Jornada Basin LTER Research

Data by Research Category
All Projects Datasets
Animal Projects Datasets
Climate Projects Datasets
Decomposition Projects Datasets
Hydrology Projects Datasets
Plant Projects Datasets
Soil Projects Datasets

Dataset: Conmod Pilot Study: Bedload data


   File description including attribute definitions: data_Jornada_308003_conmod_pilot_bedload
   Original Investigator: Jeff Herrick
   Duration: 2008 - 2010
   Dataset ID: 210308003
   DOI: 10.6073/pasta/47d62ed56602989b5ad0d24d8a9cd1ff
   Abstract:

    Material moved from the overland flow of water resulting from precipitation is collected in
    belowground containers to get an estimate of that material entering and exiting the plots.
    Water and material collected in a container solely from a rain or wind event is not collected.
    Bedload oven-dry weight is obtained and the percent Loss on Ignition is calculated.


   Additional information:

   There are 3 site locations:  Aeolian, Dona Ana, Gravelly Ridges.  The UTM coordinates
   below are approximate, and based on the UAV photo coverage we have for each site.
   Precise GPS coordinates are available.

   Dona Ana.  These are located north of Herrick's SD97C (Surface Disturbance) exclosure,
   which is north of the Dona Ana exclosure, which is in the SW corner of JER Pasture 6..

   DA1     334992.42476300000      3596630.43159000000
   DA2     334992.42675400000      3596112.28705000000
   DA3     335490.35961900000      3596112.30170000000
   DA4     335490.36881400000      3596630.40896000000

   Aeolian. These are located just east of the gas pipeline, near the scrape site.
   AE1     334253.41442800000      3606226.21293000000
   AE2     333263.17702400000      3606226.21887000000
   AE3     333263.16474900000      3605411.37177000000
   AE4     334253.40961100000      3605411.35650000000

   Gravelly Ridges.  These are located south of the SE corner of the Gravelly Ridges
   exclosure, north of the road to NASA.  All are outside of the exclosure.

   GR1     350381.01412200000      3604795.02860000000
   GR2     349883.09428900000      3604795.02926000000
   GR3     349883.11877100000      3604276.88904000000
   GR4     350381.05237400000      3604276.87003000000

   Methods:

field data sheets, lab data sheets

    FIELD COLLECTION:
    Connectivity Bedload Samples are collected or cleaned out once a month.  Before arriving to field, check weather records to get an estimate of rainfall over last month.  This will help determine whether there was a flow event.  However, this is not the sole basis of whether or not to collect the bottles. Upon arriving to field, check bottles to make sure there was/wasn't a flow event.  If there is bedload, a decent amount of water, or dried water lines in bottle, then there was probably a flow event.  If there is only litter and/or very little, loose, wind blown soil in bottle, then there probably was not a flow event.  Only material from bedload (material moved from overland flow of water) is considered; water and material in a bottle solely from a rain or wind event is not collected.

    Materials Needed:
    *       enough clean bottles to exchange each one (98 clean bottles = 32 at both Dona Ana & Gravelly Ridges; 34 at Aeolian)
    *       small boxes for carrying bottles
    *       bedload databook (in top drawer of file cabinet)
    *       pencil
    *       The bedload bucket (contains trowel, cups, and vice grips)

    Collecting (if there was a flow event):
    *       Do not collect sample bottle if a) there is no soil sample in bottle from bedload flow or b) if bottle is completely full of sediment. See section "Collecting (if there was not a flow event."
    1.      Record any problems/disturbances that are on or around plate. Also, record if there are substantial amounts of sediment on plate, if there are lizards/other animals in bottle, erosion around the plate, if the intake hole is clogged, or if the bottle is completely full of sediment. Note: Do not collect bottle if it is completely full of sediment because it won't provide useable data. The contents can be discarded in the field and the bottle replaced with a clean one.
    2.      Lift plate carefully and unscrew bottle minimizing bottle agitation.
    3.      Carefully decant off excess water from bottle without losing sediment. Don't worry about floating litter loss during decanting. It is the bedload sediment that is of interest.
    4.      Record bottle number (on bottle) that is being collected in databook to corresponding site and plate number (on lid riveted to bottom of plate).
    5.      Replace the collected bottle with a clean new one and place that lid on the bottle being collected. (Do not record the number of the new clean bottle.)

    Collecting (if there was not a flow event):
    1.      Record any problems/disturbances that are on or around plate. Also, record if there are substantial amounts of sediment on plate, if there are lizards/other animals in bottle, erosion around the plate, if the intake hole is clogged, or if the bottle is completely full of sediment (which it shouldn't be if there was no flow event).
    2.      Lift plate carefully and unscrew bottle.
    3.      Empty out litter/wind blown soil from bottle.  If really dirty, take clean bottles to field and exchange them.
    4.      Replace bottle.
    5.      Do not record the bottle numbers in the databook if they are not being collected.  However, comment on datasheets that the bottles were cleaned out but not collected at that time and date.

