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Leaf Leaching Experiment. Monday PM. David A. Reckhow University of Massachusetts. Introduction. - PowerPoint PPT Presentation

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Leaf Leaching Experiment

Leaf Leaching ExperimentMonday PM

David A. ReckhowUniversity of MassachusettsIntroductionWater treatment engineers and public health officials need to pay careful attention to the presence of dissolved organic matter in water supplies selected for human consumption (i.e., raw drinking waters). For many reasons related to human health and cost, it is necessary to remove a substantial amount of these organic compounds before the water is ready for human use. The cost of doing this is highly variable and dependent on the particulars of the ecosystem from which the raw water originates. In the Northeast US, a large fraction of aquatic organic matter found in lakes and rivers comes from the forest floor. Were all familiar with organic-rich soils with upper soil horizons containing roots, branches, logs and leaves in various stages of decay.

Intro (cont.)Thinking about the fate of plant biomass, many questions come to mind. How much of this plant biomass degrades to CO2 and H2O in place (i.e., the process of mineralization), how much becomes incorporated in the soil below and how much becomes dissolved in pockets of water and is carried away to groundwater and surface water bodies (i.e., solubilization)? How quickly does this happen and do leaves age and degrade at the same rate for all species under all conditions? What are the steps in degradation and solubilization? Does decomposition/degradation and solubilization occur at a constant rate, or an increasing or decreasing rate with time? Is there a lag phase?MaterialsContainers for leaching & imagingPlastic Culture Flasks (275 mL), Corning #430720; $3.70 each from Fisher ScientificPlastic AquariumKritter Keeper (Large), Lees Aquarium & Pet Products$14 from local pet storeScale (reading in grams)I used a postal scale, but top loading balance is betterPlant BiomassYour backyardTap WaterCamera, computer & ADI softwareLeaching DOM from LeavesAbout 7 g of leaves in 10 L of waterGood for UV abs, but 20g is better for visual assessment

B: Oak/Maple Aged 7 moI: GoldenrodFreshBlank: Tap waterNo leaves5zcx

Line Tool: Aquariaxcz

BIBlankAquaria vs BottlesDifferent Pathlengths9 cm for bottles32 cm for aquaria (better for low level leaching)Aquaria still have plant biomassBottles allow separation, or decantation of leaching mixtureAquaria are good for producing large volumes of leachate (~10L) for later testingBottles (Culture flasks) hold ~75 mLPhotographic Image: Bottles

Blank in middleExperimental on either side7g/tankprobably too lowWhite backgroundID labels belowLine Tool

lineLine Tool: Color along line All three

BIBlankWith image

Rectangle Toolhistogram

Rectangle Tool: I bottle50blank

Rectangle Tool: Blank bottle64B sample

Rectangle Tool: B bottle42Data AnalysisFind location of blue peak for each rectangle on the color intensity scaleCalculate difference between this value and the value for the blank (tap water); this is the color lostPlot color lost vs leaching timeThis will show the accumulation of released colored organic matter from the leavesLeaching RatesLeaching rates from the scientific literatureAmount released each weekDiminishes with time for some, accelerates for others

From: Magill and Aber, 2000Soil Biology & Biochemistry, vol. 32, pp.603-613Composition of an average leaf250 g/m2/yr EABPDave Reckhow18

Highly-coloredSome color

Source:Terrestrial EcosystemsAber & Melillo2nd editionHarcourt Academic PressVariations based on Species

Phenolic AcidsReadily released, highly coloredLigninVery slowly released, some colorColored CompoundsSimple sugarsReadily released, highly biodegradableStarchEasily released and also biodegradableCellulose & HemicelluloseSlow to solubilize, not easily degraded

Colorless Compounds

Constituents degrade at different ratesSolubles go firstFree carbohydrates are nextBound or Lignified carbohydrates and Lignin are lastSolubilization vs Total LossDOC-C loss versus total C loss in mg C. Y-axis values are mean leached DOC concentration for the 15 week treatment X-axis values are total C loss from litter.

33% solubilization12.5%SolubilizationMapleOakPineRe-drawn from Magill and Aber, 2000What to Do for the Leaching Tests?MondayStep 1: decide on plant material to useStep 2: select and weigh out sufficient biomassId recommend something between 20 and 100 gramsStep 3: add biomass to a plastic aquariumStep 4: fill with tap water to 4 cm below topThis will give you a total volume of 10 LitersTuesday, Wednesday, ThursdayCollect one photographic image of aquarium next to blankFridayCollect final aquarium photo and begin treatment testsStep 1: Select LeavesBiomass smorgasbordLabelShort DescriptionNotesA28 Month Aged Oak/Maple litterfallPartially degraded from 2010 growing season, collected in March 2012B19 Month Aged Oak/Maple litterfallPartially degraded from 2011 growing season, collected in June 19, 2012C19 Month Aged Oak on TreeCollected from Fitzgerald Lake Conservation area on June 23, 2012 branches that probably fell during the 10/30/2011 stormD19 Month Aged White PineCollected from Fitzgerald Lake Conservation area on June 23, 2012 - branches that probably fell during the 10/30/2011 stormE12 Month Aged OakCollected from freshly cut branches on June 23, 2012, aged in bagF12 Month Aged Cherry Collected from freshly cut branches on June 23, 2012, aged in bagGFresh OakCollected from freshly cut branches on June 23, 2013HFresh Cherry Collected from freshly cut branches on June 23, 2013Extra Topic: Beers LawConcentration of a pure solution of an absorbing compound is directly proportional to the logarithm of the light intensity for experimental (I) divided by the light intensity for the blank (Io)This is the Absorbance

