Conmod Pilot Study: Annual plant canopy gap and basal gap intercept data

Data Access: 


Dataset status: 

Study number: 


Data set ID: 


Date range: 

2006-06-10 to 2009-07-11

Original investigator: 

Debra Peters


Canopy Gap and Basal Gap Intercept data are collected annually for this project beginning in 2008. No data were collected in 2011. There are 4 pairs of plots consisting of control and treatment. Each plot is 8x8 meters with an 8x8 meter buffer plot above and below it. Treatment plots have connectivity modules (conmods) installed to decrease gap size between perennials. Buffer plots do not have conmods. Four 24-meter transects run through the plot and 2 buffer plots. These transects are spaced 0.8, 2.8, 4.3, and 7.2 meters across the plots (denoted as 1, 3, 5, and 7 meters in the database), paralleling the long axis of the combined buffer plots and central plot.
Aeolian site:                Control plots 2,4,5,8  Treatment plots 1,3,6,7
Dona Ana site:            Control plots 2,4,5,7  Treatment plots 1,3,6,8
Gravelly Ridges site:  Control plots 1,3,5,7  Treatment plots 2,4,6,8


Methods of recording:

Database for Inventory, Monitoring, and Assessment (DIMA) data entry program used on field tablet


Methods follow "Herrick, JE, JW Van Zee, KM Havstad, LM Burkett, WG Whitford. 2005. Monitoring Manual
    for Grassland, Shrubland and Savanna Ecosystems. Volume I:  Quick Start". Specifics relative to this
    study are given below.
    LTER Connectivity Monitoring Methods and Notes - Update 2010
    ** Be sure not to step inside the coop rebar (visualize a square roof on top) when
      measuring transects.**
    ** Don't forget to calibrate.**
    Plot Setup
       o There are 3 sites:  Dona Ana, Aeolian, and Gravelly Ridges.  Each site has 4 control
         plots and 4 treatment plots.  In addition to each 8m x 8m plot, two buffer plots of the
         same size are located at each end of the plot- one upwind/upslope and one downwind/down
         slope. Central 8m x 8m treatment plot has connectivity modifiers (conmods) installed; buffer plots do not.
         Aeolian site:         Control plots 2,4,5,8  Treatment plots 1,3,6,7
         Dona Ana site:        Control plots 2,4,5,7  Treatment plots 1,3,6,8
         Gravelly Ridges site: Control plots 1,3,5,7  Treatment plots 2,4,6,8
       o Plot IDs:  Plot number = control/treatment plot; Buffer Up = buffer upwind/upslope;
         Buffer Down = buffer downwind/down slope
       o Aeolian & Dona Ana sites:  The 0 end of Line 1 should be in the NW corner.  Lines are
         read from west to east.
       o Gravelly Ridges site:  The 0 end of Line 1 should be in the NE corner.  Lines are read
         from north to south.
       o Four 8m transects are located at 0.8, 2.8, 4.3, and 7.2m (1, 3, 5, and 7m in database)
         in each control/treatment plot and in both buffer plots.  Metal rods have been placed in
         the far corners of each buffer plot and rebar have been placed at the 0m and 24m ends of
         each transect; metal tags indicating transect number (i.e.  Line 1, 0.8m) are attached
         to the 0m rebar.  Note that the 24m mark of each tape will not always fall exactly at
         the 24m rebar.
       o Once transects are strung, place flags at the 8m and 16m marks.  After reading all four
         lines of the first buffer plot, reel in each tape until the new 0m is at the old 8m mark
         (where flag is).  Read each line of the control/treatment plot and repeat for last
         buffer plot.
       o Spacing Interval:  25cm
       o Use the check box function (called coop) in the database when a coop is within a 12.5 cm
         radius from the sample point.  The point can also fall behind or on the other side of
         the line.
       o If you hit the coop with your LPI pin, you will select coop in the proper canopy order
         in that database and you will also select the check box.
       o Measure maximum and dropped heights at 1, 3, 5, & 7m.
       o Disk height method rules:
         1. Place rod ~30cm away from the tape at each point.  Record the maximum height to the
            nearest 1 cm.  Raise the disk 5cm and let fall.  Record the dropped height to the
            nearest 1 cm.
         2. Treat litter, live & dead plants the same.
         3. If no plant under disk & drop ht is >0cm, record "0".
         4. If plant is under disk and drop ht is >0cm, BUT plant is not holding up the disk and
            rock or soil is, record "0".
         5. When "0" is recorded as dropped ht, max ht may be 0 (if no plant under disk) or    a
            number (if needed, measure plant using only the rod).
         6. If plant occurs under litter & litter is taller, use litter ht.
         7. If no plant is under disk & disk is at 0cm, record "0".
         8. If plant is under disk & disk is at 0cm, record "0".
         9. If a maximum and/or dropped ht is resting on an obstruction (coop) or rod:  use just
            the height rod to make a maximum height reading of the highest plant that would have
            fallen under the disk, then record dropped ht (i.e. height of coop) as a number
            and check the box on the top layer indicating a coop is present.
       o If a point falls on a bedload sampler (square metal plate), call soil surface as "soil"
         and make a note in the notes section as to the point at which this occurred.
    Canopy and Basal Gap
       o Minimum Gap Size:  20cm
       o Include both perennials and annuals.

Quality assurance: 

      Date        Entry by                      QA/QC Description
     ----------  ----------------------------  ----------------------------------------------
     09/27/2012  John Anderson                 Entry program uses validation checks and pick lists.

Additional information: 

 GPS coordinates for associated research sites, include datum (WGS84 should be used where
    possible), projection and coordinate systems):
   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



Long-term dataset: 

Signature dataset: 

LTER Core Area(s): 

Data category: 

LTER VI Proposal Category: