Aeolian dunes naturally emerge under strong winds and sufficient sand supply. They represent the most dynamical feature of the arid and/or coastal landscape and their evolution has the potential to either increase desertification or reduce coastal vulnerability to storms. Although large-scale dune morphology mainly depends on the wind regime and sand availability, vegetation plays an important role in semiarid and/or coastal areas. It is well known that under certain conditions vegetation is able to stabilize dunes, driving a morphological transformation from un-vegetated mobile crescent dunes to static vegetated "parabolic" dunes, de facto paralyzing desertification and initiating land recovery. Furthermore, vegetation is also the primary ingredient in the formation of coastal foredunes, which determine vulnerability to storms, as low dunes are prone to storm-induced erosion and overwash. In both cases, the coupling of biological and geomorphic (physical) processes, in particular vegetation growth and sand transport, governs the evolution of morphology. These processes were implemented in a computational model as part of a previous effort. It was shown that, for a migrating dune, this coupling leads to a negative feedback for dune motion, where an ever denser vegetation implies ever lesser sand transport. The model also predicted the existence of a "mobility index", defined by the vegetation growth rate to sand erosion rate ratio, that fully characterizes the morphological outcome: for indices above a certain threshold biological processes are dominant and dune motion slows after being covered by plants; for lower indices, the physical processes are the dominant ones and the dune remains mobile while vegetation is buried or rooted out. Here, we extend this model to better understand the formation of coastal dunes. We include new physical elements such as the shoreline and water table, as well as different grass species and potential competition among them

The contribution of brown vegetation to vegetation dynamics

USDA-ARS?s Scientific Manuscript database

Indices of vegetation dynamics that include both green vegetation (GV) and non-photosynthetic vegetation (NPV), that is, brown vegetation, were applied to MODIS surface reflectance data from 2000 to 2006 for the southwestern United States. These indices reveal that the cover of NPV, a measure of veg...

Effects of future climate change, CO2 enrichment, and vegetation structure variation on hydrological processes in China

USGS Publications Warehouse

Zhu, Qiuan; Jiang, Hong; Peng, Changhui; Liu, Jinxun; Fang, Xiuqin; Wei, Xiaohua; Liu, Shirong; Zhou, Guomo

2012-01-01

Investigating the relationship between factors (climate change, atmospheric CO2 concentrations enrichment, and vegetation structure) and hydrological processes is important for understanding and predicting the interaction between the hydrosphere and biosphere. The Integrated Biosphere Simulator (IBIS) was used to evaluate the effects of climate change, rising CO2, and vegetation structure on hydrological processes in China at the end of the 21st century. Seven simulations were implemented using the assemblage of the IPCC climate and CO2 concentration scenarios, SRES A2 and SRES B1. Analysis results suggest that (1) climate change will have increasing effects on runoff, evapotranspiration (ET), transpiration (T), and transpiration ratio (transpiration/evapotranspiration, T/E) in most hydrological regions of China except in the southernmost regions; (2) elevated CO2 concentrations will have increasing effects on runoff at the national scale, but at the hydrological region scale, the physiology effects induced by elevated CO2 concentration will depend on the vegetation types, climate conditions, and geographical background information with noticeable decreasing effects shown in the arid Inland region of China; (3) leaf area index (LAI) compensation effect and stomatal closure effect are the dominant factors on runoff in the arid Inland region and southern moist hydrological regions, respectively; (4) the magnitudes of climate change (especially the changing precipitation pattern) effects on the water cycle are much larger than those of the elevated CO2 concentration effects; however, increasing CO2 concentration will be one of the most important modifiers to the water cycle; (5) the water resource condition will be improved in northern China but depressed in southernmost China under the IPCC climate change scenarios, SRES A2 and SRES B1.

Vegetation Impacts on Near Bank Flows

NASA Astrophysics Data System (ADS)

Hopkinson, L. C.; Wynn, T. M.

2008-12-01

Sediment, a leading cause of water quality impairment, damages aquatic ecosystems and interferes with recreational uses and water treatment processes. A significant sediment source to streams, streambank retreat, has largely been ignored. Vegetation is an important component of stream restoration designs used to control streambank retreat, but vegetation effects on near bank flows need to be quantified. The goal of this research is to evaluate the effects of streambank vegetation on near bank flows and boundary shear stress. A flume experiment was conducted comparing three distinct streambank vegetation types: trees, shrubs, and grass. A second order prototype stream (Tom's Creek in Blacksburg, VA), with individual reaches dominated by the vegetation treatments was modeled using a fixed-bed Froude-scale modeling technique. One model streambank of the prototype stream was constructed for each vegetation type and compared to a bare control (only grain roughness). Simulated vegetation (e.g. woven grass mat and wooden dowels) was attached in locations identified in a field survey. Velocity profiles perpendicular to the flume model boundary will be evaluated along five cross sections for each vegetation treatment. Reynolds, law of the wall, and turbulent kinetic energy shear stresses will be analyzed using velocity measurements made with a three-dimensional acoustic Doppler velocimeter (ADV). Velocity profiles perpendicular to the flume model streambank will also be evaluated. The velocity profiles will be compared among vegetation types to see if profiles are similar along the bank face. This research is intended to improve our understanding of the role of riparian vegetation in stream morphology by evaluating the effects of vegetation on boundary shear stress, providing insight to the type and density of vegetation required for streambank stability. The results will also aide in quantifying sediment inputs from streambanks, providing quantitative information for

Microbiological quality of fresh, minimally-processed fruit and vegetables, and sprouts from retail establishments.

PubMed

Abadias, M; Usall, J; Anguera, M; Solsona, C; Viñas, I

2008-03-31

A survey of fresh and minimally-processed fruit and vegetables, and sprouts was conducted in several retail establishments in the Lleida area (Catalonia, Spain) during 2005-2006 to determine whether microbial contamination, and in particular potentially pathogenic bacteria, was present under these commodities. A total of 300 samples--including 21 ready-to-eat fruits, 28 whole fresh vegetables, 15 sprout samples and 237 ready-to-eat salads containing from one to six vegetables--were purchased from 4 supermarkets. They were tested for mesophilic and psychrotrophic aerobic counts, yeasts and moulds, lactic acid bacteria, Enterobacteriaceae, presumptive E. coli and Listeria monocytogenes counts as well as for the presence of Salmonella, E. coli O157:H7, Yersinia enterocolitica and thermotolerant Campylobacter. Results for the fresh-cut vegetables that we analyzed showed that, in general, the highest microorganism counts were associated with grated carrot, arugula and spinach (7.8, 7.5 and 7.4 log cfu g(-1) of aerobic mesophilic microorganisms; 6.1, 5.8 and 5.2 log cfu g(-1) of yeast and moulds; 5.9, 4.0 and 5.1 log cfu g(-1) lactic acid bacteria and 6.2, 5.3 and 6.0 log cfu g(-1) of Enterobacteriaceae). The lowest counts were generally associated with fresh-cut endive and lettuce (6.2 and 6.3 log cfu g(-1) of aerobic mesophilic microorganisms; 4.4 and 4.6 log cfu g(-1) of yeast and moulds; 2.7 and 3.8 log cfu g(-1) lactic acid bacteria and 4.8 and 4.4 log cfu g(-1) of Enterobacteriaceae). Counts of psychrotrophic microorganisms were as high as those of mesophilic microorganisms. Microbiological counts for fresh-cut fruit were very low. Sprouts were highly contaminated with mesophilic (7.9 log cfu g(-1)), psychrotrophic microorganisms (7.3 log cfu g(-1)) and Enterobacteriaceae (7.2 log cfu g(-1)) and showed a high incidence of E. coli (40% of samples). Of the samples analyzed, four (1.3%) were Salmonella positive and two (0.7%) harboured L. monocytogenes. None of the

Family members' influence on family meal vegetable choices

PubMed Central

Wenrich, Tionni R.; Brown, J. Lynne; Miller-Day, Michelle; Kelley, Kevin J.; Lengerich, Eugene J.

2010-01-01

Objective Characterize the process of family vegetable selection (especially cruciferous, deep orange, and dark green leafy vegetables); demonstrate the usefulness of Exchange Theory (how family norms and past experiences interact with rewards and costs) for interpreting the data. Design Eight focus groups, two with each segment (men/women vegetable-likers/dislikers based on a screening form). Participants completed a vegetable intake form. Setting Rural Appalachian Pennsylvania. Participants 61 low-income, married/cohabiting men (n=28) and women (n=33). Analysis Thematic analysis within Exchange Theory framework for qualitative data. Descriptive analysis, t-tests and chi-square tests for quantitative data. Results Exchange Theory proved useful for understanding that regardless of sex or vegetable-liker/disliker status, meal preparers see more costs than rewards to serving vegetables. Past experience plus expectations of food preparer role and of deference to family member preferences supported a family norm of serving only vegetables acceptable to everyone. Emphasized vegetables are largely ignored due to unfamiliarity; family norms prevented experimentation and learning through exposure. Conclusions and Implications Interventions to increase vegetable consumption of this audience could 1) alter family norms about vegetables served, 2) change perceptions of past experiences, 3) reduce social and personal costs of serving vegetables and 4) increase tangible and social rewards of serving vegetables. PMID:20452288

Thermal, High Pressure, and Electric Field Processing Effects on Plant Cell Membrane Integrity and Relevance to Fruit and Vegetable Quality

PubMed Central

Gonzalez, Maria E; Barrett, Diane M

2010-01-01

Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (1H-NMR). PMID:20492210

Thermal, high pressure, and electric field processing effects on plant cell membrane integrity and relevance to fruit and vegetable quality.

PubMed

Gonzalez, Maria E; Barrett, Diane M

2010-09-01

Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (¹H-NMR).

The Hydromechanics of Vegetation for Slope Stabilization

NASA Astrophysics Data System (ADS)

Mulyono, A.; Subardja, A.; Ekasari, I.; Lailati, M.; Sudirja, R.; Ningrum, W.

2018-02-01

Vegetation is one of the alternative technologies in the prevention of shallow landslide prevention that occurs mostly during the rainy season. The application of plant for slope stabilization is known as bioengineering. Knowledge of the vegetative contribution that can be considered in bioengineering was the hydrological and mechanical aspects (hydromechanical). Hydrological effect of the plant on slope stability is to reduce soil water content through transpiration, interception, and evapotranspiration. The mechanical impact of vegetation on slope stability is to stabilize the slope with mechanical reinforcement of soils through roots. Vegetation water consumption varies depending on the age and density, rainfall factors and soil types. Vegetation with high ability to absorb water from the soil and release into the atmosphere through a transpiration process will reduce the pore water stress and increase slope stability, and vegetation with deep root anchoring and strong root binding was potentially more significant to maintain the stability of the slope.

Vegetation Description, Rare Plant Inventory, and Vegetation Monitoring for Craig Mountain, Idaho.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mancuso, Michael; Moseley, Robert

The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston,more » Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals.« less

Effect of hydrothermal processing on total polyphenolics and antioxidant potential of underutilized leafy vegetables, Boerhaavia diffusa and Portulaca oleracea

PubMed Central

Nagarani, Gunasekaran; Abirami, Arumugam; Nikitha, Prasad; Siddhuraju, Perumal

2014-01-01

Objective To investigate the effect of different processing methods on antioxidant properties of acetone extract of aerial parts from Boerhaavia diffusa and Portulaca oleracea. Methods The total phenolic and flavonoid contents were determined by Folin-Ciocalteau and aluminum chloride method, respectively. FRAP, metal chelating activity, DPPH, ABTS, nitric oxide, hydroxyl and superoxide radical scavenging activities, carotene/linoleic acid bleaching activity were used for the determination of antioxidant capacity. Results The total phenolics in Boerhaavia diffusa (82.79-162.80 mg GAE/g extract) were found to be higher when compared to that of Portulaca oleracea (22.94-10.02 mg GAE/g extract). Hydrothermal processing enhanced the level of inhibition on synthetic radicals such as DPPH (3 439-309 549 mmol TE/g extract) and ABTS (17 808-53 818 mmol TE/g extract) as well as biologically relevant radicals such as superoxide anion (70%-90%) and nitric oxide (49%-57%). In addition, boiling of the vegetables were found to be maximum capacity of FRAP (6 404.95 mmol Fe (II)/g extract) and metal chelating activity (1.53 mg EDTA/g extract) than the respective raw samples. Conclusions The present investigation suggests that the processing enhance the functionality and improves the availability of bioactive substances of these vegetables. In addition, they also exhibited more potent antioxidant activity. Therefore these natural weeds from the crop land ecosystem could be suggested as cost effective indigenous green vegetables for human diet and potential feed resources for animals. Further extensive studies on role and importance of those weeds in sustaining the agro biodiversity are also needed. PMID:25183131

The interplay of intention, autonomy, and sex with dietary planning: A conditional process model to predict fruit and vegetable intake.

PubMed

Lange, Daniela; Corbett, Jana; Lippke, Sonia; Knoll, Nina; Schwarzer, Ralf

2015-11-01

Dietary intentions are supposed to engender planning processes, which in turn stimulate dietary behaviour change. However, some studies failed to find such mediation effects, which suggest more complex and not yet unravelled relationships between these factors. One explanation may be that mediation works better under certain circumstances or only for specific subgroups. This study addresses this reasoning by examining autonomy beliefs and sex as putative moderators of the hypothesized mediation chain. In a longitudinal design with three measurement points in time (1 week and 1 month apart), 912 women and 214 men were surveyed. Planning, intention, dietary autonomy beliefs, and sex were used to predict fruit and vegetable intake within a conditional process model designed to identify mechanisms of change. The intention-planning-behaviour chain was qualified by a triple interaction involving autonomy beliefs and sex as moderators between intention and planning. Higher dietary autonomy resulted in higher levels of planning fruit and vegetable intake. For men, even in case of higher intention, at least medium levels of autonomy beliefs were necessary to facilitate planning processes. For women, already lower levels of autonomy beliefs can engender postintentional planning strategies and seem to even compensate lower intention. Intention and planning are key predictors of dietary change. However, these variables work better under specific conditions (with a sufficient level of autonomy), and differently in subgroups (men vs. women). These results may explain the inconsistent findings of previous studies on the mediating effect of planning and allow for a better description of the mechanisms by which intentions may influence behaviour. Statement of contribution What is already known on this subject? The adoption of health-enhancing dietary behaviours can be facilitated by intentions and planning. Planning to eat more fruit and vegetable helps to translate intentions into

Review of vegetable fermentations with particular emphasis on processing modifications, microbial ecology, and spoilage

USDA-ARS?s Scientific Manuscript database

The consumption of vegetables is widespread in the world and represents a major component of the human diet. Microorganisms (mainly lactic acid bacteria, yeasts, Enterobacteriaceae, Propionibacterium and Clostridium species) play a significant role in vegetable fermentations, affecting the quality a...

Fluorescence lidar multi-color imaging of vegetation

NASA Technical Reports Server (NTRS)

Johansson, J.; Wallinder, E.; Edner, H.; Svanberg, S.

1992-01-01

Multi-color imaging of vegetation fluorescence following laser excitation is reported for distances of 50 m. A mobile laser radar system equipped with a Nd:YAG laser transmitter and a 40 cm diameter telescope was used. Image processing allows extraction of information related to the physiological status of the vegetation and might prove useful in forest decline research.

The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams

Treesearch

Michael G. Dosskey; Philippe Vidon; Noel P. Gurwick; Craig J. Allan; Tim P. Duval; Richard Lowrance

2010-01-01

We review the research literature and summarize the major processes by which riparian vegetation influences chemical water quality in streams, as well as how these processes vary among vegetation types, and discuss how these processes respond to removal and restoration of riparian vegetation and thereby determine the timing and level of response in stream water quality...

Incorporating geometrically complex vegetation in a computational fluid dynamic framework

NASA Astrophysics Data System (ADS)

Boothroyd, Richard; Hardy, Richard; Warburton, Jeff; Rosser, Nick

2015-04-01

Vegetation is known to have a significant influence on the hydraulic, geomorphological, and ecological functioning of river systems. Vegetation acts as a blockage to flow, thereby causing additional flow resistance and influencing flow dynamics, in particular flow conveyance. These processes need to be incorporated into flood models to improve predictions used in river management. However, the current practice in representing vegetation in hydraulic models is either through roughness parameterisation or process understanding derived experimentally from flow through highly simplified configurations of fixed, rigid cylinders. It is suggested that such simplifications inadequately describe the geometric complexity that characterises vegetation, and therefore the modelled flow dynamics may be oversimplified. This paper addresses this issue by using an approach combining field and numerical modelling techniques. Terrestrial Laser Scanning (TLS) with waveform processing has been applied to collect a sub-mm, 3-dimensional representation of Prunus laurocerasus, an invasive species to the UK that has been increasingly recorded in riparian zones. Multiple scan perspectives produce a highly detailed point cloud (>5,000,000 individual data points) which is reduced in post processing using an octree-based voxelisation technique. The method retains the geometric complexity of the vegetation by subdividing the point cloud into 0.01 m3 cubic voxels. The voxelised representation is subsequently read into a computational fluid dynamic (CFD) model using a Mass Flux Scaling Algorithm, allowing the vegetation to be directly represented in the modelling framework. Results demonstrate the development of a complex flow field around the vegetation. The downstream velocity profile is characterised by two distinct inflection points. A high velocity zone in the near-bed (plant-stem) region is apparent due to the lack of significant near-bed foliage. Above this, a zone of reduced velocity is

Osmotic dehydration of fruits and vegetables: a review.

PubMed

Yadav, Ashok Kumar; Singh, Satya Vir

2014-09-01

The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effects of osmotic dehydration have been reviewed. Studied showed that combination of different osmotic agents were more effective than sucrose alone due to combination of properties of solutes. During the experiments it was found that optimum osmosis was found at approximately 40 °C, 40 °B of osmotic agent and in near about 132 min. Pretreatments also leads to increase the osmotic process in fruits and vegetables. Mass transfer kinetics study is an important parameter to study osmosis. Solids diffusivity were found in wide range (5.09-32.77 kl/mol) studied by Fick's laws of diffusion. These values vary depending upon types of fruits and vegetables and osmotic agents.

Evaluating models of climate and forest vegetation

NASA Technical Reports Server (NTRS)

Clark, James S.

1992-01-01

Understanding how the biosphere may respond to increasing trace gas concentrations in the atmosphere requires models that contain vegetation responses to regional climate. Most of the processes ecologists study in forests, including trophic interactions, nutrient cycling, and disturbance regimes, and vital components of the world economy, such as forest products and agriculture, will be influenced in potentially unexpected ways by changing climate. These vegetation changes affect climate in the following ways: changing C, N, and S pools; trace gases; albedo; and water balance. The complexity of the indirect interactions among variables that depend on climate, together with the range of different space/time scales that best describe these processes, make the problems of modeling and prediction enormously difficult. These problems of predicting vegetation response to climate warming and potential ways of testing model predictions are the subjects of this chapter.

Processing Of Neem And Jatropha Methyl Esters -Alternative Fuels From Vegetable Oil

NASA Astrophysics Data System (ADS)

Ramasubramanian, S.; Manavalan, S.; Gnanavel, C.; Balakrishnan, G.

2017-03-01

Biodiesel is an alternative fuel for diesel engine. The methyl esters of vegetable oils, known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engine. This paper deals with the manufacturing process of Biodiesel from jatropha and neem oil. Biodiesel was prepared from neem oil and jatropha oil, the transestrified having kinematic viscosity of 3 & 2.6 centistokes, methanol ratio is 6:1 & 5.1respectively. The secondary solution is preheated at 65 C & 60 C and reaction temperature is maintained at 60C & 55 C and reaction time is 60 minutes approximately with NaOH catalyst and low viscosity oil is allowed to settle 24 hours. The average yield of neem and jatropha methyl esters was about 85%. These methyl esters shows excellent alternative under optimum condition for fossil fuels.

Suppression of vegetation in LANDSAT ETM+ remote sensing images

NASA Astrophysics Data System (ADS)

Yu, Le; Porwal, Alok; Holden, Eun-Jung; Dentith, Michael

2010-05-01

value and scaling all pixels at each vegetation index level by an amount that shifts the curve to the target digital number (DN). The main drawback of their algorithm is severe distortions of the DN values of non-vegetated areas, a suggested solution is masking outliers such as cloud, water, etc. We therefore extend this algorithm by masking non-vegetated areas. Our algorithm comprises the following three steps: (1) masking of barren or sparsely vegetated areas using a threshold based on a vegetation index that is calculated after atmosphere correction (dark pixel correction and ACTOR were compared) in order to conserve their original spectral information through the subsequent processing; (2) applying Crippen and Blom's forced invariance algorithm to suppress the spectral response of vegetation only in vegetated areas; and (3) combining the processed vegetated areas with the masked barren or sparsely vegetated areas followed by histogram equalization to eliminate the differences in color-scales between these two types of areas, and enhance the integrated image. The output images of both study areas showed significant improvement over the original images in terms of suppression of vegetation reflectance and enhancement of the underlying geological information. The processed images show clear banding, probably associated with lithological variations in the underlying rock formations. The colors of non-vegetated pixels are distorted in the unmasked results but in the same location the pixels in the masked results show regions of higher contrast. We conclude that the algorithm offers an effective way to enhance geological information in LANDSAT TM/ETM+ images of terrains with significant vegetation cover. It is also suitable to other multispectral satellite data have bands in similar wavelength regions. In addition, an application of this method to hyperspectral data may be possible as long as it can provide the vegetation band ratios.

Emotional Processing of Personally Familiar Faces in the Vegetative State

PubMed Central

Sharon, Haggai; Pasternak, Yotam; Ben Simon, Eti; Gruberger, Michal; Giladi, Nir; Krimchanski, Ben Zion; Hassin, David; Hendler, Talma

2013-01-01

Background The Vegetative State (VS) is a severe disorder of consciousness in which patients are awake but display no signs of awareness. Yet, recent functional magnetic resonance imaging (fMRI) studies have demonstrated evidence for covert awareness in VS patients by recording specific brain activations during a cognitive task. However, the possible existence of incommunicable subjective emotional experiences in VS patients remains largely unexplored. This study aimed to probe the question of whether VS patients retain a brain ability to selectively process external stimuli according to their emotional value and look for evidence of covert emotional awareness in patients. Methods and Findings In order to explore these questions we employed the emotive impact of observing personally familiar faces, known to provoke specific perceptual as well as emotional brain activations. Four VS patients and thirteen healthy controls first underwent an fMRI scan while viewing pictures of non-familiar faces, personally familiar faces and pictures of themselves. In a subsequent imagery task participants were asked to actively imagine one of their parent's faces. Analyses focused on face and familiarity selective regional brain activations and inter-regional functional connectivity. Similar to controls, all patients displayed face selective brain responses with further limbic and cortical activations elicited by familiar faces. In patients as well as controls, Connectivity was observed between emotional, visual and face specific areas, suggesting aware emotional perception. This connectivity was strongest in the two patients who later recovered. Notably, these two patients also displayed selective amygdala activation during familiar face imagery, with one further exhibiting face selective activations, indistinguishable from healthy controls. Conclusions Taken together, these results show that selective emotional processing can be elicited in VS patients both by external emotionally

Family Members' Influence on Family Meal Vegetable Choices

ERIC Educational Resources Information Center

Wenrich, Tionni R.; Brown, J. Lynne; Miller-Day, Michelle; Kelley, Kevin J.; Lengerich, Eugene J.

2010-01-01

Objective: Characterize the process of family vegetable selection (especially cruciferous, deep orange, and dark green leafy vegetables); demonstrate the usefulness of Exchange Theory (how family norms and experiences interact with rewards and costs) for interpreting the data. Design: Eight focus groups, 2 with each segment (men/women vegetable…

Survival and growth of foodborne pathogens in minimally processed vegetables at 4 and 15 °C.

PubMed

Tian, Jun-Qi; Bae, Young-Min; Choi, Na-Young; Kang, Dong-Hyun; Heu, Sunggi; Lee, Sun-Young

2012-01-01

We conducted this study to investigate the survival and growth of pathogens on fresh vegetables stored at 4 and 15 °C. Vegetables (romaine lettuce, iceberg lettuce, perilla leaves, and sprouts) were inoculated with 4 pathogens (Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157:H7) and stored at 2 different temperatures for different periods of time (3, 6, 9, 12, and 15 d at 4 °C and 1, 2, 3, 5, and 7 d at 15 °C). Populations of the 4 pathogens tended to increase on all vegetables stored at 15 °C for 7 d. Populations of E. coli O157:H7 and S. Typhimurium increased significantly, by approximately 2 log₁₀ CFU/g, on loose and head lettuce stored at 15 °C for 1 d. No significant differences were observed in the growth of different pathogens on vegetables stored at 4 °C for 15 d. E. coli O157:H7 did not survive on sprouts stored at 15 or 4 °C. The survival and growth of food pathogens on fresh vegetables were very different depending on the pathogen type and storage temperature. Survivals and growth of pathogens on various vegetables at 4 and 15 °C were observed in this study. Survivals and growth of pathogens on vegetables were different depending on the pathogen type and storage temperature. Therefore, vegetables should be stored under refrigerated conditions (below 4 °C) prior to consumption. This recommendation may vary depending on the type of vegetable. © 2011 Institute of Food Technologists®

Modeling Vegetation Growth Impact on Groundwater Recharge

NASA Astrophysics Data System (ADS)

Anurag, H.; Ng, G. H. C.; Tipping, R.

2017-12-01

Vegetation growth is affected by variability in climate and land-cover / land-use over a range of temporal and spatial scales. Vegetation also modifies water budget through interception and evapotranspiration and thus has a significant impact on groundwater recharge. Most groundwater recharge assessments represent vegetation using specified, static parameter, such as for leaf-area-index, but this neglects the effect of vegetation dynamics on recharge estimates. Our study addresses this gap by including vegetation growth in model simulations of recharge. We use NCAR's Community Land Model v4.5 with its BGC module (BGC is the new CLM4.5 biogeochemistry). It integrates prognostic vegetation growth with land-surface and subsurface hydrological processes and can thus capture the effect of vegetation on groundwater. A challenge, however, is the need to resolve uncertainties in model inputs ranging from vegetation growth parameters all the way down to the water table. We have compiled diverse data spanning meteorological inputs to subsurface geology and use these to implement ensemble model simulations to evaluate the possible effects of dynamic vegetation growth (versus specified, static vegetation parameterizations) on estimating groundwater recharge. We present preliminary results for select data-intensive test locations throughout the state of Minnesota (USA), which has a sharp east-west precipitation gradient that makes it an apt testbed for examining ecohydrologic relationships across different temperate climatic settings and ecosystems. Using the ensemble simulations, we examine the effect of seasonal to interannual variability of vegetation growth on recharge and water table depths, which has implications for predicting the combined impact of climate, vegetation, and geology on groundwater resources. Future work will include distributed model simulations over the entire state, as well as conditioning uncertain vegetation and subsurface parameters on remote sensing

Seasonally asymmetric enhancement of northern vegetation productivity

NASA Astrophysics Data System (ADS)

Park, T.; Myneni, R.

2017-12-01

Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

Behavior of glucosinolates in pickling cruciferous vegetables.

PubMed

Suzuki, Chise; Ohnishi-Kameyama, Mayumi; Sasaki, Keisuke; Murata, Takashi; Yoshida, Mitsuru

2006-12-13

Crucifer species, which include widely consumed vegetables, contain glucosinolates as secondary metabolites. Cruciferous vegetables are consumed in Japan in salt-preserved or pickled form as well as cooked and raw fresh vegetables. In this study, changes in contents of glucosinolates during the pickling process were investigated. 4-Methylthio-3-butenyl glucosinolate, a major glucosinolate in the root of Japanese radish, daikon (Raphanus sativus L.), was detected in pickled products with a short maturation period but not in those with a long maturation period. As a model pickling experiment, fresh watercress (Nasturtium officinale) and blanched watercress were soaked in 3% NaCl solution for 7 days. The results showed that the ratio of indole glucosinolates to total glucosinolates increased during the pickling process, whereas total glucosinolates decreased. Myrosinase digestion of glucosinolates in nozawana (Brassica rapa L.) indicated that indole glucosinolates, especially 4-methoxyglucobrassicin, were relatively resistant to the enzyme. The effect of pickling on glucosinolate content and the possible mechanism are discussed in view of degradation by myrosinase and synthetic reaction in response to salt stress or compression during the pickling process.

The effects of vegetation and climate change on catchment erosion over millennial time scales: Insights from coupled dynamic vegetation and landscape evolution models

NASA Astrophysics Data System (ADS)

Schmid, Manuel; Ehlers, Todd; Werner, Christian; Hickler, Thomas

2017-04-01

Recent studies hypothesize that vegetation and the morphology of landscapes are strongly coupled. On a small scale, plants influence the erosivity of soil and sediments and therefore systematically impact catchment erosion and topography. Previous landscape evolution modeling studies primarily focus on changes in fluvial and hillslope erosion due to variations in climate and tectonics, without explicit consideration of vegetation effects. In this study, we complement previous work by investigating the effects of vegetation and vegetation change on hillslope and fluvial processes by combining LPJ-GUESS, a dynamic global vegetation model, with a modified version of the Landlab surface process model. The LandLab model was extended to account for vegetation-dependent sediment fluxes for both hillslope and detachment-limited fluvial erosion. The models are coupled by using predicted changes in surface vegetation from LPJ-GUESS for different climate scenarios as input for vegetation dependent erosional coefficients in Landlab. Simulations were conducted with the general climate and vegetation conditions representative between 25° and 40°S along the Coastal Cordillera of Chile. This region is the focus of the EarthShape research program (www.earthshape.net). These areas present a natural climatic and associated vegetation gradient that ranges from hyper-arid (Atacama desert) to humid-temperate conditions without a dry season and pristine temperate Araucaria forest. All study areas considered have a similar and uniform granite substrate, which minimizes lithologic variations and their effect on catchment erosion. Simulations are in progress that were designed to independently determine the climatic or vegetation controls on topography and erosion histories over the last 21 kyr. Our preliminary findings suggest that an increase in the surface vegetation results in a modulation of the mean hillslope angle and the average drainage density. In addition, we find that a

Assessing global vegetation activity using spatio-temporal Bayesian modelling

NASA Astrophysics Data System (ADS)

Mulder, Vera L.; van Eck, Christel M.; Friedlingstein, Pierre; Regnier, Pierre A. G.

2016-04-01

This work demonstrates the potential of modelling vegetation activity using a hierarchical Bayesian spatio-temporal model. This approach allows modelling changes in vegetation and climate simultaneous in space and time. Changes of vegetation activity such as phenology are modelled as a dynamic process depending on climate variability in both space and time. Additionally, differences in observed vegetation status can be contributed to other abiotic ecosystem properties, e.g. soil and terrain properties. Although these properties do not change in time, they do change in space and may provide valuable information in addition to the climate dynamics. The spatio-temporal Bayesian models were calibrated at a regional scale because the local trends in space and time can be better captured by the model. The regional subsets were defined according to the SREX segmentation, as defined by the IPCC. Each region is considered being relatively homogeneous in terms of large-scale climate and biomes, still capturing small-scale (grid-cell level) variability. Modelling within these regions is hence expected to be less uncertain due to the absence of these large-scale patterns, compared to a global approach. This overall modelling approach allows the comparison of model behavior for the different regions and may provide insights on the main dynamic processes driving the interaction between vegetation and climate within different regions. The data employed in this study encompasses the global datasets for soil properties (SoilGrids), terrain properties (Global Relief Model based on SRTM DEM and ETOPO), monthly time series of satellite-derived vegetation indices (GIMMS NDVI3g) and climate variables (Princeton Meteorological Forcing Dataset). The findings proved the potential of a spatio-temporal Bayesian modelling approach for assessing vegetation dynamics, at a regional scale. The observed interrelationships of the employed data and the different spatial and temporal trends support

Illuminating hydrological processes at the soil-vegetation-atmosphere interface with water stable isotopes

NASA Astrophysics Data System (ADS)

Sprenger, Matthias; Leistert, Hannes; Gimbel, Katharina; Weiler, Markus

2016-09-01

Water stable isotopes (18O and 2H) are widely used as ideal tracers to track water through the soil and to separate evaporation from transpiration. Due to the technical developments in the last two decades, soil water stable isotope data have become easier to collect. Thus, the application of isotope methods in soils is growing rapidly. Studies that make use of soil water stable isotopes often have a multidisciplinary character since an interplay of processes that take place in the vadose zone has to be considered. In this review, we provide an overview of the hydrological processes that alter the soil water stable isotopic composition and present studies utilizing pore water stable isotopes. The processes that are discussed include the water input as precipitation or throughfall, the output as evaporation, transpiration, or recharge, and specific flow and transport processes. Based on the review and supported by additional data and modeling results, we pose a different view on the recently proposed two water world hypothesis. As an alternative to two distinct pools of soil water, where one pool is enriched in heavy isotopes and used by the vegetation and the other pool does not undergo isotopic fractionation and becomes recharge, the water gets successively mixed with newly introduced rainwater during the percolation process. This way, water initially isotopically enriched in the topsoil loses the fractionation signal with increasing infiltration depth, leading to unfractionated isotopic signals in the groundwater.

Inventories of Delaware's coastal vegetation and land-use utilizing digital processing of ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Bartlett, D.; Rogers, R.; Reed, L.

1974-01-01

The author has identified the following significant results. Analysis of ERTS-1 color composite images using analogy processing equipment confirmed that all the major wetlands plant species were distinguishable at ERTS-1 scale. Furthermore, human alterations of the coastal zone were easily recognized since such alterations typically involve removal of vegetative cover resulting in a change of spectral signature. The superior spectral resolution of the CCTs as compared with single band or composite imagery has indeed provided good discrimination through digital analysis of the CCTs with the added advantage of rapid production of thematic maps and data.

Modeling vegetation rooting strategies on a hillslope

NASA Astrophysics Data System (ADS)

Sivandran, G.; Bras, R. L.

2011-12-01

The manner in which water and energy is partitioned and redistributed along a hillslope is the result of complex coupled ecohydrological interactions between the climatic, soils, topography and vegetation operating over a wide range of spatiotemporal scales. Distributed process based modeling creates a framework through which the interaction of vegetation with the subtle differences in the spatial and temporal dynamics of soil moisture that arise under localized abiotic conditions along a hillslope can be simulated and examined. One deficiency in the current dynamic vegetation models is the one sided manner in which vegetation responds to soil moisture dynamics. Above ground, vegetation is given the freedom to dynamically evolve through alterations in fractional vegetation cover and/or canopy height and density; however below ground rooting profiles are simplistically represented and often held constant in time and space. The need to better represent the belowground role of vegetation through dynamic rooting strategies is fundamental in capturing the magnitude and timing of water and energy fluxes between the atmosphere and land surface. In order to allow vegetation to adapt to gradients in soil moisture a dynamic rooting scheme was incorporated into tRIBS+VEGGIE (a physically based distributed ecohydrological model). The dynamic rooting scheme allows vegetation the freedom to adapt their rooting depth and distribution in response abiotic conditions in a way that more closely mimics observed plant behavior. The incorporation of this belowground plasticity results in vegetation employing a suite of rooting strategies based on soil texture, climatic conditions and location on the hillslope.

Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves.

PubMed

Figiel, Adam; Michalska, Anna

2016-12-30

The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.

Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves

PubMed Central

Figiel, Adam; Michalska, Anna

2016-01-01

The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying. PMID:28042845

Importance of vegetation dynamics for future terrestrial carbon cycling

NASA Astrophysics Data System (ADS)

Ahlström, Anders; Xia, Jianyang; Arneth, Almut; Luo, Yiqi; Smith, Benjamin

2015-05-01

Terrestrial ecosystems currently sequester about one third of anthropogenic CO2 emissions each year, an important ecosystem service that dampens climate change. The future fate of this net uptake of CO2 by land based ecosystems is highly uncertain. Most ecosystem models used to predict the future terrestrial carbon cycle share a common architecture, whereby carbon that enters the system as net primary production (NPP) is distributed to plant compartments, transferred to litter and soil through vegetation turnover and then re-emitted to the atmosphere in conjunction with soil decomposition. However, while all models represent the processes of NPP and soil decomposition, they vary greatly in their representations of vegetation turnover and the associated processes governing mortality, disturbance and biome shifts. Here we used a detailed second generation dynamic global vegetation model with advanced representation of vegetation growth and mortality, and the associated turnover. We apply an emulator that describes the carbon flows and pools exactly as in simulations with the full model. The emulator simulates ecosystem dynamics in response to 13 different climate or Earth system model simulations from the Coupled Model Intercomparison Project Phase 5 ensemble under RCP8.5 radiative forcing. By exchanging carbon cycle processes between these 13 simulations we quantified the relative roles of three main driving processes of the carbon cycle; (I) NPP, (II) vegetation dynamics and turnover and (III) soil decomposition, in terms of their contribution to future carbon (C) uptake uncertainties among the ensemble of climate change scenarios. We found that NPP, vegetation turnover (including structural shifts, wild fires and mortality) and soil decomposition rates explained 49%, 17% and 33%, respectively, of uncertainties in modelled global C-uptake. Uncertainty due to vegetation turnover was further partitioned into stand-clearing disturbances (16%), wild fires (0%), stand

Handling Procedures of Vegetable Crops

NASA Technical Reports Server (NTRS)

Perchonok, Michele; French, Stephen J.

2004-01-01

The National Aeronautics and Space Administration (NASA) is working towards future long duration manned space flights beyond low earth orbit. The duration of these missions may be as long as 2.5 years and will likely include a stay on a lunar or planetary surface. The primary goal of the Advanced Food System in these long duration exploratory missions is to provide the crew with a palatable, nutritious, and safe food system while minimizing volume, mass, and waste. Vegetable crops can provide the crew with added nutrition and variety. These crops do not require any cooking or food processing prior to consumption. The vegetable crops, unlike prepackaged foods, will provide bright colors, textures (crispy), and fresh aromas. Ten vegetable crops have been identified for possible use in long duration missions. They are lettuce, spinach, carrot, tomato, green onion, radish, bell pepper, strawberries, fresh herbs, and cabbage. Whether these crops are grown on a transit vehicle (e.g., International Space Station) or on the lunar or planetary surface, it will be necessary to determine how to safely handle the vegetables while maintaining acceptability. Since hydrogen peroxide degrades into water and oxygen and is generally recognized as safe (GRAS), hydrogen peroxide has been recommended as the sanitizer. The objective of th is research is to determine the required effective concentration of hydrogen peroxide. In addition, it will be determined whether the use of hydrogen peroxide, although a viable sanitizer, adversely affects the quality of the vegetables. Vegetables will be dipped in 1 % hydrogen peroxide, 3% hydrogen peroxide, or 5% hydrogen peroxide. Treated produce and controls will be stored in plastic bags at 5 C for up to 14 days. Sensory, color, texture, and total plate count will be measured. The effect on several vegetables including lettuce, radish, tomato and strawberries has been completed. Although each vegetable reacts to hydrogen peroxide differently, the

Unlikely Nomads: Settlement, Establishment, and Dislodgement Processes of Vegetative Seagrass Fragments

PubMed Central

Lai, Samantha; Yaakub, Siti Maryam; Poh, Tricia S. M.; Bouma, Tjeerd J.; Todd, Peter A.

2018-01-01

The dispersal of seagrasses is important to promoting the resilience and long-term survival of populations. Most of the research on long-distance dispersal to date has focused on sexual propagules while the dispersal of vegetative fragments has been largely overlooked, despite the important role this mechanism might play. In this study, we proposed a conceptual model that categorizes vegetative fragment dispersal into seven fundamental steps: i.e., (i) fragment formation, (ii) transport, (iii) decay, (iv) substrate contact, (v) settlement, (vi) establishment, and (vii) dislodgement. We present two experiments focusing on the final steps of the model from substrate contact to dislodgement in four tropical seagrass species (Cymodocea rotundata, Halophila ovalis, Halodule uninervis, and Thalassia hemprichii), which are critical for dispersed vegetative fragments to colonize new areas. We first conducted a mesocosm experiment to investigate the effect of fragment age and species on settlement (i.e., remains on the substrate in a rising tide) and subsequently establishment (i.e., rooting in substrate) rates. To determine dislodgement resistance of settled fragments, we also subjected fragments under different burial treatments to wave and currents in a flume. We found that both initial settlement and subsequent establishment rates increased with fragment age. H. ovalis was the only species that successfully established within the study period. After settlement, dislodgement resistance depended primarily on burial conditions. Smaller species H. ovalis and H. uninervis were also able to settle more successfully, and withstand higher bed shear stress before being dislodged, compared to the larger species T. hemprichii and C. rotundata. However, the ordinal logistic regressions did not reveal relationships between the tested plant morphometrics and the energy needed for dislodgement (with the exception of C. rotundata), indicating that there are potentially some untested

Agricultural recycling of treatment-plant sludge: a case study for a vegetable-processing factory.

PubMed

Dolgen, Deniz; Alpaslan, M Necdet; Delen, Nafiz

2007-08-01

The present study evaluated the possibility of using the sludge produced by a vegetable-processing factory in agriculture. The sludge was amended with a soil mixture (i.e., a mixture of sand, soil, and manure) and was applied at 0, 165, 330, 495 and 660 t/ha to promote the growth of cucumbers. The effects of various sludge loadings on plant growth were assessed by counting plants and leaves, measuring stem lengths, and weighing the green parts and roots of the plants. We also compared heavy metal uptake by the plants for sludge loadings of 330, 495, and 660 t/ha with various recommended standards for vegetables. Our results showed that plant growth patterns were influenced to some extent by the sludge loadings. In general, the number of leaves, stem length, and dry weight of green parts exhibited a pronounced positive growth response compared with an unfertilized control, and root growth showed a lesser but still significant response at sludge loadings of 165 and 330 t/ha. The sludge application caused no significant increase in heavy metal concentrations in the leaves, though zinc (Zn) and iron (Fe) were found at elevated concentrations. However, despite the Zn and Fe accumulation, we observed no toxicity symptoms in the plants. This may be a result of cucumber's tolerance of high metal levels.

