RAINFOR GEM Intensive Plots Manual (pdf) - University of Oxford

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Partitioning Experiment protocol option 1: Data analysisThe partitioning experiment should allow estimation of the relative contributions of (1) surface organic litter, (2) roots, (3)mycorrhizae and (4) soil organic matter to total soil CO 2 efflux. Contributions are estimated from differences betweencollars subjected to different treatments, in excess of pre-existing spatial variation (NV).Fine litter CO 2 efflux (decomposition): First calculate NV (proportion of ambient) for collars from the two litter treatments(zero and double litter level) from the CO 2 efflux measurements made on surface collars temporarily installed at alllocations before collar installation:NV for zero litter = (column C – column S) / column C (e.g. for S1 = (C1 – S1) / C1)NV for double litter = (column D – column C) / column CAfter collar installation calculate litter CO 2 efflux (proportion of ambient) in excess of NV from the measurements aftercollar installation with:Zero litter = NV value for zero litter – ((column C – column S) / column C)Double litter = NV value for double litter – ((column D – column C) / column C)Root CO 2 efflux: Calculate NV (proportion of ambient) for the relevant collars (rows 1 & 2) from the CO 2 effluxmeasurements made on surface cores installed at all locations before collar installation:NV = (row 1 – row 2) / row 1 (e.g. for C2 = (C1 – C2) / C1)Then, to remove any additional influence of the different levels of disturbance experienced by the soil in row 2 comparedto the surface collars of row 1, calculate mean CO 2 efflux from disturbed (DC d ) and undisturbed (DC ud ) deep cores(above). Finally to calculate root CO 2 efflux (R root , proportion of total ambient soil CO 2 efflux) in excess of NV andcontrolling for collar installation disturbance from the measurements after collar installation use:R root = NV – ( ((row 1 – row 2) / row 1) * (DC ud /DC d ) )Mycorrhizal CO 2 efflux: Calculate NV (proportion of ambient) for the relevant collars (rows 2 & 3) from the CO 2 effluxmeasurements made on surface cores installed at all locations before collar installation:NV = (row 2 – row 3) / row 2 (e.g. for C3 = (C2 – C3) / C2)Now, to calculate mycorrhizal CO 2 efflux (R mycorr , proportion of total ambient soil CO 2 efflux) in excess of NV from themeasurements after collar installation use:R mycorr = NV – ((row 2 – row 3) / row 2)Soil organic matter CO 2 efflux: Calculate NV (proportion of ambient) for the relevant collars (rows 1 & 3) from the CO 2efflux measurements made on surface cores installed at all locations before collar installation:NV = row 3 / row 1Then, to remove any additional influence of the different levels of disturbance experienced by the soil in row 2 comparedto the surface collars of row 1, calculate mean CO 2 efflux from disturbed (DC d ) and undisturbed (DC ud ) deep cores(above). Finally to calculate soil organic matter CO 2 efflux (R SOM , proportion of total ambient soil CO 2 efflux) in excessof NV and controlling for collar installation disturbance from the measurements after collar installation use:R SOM = NV – (row 3 / row 1) * (DC ud /DC d )60
3.4 Coarse woody debris (CWD) CO 2 effluxEquipment: IRGA and SRC, PVC collars (5 cm long and of a diameter to fit the SRC-1, see Appx. II), plasticsheet, strong adhesive tape, callipers, weighing balance (0.01 g resolution), drying ovenTake these measurements every two months (usually at the same time as the survey in §4.2). Collect 5representative wood pieces (~5 cm long, i.e. small enough to fit into a PVC collar without sticking out) of eachdecomposition category from each plot (5 pieces per category * 5 categories = 25 pieces per ha), and place inappropriately marked sealed plastic bags (site, plot, date, piece number). Seal one side of a plastic collar with aplastic sheet secured with tape. Then place each individual piece of wood into the collar, place the SRC firmlyonto the collar and commence IRGA measurement (Appx. II). Now measure for each wood piece: (1) wetweight, (2) dry weight, after drying to constant mass at 80 o C, (3) diameter and (4) length. Ensure that theidentity of each individual piece is noted, so that these measurements can be matched to the correspondingefflux value