    LAB PROCESSING:

    After Arriving from Field:
    1.      After bedload bottles are brought in from field, rinse off outside of bottles thoroughly. (We don't want sample+bottle weight to include any material stuck to the outside of the bottle.)
    2.      Remove lids and place in large plant drying-oven in Rm 161 for 72 hours or until completely dry. It may take additional drying days depending on how much water is left in the bottle after decanting. Large amounts of sediment will take longer to dry than a small amount.
    3.      Remove from oven and weigh bottles (still containing soil) without the lids and record on datasheet to 2 decimal places.
    4.      Replace lids and place on shelf until further processing is done.

     Processing Steps:
    1.      Samples under 5 grams will not be processed and can be thrown out. All samples over 5 grams NEED TO BE PROCESSED.
    2.      Blow out soil/dust from crucibles before using. DO NOT USE WATER TO CLEAN.
    a.      Any water retained in crucible could cause it to explode in muffle furnace.
    3.      Record crucible i.d. number located on bottom (underside) of crucible.
    a.      Don't use any number that may be located on the side of the crucible unless there is no number on the underside of the crucible.
    4.      Record weight of empty crucible to 2 decimal places (xx.xx g)
    5.      Scrape out bottles thoroughly, but not as too scratch the insides of the bottles. A long handled spoon spatula seems to work nicely.
    6.      Transfer samples from plastic bottles to crucibles.
    a.      Be careful not to lose sample in the process. This is most readily done by emptying sample from bottle onto a large, clean sheet of paper from which the sample can be slid into the crucible.
    b.      Large samples that will require multiple crucibles can be reduced in size to fit one crucible using a soil splitter.  It is okay to use multiple crucibles if does not add significantly to the processing time. Since reducing the sample with the soil splitter homogenizes it and thus provides the same percent organic component data as doing multiple crucibles, use the method (multiple crucibles or soil splitter) that is the most efficient.
    c.      To split samples:
    i.      Use the ½" soil splitter located in Rm 161, Cabinet #10, to reduce the volume of the sample.
    ii.     Since the bedload plate in the field is ½" diameter, you won't have stones larger than that. However, if necessary to breakup dirt chunks larger than ½", sieve sample using ½" sieve (found on upper center shelf in Rm 161).
    iii.    Pour entire sieved sample into the splitter hopper and evenly spread out the sample by hand.
    iv.     Lift the trap door lever and allow the sample to fall through the vanes.  Then tap the lever on the hopper and/or lift the entire splitter off the table and lightly vibrate or tap it against the table.  This will encourage any soil particles sticking to the splitter to fall into the receptacle bins.
    v.      All of the contents of either bin can be used for the crucible sample.  Alternately, if bin sample is too large for 1 crucible, select which bin is saved for re-splitting and which is discarded, and then repeat as many times necessary to reach the desired sample size.
    vi.     Add sample to pre-weighed crucible.
    7.      Oven-dry crucible+sample at 105 C for 24 hours in soils drying oven in Rm 141 alcoves. Sign-out oven use on calendar on oven door.
    8.      Record weight of oven-dry crucible+sample after allowing to cool in desiccator cabinet (so sample doesn't reabsorb moisture from the air).
    a.      Crucibles that won't fit in desiccator should be kept in a drying oven (50-60 C is fine) until there is room.
    b.      May need to reheat in soil drying oven at 105 C for 2 hours before weighing if won't be weighed immediately out of drying oven.
    9.      Muffle crucibles at 400 C for 8 hours.
    a.      Do not stack the crucibles in the muffle furnace. It is alright if they touch each other.
    b.      Place the crucibles on the short ceramic platform that sits on the bottom of the muffle furnace. Do not place crucibles directly on the floor of the muffle furnace.
    c.      Exhaust vent on top of muffle furnace should be closed during muffling.
    10.     Allow crucibles to cool within muffle furnace with door closed. After about 2 hours you can pull up vent on top of furnace to facilitate cooling. Leave it closed if left to cool overnight.
    Do Not open door of muffle furnace until crucibles are no longer hot. Best if left to cool overnight.  Opening door before the (expensive) crucibles cool sufficiently will cause them to break from sudden temperature change.
    11.     Transport crucibles on metal rack.
    12.     Weigh crucibles+muffled sample to 2 decimal places (xx.xx g).
    13.     Discard soils in bucket for disposal in field. Do not put quantities of soil in trash.
 

   Maintenance:

monthly