Vegetable variety: an effective strategy to increase vegetable intake in adults

PubMed Central

Meengs, Jennifer S.; Roe, Liane S.; Rolls, Barbara J.

2012-01-01

Effective strategies are needed to increase vegetable intake in accordance with health recommendations. Previous research has shown that increasing the variety of foods leads to increased consumption, yet this strategy has not been investigated for promoting vegetable intake. This cross-over study tested whether filling half the plate with a variety of vegetables influences vegetable consumption and meal energy intake. Once a week for 4 weeks, a meal of pasta and cooked vegetables was consumed ad libitum by 66 adults (34 women; 32 men). The meals were varied in the type of vegetables offered; at three meals 600 g of a single vegetable was served (broccoli, carrots, or snap peas) and at one meal 200 g of each of the three vegetables was served side by side. The experiment was conducted in 2008 and 2009 and data were analyzed using a mixed linear model with repeated measures. The results showed that serving a variety of vegetables increased vegetable intake at the meal (P<0.0001). Subjects ate more vegetables when served the variety than when served any single type; the mean increase was 48±6 g, or more than one-half serving. This increase remained significant when intake of the variety of vegetables was compared to the preferred vegetable of each participant (mean 25±8 g; P=0.002). Vegetable intake was not significantly related to energy intake at the meal. The results of this study demonstrate that increasing the variety of low-energy-dense vegetables served at a meal can be used as a strategy to increase vegetable intake. PMID:22818729

Vegetable variety: an effective strategy to increase vegetable intake in adults.

PubMed

Meengs, Jennifer S; Roe, Liane S; Rolls, Barbara J

2012-08-01

Effective strategies are needed to increase vegetable intake in accordance with health recommendations. Previous research has shown that increasing the variety of foods leads to increased consumption, yet this strategy has not been investigated for promoting vegetable intake. This crossover study, conducted in 2008 and 2009, tested whether filling half the plate with a variety of vegetables influences vegetable consumption and meal energy intake. Once a week for 4 weeks, a meal of pasta and cooked vegetables was consumed ad libitum by 66 adults (34 women, 32 men). The meals were varied in the type of vegetables offered: at three meals 600 g of a single vegetable was served (broccoli, carrots, or snap peas) and at one meal 200 g of each of the three vegetables was served side by side. Data were analyzed using a mixed linear model with repeated measures. In this study, serving a variety of vegetables increased vegetable intake at the meal (P<0.0001). Subjects ate more vegetables when served the variety than when served any single type; the mean increase was 48±6 g, or more than one-half serving. This increase remained significant when intake of the variety of vegetables was compared with the preferred vegetable of each participant (mean 25±8 g; P=0.002). Vegetable intake was not significantly related to energy intake at the meal. The results of this study demonstrate that increasing the variety of low-energy-dense vegetables served at a meal can be used as a strategy to increase vegetable intake. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

NASA Astrophysics Data System (ADS)

Ma, Z.; Zhou, G.

2018-04-01

The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

Interactions among hydrogeomorphology, vegetation, and nutrient biogeochemistry in floodplain ecosystems

USGS Publications Warehouse

Noe, G.B.; Shroder, John F.

2013-01-01

Hydrogeomorphic, vegetative, and biogeochemical processes interact in floodplains resulting in great complexity that provides opportunities to better understand linkages among physical and biological processes in ecosystems. Floodplains and their associated river systems are structured by four-dimensional gradients of hydrogeomorphology: longitudinal, lateral, vertical, and temporal components. These four dimensions create dynamic hydrologic and geomorphologic mosaics that have a large imprint on the vegetation and nutrient biogeochemistry of floodplains. Plant physiology, population dynamics, community structure, and productivity are all very responsive to floodplain hydrogeomorphology. The strength of this relationship between vegetation and hydrogeomorphology is evident in the use of vegetation as an indicator of hydrogeomorphic processes. However, vegetation also influences hydrogeomorphology by modifying hydraulics and sediment entrainment and deposition that typically stabilize geomorphic patterns. Nitrogen and phosphorus biogeochemistry commonly influence plant productivity and community composition, although productivity is not limited by nutrient availability in all floodplains. Conversely, vegetation influences nutrient biogeochemistry through direct uptake and storage as well as production of organic matter that regulates microbial biogeochemical processes. The biogeochemistries of nitrogen and phosphorus cycling are very sensitive to spatial and temporal variation in hydrogeomorphology, in particular floodplain wetness and sedimentation. The least-studied interaction is the direct effect of biogeochemistry on hydrogeomorphology, but the control of nutrient availability over organic matter decomposition and thus soil permeability and elevation is likely important. Biogeochemistry also has the more documented but indirect control of hydrogeomorphology through regulation of plant biomass. In summary, the defining characteristics of floodplain ecosystems

Interactions among hydrogeomorphology, vegetation, and nutrient biogeochemistry in floodplain ecosystems

USGS Publications Warehouse

Noe, G.B.

2013-01-01

Hydrogeomorphic, vegetative, and biogeochemical processes interact in floodplains resulting in great complexity that provides opportunities to better understand linkages among physical and biological processes in ecosystems. Floodplains and their associated river systems are structured by four dimensional gradients of hydrogeomorphology: longitudinal, lateral, vertical, and temporal components. These four dimensions create dynamic hydrologic and geomorphologic mosaics that have a large imprint on the vegetation and nutrient biogeochemistry of floodplains. Plant physiology, population dynamics, community structure, and productivity are all very responsive to floodplain hydrogeomorphology. The strength of this relationship between vegetation and hydrogeomorphology is evident in the use of vegetation as an indicator of hydrogeomorphic processes. However, vegetation also influences hydrogeomorphology by modifying hydraulics and sediment entrainment and deposition that typically stabilize geomorphic patterns. Nitrogen and phosphorus biogeochemistry commonly influence plant productivity and community composition, although productivity is not limited by nutrient availability in all floodplains. Conversely, vegetation influences nutrient biogeochemistry through direct uptake and storage as well as production of organic matter that regulates microbial biogeochemical processes. The biogeochemistries of nitrogen and phosphorus cycling are very sensitive to spatial and temporal variation in hydrogeomorphology, in particular floodplain wetness and sedimentation. The least studied interaction is the direct effect of biogeochemistry on hydrogeomorphology, but the control of nutrient availability over organic matter decomposition and thus soil permeability and elevation is likely important. Biogeochemistry also has the more documented but indirect control of hydrogeomorphology through regulation of plant biomass. In summary, the defining characteristics of floodplain ecosystems

Optimization of cow dung spiked pre-consumer processing vegetable waste for vermicomposting using Eisenia fetida.

PubMed

Garg, V K; Gupta, Renuka

2011-01-01

This paper reports the optimization of cow dung (CD) spiked pre-consumer processing vegetable waste (PPVW) for vermicomposting using Eisenia fetida in a laboratory scale study. Vermicomposting process decreased carbon and organic matter concentration and increased N, P and K content in the vermicompost. The C:N ratio was decreased by 45-69% in different vermireactors indicating stabilization of the waste. The heavy metal content was within permissible limits of their application in agricultural soils. It has been concluded from the results that addition of PPVW up to 40% with CD can produce a good quality vermicompost. Whereas, growth and fecundity of E. fetida was best when reared in 20% PPVW+80% CD feed mixture. However, higher percentages of PPVW in different vermireactors significantly affected the growth and fecundity of worms. Copyright © 2010 Elsevier Inc. All rights reserved.

[Nitrate accumulation in vegetables and its residual in vegetable fields].

PubMed

Wang, Zhaohui; Zong, Zhiqiang; Li, Shengxiu; Chen, Baoming

2002-05-01

Determinations of 11 kinds, 48 varieties of vegetables were carried out at different seasons. The results showed that nitrate-N concentrations in 20 vegetables reached Pollution Level 4 (NO3(-)-N > 325 mg.kg-1), which accounted for 41.7% of the total number of the sampled vegetables and included all of the leafy, and most of the melon, root, onion and garlic vegetables. Among them, 5 leafy vegetables even exceeded Level 4 (NO3(-)-N > 700 mg.kg-1). Although leafy vegetables were usually apt to heavily accumulate nitrate, most of them were with nitrate-N concentrations lower than Level 3 (NO3(-)-N < 325 mg.kg-1) in leave blades. Further investigation showed that vegetable soils accumulated more nitrates in each layer from 0 cm to 200 cm than did cereal crop soil. The total amount of residual nitrate-N was 1358.8 kg.hm-2 in the 200 cm soil profile of usual vegetable fields, and 1411.8 kg.hm-2 and 1520.9 kg.hm-2 in the 2-yaers and the 5-years long plastic greenhouse fields respectively, however that in the cereal crop fields was only 245.4 kg.hm-2. Nitrate residual in vegetable soils formed serious threats to underground water in vegetable growing areas.

Effects of climate change on forest vegetation [Chapter 6

Treesearch

Patrick N. Behrens; Robert E. Keane; David L. Peterson; Joanne J. Ho

2018-01-01

Projected rapid changes in climate will affect vegetation assemblages in the Intermountain Adaptation Partnership (IAP) region directly and indirectly. Direct effects include altered vegetation growth, mortality, and regeneration, and indirect effects include changes in disturbance regimes (Chapter 8) and interactions with altered ecosystem processes (e.g., hydrology,...

Study on leaching of pollutants from vegetable tanning residue.

PubMed

Mazumder, Debabrata; Biswas, Santosh; Bandyopadhyay, Pratip

2006-07-01

The processing of heavy leather employs the vegetable tanning method involving use of tan liquor. The solid residue of this vegetable tanning process aggravates the water pollution by means of leaching of tannin and other associatedpollutants. Tannin is a biologically resistant compound causing several problems in animal body. The present study dealt with the pollution hazard arising out of leaching of pollutants from the open dumped vegetable tanning residue by rainfall washing. The concerned pollutants were pH, Chemical Oxygen Demand (COD), tannin,sulfate and chloride concentration. To explore the possible extent of contamination of these pollutants in the leached water, two different masses (2 kg and 3 kg) of tanning residue were employed. The results of the study showed that there was a continuous release of pollutants from the vegetable tanning residue. Moreover, there was no regular variation in various pollutant concentrations in both the cases solely due to non-homogeneity of the residue.

Vegetation spatial variability and its effect on vegetation indices

NASA Technical Reports Server (NTRS)

Ormsby, J. P.; Choudhury, B. J.; Owe, M.

1987-01-01

Landsat MSS data were used to simulate low resolution satellite data, such as NOAA AVHRR, to quantify the fractional vegetation cover within a pixel and relate the fractional cover to the normalized difference vegetation index (NDVI) and the simple ratio (SR). The MSS data were converted to radiances from which the NDVI and SR values for the simulated pixels were determined. Each simulated pixel was divided into clusters using an unsupervised classification program. Spatial and spectral analysis provided a means of combining clusters representing similar surface characteristics into vegetated and non-vegetated areas. Analysis showed an average error of 12.7 per cent in determining these areas. NDVI values less than 0.3 represented fractional vegetated areas of 5 per cent or less, while a value of 0.7 or higher represented fractional vegetated areas greater than 80 per cent. Regression analysis showed a strong linear relation between fractional vegetation area and the NDVI and SR values; correlation values were 0.89 and 0.95 respectively. The range of NDVI values calculated from the MSS data agrees well with field studies.

Near ground level sensing for spatial analysis of vegetation

NASA Technical Reports Server (NTRS)

Sauer, Tom; Rasure, John; Gage, Charlie

1991-01-01

Measured changes in vegetation indicate the dynamics of ecological processes and can identify the impacts from disturbances. Traditional methods of vegetation analysis tend to be slow because they are labor intensive; as a result, these methods are often confined to small local area measurements. Scientists need new algorithms and instruments that will allow them to efficiently study environmental dynamics across a range of different spatial scales. A new methodology that addresses this problem is presented. This methodology includes the acquisition, processing, and presentation of near ground level image data and its corresponding spatial characteristics. The systematic approach taken encompasses a feature extraction process, a supervised and unsupervised classification process, and a region labeling process yielding spatial information.

Effects of Telecoupling on Global Vegetation Dynamics

NASA Astrophysics Data System (ADS)

Viña, A.; Liu, J.

2016-12-01

With the ever increasing trend in telecoupling processes, such as international trade, all countries around the world are becoming more interdependent. However, the effects of this growing interdependence on vegetation (e.g., shifts in the geographic extent and distribution) remain unknown even though vegetation dynamics are crucially important for food production, carbon sequestration, provision of other ecosystem services, and biodiversity conservation. In this study we evaluate the effects of international trade on the spatio-temporal trajectories of vegetation at national and global scales, using vegetation index imagery collected over more than three decades by the Advanced Very High Resolution Radiometer (AVHRR) satellite sensor series together with concurrent national and international data on international trade (and its associated movement of people, goods, services and information). The spatio-temporal trajectories of vegetation are obtained using the scale of fluctuation technique, which is based on the decomposition of the AVHRR image time series to obtain information on its spatial dependence structure over time. Similar to the correlation length, the scale of fluctuation corresponds to the range over which fluctuations in the vegetation index are spatially correlated. Results indicate that global vegetation has changed drastically over the last three decades. These changes are not uniform across space, with hotspots in active trading countries. This study not only has direct implications for understanding global vegetation dynamics, but also sheds important insights on the complexity of human-nature interactions across telecoupled systems.

The vegetative communities associated with mammals of the South. Chapter 2

Treesearch

Beverly Collins; Philip E. Hyatt; Margaret K. Trani

2007-01-01

This chapter describes the ecoregions and vegetation types associated with mammals of the South. The distribution of mammals in the South reflects historic biogeographical processes as well as physiography and vegetation.

Micro-topographic hydrologic variability due to vegetation acclimation under climate change

NASA Astrophysics Data System (ADS)

Le, P. V.; Kumar, P.

2012-12-01

Land surface micro-topography and vegetation cover have fundamental effects on the land-atmosphere interactions. The altered temperature and precipitation variability associated with climate change will affect the water and energy processes both directly and that mediated through vegetation. Since climate change induces vegetation acclimation that leads to shifts in evapotranspiration and heat fluxes, it further modifies microclimate and near-surface hydrological processes. In this study, we investigate the impacts of vegetation acclimation to climate change on micro-topographic hydrologic variability. The ability to accurately predict these impacts requires the simultaneous considerations of biochemical, ecophysiological and hydrological processes. A multilayer canopy-root-soil system model coupled with a conjunctive surface-subsurface flow model is used to capture the acclimatory responses and analyze the changes in dynamics of structure and connectivity of micro-topographic storage and in magnitudes of runoff. The study is performed using Light Detection and Ranging (LiDAR) topographic data in the Birds Point-New Madrid floodway in Missouri, U.S.A. The result indicates that both climate change and its associated vegetation acclimation play critical roles in altering the micro-topographic hydrological responses.

Serving vegetables first: A strategy to increase vegetable consumption in elementary school cafeterias.

PubMed

Elsbernd, S L; Reicks, M M; Mann, T L; Redden, J P; Mykerezi, E; Vickers, Z M

2016-01-01

Vegetable consumption in the United States is low despite the wealth of evidence that vegetables play an important role in reducing risk of various chronic diseases. Because eating patterns developed in childhood continue through adulthood, we need to form healthy eating habits in children. The objective of this study was to determine if offering vegetables before other meal components would increase the overall consumption of vegetables at school lunch. We served kindergarten through fifth-grade students a small portion (26-33 g) of a raw vegetable (red and yellow bell peppers) while they waited in line to receive the rest of their lunch meal. They then had the options to take more of the bell peppers, a different vegetable, or no vegetable from the lunch line. We measured the amount of each vegetable consumed by each child. Serving vegetables first greatly increased the number of students eating vegetables. On intervention days most of the vegetables consumed came from the vegetables-first portions. Total vegetable intake per student eating lunch was low because most students chose to not eat vegetables, but the intervention significantly increased this value. Serving vegetables first is a viable strategy to increase vegetable consumption in elementary schools. Long-term implementation of this strategy may have an important impact on healthy eating habits, vegetable consumption, and the health consequences of vegetable intake. Copyright © 2015 Elsevier Ltd. All rights reserved.

What Works? Process Evaluation of a School-Based Fruit and Vegetable Distribution Program in Mississippi

ERIC Educational Resources Information Center

Potter, Susan C.; Schneider, Doris; Coyle, Karin K.; May, Gary; Robin, Leah; Seymour, Jenna

2011-01-01

Background: During the 2004-2005 school year, the Mississippi Department of Education, Office of Child Nutrition, initiated a pilot program to distribute free fruit and vegetable snacks to students during the school day. This article describes the first-year implementation of the Mississippi Fruit and Vegetable Pilot Program. Methods: The process…

Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

USGS Publications Warehouse

Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S.L.; Poulter, B.; Viovy, N.

2013-01-01

Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and current regional forest carbon balance. The present study adapted the global process-based vegetation model ORCHIDEE to simulate the CO2 emissions from boreal forest fire and the subsequent recovery after a stand-replacing fire; the model represents postfire new cohort establishment, forest stand structure and the self-thinning process. Simulation results are evaluated against observations of three clusters of postfire forest chronosequences in Canada and Alaska. The variables evaluated include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index, and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). When forced by local climate and the atmospheric CO2 history at each chronosequence site, the model simulations generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with the measurement accuracy (for CO2 flux ~100 g C m−2 yr−1, for biomass carbon ~1000 g C m−2 and for soil carbon ~2000 g C m−2). We find that the current postfire forest carbon sink at the evaluation sites, as observed by chronosequence methods, is mainly due to a combination of historical CO2 increase and forest succession. Climate change and variability during this period offsets some of these expected carbon gains. The negative impacts of climate were a likely consequence of increasing water stress caused by significant temperature increases that were not matched by concurrent increases in precipitation. Our simulation

Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

NASA Astrophysics Data System (ADS)

Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S. L.; Poulter, B.; Viovy, N.

2013-12-01

Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and current regional forest carbon balance. The present study adapted the global process-based vegetation model ORCHIDEE to simulate the CO2 emissions from boreal forest fire and the subsequent recovery after a stand-replacing fire; the model represents postfire new cohort establishment, forest stand structure and the self-thinning process. Simulation results are evaluated against observations of three clusters of postfire forest chronosequences in Canada and Alaska. The variables evaluated include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index, and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). When forced by local climate and the atmospheric CO2 history at each chronosequence site, the model simulations generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with the measurement accuracy (for CO2 flux ~100 g C m-2 yr-1, for biomass carbon ~1000 g C m-2 and for soil carbon ~2000 g C m-2). We find that the current postfire forest carbon sink at the evaluation sites, as observed by chronosequence methods, is mainly due to a combination of historical CO2 increase and forest succession. Climate change and variability during this period offsets some of these expected carbon gains. The negative impacts of climate were a likely consequence of increasing water stress caused by significant temperature increases that were not matched by concurrent increases in precipitation. Our simulation results

Salt marsh vegetation promotes efficient tidal channel networks

PubMed Central

Kearney, William S.; Fagherazzi, Sergio

2016-01-01

Tidal channel networks mediate the exchange of water, nutrients and sediment between an estuary and marshes. Biology feeds back into channel morphodynamics through the influence of vegetation on both flow and the cohesive strength of channel banks. Determining how vegetation affects channel networks is essential in understanding the biological functioning of intertidal ecosystems and their ecosystem services. However, the processes that control the formation of an efficient tidal channel network remain unclear. Here we compare the channel networks of vegetated salt marshes in Massachusetts and the Venice Lagoon to unvegetated systems in the arid environments of the Gulf of California and Yemen. We find that the unvegetated systems are dissected by less efficient channel networks than the vegetated salt marshes. These differences in network geometry reflect differences in the branching and meandering of the channels in the network, characteristics that are related to the density of vegetation on the marsh. PMID:27430165

Simulating vegetation dynamics in Chile from 21ka BP to present: Effects of climate change on vegetation functions and cover

NASA Astrophysics Data System (ADS)

Werner, Christian; Liakka, Johan; Schmid, Manuel; Fuentes, Juan-Pablo; Ehlers, Todd A.; Hickler, Thomas

2017-04-01

Vegetation composition and establishment is strongly dependent on climate conditions but also a result of vegetation dynamics (competition for light, water and nutrients). In addition, vegetation exerts control over the development of landscapes as it mediates the climatic and hydrological forces shaping the terrain via hillslope and fluvial processes. At the same time, topography as well as soil texture and soil depth affect the microclimate, soil water storage and rooting space that is defining the environmental envelope for vegetation development. Within the EarthShape research program (www.earthshape.net) we evaluate these interactions by simulating the co-evolution of landscape and vegetation with a dynamic vegetation model (LPJ-GUESS) and a landscape evolution model (LandLab). LPJ-GUESS is a mechanistic model driven by daily or monthly weather data and explicitly simulates vegetation physiology, succession, competition and water and nutrient cycling. Here we present the results of first transient vegetation simulations from 21kyr BP to present-day using the TraCE-21ka climate dataset for four focus sites along the coastal cordillera of Chile that are exposed to a substantial meridional climate gradient (ranging from hyper-arid to humid-temperate conditions). We show that the warming occurring in the region from LGM to present, in addition to the increase of atmospheric CO2 concentrations, led to a shift in vegetation composition and surface cover. Future work will show how these changes resonate in the dynamics of hillslope and fluvial erosion and ultimately bi-directional feedback mechanisms of vegetation development and landscape evolution/ soil formation (see also companion presentation by Schmid et al., this session).

Experimental and field investigations on uprooting of riparian vegetation

NASA Astrophysics Data System (ADS)

Calvani, Giulio; Francalanci, Simona; Solari, Luca; Gumiero, Bruna

2017-04-01

The morphology of a river reach is the result of many processes involving the motion of sediment (erosion, transport and deposition), the hydrological regime and the development and growth of vegetation. River evolution in the presence of vegetation depends on establishment of pioneer woody riparian seedlings on bars, and consequently on either their survival or death. Flooding events can cause young vegetation mortality by uprooting (Corenblit et al., 2007). These processes, despite their important implications on river morphodynamics, have been poorly investigated in the past. Most of previous research focused on the mechanism of root breakage and on measuring the vegetation resistance to uprooting in the vertical direction, while few works considered the effect of flow direction on the uprooting process (Bywater-Reyes et al., 2015). In this work, we focused on vegetation uprooting due to flow and to bed erosion. We considered two different types of vegetation: Avena Sativa, grown from seeds in external boxes, was used to investigate instantaneous uprooting, and Salix Purpurea, collected in the field, for delayed uprooting (namely type I and type II mechanisms, according to Edmaier et al., 2011). The experiments were carried out in a 5 m long flume in the Hydraulic Laboratory in Florence. A 2 m long mobile bed was build inside the flume, and vegetation was arranged according to several configurations on it. Both types of vegetation were subject to constant discharges to investigate the effects of a general bed degradation in modifying the occurrence of uprooting. We also performed some experiments with Avena Sativa located in a fixed bed and subjected to an increasing flow discharge in order to simulate instantaneous uprooting due to the action of hydrodynamic forces. We measured flow velocity, flow discharge and water depth and characterized vegetation by stem and root diameter, height and root length. The experimental results have been interpreted in terms of a

Influence of food acidulants and antioxidant spices on the bioaccessibility of beta-carotene from selected vegetables.

PubMed

Veda, Supriya; Platel, Kalpana; Srinivasan, Krishnapura

2008-09-24

Four common food acidulants--amchur, lime, tamarind, and kokum--and two antioxidant spices--turmeric and onion--were examined for their influence on the bioaccessibility of beta-carotene from two fleshy and two leafy vegetables. Amchur and lime generally enhanced the bioaccessibility of beta-carotene from these test vegetables in many instances. Such an improved bioaccessibility was evident in both raw and heat-processed vegetables. The effect of lime juice was generally more pronounced than that of amchur. Turmeric significantly enhanced the bioaccessibility of beta-carotene from all of the vegetables tested, especially when heat-processed. Onion enhanced the bioaccessibility of beta-carotene from pressure-cooked carrot and amaranth leaf and from open-pan-boiled pumpkin and fenugreek leaf. Lime juice and the antioxidant spices turmeric and onion minimized the loss of beta-carotene during heat processing of the vegetables. In the case of antioxidant spices, improved bioaccessibility of beta-carotene from heat-processed vegetables is attributable to their role in minimizing the loss of this provitamin. Lime juice, which enhanced the bioaccessibility of this provitamin from both raw and heat-processed vegetables, probably exerted this effect by some other mechanism in addition to minimizing the loss of beta-carotene. Thus, the presence of food acidulants (lime juice/amchur) and antioxidant spices (turmeric/onion) proved to be advantageous in the context of deriving maximum beta-carotene from the vegetable sources.

Ecohydrological implications of aeolian sediment trapping by sparse vegetation in drylands

USGS Publications Warehouse

Gonzales, Howell B.; Ravi, Sujith; Li, Junran; Sankey, Joel B.

2018-01-01

Aeolian processes are important drivers of ecosystem dynamics in drylands, and important feedbacks exist among aeolian – hydrological processes and vegetation. The trapping of wind-borne sediments by vegetation may result in changes in soil properties beneath the vegetation, which, in turn, can alter hydrological and biogeochemical processes. Despite the relevance of aeolian transport to ecosystem dynamics, the interactions between aeolian transport and vegetation in shaping dryland landscapes where sediment distribution is altered by relatively rapid changes in vegetation composition such as shrub encroachment, is not well understood. Here, we used a computational fluid dynamics (CFD) modeling framework to investigate the sediment trapping efficiencies of vegetation canopies commonly found in a shrub-grass ecotone in the Chihuahuan Desert (New Mexico, USA) and related the results to spatial heterogeneity in soil texture and infiltration measured in the field. A CFD open-source software package was used to simulate aeolian sediment movement through three-dimensional architectural depictions of Creosote shrub (Larrea tridentata) and Black Grama grass (Bouteloua eriopoda) vegetation types. The vegetation structures were created using a computer-aided design software (Blender), with inherent canopy porosities, which were derived using LIDAR (Light Detection and Ranging) measurements of plant canopies. Results show that considerable heterogeneity in infiltration and soil grain size distribution exist between the microsites, with higher infiltration and coarser soil texture under shrubs. Numerical simulations also indicate that the differential trapping of canopies might contribute to the observed heterogeneity in soil texture. In the early stages of encroachment, the shrub canopies, by trapping coarser particles more efficiently, might maintain higher infiltration rates leading to faster development of the microsites (among other factors) with enhanced ecological

Integration of vegetation community spatial data into a prescribed fire planning process at Shenandoah National Park, Virginia (USA)

USGS Publications Warehouse

Young, John A.; Mahan, Carolyn G.; Forder, Melissa

2017-01-01

Many eastern forest communities depend on fire for regeneration or are enhanced by fire as a restoration practice. However, the use of prescribed fire in the mesic forested environments and the densely populated regions of the eastern United States has been limited. The objective of our research was to develop a science-based approach to prioritizing the use of prescribed fire in appropriate forest types in the eastern United States based on a set of desired management outcomes. Through a process of expert elicitation and data analysis, we assessed and integrated recent vegetation community mapping results along with other available spatial data layers into a spatial prioritization tool for prescribed fire planning at Shenandoah National Park (Virginia, USA). The integration of vegetation spatial data allowed for development of per-pixel priority rankings and exclusion areas enabling precise targeting of fire management activities on the ground, as well as a park-wide ranking of fire planning compartments. We demonstrate the use and evaluation of this approach through implementation and monitoring of a prescribed burn and show that progress is being made toward desired conditions. Integration of spatial data into the fire planning process has served as a collaborative tool for the implementation of prescribed fire projects, which assures projects will be planned in the most appropriate areas to meet objectives that are supported by current science.

Mapping forest vegetation with ERTS-1 MSS data and automatic data processing techniques

NASA Technical Reports Server (NTRS)

Messmore, J.; Copeland, G. E.; Levy, G. F.

1975-01-01

This study was undertaken with the intent of elucidating the forest mapping capabilities of ERTS-1 MSS data when analyzed with the aid of LARS' automatic data processing techniques. The site for this investigation was the Great Dismal Swamp, a 210,000 acre wilderness area located on the Middle Atlantic coastal plain. Due to inadequate ground truth information on the distribution of vegetation within the swamp, an unsupervised classification scheme was utilized. Initially pictureprints, resembling low resolution photographs, were generated in each of the four ERTS-1 channels. Data found within rectangular training fields was then clustered into 13 spectral groups and defined statistically. Using a maximum likelihood classification scheme, the unknown data points were subsequently classified into one of the designated training classes. Training field data was classified with a high degree of accuracy (greater than 95%), and progress is being made towards identifying the mapped spectral classes.

Mapping forest vegetation with ERTS-1 MSS data and automatic data processing techniques

NASA Technical Reports Server (NTRS)

Messmore, J.; Copeland, G. E.; Levy, G. F.

1975-01-01

This study was undertaken with the intent of elucidating the forest mapping capabilities of ERTS-1 MSS data when analyzed with the aid of LARS' automatic data processing techniques. The site for this investigation was the Great Dismal Swamp, a 210,000 acre wilderness area located on the Middle Atlantic coastal plain. Due to inadequate ground truth information on the distribution of vegetation within the swamp, an unsupervised classification scheme was utilized. Initially pictureprints, resembling low resolution photographs, were generated in each of the four ERTS-1 channels. Data found within rectangular training fields was then clustered into 13 spectral groups and defined statistically. Using a maximum likelihood classification scheme, the unknown data points were subsequently classified into one of the designated training classes. Training field data was classified with a high degree of accuracy (greater than 95 percent), and progress is being made towards identifying the mapped spectral classes.

Vegetation of the Elwha River estuary: Chapter 8 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

USGS Publications Warehouse

Shafroth, Patrick B.; Fuentes, Tracy L.; Pritekel, Cynthia; Beirne, Matthew M.; Beauchamp, Vanessa B.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

2011-01-01

The Elwha River estuary supports one of the most diverse coastal wetland complexes yet described in the Salish Sea region, in terms of vegetation types and plant species richness. Using a combination of aerial imagery and vegetation plot sampling, we identified 6 primary vegetation types and 121 plant species in a 39.7 ha area. Most of the estuary is dominated by woody vegetation types, with mixed riparian forest being the most abundant (20 ha), followed by riparian shrub (6.3 ha) and willow-alder forest (3.9 ha). The shrub-emergent marsh transition vegetation type was fourth most abundant (2.2 ha), followed by minor amounts of dunegrass (1.75 ha) and emergent marsh (0.2 ha). This chapter documents the abundance, distribution, and floristics of these six vegetation types, including plant species richness, life form, species origin (native or introduced), and species wetland indicator status. These data will serve as a baseline to which future changes can be compared, following the impending removal of Glines Canyon and Elwha Dams upstream on the Elwha River. Dam removals may alter many of the processes, materials, and biotic interactions that influence the estuary plant communities, including hydrology, salinity, sediment and wood transport, nutrients, and plant-microbe interactions.

New vegetable and fruit-vegetable juices treated by high pressure

NASA Astrophysics Data System (ADS)

Gabrovská, Dana; Ouhrabková, Jarmila; Rysová, Jana; Laknerová, Ivana; Fiedlerová, Vlasta; Holasová, Marie; Winterová, Renata; Průchová, Jiřina; Strohalm, Jan; Houška, Milan; Landfeld, Aleš; Erban, Vladimír; Eichlerová, Eva; Němečková, Irena; Kejmarová, Marie; Bočková, Pavlína

2012-03-01

The aim of this work was to find sensory suitable combinations of not commonly used vegetables, that is, cabbage, celeriac and parsnip, into mixed fruit-vegetable juices, two-species vegetable juices and vegetable juices with whey. These juices might have the potential to offer consumers new, interesting, tasty and nutritional products. Another interesting variation could be preparation of vegetable juices in combination with sweet whey. Nutritional and sensory evaluations were carried out using juices prepared in the laboratory. The total phenolic content, in addition to ascorbic acid and antioxidant activity, was determined. The developed juices with high nutritional value should increase very low fruit and vegetable consumption in the Czech population. The prepared juices were high pressure pasteurized (410 MPa). This technique retains the desired levels of important nutritional substances, while being destructive to live microbial cell structure. The germination of spores is suppressed by low pH value.

SPRUCE S1 Bog Vegetation Allometric and Biomass Data: 2010-2011

DOE Data Explorer

Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Brice, D. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Garten, C. T. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hook, L. A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Phillips, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Todd, D. E. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

2012-01-01

This data set reports the results of measurements on sampled aboveground tissues of trees (Picea mariana and Larix laricina), shrubs (Ledum, Chamaedaphne, and Vaccinium), and ground layer vegetation (all species) of the S1 Bog located in areas adjacent to planned experimental study plots. Ground layer vegetation was sampled from both hummocks and hollows, within a 0.25 m2 plot, to evaluate total standing biomass of bog vegetation at or near the peak of annual production. Vegetation was harvested, processed, and measured in July of 2010 and again in June of 2011.

Global validation of a process-based model on vegetation gross primary production using eddy covariance observations.

PubMed

Liu, Dan; Cai, Wenwen; Xia, Jiangzhou; Dong, Wenjie; Zhou, Guangsheng; Chen, Yang; Zhang, Haicheng; Yuan, Wenping

2014-01-01

Gross Primary Production (GPP) is the largest flux in the global carbon cycle. However, large uncertainties in current global estimations persist. In this study, we examined the performance of a process-based model (Integrated BIosphere Simulator, IBIS) at 62 eddy covariance sites around the world. Our results indicated that the IBIS model explained 60% of the observed variation in daily GPP at all validation sites. Comparison with a satellite-based vegetation model (Eddy Covariance-Light Use Efficiency, EC-LUE) revealed that the IBIS simulations yielded comparable GPP results as the EC-LUE model. Global mean GPP estimated by the IBIS model was 107.50±1.37 Pg C year(-1) (mean value ± standard deviation) across the vegetated area for the period 2000-2006, consistent with the results of the EC-LUE model (109.39±1.48 Pg C year(-1)). To evaluate the uncertainty introduced by the parameter Vcmax, which represents the maximum photosynthetic capacity, we inversed Vcmax using Markov Chain-Monte Carlo (MCMC) procedures. Using the inversed Vcmax values, the simulated global GPP increased by 16.5 Pg C year(-1), indicating that IBIS model is sensitive to Vcmax, and large uncertainty exists in model parameterization.

Synergistic effects of social support and self-efficacy on dietary motivation predicting fruit and vegetable intake.

PubMed

Reyes Fernández, Benjamín; Warner, Lisa Marie; Knoll, Nina; Montenegro Montenegro, Esteban; Schwarzer, Ralf

2015-04-01

Self-efficacy and social support are considered relevant predictors of fruit and vegetable intake. This study examines whether the effect of self-efficacy on fruit and vegetable intake is mediated by intention and whether this motivational process is moderated by received dietary social support. A longitudinal study with two measurement points in time, four weeks apart, on fruit and vegetable intake was carried out with 473 students aged 19 years on average (52% women). In a conditional process analysis, dietary intention was specified as a mediator between self-efficacy and fruit and vegetable intake, whereas received dietary support was specified as a moderator of the self-efficacy-intention association, controlling for baseline fruit and vegetable intake. Self-efficacy was positively associated with fruit and vegetable intake four weeks later, and intention mediated this process. Moreover, an interaction between received dietary support and self-efficacy on intention emerged. The effect of self-efficacy on fruit and vegetable intake was fully mediated by intention. Moreover, received support exhibited a moderating role within the motivational process: high dietary support appeared to accentuate the positive relationship between self-efficacy and dietary intention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vegetation in drylands: Effects on wind flow and aeolian sediment transport

USDA-ARS?s Scientific Manuscript database

Drylands are characterised by patchy vegetation, erodible surfaces and erosive aeolian processes. Empirical and modelling studies have shown that vegetation elements provide drag on the overlying airflow, thus affecting wind velocity profiles and altering erosive dynamics on desert surfaces. However...

[Efficiency evaluation of capsaicinoids to discriminate bio-waste oils from edible vegetable oils].

PubMed

Mao, Lisha; Liu, Honghe; Kang, Li; Jiang, Jie; Liao, Shicheng; Liu, Guihua; Deng, Pingjian

2014-07-01

To evaluate the efficiency of capsaicinoids to discriminate bio-waste oil from edible vegetable oil. 14 raw vegetable oils, 24 fried waste oils, 34 kitchen-waste oils, 32 edible non-peanut vegetable oil, 32 edible peanuts oil, 16 edible oil add flavorand and 11 refined bio-waste oils were prepared and examined for capsaicinoids including capsaicin, dihydrocapsaicin and nonylic acid vanillylamide. The detection results of the above samples were statistically tested based on sample category to assessment identify the effectiveness of the bio-waste oils with capsaicinoids. As a indicator, capsaincin was possessed of high detection sensitivity and has the highest efficiency to discern kitchen-waste oils and refined bio-waste oils samples from edible non-peanut vegetable oil correctly. The accuracy rate of identification were 100% and 90.1% respectively. There is the background in peanut oil. CONCLUSION Capsaicin added in cooking process can be retained in the refining process and hardly be removed in the refining process. In the case of fully eliminating the background interference, capsaicinoids can effectively identify bio-waste oils and edible vegetable oil in combination.

Interactions between river channel processes and riparian vegetation - an example from the Lužnice River, Czech Republic

NASA Astrophysics Data System (ADS)

Krejci, Lukas; Macka, Zdenek

2010-05-01

Riparian vegetation responds to hydrogemorphic processes and environmental changes and also controls these processes. Our study focuses on the interactions between woody riparian vegetation (live and dead trees) and river channel morphology on the example of three 1 km long reaches of the Lužnice River in southern Czech Republic. Here, we propose that despite spatial proximity, identical hydrological and sedimentological controls, three river reaches have different geomorphology due to varying character of riparian woody vegetation and different character and abundance of large in-stream wood (LW). Upstream, middle and downstream reaches vary markedly in channel dimensions (width, depth) and the present day rate of lateral erosion. Three reaches also show the different in-stream wood loads which are dependent mainly on the character of the riparian vegetation, and on the lateral activity of the channel. The highest wood load was recorded at the downstream reach with 102,162 m3/ha, the lowest at the middle reach 37,041 m3/ha, the upstream reach has load 81,370 m3/ha. Upper reach woody vegetation is the mixture of willow, alder, chokecherry and oak. The reach is only slightly sinuous with the moderate rate of incision and lateral erosion. The channel width and depth are 13 m and 2,1 m respectively, the mean cross section area is 27,3 m2. Erosion in the reach is slightly enhanced by the river training works upstream (canalisation, weir construction). Middle reach woody vegetation mostly consist of willow. Tree-tops often incline into the channel, thus, dissipating effectively the energy of the river flow. The reach is moderately sinuous and rather laterally stable. The channel width and depth are 10 m and 2,5 m respectively, the mean cross section area is 25 m2. The reach approximates the natural condition of the pristine river. The impact of river training works is minor only with the road bridge upstream. This reach in the most natural condition shows the lowest in

Enhancement of Antioxidant Quality of Green Leafy Vegetables upon Different Cooking Method

PubMed Central

Hossain, Afzal; Khatun, Mst. Afifa; Islam, Mahfuza; Huque, Roksana

2017-01-01

Antioxidant rich green leafy vegetables including garden spinach leaf, water spinach leaf, Indian spinach leaf, and green leaved amaranth were selected to evaluate the effects of water boiling and oil frying on their total phenolic content (TPC), total flavonoid content (TFC), reducing power (RP), and antioxidant capacity. The results revealed that there was a significant increase in TPC, TFC, and RP in all the selected vegetables indicating the effectiveness of the cooking process on the antioxidant potential of leafy vegetables. Both cooking processes enhanced significantly (P<0.05) the radical scavenging ability, especially the oil fried samples showed the highest values. There is a significant reduction in the vitamin C content in all the vegetables due to boiling and frying except in the Indian spinach leaf. However, the present findings suggest that boiling and frying can be used to enhance the antioxidant ability, by increasing the bioaccessibility of health-promoting constituents from the four vegetables investigated in this study. PMID:29043220

Application of the microbiological method DEFT/APC to detect minimally processed vegetables treated with gamma radiation

NASA Astrophysics Data System (ADS)

Araújo, M. M.; Duarte, R. C.; Silva, P. V.; Marchioni, E.; Villavicencio, A. L. C. H.

2009-07-01

Marketing of minimally processed vegetables (MPV) are gaining impetus due to its convenience, freshness and apparent health effect. However, minimal processing does not reduce pathogenic microorganisms to safe levels. Food irradiation is used to extend the shelf life and to inactivate food-borne pathogens. In combination with minimal processing it could improve safety and quality of MPV. A microbiological screening method based on the use of direct epifluorescent filter technique (DEFT) and aerobic plate count (APC) has been established for the detection of irradiated foodstuffs. The aim of this study was to evaluate the applicability of this technique in detecting MPV irradiation. Samples from retail markets were irradiated with 0.5 and 1.0 kGy using a 60Co facility. In general, with a dose increment, DEFT counts remained similar independent of the irradiation while APC counts decreased gradually. The difference of the two counts gradually increased with dose increment in all samples. It could be suggested that a DEFT/APC difference over 2.0 log would be a criteria to judge if a MPV was treated by irradiation. The DEFT/APC method could be used satisfactorily as a screening method for indicating irradiation processing.

Abrupt vegetation transitions characterise long-term Amazonian peatland development

NASA Astrophysics Data System (ADS)

Roucoux, K. H.; Baker, T. R.; Gosling, W. D.; Honorio Coronado, E.; Jones, T. D.; Lahteenoja, O.; Lawson, I. T.