Fixed valueFixed valueCreate Useful File Name to SaveImageTrimmed DSCN4373.JPGUnaltered RGB ImageScaling Factor-1X1 = 156Y1 = 90X2 = 242Y2 = 335Cumulative Frequencies of Color Intensities for Selected AreaCumulative Frequencies of Color Intensities for Full ImageColor Intensity (0-255)Frequency of Red IntensityFrequency of Green IntensityFrequency of Blue IntensityFrequency of Red IntensityFrequency of Green IntensityFrequency of Blue Intensity0000.00032550001000.0006510002000.00292970003000.00878910004000.01367190005000.0387370006000.07194010007000.13216150008000.21354170009000.32910160001000.00032550.3629557000110.00065100.4147135000120.00162760.00358070.4169922000130.00292970.0074870.4446615000140.00520830.01204430.4508464000150.00911460.0231120.4186198000160.01302080.03450520.4410807000170.02050780.05891930.3857422000180.01790360.08105470.3072917000190.02115890.11458330.2763672000200.02766930.17643230.2096354000210.03515630.22428390.1806641000220.04524740.29231770.1614583000230.05729170.34635420.1474609000240.06705730.36783850.133138000250.10058590.36783850.1350911000260.13411460.37109380.1295573000270.18945310.38704430.132487000280.24348960.36230470.1549479000290.28678390.3430990.1695964000300.35481770.33333330.1790365000310.35970050.31542970.1809896000320.38802080.30208330.1901042000330.3587240.25227860.1998698000340.34733070.22916670.1842448000350.35839840.16634110.1816406000360.32584640.14160160.1660156000370.2975260.10807290.1787109000380.30013020.11490890.1767578000390.26074220.09765630.1702474000400.24772140.09179690.1767578000.0046725410.22005210.1100260.1933594000420.19108070.1012370.2076823000430.17578130.1012370.2057292000440.1481120.10058590.2005208000450.15104170.09277340.2001953000460.13085940.09765630.1861979000470.13216150.1087240.1692708000480.12337240.12337240.1549479000490.11946610.14322920.1777344000500.11132810.18326820.1861979000.0046725510.10709640.20768230.2233073000.0093449520.10807290.23697920.2516276000530.11458330.2425130.2695313000.0046725540.12597660.26106770.2867839000.0046725550.15657550.25585940.3245443000.0140174560.16471350.21386720.3466797000.0046725570.20703130.20279950.3391927000.0186898580.2112630.20638020.333007800.00467250.0046725590.21256510.19401040.3411458000.0233623600.22200520.19791670.312825500.00467250.0046725610.26171880.19531250.327474000.0420521620.30240890.21972660.3398438000.0373797630.30566410.24707030.36067710.009344900.0280348640.30566410.29524740.4394531000.0373797650.3199870.33398440.5009766000.0373797660.31640630.34147140.5397135000.0560695670.31022140.35416670.6048177000.0654144680.32486980.38704430.5843099000.060742690.32421880.42675780.5751953000.0747594700.37011720.43098960.6035156000.0560695710.40917970.4300130.6207682000.0560695720.43196610.43326820.6458333000.060742730.45768230.43945310.6416016000.0420521740.43131510.48860680.632487000.0700869750.45410160.54069010.6197917000.0747594760.47851560.57259110.665690100.00467250.0934492770.50618490.58268230.66113280.00934490.00467250.1074666780.50651040.62923180.712239600.00934490.1261564790.58528650.57779950.772135400.00467250.1074666800.59537760.55826820.81087240.00467250.00934490.1448463810.64420570.51822920.85514320.00467250.00934490.1401738820.62174480.48404950.84830730.00934490.00934490.121484830.60319010.43326820.79296880.00467250.02803480.1401738840.55598960.42057290.70670570.00467250.02336230.1261564850.5319010.39192710.61783850.004672500.2102607860.43619790.37630210.5231120.01868980.00467250.2616578870.40006510.40104170.40462240.01401740.01401740.2663302880.39225260.39713540.33593750.02336230.01401740.4625736890.40201820.41536460.33365890.00934490.03737970.5186431900.3981120.40527340.28971350.00934490.01401740.6541445910.39485680.40787760.29394530.00934490.03270720.8410429920.43489580.45084640.29003910.02336230.01401741.098028930.42089840.49869790.33496090.00934490.03270721.467153940.44368490.52408850.35839840.00934490.04672461.934399950.43750.57779950.3981120.00934490.02803482.177367960.48144530.5787760.42578130.02336230.03737972.420335970.47460940.51660160.43619790.01868980.0607422.5