from the same piece.Decomposition Level (following Harmon et al.1995 71 )1 (little decay: bark cover extensive and leavesand fine twigs present)2 (logs and snags relatively undecayed but withno leaves and few fine twigs and bark has startedto fall off)3 (logs and snags with no bark and only a fewbranch stubs remaining; although in this class thesapwood is decaying, the heartwood is relativelyundecayed, and branch stubs do not move whenpushed or pulled)4 (no branches or bark cover; outer portions ofthe wood are often casehardened and the innerwood is decomposing)5 (logs are elliptical in cross-section (indicativeof advanced decay) and often the wood isscattered across the soil surfac)LeavespresentFinetwigspresentIntactbarkFirmwoodSoftwoodyes yes yes yes no nono no yes yes no nono no no yes no nono no no no yes nono no no no no yesVerysoftwoodThe mean difference between wet and dry weight for each decomposition category will provide a woodmoisture correction necessary for the previous section. Estimate the surface area of each piece using (2 *3.1416 * ((diameter/2) 2 )) + (2 * 3.1416 * (diameter/2) * length). Dry weight and surface area can then be usedto calculate CO 2 efflux per unit dry mass and surface area using the approach described above (also see Appx.II). These values may be scaled up to a per ha estimate of CO 2 flux using estimates of ground coarse litter massand surface area (see §4.2).71 n.b. these categories differ slightly from those in Baker & Chao (2011).61
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Measuring Tropical ForestCarbon All
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ContentsTHE RAINFOR-GEM INTENSIVE C
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The RAINFOR-GEM Intensive Carbon Mo
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What are the RAINFOR-GEM protocols?
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Where can I get data from existing
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Two RAINFOR-GEM hectare plots in th
Page 15 and 16: 1.2 Setting out the plotSubplot cor
Page 17 and 18: An example surveying path (cf. Cond
Page 19 and 20: Required for jobs that can be sched
Page 21 and 22: Tree #487 in Fragment E plot where
Page 23 and 24: 1.4 Tagging small trees*** Note tha
Page 25 and 26: does, measure underneath the lean o
Page 27 and 28: Measuring a liana at three points i
Page 29 and 30: BOX 2: Five unusual trees.Example 1
Page 31 and 32: Example 3: Here is a large liana on
Page 33 and 34: 1.5 Tree heightTree height should b
Page 35 and 36: 1.6 Sketch map of the plotAt this p
Page 37 and 38: 2. BELOW GROUND MEASUREMENTSWe star
Page 39 and 40: Next, insert the cylindrical core i
Page 41 and 42: BOX 3: How to make an in-growth cor
Page 43 and 44: 2.2 RhizotronsRoot observation pits
Page 45 and 46: sure that it covers the hole but no
Page 47 and 48: An example rhizotron transparency f
Page 49 and 50: Analysis: First, calculate the sum
Page 51 and 52: A metallic rhizotron as in use at t
Page 53 and 54: 2.3 Coarse rootsNeither in-growth c
Page 55 and 56: 3. CO 2 EFFLUX3.1 Total soil CO 2 e
Page 57 and 58: 3.2 Stem CO 2 effluxFirst, choose t
Page 59 and 60: e related to stem growth) to check
Page 61 and 62: Equipment: IRGA and SRC-1, PVC coll
Page 63 and 64: Control No litter Double litterNo e
Page 65: the S3 hole. Finally, discard the l
Page 69 and 70: 4.2 Coarse woody debris (CWD) surve
Page 71 and 72: all of the large, marked wood piece
Page 73 and 74: Equipment: 25 litter traps per ha (
Page 75 and 76: this select the straight line drawi
Page 77 and 78: http://www.eci.ox.ac.uk/research/ec
Page 79 and 80: • The tripod is level so that the
Page 81 and 82: 8. WEATHER AND CLIMATELocal climate
Page 83 and 84: Luiz Aragão repairing an understor
Page 85 and 86: 10. DATA ENTRY AND SERVER UPLOADA c
Page 87 and 88: APPENDIX I: RAINFOR-GEM Fieldwork c
Page 89 and 90: APPENDIX II: How to use an EGM-4 In
Page 91 and 92: • Remember to change the switch i
Page 93 and 94: CO 2 efflux calculationsWhile the E
Page 95 and 96: The volume V airspace (stippled) be
Page 97 and 98: CO 2 flux measurements with EGM: A
Page 99 and 100: Downloading dataEGM memory can stor
Page 101 and 102: APPENDIX III: Possible schedule of
Page 103 and 104: Gerwing JJ, Schnitzer SA, Burnham R
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