2012-04-01

Recent investigations of wetlands in western Amazonia have revealed the presence of extensive peatlands with peat deposits of up to 8 m-thick developing under a variety of vegetation types (Lähteenoja et al. 2012). Estimated to cover 150,000 km2 (Schulman et al. 1999), these peatlands make a valuable contribution to landscape and biological diversity and represent globally important carbon stores. In order to understand the processes leading to peat formation, and the sensitivity of these environments to future climatic change, it is necessary to understand their long-term history. The extent to which peatland vegetation changes over time, the stability of particular communities, the controls on transitions between vegetation types and how these factors relate to the accumulation of organic matter are not yet known. We report the first attempt to establish the long-term (millennial scale) vegetation history of a recently-described peatland site: Quistococha, a palm swamp, or aguajal, close to Iquitos in northern Peru. The vegetation is dominated by Mauritia flexuosa and Mauritiella armata and occupies a basin which is thought to be an abandoned channel of the River Amazon. We obtained a 4 m-long peat sequence from the deepest part of the basin. AMS-radiocarbon dating yielded a maximum age of 2,212 cal yr BP for the base of the peat, giving an average accumulation rate of 18 cm per century. Below the peat are 2 m of uniform, largely inorganic pale grey clays of lacustrine origin, which are underlain by an unknown thickness of inorganic sandy-silty clay of fluvial origin. Pollen analysis, carried out at c. 88-year intervals, shows the last 2,212 years to be characterised by the development of at least four distinct vegetation communities, with peat accumulating throughout. The main phases were: (1) Formation of Cyperaceae (sedge) fen coincident with peat initiation; (2) A short-lived phase of local Mauritia/Mauritiella development; (3) Development of mixed wet

Projected future vegetation changes for the northwest United States and southwest Canada at a fine spatial resolution using a dynamic global vegetation model.

USGS Publications Warehouse

Shafer, Sarah; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.

2015-01-01

Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.

Projected Future Vegetation Changes for the Northwest United States and Southwest Canada at a Fine Spatial Resolution Using a Dynamic Global Vegetation Model

PubMed Central

Shafer, Sarah L.; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.

2015-01-01

Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas. PMID:26488750

Projected Future Vegetation Changes for the Northwest United States and Southwest Canada at a Fine Spatial Resolution Using a Dynamic Global Vegetation Model.

PubMed

Shafer, Sarah L; Bartlein, Patrick J; Gray, Elizabeth M; Pelltier, Richard T

2015-01-01

Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0-58.0°N latitude by 136.6-103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070-2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.

Parameterization of sparse vegetation in thermal images of natural ground landscapes

NASA Astrophysics Data System (ADS)

Agassi, Eyal; Ben-Yosef, Nissim

1997-10-01

The radiant statistics of thermal images of desert terrain scenes and their temporal behavior have been fully understood and well modeled. Unlike desert scenes, most natural terrestrial landscapes contain vegetative objects. A plant is a living object that regulates its temperature through evapotranspiration of leaf stomata, and plant interaction with the outside world is influenced by its physiological processes. Therefore, the heat balance equation for a vegetative object differs from that for an inorganic surface element. Despite this difficulty, plants can be incorporated into the desert surface model when an effective heat conduction parameter is associated with vegetation. Due to evapotranspiration, the effective heat conduction of plants during daytime is much higher than at night. As a result, plants (mainly trees and bushes) are usually the coldest objects in the scene in the daytime while they are not necessarily the warmest objects at night. The parameterization of vegetative objects in terms of effective heat conduction enables the extension of the desert terrain model for scenes with sparse vegetation and the estimation of their radiant statistics and their diurnal behavior. The effective heat conduction image can serve as a tool for vegetation type classification and assessment of the dominant physical process that determinate thermal image properties.

Masking Vegetable Bitterness to Improve Palatability Depends on Vegetable Type and Taste Phenotype

PubMed Central

2013-01-01

Consumption of dark green vegetables falls short of recommendations, in part, because of unpleasant bitterness. A laboratory-based study of 37 adults was used to determine bitter and hedonic responses to vegetables (asparagus, Brussels sprouts, kale) with bitter masking agents (1.33 M sodium acetate, 10 and 32 mM sodium chloride, and 3.2 mM aspartame) and then characterized by taste phenotype and vegetable liking. In repeated-measures ANOVA, aspartame was most effective at suppressing bitterness and improving hedonic responses for all sampled vegetables. Among the sodium salts, 32 mM sodium chloride decreased bitterness for kale and sodium acetate reduced bitterness across all vegetables with a tendency to increase liking for Brussels sprouts, as release from mixture suppression increased perceived sweetness. Participants were nearly equally divided into three 6-n-propylthiouracil (PROP) phenotype groups. Those tasting the least PROP bitterness (non-tasters) reported least vegetable bitterness, and the additives produced little change in vegetable liking. Aspartame persisted as the most effective bitter blocker for the PROP tasters (medium, supertasters), improving vegetable liking for the medium tasters but too much sweetness for supertasters. The sodium salts showed some bitter blocking for PROP tasters, particularly sodium acetate, without significant gains in vegetable liking. Via a survey, adults characterized as low vegetable likers reported greater increase in vegetable liking with the maskers than did vegetable likers. These results suggest that bitter masking agents (mainly sweeteners) can suppress bitterness to increase acceptance if they are matched to perceived vegetable bitterness or to self-reported vegetable disliking. PMID:23682306

Long-term monitoring of stream bank stability under different vegetation cover

NASA Astrophysics Data System (ADS)

Krzeminska, Dominika; Skaalsveen, Kamilla; Kerkhof, Tjibbe

2017-04-01

Vegetated buffer zones are common environmental measures in many countries, including Norway. The presence of riparian vegetation on stream banks not only provides ecological benefits but also influence bank slope stability, through several complex interactions between riparian vegetation and hydro - mechanical processes. The hydrological processes associated with slope stability are complex and yet difficult to quantify, especially because their transient effects (e.g. changes throughout the vegetation life cycle). Additionally, there is very limited amount of field scale research focusing on investigation of coupled hydrological and mechanical influence of vegetation on stream bank behavior, accounting for both seasonal time scale and different vegetation type, and none dedicated to marine clay soils (typically soil for Norway). In order to fill this gap we established continues, long term hydrogeological monitoring o selected cross - section within stream bank, covered with different types of vegetation, typical for Norwegian agriculture areas (grass, shrubs, and trees). The monitoring involves methods such as spatial and temporal monitoring of soil moisture conditions, ground water level and fluctuation of water level in the stream. Herein we will present first 10 months of monitoring data: observed hydrological trends and differences between three cross - sections. Moreover, we will present first modelling exercises that aims to estimate stream banks stability with accounting on presence of different vegetation types using BSTEM and HYDRUS models. With this presentation, we would like to stimulate the discussion and get feedback that could help us to improve both, our experimental set up and analysis approach.

77 FR 9637 - Process for Requesting a Variance From Vegetation Standards for Levees and Floodwalls; Additional...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...-2502, Retaining and Flood Walls, 29 September 1989. h. Engineer Technical Letter (ETL) 1110-2-575... vegetation variance request. h. All final documentation for the vegetation variance request shall be uploaded..., especially for I-walls of concern as identified per Paragraph 3.h. For floodwalls, the landside and waterside...

Classification of wetlands vegetation using small scale color infrared imagery

NASA Technical Reports Server (NTRS)

Williamson, F. S. L.

1975-01-01

A classification system for Chesapeake Bay wetlands was derived from the correlation of film density classes and actual vegetation classes. The data processing programs used were developed by the Laboratory for the Applications of Remote Sensing. These programs were tested for their value in classifying natural vegetation, using digitized data from small scale aerial photography. Existing imagery and the vegetation map of Farm Creek Marsh were used to determine the optimal number of classes, and to aid in determining if the computer maps were a believable product.

Theory, methods and tools for determining environmental flows for riparian vegetation: Riparian vegetation-flow response guilds

USGS Publications Warehouse

Merritt, D.M.; Scott, M.L.; Leroy, Poff N.; Auble, G.T.; Lytle, D.A.

2010-01-01

Riparian vegetation composition, structure and abundance are governed to a large degree by river flow regime and flow-mediated fluvial processes. Streamflow regime exerts selective pressures on riparian vegetation, resulting in adaptations (trait syndromes) to specific flow attributes. Widespread modification of flow regimes by humans has resulted in extensive alteration of riparian vegetation communities. Some of the negative effects of altered flow regimes on vegetation may be reversed by restoring components of the natural flow regime. 2. Models have been developed that quantitatively relate components of the flow regime to attributes of riparian vegetation at the individual, population and community levels. Predictive models range from simple statistical relationships, to more complex stochastic matrix population models and dynamic simulation models. Of the dozens of predictive models reviewed here, most treat one or a few species, have many simplifying assumptions such as stable channel form, and do not specify the time-scale of response. In many cases, these models are very effective in developing alternative streamflow management plans for specific river reaches or segments but are not directly transferable to other rivers or other regions. 3. A primary goal in riparian ecology is to develop general frameworks for prediction of vegetation response to changing environmental conditions. The development of riparian vegetation-flow response guilds offers a framework for transferring information from rivers where flow standards have been developed to maintain desirable vegetation attributes, to rivers with little or no existing information. 4. We propose to organise riparian plants into non-phylogenetic groupings of species with shared traits that are related to components of hydrologic regime: life history, reproductive strategy, morphology, adaptations to fluvial disturbance and adaptations to water availability. Plants from any river or region may be grouped

Global relation between microwave satellite vegetation products and vegetation productivity

NASA Astrophysics Data System (ADS)

Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Miralles, Diego G.; Dorigo, Wouter A.

2017-04-01

The occurrence of unfavourable environmental conditions like droughts commonly reduces the photosynthetic activity of ecosystems and, hence, their potential to take up carbon from the atmosphere. Ecosystem photosynthetic activity is commonly determined using remote sensing observations in the optical domain, which however have limitations particularly in regions of frequent cloud cover, e.g. the tropics. In this study, we explore the potential of vegetation optical depth (VOD) from microwave satellite observations as an alternative source for assessing vegetation productivity. VOD serves as an estimate for vegetation density and water content, which has an impact on plant physiological processes and hence should potentially provide a link to gross primary production (GPP). However, to date, it is unclear how microwave-retrieved VOD data and GPP data are related. We compare seasonal dynamics and anomalies of VOD retrievals from different satellite sensors and microwave frequencies with site level and global GPP estimates. We use VOD observations from active (ASCAT) and passive microwave sensors (AMSR-E, SMOS). We include eddy covariance measurements from the FLUXNET2015 dataset to assess the VOD products at site level. For a global scale analysis, we use the solar-induced chlorophyll fluorescence (SIF) observations from GOME-2 as a proxy for GPP and the FLUXCOM GPP product, which presents an upscaling of site measurements based on remote sensing data. Our results demonstrate that in general a good agreement between VOD and GPP or SIF exists. However, the strength of these relations depends on the microwave frequency, land cover type, and the time within the growing season. Correlations between anomalies of VOD and GPP or SIF support the assumption that microwave-derived VOD can be used to monitor vegetation productivity dynamics. The study is performed as part of the EOWAVE project funded by the Vienna University of Technology (http://eowave.geo.tuwien.ac.at/) and

A New Vegetation Segmentation Approach for Cropped Fields Based on Threshold Detection from Hue Histograms

PubMed Central

Hassanein, Mohamed; El-Sheimy, Naser

2018-01-01

Over the last decade, the use of unmanned aerial vehicle (UAV) technology has evolved significantly in different applications as it provides a special platform capable of combining the benefits of terrestrial and aerial remote sensing. Therefore, such technology has been established as an important source of data collection for different precision agriculture (PA) applications such as crop health monitoring and weed management. Generally, these PA applications depend on performing a vegetation segmentation process as an initial step, which aims to detect the vegetation objects in collected agriculture fields’ images. The main result of the vegetation segmentation process is a binary image, where vegetations are presented in white color and the remaining objects are presented in black. Such process could easily be performed using different vegetation indexes derived from multispectral imagery. Recently, to expand the use of UAV imagery systems for PA applications, it was important to reduce the cost of such systems through using low-cost RGB cameras Thus, developing vegetation segmentation techniques for RGB images is a challenging problem. The proposed paper introduces a new vegetation segmentation methodology for low-cost UAV RGB images, which depends on using Hue color channel. The proposed methodology follows the assumption that the colors in any agriculture field image can be distributed into vegetation and non-vegetations colors. Therefore, four main steps are developed to detect five different threshold values using the hue histogram of the RGB image, these thresholds are capable to discriminate the dominant color, either vegetation or non-vegetation, within the agriculture field image. The achieved results for implementing the proposed methodology showed its ability to generate accurate and stable vegetation segmentation performance with mean accuracy equal to 87.29% and standard deviation as 12.5%. PMID:29670055

Modelling post-fire vegetation recovery in Portugal

NASA Astrophysics Data System (ADS)

Bastos, A.; Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

2011-05-01

Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 yr (1998-2009), at 1 × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In what respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus Pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland

Modelling post-fire vegetation recovery in Portugal

NASA Astrophysics Data System (ADS)

Bastos, A.; Gouveia, C. M.; Dacamara, C. C.; Trigo, R. M.

2011-12-01

Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 years (1998-2009), at 1 km × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland

Estimating Vegetation Structure in African Savannas using High Spatial Resolution Imagery

NASA Astrophysics Data System (ADS)

Axelsson, C.; Hanan, N. P.

2016-12-01

High spatial resolution satellite imagery allows for detailed mapping of trees in savanna landscapes, including estimates of woody cover, tree densities, crown sizes, and the spatial pattern of trees. By linking these vegetation parameters to rainfall and soil properties we gain knowledge of how the local environment influences vegetation. A thorough understanding of the underlying ecosystem processes is key to assessing the future productivity and stability of these ecosystems. In this study, we have processed and analyzed hundreds of sites sampled from African savannas across a wide range of rainfall and soil conditions. The vegetation at each site is classified using unsupervised classification with manual assignment into woody, herbaceous and bare cover classes. A crown delineation method further divides the woody areas into individual tree crowns. The results show that rainfall, soil, and topography interactively influence vegetation structure. We see that both total rainfall and rainfall seasonality play important roles and that soil type influences woody cover and the sizes of tree crowns.

A LANDSAT study of ephemeral and perennial rangeland vegetation and soils

NASA Technical Reports Server (NTRS)

Bentley, R. G., Jr. (Principal Investigator); Salmon-Drexler, B. C.; Bonner, W. J.; Vincent, R. K.

1976-01-01

The author has identified the following significant results. Several methods of computer processing were applied to LANDSAT data for mapping vegetation characteristics of perennial rangeland in Montana and ephemeral rangeland in Arizona. The choice of optimal processing technique was dependent on prescribed mapping and site condition. Single channel level slicing and ratioing of channels were used for simple enhancement. Predictive models for mapping percent vegetation cover based on data from field spectra and LANDSAT data were generated by multiple linear regression of six unique LANDSAT spectral ratios. Ratio gating logic and maximum likelihood classification were applied successfully to recognize plant communities in Montana. Maximum likelihood classification did little to improve recognition of terrain features when compared to a single channel density slice in sparsely vegetated Arizona. LANDSAT was found to be more sensitive to differences between plant communities based on percentages of vigorous vegetation than to actual physical or spectral differences among plant species.

Towards an understanding of coupled physical and biological processes in the cultivated Sahel - 2. Vegetation and carbon dynamics

NASA Astrophysics Data System (ADS)

Boulain, N.; Cappelaere, B.; Ramier, D.; Issoufou, H. B. A.; Halilou, O.; Seghieri, J.; Guillemin, F.; Oï, M.; Gignoux, J.; Timouk, F.

2009-08-01

SummaryThis paper analyses the dynamics of vegetation and carbon during the West African monsoon season, for millet crop and fallow vegetation covers in the cultivated area of the Sahel. Comparing these two dominant land cover types informs on the impact of cultivation on productivity and carbon fluxes. Biomass, leaf area index (LAI) and carbon fluxes were monitored over a 2-year period for these two vegetation systems in the Wankama catchment of the AMMA (African monsoon multidisciplinary analyses) experimental super-site in West Niger. Carbon fluxes and water use efficiency observed at the field scale are confronted with ecophysiological measurements (photosynthetic response to light, and relation of water use efficiency to air humidity) made at the leaf scale for the dominant plant species in the two vegetation systems. The two rainy seasons monitored were dissimilar with respect to rain patterns, reflecting some of the interannual variability. Distinct responses in vegetation development and in carbon dynamics were observed between the two vegetation systems. Vegetation development in the fallow was found to depend more on rainfall distribution along the season than on its starting date. A quite opposite behaviour was observed for the crop vegetation: the date of first rain appears as a principal factor of millet growth. Carbon flux exchanges were well correlated to vegetation development. High responses of photosynthesis to light were observed for the dominant herbaceous and shrub species of the fallow at the leaf and field scales. Millet showed high response at the leaf scale, but a much lesser response at the field scale. This pattern, also observed for water use efficiency, is to be related to the low density of the millet cover. A simple LAI-based model for scaling up the photosynthetic response from leaf to field scale was found quite successful for the fallow, but was less conclusive for the crop, due to spatial variability of LAI. Time/space variations

Endogenous knowledge of four leafy vegetables used by rural populations in Benin.

PubMed

Vihotogbe-Sossa, Carole N A; Akissoe, Noël H; Anihouvi, Victor B; Ahohuendo, Bonaventure C; Ahanchede, Adam; Sanni, Ambaliou; Hounhouigan, D Joseph

2012-01-01

Leafy vegetables are sources of diet diversification and could contribute to food and nutritional security in African rural areas. However, in some places, little is known about if, how, and why leafy vegetables are consumed. Processing and preservation methods, food forms, and consumption determinants of four leafy vegetables (Sesamum radiatum, Ceratotheca sesamoïdes, Acmella uliginosa and Justicia tenella), known to contribute to the diet of rural populations in the Center and Northern parts of Benin, were investigated. Three hundred randomly selected households were investigated, using rapid appraisal and quantitative survey methods, descriptive statistics and correspondence analysis. Processing methods to prepare sauces varied depending on sociocultural groups. Cooking of fresh leaves predominated, while sun drying was the usual practice of preserving these leafy vegetables. Consumption frequencies were associated with sociocultural groups, food habits, and availability in living areas.

Advances in postharvest technologies to extend the storage life of minimally processed fruits and vegetables.

PubMed

Ali, Asgar; Yeoh, Wei Keat; Forney, Charles; Siddiqui, Mohammed Wasim

2017-10-26

Minimally processed fresh produce is one of the fastest growing segments of the food industry due to consumer demand for fresh, healthy, and convenient foods. However, mechanical operations of cutting and peeling induce the liberation of cellular contents at the site of wounding that can promote the growth of pathogenic and spoilage microorganisms. In addition, rates of tissue senescence can be enhanced resulting in reduced storage life of fresh-cut fruits and vegetables. Chlorine has been widely adopted in the disinfection and washing procedures of fresh-cut produce due to its low cost and efficacy against a broad spectrum of microorganisms. Continuous replenishment of chlorine in high organic wash water can promote the formation of carcinogenic compounds such as trihalomethanes, which threaten human and environmental health. Alternative green and innovative chemical and physical postharvest treatments such as ozone, electrolyzed water, hydrogen peroxide, ultraviolet radiation, high pressure processing, and ultrasound can achieve similar reduction of microorganisms as chlorine without the production of harmful compounds or compromising the quality of fresh-cut produce.

Patterns in woody vegetation structure across African savannas

NASA Astrophysics Data System (ADS)

Axelsson, Christoffer R.; Hanan, Niall P.

2017-07-01

Vegetation structure in water-limited systems is to a large degree controlled by ecohydrological processes, including mean annual precipitation (MAP) modulated by the characteristics of precipitation and geomorphology that collectively determine how rainfall is distributed vertically into soils or horizontally in the landscape. We anticipate that woody canopy cover, crown density, crown size, and the level of spatial aggregation among woody plants in the landscape will vary across environmental gradients. A high level of woody plant aggregation is most distinct in periodic vegetation patterns (PVPs), which emerge as a result of ecohydrological processes such as runoff generation and increased infiltration close to plants. Similar, albeit weaker, forces may influence the spatial distribution of woody plants elsewhere in savannas. Exploring these trends can extend our knowledge of how semi-arid vegetation structure is constrained by rainfall regime, soil type, topography, and disturbance processes such as fire. Using high-spatial-resolution imagery, a flexible classification framework, and a crown delineation method, we extracted woody vegetation properties from 876 sites spread over African savannas. At each site, we estimated woody cover, mean crown size, crown density, and the degree of aggregation among woody plants. This enabled us to elucidate the effects of rainfall regimes (MAP and seasonality), soil texture, slope, and fire frequency on woody vegetation properties. We found that previously documented increases in woody cover with rainfall is more consistently a result of increasing crown size than increasing density of woody plants. Along a gradient of mean annual precipitation from the driest (< 200 mm yr-1) to the wettest (1200-1400 mm yr-1) end, mean estimates of crown size, crown density, and woody cover increased by 233, 73, and 491 % respectively. We also found a unimodal relationship between mean crown size and sand content suggesting that maximal

[Object-oriented aquatic vegetation extracting approach based on visible vegetation indices.

PubMed

Jing, Ran; Deng, Lei; Zhao, Wen Ji; Gong, Zhao Ning

2016-05-01

Using the estimation of scale parameters (ESP) image segmentation tool to determine the ideal image segmentation scale, the optimal segmented image was created by the multi-scale segmentation method. Based on the visible vegetation indices derived from mini-UAV imaging data, we chose a set of optimal vegetation indices from a series of visible vegetation indices, and built up a decision tree rule. A membership function was used to automatically classify the study area and an aquatic vegetation map was generated. The results showed the overall accuracy of image classification using the supervised classification was 53.7%, and the overall accuracy of object-oriented image analysis (OBIA) was 91.7%. Compared with pixel-based supervised classification method, the OBIA method improved significantly the image classification result and further increased the accuracy of extracting the aquatic vegetation. The Kappa value of supervised classification was 0.4, and the Kappa value based OBIA was 0.9. The experimental results demonstrated that using visible vegetation indices derived from the mini-UAV data and OBIA method extracting the aquatic vegetation developed in this study was feasible and could be applied in other physically similar areas.

Green vegetation, nonphotosynthetic vegetation, and soils in AVIRIS data

NASA Technical Reports Server (NTRS)

Roberts, D. A.; Smith, M. O.; Adams, J. B.

1993-01-01

The problem of distinguishing between green vegetation, nonphotosynthetic vegetation (NPV, such as dry grass, leaf litter, and woody material), and soils in imaging-spectrometer data is addressed by analyzing an image taken by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) over the Jasper Ridge Biological Preserve (California) on September 20, 1989, using spectral mixture analysis. Over 98 percent of the spectral variation could be explained by linear mixtures of three endmembers, green vegetation, shade, and soil. NPV, which could not be distinguished from soil when included as an endmember, was discriminated by residual spectra that contained cellulose and lignin absorptions. Distinct communities of green vegetation were distinguished by (1) nonlinear mixing effect caused by transmission and scattering by green leaves, (2) variations in a derived canopy-shade spectrum, and (3) the fraction of NPV.

Possible causes of Arctic Tundra Vegetation Productivity Declines

NASA Astrophysics Data System (ADS)

Bhatt, U. S.; Walker, D. A.; Raynolds, M. K.; Bieniek, P.; Epstein, H. E.; Comiso, J. C.; Pinzon, J. E.; Tucker, C. J.

2017-12-01

Three decades of remotely sensed Normalized Difference Vegetation Index (NDVI) data document an overall increase in Arctic tundra vegetation greenness but the trends display considerable spatial variability. Pan-Arctic tundra vegetation greening is associated with increases in summer warmth that are, in large-part, driven by summer sea-ice retreat along Arctic coasts. Trends covering the period 1982-2016 are overall positive for summer open water, Summer Warmth Index (SWI, the sum of the degree months above zero from May-August), MaxNDVI (peak NDVI) and time integrated NDVI (TI-NDVI, sum of biweekly NDVI above 0.05 from May-September). Upon closer examination, it is clear that not all regions have positive trends, for example, there is an area of cooling in western Eurasia, which is broadly co-located with maxNDVI and TI-NDVI declines. While sea ice decline has continued over the satellite record, summer landsurface temperatures and vegetation productivity measures have not simply increased. Regional differences between warming and greening trends suggest that it is likely that multiple processes influence vegetation productivity beyond secular greening with increased summer warmth. This paper will present Pan-Arctic and regional analyses of the NDVI data in the context of climate drivers. Other possible drivers of vegetation productivity decline will be discussed such as increased standing water, delayed spring snow-melt, and winter thaw events. The status and limitations of data sets and modeling needed to advance our understanding of tundra vegetation productivity will be summarized and will serve as a starting point for planning the next steps in this topic. Methodical multi-disciplinary synthesis research that jointly considers vegetation type, permafrost conditions, altitude, as well as climate factors such as temperature, heat and moisture transport, and timing of snowfall and spring snowmelt is needed to better understand recent tundra vegetation

Examination of the semi-automatic calculation technique of vegetation cover rate by digital camera images.

NASA Astrophysics Data System (ADS)

Takemine, S.; Rikimaru, A.; Takahashi, K.

The rice is one of the staple foods in the world High quality rice production requires periodically collecting rice growth data to control the growth of rice The height of plant the number of stem the color of leaf is well known parameters to indicate rice growth Rice growth diagnosis method based on these parameters is used operationally in Japan although collecting these parameters by field survey needs a lot of labor and time Recently a laborsaving method for rice growth diagnosis is proposed which is based on vegetation cover rate of rice Vegetation cover rate of rice is calculated based on discriminating rice plant areas in a digital camera image which is photographed in nadir direction Discrimination of rice plant areas in the image was done by the automatic binarization processing However in the case of vegetation cover rate calculation method depending on the automatic binarization process there is a possibility to decrease vegetation cover rate against growth of rice In this paper a calculation method of vegetation cover rate was proposed which based on the automatic binarization process and referred to the growth hysteresis information For several images obtained by field survey during rice growing season vegetation cover rate was calculated by the conventional automatic binarization processing and the proposed method respectively And vegetation cover rate of both methods was compared with reference value obtained by visual interpretation As a result of comparison the accuracy of discriminating rice plant areas was increased by the proposed

Current issues and uncertainties in the measurement and modelling of air-vegetation exchange and within-plant processing of POPs.

PubMed

Barber, Jonathan L; Thomas, Gareth O; Kerstiens, Gerhard; Jones, Kevin C

2004-01-01

Air-vegetation exchange of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the air-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on air/plant exchange of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of air-vegetation exchange do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of air-plant exchange and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons

The Role of Vegetation Cover in Interactions between Climate and Erosion

NASA Astrophysics Data System (ADS)

Schildgen, T. F.; Torres-Acosta, V.; Düsing, W.; Garcin, Y.; Strecker, M. R.

2016-12-01

Interactions between tectonics, climate and erosion during mountain building are often considered to include a positive feedback between precipitation and erosion, with the onset of orographic rainfall inducing greater erosion, which in turn may drive faster deformation. Here, we consider two different case studies that explore specifically the relationship between climate and erosion. Within the Kenya Rift of East Africa, spatial variations in 10Be derived erosion rates show no clear dependency on yearly precipitation. Instead, we find that the data fall into two categories. In areas that are sparsely vegetated, erosion rates increase rapidly with slope, whereas in areas that are densely vegetated, erosion rates increase slowly with slope. These data imply that vegetation cover plays a major role in stabilizing hillslopes. From these results, we hypothesize that in a sparsely vegetated region, the onset of greater precipitation will lead to faster erosion, but only until vegetation becomes denser, after which erosion rates will strongly decrease. Initial results from an ongoing study that reconstruct paleo-erosion rates from a sedimentary archive support this hypothesis. Hence, we infer that in this region, vegetation cover acts as a negative feedback in the interactions between climate and erosion. Compared to East Africa, we find a very different relationship between climate and 10Be derived erosion rates in the Toro intermontane basin in NW Argentina. There, the fastest erosion rates occur in the wettest areas with dense vegetation cover, implying a positive feedback between increased precipitation and erosion rates. Also, paleo-erosion rates from the nearby Humahuaca Basin derived from fluvial terraces point to faster erosion during wetter periods in the past. In this region, the stabilizing effects of vegetation cover may be muted. Ultimately, whether increased precipitation leads to faster or slower erosion could hinge on the dominant erosion processes

Investigation of North American Vegetation Variability under Recent Climate: A Study Using the SSiB4/TRIFFID Biophysical/Dynamic Vegetation Model

NASA Technical Reports Server (NTRS)

Zhang, Zhengqiu; Xue, Yongkang; MacDonald, Glen; Cox, Peter M.; Collatz, George J.

2015-01-01

s. The effects of the severe drought during 1987-1992 and the last decade in the southwestern U.S. on vegetation are also evident from decreases in the simulated and satellite-derived LAIs. Both simulated and satellite-derived LAIs have the strongest correlations with air temperature at northern middle to high latitudes in spring reflecting the effect of these climatic variables on photosynthesis and phenological processes. Meanwhile, in southwestern dry lands, negative correlations appear due to the heat and moisture stress there during the summer. Furthermore, there are also positive correlations between soil wetness and LAI, which increases from spring to summer. The present study shows both the current improvements and remaining weaknesses in dynamical vegetation models. It also highlights large continental-scale variations that have occurred in NA vegetation over the past six decades and their potential relations to climate. With more observational data availability, more studies with differentmodels and focusing on different regions will be possible and are necessary to achieve comprehensive understanding of the vegetation dynamics and climate interactions.

The Alaska vegetation classification.

Treesearch

L.A. Viereck; C.T. Dyrness; A.R. Batten; K.J. Wenzlick

1992-01-01

The Alaska vegetation classification presented here is a comprehensive, statewide system that has been under development since 1976. The classification is based, as much as possible, on the characteristics of the vegetation itself and is designed to categorize existing vegetation, not potential vegetation. A hierarchical system with five levels of resolution is used...

Vegetable oils and animal fats for diesel fuels: a systems study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lipinsky, E.S.; Kresovich, S.; Wagner, C.K.

1982-01-01

This paper provided some information on the possible use of vegetable oils and animal fats as substitute fuels and as emergency diesel fuels in the United States. This paper is confined to using triglyceride fuels in agricultural, automotive, and highway transportation applications. Satisfactory substitution of petroleum-based diesel fuels with triglyceride-based fuels requires the development of an integrated system for the production, processing, and end use of the new fuels on a basis that is both technically attractive and economically rewarding to all of the elements of the system. The three subsystems, the farms that produce oilseed crops, the production ofmore » triglycerides and protein, and the manufacturers of the diesel engines and the owners of the present stock of auto-ignition engines, are discussed. It was concluded that vegetable oils and animal fats have substantial prospects as long-term substitutes for diesel fuels. If special auto-ignition engines were developed to handle vegetable oils, on-farm production and use might succeed. In the absence of such engine development, it is likely that large, centralized facilities to manufacture vegetable oils and their methylesters will be the successful processing route. Vegetable oils are likely to succeed first in geographical areas with benign climates. Vegetable oils and animal fats have limited prospects as diesel fuels for acute emergencies. The high viscosity of vegetable oils and the necessity to make substantial capital investments to obtain oils from oilseeds render the system relatively inflexible. 4 tables. (DP)« less

Stochastic simulation of ecohydrological interactions between vegetation and groundwater

NASA Astrophysics Data System (ADS)

Dwelle, M. C.; Ivanov, V. Y.; Sargsyan, K.

2017-12-01

The complex interactions between groundwater and vegetation in the Amazon rainforest may yield vital ecophysiological interactions in specific landscape niches such as buffering plant water stress during dry season or suppression of water uptake due to anoxic conditions. Representation of such processes is greatly impacted by both external and internal sources of uncertainty: inaccurate data and subjective choice of model representation. The models that can simulate these processes are complex and computationally expensive, and therefore make it difficult to address uncertainty using traditional methods. We use the ecohydrologic model tRIBS+VEGGIE and a novel uncertainty quantification framework applied to the ZF2 watershed near Manaus, Brazil. We showcase the capability of this framework for stochastic simulation of vegetation-hydrology dynamics. This framework is useful for simulation with internal and external stochasticity, but this work will focus on internal variability of groundwater depth distribution and model parameterizations. We demonstrate the capability of this framework to make inferences on uncertain states of groundwater depth from limited in situ data, and how the realizations of these inferences affect the ecohydrological interactions between groundwater dynamics and vegetation function. We place an emphasis on the probabilistic representation of quantities of interest and how this impacts the understanding and interpretation of the dynamics at the groundwater-vegetation interface.

Object-based vegetation classification with high resolution remote sensing imagery

NASA Astrophysics Data System (ADS)

Yu, Qian

Vegetation species are valuable indicators to understand the earth system. Information from mapping of vegetation species and community distribution at large scales provides important insight for studying the phenological (growth) cycles of vegetation and plant physiology. Such information plays an important role in land process modeling including climate, ecosystem and hydrological models. The rapidly growing remote sensing technology has increased its potential in vegetation species mapping. However, extracting information at a species level is still a challenging research topic. I proposed an effective method for extracting vegetation species distribution from remotely sensed data and investigated some ways for accuracy improvement. The study consists of three phases. Firstly, a statistical analysis was conducted to explore the spatial variation and class separability of vegetation as a function of image scale. This analysis aimed to confirm that high resolution imagery contains the information on spatial vegetation variation and these species classes can be potentially separable. The second phase was a major effort in advancing classification by proposing a method for extracting vegetation species from high spatial resolution remote sensing data. The proposed classification employs an object-based approach that integrates GIS and remote sensing data and explores the usefulness of ancillary information. The whole process includes image segmentation, feature generation and selection, and nearest neighbor classification. The third phase introduces a spatial regression model for evaluating the mapping quality from the above vegetation classification results. The effects of six categories of sample characteristics on the classification uncertainty are examined: topography, sample membership, sample density, spatial composition characteristics, training reliability and sample object features. This evaluation analysis answered several interesting scientific questions

[Effects of strong reductive process on transformation of heavy metals in protected vegetable soil].

PubMed

Sun, Yan Chen; Zeng, Xiang Feng; Yang, Li Qiong; Shi, Ya Nan; Chen, Xi Juan; Zhuang, Jie

2017-11-01

The application of sewage and manure in protected vegetable cultivation can induce the occurrence of heavy metals contamination. The present research studied the transformation of heavy metals (Cd, Cu, Pb and Zn) by incubating contaminated protected soil with maize straw and then leaching. The results showed that soil pH was significantly decreased, being more evident in maize straw treatment; soil Eh dropped quickly below -280 mV. Maize straw treatment promoted the activation of Cd, Cu, Pb and Zn from soil, and the total percent of oxidizable fraction and residual fraction of Cd, Cu, Pb and Zn declined at 9 th day; the amount of Cd, Cu, Pb and Zn in soil reduced 18.1%, 19.0%, 16.1% and 15.7% at 15 th day, respectively. Compared to control, maize straw treatment could increase the concentrations of dissolved Cd and Zn, but Cu decreased. The concentration of colloidal-bound Cd and Pb increased, Cu decreased and no significant change occurred in Zn in maize straw treatment. Strong reductive approach could activate heavy metals in protected vegetable soil, increase the risk of heavy metals accumulation in vegetables, and possibly cause water pollution accompanied with soil water mobilization.

Development of a coupled wave-flow-vegetation interaction model

USGS Publications Warehouse

Beudin, Alexis; Kalra, Tarandeep S.; Ganju, Neil K.; Warner, John C.

2017-01-01

Emergent and submerged vegetation can significantly affect coastal hydrodynamics. However, most deterministic numerical models do not take into account their influence on currents, waves, and turbulence. In this paper, we describe the implementation of a wave-flow-vegetation module into a Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system that includes a flow model (ROMS) and a wave model (SWAN), and illustrate various interacting processes using an idealized shallow basin application. The flow model has been modified to include plant posture-dependent three-dimensional drag, in-canopy wave-induced streaming, and production of turbulent kinetic energy and enstrophy to parameterize vertical mixing. The coupling framework has been updated to exchange vegetation-related variables between the flow model and the wave model to account for wave energy dissipation due to vegetation. This study i) demonstrates the validity of the plant posture-dependent drag parameterization against field measurements, ii) shows that the model is capable of reproducing the mean and turbulent flow field in the presence of vegetation as compared to various laboratory experiments, iii) provides insight into the flow-vegetation interaction through an analysis of the terms in the momentum balance, iv) describes the influence of a submerged vegetation patch on tidal currents and waves separately and combined, and v) proposes future directions for research and development.

Review on urban vegetation and particle air pollution - Deposition and dispersion

NASA Astrophysics Data System (ADS)

Janhäll, Sara

2015-03-01

Urban vegetation affects air quality through influencing pollutant deposition and dispersion. Both processes are described by many existing models and experiments, on-site and in wind tunnels, focussing e.g. on urban street canyons and crossings or vegetation barriers adjacent to traffic sources. There is an urgent need for well-structured experimental data, including detailed empirical descriptions of parameters that are not the explicit focus of the study. This review revealed that design and choice of urban vegetation is crucial when using vegetation as an ecosystem service for air quality improvements. The reduced mixing in trafficked street canyons on adding large trees increases local air pollution levels, while low vegetation close to sources can improve air quality by increasing deposition. Filtration vegetation barriers have to be dense enough to offer large deposition surface area and porous enough to allow penetration, instead of deflection of the air stream above the barrier. The choice between tall or short and dense or sparse vegetation determines the effect on air pollution from different sources and different particle sizes.

National Park Service Vegetation Mapping Inventory Program: Appalachian National Scenic Trail vegetation mapping project

USGS Publications Warehouse

Hop, Kevin D.; Strassman, Andrew C.; Hall, Mark; Menard, Shannon; Largay, Ery; Sattler, Stephanie; Hoy, Erin E.; Ruhser, Janis; Hlavacek, Enrika; Dieck, Jennifer

2017-01-01

The National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program classifies, describes, and maps existing vegetation of national park units for the NPS Natural Resource Inventory and Monitoring (I&M) Program. The NPS VMI Program is managed by the NPS I&M Division and provides baseline vegetation information to the NPS Natural Resource I&M Program. The U.S. Geological Survey Upper Midwest Environmental Sciences Center, NatureServe, NPS Northeast Temperate Network, and NPS Appalachian National Scenic Trail (APPA) have completed vegetation classification and mapping of APPA for the NPS VMI Program.Mappers, ecologists, and botanists collaborated to affirm vegetation types within the U.S. National Vegetation Classification (USNVC) of APPA and to determine how best to map the vegetation types by using aerial imagery. Analyses of data from 1,618 vegetation plots were used to describe USNVC associations of APPA. Data from 289 verification sites were collected to test the field key to vegetation associations and the application of vegetation associations to a sample set of map polygons. Data from 269 validation sites were collected to assess vegetation mapping prior to submitting the vegetation map for accuracy assessment (AA). Data from 3,265 AA sites were collected, of which 3,204 were used to test accuracy of the vegetation map layer. The collective of these datasets affirmed 280 USNVC associations for the APPA vegetation mapping project.To map the vegetation and land cover of APPA, 169 map classes were developed. The 169 map classes consist of 150 that represent natural (including ruderal) vegetation types in the USNVC, 11 that represent cultural (agricultural and developed) vegetation types in the USNVC, 5 that represent natural landscapes with catastrophic disturbance or some other modification to natural vegetation preventing accurate classification in the USNVC, and 3 that represent nonvegetated water (non-USNVC). Features were interpreted from viewing 4

Control of disinfection by-products in canned vegetables caused by water used in their processing.

PubMed

Cardador, Maria Jose; Gallego, Mercedes

2017-01-01

Canned vegetables come into contact with sanitizers and/or treated water in industry during several steps (namely washing, sanitising, blanching and filling with sauces or brine solutions) and therefore they can contain disinfection by-products - DBPs). This study focused on the occurrence of trihalomethanes (THMs) and haloacetic acids (HAAs) in a wide variety of canned vegetables (75 samples). For each vegetable, the edible solid and liquid phases of the package were separated and analysed individually. DBPs can be present in both solid (up to eight species) and liquid (up to 11 species) phases, their levels being higher in liquid ones. Volatile THMs predominate in the edible solid phase (up to four species), while HAAs do so in the liquid phase (up to five species) according to their ionic and non-volatile nature. The lowest concentrations of DBPs were found in tomatoes because they were often preserved in their own juice, without water.

On modeling the organization of landscapes and vegetation patterns controlled by solar radiation

NASA Astrophysics Data System (ADS)

Istanbulluoglu, E.; Yetemen, O.

2014-12-01

Solar radiation is a critical driver of ecohydrologic processes and vegetation dynamics. Patterns of runoff generation and vegetation dictate landscape geomorphic response. Distinct patterns in the organization of soil moisture, vegetation type, and landscape morphology have been documented in close relation to aspect in a range of climates. Within catchments, from north to south facing slopes, studies have shown ecotone shifts from forest to shrub species, and steep diffusion-dominated landforms to fluvial landforms. Over the long term differential evolution of ecohydrology and geomorphology leads to observed asymmetric structure in the planform of channel network and valley morphology. In this talk we present examples of coupled modeling of ecohydrology and geomorphology driven by solar radiation. In a cellular automata model of vegetation dynamics we will first show how plants organize in north and south facing slopes and how biodiversity changes with elevation. When vegetation-erosion feedbacks are coupled emergent properties of the coupled system are observed in the modeled elevation and vegetation fields. Integrating processes at a range of temporal and spatial scales, coupled models of ecohydrologic and geomorphic dynamics enable examination of global change impacts on landscapes and ecosystems.

Will European agricultural policy for school fruit and vegetables improve public health? A review of school fruit and vegetable programmes.

PubMed

de Sa, Joia; Lock, Karen

2008-12-01

For the first time, public health, particularly obesity, is being seen as a driver of EU agricultural policy. In 2007, European Ministers of Agriculture were asked to back new proposals for school fruit and vegetable programmes as part of agricultural reforms. In 2008, the European Commission conducted an impact assessment to assess the potential impact of this new proposal on health, agricultural markets, social equality and regional cohesion. A systematic review of the effectiveness of interventions to promote fruit and/or vegetable consumption in children in schools, to inform the EC policy development process. School schemes are effective at increasing both intake and knowledge. Of the 30 studies included, 70% increased fruits and vegetables (FV) intake, with none decreasing intake. Twenty-three studies had follow-up periods >1 year and provide some evidence that FV schemes can have long-term impacts on consumption. Only one study led to both increased fruit and vegetable intake and reduction in weight. One study showed that school fruit and vegetable schemes can also help to reduce inequalities in diet. Effective school programmes have used a range of approaches and been organized in ways which vary nationally depending on differences in food supply chain and education systems. EU agriculture policy for school fruits and vegetables schemes should be an effective approach with both public health and agricultural benefits. Aiming to increase FV intake amongst a new generation of consumers, it will support a range of EU policies including obesity and health inequalities.

