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

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Insert 25 plastic collars (=tubes of about 10 cm length) per ha into the soil at the centres of each subplot (findthe central point by having two people standing at adjacent corners using their compasses to direct a thirdperson to the middle point). Install by simply hammering each gently into the soil, leaving over half (5-7 cm)above ground (this ensures a close seal whilst minimising soil and root disturbance) and labelling the collar“SR” for “soil respiration”. After installation, leave all collars to ‘settle’ for at least a few days before firstmeasurement.Record CO 2 efflux (respiration) with the IRGA and SRC system from each collar every month (Appx.II). At each measurement, record the height of the portion extending out of the soil for each collar (to calculateV a for the volume correction, Appx. II, allowing for settling of collars into the soil). After every measurement,record soil moisture and temperature (i) inside every collar and the depth of accumulated litter and (ii) outsideevery collar at least 20 cm away in a random direction (best is to measure both at three different points andaverage). For analysis calculations, see Appx. II.Jeffry Amin with a soil collar in the Fragment E plot in Sabah, Malaysia.Equipment: 25 PVC collars (10 cm long and of a diameter to fit the SRC-1, see Appx. II), two compasses (if ina team of 3), a rubber-topped mallet and a permanent marker pen.Time required: estimate half a day to do a 1 ha plot in a team of two.n.b. As noted by Chambers et al. (2004) at their valley forest sites, surface roots in forests tend to aggregate atcertain points, preventing installation of soil collars. This will slightly bias total soil CO 2 efflux readingstowards lower values, but this effect may be assumed to be negligible.n.b. (2) Heinemeyer et al. (2011) highlighted the importance of the fact that surface fine roots are (necessarily)cut during collar insertion to 5 cm depth in the method described here. This not only artificially reduces soilCO 2 efflux but also removes the nocturnal peak in root respiration during moist periods measured when collarsare not inserted. We currently do not correct for these effects of soil collars in our measurements.50
3.2 Stem CO 2 effluxFirst, choose the trees to have stem collars (from the census data) and generate the list of tree numbers: Selecttwo trees >25 cm diameter per subplot randomly (e.g. using a spreadsheet on a computer), i.e. 50 stems per ha(make sure that this selection includes all trees with dendrometer bands). If there are less than two trees >25cm in any subplot, select randomly from the 20-25 cm trees or, if still not enough trees, leave that subplot with0 or 1 stem collar only.Next, in a team of 2 (one holding each collar on the tree, the other applying the sealant), find eachselected tree. Position the collar at 1.5 m height (i.e. 10 cm below the tag; if the POM is at 1.5 m, install thecollar above the tag at 1.7 m; in areas where elephants occur, put at >2.0 m height (record the height)following current practice in Gabon) but on the opposite side of the tree stem from the tag (if possible: if thestem is irregular, find a flat section of stem at 1.5 m height somewhere around the stem, avoiding buttresses).Before installation, clear loose bark, termite nests, ant trails (etc.) from the stem. Apply sealant and fix thecollar to the stem (above the bark), ensuring that none is applied to the inside of the collar (i.e. all bark insidethe collar is sealant-free: very important for the volume correction in Appx. II) and that the seal between thecollar and stem is complete without holes.51
Page 1:
Measuring Tropical ForestCarbon All
Page 5 and 6: ContentsTHE RAINFOR-GEM INTENSIVE C
Page 7 and 8: The RAINFOR-GEM Intensive Carbon Mo
Page 9 and 10: What are the RAINFOR-GEM protocols?
Page 11 and 12: Where can I get data from existing
Page 13 and 14: 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: 3. CO 2 EFFLUX3.1 Total soil CO 2 e
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 and 66: the S3 hole. Finally, discard the l
Page 67 and 68: 3.4 Coarse woody debris (CWD) CO 2
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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