Experimental investigation into the impact of vegetation on fan morphology and flow

NASA Astrophysics Data System (ADS)

Clarke, Lucy; McLelland, Stuart; Coulthard, Tom

2013-04-01

Riparian vegetation can significantly influence the geomorphology of fluvial systems, affecting channel geometry and flow dynamics. However, there is still limited understanding of the role vegetation plays in the development of alluvial fans, despite the large number of vegetated fans located in temperate and humid climates. An understanding of the feedback loops between water flow, sediment dynamics and vegetation is key to understanding the geomorphological response of alluvial fans. But it is difficult to investigate these relationships in the natural world due to the complexity of the geomorphic and biological processes and timescales involved. To examine the effects of vegetation on channel form, flow dynamics and morphology during fan evolution, a series of experiments were conducted using the Total Environment Simulator at the Deep, an experimental facility operated by the University of Hull. The experiments followed a 'similarity of processes' approach and so were not scaled to a specific field prototype. Live vegetation (alfalfa) was used to simulate the influence of vegetation on the fan development. A range of experiments were conducted on fan plots 2x2m in size, the same initial conditions and constant water discharge and sediment feed rates were used, but the vegetation density and amount of geomorphic time (when the sediment and water were running and there was active fan development) between seeding / vegetation growth varied between runs. The fan morphology was recorded at regular intervals using a laser scanner (at 1mm resolution) and high resolution video recording and overhead photography was also used to gain near-continuous data quantifying fan topography, flow patterns, channel migration and avulsion frequency. Image analysis also monitored the spatial extent of vegetation establishment. The use of these techniques allowed collection of high resolution spatial and temporal data on fan development with minimal disruption to the experiments

Soil-geomorphic heterogeneity governs patchy vegetation dynamics at an arid ecotone.

PubMed

Bestelmeyer, Brandon T; Ward, Judy P; Havstad, Kris M

2006-04-01

Soil properties are well known to affect vegetation, but the role of soil heterogeneity in the patterning of vegetation dynamics is poorly documented. We asked whether the location of an ecotone separating grass-dominated and sparsely vegetated areas reflected only historical variation in degradation or was related to variation in inherent soil properties. We then asked whether changes in the cover and spatial organization of vegetated and bare patches assessed using repeat aerial photography reflected self-organizing dynamics unrelated to soil variation or the stable patterning of soil variation. We found that the present-day ecotone was related to a shift from more weakly to more strongly developed soils. Parts of the ecotone were stable over a 60-year period, but shifts between bare and vegetated states, as well as persistently vegetated and bare states, occurred largely in small (<40 m2) patches throughout the study area. The probability that patches were presently vegetated or bare, as well as the probability that vegetation persisted and/or established over the 60-year period, was negatively related to surface calcium carbonate and positively related to subsurface clay content. Thus, only a fraction of the landscape was susceptible to vegetation change, and the sparsely vegetated area probably featured a higher frequency of susceptible soil patches. Patch dynamics and self-organizing processes can be constrained by subtle (and often unrecognized) soil heterogeneity.

EVAPORATION OF FRUITS AND VEGETABLES

PubMed Central

Cruess, W. V.

1921-01-01

More and more the world is utilizing dried fruits and vegetables, the war having given impetus to the preparation of the latter. Here are plain statements of processes and values deduced from scientific institution investigations. Evaporation is in its infancy while sun drying is very ancient. Evaporated products are better looking but more costly. ImagesFigure 1Figure 2Figure 3 PMID:18010426

An enhanced TIMESAT algorithm for estimating vegetation phenology metrics from MODIS data

USGS Publications Warehouse

Tan, B.; Morisette, J.T.; Wolfe, R.E.; Gao, F.; Ederer, G.A.; Nightingale, J.; Pedelty, J.A.

2011-01-01

An enhanced TIMESAT algorithm was developed for retrieving vegetation phenology metrics from 250 m and 500 m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indexes (VI) over North America. MODIS VI data were pre-processed using snow-cover and land surface temperature data, and temporally smoothed with the enhanced TIMESAT algorithm. An objective third derivative test was applied to define key phenology dates and retrieve a set of phenology metrics. This algorithm has been applied to two MODIS VIs: Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). In this paper, we describe the algorithm and use EVI as an example to compare three sets of TIMESAT algorithm/MODIS VI combinations: a) original TIMESAT algorithm with original MODIS VI, b) original TIMESAT algorithm with pre-processed MODIS VI, and c) enhanced TIMESAT and pre-processed MODIS VI. All retrievals were compared with ground phenology observations, some made available through the National Phenology Network. Our results show that for MODIS data in middle to high latitude regions, snow and land surface temperature information is critical in retrieving phenology metrics from satellite observations. The results also show that the enhanced TIMESAT algorithm can better accommodate growing season start and end dates that vary significantly from year to year. The TIMESAT algorithm improvements contribute to more spatial coverage and more accurate retrievals of the phenology metrics. Among three sets of TIMESAT/MODIS VI combinations, the start of the growing season metric predicted by the enhanced TIMESAT algorithm using pre-processed MODIS VIs has the best associations with ground observed vegetation greenup dates. ?? 2010 IEEE.

An Enhanced TIMESAT Algorithm for Estimating Vegetation Phenology Metrics from MODIS Data

NASA Technical Reports Server (NTRS)

Tan, Bin; Morisette, Jeffrey T.; Wolfe, Robert E.; Gao, Feng; Ederer, Gregory A.; Nightingale, Joanne; Pedelty, Jeffrey A.

2012-01-01

An enhanced TIMESAT algorithm was developed for retrieving vegetation phenology metrics from 250 m and 500 m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indexes (VI) over North America. MODIS VI data were pre-processed using snow-cover and land surface temperature data, and temporally smoothed with the enhanced TIMESAT algorithm. An objective third derivative test was applied to define key phenology dates and retrieve a set of phenology metrics. This algorithm has been applied to two MODIS VIs: Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). In this paper, we describe the algorithm and use EVI as an example to compare three sets of TIMESAT algorithm/MODIS VI combinations: a) original TIMESAT algorithm with original MODIS VI, b) original TIMESAT algorithm with pre-processed MODIS VI, and c) enhanced TIMESAT and pre-processed MODIS VI. All retrievals were compared with ground phenology observations, some made available through the National Phenology Network. Our results show that for MODIS data in middle to high latitude regions, snow and land surface temperature information is critical in retrieving phenology metrics from satellite observations. The results also show that the enhanced TIMESAT algorithm can better accommodate growing season start and end dates that vary significantly from year to year. The TIMESAT algorithm improvements contribute to more spatial coverage and more accurate retrievals of the phenology metrics. Among three sets of TIMESAT/MODIS VI combinations, the start of the growing season metric predicted by the enhanced TIMESAT algorithm using pre-processed MODIS VIs has the best associations with ground observed vegetation greenup dates.

Characterization of Seasonally Dependent Emergent Vegetation Variables for Coastal Impact Models

NASA Astrophysics Data System (ADS)

Stellern, C.; Grossman, E.; Linneman, S. R.; Fuller, R.

2015-12-01

Emergent wetland vegetation has been shown to mitigate coastal inundation and erosion hazards by reducing wave energy through friction (Shepard et al., 2011), although its use in coastal protection planning is limited because predictive models require improved vegetation data. We isolated biophysical characteristics (biomass, stem density, rigidity, etc.) of plants using horizontal digital photographs (Side-On Photos) in conjunction with remote sensing and physical surveys. We studied the dominant salt-marsh species/assemblages in Port Susan Bay of Washington State, a vulnerable estuary that has experienced up to 1 kilometer of marsh retreat since the mid-1960s. We measured plant height, stem diameter, stem density (area available for flow) from fall to early spring (August 2014 through April 2015) using Side-On Photography and digital image processing techniques. Metrics from Side-On Photography were highly correlated to physical lab measurements. Vegetation rigidity was measured in-situ with a handheld digital scale with respect to measurement height and bending angle. Plant elasticity showed a strong correlation to stem diameter in two dominant bulrush species. We employed remote sensing supervised classifications techniques (Maximum-Likelihood and Decision Tree Classifiers) to hyperspectral imagery to map the spatial extent of vegetation assemblages with an overall accuracy of 86.7%. Combining these methods enabled us to extrapolate and validate vegetation characteristics across the study area and to estimate species-specific friction coefficients for input to cross-shore wave models. On-going studies include sensitivity analyses of wave models to seasonally-dependent vegetation parameters in the nearshore and ultimately wave impacts along the coast. By accounting for site-specific and spatiotemporal variability in vegetation data, we inform scientific understanding of the interactions of vegetation, waves, and sediment processes.

CO₂ processing and hydration of fruit and vegetable tissues by clathrate hydrate formation.

PubMed

Takeya, Satoshi; Nakano, Kohei; Thammawong, Manasikan; Umeda, Hiroki; Yoneyama, Akio; Takeda, Tohoru; Hyodo, Kazuyuki; Matsuo, Seiji

2016-08-15

CO2 hydrate can be used to preserve fresh fruits and vegetables, and its application could contribute to the processing of carbonated frozen food. We investigated water transformation in the frozen tissue of fresh grape samples upon CO2 treatment at 2-3 MPa and 3°C for up to 46 h. Frozen fresh bean, radish, eggplant and cucumber samples were also investigated for comparison. X-ray diffraction indicated that after undergoing CO2 treatment for several hours, structure I CO2 hydrate formed within the grape tissue. Phase-contrast X-ray imaging using the diffraction-enhanced imaging technique revealed the presence of CO2 hydrate within the intercellular spaces of these tissues. The carbonated produce became effervescent because of the dissociation of CO2 hydrate through the intercellular space, especially above the melting point of ice. In addition, suppressed metabolic activity resulting from CO2 hydrate formation, which inhibits water and nutrient transport through intercellular space, can be expected. Copyright © 2016 Elsevier Ltd. All rights reserved.

Groundwater controls on vegetation composition and patterning in mountain meadows

NASA Astrophysics Data System (ADS)

Lowry, Christopher S.; Loheide, Steven P., II; Moore, Courtney E.; Lundquist, Jessica D.

2011-10-01

Mountain meadows are groundwater-dependent ecosystems that are hot spots of biodiversity and productivity. In the Sierra Nevada mountains of California, these ecosystems rely on shallow groundwater to support their vegetation communities during the dry summer growing season in the region's Mediterranean montane climate. Vegetation composition in this environment is influenced by both (1) oxygen stress that occurs when portions of the root zone are saturated and anaerobic conditions limit root respiration and (2) water stress that occurs when the water table drops and the root zone becomes water limited. A spatially distributed watershed model that explicitly accounts for snowmelt processes was linked to a fine-resolution groundwater flow model of Tuolumne Meadows in Yosemite National Park, California, to simulate water table dynamics. This linked hydrologic model was calibrated to observations from a well observation network for 2006-2009. A vegetation survey was also conducted at the site in which the three dominant species were identified at more than 200 plots distributed across the meadow. Nonparametric multiplicative regression was performed to create and select the best models for predicting vegetation dominance on the basis of the simulated hydrologic regime. The hydrologic niches of three vegetation types representing wet, moist, and dry meadow vegetation communities were found to be best described using both (1) a sum exceedance value calculated as the integral of water table position above a depth threshold of oxygen stress and (2) a sum exceedance value calculated as the integral of water table position below a depth threshold of water stress. This linked hydrologic and vegetative modeling framework advances our ability to predict the propagation of human-induced climatic and land use or land cover changes through the hydrologic system to the ecosystem. The hydroecologic functioning of meadows provides an example of the extent to which cascading

Riparian Vegetation Encroachment Ratios in rivers below large Dams

NASA Astrophysics Data System (ADS)

Garcia de Jalón, Diego; Martínez-Fernández, Vanesa; González del Tánago, Marta

2017-04-01

with different air photographs resolution. Results show a generalized natural vegetation encroachment process. Two exceptions were found associated with farming (Jarama 3) and poplar plantation (Alberche 1) that occupied riparian soils.. Annual encroachment ratios, range from 1 to 55 Ha/km, with a mean value of 12 Ha per km of river length. Higher values are found in the lowest reaches, which are far from the dam (5 cases), and also in the years following the beginning of dam operation. However, other reaches showed a delay of several years in the encroaching process, likely associated to scarcity or absence of initial woody vegetation at the time when dam started working.

Health-promoting components of fruits and vegetables in the diet.

PubMed

Liu, Rui Hai

2013-05-01

Regular consumption of fruits, vegetables, whole grains, and other plant foods has been negatively correlated with the risk of the development of chronic diseases. There is a huge gap between the average consumption of fruits and vegetables in Americans and the amount recommended by the 2010 Dietary Guidelines for Americans. The key is to encourage consumers to increase the total amount to 9 to 13 servings of fruits and vegetables in all forms available. Fresh, processed fruits and vegetables including frozen and canned, cooked, 100% fruit juices and 100% vegetable juices, as well as dry fruits are all considered as servings of fruits and vegetables per day. A wide variety of fruits, vegetables, whole grains, and other plant foods provide a range of nutrients and different bioactive compounds including phytochemicals, vitamins, minerals, and fibers. Potatoes serve as one of the low-fat foods with unique nutrients and phytochemical profiles, particularly rich in vitamin C, vitamin B-6, potassium, manganese, and dietary fibers. Potatoes provide 25% of vegetable phenolics in the American diet, the largest contributors among the 27 vegetables commonly consumed in the United States, including flavonoids (quercetin and kaempferol), phenolic acids (chlorogenic acid and caffeic acid), and carotenoids (lutein and zeaxanthin). More and more evidence suggests that the health benefits of fruits, vegetables, whole grains, and other plant foods are attributed to the synergy or interactions of bioactive compounds and other nutrients in whole foods. Therefore, consumers should obtain their nutrients, antioxidants, bioactive compounds, and phytochemicals from a balanced diet with a wide variety of fruits, vegetables, whole grains, and other plant foods for optimal nutrition, health, and well-being, not from dietary supplements.

Listeria monocytogenes - Danger for health safety vegetable production.

PubMed

Kljujev, Igor; Raicevic, Vera; Jovicic-Petrovic, Jelena; Vujovic, Bojana; Mirkovic, Milica; Rothballer, Michael

2018-04-22

The microbiologically contaminated vegetables represent a risk for consumers, especially vegetables without thermal processing. It is known that human pathogen bacteria, such as Listeria monocytogenes, could exist on fresh vegetables. The fresh vegetables could become Listeria-contaminated if they come in touch with contaminated soil, manure, irrigation water. The aim of this work was to investigate the presence of Listeria spp. and L. monocytogenes in different kind of vegetables grown in field and greenhouse condition as well as surface and endophytic colonization plant roots of different vegetables species by L. monocytogenes in laboratory conditions. The detection of Listeria spp. and L. monocytogenes in vegetable samples was done using ISO and PCR methods. The investigation of colonization vegetable roots and detection Listeria-cells inside plant root tissue was done using Fluorescence in situ hybridization (FISH) method in combination with confocal laser scanning microscopy (CLSM). The results showed that 25.58% vegetable samples were positive for Listeria spp. and only one sample (carrot) was positive for L. monocytogenes out of 43 samples in total collected from field and greenhouse. The strain L. monocytogenes EGD-E surface and endophytic colonized carrot root in highest degree while strain L. monocytogenes SV4B was the most represented at leafy vegetable plants, such at lettuce (1.68 × 10 6  cells/mm 3 absolutely dry root) and spinach (1.39 × 10 6  cells/mm 3 absolutely dry root) root surface. The cells of L. monocytogenes SV4B were visible as single cells in interior tissue of plant roots (celery and sweet corn roots) as well as in the interior of the plant root cell at sweet corn root. The cells of L. monocytogenes EGD-E bind to the surface of the plant root and they were less commonly found out on root hair. In the inner layers of the root, those bacterial cells were inhabited intercellular spaces mainly as single cells very close to the

Maintaining antioxidant potential of fresh fruits and vegetables after harvest.

PubMed

Villa-Rodriguez, Jose A; Palafox-Carlos, H; Yahia, Elhadi M; Ayala-Zavala, J Fernando; Gonzalez-Aguilar, Gustavo A

2015-01-01

The consumption of fruits and vegetables has increased in the past few years, not only because of their attractive sensorial properties, but also for their nutritional and health benefits. Antioxidants are compounds found in fresh fruits and vegetables, and evidence of their role in the prevention of degenerative diseases is continuously emerging. However, the antioxidants in some fruits and vegetables can be lost during handling after harvest, even during minimal processing and storage. In this sense, postharvest treatments are needed to preserve the quality and antioxidant potential of fresh produce. Postharvest treatments and technologic strategies (including ultraviolet light, controlled and modified atmospheres, heat treatments, and application of natural compounds, such as edible coatings, active packaging, microencapsulation, and nanoemulsion) have shown positive and promising results to maintain fruit and vegetable antioxidant potential. The purpose of this review is to analyze and propose the application of postharvest strategies to maintain, or even improve, the antioxidant status of fruits and vegetables, thus offering options to maximize health benefits to consumers.

Presence of Trihalomethanes in ready-to-eat vegetables disinfected with chlorine.

PubMed

Coroneo, Valentina; Carraro, Valentina; Marras, Barbara; Marrucci, Alessandro; Succa, Sara; Meloni, Barbara; Pinna, Antonella; Angioni, Alberto; Sanna, Adriana; Schintu, Marco

2017-12-01

Trihalomethanes (THMs) - CHCl 3 , CHCl 2 Br, CHClBr 2 and CHBr 3 - are drinking water disinfection by-products (DBPs). These compounds can also be absorbed by different types of foods, including ready-to-eat (RTE) fresh vegetables. The potential absorption of THMs during washing of RTE vegetables could pose a potential risk to consumers' health. The concentration of THMs in the water used in the manufacturing process of these products shall not exceed the limit of 100 or 80 µgL -1 according to European Union (EU) and United States legislation, respectively. By contrast, there is little information about the presence of such compounds in the final product. This study evaluated the concentration of THMs in different types of RTE vegetables (carrots, iceberg lettuce, lettuce, mixed salad, parsley, parsley and garlic, rocket salad, valerian) after washing with chlorinated water. In the 115 samples analysed, the average value of total THMs was equal to 76.7 ng g -1 . Chloroform was the THM present in the largest percentage in all the RTE vegetables. These results show that the process of washing RTE vegetables should be optimised in order to reduce the risk for consumers associated with the presence of DBPs.

Ecogeomorphology of Sand Dunes Shaped by Vegetation

NASA Astrophysics Data System (ADS)

Tsoar, H.

2014-12-01

Two dune types associated with vegetation are known: Parabolic and Vegetated Linear Dunes (VLDs), the latters are the dominant dune type in the world deserts. Parabolic dunes are formed in humid, sub-humid and semi-arid environments (rather than arid) where vegetation is nearby. VLDs are known today in semiarid and arid lands where the average yearly rainfall is ≥100 mm, enough to support sparse cover of vegetation. These two dune types are formed by unidirectional winds although they demonstrate a different form and have a distinct dynamics. Conceptual and mathematical models of dunes mobility and stability, based on three control parameters: wind power (DP), average annual precipitation (p), and the human impact parameter (μ) show that where human impact is negligible the effect of wind power (DP) on vegetative cover is substantial. The average yearly rainfall of 60-80 mm is the threshold of annual average rainfall for vegetation growth on dune sand. The model is shown to follow a hysteresis path, which explains the bistability of active and stabilized dunes under the same climatic conditions with respect to wind power. We have discerned formation of parabolic dunes from barchans and transverse dunes in the coastal plain of Israel where a decrease in human activity during the second half of the 20th century caused establishment of vegetation on the crest of the dunes, a process that changed the dynamics of these barchans and transverse dunes and led to a change in the shape of the windward slope from convex to concave. These dunes gradually became parabolic. It seems that VLDs in Australia or the Kalahari have always been vegetated to some degree, though the shrubs were sparser in colder periods when the aeolian erosion was sizeable. Those ancient conditions are characterized by higher wind power and lower rainfall that can reduce, but not completely destroy, the vegetation cover, leading to the formation of lee (shadow) dunes behind each shrub. Formation of

Microbioligical Hazard Contamination in Fermented Vegetables Sold in Local Markets in Cambodia.

PubMed

Chrun, Rithy; Hosotani, Yukie; Kawasaki, Susumu; Inatsu, Yasuhiro

2017-01-01

　Fermented vegetables are common part of Cambodian diet. The food safety status for these foods has not been investigated. This study was conducted to evaluate the microbiological hazards that contaminated fermented vegetables. A total of 68 samples of fermented vegetables were purchased randomly from five wet markets in Phnom Penh. The conventional culture methods for microbiological analysis were used. Coliform bacteria (Escherichia coli, Cronobactersakazakii, and Enterobacter spp.), opportunistic non-Entrobacteriaceae, Enterococcus spp., Staphylococcus spp., and Listeria spp. were found in these fermented foods. The highest contamination rate of Enterococcus spp. was 34% of total fermented vegetable samples, followed by Bacillus spp. coliform bacteria and E. coli (31%, 24% and 10%, respectively). The potential foodborne pathogen, C. sakazakii, was identified in one sample. Fermented mixed vegetables showed higher contamination rate of coliform bacteria (50%) than fermented single-type vegetables (13%). The results showed that fermented vegetables sold in wet market are poor in hygiene. The stage in the processing chain where contamination occurred should be identified and basic sanitary practice should be enforced to improve the food safety of fermented vegetables in Cambodia.

Evaluation of mercury methylation and methylmercury demethylation rates in vegetated and non-vegetated saltmarsh sediments from two Portuguese estuaries.

PubMed

Cesário, Rute; Hintelmann, Holger; Mendes, Ricardo; Eckey, Kevin; Dimock, Brian; Araújo, Beatriz; Mota, Ana Maria; Canário, João

2017-07-01

Neurotoxic methylmercury (MMHg) is formed from inorganic divalent mercury (Hg 2+ ). However, it is poorly understood to what extent different mercury (Hg) pools contribute to existent MMHg levels. In this study, ambient concentrations of total Hg (THg) and MMHg as well as rates of methylation and demethylation were measured simultaneously in sediments with and without salt-marsh plant vegetation, which were collected in Guadiana and Tagus estuaries, Portugal. Concurrent processes of Hg methylation and MMHg demethylation were directly monitored and compared by spiking sediments cores with stable isotope tracers of 199 Hg 2+ and CH 3 201 Hg + followed by gas chromatographic separation and isotope-specific detection using inductively coupled plasma mass spectrometry. Compared to the Guadiana estuary, where concentrations were comparatively low, THg and MMHg levels varied between vegetated and non-vegetated sediments collected at the Rosário site (ROS) of the Tagus estuary. Methylation (K M ) and demethylation rates (K D ) were also different between estuaries being dependent on the presence of vegetation. In addition, the type of macrophyte species influenced K M and K D values. In fact, the highest K M value was found in Sarcocornia fruticosa vegetated sediments at the Castro Marim site in Guadiana (CM, 0.160 day -1 ) and the lowest K M was observed in non-vegetated sediments at the Alcochete site in Tagus (ALC, 0.009 day -1 ). K D varied by a factor of three among sites with highest rates of demethylation observed in non-vegetated sediments in Guadiana (12 ± 1.3 day -1 , corresponding to a half-life of 1.4 ± 0.2 h). This study clearly shows that the presence of vegetation in sediments favors the formation of MMHg. Moreover, this effect might be site specific and further studies are needed to confirm the findings reported here. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of Refining Craft for Vegetable Insulating Oil

NASA Astrophysics Data System (ADS)

Zhou, Zhu-Jun; Hu, Ting; Cheng, Lin; Tian, Kai; Wang, Xuan; Yang, Jun; Kong, Hai-Yang; Fang, Fu-Xin; Qian, Hang; Fu, Guang-Pan

2016-05-01

Vegetable insulating oil because of its environmental friendliness are considered as ideal material instead of mineral oil used for the insulation and the cooling of the transformer. The main steps of traditional refining process included alkali refining, bleaching and distillation. This kind of refining process used in small doses of insulating oil refining can get satisfactory effect, but can't be applied to the large capacity reaction kettle. This paper using rapeseed oil as crude oil, and the refining process has been optimized for large capacity reaction kettle. The optimized refining process increases the acid degumming process. The alkali compound adds the sodium silicate composition in the alkali refining process, and the ratio of each component is optimized. Add the amount of activated clay and activated carbon according to 10:1 proportion in the de-colorization process, which can effectively reduce the oil acid value and dielectric loss. Using vacuum pumping gas instead of distillation process can further reduce the acid value. Compared some part of the performance parameters of refined oil products with mineral insulating oil, the dielectric loss of vegetable insulating oil is still high and some measures are needed to take to further optimize in the future.

Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem

NASA Astrophysics Data System (ADS)

Biber, P.; Seifert, S.; Zaplata, M. K.; Schaaf, W.; Pretzsch, H.; Fischer, A.

2013-12-01

We investigated surface and vegetation dynamics in the artificial initial ecosystem "Chicken Creek" (Lusatia, Germany) in the years 2006-2011 across a wide spectrum of empirical data. We scrutinized three overarching hypotheses concerning (1) the relations between initial geomorphological and substrate characteristics with surface structure and terrain properties, (2) the effects of the latter on the occurrence of grouped plant species, and (3) vegetation density effects on terrain surface change. Our data comprise and conflate annual vegetation monitoring results, biennial terrestrial laser scans (starting in 2008), annual groundwater levels, and initially measured soil characteristics. The empirical evidence mostly confirms the hypotheses, revealing statistically significant relations for several goal variables: (1) the surface structure properties, local rill density, local relief energy and terrain surface height change; (2) the cover of different plant groups (annual, herbaceous, grass-like, woody, Fabaceae), and local vegetation height; and (3) terrain surface height change showed significant time-dependent relations with a variable that proxies local plant biomass. Additionally, period specific effects (like a calendar-year optimum effect for the occurrence of Fabaceae) were proven. Further and beyond the hypotheses, our findings on the spatiotemporal dynamics during the system's early development grasp processes which generally mark the transition from a geo-hydro-system towards a bio-geo-hydro system (weakening geomorphology effects on substrate surface dynamics, while vegetation effects intensify with time), where pure geomorphology or substrate feedbacks are changing into vegetation-substrate feedback processes.

Automatically Generated Vegetation Density Maps with LiDAR Survey for Orienteering Purpose

NASA Astrophysics Data System (ADS)

Petrovič, Dušan

2018-05-01

The focus of our research was to automatically generate the most adequate vegetation density maps for orienteering purpose. Application Karttapullatuin was used for automated generation of vegetation density maps, which requires LiDAR data to process an automatically generated map. A part of the orienteering map in the area of Kazlje-Tomaj was used to compare the graphical display of vegetation density. With different settings of parameters in the Karttapullautin application we changed the way how vegetation density of automatically generated map was presented, and tried to match it as much as possible with the orienteering map of Kazlje-Tomaj. Comparing more created maps of vegetation density the most suitable parameter settings to automatically generate maps on other areas were proposed, too.

Development of freeze dried vegetables

NASA Technical Reports Server (NTRS)

Larson, R. W.

1970-01-01

The development of freeze dried vegetables to be used in the Apollo food system is discussed. After the initial selection and screening of vegetables, several types of freeze dried vegetables were prepared in small batches. From these small batches, two vegetables were judged satisfactory for further testing and evaluation. These vegetables, mashed potatoes and asparagus, were subjected to storage at 100 deg plus or minus 5 F. for two weeks and then taste tested. The vegetables were also tested to determine if they complied with the microbiological requirements for Apollo food. The space food prototype production guide for the vegetables is submitted.

Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery

DOE PAGES

Richardson, Andrew D.; Hufkens, Koen; Milliman, Tom; ...

2018-03-13

Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is also highly sensitive to climate change and variability. Here we present a series of datasets, together consisting of almost 750 years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength, automated digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 min) imagery,more » we derived time series characterizing vegetation colour, including "canopy greenness", processed to 1- and 3-day intervals. For ecosystems with one or more annual cycles of vegetation activity, we provide estimates, with uncertainties, for the start of the "greenness rising" and end of the "greenness falling" stages. Lastly, the database can be used for phenological model validation and development, evaluation of satellite remote sensing data products, benchmarking earth system models, and studies of climate change impacts on terrestrial ecosystems.« less

Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery

PubMed Central

Richardson, Andrew D.; Hufkens, Koen; Milliman, Tom; Aubrecht, Donald M.; Chen, Min; Gray, Josh M.; Johnston, Miriam R.; Keenan, Trevor F.; Klosterman, Stephen T.; Kosmala, Margaret; Melaas, Eli K.; Friedl, Mark A.; Frolking, Steve

2018-01-01

Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is also highly sensitive to climate change and variability. Here we present a series of datasets, together consisting of almost 750 years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength, automated digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 min) imagery, we derived time series characterizing vegetation colour, including “canopy greenness”, processed to 1- and 3-day intervals. For ecosystems with one or more annual cycles of vegetation activity, we provide estimates, with uncertainties, for the start of the “greenness rising” and end of the “greenness falling” stages. The database can be used for phenological model validation and development, evaluation of satellite remote sensing data products, benchmarking earth system models, and studies of climate change impacts on terrestrial ecosystems. PMID:29533393

Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, Andrew D.; Hufkens, Koen; Milliman, Tom

Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is also highly sensitive to climate change and variability. Here we present a series of datasets, together consisting of almost 750 years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength, automated digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 min) imagery,more » we derived time series characterizing vegetation colour, including "canopy greenness", processed to 1- and 3-day intervals. For ecosystems with one or more annual cycles of vegetation activity, we provide estimates, with uncertainties, for the start of the "greenness rising" and end of the "greenness falling" stages. Lastly, the database can be used for phenological model validation and development, evaluation of satellite remote sensing data products, benchmarking earth system models, and studies of climate change impacts on terrestrial ecosystems.« less

Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery

NASA Astrophysics Data System (ADS)

Richardson, Andrew D.; Hufkens, Koen; Milliman, Tom; Aubrecht, Donald M.; Chen, Min; Gray, Josh M.; Johnston, Miriam R.; Keenan, Trevor F.; Klosterman, Stephen T.; Kosmala, Margaret; Melaas, Eli K.; Friedl, Mark A.; Frolking, Steve

2018-03-01

Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is also highly sensitive to climate change and variability. Here we present a series of datasets, together consisting of almost 750 years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength, automated digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 min) imagery, we derived time series characterizing vegetation colour, including “canopy greenness”, processed to 1- and 3-day intervals. For ecosystems with one or more annual cycles of vegetation activity, we provide estimates, with uncertainties, for the start of the “greenness rising” and end of the “greenness falling” stages. The database can be used for phenological model validation and development, evaluation of satellite remote sensing data products, benchmarking earth system models, and studies of climate change impacts on terrestrial ecosystems.

Impacts of Seed Dispersal on Future Vegetation Structure under Changing Climates

NASA Astrophysics Data System (ADS)

Lee, E.; Schlosser, C. A.; Gao, X.; Prinn, R. G.

2011-12-01

As the impacts between land cover change, future climates and ecosystems are expected to be substantial, there are growing needs for improving the capability of simulating the global vegetation structure and landscape as realistically as possible. Current DGVMs assume ubiquitous availability of seeds and do not consider any seed dispersal mechanisms in plant migration process, which may influence the assessment of impacts to the ecosystem that rely on the vegetation structure changes (i.e., change in albedo, runoff, and terrestrial carbon sequestration capacity). This study incorporates time-varying wind-driven seed dispersal (i.e., the SEED configuration) as a dynamic constraint to the migration process of natural vegetation in the Community Land Model (CLM)-DGVM. The SEED configuration is validated using a satellite-derived tree cover dataset. Then the configuration is applied to project future vegetation structures and their implications for carbon fluxes, albedo, and hydrology under two climate mitigation scenarios (No-policy vs. 450ppm CO2 stabilization) for the 21st century. Our results show that regional changes of vegetation structure under changing climates are expected to be significant. For example, Alaska and Siberia are expected to experience substantial shifts of forestry structure, characterized by expansion of needle-leaf boreal forest and shrinkage of C3 grass Arctic. A suggested vulnerability assessment shows that vegetation structures in Alaska, Greenland, Central America, southern South America, East Africa and East Asia are susceptible to changing climates, regardless of the two climate mitigation scenarios. Regions such as Greenland, Tibet, South Asia and Northern Australia, however, may substantially alleviate their risks of rapid change in vegetation structure, given a robust greenhouse gas stabilization target. Proliferation of boreal forests in the high latitudes is expected to amplify the warming trend (i.e., a positive feedback to

Vegetables, but not pickled vegetables, are negatively associated with the risk of breast cancer.

PubMed

Yu, Hyejin; Hwang, Ji-Yun; Ro, Jungsil; Kim, Jeongseon; Chang, Namsoo

2010-01-01

This study investigated the association between pickled vegetable consumption and the risk of breast cancer using a validated food frequency questionnaire. A total of 358 patients with breast cancer who were matched to 360 healthy controls by age (using a 5-yr age distribution) were recruited from the National Cancer Center in South Korea. After adjusting for nondietary risk factors, total vegetable intake was inversely associated with risk of breast cancer. However, unlike nonpickled vegetables, pickled vegetable intake and its proportion relative to total vegetables were positively associated with the risk of breast cancer, and this association was more profound and consistent when pickled vegetable intake was considered as a proportion relative to total vegetables (odds ratio [OR] = 6.24, 95% confidence interval [CI] = 3.55-10.97; P for trend <0.001 for highest vs. lowest quartiles of intake) than as the absolute consumed amount (OR = 2.47, 95% CI = 1.45-4.21; P for trend = 0.015 for highest vs. lowest quartiles of intake). These results suggest that not only the amount of total vegetable intake but also the amounts of different types of vegetable (i.e., pickled or nonpickled) and their proportions relative to total vegetables are significantly associated with the risk of breast cancer.

The vegetation outlook (VegOut): a new method for predicting vegetation seasonal greenness

USGS Publications Warehouse

Tadesse, T.; Wardlow, B.; Hayes, M.; Svoboda, M.; Brown, J.

2010-01-01

The vegetation outlook (VegOut) is a geospatial tool for predicting general vegetation condition patterns across large areas. VegOut predicts a standardized seasonal greenness (SSG) measure, which represents a general indicator of relative vegetation health. VegOut predicts SSG values at multiple time steps (two to six weeks into the future) based on the analysis of "historical patterns" (i.e., patterns at each 1 km grid cell and time of the year) of satellite, climate, and oceanic data over an 18-year period (1989 to 2006). The model underlying VegOut capitalizes on historical climate-vegetation interactions and ocean-climate teleconnections (such as El Niño and the Southern Oscillation, ENSO) expressed over the 18-year data record and also considers several environmental characteristics (e.g., land use/cover type and soils) that influence vegetation's response to weather conditions to produce 1 km maps that depict future general vegetation conditions. VegOut provides regionallevel vegetation monitoring capabilities with local-scale information (e.g., county to sub-county level) that can complement more traditional remote sensing-based approaches that monitor "current" vegetation conditions. In this paper, the VegOut approach is discussed and a case study over the central United States for selected periods of the 2008 growing season is presented to demonstrate the potential of this new tool for assessing and predicting vegetation conditions.

FLUVIAL DISTURBANCE AND WETLAND VEGETATION DEVELOPMENT, UPPER MAIN STEM, WILLAMETTE RIVER, OREGON, USA

EPA Science Inventory

Hydrogeomorphic processes drive vegetation establishment, and promote development of diverse wetland and riparian types associated with lotic ecosystems. The main objective of this study was to estimate the rate and pattern of vegetation development on bars tracked since 1936, a...

A vegetation mapping strategy for conifer forests by combining airborne LiDAR data and aerial imagery

Treesearch

Yanjun Su; Qinghua Guo; Danny L. Fry; Brandon M. Collins; Maggi Kelly; Jacob P. Flanagan; John J. Battles

2016-01-01

Abstract. Accurate vegetation mapping is critical for natural resources management, ecological analysis, and hydrological modeling, among other tasks. Remotely sensed multispectral and hyperspectral imageries have proved to be valuable inputs to the vegetation mapping process, but they can provide only limited vegetation structure...

On the sources of vegetation activity variation, and their relation with water balance in Mexico

Treesearch

F. Mora; L.R. Iverson

1998-01-01

Natural landscape surface processes are largely controlled by the relationship between climate and vegetation. Water balance integrates the effects of climate on patterns of vegetation distribution and productivity, and for that season, functional relationships can be established using water balance variables as predictors of vegetation response. In this study, we...

Managing vegetation in surface-flow wastewater-treatment wetlands for optimal treatment performance

USGS Publications Warehouse

Thullen, J.S.; Sartoris, J.J.; Nelson, S.M.

2005-01-01

Constructed wetlands that mimic natural marshes have been used as low-cost alternatives to conventional secondary or tertiary wastewater treatment in the U.S. for at least 30 years. However, the general level of understanding of internal treatment processes and their relation to vegetation and habitat quality has not grown in proportion to the popularity of these systems. We have studied internal processes in surface-flow constructed wastewater-treatment wetlands throughout the southwestern U.S. since 1990. At any given time, the water quality, hydraulics, water temperature, soil chemistry, available oxygen, microbial communities, macroinvertebrates, and vegetation each greatly affect the treatment capabilities of the wetland. Inside the wetland, each of these components plays a functional role and the treatment outcome depends upon how the various components interact. Vegetation plays a uniquely important role in water treatment due to the large number of functions it supports, particularly with regard to nitrogen transformations. However, it has been our experience that vegetation management is critical for achieving and sustaining optimal treatment function. Effective water treatment function and good wildlife quality within a surface-flow constructed wetland depend upon the health and sustainability of the vegetation. We suggest that an effective tool to manage and sustain healthy vegetation is the use of hummocks, which are shallow emergent plant beds within the wetland, positioned perpendicular to the water flow path and surrounded by water sufficiently deep to limit further emergent vegetation expansion. In this paper, we describe the use of a hummock configuration, in conjunction with seasonal water level fluctuations, to manage the vegetation and maintain the treatment function of wastewater-treatment wetlands on a sustainable basis.

Information for forest process models: a review of NRS-FIA vegetation measurements

Treesearch

Charles D. Canham; William H. McWilliams

2012-01-01

The Forest and Analysis Program of the Northern Research Station (NRS-FIA) has re-designed Phase 3 measurements and intensified the sample intensity following a study to balance costs, utility, and sample size. The sampling scheme consists of estimating canopy-cover percent for six vegetation growth habits on 24-foot-radius subplots in four height classes and as an...

Evaluating the impact of a wide range of vegetation densities on river channel pattern

NASA Astrophysics Data System (ADS)

Pattison, Ian; Roucou, Ron

2016-04-01

Braided rivers are very dynamic systems which have complex controls over their planform and flow dynamics. Vegetation is one variable which influences channel geometry and pattern, through its effect on local flow hydraulics and the process continuum of sediment erosion-transport-deposition. Furthermore, where in the braided floodplain stable vegetation develops depends on the temporal sequencing of the river discharge i.e. floods. Understanding the effect of vegetation in these highly dynamic systems has multiple consequences for human activity and floodplain management. This paper focusses on the specific role of vegetation density in controlling braided river form and processes. Previous research in this field has been contradictory; with Gran and Paola (2001) finding that increasing vegetation density decreased the number of active channels. In contrast, Coulthard (2005] observed that as vegetation become denser there was an increase in the number of channels. This was hypothesized to be caused by flow separation around vegetation and the development of bars immediately downstream of the plant. This paper reports the results from a set of experiments in a 4m by 1m flume, where discharge, slope and sediment size were kept constant. Artificial grass was used to represent vegetation with a density ranging from 50 plants/m2 to 400 plants/m2. Digital photographs, using a GoPro camera with a fish eye lens, were taken from ~1m above the flume at an interval of 30 seconds during the 3 hour experiment. The experiments showed that as the vegetation density increased from 50 to 150 plants/m2, the number of channel bars developing doubled from 12 to 24. At vegetation densities greater than 150 plants/m2 there was a decline in the number of bars created to a minimum of 8 bars for a density of 400 plants/m2. We attribute these patterns to the effect that the vegetation has on flow hydraulics, sediment transport processes and the spatial patterns of erosion and deposition. We

Access to Fresh Fruits and Vegetables in School Lunches: A Policy Analysis.

PubMed

Schultz, Celeste; Thorlton, Janet

2018-01-01

Consumption of fresh fruits and vegetables helps to reduce childhood obesity and improves academic achievement and attendance. However, providing fresh fruits and vegetables is challenging for some schools due to cost, administrative burden, and concern for food waste. To address these challenges, the Fruit and Vegetable Access for Children Act proposes to allow federally funded programs to substitute fresh fruits and vegetables with canned, frozen, or pureed versions. In this policy analysis, we propose options for providing fresh fruits and vegetables to children enrolled in the National School Lunch Program. We recommend that school nurses actively facilitate the process of obtaining fresh fruits and vegetables by being appointed members of Team Nutrition giving them authority to collaborate with local famers, entrepreneurs, and land-grant universities in Farm to School Programs. This strategy empowers school nurses in promoting healthy eating habits, reducing obesity, and improving academic performance and school attendance.

[Assessment of the validity and reliability of the processes of change scale based on the transtheoretical model of vegetable consumption behavior in Japanese male workers].

PubMed

Kushida, Osamu; Murayama, Nobuko

2012-12-01

A core construct of the Transtheoretical model is that the processes and stages of change are strongly related to observable behavioral changes. We created the Processes of Change Scale of vegetable consumption behavior and examined the validity and reliability of this scale. In September 2009, a self-administered questionnaire was administered to male Japanese employees, aged 20-59 years, working at 20 worksites in Niigata City in Japan. The stages of change (precontempration, contemplation, preparation, action, and maintenance stage) were measured using 2 items that assessed participants' current implementation of the target behavior (eating 5 or more servings of vegetables per day) and their readiness to change their habits. The Processes of Change Scale of vegetable consumption behavior comprised 10 items assessing 5 cognitive processes (consciousness raising, emotional arousal, environmental reevaluation, self-reevaluation, and social liberation) and 5 behavioral processes (commitment, rewards, helping relationships, countering, and environment control). Each item was selected from an existing scale. Decisional balance (pros [2 items] and cons [2 items]), and self-efficacy (3 items) were also assessed, because these constructs were considered to be relevant to the processes of change. The internal consistency reliability of the scale was examined using Cronbach's alpha. Its construct validity was examined using a factor analysis of the processes of change, decisional balance, and self-efficacy variables, while its criterion-related validity was determined by assessing the association between the scale scores and the stages of change. The data of 527 (out of 600) participants (mean age, 41.1 years) were analyzed. Results indicated that the Processes of Change Scale had sufficient internal consistency reliability (Cronbach's alpha: cognitive processes=0.722, behavioral processes=0.803). The processes of change were divided into 2 factors: "consciousness raising

Slow recovery in desert perennial vegetation following prolonged human disturbance

USGS Publications Warehouse

Guo, Q.

2004-01-01

Questions: How long may it take for desert perennial vegetation to recover from prolonged human disturbance and how do different plant community variables (i.e. diversity, density and cover) change during the recovery process? Location: Sonoran Desert, Arizona, USA. Methods: Since protection from grazing from 1907 onwards, plant diversity, density and cover of perennial species were monitored intermittently on ten 10 m x 10 m permanent plots on Tumamoc Hill, Tucson, Arizona, USA. Results: The study shows an exceptionally slow recovery of perennial vegetation from prolonged heavy grazing and other human impacts. Since protection, overall species richness and habitat heterogeneity at the study site continued to increase until the 1960s when diversity, density and cover had been stabilized. During the same period, overall plant density and cover also increased. Species turnover increased gradually with time but no significant relation between any of the three community variables and precipitation or Palmer Drought Severity Index (PDSI) was detected. Conclusions: It took more than 50 yr for the perennial vegetation to recover from prolonged human disturbance. The increases in plant species richness, density, and cover of the perennial vegetation were mostly due to the increase of herbaceous species, especially palatable species. The lack of a clear relationship between environment (e.g. precipitation) and community variables suggests that site history and plant life history must be taken into account in examining the nature of vegetation recovery processes after disturbance.

Global vegetation-fire pattern under different land use and climate conditions

NASA Astrophysics Data System (ADS)

Thonicke, K.; Poulter, B.; Heyder, U.; Gumpenberger, M.; Cramer, W.

2008-12-01

Fire is a process of global significance in the Earth System influencing vegetation dynamics, biogeochemical cycling and biophysical feedbacks. Naturally ignited wildfires have long history in the Earth System. Humans have been using fire to shape the landscape for their purposes for many millenia, sometimes influencing the status of the vegetation remarkably as for example in Mediterranean-type ecosystems. Processes and drivers describing fire danger, ignitions, fire spread and effects are relatively well-known for many fire-prone ecosystems. Modeling these has a long tradition in fire-affected regions to predict fire risk and behavior for fire-fighting purposes. On the other hand, the global vegetation community realized the importance of disturbances to be recognized in their global vegetation models with fire being globally most important and so-far best studied. First attempts to simulate fire globally considered a minimal set of drivers, whereas recent developments attempt to consider each fire process separately. The process-based fire model SPITFIRE (SPread and InTensity of FIRE) simulates these processes embedded in the LPJ DGVM. Uncertainties still arise from missing measurements for some parameters in less-studied fire regimes, or from broad PFT classifications which subsume different fire-ecological adaptations and tolerances. Some earth observation data sets as well as fire emission models help to evaluate seasonality and spatial distribution of simulated fire ignitions, area burnt and fire emissions within SPITFIRE. Deforestation fires are a major source of carbon released to the atmosphere in the tropics; in the Amazon basin it is the second-largest contributor to Brazils GHG emissions. How ongoing deforestation affects fire regimes, forest stability and biogeochemical cycling in the Amazon basin under present climate conditions will be presented. Relative importance of fire vs. climate and land use change is analyzed. Emissions resulting from

Sediment and Vegetation Controls on Delta Channel Networks

NASA Astrophysics Data System (ADS)

Lauzon, R.; Murray, A. B.; Piliouras, A.; Kim, W.

2016-12-01

Numerous factors control the patterns of distributary channels formed on a delta, including water and sediment discharge, grain size, sea level rise rates, and vegetation type. In turn, these channel networks influence the shape and evolution of a delta, including what types of plant and animal life - such as humans - it can support. Previous fluvial modeling and flume experiments, outside of the delta context, have addressed how interactions between sediment and vegetation, through their influence on lateral transport of sediment, determine what type of channel networks develops. Similar interactions likely also shape delta flow patterns. Vegetation introduces cohesion, tending to reduce channel migration rates and strengthen existing channel banks, reinforcing existing channels and resulting in localized, relatively stable flow patterns. On the other hand, sediment transport processes can result in lateral migration and frequent switching of active channels, resulting in flow resembling that of a braided stream. While previous studies of deltas have indirectly explored the effects of vegetation through the introduction of cohesive sediment, we directly incorporate key effects of vegetation on flow and sediment transport into the delta-building model DeltaRCM to explore how these effects influence delta channel network formation. Model development is informed by laboratory flume experiments at UT Austin. Here we present initial results of experiments exploring the effects of sea level rise rate, sediment grain size, vegetation type, and vegetation growth rate on delta channel network morphology. These results support the hypothesis that the ability for lateral transport of sediment to occur plays a key role in determining the evolution of delta channel networks and delta morphology.

Riparian vegetation controls on channels formed in non-cohesive sediment

NASA Astrophysics Data System (ADS)

Gran, K.; Tal, M.; Paola, C.

2002-05-01

, vegetation is reseeded following repeat high flow events, simulating the natural process of vegetation encroachment on the floodplain and channel.

ISSUES IN DIGITAL IMAGE PROCESSING OF AERIAL PHOTOGRAPHY FOR MAPPING SUBMERSED AQUATIC VEGETATION

EPA Science Inventory

The paper discusses the numerous issues that needed to be addressed when developing a methodology for mapping Submersed Aquatic Vegetation (SAV) from digital aerial photography. Specifically, we discuss 1) choice of film; 2) consideration of tide and weather constraints; 3) in-s...

Estimating vegetation dryness to optimize fire risk assessment with spot vegetation satellite data in savanna ecosystems

NASA Astrophysics Data System (ADS)

Verbesselt, J.; Somers, B.; Lhermitte, S.; van Aardt, J.; Jonckheere, I.; Coppin, P.

2005-10-01

The lack of information on vegetation dryness prior to the use of fire as a management tool often leads to a significant deterioration of the savanna ecosystem. This paper therefore evaluated the capacity of SPOT VEGETATION time-series to monitor the vegetation dryness (i.e., vegetation moisture content per vegetation amount) in order to optimize fire risk assessment in the savanna ecosystem of Kruger National Park in South Africa. The integrated Relative Vegetation Index approach (iRVI) to quantify the amount of herbaceous biomass at the end of the rain season and the Accumulated Relative Normalized Difference vegetation index decrement (ARND) related to vegetation moisture content were selected. The iRVI and ARND related to vegetation amount and moisture content, respectively, were combined in order to monitor vegetation dryness and optimize fire risk assessment in the savanna ecosystems. In situ fire activity data was used to evaluate the significance of the iRVI and ARND to monitor vegetation dryness for fire risk assessment. Results from the binary logistic regression analysis confirmed that the assessment of fire risk was optimized by integration of both the vegetation quantity (iRVI) and vegetation moisture content (ARND) as statistically significant explanatory variables. Consequently, the integrated use of both iRVI and ARND to monitor vegetation dryness provides a more suitable tool for fire management and suppression compared to other traditional satellite-based fire risk assessment methods, only related to vegetation moisture content.

Uprooting of flexible riparian vegetation: field and laboratory observations

NASA Astrophysics Data System (ADS)

Solari, L.; Calvani, G.; Francalanci, S.

2017-12-01

Vegetation is a key element in fluvial systems, controlling river corridor form and dynamics. Plants actively interact with fluvial processes; their aboveground biomass can affect the flow field and sediment transport and therefore river morphological evolution, whereas their belowground biomass modifies the hydraulic and mechanical properties of the substrate, and consequently the moisture regime and erodibility of the soil (Gurnell, 2014; Solari et al., 2015). Vegetation biomass can either increase over time or can die through the mechanism of uprooting. Despite its important implications in river morphodynamics, vegetation uprooting due to sediment transport during flood events have been poorly investigated (Edmaier et al., 2011). Most of previous research focused on the mechanism of root breakage and on measuring the vegetation resistance to uprooting in the vertical direction (Bywater-Reyes et al., 2015, among others). In this work, we focus on the uprooting of flexible juvenile seedlings vegetation due to flow and to bed erosion. First, we derive a physics-based model for the prediction of vegetation uprooting for given root geometry, soil strength characteristics, flow bed shear stress and bed erosion. The model is then tested in a laboratory flume using two different species of vegetation: Avena sativa and Salix purpurea. Various experiments were run considering increasing flow discharges and a quasi- parallel bed erosion. The vegetation model is then applied to a sediment bar in the Ombrone Pistoiese river where we observed the removal of Salix Purpurea during the flood of November 2016. We implemented a 2D hydraulic model to reconstruct the pattern of bed shear stresses on the bar and we compared the prediction of the vegetation model with the field surveys of Salix purpurea before and after the flood. Results suggest that juvenile seedlings can be easily removed by the flow provided sediment transport takes place.

Employing lidar to detail vegetation canopy architecture for prediction of aeolian transport

USGS Publications Warehouse

Sankey, Joel B.; Law, Darin J.; Breshears, David D.; Munson, Seth M.; Webb, Robert H.

2013-01-01

The diverse and fundamental effects that aeolian processes have on the biosphere and geosphere are commonly generated by horizontal sediment transport at the land surface. However, predicting horizontal sediment transport depends on vegetation architecture, which is difficult to quantify in a rapid but accurate manner. We demonstrate an approach to measure vegetation canopy architecture at high resolution using lidar along a gradient of dryland sites ranging from 2% to 73% woody plant canopy cover. Lidar-derived canopy height, distance (gaps) between vegetation elements (e.g., trunks, limbs, leaves), and the distribution of gaps scaled by vegetation height were correlated with canopy cover and highlight potentially improved horizontal dust flux estimation than with cover alone. Employing lidar to estimate detailed vegetation canopy architecture offers promise for improved predictions of horizontal sediment transport across heterogeneous plant assemblages.

Experimental trampling of vegetation. I. Relationship between trampling intensity and vegetation response

Treesearch

David N. Cole

1995-01-01

1. Experimental trampling was conducted in 18 vegetation types in five separate mountain regions in the United States. Each type was trampled 0-500 times. Response to trampling was assessed by determining vegetation cover 2 weeks after trampling and 1 year after trampling.2. Response varied significantly with trampling intensity and vegetation type. Trampling...

Vegetation diversity

Treesearch

Beth Schulz

2011-01-01

Vegetation is the source of primary production and a fundamental determinant of habitat and wildfire fuel profile characterization. As such, changes in vegetation can have cascading effects through an ecosystem. While individual species can be important indicators of a site’s potential productivity, economic value, and wildlife forage and shelter, changes in the...

Experiments in water-macrophyte systems to uncover the dynamics of pesticide mitigation processes in vegetated surface waters/streams.

PubMed

Stang, Christoph; Bakanov, Nikita; Schulz, Ralf

2016-01-01

Knowledge on the dynamics and the durability of the processes governing the mitigation of pesticide loads by aquatic vegetation in vegetated streams, which are characterized by dynamic discharge regimes and short chemical residence times, is scarce. In a static long-term experiment (48 h), the dissipation of five pesticides from the aqueous phase followed a biphasic pattern in the presence of aquatic macrophytes. A dynamic concentration decrease driven by sorption to the macrophytes ranged from 8.3 to 60.4% for isoproturon and bifenox, respectively, within the first 2 h of exposure. While the aqueous concentrations of imidacloprid, isoproturon, and tebufenozide remained constant thereafter, the continuous but decelerated concentration decrease of difenoconazole and bifenox in the water-macrophyte systems used here was assumed to be attributed to macrophyte-induced degradation processes. In addition, a semi-static short-term experiment was conducted, where macrophytes were transferred to uncontaminated medium after 2 h of exposure to simulate a transient pesticide peak. In the first part of the experiment, adsorption to macrophytes resulted in partitioning coefficients (logK D_Adsorp) ranging from 0.2 for imidacloprid to 2.2 for bifenox. One hour after the macrophytes were transferred to the uncontaminated medium, desorption of the compounds from the macrophytes resulted in a new phase equilibrium and K D_Desorp values of 1.46 for difenoconazole and 1.95 for bifenox were determined. A correlation analysis revealed the best match between the compound affinity to adsorb to macrophytes (expressed as K D_Adsorp) and their soil organic carbon-water partitioning coefficient (K OC) compared to their octanol-water partitioning coefficient (K OW) or a mathematically derived partitioning coefficient.

National Park Service Vegetation Mapping Inventory Program: Natchez Trace Parkway vegetation mapping project report

USGS Publications Warehouse

Hop, Kevin D.; Strassman, Andrew C.; Nordman, Carl; Pyne, Milo; White, Rickie; Jakusz, Joseph; Hoy, Erin E.; Dieck, Jennifer

2016-01-01

The National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program is an effort to classify, describe, and map existing vegetation of national park units for the NPS Natural Resource Inventory and Monitoring (I&M) Program. The NPS VMI Program is managed by the NPS I&M Division and provides baseline vegetation information to the NPS Natural Resource I&M Program. The U.S. Geological Survey Upper Midwest Environmental Sciences Center, NatureServe, NPS Gulf Coast Network, and NPS Natchez Trace Parkway (NATR; also referred to as Parkway) have completed vegetation classification and mapping of NATR for the NPS VMI Program.Mappers, ecologists, and botanists collaborated to affirm vegetation types within the U.S. National Vegetation Classification (USNVC) of NATR and to determine how best to map them by using aerial imagery. Analyses of data from 589 vegetation plots had been used to describe an initial 99 USNVC associations in the Parkway; this classification work was completed prior to beginning this NATR vegetation mapping project. Data were collected during this project from another eight quick plots to support new vegetation types not previously identified at the Parkway. Data from 120 verification sites were collected to test the field key to vegetation associations and the application of vegetation associations to a sample set of map polygons. Furthermore, data from 900 accuracy assessment (AA) sites were collected (of which 894 were used to test accuracy of the vegetation map layer). The collective of all these datasets resulted in affirming 122 USNVC associations at NATR.To map the vegetation and open water of NATR, 63 map classes were developed. including the following: 54 map classes represent natural (including ruderal) vegetation types in the USNVC, 5 map classes represent cultural (agricultural and developed) vegetation types in the USNVC, 3 map classes represent nonvegetation open-water bodies (non-USNVC), and 1 map class represents landscapes that

Spatial hydrological flow processes, water quality, sediment and vegetation community distributions in a natural floodplain fen - implication for the Flood Pulse Concept

NASA Astrophysics Data System (ADS)

Keizer, Floris; Schot, Paul; Wassen, Martin; Kardel, Ignacy; Okruszko, Tomasz

2017-04-01

We studied spatial patterns in inundation water quality, sediment and vegetation distribution in a floodplain fen in Poland to map interacting peatland hydrological processes. Using PCA and K-means cluster analysis, we identified four water types, related to river water inundation, discharge of clean and polluted groundwater, and precipitation and snowmelt dilution. Spatially, these hydrochemical water types are related to known water sources in the floodplain and occupy distinctive zones. River water is found along the river, clean and polluted groundwater at the valley margins and groundwater diluted with precipitation and snowmelt water in the central part of the floodplain. This implies that, despite the floodplain being completely inundated, nutrient input from river flooding occurs only in a relatively narrow zone next to the river. Our findings question the relevance of the edge of inundation, as presented in the Flood Pulse Concept, as delineating the zone of input and turnover of nutrients. Secondly, we studied rich-fen and freshwater vegetation community distributions in relation to the presented inundation water quality types. We successfully determined inundation water quality preference for 14 out of 17 studied rich-fen and freshwater communities in the floodplain. Spatial patterns in preference show vegetation with attributed river water preference to occur close to the river channel, with increasing distance to the river followed by communities with no preference, diluted groundwater preference in the central part, and clean and polluted groundwater preference at the valley margins. In inundation water, nutrients are known to be transported mainly as attached to sediment, besides in dissolved state. This means that in the zone where sediment deposition occurs, nutrient input can be a relevant contribution to the nutrient input of the floodplain. We found a significant decrease in sediment-attached nutrient deposition with distance from the river

Reanalysis of global terrestrial vegetation trends from MODIS products: Browning or greening?

Treesearch

Yulong Zhang; Conghe Song; Lawrence E. Band; Ge Sun; Junxiang Li

2017-01-01

Accurately monitoring global vegetation dynamics with modern remote sensing is critical for understanding the functions and processes of the biosphere and its interactions with the planetary climate. The MODerate resolution Imaging Spectroradiometer (MODIS) vegetation index (VI) product has been a primary data source for this purpose. To date, theMODIS teamhad released...

Drought-induced vegetation shifts in terrestrial ecosystems: The key role of regeneration dynamics

NASA Astrophysics Data System (ADS)

Martínez-Vilalta, Jordi; Lloret, Francisco

2016-09-01

Ongoing climate change is modifying climatic conditions worldwide, with a trend towards drier conditions in most regions. Vegetation will respond to these changes, eventually adjusting to the new climate. It is unclear, however, how close different ecosystems are to climate-related tipping points and, thus, how dramatic these vegetation changes will be in the short- to mid-term, given the existence of strong stabilizing processes. Here, we review the published evidence for recent drought-induced vegetation shifts worldwide, addressing the following questions: (i) what are the necessary conditions for vegetation shifts to occur? (ii) How much evidence of drought-induced vegetation shifts do we have at present and where are they occurring? (iii) What are the main processes that favor/oppose the occurrence of shifts at different ecological scales? (iv) What are the complications in detecting and attributing drought-induced vegetation shifts? (v) What ecological factors can interact with drought to promote shifts or stability? We propose a demographic framework to classify the likely outcome of instances of drought-induced mortality, based upon the survival of adults of potential replacement species and the regeneration of both formerly dominant affected species and potential replacement species. Out of 35 selected case studies only eight were clearly consistent with the occurrence of a vegetation shift (species or biome shift), whereas three corresponded to self-replacements in which the affected, formerly dominant species was able to regenerate after suffering drought-induced mortality. The other 24 cases were classified as uncertain, either due to lack of information or, more commonly, because the initially affected and potential replacement species all showed similar levels of regeneration after the mortality event. Overall, potential vegetation transitions were consistent with more drought-resistant species replacing less resistant ones. However, almost half (44

Monitoring tropical vegetation succession with LANDSAT data

NASA Technical Reports Server (NTRS)

Robinson, V. B. (Principal Investigator)

1983-01-01

The shadowing problem, which is endemic to the use of LANDSAT in tropical areas, and the ability to model changes over space and through time are problems to be addressed when monitoring tropical vegetation succession. Application of a trend surface analysis model to major land cover classes in a mountainous region of the Phillipines shows that the spatial modeling of radiance values can provide a useful approach to tropical rain forest succession monitoring. Results indicate shadowing effects may be due primarily to local variations in the spectral responses. These variations can be compensated for through the decomposition of the spatial variation in both elevation and MSS data. Using the model to estimate both elevation and spectral terrain surface as a posteriori inputs in the classification process leads to improved classification accuracy for vegetation of cover of this type. Spatial patterns depicted by the MSS data reflect the measurement of responses to spatial processes acting at several scales.

Formation of banded vegetation patterns resulted from interactions between sediment deposition and vegetation growth.

PubMed

Huang, Tousheng; Zhang, Huayong; Dai, Liming; Cong, Xuebing; Ma, Shengnan

2018-03-01

This research investigates the formation of banded vegetation patterns on hillslopes affected by interactions between sediment deposition and vegetation growth. The following two perspectives in the formation of these patterns are taken into consideration: (a) increased sediment deposition from plant interception, and (b) reduced plant biomass caused by sediment accumulation. A spatial model is proposed to describe how the interactions between sediment deposition and vegetation growth promote self-organization of banded vegetation patterns. Based on theoretical and numerical analyses of the proposed spatial model, vegetation bands can result from a Turing instability mechanism. The banded vegetation patterns obtained in this research resemble patterns reported in the literature. Moreover, measured by sediment dynamics, the variation of hillslope landform can be described. The model predicts how treads on hillslopes evolve with the banded patterns. Thus, we provide a quantitative interpretation for coevolution of vegetation patterns and landforms under effects of sediment redistribution. Copyright © 2018. Published by Elsevier Masson SAS.

Deciphering the Costs of Reproduction in Mango – Vegetative Growth Matters

PubMed Central

Capelli, Mathilde; Lauri, Pierre-Éric; Normand, Frédéric

2016-01-01

Irregular fruit production across successive years is a major issue that limits the profitability of most temperate and tropical fruit crops. It is particularly affected by the reciprocal relationships between vegetative and reproductive growth. The concept of the costs of reproduction is defined in terms of losses in the potential future reproductive success caused by current investment in reproduction. This concept, developed in ecology and evolutionary biology, could provide a methodological framework to analyze irregular bearing in fruit crops, especially in relation to the spatial scale at which studies are done. The objective of this study was to investigate the direct effects of reproduction during a growing cycle on reproduction during the following growing cycle and the indirect effects through vegetative growth between these two reproductive events, for four mango cultivars and during two growing cycles. Two spatial scales were considered: the growth unit (GU) and the scaffold branch. Costs of reproduction were detected between two successive reproductive events and between reproduction and vegetative growth. These costs were scale-dependent, generally detected at the GU scale and infrequently at the scaffold branch scale, suggesting partial branch autonomy with respect to processes underlying the effects of reproduction on vegetative growth. In contrast, the relationships between vegetative growth and reproduction were positive at the GU scale and at the scaffold branch scale in most cases, suggesting branch autonomy for the processes, mainly local, underlying flowering and fruiting. The negative effect of reproduction on vegetative growth prevailed over the positive effect of vegetative growth on the subsequent reproduction. The costs of reproduction were also cultivar-dependent. Those revealed at the GU scale were related to the bearing behavior of each cultivar. Our results put forward the crucial role of vegetative growth occurring between two

Health-Promoting Components of Fruits and Vegetables in the Diet12

PubMed Central

Liu, Rui Hai

2013-01-01

Regular consumption of fruits, vegetables, whole grains, and other plant foods has been negatively correlated with the risk of the development of chronic diseases. There is a huge gap between the average consumption of fruits and vegetables in Americans and the amount recommended by the 2010 Dietary Guidelines for Americans. The key is to encourage consumers to increase the total amount to 9 to 13 servings of fruits and vegetables in all forms available. Fresh, processed fruits and vegetables including frozen and canned, cooked, 100% fruit juices and 100% vegetable juices, as well as dry fruits are all considered as servings of fruits and vegetables per day. A wide variety of fruits, vegetables, whole grains, and other plant foods provide a range of nutrients and different bioactive compounds including phytochemicals, vitamins, minerals, and fibers. Potatoes serve as one of the low-fat foods with unique nutrients and phytochemical profiles, particularly rich in vitamin C, vitamin B-6, potassium, manganese, and dietary fibers. Potatoes provide 25% of vegetable phenolics in the American diet, the largest contributors among the 27 vegetables commonly consumed in the United States, including flavonoids (quercetin and kaempferol), phenolic acids (chlorogenic acid and caffeic acid), and carotenoids (lutein and zeaxanthin). More and more evidence suggests that the health benefits of fruits, vegetables, whole grains, and other plant foods are attributed to the synergy or interactions of bioactive compounds and other nutrients in whole foods. Therefore, consumers should obtain their nutrients, antioxidants, bioactive compounds, and phytochemicals from a balanced diet with a wide variety of fruits, vegetables, whole grains, and other plant foods for optimal nutrition, health, and well-being, not from dietary supplements. PMID:23674808

Quantification of Listeria monocytogenes in minimally processed leafy vegetables using a combined method based on enrichment and 16S rRNA real-time PCR.

PubMed

Aparecida de Oliveira, Maria; Abeid Ribeiro, Eliana Guimarães; Morato Bergamini, Alzira Maria; Pereira De Martinis, Elaine Cristina

2010-02-01

Modern lifestyle markedly changed eating habits worldwide, with an increasing demand for ready-to-eat foods, such as minimally processed fruits and leafy greens. Packaging and storage conditions of those products may favor the growth of psychrotrophic bacteria, including the pathogen Listeria monocytogenes. In this work, minimally processed leafy vegetables samples (n = 162) from retail market from Ribeirão Preto, São Paulo, Brazil, were tested for the presence or absence of Listeria spp. by the immunoassay Listeria Rapid Test, Oxoid. Two L. monocytogenes positive and six artificially contaminated samples of minimally processed leafy vegetables were evaluated by the Most Probable Number (MPN) with detection by classical culture method and also culture method combined with real-time PCR (RTi-PCR) for 16S rRNA genes of L. monocytogenes. Positive MPN enrichment tubes were analyzed by RTi-PCR with primers specific for L. monocytogenes using the commercial preparation ABSOLUTE QPCR SYBR Green Mix (ABgene, UK). Real-time PCR assay presented good exclusivity and inclusivity results and no statistical significant difference was found in comparison with the conventional culture method (p < 0.05). Moreover, RTi-PCR was fast and easy to perform, with MPN results obtained in ca. 48 h for RTi-PCR in comparison to 7 days for conventional method.

Vegetation management with fire modifies peatland soil thermal regime.

PubMed

Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

2015-05-01

Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from <2 to 15 + years post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (<2-4 years) showed higher mean, maximum and range of soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15 + years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned <2 years previously showed significant statistical disturbances from model predictions, reaching +6.2 °C for daily mean temperatures and +19.6 °C for daily maxima. Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15 + years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime

Direct and terrestrial vegetation-mediated effects of environmental change on aquatic ecosystem processes

Treesearch

Becky A. Ball; John S. Kominoski; Heather E. Adams; Stuart E. Jones; Evan S. Kane; Terrance D. Loecke; Wendy M. Mahaney; Jason P. Martina; Chelse M. Prather; Todd M.P. Robinson; Christopher T. Solomon

2010-01-01

Global environmental changes have direct effects on aquatic ecosystems, as well as indirect effects through alterations of adjacent terrestrial ecosystem structure and functioning. For example, shifts in terrestrial vegetation communities resulting from global changes can affect the quantity and quality of water, organic matter, and nutrient inputs to aquatic...

Observing vegetation phenology through social media.

PubMed

Silva, Sam J; Barbieri, Lindsay K; Thomer, Andrea K

2018-01-01

The widespread use of social media has created a valuable but underused source of data for the environmental sciences. We demonstrate the potential for images posted to the website Twitter to capture variability in vegetation phenology across United States National Parks. We process a subset of images posted to Twitter within eight U.S. National Parks, with the aim of understanding the amount of green vegetation in each image. Analysis of the relative greenness of the images show statistically significant seasonal cycles across most National Parks at the 95% confidence level, consistent with springtime green-up and fall senescence. Additionally, these social media-derived greenness indices correlate with monthly mean satellite NDVI (r = 0.62), reinforcing the potential value these data could provide in constraining models and observing regions with limited high quality scientific monitoring.

Adult Intake of Minimally Processed Fruits and Vegetables: Associations with Cardiometabolic Disease Risk Factors.

PubMed

Cavallo, David N; Horino, Masako; McCarthy, William J

2016-09-01

The US Department of Agriculture launched ChooseMyPlate.gov nutrition recommendations designed to encourage increased fruit and vegetable intake, in part, as a strategy for improving weight control through the consumption of high-satiation foods. The purpose of this cross-sectional study was to assess the relationship between adults' reported daily intake of fruits and nonstarchy vegetables (ie, those thought to have the lowest energy density) expressed as a proportion of their total daily food intake and objectively measured cardiovascular and metabolic disease risk factors using data from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). Physical activity was included as a moderator variable. This study employed a cross-sectional examination of 2009-2010 NHANES data to assess how daily fruit and nonstarchy vegetable intake was associated with anthropometric measures and cardiometabolic blood chemistry markers. Adults free of cardiac or metabolic disease (n=1,197) participated in 24-hour dietary recalls; a variety of cardiometabolic biomarkers and anthropometric measures were also collected from participants. Among participants with complete data on all variables, the ratio of the combined cup-equivalents of fruit and nonstarchy vegetable intake to the total gram weight of all foods consumed daily (F/V ratio) served as the primary independent variable. Main dependent measures included fasting glucose, insulin, glycosylated hemoglobin, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, total cholesterol, waist circumference, and body mass index. Demographic and behavioral predictors of the F/V ratio and the association between the F/V ratio and cardiometabolic disease risk factors were examined using multivariate regression. Body mass index (β=-2.58; 95% CI -3.88 to -1.28), waist circumference (β=-6.33; 95% CI -9.81 to -2.84), and insulin (β=-0.21; 95% CI -0.37 to -0.05) were inversely

Adult intake of minimally processed fruits and vegetables: Associations with cardiometabolic disease risk factors

PubMed Central

Horino, Masako; McCarthy, William J.

2016-01-01

Background The U.S. Department of Agriculture launchedChooseMyPlate.gov nutrition recommendations designed to encourage increased fruit and vegetable intake in part as a strategy for improving weight control through the consumption of high satiation foods. Objective The purpose of this cross-sectional study was to assess the relationship between adults’ reported daily intake of fruits and non-starchy vegetables (i.e., those thought to have the lowest energy density) expressed as a proportion of their total daily food intake and objectively measured cardiovascular and metabolic disease risk factors using data from the 2009–2010 National Health and Examination Survey (NHANES). Physical activity was included as a moderator variable. Design This study employed a cross-sectional examination of 2009–2010 NHANES data to assess how daily fruit and non-starchy vegetable intake were associated with anthropometric measures and cardiometabolic blood chemistry markers. Participants/setting Adults free of cardiac or metabolic disease (N=1,197) participated in 24-hour dietary recalls; a variety of cardiometabolic biomarkers and anthropometric measures were also collected from participants. Main outcome measures Among participants with complete data on all variables, the ratio of the combined cup equivalents of fruit and non-starchy vegetable intake to the total gram weight of all foods consumed daily (FV ratio) served as the primary independent variable. Main dependent measures included: fasting glucose, insulin, glycosylated hemoglobin, HDL cholesterol, LDL cholesterol, triglycerides, total cholesterol, waist circumference, and body mass index. Statistical analyses performed Demographic and behavioral predictors of the FV ratio and the association between the FV ratio and cardiometabolic disease risk factors were examined using multivariate regression. Results BMI (β = −2.58, 95% CI [−3.88, −1.28]), waist circumference (β = −6.33, 95% CI [−9.81, −2.84]), and

Model-data integration to improve the LPJmL dynamic global vegetation model

NASA Astrophysics Data System (ADS)

Forkel, Matthias; Thonicke, Kirsten; Schaphoff, Sibyll; Thurner, Martin; von Bloh, Werner; Dorigo, Wouter; Carvalhais, Nuno

2017-04-01

Dynamic global vegetation models show large uncertainties regarding the development of the land carbon balance under future climate change conditions. This uncertainty is partly caused by differences in how vegetation carbon turnover is represented in global vegetation models. Model-data integration approaches might help to systematically assess and improve model performances and thus to potentially reduce the uncertainty in terrestrial vegetation responses under future climate change. Here we present several applications of model-data integration with the LPJmL (Lund-Potsdam-Jena managed Lands) dynamic global vegetation model to systematically improve the representation of processes or to estimate model parameters. In a first application, we used global satellite-derived datasets of FAPAR (fraction of absorbed photosynthetic activity), albedo and gross primary production to estimate phenology- and productivity-related model parameters using a genetic optimization algorithm. Thereby we identified major limitations of the phenology module and implemented an alternative empirical phenology model. The new phenology module and optimized model parameters resulted in a better performance of LPJmL in representing global spatial patterns of biomass, tree cover, and the temporal dynamic of atmospheric CO2. Therefore, we used in a second application additionally global datasets of biomass and land cover to estimate model parameters that control vegetation establishment and mortality. The results demonstrate the ability to improve simulations of vegetation dynamics but also highlight the need to improve the representation of mortality processes in dynamic global vegetation models. In a third application, we used multiple site-level observations of ecosystem carbon and water exchange, biomass and soil organic carbon to jointly estimate various model parameters that control ecosystem dynamics. This exercise demonstrates the strong role of individual data streams on the

Vegetation Patterns and Degradation Thresholds in the Mulga Landscapes of Australia

NASA Astrophysics Data System (ADS)

Azadi, Samira; Saco, Patricia; Moreno-de las Heras, Mariano; Willgoose, Garry

2017-04-01

Drylands are often characterised by a spatially heterogeneous vegetation cover forming mosaics of patches dense vegetation within bare soil. This 'patterned' or 'patchy' vegetation cover is sensitive to human pressures. Previous work suggests that within these landscapes there is a critical vegetation cover threshold below which the landscape functionality is lost. This threshold behaviour is tightly linked to the overland flow redistribution and an increase in hydrologic connectivity that induces loss of resources (i.e., leakiness). In fact, disturbances (such as wildfire, overgrazing or harvesting activities) can disrupt the spatial structure of vegetation, increase landscape hydrologic connectivity, trigger erosion and produce a substantial loss of water. All these effects affect ecosystem functionality. Here we present the results of exploring the impact of degradation processes induced by vegetation disturbances (mainly grazing) on ecosystem functionality and connectivity in semiarid landscapes with various types of vegetation patterns. The sites are carefully selected in Mulga landscapes bioregion (New South Wales, Queensland) and in sites of Northern Territory in Australia, which display similar vegetation characteristics but with different vegetation patterns and good quality rainfall information. The analysis of vegetation patterns is derived from high resolution remote sensing images (IKONOS, QuickBird, Pleiades). Using MODIS NDVI and local precipitation data, we compute rainfall use efficiency and precipitation marginal response in order to assess the ecosystem functionality. We use vegetation binary maps and digital elevation models to estimate mean Flowlength as an indicator of structural hydrologic connectivity. We compare the trends for several sites with varying vegetation patterns (i.e., banded versus spotted patterns). Our results show that disturbances increase hydrologic connectivity and suggest threshold behaviour that affects landscape

Where does the carbon go? A model–data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites

PubMed Central

De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Walker, Anthony P; Dietze, Michael C; Wang, Ying-Ping; Luo, Yiqi; Jain, Atul K; El-Masri, Bassil; Hickler, Thomas; Wårlind, David; Weng, Ensheng; Parton, William J; Thornton, Peter E; Wang, Shusen; Prentice, I Colin; Asao, Shinichi; Smith, Benjamin; McCarthy, Heather R; Iversen, Colleen M; Hanson, Paul J; Warren, Jeffrey M; Oren, Ram; Norby, Richard J

2014-01-01

Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets. PMID:24844873

Vegetables affect the expression of genes involved in anticarcinogenic processes in the colonic mucosa of C57BL/6 female mice.

PubMed

van Breda, Simone G J; van Agen, Ebienus; van Sanden, Suzy; Burzykowski, Tomasz; Kienhuis, Anne S; Kleinjans, Jos C S; van Delft, Joost H M

2005-08-01

There is abundant epidemiological evidence that vegetable consumption decreases colorectal cancer (CRC) risk. However, the molecular targets in the genome are mostly unknown. The present study investigated the effects of vegetable consumption on gene expression in the colon mucosa of female C57Bl/6 mice using cDNA microarray technology. Mice were fed one of 8 diets: a control diet containing no vegetables (diet 1); a diet containing 100 g/kg (diet 2, 10% dose), 200 g/kg (diet 3, 20% dose), or 400 g/kg (diet 4, 40% dose) of a vegetable mixture; or a diet containing 70 g/kg of cauliflower (diet 5, 7% dose), 73 g/kg of carrots (diet 6, 7.3% dose), 226 g/kg of peas (diet 7, 22.6% dose); or 31 g/kg of onions (diet 8, 3.1% dose). The vegetable mixture used in diets 2 to 4 consisted of the 4 individual vegetables used in diets 5 to 8: cauliflower (30% wet wt), carrots (30% wet wt), peas (30% wet wt), and onions (10% wet wt). To assess gene expression changes, colonic mucosal cells were collected after the mice were killed. Total RNA was isolated and microarray technology was used to measure the expression levels of 602 genes simultaneously. For 39 genes, significant dose-dependent effects were found, although in general the relations were not linear. For 15 genes, the altered expression could indeed explain reduced cancer risk at various stages of CRC development. Eleven genes were modulated by the vegetable mixture as well as by one or more of the individual vegetables. For 7 of the genes, the modulation by the mixture was due to the effect of a particular vegetable. These genes are of particular interest because they were consistently affected and could be involved in the prevention of CRC by vegetable consumption.

Quantifying Vegetation Biophysical Variables from Imaging Spectroscopy Data: A Review on Retrieval Methods

NASA Astrophysics Data System (ADS)

Verrelst, Jochem; Malenovský, Zbyněk; Van der Tol, Christiaan; Camps-Valls, Gustau; Gastellu-Etchegorry, Jean-Philippe; Lewis, Philip; North, Peter; Moreno, Jose

2018-06-01

An unprecedented spectroscopic data stream will soon become available with forthcoming Earth-observing satellite missions equipped with imaging spectroradiometers. This data stream will open up a vast array of opportunities to quantify a diversity of biochemical and structural vegetation properties. The processing requirements for such large data streams require reliable retrieval techniques enabling the spatiotemporally explicit quantification of biophysical variables. With the aim of preparing for this new era of Earth observation, this review summarizes the state-of-the-art retrieval methods that have been applied in experimental imaging spectroscopy studies inferring all kinds of vegetation biophysical variables. Identified retrieval methods are categorized into: (1) parametric regression, including vegetation indices, shape indices and spectral transformations; (2) nonparametric regression, including linear and nonlinear machine learning regression algorithms; (3) physically based, including inversion of radiative transfer models (RTMs) using numerical optimization and look-up table approaches; and (4) hybrid regression methods, which combine RTM simulations with machine learning regression methods. For each of these categories, an overview of widely applied methods with application to mapping vegetation properties is given. In view of processing imaging spectroscopy data, a critical aspect involves the challenge of dealing with spectral multicollinearity. The ability to provide robust estimates, retrieval uncertainties and acceptable retrieval processing speed are other important aspects in view of operational processing. Recommendations towards new-generation spectroscopy-based processing chains for operational production of biophysical variables are given.

Assessment of soil-vegetation cover condition in river basins applying remote sensing data

NASA Astrophysics Data System (ADS)

Mishchenko, Natalia; Petrosian, Janna; Shirkin, Leonid; Repkin, Roman

2017-04-01

Constant observation of vegetation and soil cover is one of the key issues of river basins ecologic monitoring. Lately remotely determining vegetation indices have been used for this purpose alongside with terrestrial data. It is necessary to consider that observation objects have been continuously changing and these changes are comprehensive and depend on temporal and dimensional parameters. Remote sensing data, embracing vast areas and reflecting various interrelations, allow excluding accidental and short-term changes though concentrating on the transformation of the observed river basin ecosystem environmental condition. The research objective is to assess spatial - temporal peculiarities and the dynamics of soil-vegetation condition of the Klyazma basin as whole and minor river basins within the area. Research objects are located in the centre of European Russia. Data used in our research include both statistic and published data, characterizing soil-vegetation cover of the area, space images («Landsat» ETM+ etc.) Research methods. 1. Dynamics analysis NDVI (Normalized difference vegetation index) 2. Remote data have been correlated to terrestrial measurement results of phytomass reserve, phytoproductivity, soil fertility characteristics, crop capacity (http://biodat.ru) 3. For the digital processing of space images software Erdas Imagine has been used, GIS analysis has been carried out applying Arc GIS. NDVI computation for each image pixel helped to map general condition of the Klyazma vegetation cover and to determine geographic ranges without vegetation or with depressed vegetation. For instance high vegetation index geographic range has been defined which corresponded to Vladimir Opolye characterized with the most fertile grey forest soil in the region. Comparative assessment of soil vegetation cover of minor river basins within the Klyazma basin, judging by the terrestrial data, revealed its better condition in the Koloksha basin which is also located

Resilience of riverbed vegetation to uprooting by flow

NASA Astrophysics Data System (ADS)

Perona, P.; Crouzy, B.

2018-03-01

Riverine ecosystem biodiversity is largely maintained by ecogeomorphic processes including vegetation renewal via uprooting and recovery times to flow disturbances. Plant roots thus heavily contribute to engineering resilience to perturbation of such ecosystems. We show that vegetation uprooting by flow occurs as a fatigue-like mechanism, which statistically requires a given exposure time to imposed riverbed flow erosion rates before the plant collapses. We formulate a physically based stochastic model for the actual plant rooting depth and the time-to-uprooting, which allows us to define plant resilience to uprooting for generic time-dependent flow erosion dynamics. This theory shows that plant resilience to uprooting depends on the time-to-uprooting and that root mechanical anchoring acts as a process memory stored within the plant-soil system. The model is validated against measured data of time-to-uprooting of Avena sativa seedlings with various root lengths under different flow conditions. This allows for assessing the natural variance of the uprooting-by-flow process and to compute the prediction entropy, which quantifies the relative importance of the deterministic and the random components affecting the process.

White vegetables: glycemia and satiety.

PubMed

Anderson, G Harvey; Soeandy, Chesarahmia Dojo; Smith, Christopher E

2013-05-01

The objective of this review is to discuss the effect of white vegetable consumption on glycemia, satiety, and food intake. White vegetables is a term used to refer to vegetables that are white or near white in color and include potatoes, cauliflowers, turnips, onions, parsnips, white corn, kohlrabi, and mushrooms (technically fungi but generally considered a vegetable). They vary greatly in their contribution to the energy and nutrient content of the diet and glycemia and satiety. As with other foods, the glycemic effect of many white vegetables has been measured. The results illustrate that interpretation of the semiquantitative comparative ratings of white vegetables as derived by the glycemic index must be context dependent. As illustrated by using the potato as an example, the glycemic index of white vegetables can be misleading if not interpreted in the context of the overall contribution that the white vegetable makes to the carbohydrate and nutrient composition of the diet and their functionality in satiety and metabolic control within usual meals. It is concluded that application of the glycemic index in isolation to judge the role of white vegetables in the diet and, specifically in the case of potato as consumed in ad libitum meals, has led to premature and possibly counterproductive dietary guidance.

Self-Replication of Localized Vegetation Patches in Scarce Environments

PubMed Central

Bordeu, Ignacio; Clerc, Marcel G.; Couteron, Piere; Lefever, René; Tlidi, Mustapha

2016-01-01

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora—and fauna within—or even make use of scarce resources soils. In this paper, we study a robust phenomena observed in semi-arid ecosystems, by which localized vegetation patches split in a process called self-replication. Localized patches of vegetation are visible in nature at various spatial scales. Even though they have been described in literature, their growth mechanisms remain largely unexplored. Here, we develop an innovative statistical analysis based on real field observations to show that patches may exhibit deformation and splitting. This growth mechanism is opposite to the desertification since it allows to repopulate territories devoid of vegetation. We investigate these aspects by characterizing quantitatively, with a simple mathematical model, a new class of instabilities that lead to the self-replication phenomenon observed. PMID:27650430

Self-Replication of Localized Vegetation Patches in Scarce Environments

NASA Astrophysics Data System (ADS)

Bordeu, Ignacio; Clerc, Marcel G.; Couteron, Piere; Lefever, René; Tlidi, Mustapha

2016-09-01

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora—and fauna within—or even make use of scarce resources soils. In this paper, we study a robust phenomena observed in semi-arid ecosystems, by which localized vegetation patches split in a process called self-replication. Localized patches of vegetation are visible in nature at various spatial scales. Even though they have been described in literature, their growth mechanisms remain largely unexplored. Here, we develop an innovative statistical analysis based on real field observations to show that patches may exhibit deformation and splitting. This growth mechanism is opposite to the desertification since it allows to repopulate territories devoid of vegetation. We investigate these aspects by characterizing quantitatively, with a simple mathematical model, a new class of instabilities that lead to the self-replication phenomenon observed.

Bacterial communities and enzymatic activities in the vegetation-activated sludge process (V-ASP) and related advantages by comparison with conventional constructed wetland.

PubMed

Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Zhao, Ke; Du, Changhang; Shao, Yunxian

2016-11-01

A new-developed vegetation-activated sludge process (V-ASP) was implemented for decentralized domestic wastewater treatment, and studied in lab-scale and full-scale. The main purpose of this work was the investigation of biomass activities and microbial communities in V-ASP by comparison with conventional constructed wetland (CW), to unveil the causations of its consistently higher pollutants removal efficiencies. Compared with CWs, V-ASP has greater vegetation nitrogen and phosphorus uptake rates, higher biomass and enzymatic activities, and more bacteria community diversity. The microbial community structure was comprehensively analyzed by using high-throughput sequencing. It was observed that Proteobacteria was dominated in both CWs and V-ASPs, while their subdivisions distribution was rather different. V-ASPs contained a higher nitrite-oxidizing bacteria (Nitrospira) abundances that resulted in a consistently better nitrogen removal efficiency. Hence, a long-term experiment of full-scale V-ASP displayed stably excellent capability in resistance of influent loading shocks and seasonal temperature effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Noise-induced transitions and shifts in a climate-vegetation feedback model.

PubMed

Alexandrov, Dmitri V; Bashkirtseva, Irina A; Ryashko, Lev B

2018-04-01

Motivated by the extremely important role of the Earth's vegetation dynamics in climate changes, we study the stochastic variability of a simple climate-vegetation system. In the case of deterministic dynamics, the system has one stable equilibrium and limit cycle or two stable equilibria corresponding to two opposite (cold and warm) climate-vegetation states. These states are divided by a separatrix going across a point of unstable equilibrium. Some possible stochastic scenarios caused by different externally induced natural and anthropogenic processes inherit properties of deterministic behaviour and drastically change the system dynamics. We demonstrate that the system transitions across its separatrix occur with increasing noise intensity. The climate-vegetation system therewith fluctuates, transits and localizes in the vicinity of its attractor. We show that this phenomenon occurs within some critical range of noise intensities. A noise-induced shift into the range of smaller global average temperatures corresponding to substantial oscillations of the Earth's vegetation cover is revealed. Our analysis demonstrates that the climate-vegetation interactions essentially contribute to climate dynamics and should be taken into account in more precise and complex models of climate variability.

On vegetation mapping in Alaska using LANDSAT imagery with primary concerns for method and purpose in satellite image-based vegetation and land-use mapping and the visual interpretation of imagery in photographic format

NASA Technical Reports Server (NTRS)

Anderson, J. H. (Principal Investigator)

1976-01-01

The author has identified the following significant results. A simulated color infrared LANDSAT image covering the western Seward Peninsula was used for identifying and mapping vegetation by direct visual examination. The 1:1,083,400 scale print used was prepared by a color additive process using positive transparencies from MSS bands 4, 5, and 7. Seven color classes were recognized. A vegetation map of 3200 sq km area just west of Fairbanks, Alaska was made. Five colors were recognized on the image and identified to vegetation types roughly equivalent to formations in the UNESCO classification: orange - broadleaf deciduous forest; gray - needleleaf evergreen forest; light violet - subarctic alpine tundra vegetation; violet - broadleaf deciduous shrub thicket; and dull violet - bog vegetation.

Different techniques of multispectral data analysis for vegetation fraction retrieval

NASA Astrophysics Data System (ADS)

Kancheva, Rumiana; Georgiev, Georgi

2012-07-01

Vegetation monitoring is one of the most important applications of remote sensing technologies. In respect to farmlands, the assessment of crop condition constitutes the basis of growth, development, and yield processes monitoring. Plant condition is defined by a set of biometric variables, such as density, height, biomass amount, leaf area index, and etc. The canopy cover fraction is closely related to these variables, and is state-indicative of the growth process. At the same time it is a defining factor of the soil-vegetation system spectral signatures. That is why spectral mixtures decomposition is a primary objective in remotely sensed data processing and interpretation, specifically in agricultural applications. The actual usefulness of the applied methods depends on their prediction reliability. The goal of this paper is to present and compare different techniques for quantitative endmember extraction from soil-crop patterns reflectance. These techniques include: linear spectral unmixing, two-dimensional spectra analysis, spectral ratio analysis (vegetation indices), spectral derivative analysis (red edge position), colorimetric analysis (tristimulus values sum, chromaticity coordinates and dominant wavelength). The objective is to reveal their potential, accuracy and robustness for plant fraction estimation from multispectral data. Regression relationships have been established between crop canopy cover and various spectral estimators.

Application of automated multispectral analysis to Delaware's coastal vegetation mapping

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Daiber, D.; Bartlett, D. S.; Crichton, O. W.; Fornes, A. O.

1973-01-01

There are no author-identified significant results in this report. Overlay maps of Delaware's wetlands have been prepared, showing the dominant species or group of species of vegetation present. Five such categories of vegetation were used indicating marshes dominated by: (1) salt marsh cord grass; (2) salt marsh hay and spike grass; (3) reed grass; (4) high tide bush and sea myrtle; and (5) a group of fresh water species found in impounded areas built to attract water fowl. Fifteen such maps cover Delaware's wetlands from the Pennsylvania to the Maryland borders. The mapping technique employed utilizes the General Electric multispectral data processing system. This system is a hybrid analog-digital system designed as an analysis tool to be used by an operator whose own judgment and knowledge of ground truth can be incorporated at any time into the analyzing process. The result is a high speed, cost effective method for producing enhanced photomaps showing a number of spectral classes, each enhanced spectral class being representative of a vegetative species or group of species.

Fluvial islands: First stage of development from nonmigrating (forced) bars and woody-vegetation interactions

NASA Astrophysics Data System (ADS)

Wintenberger, Coraline L.; Rodrigues, Stéphane; Bréhéret, Jean-Gabriel; Villar, Marc

2015-10-01

Fluvial islands can develop from the channel bed by interactions between pioneer trees and bars. Although vegetation recruitment and survival is possible on all bar types, it is easier for trees to survive on nonmigrating bars developed from a change in channel geometry or to the presence of a steady perturbation. This field study details the first stages of development of a vegetated mid-channel, nonmigrating (or forced) bar and its evolution toward an island form. Over six years, analysis of bed topographical changes, vegetation density and roughness, scour and fill depths, sediment grain size and architecture, and excess bed shear stress highlighted a specific signature of trees on topography and grain size segregation. Two depositional processes combining the formation of obstacle marks and upstream-shifting deposition of sediments led to the vertical accretion of the vegetated bar. During the first stage of the bar accretion, bedload sediment supply coming from surrounding channels during floods was identified as a key process modulated by the presence of woody vegetation and a deflection effect induced by the preexisting topography. Grain size segregation between vegetated and bare areas was also highlighted and interpreted as an important process affecting the development of surrounding channels and the degree of disconnection (and hence the speed of development) of a growing island. The heterogeneity of bedload supply can explain why sediment deposition and density of trees are not strictly related. A general conceptual model detailing the first stages of evolution from a bar to an established island is proposed for relatively large lowland rivers.

The effects of anthropogenic land cover change on pollen-vegetation relationships in the American Midwest

USGS Publications Warehouse

Kujawa, Ellen Ruth; Goring, Simon; Dawson, Andria; Calcote, Randy; Grimm, Eric; Hotchkiss, Sara C.; Jackson, Stephen T.; Lynch, Elizabeth A.; McLachlan, Jason S.; St-Jacques, Jeannine-Marie; Umbanhowar, Charles; Williams, John W.

2016-01-01

Fossil pollen assemblages provide information about vegetation dynamics at time scales ranging from centuries to millennia. Pollen-vegetation models and process-based models of dispersal typically assume stable relationships between source vegetation and corresponding pollen in surface sediments, as well as stable parameterizations of dispersal and productivity. These assumptions, however, are largely unevaluated. This paper reports a test of the stability of pollen-vegetation relationships using vegetation and pollen data from the Midwestern region of the United States, during a period of large changes in land use and vegetation driven by Euro-American settlement. We compared a dataset of pollen records for the early settlement-era with three other datasets of pollen and forest composition for two time periods: before Euro-American settlement, and the late 20th century. Results from generalized linear models for thirteen genera indicate that pollen-vegetation relationships significantly differ (p < 0.05) between pre-settlement and the modern era for several genera: Fagus, Betula, Tsuga, Quercus, Pinus, and Picea. The estimated pollen source radius for the 8 km gridded vegetation data and associated pollen data is 25–85 km, consistent with prior studies using similar methods and spatial resolutions.Hence, the rapid changes in land cover associated with the Anthropocene affect the accuracy of ecological predictions for both the future and the past. In the Anthropocene, paleoecology should move beyond the assumption that pollen-vegetation relationships are stable over time. Multi-temporal calibration datasets are increasingly possible and enable paleoecologists to better understand the complex processes governing pollen-vegetation relationships through space and time.

Carbon Inputs From Riparian Vegetation Limit Oxidation of Physically Bound Organic Carbon Via Biochemical and Thermodynamic Processes

NASA Astrophysics Data System (ADS)

Graham, Emily B.; Tfaily, Malak M.; Crump, Alex R.; Goldman, Amy E.; Bramer, Lisa M.; Arntzen, Evan; Romero, Elvira; Resch, C. Tom; Kennedy, David W.; Stegen, James C.

2017-12-01

In light of increasing terrestrial carbon (C) transport across aquatic boundaries, the mechanisms governing organic carbon (OC) oxidation along terrestrial-aquatic interfaces are crucial to future climate predictions. Here we investigate the biochemistry, metabolic pathways, and thermodynamics corresponding to OC oxidation in the Columbia River corridor using ultrahigh-resolution C characterization. We leverage natural vegetative differences to encompass variation in terrestrial C inputs. Our results suggest that decreases in terrestrial C deposition associated with diminished riparian vegetation induce oxidation of physically bound OC. We also find that contrasting metabolic pathways oxidize OC in the presence and absence of vegetation and—in direct conflict with the "priming" concept—that inputs of water-soluble and thermodynamically favorable terrestrial OC protect bound-OC from oxidation. In both environments, the most thermodynamically favorable compounds appear to be preferentially oxidized regardless of which OC pool microbiomes metabolize. In turn, we suggest that the extent of riparian vegetation causes sediment microbiomes to locally adapt to oxidize a particular pool of OC but that common thermodynamic principles govern the oxidation of each pool (i.e., water-soluble or physically bound). Finally, we propose a mechanistic conceptualization of OC oxidation along terrestrial-aquatic interfaces that can be used to model heterogeneous patterns of OC loss under changing land cover distributions.

Vegetation Coverage Mapping and Soil Effect Correction in Estimating Vegetation Water Content and Dry Biomass from Satellites

NASA Astrophysics Data System (ADS)

Huang, J.; Chen, D.

2005-12-01

Vegetation water content (VWC) attracts great research interests in hydrology research in recent years. As an important parameter describing the horizontal expansion of vegetation, vegetation coverage is essential to implement soil effect correction for partially vegetated fields to estimate VWC accurately. Ground measurements of corn and soybeans in SMEX02 resulted in an identical expolinear relationship between vegetation coverage and leaf area index (LAI), which is used for vegetation coverage mapping. Results illustrated two parts of LAI growth quantitatively: the horizontal expansion of leaf coverage and the vertical accumulation of leaf layers. It is believed that the former part contributes significantly to LAI growth at initial vegetation growth stage and the latter is more dominant after vegetation coverage reaches a certain level. The Normalized Difference Water Index (NDWI) using short-wave infrared bands is convinced for its late saturation at high LAI values, in contrast to the Normalized Difference Vegetation Index (NDVI). NDWI is then utilized to estimate LAI, via another expolinear relationship, which is evidenced having vegetation species independency in study of corn and soybeans in SMEX02 sites. It is believed that the surface reflectance measured at satellites spectral bands are the mixed results of signals reflected from vegetation and bare soil, especially at partially vegetated fields. A simple linear mixture model utilizing vegetation coverage information is proposed to correct soil effect in such cases. Surface reflectance fractions for -rpure- vegetation are derived from the model. Comparing with ground measurements, empirical models using soil effect corrected vegetation indices to estimate VWC and dry biomass (DB) are generated. The study enhanced the in-depth understanding of the mechanisms how vegetation growth takes effect on satellites spectral reflectance with and without soil effect, which are particularly useful for modeling in

Survey of Nitrate Ion Concentrations in Vegetables Cultivated in Plant Factories: Comparison with Open-Culture Vegetables.

PubMed

Oka, Yuka; Hirayama, Izumi; Yoshikawa, Mitsuhide; Yokoyama, Tomoko; Iida, Kenji; Iwakoshi, Katsushi; Suzuki, Ayana; Yanagihara, Midori; Segawa, Yukino; Kukimoto, Sonomi; Hamada, Humika; Matsuzawa, Satomi; Tabata, Setsuko; Sasamoto, Takeo

2017-01-01

A survey of nitrate-ion concentrations in plant-factory-cultured leafy vegetables was conducted. 344 samples of twenty-one varieties of raw leafy vegetables were examined using HPLC. The nitrate-ion concentrations in plant-factory-cultured leafy vegetables were found to be LOD-6,800 mg/kg. Furthermore, the average concentration values varied among different leafy vegetables. The average values for plant-factory-cultured leafy vegetables were higher than those of open-cultured leafy vegetables reported in previous studies, such as the values listed in the Standard Tables of Food Composition in Japan- 2015 - (Seventh revised edition). For some plant-factory-cultured leafy vegetables, such as salad spinach, the average values were above the maximum permissible levels of nitrate concentration in EC No 1258/2011; however, even when these plant-factory-cultured vegetables were routinely eaten, the intake of nitrate ions in humans did not exceed the ADI.

Effects of different cooking methods on nutritional and physicochemical characteristics of selected vegetables.

PubMed

Miglio, Cristiana; Chiavaro, Emma; Visconti, Attilio; Fogliano, Vincenzo; Pellegrini, Nicoletta

2008-01-09

The objective of the present study was to evaluate the effect of three common cooking practices (i.e., boiling, steaming, and frying) on phytochemical contents (i.e., polyphenols, carotenoids, glucosinolates, and ascorbic acid), total antioxidant capacities (TAC), as measured by three different analytical assays [Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP), ferric reducing antioxidant power (FRAP)] and physicochemical parameters of three vegetables (carrots, courgettes, and broccoli). Water-cooking treatments better preserved the antioxidant compounds, particularly carotenoids, in all vegetables analyzed and ascorbic acid in carrots and courgettes. Steamed vegetables maintained a better texture quality than boiled ones, whereas boiled vegetables showed limited discoloration. Fried vegetables showed the lowest degree of softening, even though antioxidant compounds were less retained. An overall increase of TEAC, FRAP, and TRAP values was observed in all cooked vegetables, probably because of matrix softening and increased extractability of compounds, which could be partially converted into more antioxidant chemical species. Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a cooking method would be preferred to preserve the nutritional and physicochemical qualities.

Choosing a DIVA: a comparison of emerging digital imagery vegetation analysis techniques

USGS Publications Warehouse

Jorgensen, Christopher F.; Stutzman, Ryan J.; Anderson, Lars C.; Decker, Suzanne E.; Powell, Larkin A.; Schacht, Walter H.; Fontaine, Joseph J.

2013-01-01

Question: What is the precision of five methods of measuring vegetation structure using ground-based digital imagery and processing techniques? Location: Lincoln, Nebraska, USA Methods: Vertical herbaceous cover was recorded using digital imagery techniques at two distinct locations in a mixed-grass prairie. The precision of five ground-based digital imagery vegetation analysis (DIVA) methods for measuring vegetation structure was tested using a split-split plot analysis of covariance. Variability within each DIVA technique was estimated using coefficient of variation of mean percentage cover. Results: Vertical herbaceous cover estimates differed among DIVA techniques. Additionally, environmental conditions affected the vertical vegetation obstruction estimates for certain digital imagery methods, while other techniques were more adept at handling various conditions. Overall, percentage vegetation cover values differed among techniques, but the precision of four of the five techniques was consistently high. Conclusions: DIVA procedures are sufficient for measuring various heights and densities of standing herbaceous cover. Moreover, digital imagery techniques can reduce measurement error associated with multiple observers' standing herbaceous cover estimates, allowing greater opportunity to detect patterns associated with vegetation structure.

Produce from Africa’s Gardens: Potential for Leafy Vegetable and Fruit Fermentations

PubMed Central

Oguntoyinbo, Folarin A.; Fusco, Vincenzina; Cho, Gyu-Sung; Kabisch, Jan; Neve, Horst; Bockelmann, Wilhelm; Huch, Melanie; Frommherz, Lara; Trierweiler, Bernhard; Becker, Biserka; Benomar, Nabil; Gálvez, Antonio; Abriouel, Hikmate; Holzapfel, Wilhelm H.; Franz, Charles M. A. P.

2016-01-01

A rich variety of indigenous fruits and vegetables grow in Africa, which contribute to the nutrition and health of Africa’s populations. Fruits and vegetables have high moisture and are thus inherently prone to accelerated spoilage. Food fermentation still plays a major role in combating food spoilage and foodborne diseases that are prevalent in many of Africa’s resource disadvantaged regions. Lactic acid fermentation is probably the oldest and best-accepted food processing method among the African people, and is largely a home-based process. Fermentation of leafy vegetables and fruits is, however, underutilized in Africa, although such fermented products could contribute toward improving nutrition and food security in this continent, where many are still malnourished and suffer from hidden hunger. Fermentation of leafy vegetables and fruits may not only improve safety and prolong shelf life, but may also enhance the availability of some trace minerals, vitamins and anti-oxidants. Cassava, cow-peas, amaranth, African nightshade, and spider plant leaves have a potential for fermentation, as do various fruits for the production of vinegars or fruit beers and wines. What is needed to accelerate efforts for production of fermented leaves and vegetables is the development of fermentation protocols, training of personnel and scale-up of production methods. Furthermore, suitable starter cultures need to be developed and produced to guarantee the success of the fermentations. PMID:27458430

Vegetation disturbance and maintenance of diversity in intermittently flooded Carolina Bays in South Carolina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirkman, L.K.; Sharitz, R.R.

1994-02-01

The authors manipulated the fire regime and soil disturbance in four grass-dominated Carolina bay wetlands during a prolonged drought period and examined vegetation composition and cover within dominant vegetation types prior to and after treatments. The authors used the seedling emergence technique to determine the role of the seed bank in the recovery process. Burning did not affect richness, evenness, or diversity (all vegetation types combined); however, soil tillage increased diversity, including both evenness and richness. Percent similarity of the vegetation before and after disturbance was greater in the burning treatment than in the tillage treatment, probably due to greatermore » disruption of the rhizomes of the perennial vegetation by tillage. Vegetation types varied in degree of recovery, although dominance was not altered by either treatment. Several native fugitive species increased following disturbance, indicating that species coexistence in these Carolina bay wetlands depends on the life history characteristics of residual vegetation, as well as that of seed bank species.« less

Effects of vegetation canopy on the radar backscattering coefficient

NASA Technical Reports Server (NTRS)

Mo, T.; Blanchard, B. J.; Schmugge, T. J.

1983-01-01

Airborne L- and C-band scatterometer data, taken over both vegetation-covered and bare fields, were systematically analyzed and theoretically reproduced, using a recently developed model for calculating radar backscattering coefficients of rough soil surfaces. The results show that the model can reproduce the observed angular variations of radar backscattering coefficient quite well via a least-squares fit method. Best fits to the data provide estimates of the statistical properties of the surface roughness, which is characterized by two parameters: the standard deviation of surface height, and the surface correlation length. In addition, the processes of vegetation attenuation and volume scattering require two canopy parameters, the canopy optical thickness and a volume scattering factor. Canopy parameter values for individual vegetation types, including alfalfa, milo and corn, were also determined from the best-fit results. The uncertainties in the scatterometer data were also explored.

Vegetation and Soils

Treesearch

Sammy L. King; Mark H. Eisenbies; David Gartner

2000-01-01

Characterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in...

Vegetation map of the greater Denver area, Front Range urban corridor, Colorado

USGS Publications Warehouse

Marr, J.W.; Boyd, W.S.

1979-01-01

Vegetation is one of our most valuable renewable resources; it is the primary producer of organic matter on which all nongreen organisms are dependent for energy, construction materials, aesthetic enjoyment, and other necessities of life. In order to secure the greatest possible returns from the utilization of the different types of vegetation, people need to know what species are present, the ecological processes in which they are involved, and the ways in which they are arranged in the landscape. This vegetation map is designed to help persons in a wide variety of activities to secure that information.

Occurrence and antimicrobial resistance patterns of Listeria monocytogenes isolated from vegetables.

PubMed

de Vasconcelos Byrne, Vanessa; Hofer, Ernesto; Vallim, Deyse Christina; de Castro Almeida, Rogeria Comastri

2016-01-01

Although the consumption of fresh and minimally processed vegetables is considered healthy, outbreaks related to the contamination of these products are frequently reported. Among the food-borne pathogens that contaminate vegetables is Listeria monocytogenes, a ubiquitous organism that exhibits the ability to survive and multiply at refrigerated temperatures. This study aimed to evaluate the occurrence of L. monocytogenes in vegetables as well as the antimicrobial resistance of isolates. The results showed that 3.03% of samples were contaminated with L. monocytogenes, comprising 2.22% of raw vegetables and 5.56% of ready-to-eat vegetables. Multiplex PCR confirmed the virulence potential of the isolates. Antimicrobial resistance profiling showed that 50% of the isolates were susceptible to the antibiotics used. The resistance of one isolate to penicillin G, a commonly employed therapeutic agent, and the presence of serotype 4b, a serotype commonly associated with food-borne outbreaks, could be potential health hazards for consumers. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Transfer of tracers and pesticides in lab scale wetland systems: the role of vegetation

NASA Astrophysics Data System (ADS)

Durst, R.; Imfeld, G.; Lange, J.

2012-04-01

Surface wetlands can collect contaminated runoff from urban or agricultural catchments and have intrinsic physical, chemical and biological retention and removal processes useful for mitigating contaminants, including pesticides, and thus limiting the contamination of aquatic ecosystems. Yet little is known about the transfer of pesticides between wetlands collecting pesticides runoff and groundwater, and the subsequent threat of groundwater contamination. In particular, the influence of wetland vegetation and related processes during pesticide transfer is largely unknown. Here we evaluate the transfer of the widely used herbicide Isoproturon (IPU) and the fungicide Metalaxyl (MTX) with that of Uranine (UR) and Sulphorhodamine (SRB) in a vegetated and a non-vegetated lab-scale wetland. UR and SRB had successfully served as a reference for pesticides in surface wetlands. We filled two 65 cm long and 15 cm diameter borosilicate columns with sediment cores from a wetland, one without and one with vegetation (Phragmites australis, Cav.). When a constant flow-through rate of 0.33 ml min-1 was reached, tracers and pesticides were injected simultaneously and continuously. The hydrological mass balance and tracer concentrations were measured daily at the outlet of the lab-scale wetland. Samples for pesticides and hydrochemical analyses were collected biweekly. The lab-scale wetlands were covered to limit evaporation and light decay of injected compounds. The reactive transfer of compounds in the vegetated and non-vegetated lab-scale wetland was compared based on breakthrough curves (BTC's) and model parameters of the lumped parameter model CXTFIT. The hydrologic balance revealed that the intensity of transpiration and hence plant activity in the lab-scale wetlands progressively decreased and then apparently ceased after about eight days following continuous pesticide injection. In this first phase, no significant difference in the hydrologic balances could be observed

Global-scale analysis of vegetation indices for moderate resolution monitoring of terrestrial vegetation

NASA Astrophysics Data System (ADS)

Huete, Alfredo R.; Didan, Kamel; van Leeuwen, Willem J. D.; Vermote, Eric F.

1999-12-01

Vegetation indices have emerged as important tools in the seasonal and inter-annual monitoring of the Earth's vegetation. They are radiometric measures of the amount and condition of vegetation. In this study, the Sea-viewing Wide Field-of-View sensor (SeaWiFS) is used to investigate coarse resolution monitoring of vegetation with multiple indices. A 30-day series of SeaWiFS data, corrected for molecular scattering and absorption, was composited to cloud-free, single channel reflectance images. The normalized difference vegetation index (NDVI) and an optimized index, the enhanced vegetation index (EVI), were computed over various 'continental' regions. The EVI had a normal distribution of values over the continental set of biomes while the NDVI was skewed toward higher values and saturated over forested regions. The NDVI resembled the skewed distributions found in the red band while the EVI resembled the normal distributions found in the NIR band. The EVI minimized smoke contamination over extensive portions of the tropics. As a result, major biome types with continental regions were discriminable in both the EVI imagery and histograms, whereas smoke and saturation considerably degraded the NDVI histogram structure preventing reliable discrimination of biome types.

Post-fire vegetation dynamics in Portugal

NASA Astrophysics Data System (ADS)

Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

2009-04-01

analysed for some selected areas and a regression model of post-fire recovery was fitted to the recorded values of NDVI. The model allowed characterising the dynamics of the regeneration process. It was found that recovery rates depend on geographical location, fire intensity/severity and type of vegetation cover. Díaz-Delgado, R., Salvador, R. and Pons, X., 1998: Monitoring of plant community regeneration after fire by remote sensing. In L. Traboud (Ed.), Fire management and landscape ecology (pp. 315-324). International Association of Wildland Fire, Fairfield, WA. Pausas, G.J. and Vallejo, V.R., 1999: The role of fire in European Mediterranean Ecosystems. In: E. Chuvieco (Ed.), Remote sensing of large wildfires in the European Mediterranean basin (pp. 3-16). Springer-Verlag. Trigo R.M., Pereira J.M.C., Pereira M.G., Mota B., Calado M.T., DaCamara C.C., Santo F.E., 2006: Atmospheric conditions associated with the exceptional fire season of 2003 in Portugal. International Journal of Climatology 26 (13): 1741-1757 NOV 15 2006.

Field application of glyphosate induces molecular changes affecting vegetative growth processes in leafy spurge

USDA-ARS?s Scientific Manuscript database

Recommended rates of glyphosate for non-cultivated areas destroy the aboveground shoots of the perennial plant leafy spurge. However, such applications cause little or no damage to underground adventitious buds (UABs), and thus the plant readily regenerates vegetatively. High concentrations of glyph...

Spatio-temporal development of vegetation die-off in a submerging coastal marsh

USGS Publications Warehouse

Schepers, Lennert; Kirwan, Matthew; Guntenspergen, Glenn R.; Temmerman, Stijn

2017-01-01

In several places around the world, coastal marsh vegetation is converting to open water through the formation of pools. This is concerning, as vegetation die-off is expected to reduce the marshes' capacity to adapt to sea level rise by vegetation-induced sediment accretion. Quantitative analyses of the spatial and temporal development of marsh vegetation die-off are scarce, although these are needed to understand the bio-geomorphic feedback effects of vegetation die-off on flow, erosion, and sedimentation. In this study, we quantified the spatial and temporal development of marsh vegetation die-off with aerial images from 1938 to 2010 in a submerging coastal marsh along the Blackwater River (Maryland, U.S.A). Our results indicate that die-off begins with conversion of marsh vegetation into bare open water pools that are relatively far (> 75 m) from tidal channels. As vegetation die-off continues, pools expand, and new pools emerge at shorter and shorter distances from channels. Consequently larger pools are found at larger distances from the channels. Our results suggest that the size of the pools and possibly the connection of pools with the tidal channel system have important bio-geomorphic implications and aggravate marsh deterioration. Moreover, we found that the temporal development of vegetation die-off in moderately degraded marshes is similar as the spatial die-off development along a present-day gradient, which indicates that the contemporary die-off gradient might be considered a chronosequence that offers a unique opportunity to study vegetation die-off processes.

Associations between parental feeding practices and child vegetable consumption. Mediation by child cognitions?

PubMed

Melbye, Elisabeth L; Øgaard, Torvald; Øverby, Nina C

2013-10-01

The present study aimed to explore the process in which parental food-related behaviors might influence preadolescent children's vegetable consumption, addressing potential mediating effects of child cognitions. Cross-sectional surveys were performed among 10-12-year-olds and their parents. The child questionnaire included measures of vegetable consumption and child cognitions related to vegetable consumption (i.e. attitudes, social influence, self-efficacy and intention). The parent questionnaire included measures of parental feeding practices adapted from the Comprehensive Feeding Practices Questionnaire. Stepwise regressions were performed to reveal potential mediating effects of child cognitions on the associations between parental feeding practices and child vegetable consumption. Our results suggested a mediating effect of child self-efficacy on the association between parental restrictive behavior and child vegetable consumption. Other potential mediating effects were not supported in this study. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fouling mechanism in ultrafiltration of vegetable oil

NASA Astrophysics Data System (ADS)

Ariono, D.; Wardani, A. K.; Widodo, S.; Aryanti, Putu T. P.; Wenten, I. G.

2018-03-01

Energy efficient and cost-effective separation of impurities from vegetable oil is a great challenge for vegetable oil processing. Several technologies have been developed, including pressurized membrane, chemical treatment, and chemical free separation methods. Among those technologies, ultrafiltration membrane is one of the most attractive processes with low operating pressure and temperature. In this work, hydrophobic polypropylene ultrafiltration membrane was used to remove impurities such as non-dissolved solids from palm kernel oil. Unfortunately, the hydrophobicity of polypropylene membrane leads to significant impact on the reduction of permeate flux due to membrane fouling. This fouling is associated with the accumulation of substances on the membrane surface or within the membrane pores. For better understanding, fouling mechanism that occurred during palm kernel oil ultrafiltration using hydrophobic polypropylene membrane was investigated. The effect of trans-membrane pressure and feed temperature on fouling mechanism was also studied. The result showed that cake formation became the dominant fouling mechanism up to 50 min operation of palm kernel oil ultrafiltration. Furthermore, the fouling mechanism was not affected by the increase of trans-membrane pressure and feed temperature.

Microbiological Spoilage of Fruits and Vegetables

NASA Astrophysics Data System (ADS)

Barth, Margaret; Hankinson, Thomas R.; Zhuang, Hong; Breidt, Frederick

Consumption of fruit and vegetable products has dramatically increased in the United States by more than 30% during the past few decades. It is also estimated that about 20% of all fruits and vegetables produced is lost each year due to spoilage. The focus of this chapter is to provide a general background on microbiological spoilage of fruit and vegetable products that are organized in three categories: fresh whole fruits and vegetables, fresh-cut fruits and vegetables, and fermented or acidified vegetable products. This chapter will address characteristics of spoilage microorganisms associated with each of these fruit and vegetable categories including spoilage mechanisms, spoilage defects, prevention and control of spoilage, and methods for detecting spoilage microorganisms.

Airborne Laser Scanning - based vegetation classification in grasslands: a feasibility study

NASA Astrophysics Data System (ADS)

Zlinszky, András; Vári, Ágnes; Deák, Balázs; Mücke, Werner; Székely, Balázs

2013-04-01

Airborne Laser Scanning is traditionally used for topography mapping, exploiting its ability to map terrain elevation under vegetation cover. Parallel to this, the application of ALS for vegetation classification and mapping of ecological variables is rapidly emerging. Point clouds surveyed by ALS provide accurate representations of vegetation structure and are therefore considered suitable for mapping vegetation classes as long as their vertical structure is characteristic. For this reason, most ALS-based vegetation mapping studies have been carried out in forests, with some rare applications for shrublands or tall grass vegetation such as reeds. The use of remote-sensing derived vegetation maps is widespread in ecological research and is also gaining importance in practical conservation. There is an increasing demand for reliable, high-resolution datasets covering large protected areas. ALS can provide both the coverage and the high resolution, and can prove to be an economical solution due to the potential for automatic processing and the wide range of uses that allows spreading costs. Grasslands have a high importance in nature conservation as due to the drastical land use changes (arable lands, afforestation, fragmentation by linear structures) in the last centuries the extent of these habitats have been considerably reduced. Among the habitat types protected by the Habitat Directive of the Natura 2000 system, several grassland habitat types (e.g. hay meadows, dry grasslands harbouring rare Orchid species) have special priority for conservation. For preserving these habitat types application of a proper management - including mowing or grazing - has a crucial role. Therefore not only the mapping of the locations of habitats but the way of management is needed for representing the natural processes. The objective of this study was to test the applicability of airborne laser scanning for ecological vegetation mapping in and around grasslands. The study site is

Recall of vegetable eating affects future predicted enjoyment and choice of vegetables in British University undergraduate students.

PubMed

Robinson, Eric; Blissett, Jackie; Higgs, Suzanne

2011-10-01

Predictions about enjoyment of future experiences are influenced by recalling similar past experiences. However, little is known about the relationship between hedonic memories of past eating episodes and future eating behavior. We investigated recall of previous experiences of eating vegetables and the effect of recall on future predicted liking for and consumption of vegetables. British University undergraduate students were asked to retrieve memories of previous occasions when they ate vegetables and were asked to rate how enjoyable those experiences were (Study 1, n=54). The effect of different types of memory recall (including vegetable eating recall) and visualization of someone else eating vegetables (to control for priming effects) on predicted likelihood of choosing vegetables and predicted enjoyment of eating vegetables was examined (Study 2, n=95). Finally, the effect of recalling vegetable eating memories on actual food choice from a buffet was assessed (Study 3, n=63). It is reported that people recall positive memories of past vegetable consumption (P<0.05) and that reminding people of these experiences results in higher predicted future liking for vegetables (P<0.05) and choice of a larger portion size of vegetables (P<0.05) compared with recall of a personal nonfood memory, a nonvegetable food memory, or visualization of someone else enjoying eating vegetables (increase of approximately 70% in vegetable portion size compared to controls). The results suggest that recall of previous eating experiences could be a potential strategy for altering food choices. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Factors influencing fruit and vegetable intake among urban Fijians: A qualitative study.

PubMed

Morgan, E H; Vatucawaqa, P; Snowdon, W; Worsley, A; Dangour, A D; Lock, K

2016-06-01

Low fruit and vegetable intake is an important risk factor for micronutrient deficiencies and non-communicable diseases, but many people worldwide, including most Fijians, eat less than the World Health Organization recommended amount. The present qualitative study explores factors that influence fruit and vegetable intake among 57 urban Fijians (50 women, 7 men) of indigenous Fijian (iTaukei) and South Asian (Indian) descent. Eight focus group discussions were held in and around Suva, Fiji's capital and largest urban area, which explored motivation for eating fruit and vegetables, understandings of links to health and disease, availability and sources, determinants of product choice, and preferred ways of preparing and eating fruit and vegetables. Data were analysed using thematic content analysis. Regardless of ethnicity, participants indicated that they enjoyed and valued eating fruit and vegetables, were aware of the health benefits, and had confidence in their cooking skills. In both cultures, fruit and vegetables were essential components of traditional diets. However, increasing preferences for processed and imported foods, and inconsistent availability and affordability of high-quality, low-priced, fresh produce, were identified as important barriers. The findings indicate that efforts to improve fruit and vegetable intake in urban Fijians should target the stability of the domestic fruit and vegetable supply and access. Copyright © 2016 Elsevier Ltd. All rights reserved.

Abnormal Functional MRI BOLD Contrast in the Vegetative State after Severe Traumatic Brain Injury

ERIC Educational Resources Information Center

Heelmann, Volker

2010-01-01

For the rehabilitation process, the treatment of patients surviving brain injury in a vegetative state is still a serious challenge. The aim of this study was to investigate patients exhibiting severely disturbed consciousness using functional magnetic resonance imaging. Five cases of posttraumatic vegetative state and one with minimal…

A Robust Gold Deconvolution Approach for LiDAR Waveform Data Processing to Characterize Vegetation Structure

NASA Astrophysics Data System (ADS)

Zhou, T.; Popescu, S. C.; Krause, K.; Sheridan, R.; Ku, N. W.

2014-12-01

Increasing attention has been paid in the remote sensing community to the next generation Light Detection and Ranging (lidar) waveform data systems for extracting information on topography and the vertical structure of vegetation. However, processing waveform lidar data raises some challenges compared to analyzing discrete return data. The overall goal of this study was to present a robust de-convolution algorithm- Gold algorithm used to de-convolve waveforms in a lidar dataset acquired within a 60 x 60m study area located in the Harvard Forest in Massachusetts. The waveform lidar data was collected by the National Ecological Observatory Network (NEON). Specific objectives were to: (1) explore advantages and limitations of various waveform processing techniques to derive topography and canopy height information; (2) develop and implement a novel de-convolution algorithm, the Gold algorithm, to extract elevation and canopy metrics; and (3) compare results and assess accuracy. We modeled lidar waveforms with a mixture of Gaussian functions using the Non-least squares (NLS) algorithm implemented in R and derived a Digital Terrain Model (DTM) and canopy height. We compared our waveform-derived topography and canopy height measurements using the Gold de-convolution algorithm to results using the Richardson-Lucy algorithm. Our findings show that the Gold algorithm performed better than the Richardson-Lucy algorithm in terms of recovering the hidden echoes and detecting false echoes for generating a DTM, which indicates that the Gold algorithm could potentially be applied to processing of waveform lidar data to derive information on terrain elevation and canopy characteristics.

On the Mineral and Vegetal Oils Used as Electroinsulation in Transformers

NASA Astrophysics Data System (ADS)

Şerban, Mariana; Sângeorzan, Livia; Helerea, Elena

Due to the relatively large availability and reduced price, the mineral transformer oils are widely used as electrical insulating liquids. However, mineral oil drastically degrades over time in service. New efforts were made to improve mineral oils characteristics, and other types of liquids like vegetal oils are proposed. This paper deals with new comparative tests on mineral and vegetal oils using as indicator the electric strength. The samples of non-additive mineral oil type TR 30 and vegetal oils of rape, sunflower and corn have been tested with increasing voltage of 60 Hz using different electrodes. The obtained data have been statistical processed. The analyze shows different average values of electrical strength for the different type of sample. New method of testing through electrical breakdown is proposed. Experimental data confirms that it is possible to use as electroinsulation organic vegetal oils in power transformers.

Vegetable behavioral tool demonstrates validity with MyPlate vegetable cups and carotenoid and inflammatory biomarkers.

PubMed

Townsend, Marilyn S; Shilts, Mical K; Styne, Dennis M; Drake, Christiana; Lanoue, Louise; Woodhouse, Leslie; Allen, Lindsay H

2016-12-01

Young children are not meeting recommendations for vegetable intake. Our objective is to provide evidence of validity and reliability for a pictorial vegetable behavioral assessment for use by federally funded community nutrition programs. Parent/child pairs (n=133) from Head Start and the Special Supplemental Nutrition Program for Women, Infants and Children [WIC] provided parent-administered vegetable tools, three child 24-hour diet recalls, child blood sample and measured heights/weights. The 10-item Focus on Veggies scale, with an alpha of .83 and a stability reliability coefficient of .74, was positively related to vegetables in cup equivalents [p≤.05]; dietary intakes of folate, vitamin C, β-carotene, potassium and magnesium [p≤.05-.01]; and soluble fiber [p≤.001]. The child vegetable scores were related to the parent's mediators [p≤.00001] and vegetable behaviors [p≤.00001]. Children's plasma inflammatory markers were negatively related to the 10 item scale [p≤.05] and are indicators of the child's health status. The positive relationship between the serum carotenoid index and a sub-scale of child vegetable behaviors offered additional support for criterion validity [p≤.05]. Finally, the inverse relationship of BMI-for-age percentile one year post baseline and a sub-scale of child vegetable behaviors supported the predictive validity [p≤.05]. Focus on Veggies, a simple assessment tool, can inform practitioners about the child's health status. A child with a high score, shows a healthful profile with a lower inflammation index, higher carotenoid index, lower BMI and higher vegetable intake. In conclusion, validity of Focus on Veggies has been demonstrated using vegetable cup equivalents and micronutrient intakes, anthropometry and blood biomarkers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modelling of vegetation-driven morphodynamics in braided rivers.

NASA Astrophysics Data System (ADS)

Stecca, Guglielmo; Fedrizzi, Davide; Hicks, Murray; Measures, Richard; Zolezzi, Guido; Bertoldi, Walter; Tal, Michal

2017-04-01

River planform results from the complex interaction between flow, sediment transport and vegetation, and can evolve following a change in these controls. The braided planform of New Zealand's Lower Waitaki River, for instance, is endangered by the action of artificially-introduced alien vegetation, which spread across the braidplain following the reduction in magnitude of floods by hydropower dam construction. This vegetation, by encouraging flow concentration into the main channel, would likely promote a shift towards a single-thread morphology if it was not artificially removed within a central fairway. The purpose of this work is to study the evolution of braided rivers such as the Waitaki under different management scenarios through two-dimensional numerical modelling. The construction of a suitable model represents a task in itself, since a modelling framework coupling all the relevant processes is not yet readily available. Our starting point is the physics-based GIAMT2D numerical model, which solves two-dimensional flow and bedload transport in wet/dry domains, and recently modified by the inclusion of a rule-based bank erosion model. We have further developed this model by adding a vegetation module, which accounts in a simplified manner for time-evolving biomass density, adjusting local flow roughness, critical shear stress for sediment transport, and bank erodibility accordingly. Our goal is to use the model to study decadal-scale evolution of a reach on the Waitaki River and predict planform characteristics under different vegetation management scenarios. Here we present the results of a preliminary application of the model to reproduce the morphodynamic evolution of a braided channel in a set of flume experiments that used alfalfa as vegetation. The experiments began with a braided morphology that spontaneoulsy formed at constant flow over a bed of bare uniform sand. The planform transitioned towards single-thread when this discharge was repeatedly

Monitoring vegetation water uptake in a semiarid riparian corridor

NASA Astrophysics Data System (ADS)

Robinson, J.; Ochoa, C. G.; Leonard, J.

2015-12-01

With a changing global climate and growing demand for water throughout the world, responsible and sustainable land and water resource management practices are becoming increasingly important. Accounting for the amount of water used by riparian vegetation is a critical element for better managing water resources in arid and semiarid environments. The objective of this study was to determine water uptake by selected riparian vegetative species in a semiarid riparian corridor in North-Central Oregon. Exo-skin sap flow sensors (Dynamax, Houston, TX, U.S.A.) were used to measure sap flux in red alder (Alnus rubra) trees, the dominant overstory vegetation at the field site. Xylem sap flow data was collected from selected trees at the field site and in a greenhouse setting. Transpiration rates were determined based on an energy balance method, which makes it possible to estimate the mass flow of sap by measuring the velocity of electrical heat pulses through the plant stem. Preliminary field results indicate that red alder tree branches of about 1 inch diameter transpire between 2 and 6 kg of water/day. Higher transpiration rates of up to 7.3 kg of water/day were observed under greenhouse conditions. Streamflow and stream water temperature, vegetation characteristics, and meteorological data were analyzed in conjunction with transpiration data. Results of this study provide insight on riparian vegetation water consumption in water scarce ecosystems. This study is part of an overarching project focused on climate-vegetation interactions and ecohydrologic processes in arid and semiarid landscapes.

Vegetation index anomaly response to varying lengths of drought across vegetation and climatic gradients in Hawaii

NASA Astrophysics Data System (ADS)

Lucas, M.; Miura, T.; Trauernicht, C.; Frazier, A. G.

2017-12-01

A drought which results in prolonged and extended deficit in naturally available water supply and creates multiple stresses across ecosystems is classified as an ecological drought. Detecting and understanding the dynamics and response of such droughts in tropical systems, specifically across various vegetation and climatic gradients is fairly undetermined, yet increasingly important for better understandings of the ecological effects of drought. To understanding the link between what lengths and intensities of known meteorological drought triggers detectable ecological vegetation responses, a landscape scale regression analysis evaluating the response (slope) and relationship strength (R-squared) of several cumulative SPI (standard precipitation index) lengths(1, 3, 6, 12, 18, 24, 36, 48, and 60 month), to various satellite derived monthly vegetation indices anomalies (NDVI, EVI, EVI2, and LSWI) was performed across a matrix of dominant vegetation covers (grassland, shrubland, and forest) and climatic moisture zones (arid, dry, mesic, and wet). The nine different SPI lags across these climactic and vegetation gradients was suggest that stronger relationships and steeper slopes were found in dryer climates (across all vegetation covers) and finer vegetation types (across all moisture zones). Overall NDVI, EVI and EVI2 showed the best utility in these dryer climatic zones across all vegetation types. Within arid and dry areas "best" fits showed increasing lengths of cumulative SPI were with increasing vegetation coarseness respectively. Overall these findings suggest that rainfall driven drought may have a stronger impact on the ecological condition of vegetation in water limited systems with finer vegetation types ecologically responding more rapidly to meteorological drought events than coarser woody vegetation systems. These results suggest that previously and newly documented trends of decreasing rainfall and increasing drought in Hawaiian drylands may have

Site specific diel methane emission mechanisms in landfills: A field validated process based on vegetation and climate factors.

PubMed

Xin, Danhui; Hao, Yongxia; Shimaoka, Takayuki; Nakayama, Hirofumi; Chai, Xiaoli

2016-11-01

Diel methane emission fluxes from a landfill that was covered by vegetation were investigated to reveal the methane emission mechanisms based on the interaction of vegetation characteristics and climate factors. The methane emissions showed large variation between daytime and nighttime, and the trend of methane emissions exhibited clear bimodal patterns from both Setaria viridis- and Neyraudia reynaudiana-covered areas. Plants play an important role in methane transportation as well as methane oxidation. The notable decrease in methane emissions after plants were cut suggests that methane transportation via plants is the primary way of methane emissions in the vegetated areas of landfill. Within plants, the methane emission fluxes were enhanced due to a convection mechanism. Given that the methane emission flux is highly correlated with the solar radiation during daytime, the convection mechanism could be attributed to the increase in solar radiation. Whereas the methane emission flux is affected by a combined impact of the wind speed and pedosphere characteristics during nighttime. An improved understanding of the methane emission mechanisms in vegetated landfills is expected to develop a reliable model for landfill methane emissions and to attenuate greenhouse gas emissions from landfills. Copyright © 2016 Elsevier Ltd. All rights reserved.

Wetland Vegetation Integrity Assessment with Low Altitude Multispectral Uav Imagery

NASA Astrophysics Data System (ADS)

Boon, M. A.; Tesfamichael, S.

2017-08-01

The use of multispectral sensors on Unmanned Aerial Vehicles (UAVs) was until recently too heavy and bulky although this changed in recent times and they are now commercially available. The focus on the usage of these sensors is mostly directed towards the agricultural sector where the focus is on precision farming. Applications of these sensors for mapping of wetland ecosystems are rare. Here, we evaluate the performance of low altitude multispectral UAV imagery to determine the state of wetland vegetation in a localised spatial area. Specifically, NDVI derived from multispectral UAV imagery was used to inform the determination of the integrity of the wetland vegetation. Furthermore, we tested different software applications for the processing of the imagery. The advantages and disadvantages we experienced of these applications are also shortly presented in this paper. A JAG-M fixed-wing imaging system equipped with a MicaScene RedEdge multispectral camera were utilised for the survey. A single surveying campaign was undertaken in early autumn of a 17 ha study area at the Kameelzynkraal farm, Gauteng Province, South Africa. Structure-from-motion photogrammetry software was used to reconstruct the camera position's and terrain features to derive a high resolution orthoretified mosaic. MicaSense Atlas cloud-based data platform, Pix4D and PhotoScan were utilised for the processing. The WET-Health level one methodology was followed for the vegetation assessment, where wetland health is a measure of the deviation of a wetland's structure and function from its natural reference condition. An on-site evaluation of the vegetation integrity was first completed. Disturbance classes were then mapped using the high resolution multispectral orthoimages and NDVI. The WET-Health vegetation module completed with the aid of the multispectral UAV products indicated that the vegetation of the wetland is largely modified ("D" PES Category) and that the condition is expected to

Development of the B.C. Vegetation Inventory Training Program

Treesearch

Norm Shaw

2000-01-01

During the development of the B.C. Vegetation Resources Inventory, it was recognized that success would depend on the ability to implement and actually carry out the design. It was accepted that a training program would be an integral component of the inventory process. A formal process tied to basic principles of committee structure and recognition of work well done...

Interpretation of surface and planetary directional albedos for vegetated regions

NASA Technical Reports Server (NTRS)

Cess, Robert D.; Vulis, Inna L.

1989-01-01

An atmospheric solar radiation model has been coupled with surface reflectance measurements for two vegetation types, pasture land and savannah, in order to address several issues associated with understanding the directional planetary albedo; i.e., the dependence of planetary albedo upon solar zenith angle. These include an elucidation of processes that influence the variation of planetary albedo with solar zenith angle, as well as emphasizing potential problems associated with converting narrowband planetary albedo measurements to broadband quantities. It is suggested that, for vegetated surfaces, this latter task could be somewhat formidable, since the model simulations indicate that narrowband to broadband conversions strongly depend upon vegetation type. A further aspect of this paper is to illustrate a procedure by which reciprocity inconsistencies within a bidirectional reflectance dataset, if they are not too severe, can be circumvented.

Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

NASA Astrophysics Data System (ADS)

Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S. L.; Poulter, B.; Viovy, N.

2013-04-01

Stand-replacing fires are the dominant fire type in North American boreal forest and leave a historical legacy of a mosaic landscape of different aged forest cohorts. To accurately quantify the role of fire in historical and current regional forest carbon balance using models, one needs to explicitly simulate the new forest cohort that is established after fire. The present study adapted the global process-based vegetation model ORCHIDEE to simulate boreal forest fire CO2 emissions and follow-up recovery after a stand-replacing fire, with representation of postfire new cohort establishment, forest stand structure and the following self-thinning process. Simulation results are evaluated against three clusters of postfire forest chronosequence observations in Canada and Alaska. Evaluation variables for simulated postfire carbon dynamics include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index (LAI), and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). The model simulation results, when forced by local climate and the atmospheric CO2 history on each chronosequence site, generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with measurement accuracy (for CO2 flux ~100 g C m-2 yr-1, for biomass carbon ~1000 g C m-2 and for soil carbon ~2000 g C m-2). We find that current postfire forest carbon sink on evaluation sites observed by chronosequence methods is mainly driven by historical atmospheric CO2 increase when forests recover from fire disturbance. Historical climate generally exerts a negative effect, probably due to increasing water stress caused by significant temperature increase without sufficient increase in precipitation. Our simulation results demonstrate that a global

Biogeomorphological influence of slope processes and sedimentology on vascular talus vegetation in the southern Cascades, California

NASA Astrophysics Data System (ADS)

Pérez, Francisco L.

2012-02-01

The vascular vegetation of alpine talus slopes between 2035 and 3095 m altitude was studied at Lassen Volcanic National Park (California) in the Cascade Range. Taluses show a diverse flora, with 79 plant species; growth forms include coniferous trees, shrubs, suffrutices, herbs, graminoids, and ferns. Spatial patterns of plant distribution were studied along 40 point-intercept transects. Plant cover was low (0-32.7%) on all slopes, spatially variable, and showed no consistent trends. Sedimentological characteristics were determined by photosieving next to 1500 plants; this census indicated preferential plant growth on blocks and cobbles, with 43.2% and 23.3% of the plants growing on these stones, respectively; fewer specimens were rooted on pebbles (13%) or on stone-free gravel areas (20.5%). Growth forms displayed different substrate preferences: 92.5% of the shrubs and 83% of the suffrutices colonized blocks or cobbles, but only 57.2% of the herbs and 59.8% of the graminoids grew on large stones. Plants are associated with large clasts because (1) coarse talus is more stable than fine sediment areas, which are more frequently disturbed by various geomorphic processes, and (2) large stones help conserve substrate water beneath them while moisture quickly evaporates from fine debris. Root patterns were studied for 30 plant species; 10 specimens for each species were excavated and inspected, and several root growth ratios calculated. All species exhibited pronounced root asymmetry, as roots for most plants grew upslope from their shoot base. For 23 species, all specimens had 100% of their roots growing upslope; for the other 7 species, 92.2-99.3% of below-ground biomass extended uphill. This uneven root distribution is ascribed to continual substrate instability and resulting talus shift; as cascading debris progressively buries roots and stems, plants are gradually pushed and/or stretched downhill. Various disturbance events affect root development. Slope erosion

Predicting Ecologically Important Vegetation Variables from Remotely Sensed Optical/Radar Data Using Neural Networks

NASA Technical Reports Server (NTRS)

Kimes, Daniel S.; Nelson, Ross F.

1998-01-01

A number of satellite sensor systems will collect large data sets of the Earth's surface during NASA's Earth Observing System (EOS) era. Efforts are being made to develop efficient algorithms that can incorporate a wide variety of spectral data and ancillary data in order to extract vegetation variables required for global and regional studies of ecosystem processes, biosphere-atmosphere interactions, and carbon dynamics. These variables are, for the most part, continuous (e.g. biomass, leaf area index, fraction of vegetation cover, vegetation height, vegetation age, spectral albedo, absorbed photosynthetic active radiation, photosynthetic efficiency, etc.) and estimates may be made using remotely sensed data (e.g. nadir and directional optical wavelengths, multifrequency radar backscatter) and any other readily available ancillary data (e.g., topography, sun angle, ground data, etc.). Using these types of data, neural networks can: 1) provide accurate initial models for extracting vegetation variables when an adequate amount of data is available; 2) provide a performance standard for evaluating existing physically-based models; 3) invert multivariate, physically based models; 4) in a variable selection process, identify those independent variables which best infer the vegetation variable(s) of interest; and 5) incorporate new data sources that would be difficult or impossible to use with conventional techniques. In addition, neural networks employ a more powerful and adaptive nonlinear equation form as compared to traditional linear, index transformations, and simple nonlinear analyses. These neural networks attributes are discussed in the context of the authors' investigations of extracting vegetation variables of ecological interest.

Geomorphic and vegetative recovery processes along modified stream channels of West Tennessee

USGS Publications Warehouse

Simon, Andrew; Hupp, C.R. Tennessee

1992-01-01

Hundreds of miles of streams in West Tennessee have been channelized or otherwise modt@ed since the turn of century. After all or parts of a stream are straightened, dredged, or cleared, systematic hydrologic, geomorphic, and ecologic processes collectively begin to reduce energy conditions towards the premodified state. One hundred and five sites along 15 streams were studied in the Obion, Forked Deer, Hatchie, and Wolf River basins. All studied streams, except the Hatchie River, have had major channel modi@cation along all or parts of their courses. Bank material shear-strength properties were determined through drained borehole-shear testing (168 tests) and used to interpret present critical bank conditions and factors of safety, and to estimate future channel-bank stability. Mean values of cohesive strength and angle of internal friction were 1.26 pounds per square inch and 30.1 degrees, respectively. Dendrogeomorphic analyses were made using botanical evidence of channel-bank failures to determine rates of channel widening; buried riparian stems were analyzed to determine rates of bank accretion. Channel bed-level changes through time and space were represented by a power equation. Plant ecological analyses were ma& to infer relative bank stability, to identify indicator species of the stage of bank recovery, and to determine patterns of vegetation development through the course of channel evolution. Quantitative data on morphologic changes were used with previously developed six-stage models of channel evolution and bank-slope development to estimate trends of geomorphic and ecologic processes and forms through time. Immediately after channel modr@cations, a 10- to 1%yearperiod of channel-bed degradation ensues at and upstream from the most recent modifications (area of maximum disturbance). Channel-bed lowering by &gradation was as much as 20 feet along some stream reaches. Downstream from the area of maximum disturbance, the bed was aggraded by the

Vegetable soybean tolerance to pyroxasulfone

USDA-ARS?s Scientific Manuscript database

If registered for use on vegetable soybean, pyroxasulfone would fill an important gap in weed management systems in the crop. In order to determine the potential crop injury risk of pyroxasulfone on vegetable soybean, the objective of this work was to quantify vegetable soybean tolerance to pyroxasu...

Hidden vegetables: an effective strategy to reduce energy intake and increase vegetable intake in adults.

PubMed

Blatt, Alexandria D; Roe, Liane S; Rolls, Barbara J

2011-04-01

The overconsumption of energy-dense foods leads to excessive energy intakes. The substitution of low-energy-dense vegetables for foods higher in energy density can help decrease energy intakes but may be difficult to implement if individuals dislike the taste of vegetables. We investigated whether incorporating puréed vegetables to decrease the energy density of entrées at multiple meals reduced daily energy intakes and increased daily vegetable intakes. In this crossover study, 20 men and 21 women ate ad libitum breakfast, lunch, and dinner in the laboratory once a week for 3 wk. Across conditions, entrées at meals varied in energy density from standard versions (100% condition) to reduced versions (85% and 75% conditions) by the covert incorporation of 3 or 4.5 times the amount of puréed vegetables. Entrées were accompanied by unmanipulated side dishes. Participants rated their hunger and fullness before and after meals. Subjects consumed a consistent weight of foods across conditions of energy density; thus, the daily energy intake significantly decreased by 202 ± 60 kcal in the 85% condition (P < 0.001) and by 357 ± 47 kcal in the 75% condition (P < 0.0001). Daily vegetable consumption significantly increased from 270 ± 17 g of vegetables in the 100% condition to 487 ± 25 g of vegetables in the 75% condition (P < 0.0001). Despite the decreased energy intake, ratings of hunger and fullness did not significantly differ across conditions. Entrées were rated as similar in palatability across conditions. Large amounts of puréed vegetables can be incorporated into various foods to decrease the energy density. This strategy can lead to substantial reductions in energy intakes and increases in vegetable intakes. This trial was registered at clinicaltrials.gov as NCT01165086.

40 CFR 230.43 - Vegetated shallows.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Vegetated shallows. 230.43 Section 230... Special Aquatic Sites § 230.43 Vegetated shallows. (a) Vegetated shallows are permanently inundated areas... reducing light penetration and hence photosynthesis; and (5) changing the capacity of a vegetated shallow...

Development of indicators of vegetation recovery based on time series analysis of SPOT Vegetation data

NASA Astrophysics Data System (ADS)

Lhermitte, S.; Tips, M.; Verbesselt, J.; Jonckheere, I.; Van Aardt, J.; Coppin, Pol

2005-10-01

Large-scale wild fires have direct impacts on natural ecosystems and play a major role in the vegetation ecology and carbon budget. Accurate methods for describing post-fire development of vegetation are therefore essential for the understanding and monitoring of terrestrial ecosystems. Time series analysis of satellite imagery offers the potential to quantify these parameters with spatial and temporal accuracy. Current research focuses on the potential of time series analysis of SPOT Vegetation S10 data (1999-2001) to quantify the vegetation recovery of large-scale burns detected in the framework of GBA2000. The objective of this study was to provide quantitative estimates of the spatio-temporal variation of vegetation recovery based on remote sensing indicators. Southern Africa was used as a pilot study area, given the availability of ground and satellite data. An automated technique was developed to extract consistent indicators of vegetation recovery from the SPOT-VGT time series. Reference areas were used to quantify the vegetation regrowth by means of Regeneration Indices (RI). Two kinds of recovery indicators (time and value- based) were tested for RI's of NDVI, SR, SAVI, NDWI, and pure band information. The effects of vegetation structure and temporal fire regime features on the recovery indicators were subsequently analyzed. Statistical analyses were conducted to assess whether the recovery indicators were different for different vegetation types and dependent on timing of the burning season. Results highlighted the importance of appropriate reference areas and the importance of correct normalization of the SPOT-VGT data.

Ingression-type cell migration drives vegetal endoderm internalisation in the Xenopus gastrula

PubMed Central

Wen, Jason WH

2017-01-01

During amphibian gastrulation, presumptive endoderm is internalised as part of vegetal rotation, a large-scale movement that encompasses the whole vegetal half of the embryo. It has been considered a gastrulation process unique to amphibians, but we show that at the cell level, endoderm internalisation exhibits characteristics reminiscent of bottle cell formation and ingression, known mechanisms of germ layer internalisation. During ingression proper, cells leave a single-layered epithelium. In vegetal rotation, the process occurs in a multilayered cell mass; we refer to it as ingression-type cell migration. Endoderm cells move by amoeboid shape changes, but in contrast to other instances of amoeboid migration, trailing edge retraction involves ephrinB1-dependent macropinocytosis and trans-endocytosis. Moreover, although cells are separated by wide gaps, they are connected by filiform protrusions, and their migration depends on C-cadherin and the matrix protein fibronectin. Cells move in the same direction but at different velocities, to rearrange by differential migration. PMID:28826499

Terrestrial Feedbacks Incorporated in Global Vegetation Models through Observed Trait-Environment Responses

NASA Astrophysics Data System (ADS)

Bodegom, P. V.

2015-12-01

Most global vegetation models used to evaluate climate change impacts rely on plant functional types to describe vegetation responses to environmental stresses. In a traditional set-up in which vegetation characteristics are considered constant within a vegetation type, the possibility to implement and infer feedback mechanisms are limited as feedback mechanisms will likely involve a changing expression of community trait values. Based on community assembly concepts, we implemented functional trait-environment relationships into a global dynamic vegetation model to quantitatively assess this feature. For the current climate, a different global vegetation distribution was calculated with and without the inclusion of trait variation, emphasizing the importance of feedbacks -in interaction with competitive processes- for the prevailing global patterns. These trait-environmental responses do, however, not necessarily imply adaptive responses of vegetation to changing conditions and may locally lead to a faster turnover in vegetation upon climate change. Indeed, when running climate projections, simulations with trait variation did not yield a more stable or resilient vegetation than those without. Through the different feedback expressions, global and regional carbon and water fluxes were -however- strongly altered. At a global scale, model projections suggest an increased productivity and hence an increased carbon sink in the next decades to come, when including trait variation. However, by the end of the century, a reduced carbon sink is projected. This effect is due to a downregulation of photosynthesis rates, particularly in the tropical regions, even when accounting for CO2-fertilization effects. Altogether, the various global model simulations suggest the critical importance of including vegetation functional responses to changing environmental conditions to grasp terrestrial feedback mechanisms at global scales in the light of climate change.

Derivation of global vegetation biophysical parameters from EUMETSAT Polar System

NASA Astrophysics Data System (ADS)

García-Haro, Francisco Javier; Campos-Taberner, Manuel; Muñoz-Marí, Jordi; Laparra, Valero; Camacho, Fernando; Sánchez-Zapero, Jorge; Camps-Valls, Gustau

2018-05-01

This paper presents the algorithm developed in LSA-SAF (Satellite Application Facility for Land Surface Analysis) for the derivation of global vegetation parameters from the AVHRR (Advanced Very High Resolution Radiometer) sensor on board MetOp (Meteorological-Operational) satellites forming the EUMETSAT (European Organization for the Exploitation of Meteorological Satellites) Polar System (EPS). The suite of LSA-SAF EPS vegetation products includes the leaf area index (LAI), the fractional vegetation cover (FVC), and the fraction of absorbed photosynthetically active radiation (FAPAR). LAI, FAPAR, and FVC characterize the structure and the functioning of vegetation and are key parameters for a wide range of land-biosphere applications. The algorithm is based on a hybrid approach that blends the generalization capabilities offered by physical radiative transfer models with the accuracy and computational efficiency of machine learning methods. One major feature is the implementation of multi-output retrieval methods able to jointly and more consistently estimate all the biophysical parameters at the same time. We propose a multi-output Gaussian process regression (GPRmulti), which outperforms other considered methods over PROSAIL (coupling of PROSPECT and SAIL (Scattering by Arbitrary Inclined Leaves) radiative transfer models) EPS simulations. The global EPS products include uncertainty estimates taking into account the uncertainty captured by the retrieval method and input errors propagation. A sensitivity analysis is performed to assess several sources of uncertainties in retrievals and maximize the positive impact of modeling the noise in training simulations. The paper discusses initial validation studies and provides details about the characteristics and overall quality of the products, which can be of interest to assist the successful use of the data by a broad user's community. The consistent generation and distribution of the EPS vegetation products will

A nonlinear coupled soil moisture-vegetation model

NASA Astrophysics Data System (ADS)

Liu, Shikuo; Liu, Shida; Fu, Zuntao; Sun, Lan

2005-06-01

Based on the physical analysis that the soil moisture and vegetation depend mainly on the precipitation and evaporation as well as the growth, decay and consumption of vegetation a nonlinear dynamic coupled system of soil moisture-vegetation is established. Using this model, the stabilities of the steady states of vegetation are analyzed. This paper focuses on the research of the vegetation catastrophe point which represents the transition between aridness and wetness to a great extent. It is shown that the catastrophe point of steady states of vegetation depends mainly on the rainfall P and saturation value v0, which is selected to balance the growth and decay of vegetation. In addition, when the consumption of vegetation remains constant, the analytic solution of the vegetation equation is obtained.

Natural vegetation of Oregon and Washington.

Treesearch

Jerry F. Franklin; C.T. Dyrness

1973-01-01

Major vegetational units of Oregon and Washington and their environmental relationships are described and illustrated. After an initial consideration of the vegetation components in the two States, major geographic areas and vegetation zones are detailed. Descriptions of each vegetation zone include composition and succession, as well as discussion of variations...

A dataset mapping the potential biophysical effects of vegetation cover change

NASA Astrophysics Data System (ADS)

Duveiller, Gregory; Hooker, Josh; Cescatti, Alessandro

2018-02-01

Changing the vegetation cover of the Earth has impacts on the biophysical properties of the surface and ultimately on the local climate. Depending on the specific type of vegetation change and on the background climate, the resulting competing biophysical processes can have a net warming or cooling effect, which can further vary both spatially and seasonally. Due to uncertain climate impacts and the lack of robust observations, biophysical effects are not yet considered in land-based climate policies. Here we present a dataset based on satellite remote sensing observations that provides the potential changes i) of the full surface energy balance, ii) at global scale, and iii) for multiple vegetation transitions, as would now be required for the comprehensive evaluation of land based mitigation plans. We anticipate that this dataset will provide valuable information to benchmark Earth system models, to assess future scenarios of land cover change and to develop the monitoring, reporting and verification guidelines required for the implementation of mitigation plans that account for biophysical land processes.

A dataset mapping the potential biophysical effects of vegetation cover change

PubMed Central

Duveiller, Gregory; Hooker, Josh; Cescatti, Alessandro

2018-01-01

Changing the vegetation cover of the Earth has impacts on the biophysical properties of the surface and ultimately on the local climate. Depending on the specific type of vegetation change and on the background climate, the resulting competing biophysical processes can have a net warming or cooling effect, which can further vary both spatially and seasonally. Due to uncertain climate impacts and the lack of robust observations, biophysical effects are not yet considered in land-based climate policies. Here we present a dataset based on satellite remote sensing observations that provides the potential changes i) of the full surface energy balance, ii) at global scale, and iii) for multiple vegetation transitions, as would now be required for the comprehensive evaluation of land based mitigation plans. We anticipate that this dataset will provide valuable information to benchmark Earth system models, to assess future scenarios of land cover change and to develop the monitoring, reporting and verification guidelines required for the implementation of mitigation plans that account for biophysical land processes. PMID:29461538

Tertiary vegetation history

Treesearch

C. I. Millar

1996-01-01

The Tertiary period, from 2.5 to 65 million years ago, was the time oforigin of the modern Sierra Nevada landscape. Climates, geology,and vegetation changed drastically in the Sierra Nevada during thistime, and analyses of this period provide both context for and insightinto vegetation dynamics of the current and future Sierra. During theearly Tertiary, warm-humid,...

30-year Dynamics of Terrestrial Vegetation Activity and the Relationship with Climatologies

NASA Astrophysics Data System (ADS)

de Jong, R.; Schaepman, M. E.; Furrer, R.; de Bruin, S.; Verburg, P. H.

2013-12-01

The climate governs the seasonal activity of terrestrial vegetation while humankind influences it. The relative role of these drivers in changing vegetation activity is crucial information for accurate modeling of vegetation and climate dynamics and for adaptation and mitigation strategies. Disentangling the two, however, is an ongoing scientific challenge, because of limited data availability, mainly regarding non-climatic drivers, and complex biosphere-atmosphere feedback mechanisms. Here, we contribute to this quest by modeling the spatial relationship between climatologies and changes in global vegetation activity (de Jong et al., 2013a). Vegetation activity is commonly quantified using remotely sensed vegetation indices (VI). Extensive reports on temporal trends over the past decades in time series of such indices can be found in literature, including the detection of shifts (de Jong et al., 2013b), which may be related to climate (e.g. Zhao & Running, 2010). However, little remains known about the exact processes underlying vegetation change at large spatial scales. Depending on eco-region, three climatologies potentially constrain plant growth (Churkina and Running, 1998). In the humid mid-latitudes, for example, temperature is the largest influencing factor; in (semi) arid regions it is the availability of water and in the tropics incident solar radiation. Based on this logic, we developed a mixed-effect model to relate changes in these climatologies to changes in vegetation activity and to quantify the spatial process underlying the other drivers, including human land use. Little over 50% of the spatial variation in vegetation change could be attributed to changes in climatologies; conspicuously, many of the global ';greening' trends and the ';browning' hotspots in Argentina and Australia. Browning hotspots in the non-climatic component were especially located in subequatorial Africa (e.g. parts of Zimbabwe and Tanzania), where human drivers may be

Asynchronous vegetation phenology enhances winter body condition of a large mobile herbivore.

PubMed

Searle, Kate R; Rice, Mindy B; Anderson, Charles R; Bishop, Chad; Hobbs, N T

2015-10-01

Understanding how spatial and temporal heterogeneity influence ecological processes forms a central challenge in ecology. Individual responses to heterogeneity shape population dynamics, therefore understanding these responses is central to sustainable population management. Emerging evidence has shown that herbivores track heterogeneity in nutritional quality of vegetation by responding to phenological differences in plants. We quantified the benefits mule deer (Odocoileus hemionus) accrue from accessing habitats with asynchronous plant phenology in northwest Colorado over 3 years. Our analysis examined both the direct physiological and indirect environmental effects of weather and vegetation phenology on mule deer winter body condition. We identified several important effects of annual weather patterns and topographical variables on vegetation phenology in the home ranges of mule deer. Crucially, temporal patterns of vegetation phenology were linked with differences in body condition, with deer tending to show poorer body condition in areas with less asynchronous vegetation green-up and later vegetation onset. The direct physiological effect of previous winter precipitation on mule deer body condition was much less important than the indirect effect mediated by vegetation phenology. Additionally, the influence of vegetation phenology on body fat was much stronger than that of overall vegetation productivity. In summary, changing annual weather patterns, particularly in relation to seasonal precipitation, have the potential to alter body condition of this important ungulate species during the critical winter period. This finding highlights the importance of maintaining large contiguous areas of spatially and temporally variable resources to allow animals to compensate behaviourally for changing climate-driven resource patterns.

Vegetable Production System (Veggie)

NASA Technical Reports Server (NTRS)

Levine, Howard G.; Smith, Trent M.

2016-01-01

The Vegetable Production System (Veggie) was developed by Orbital Technologies Corp. to be a simple, easily stowed, and high growth volume yet low resource facility capable of producing fresh vegetables on the International Space Station (ISS). In addition to growing vegetables in space, Veggie can support a variety of experiments designed to determine how plants respond to microgravity, provide real-time psychological benefits for the crew, and conduct outreach activities. Currently, Veggie provides the largest volume available for plant growth on the ISS.

Predicting Changes in Arctic Tundra Vegetation: Towards an Understanding of Plant Trait Uncertainty

NASA Astrophysics Data System (ADS)

Euskirchen, E. S.; Serbin, S.; Carman, T.; Iversen, C. M.; Salmon, V.; Helene, G.; McGuire, A. D.

2017-12-01

Arctic tundra plant communities are currently undergoing unprecedented changes in both composition and distribution under a warming climate. Predicting how these dynamics may play out in the future is important since these vegetation shifts impact both biogeochemical and biogeophysical processes. More precise estimates of these future vegetation shifts is a key challenge due to both a scarcity of data with which to parameterize vegetation models, particularly in the Arctic, as well as a limited understanding of the importance of each of the model parameters and how they may vary over space and time. Here, we incorporate newly available field data from arctic Alaska into a dynamic vegetation model specifically developed to take into account a particularly wide array of plant species as well as the permafrost soils of the arctic tundra (the Terrestrial Ecosystem Model with Dynamic Vegetation and Dynamic Organic Soil, Terrestrial Ecosystem Model; DVM-DOS-TEM). We integrate the model within the Predicative Ecosystem Analyzer (PEcAn), an open-source integrated ecological bioinformatics toolbox that facilitates the flows of information into and out of process models and model-data integration. We use PEcAn to evaluate the plant functional traits that contribute most to model variability based on a sensitivity analysis. We perform this analysis for the dominant types of tundra in arctic Alaska, including heath, shrub, tussock and wet sedge tundra. The results from this analysis will help inform future data collection in arctic tundra and reduce model uncertainty, thereby improving our ability to simulate Arctic vegetation structure and function in response to global change.

Health Benefits of Fruits and Vegetables1

PubMed Central

Slavin, Joanne L.; Lloyd, Beate

2012-01-01

Fruits and vegetables are universally promoted as healthy. The Dietary Guidelines for Americans 2010 recommend you make one-half of your plate fruits and vegetables. Myplate.gov also supports that one-half the plate should be fruits and vegetables. Fruits and vegetables include a diverse group of plant foods that vary greatly in content of energy and nutrients. Additionally, fruits and vegetables supply dietary fiber, and fiber intake is linked to lower incidence of cardiovascular disease and obesity. Fruits and vegetables also supply vitamins and minerals to the diet and are sources of phytochemicals that function as antioxidants, phytoestrogens, and antiinflammatory agents and through other protective mechanisms. In this review, we describe the existing dietary guidance on intake of fruits and vegetables. We also review attempts to characterize fruits and vegetables into groups based on similar chemical structures and functions. Differences among fruits and vegetables in nutrient composition are detailed. We summarize the epidemiological and clinical studies on the health benefits of fruits and vegetables. Finally, we discuss the role of fiber in fruits and vegetables in disease prevention. PMID:22797986

Fruits and vegetables (image)

MedlinePlus

A healthy diet includes adding vegetables and fruit every day. Vegetables like broccoli, green beans, leafy greens, zucchini, cauliflower, cabbage, carrots, and tomatoes are low in calories and high in fiber, vitamins, and minerals. ...

Geomorphology and reflectance patterns of vegetation-covered dunes at the Tsodilo Hills, north-west Botswana

NASA Technical Reports Server (NTRS)

Jacobberger, P. A.; Hooper, D. M.

1991-01-01

Seasonal reflectance variations in semigrid environments provide a means of assessing vegetation health and density as well as monitoring landform processes. Multitemporal Landsat Thematic Mapper scenes with field measurements are used to map geomorphology and vegetation density in a stabilized dune environment and to measure seasonal reflectance changes for a series of ten geomorphological and vegetation units on the Kalahari-age linear dunes. Units were chosen based on differences in landform and proportion of trees, forbs and bare soil. Reflectance curves and normalized-difference vegetation indices (NDVI) show that dune crests have the strongest seasonal variability in color and brightness. The geomorphological link with reflectance and NDVI values are linked to biomass production and zoning of vegetation with slope, drainage and subtle soil differences.

Analysis of Post-Fire Vegetation Recovery in the Mediterranean Basin using MODIS Derived Vegetation Indices

NASA Astrophysics Data System (ADS)

Hawtree, Daniel; San Miguel, Jesus; Sedano, Fernando; Kempeneers, Pieter

2010-05-01

The Mediterranean basin region is highly susceptible to wildfire, with approximately 60,000 individual fires and half a million ha of natural vegetation burnt per year. Of particular concern in this region is the impact of repeated wildfires on the ability of natural lands to return to a pre-fire state, and of the possibility of desertification of semi-arid areas. Given these concerns, understanding the temporal patterns of vegetation recovery is important for the management of environmental resources in the region. A valuable tool for evaluating these recovery patterns are vegetation indices derived from remote sensing data. Previous research on post-fire vegetation recovery conducted in this region has found significant variability in recovery times across different study sites. It is unclear what the primary variables are affecting the differences in the rates of recovery, and if any geographic patterns of behavior exist across the Mediterranean basin. This research has primarily been conducted using indices derived from Landsat imagery. However, no extensive analysis of vegetation regeneration for large regions has been published, and assessment of vegetation recovery on the basis of medium-spatial resolution imagery such as that of MODIS has not yet been analyzed. This study examines the temporal pattern of vegetation recovery in a number of fire sites in the Mediterranean basin, using data derived from MODIS 16 -day composite vegetation indices. The intent is to develop a more complete picture of the temporal sequence of vegetation recovery, and to evaluate what additional factors impact variations in the recovery sequence. In addition, this study evaluates the utility of using MODIS derived vegetation indices for regeneration studies, and compares the findings to earlier studies which rely on Landsat data. Wildfires occurring between the years 2000 and 2004 were considered as potential study sites for this research. Using the EFFIS dataset, all wildfires

Prevalence and counts of Salmonella spp. in minimally processed vegetables in São Paulo, Brazil.

PubMed

Sant'Ana, Anderson S; Landgraf, Mariza; Destro, Maria Teresa; Franco, Bernadette D G M

2011-09-01

Minimally processed vegetables (MPV) may be important vehicles of Salmonella spp. and cause disease. This study aimed at detecting and enumerating Salmonella spp. in MPV marketed in the city of São Paulo, Brazil. A total of 512 samples of MPV packages collected in retail stores were tested for Salmonella spp. and total coliforms and Escherichia coli as indication of the hygienic status. Salmonella spp. was detected in four samples, two using the detection method and two using the counting method, where the results were 8.8 × 10(2) CFU/g and 2.4 × 10(2) CFU/g. The serovars were Salmonella Typhimurium (three samples) and Salmonella enterica subsp. enterica O:47:z4,z23:- (one sample). Fourteen samples (2.7%) presented counts of E. coli above the maximum limit established by the Brazilian regulation for MPV (10(2) CFU/g). Therefore, tightened surveillance and effective intervention strategies are necessary in order to address consumers and governments concerns on safety of MPV. Copyright © 2011 Elsevier Ltd. All rights reserved.

Occurrence of rhodamine B contamination in capsicum caused by agricultural materials during the vegetation process.

PubMed

Gao, Wei; Wu, Naiying; Du, Jingjing; Zhou, Li; Lian, Yunhe; Wang, Lei; Liu, Dengshuai

2016-08-15

This paper reports on the environmental rhodamine B (RhB) contamination in capsicum caused by agricultural materials during the vegetation process. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was applied to detect 64 capsicum samples from China, Peru, India and Burma. Results demonstrated that RhB was found in all samples at low concentrations (0.11-0.98 μg/kg), indicating RhB contamination in capsicums is probably a ubiquitous phenomenon. In addition, studies into soils, roots, stems and leaves in Handan of Hebei province, China showed that the whole ecologic chain had been contaminated with RhB with the highest levels in leaves. The investigation into the agricultural environment in Handan of Hebei province and Korla of Xinjiang province, China demonstrated that the appearances of RhB contamination in the tested capsicums are mainly due to the agricultural materials contamination. The study verified that environmental contamination should be an important origin for the RhB contamination in capsicum fruits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Riparian rehabilitation using vegetation patches: field and laboratory investigations linking hydrology, vegetation and geomorphology

NASA Astrophysics Data System (ADS)

Rodriguez, J. F.; Gorrick, S.

2010-12-01

We present results of a riparian revegetation project on an oversized sand stream in eastern Australia. The Widden Brook in New South Wales has undergone extensive widening due to extraordinary floods in the 1950’s and is currently showing some signs of recovery. These include emergence of pool-riffle structure and stabilization of stream width, which are the result of upstream sediment control, riparian revegetation and livestock exclusion. Revegetation of a mild bend was carried out in 2004 using native plants in an arrangement that consisted of three vegetation patches. The same arrangement was tested in a reduced scale model in the laboratory, where extensive measurements of flow, sediment and bed changes provided insight into the links between hydrology, vegetation and geomorphology. Laboratory tests also included runs without vegetation and with a continuous vegetation cover. In terms of bank stability, the patches provided as much protection as the continuous vegetation. Based on the experiments, a series of analytical relationships were developed to help guide the design of vegetation patches focusing on the geomorphic stability of the whole reach instead of concentrating only on the near bank effects.

Recommendations for Constructing Roadside Vegetation ...

EPA Pesticide Factsheets

Recommendations for external partners planting roadside vegetation. Intended for broad use, but immediate use will be to provide to project partners on the RESES roadside vegetation project and as an attachment to the RESES project QAPP Provide recommendations on the physical characteristics of roadside vegetation that can provide a local air quality benefit

Groundwater Controls on Vegetation Composition and Patterning in Mountain Meadows

NASA Astrophysics Data System (ADS)

Loheide, S. P.; Lowry, C.; Moore, C. E.; Lundquist, J. D.

2010-12-01

Mountain meadows are groundwater dependent ecosystems that are hotspots of biodiversity and productivity in the Sierra Nevada of California. Meadow vegetation relies on shallow groundwater during the region’s dry summer growing season. Vegetation composition in this environment is influenced both by 1) oxygen stress that occurs when portions of the root zone are saturated and anaerobic conditions are created that limit root respiration and 2) water stress that occurs when the water table drops and water-limited conditions are created in the root zone. A watershed model that explicitly accounts for snowmelt processes was linked to a fine resolution groundwater flow model of Tuolumne Meadows in Yosemite National Park, CA to simulated spatially distributed water table dynamics. This linked hydrologic model was calibrated to observations from a well observation network for 2006-2008, and validated using data from 2009. A vegetation survey was also conducted at the site in which the three dominant species were identified at more than 200 plots distributed across the meadow. Nonparametric multiplicative regression was performed to create and select the best models for predicting vegetation dominance based on simulated hydrologic regime. The hydrologic niche of three vegetation types representing wet, moist, and dry meadow vegetation communities was best described using both 1) a sum exceedance value calculated as the integral of water table position above a threshold of oxygen stress and 2) a sum deceedance value calculated as the integral of water table position below a threshold of water stress. This linked hydrologic and vegetative modeling framework advances our ability to predict the propagation of human-induced climatic and land-use/-cover changes through the hydrologic system to the ecosystem.

Vegetation-Associated Impacts on Arctic Tundra Bacterial and Microeukaryotic Communities

PubMed Central

Shi, Yu; Xiang, Xingjia; Shen, Congcong; Neufeld, Josh D.; Walker, Virginia K.

2014-01-01

The Arctic is experiencing rapid vegetation changes, such as shrub and tree line expansion, due to climate warming, as well as increased wetland variability due to hydrological changes associated with permafrost thawing. These changes are of global concern because changes in vegetation may increase tundra soil biogeochemical processes that would significantly enhance atmospheric CO2 concentrations. Predicting the latter will at least partly depend on knowing the structure, functional activities, and distributions of soil microbes among the vegetation types across Arctic landscapes. Here we investigated the bacterial and microeukaryotic community structures in soils from the four principal low Arctic tundra vegetation types: wet sedge, birch hummock, tall birch, and dry heath. Sequencing of rRNA gene fragments indicated that the wet sedge and tall birch communities differed significantly from each other and from those associated with the other two dominant vegetation types. Distinct microbial communities were associated with soil pH, ammonium concentration, carbon/nitrogen (C/N) ratio, and moisture content. In soils with similar moisture contents and pHs (excluding wet sedge), bacterial, fungal, and total eukaryotic communities were correlated with the ammonium concentration, dissolved organic nitrogen (DON) content, and C/N ratio. Operational taxonomic unit (OTU) richness, Faith's phylogenetic diversity, and the Shannon species-level index (H′) were generally lower in the tall birch soil than in soil from the other vegetation types, with pH being strongly correlated with bacterial richness and Faith's phylogenetic diversity. Together, these results suggest that Arctic soil feedback responses to climate change will be vegetation specific not just because of distinctive substrates and environmental characteristics but also, potentially, because of inherent differences in microbial community structure. PMID:25362064

A Review of the Anaerobic Digestion of Fruit and Vegetable Waste.

PubMed

Ji, Chao; Kong, Chui-Xue; Mei, Zi-Li; Li, Jiang

2017-11-01

Fruit and vegetable waste is an ever-growing global question. Anaerobic digestion techniques have been developed that facilitate turning such waste into possible sources for energy and fertilizer, simultaneously helping to reduce environmental pollution. However, various problems are encountered in applying these techniques. The purpose of this study is to review local and overseas studies, which focus on the use of anaerobic digestion to dispose fruit and vegetable wastes, discuss the acidification problems and solutions in applying anaerobic digestion for fruit and vegetable wastes and investigate the reactor design (comparing single phase with two phase) and the thermal pre-treatment for processing raw wastes. Furthermore, it analyses the dominant microorganisms involved at different stages of digestion and suggests a focus for future studies.

Seasonal changes in quality of wastewater from fruit and vegetable industry

NASA Astrophysics Data System (ADS)

Puchlik, Monika; Ignatowicz, Katarzyna

2017-11-01

The paper aimed at evaluating the seasonal changes in quality of wastewater from facilities producing fruit and vegetable juices, processed and frozen products, and vegetable concentrates. The study revealed that wastewater from fruit and vegetable industry contain large amounts of organic substances expressed as BOD5 (minimum - 500 mgO2/dm3, maximum - 6 100 mgO2/dm3) and COD (minimum - 806 mg O2/dm3, maximum - 7 732 mg O2/dm3), while is deficient in nitrogen and phosphorus. Considerable seasonal oscillations in sewage load disposed by industry to sewerage, were observed. An increase of 50%-60% wastewater concentrations was found between June and October in 2013-2016 as compared to the remaining months.

Remote sensing of vegetation pattern and condition to monitor changes in Everglades biogeochemistry

USGS Publications Warehouse

Jones, John W.

2011-01-01

Ground-based studies of biogeochemistry and vegetation patterning yield process understanding, but the amount of information gained by ground-based studies can be greatly enhanced by efficient, synoptic, and temporally resolute monitoring afforded by remote sensing. The variety of presently available Everglades vegetation maps reflects both the wide range of application requirements and the need to balance cost and capability. More effort needs to be applied to documenting and understanding vegetation distribution and condition as indicators of biogeochemistry and contamination. Ground-based and remote sensing studies should be modified to maximize their synergy and utility for adaptive management.

Role of vegetation in modulating denudation and topography across the Himalaya

NASA Astrophysics Data System (ADS)

Olen, Stephanie; Bookhagen, Bodo; Strecker, Manfred

2015-04-01

Studies of Himalayan denudation, to date, have primarily focused on the effects of lithology, tectonic activity, and climate in shaping landscape and controlling denudation rates. Climate can impact denudation not only through increased precipitation, runoff, or glaciation, but also via its role in controlling vegetation cover. Since the classical study of Langbein and Schumm [1958] emphasizing the role of vegetation cover in determining erosional efficiency, theoretical and plot-scale studies have highlighted the role of vegetation on surface processes [Collins et al., 2004; Istanbulluoglu and Bras, 2005; Collins and Bras, 2010; Carretier et al., 2013; Jeffery et al., 2014]. Vegetation cover and density vary considerably in the Himalaya, both across and along strike. Across strike, vegetation transitions from dense forest and agriculturally-used plots in the Lesser Himalaya to sparse alpine and arid, virtually non-vegetated regions at high elevation and in the rain shadow north of the Higher Himalaya peaks. Along-strike vegetation densities also differ significantly and show a pronounced E-W gradient. To quantify the along-strike vegetation gradient, we use 14 years of MODIS 13C1 enhanced vegetation index (EVI) data to calculate mean annual, summer (MJJASO), and winter (NDJFMA) for the entire Himalaya. Additionally, we calculate a differential EVI that compares summer versus winter vegetation density (MJJASO/NDJFMA). A decrease in vegetation density is observed from east to west, with the greatest difference in winter vegetation cover (225% higher in the eastern than western Himalaya). In contrast, differential EVI is higher in the western Himalaya, increasing 170% from east to west. To evaluate the effect of vegetation on denudation and landscape evolution, we combine the 14-year EVI data, topographic analysis, and a compilation of >100 published and unpublished 10-Be terrestrial cosmogenic nuclide (TCN) catchment-mean denudation rates from across the Himalaya

White Vegetables: Glycemia and Satiety12

PubMed Central

Anderson, G. Harvey; Soeandy, Chesarahmia Dojo; Smith, Christopher E.

2013-01-01

The objective of this review is to discuss the effect of white vegetable consumption on glycemia, satiety, and food intake. White vegetables is a term used to refer to vegetables that are white or near white in color and include potatoes, cauliflowers, turnips, onions, parsnips, white corn, kohlrabi, and mushrooms (technically fungi but generally considered a vegetable). They vary greatly in their contribution to the energy and nutrient content of the diet and glycemia and satiety. As with other foods, the glycemic effect of many white vegetables has been measured. The results illustrate that interpretation of the semiquantitative comparative ratings of white vegetables as derived by the glycemic index must be context dependent. As illustrated by using the potato as an example, the glycemic index of white vegetables can be misleading if not interpreted in the context of the overall contribution that the white vegetable makes to the carbohydrate and nutrient composition of the diet and their functionality in satiety and metabolic control within usual meals. It is concluded that application of the glycemic index in isolation to judge the role of white vegetables in the diet and, specifically in the case of potato as consumed in ad libitum meals, has led to premature and possibly counterproductive dietary guidance. PMID:23674805

Retronasal olfaction in vegetable liking and disliking.

PubMed

Lim, Juyun; Padmanabhan, Arthi

2013-01-01

While previous research has suggested that bitterness is a key determinant of vegetable rejection, it is unknown what role odor may play. We therefore investigated the impact of retronasal odors on hedonic responses to 4 vegetables. Subjects (N = 132) tasted small samples with the nose open and closed and rated the degree of liking/disliking, as well as the perceived intensity of sweetness, bitterness, saltiness, and vegetable flavor. The subjects were classified as "likers" or "dislikers" of each vegetable. The degree to which "likers" liked and "dislikers" disliked the vegetables was significantly less in the nose-closed condition, indicating that retronasal odor was a significant driver of vegetable hedonics. In contrast, bitterness ratings for all 4 vegetables did not differ significantly between the groups. The perceived intensity of vegetable flavor also did not differ significantly between groups, implying that the quality of vegetable odors rather than their perceived intensity drove the hedonic ratings. In a follow-up experiment, returning subjects (N = 89) rated the degree of liking/disliking of the vegetable odors alone, which were presented retronasally. Liking/disliking of specific odors was positively correlated with that for the sampled vegetables across all stimuli (r = 0.32~0.57). Overall, these results suggest that retronasal odor plays an important role in vegetable liking/disliking.

Discoloration of Indigo Carmine Using Aqueous Extracts from Vegetables and Vegetable Residues as Enzyme Sources

PubMed Central

Solís, A.; Perea, F.; Solís, M.; Manjarrez, N.; Pérez, H. I.; Cassani, J.

2013-01-01

Several vegetables and vegetable residues were used as sources of enzymes capable to discolor indigo carmine (IC), completely or partially. Complete discoloration was achieved with aqueous extracts of green pea seeds and peels of green pea, cucumber, and kohlrabi, as well as spring onion leaves. The source of polyphenol oxidase (PPO), pH, time, and aeration is fundamental for the discoloration process catalyzed by PPO. The PPO present in the aqueous extract of green pea seeds was able to degrade 3,000 ppm of IC at a pH of 7.6 and magnetic stirring at 1,800 rpm in about 36 h. In addition, at 1,800 rpm and a pH of 7.6, this extract discolored 300 ppm of IC in 1:40 h; in the presence of 10% NaCl, the discoloration was complete in 5:50 h, whereas it was completed in 4:30 h with 5% NaCl and 2% laundry soap. PMID:24151588

Ecology of bison, elk, and vegetation in an arid ecosystem

USGS Publications Warehouse

Schoenecker, Kathryn A.

2012-01-01

Herbivory has profound effects on vegetation production and structure in many different plant communities. The influence of herbivory on plants and ultimately ecosystem processes is shaped by the types of plants consumed, the intensity of herbivory, the evolutionary history of grazing, and the availability of water and nutrients to plants. The effect of ungulate herbivores on vegetation is of great interest to ecologists, land managers and agriculturalists. In addition, the Department of Interior recently established a Bison Conservation Initiative to provide for the conservation and restoration of North American plains- and wood bison, which includes establishing new populations and expanding existing populations. The San Luis Valley, Colorado, is being considered as a potential location for a bison conservation herd. Resource managers need to know the vegetation impacts of adding a second large ungulate to a system that already has elk.

A vital link: water and vegetation in the Anthropocene

NASA Astrophysics Data System (ADS)

Gerten, D.

2013-04-01

This paper argues that the interplay of water, carbon and vegetation dynamics is fundamental to some global trends in the current and conceivable future Anthropocene. Supported by simulations with a process-based biosphere model and a literature review, it demonstrates that the connectivity of freshwater and vegetation dynamics is vital for water security, food security and (terrestrial) ecosystem integrity alike. The water limitation of net primary production of both natural and agricultural plants - already pronounced in many regions - is shown to increase in many places under projected climate change, though this development is partially offset by water-saving direct CO2 effects. Natural vegetation can to some degree adapt dynamically to higher water limitation, but agricultural crops require some form of active management to overcome it - among them irrigation, soil conservation and expansion into still uncultivated areas. While crucial to secure food production for a growing world population, such human interventions in water-vegetation systems have, as also shown, repercussions to the water cycle. Indeed, land use changes have been shown to be the second-most important influence on the terrestrial water balance in recent times. Furthermore, climate change regionally increases irrigation demand and decreases freshwater availability, impeding on rainfed and irrigated food production (if not CO2 effects counterbalance this impact - which is unlikely at least in poorly managed systems). Drawing from these exemplary investigations, some research perspectives on how to further improve our quantitative knowledge of human-water-vegetation interactions in the Anthropocene are outlined.

Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables

PubMed Central

Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman‐Novakofski, Karen; Phillips, Carter

2018-01-01

Abstract Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P < 0.001), indicating the sensory properties were significantly improved with seasoning. When general vegetable likers and specific vegetable likers were compared in terms of their preference between seasoned and unseasoned vegetables, the pattern varied across different vegetables; however, general trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. Practical Application To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. PMID:29337353

Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables.

PubMed

Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman-Novakofski, Karen; Phillips, Carter; Lee, Soo-Yeun

2018-02-01

Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P < 0.001), indicating the sensory properties were significantly improved with seasoning. When general vegetable likers and specific vegetable likers were compared in terms of their preference between seasoned and unseasoned vegetables, the pattern varied across different vegetables; however, general trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. © 2018 The Authors Journal of Food Science published by Wiley Periodicals, Inc

Geomorphic and vegetation processes of the Willamette River floodplain, Oregon: current understanding and unanswered science questions

USGS Publications Warehouse

Wallick, J. Rose; Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Hulse, David; Gregory, Stanley V.

2013-01-01

4. How is the succession of native floodplain vegetation shaped by present-day flow and sediment conditions? Answering these questions will produce baseline data on the current distributions of landforms and habitats (question 1), the extent of the functional floodplain (question 2), and the effects of modern flow and sediment regimes on future floodplain landforms, habitats, and vegetation succession (questions 3 and 4). Addressing questions 1 and 2 is a logical next step because they underlie questions 3 and 4. Addressing these four questions would better characterize the modern Willamette Basin and help in implementing and setting realistic targets for ongoing management strategies, demonstrating their effectiveness at the site and basin scales, and anticipating future trends and conditions.

Study on biomethane production and biodegradability of different leafy vegetables in anaerobic digestion.

PubMed

Yan, Hu; Zhao, Chen; Zhang, Jiafu; Zhang, Ruihong; Xue, Chunyu; Liu, Guangqing; Chen, Chang

2017-12-01

Enormous amounts of vegetable residues are wasted annually, causing many environmental problems due to their high moisture and organic contents. In this study, the methane production potential of 20 kinds of typical leafy vegetable residues in China were explored using a unified method. A connection between the biochemical components and the methane yields of these vegetables was well established which could be used to predict biogas performance in practice. A high volatile solid/total solid (VS/TS) ratio and hemicellulose content exhibited a positive impact on the biogas yield while lignin had a negative impact. In addition, three kinetic models were used to describe the methane production process of these agro-wastes. The systematic comparison of the methane production potentials of these leafy vegetables shown in this study will not only serve as a reference for basic research on anaerobic digestion but also provide useful data and information for agro-industrial applications of vegetable residues in future work.

A novel approach for modelling vegetation distributions and analysing vegetation sensitivity through trait-climate relationships in China

PubMed Central

Yang, Yanzheng; Zhu, Qiuan; Peng, Changhui; Wang, Han; Xue, Wei; Lin, Guanghui; Wen, Zhongming; Chang, Jie; Wang, Meng; Liu, Guobin; Li, Shiqing

2016-01-01

Increasing evidence indicates that current dynamic global vegetation models (DGVMs) have suffered from insufficient realism and are difficult to improve, particularly because they are built on plant functional type (PFT) schemes. Therefore, new approaches, such as plant trait-based methods, are urgently needed to replace PFT schemes when predicting the distribution of vegetation and investigating vegetation sensitivity. As an important direction towards constructing next-generation DGVMs based on plant functional traits, we propose a novel approach for modelling vegetation distributions and analysing vegetation sensitivity through trait-climate relationships in China. The results demonstrated that a Gaussian mixture model (GMM) trained with a LMA-Nmass-LAI data combination yielded an accuracy of 72.82% in simulating vegetation distribution, providing more detailed parameter information regarding community structures and ecosystem functions. The new approach also performed well in analyses of vegetation sensitivity to different climatic scenarios. Although the trait-climate relationship is not the only candidate useful for predicting vegetation distributions and analysing climatic sensitivity, it sheds new light on the development of next-generation trait-based DGVMs. PMID:27052108

The impact of biopreservatives and storage temperature in the quality and safety of minimally processed mixed vegetables for soup.

PubMed

Alvarez, María V; Ponce, Alejandra G; Mazzucotelli, Cintia A; Moreira, María R

2015-03-30

The combined effects of bioactive agents (tea tree essential oil, propolis extract and gallic acid) and storage temperature on the microbiological and sensory quality of fresh-cut mixed vegetables for soup (celery, leek and butternut squash) were studied with the objective of preserving its quality and safety. Refrigeration temperature was confirmed as the main factor to limit the growth of spoilage and pathogenic microorganisms. Biopreservatives applied on mixed vegetables were effective only when combined with optimal refrigeration temperature (5 °C). Bioactive compounds showed slight effectiveness in controlling the microbiota present in mixed vegetables, although coliforms were greatly reduced by gallic acid and propolis treatments, achieving 0.5-2 log unit reductions during storage. Also, these agents showed antimicrobial activity against endogenous Escherichia coli and inoculated E. coli O157:H7, exerting a bacteriostatic effect and reducing population counts by 0.9-1.2 log CFU g(-1) at 10 days of refrigerated storage. The combination of propolis treatment with refrigerated storage conditions effectively preserved the sensory quality and prolonged the sensory shelf life of fresh-cut mixed vegetables by 3 days. The use of natural agents such as propolis extract to preserve the quality and safety of mixed vegetables for soup might be an interesting option to address the concerns of the consumer about the use of synthetic chemical antimicrobials potentially harmful to health. © 2014 Society of Chemical Industry.

Predicting gender differences in liking for vegetables and preference for a variety of vegetables among 11-year-old children.

PubMed

Lehto, Elviira; Ray, Carola; Haukkala, Ari; Yngve, Agneta; Thorsdottir, Inga; Roos, Eva

2015-12-01

We studied the factors that predict liking for vegetables and preference for a variety of vegetables among schoolchildren. Additionally, we examined if there were gender differences in the predictors that explain the hypothesized higher scores in liking vegetables and preferences among girls. The data from the PRO GREENS project included 424 Finnish children (response rate 77%) aged 11 to 12. The children completed validated measures about social and environmental factors related to their liking for vegetables and preferences both at baseline 2009 and follow-up 2010. The associations were examined with regression and mediation analyses. The strongest predictors of both girls' and boys' liking and preferences were higher levels of eating vegetables together with the family, previous vegetable intake and a lower level of perceived barriers. Liking was additionally predicted by a lower level of parental demand that their child should eat vegetables. Girls reported higher levels of liking and preferences in the follow-up. This gender difference was mainly explained by girls' lower level of perceived barriers related to vegetable intake and girls' higher previous vegetable intake. Interventions that aim to increase the low vegetable intake among boys by increasing their liking for vegetables and preference for a variety of vegetables could benefit from targeting perceived barriers, namely boys' perception and values concerning the consumption of vegetables. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia

USGS Publications Warehouse

Tang, Guoping; Shafer, Sarah L.; Barlein, Patrick J.; Holman, Justin O.

2009-01-01

Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating the model results, and (iii) the methods used to compare simulated and observed vegetation. We use vegetation simulated for Asia by the equilibrium vegetation model BIOME4 as a typical example of vegetation model output. BIOME4 was run using 19 different climatologies and their associated atmospheric CO2 concentrations. The Kappa statistic, Fuzzy Kappa statistic and a newly developed map-comparison method, the Nomad index, were used to quantify the agreement between the biomes simulated under each scenario and the observed vegetation from three different global land- and tree-cover data sets: the global Potential Natural Vegetation data set (PNV), the Global Land Cover Characteristics data set (GLCC), and the Global Land Cover Facility data set (GLCF). The results indicate that the 30-year mean climatology (and its associated atmospheric CO2 concentration) for the time period immediately preceding the collection date of the observed vegetation data produce the most accurate vegetation simulations when compared with all three observed vegetation data sets. The study also indicates that the BIOME4-simulated vegetation for Asia more closely matches the PNV data than the other two observed vegetation data sets. Given the same observed data, the accuracy assessments of the BIOME4 simulations made using the Kappa, Fuzzy Kappa and Nomad index map-comparison methods agree well when the compared vegetation types consist of a large number of spatially continuous grid cells. The results of this analysis can assist model users in designing experimental protocols for simulating vegetation.

Consumer attitudes towards vegetable attributes: potential buyers of pesticide-free vegetables in Accra and Kumasi, Ghana.

PubMed

Probst, Lorenz; Aigelsperger, Lisa; Hauser, Michael

2010-01-01

Considering the inappropriate use of synthetic pesticides on vegetables in West Africa, the rationale behind this research was to assess the extent to which consumers can function as demanders of risk reduced vegetables and hence act as innovators towards vegetable safety. Using the cases of Kumasi and Accra in Ghana, the study examined possible consumer responses to product certification that communicates freedom from pesticides (e.g., organic certification). Generally, search attributes such as the fresh and healthy appearance of a vegetable were found to be central to consumer choice. While consumers stress the importance of health value, they are mostly unaware of agro-chemical risks related to vegetable consumption.

Modified atmosphere packaging for fresh-cut fruits and vegetables

USDA-ARS?s Scientific Manuscript database

The latest development in and different aspects of modified atmosphere packaging for fresh-cut fruits and vegetables are reviewed in the book. This book provides all readers, including fresh-cut academic researchers, fresh-cut R&D personnel, and fresh-cut processing engineers, with unique, essential...

Assessing vegetation structure and ANPP dynamics in a grassland-shrubland Chihuahuan ecotone using NDVI-rainfall relationships

NASA Astrophysics Data System (ADS)

Moreno-de las Heras, M.; Diaz-Sierra, R.; Turnbull, L.; Wainwright, J.

2015-01-01

Climate change and the widespread alteration of natural habitats are major drivers of vegetation change in drylands. A classic case of vegetation change is the shrub-encroachment process that has been taking place over the last 150 years in the Chihuahuan Desert, where large areas of grasslands dominated by perennial grass species (black grama, Bouteloua eriopoda, and blue grama, B. gracilis) have transitioned to shrublands dominated by woody species (creosotebush, Larrea tridentata, and mesquite, Prosopis glandulosa), accompanied by accelerated water and wind erosion. Multiple mechanisms drive the shrub-encroachment process, including exogenous triggering factors such as precipitation variations and land-use change, and endogenous amplifying mechanisms brought about by soil erosion-vegetation feedbacks. In this study, simulations of plant biomass dynamics with a simple modelling framework indicate that herbaceous (grasses and forbs) and shrub vegetation in drylands have different responses to antecedent precipitation due to functional differences in plant growth and water-use patterns, and therefore shrub encroachment may be reflected in the analysis of landscape-scale vegetation-rainfall relationships. We analyze the structure and dynamics of vegetation at an 18 km2 grassland-shrubland ecotone in the northern edge of the Chihuahuan Desert (McKenzie Flats, Sevilleta National Wildlife Refuge, NM, USA) by investigating the relationship between decade-scale (2000-2013) records of medium-resolution remote sensing of vegetation greenness (MODIS NDVI) and precipitation. Spatial evaluation of NDVI-rainfall relationship at the studied ecotone indicates that herbaceous vegetation shows quick growth pulses associated with short-term (previous 2 months) precipitation, while shrubs show a slow response to medium-term (previous 5 months) precipitation. We use these relationships to (a) classify landscape types as a function of the spatial distribution of dominant vegetation

On the use of satellite VEGETATION time series for monitoring post fire vegetation recovery

NASA Astrophysics Data System (ADS)

de Santis, F.; Didonna, I.

2009-04-01

Fire is one of the most critical factors of disturbance in worldwide ecosystems. The effects of fires on soil, plants, landscape and ecosystems depend on many factors, among them fire frequency, fire severity and plant resistance. The characterization of vegetation post-fire behaviour is a fundamental issue to model and evaluate the fire resilience, which the ability of vegetation to recover after fire. Recent changes in fire regime, due to abandonment of local land use practice and climate change, can induce significant variations in vegetation fire resilience. In the Mediterranean-type communities, post fire vegetation trends have been analysed in a wide range of habitats, although pre- and post-fire investigation has been widely performed at stand level. But, factors controlling regeneration at the landscape scale are less well known. In this study, a time series of normalized difference vegetation index (NDVI) data derived from SPOT-VEGETATION was used to examine the recovery characteristics of fire affected vegetation in some test areas of the Mediterranean ecosystems of Southern Italy. The vegetation indices operate by contrasting intense chlorophyll pigment absorption in the red against the high reflectance of leaf mesophyll in the near infrared. SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) data from 1998 to 2005 were analyzed in order to evaluate the resilient effects in a some significant test sites of southern Italy. In particular, we considered: (i) one stable area site, one site affected by one fire during the investigated time window, (iii) one site affected by two consecutive fires during the investigated time window. In order to eliminate the phenological fluctuations, for each decadal composition of each pixel, we focused on the departure NDVId = [NDVI - ]/, where is the decadal mean and  is the decadal standard deviation. The decadal mean and the standard deviation were calculated for each decade, e.g. 1st

CRMS vegetation analytical team framework: Methods for collection, development, and use of vegetation response variables

USGS Publications Warehouse

Cretini, Kari F.; Visser, Jenneke M.; Krauss, Ken W.; Steyer, Gregory D.

2011-01-01

This document identifies the main objectives of the Coastwide Reference Monitoring System (CRMS) vegetation analytical team, which are to provide (1) collection and development methods for vegetation response variables and (2) the ways in which these response variables will be used to evaluate restoration project effectiveness. The vegetation parameters (that is, response variables) collected in CRMS and other coastal restoration projects funded under the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) are identified, and the field collection methods for these parameters are summarized. Existing knowledge on community and plant responses to changes in environmental drivers (for example, flooding and salinity) from published literature and from the CRMS and CWPPRA monitoring dataset are used to develop a suite of indices to assess wetland condition in coastal Louisiana. Two indices, the floristic quality index (FQI) and a productivity index, are described for herbaceous and forested vegetation. The FQI for herbaceous vegetation is tested with a long-term dataset from a CWPPRA marsh creation project. Example graphics for this index are provided and discussed. The other indices, an FQI for forest vegetation (that is, trees and shrubs) and productivity indices for herbaceous and forest vegetation, are proposed but not tested. New response variables may be added or current response variables removed as data become available and as our understanding of restoration success indicators develops. Once indices are fully developed, each will be used by the vegetation analytical team to assess and evaluate CRMS/CWPPRA project and program effectiveness. The vegetation analytical teams plan to summarize their results in the form of written reports and/or graphics and present these items to CRMS Federal and State sponsors, restoration project managers, landowners, and other data users for their input.

Remote-Sensing Time Series Analysis, a Vegetation Monitoring Tool

NASA Technical Reports Server (NTRS)

McKellip, Rodney; Prados, Donald; Ryan, Robert; Ross, Kenton; Spruce, Joseph; Gasser, Gerald; Greer, Randall

2008-01-01

The Time Series Product Tool (TSPT) is software, developed in MATLAB , which creates and displays high signal-to- noise Vegetation Indices imagery and other higher-level products derived from remotely sensed data. This tool enables automated, rapid, large-scale regional surveillance of crops, forests, and other vegetation. TSPT temporally processes high-revisit-rate satellite imagery produced by the Moderate Resolution Imaging Spectroradiometer (MODIS) and by other remote-sensing systems. Although MODIS imagery is acquired daily, cloudiness and other sources of noise can greatly reduce the effective temporal resolution. To improve cloud statistics, the TSPT combines MODIS data from multiple satellites (Aqua and Terra). The TSPT produces MODIS products as single time-frame and multitemporal change images, as time-series plots at a selected location, or as temporally processed image videos. Using the TSPT program, MODIS metadata is used to remove and/or correct bad and suspect data. Bad pixel removal, multiple satellite data fusion, and temporal processing techniques create high-quality plots and animated image video sequences that depict changes in vegetation greenness. This tool provides several temporal processing options not found in other comparable imaging software tools. Because the framework to generate and use other algorithms is established, small modifications to this tool will enable the use of a large range of remotely sensed data types. An effective remote-sensing crop monitoring system must be able to detect subtle changes in plant health in the earliest stages, before the effects of a disease outbreak or other adverse environmental conditions can become widespread and devastating. The integration of the time series analysis tool with ground-based information, soil types, crop types, meteorological data, and crop growth models in a Geographic Information System, could provide the foundation for a large-area crop-surveillance system that could identify

When Fruits and Vegetables Are Optional, Elementary School Children Choose Processed over Whole Offerings

ERIC Educational Resources Information Center

Amin, Sarah A.; Yon, Bethany A.; Taylor, Jennifer C.; Johnson, Rachel K.

2014-01-01

Purpose/Objectives: Increasing children's fruit and vegetable (FV) consumption is an important goal for the National School Lunch Program (NSLP). In 2012 the NSLP began requiring students to select a FV. The objective of this study was to compare children's FV choices in two school cafeteria environments a year before these new USDA regulations…

Developing a global mixed-canopy, height-variable vegetation structure dataset for estimating global vegetation albedo and biomass in the NASA Ent Terrestrial Biosphere Model and GISS GCM

NASA Astrophysics Data System (ADS)

Montes, C.; Kiang, N. Y.; Yang, W.; Ni-Meister, W.; Schaaf, C.; Aleinov, I. D.; Jonas, J.; Zhao, F. A.; Yao, T.; Wang, Z.; Sun, Q.

2015-12-01

Processes determining biosphere-atmosphere coupling are strongly influenced by vegetation structure. Thus, ecosystem carbon sequestration and evapotranspiration affecting global carbon and water balances will depend upon the spatial extent of vegetation, its vertical structure, and its physiological variability. To represent this globally, Dynamic Global Vegetation Models (DGVMs) coupled to General Circulation Models (GCMs) make use of satellite and/or model-based vegetation classifications often composed by homogeneous communities. This work aims at developing a new Global Vegetation Structure Dataset (GVSD) by incorporating varying vegetation heights for mixed plant communities to be used as input to the Ent Terrestrial Biosphere Model (TBM), the DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM. Information sources include the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and plant functional types (PFTs) (Friedl et al., 2010), vegetation height from the Geoscience Laser Altimeter System (GLAS) on board ICESat (Ice, Cloud, and land Elevation Satellite) (Simard et al., 2011; Tang et al., 2014) along with the Global Data Sets of Vegetation Leaf Area Index (LAI)3g (Zhu et al. 2013). Further PFT partitioning is performed according to a climate classification utilizing the Climate Research Unit (CRU) and the NOAA Global Precipitation Climatology Centre (GPCC) data. Final products are a GVSD consisting of mixed plant communities (e.g. mixed forests, savannas, mixed PFTs) following the Ecosystem Demography model (Moorcroft et al., 2001) approach represented by multi-cohort community patches at the sub-grid level of the GCM, which are ensembles of identical individuals whose differences are represented by PFTs, canopy height, density and vegetation structure sensitivity to allometric parameters. To assess the sensitivity of the GISS GCM to vegetation structure, we produce a range of estimates of Ent TBM biomass and plant

Hidden vegetables: an effective strategy to reduce energy intake and increase vegetable intake in adults123

PubMed Central

Blatt, Alexandria D; Roe, Liane S

2011-01-01

Background: The overconsumption of energy-dense foods leads to excessive energy intakes. The substitution of low-energy-dense vegetables for foods higher in energy density can help decrease energy intakes but may be difficult to implement if individuals dislike the taste of vegetables. Objective: We investigated whether incorporating puréed vegetables to decrease the energy density of entrées at multiple meals reduced daily energy intakes and increased daily vegetable intakes. Design: In this crossover study, 20 men and 21 women ate ad libitum breakfast, lunch, and dinner in the laboratory once a week for 3 wk. Across conditions, entrées at meals varied in energy density from standard versions (100% condition) to reduced versions (85% and 75% conditions) by the covert incorporation of 3 or 4.5 times the amount of puréed vegetables. Entrées were accompanied by unmanipulated side dishes. Participants rated their hunger and fullness before and after meals. Results: Subjects consumed a consistent weight of foods across conditions of energy density; thus, the daily energy intake significantly decreased by 202 ± 60 kcal in the 85% condition (P < 0.001) and by 357 ± 47 kcal in the 75% condition (P < 0.0001). Daily vegetable consumption significantly increased from 270 ± 17 g of vegetables in the 100% condition to 487 ± 25 g of vegetables in the 75% condition (P < 0.0001). Despite the decreased energy intake, ratings of hunger and fullness did not significantly differ across conditions. Entrées were rated as similar in palatability across conditions. Conclusions: Large amounts of puréed vegetables can be incorporated into various foods to decrease the energy density. This strategy can lead to substantial reductions in energy intakes and increases in vegetable intakes. This trial was registered at clinicaltrials.gov as NCT01165086. PMID:21289225

Transverse and longitudinal variation in woody riparian vegetation along a montane river

USGS Publications Warehouse

Friedman, J.M.; Auble, G.T.; Andrews, E.D.; Kittel, G.; Madole, R.F.; Griffin, E.R.; Allred, Tyler M.

2006-01-01

This study explores how the relationship between flow and riparian vegetation varies along a montane river. We mapped occurrence of woody riparian plant communities along 58 km of the San Miguel River in southwestern Colorado. We determined the recurrence interval of inundation for each plant community by combining step-backwater hydraulic modeling at 4 representative reaches with Log-Pearson analysis of 4 stream gaging stations. Finally, we mapped bottomland surficial geology and used a Geographic Information System to overlay the coverages of geology and vegetation. Plant communities were distinctly arrayed along the hydrologic gradient. The Salix exigua Nuttall (sand-bar willow) community occurred mostly on surfaces with a recurrence interval of inundation shorter than 2.2 years; the Betula occidentalis Hooker (river birch) community peaked on sites with recurrence intervals of inundation between 2.2 and 4.6 years. The hydrologic position occupied by communities dominated by Populus angustifolia James (narrowleaf cottonwood) was strongly related to age of trees and species composition of understory shrubs. The fraction of riparian vegetation on surfaces historically inundated by the river decreased in the upstream direction from almost 100% near Uravan to <50% along the South Fork of the San Miguel River. In upstream reaches much of the physical disturbance necessary to maintain riparian vegetation is provided by valley-side processes including debris flows, floods from minor tributaries, landslides, and beaver activity. Where valley-side processes are important, prediction of riparian vegetation change based on alterations of river flow will be incomplete.

Using endmembers in AVIRIS images to estimate changes in vegetative biomass

NASA Technical Reports Server (NTRS)

Smith, Milton O.; Adams, John B.; Ustin, Susan L.; Roberts, Dar A.

1992-01-01

Field techniques for estimating vegetative biomass are labor intensive, and rarely are used to monitor changes in biomass over time. Remote-sensing offers an attractive alternative to field measurements; however, because there is no simple correspondence between encoded radiance in multispectral images and biomass, it is not possible to measure vegetative biomass directly from AVIRIS images. Ways to estimate vegetative biomass by identifying community types and then applying biomass scalars derived from field measurements are investigated. Field measurements of community-scale vegetative biomass can be made, at least for local areas, but it is not always possible to identify vegetation communities unambiguously using remote measurements and conventional image-processing techniques. Furthermore, even when communities are well characterized in a single image, it typically is difficult to assess the extent and nature of changes in a time series of images, owing to uncertainties introduced by variations in illumination geometry, atmospheric attenuation, and instrumental responses. Our objective is to develop an improved method based on spectral mixture analysis to characterize and identify vegetative communities, that can be applied to multi-temporal AVIRIS and other types of images. In previous studies, multi-temporal data sets (AVIRIS and TM) of Owens Valley, CA were analyzed and vegetation communities were defined in terms of fractions of reference (laboratory and field) endmember spectra. An advantage of converting an image to fractions of reference endmembers is that, although fractions in a given pixel may vary from image to image in a time series, the endmembers themselves typically are constant, thus providing a consistent frame of reference.

A coupled vegetation/sediment transport model for dryland environments

NASA Astrophysics Data System (ADS)

Mayaud, Jerome R.; Bailey, Richard M.; Wiggs, Giles F. S.

2017-04-01

Dryland regions are characterized by patchy vegetation, erodible surfaces, and erosive aeolian processes. Understanding how these constituent factors interact and shape landscape evolution is critical for managing potential environmental and anthropogenic impacts in drylands. However, modeling wind erosion on partially vegetated surfaces is a complex problem that has remained challenging for researchers. We present the new, coupled cellular automaton Vegetation and Sediment TrAnsport (ViSTA) model, which is designed to address fundamental questions about the development of arid and semiarid landscapes in a spatially explicit way. The technical aspects of the ViSTA model are described, including a new method for directly imposing oblique wind and transport directions onto a cell-based domain. Verification tests for the model are reported, including stable state solutions, the impact of drought and fire stress, wake flow dynamics, temporal scaling issues, and the impact of feedbacks between sediment movement and vegetation growth on landscape morphology. The model is then used to simulate an equilibrium nebkha dune field, and the resultant bed forms are shown to have very similar size and spacing characteristics to nebkhas observed in the Skeleton Coast, Namibia. The ViSTA model is a versatile geomorphological tool that could be used to predict threshold-related transitions in a range of dryland ecogeomorphic systems.

Effects of climate change on forest vegetation in the Northern Rockies Region [Chapter 6

USGS Publications Warehouse

Keane, Robert E.; Mahalovich, Mary Frances; Bollenbacher, Barry L.; Manning, Mary E.; Loehman, Rachel A.; Jain, Terrie B.; Holsinger, Lisa M.; Larson, Andrew J.; Webster, Meredith M.

2018-01-01

The projected rapid changes in climate will affect the unique vegetation assemblages of the Northern Rockies region in myriad ways, both directly through shifts in vegetation growth, mortality, and regeneration, and indirectly through changes in disturbance regimes and interactions with changes in other ecosystem processes, such as hydrology, snow dynamics, and exotic invasions (Bonan 2008; Hansen and Phillips 2015; Hansen et al. 2001; Notaro et al. 2007). These impacts, taken collectively, could change the way vegetation is managed by public land agencies in this area. Some species may be in danger of rapid decreases in abundance, while others may undergo range expansion (Landhäusser et al. 2010). New vegetation communities may form, while historical vegetation complexes may simply shift to other areas of the landscape or become rare. Juxtaposed with climate change concerns are the consequences of other land management policies and past activities, such as fire exclusion, fuels treatments, and grazing. A thorough assessment of the responses of vegetation to projected climate change is needed, along with an evaluation of the vulnerability of important species, communities, and vegetation-related resources that may be influenced by the effects, both direct and indirect, of climate change. This assessment must also account for past management actions and current vegetation conditions and their interactions with future climates.

Development of a biosphere hydrological model considering vegetation dynamics and its evaluation at basin scale under climate change

NASA Astrophysics Data System (ADS)

Li, Qiaoling; Ishidaira, Hiroshi

2012-01-01

SummaryThe biosphere and hydrosphere are intrinsically coupled. The scientific question is if there is a substantial change in one component such as vegetation cover, how will the other components such as transpiration and runoff generation respond, especially under climate change conditions? Stand-alone hydrological models have a detailed description of hydrological processes but do not sufficiently parameterize vegetation as a dynamic component. Dynamic global vegetation models (DGVMs) are able to simulate transient structural changes in major vegetation types but do not simulate runoff generation reliably. Therefore, both hydrological models and DGVMs have their limitations as well as advantages for addressing this question. In this study a biosphere hydrological model (LPJH) is developed by coupling a prominent DGVM (Lund-Postdam-Jena model referred to as LPJ) with a stand-alone hydrological model (HYMOD), with the objective of analyzing the role of vegetation in the hydrological processes at basin scale and evaluating the impact of vegetation change on the hydrological processes under climate change. The application and validation of the LPJH model to four basins representing a variety of climate and vegetation conditions shows that the performance of LPJH is much better than that of the original LPJ and is similar to that of stand-alone hydrological models for monthly and daily runoff simulation at the basin scale. It is argued that the LPJH model gives more reasonable hydrological simulation since it considers both the spatial variability of soil moisture and vegetation dynamics, which make the runoff generation mechanism more reliable. As an example, it is shown that changing atmospheric CO 2 content alone would result in runoff increases in humid basins and decreases in arid basins. Theses changes are mainly attributable to changes in transpiration driven by vegetation dynamics, which are not simulated in stand-alone hydrological models. Therefore LPJH

The long-term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA

USGS Publications Warehouse

Kui, Li; Stella, John C.; Shafroth, Patrick B.; House, P. Kyle; Wilcox, Andrew C.

2017-01-01

On alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56-year series of aerial photos on the dammed Bill Williams River (Arizona, USA) to investigate how (a) different woody riparian vegetation types influence river channel planform and (b) how different fluvial landforms drive the composition of riparian plant communities over time. We mapped vegetation types and geomorphic surfaces and quantified how relations between fluvial and biotic processes covaried over time using linear mixed models. In the decades after the dam was built, woody plant cover within the river's bottomland nearly doubled, narrowing the active channel by 60% and transforming its planform from wide and braided to a single thread and more sinuous channel. Compared with native cottonwood–willow vegetation, nonnative tamarisk locally induced a twofold greater reduction in channel braiding. Vegetation expanded at different rates depending on the type of landform, with tamarisk cover on former high-flow channels increasing 17% faster than cottonwood–willow. Former low-flow channels with frequent inundation supported a greater increase in cottonwood–willow relative to tamarisk. These findings give insight into how feedbacks between abiotic and biotic processes in river channels accelerate and fortify changes triggered by dam construction, creating river systems increasingly distinct from predam ecological communities and landforms, and progressively more resistant to restoration of predam forms and processes.

Indicators: Lakeshore Habitat/Riparian Vegetative Cover

EPA Pesticide Factsheets

Riparian and lakeshore vegetative cover consist of the vegetation corridor alongside streams, rivers, and lakes. Vegetative cover refers to overhanging or submerged tree limbs, shrubs, and other plants growing along the shore of the waterbody.