{EML Metadata} {Description of the Data file structure is available at the Niwot Ridge LTER Data page}

\log

The documentation section of this file was created by Mariah Carbone 
on 17 May 2001.  Additional comments were added to the file by Tim 
Seastedt on 18 May 2001.  Original documentation information was 
provided by Tim Seastedt in an email message to Michael Hartman on 
27 December 1997. This file was put under sccs control on 30 May 
2001.[TMA 30 May 2001]

\doc

TITLE.  Aspen Stand Litterfall.

ABSTRACT. This measurement was established in summer 1996, in response 
to the observation by Mark Losleben that the aspen foliage dynamics 
appeared to exhibit a very sensitive response to climate, particularly 
duration of snowpack. Aspen production, as indexed by litterfall, was 
suggested to be an important integrator and/or response function to 
climatic variability. Also, these data provide a minimum estimate of 
aboveground NPP of aspen stands in the Colorado Front Range, a data 
set of interest in relation to similar measurements obtained for the 
alpine tundra above these sites.

INVESTIGATOR. Tim Seastedt, INSTAAR, CB 450, University of Colorado, 
Boulder, CO, (303) 492-3302 Timothy.Seastedt@Colorado.Edu

VARIABLES.  Aspen, leaves, buds, wood, bark, needles and cones.

KEYWORDS.  Aspen stand, aspen leaves, buds, wood, bark, needles, 
cones, npp, net primary productivity.

LOCATION.  Five basic study areas for the 27 traps are located in 
the general area surrounding the Mountain Research Station.  All 
bearings are based on true north.  Most traps have GPS coordinates 
given in parentheses (easting, northing).
Location 1: from west side highway pullout with forest service gate, 
3/4 mile south of MRS road, north of Switzerland Trail.
Trap 1, just off highway pullout.
Trap 2, past gate, down the road 400m, 50ft off west side of road. 
(455869.364,4430497.679)
Trap 3, across Como Creek 75m, north (right) off road 50m.
Trap 4, across Como Creek, continue up road to Switzerland Trail, 
then 45 paces at 310 degrees, then 40 paces at 220 degrees. (455621.208,
4430399.483)
Trap 5, 40 paces at 310 degrees from Trap 4.
Trap 6, 63 paces at 277 degrees from Trap 5. (455541.671,4430430.532)
Location 2: from road junction of MRS and Rainbow Lakes road.
Trap 7, 40 paces at 168 degrees from MRS/Rainbow Lakes road sign. 
(454706.613,4431068.917)
Trap 8, 79 paces at 117 degrees from MRS/Rainbow Lakes road sign. 
(454758.584,4431055.981)
Trap 9, 32 paces at 278 degrees from MRS/Rainbow Lakes road sign. 
(454679.434,4431112.085)
Trap 10, 40 paces west from gate on Rainbow Lakes road then 49 paces 
at 124 degrees. (454674.265,4431032.538)
Trap 11, 38 paces at 264 degrees from Trap 10. (454641.855,4431030.954)
Trap 12, 12 paces at 56 degrees from CU-MRS sign. (454707.697,
4431134.308)
Location 3: 400 paces up Rainbow Lakes road from gate.
Trap 13, 10 paces east of road. (454548.102,4430815.764)
Trap 14, 42 paces at 162 degrees from Trap 13. (454558.083,4430781.310)
Trap 15, 30 paces at 150 degrees from Trap 14. (454572.427,4430761.725)
Trap 16, 34 paces at 129 degrees from Trap 15. (454594.349,4430744.367)
Trap 17, 38 paces at 289 degrees from Rainbow Lakes road opposite Trap 
13. (454512.686,4430827.271)
Location 4: porch of Tularosa cabin (S-cabins).
Trap 18, 33 paces at 115 degrees from porch. (454135.276,4431245.405)
Trap 19, 62 paces at 218 degrees from porch. (454097.378,4431220.481)
Trap 20, 37 paces at 186 degrees from Trap 19. (454086.610,4431196.353)
Trap 21, 66 paces at 224 degrees from Trap 20. (454057.518,4431172.601)
Trap 22, 49 paces at 286 degrees from Trap 21. 
Trap 23, 150m east of C-1, 10 paces north of road. (453744.814,4431853.144)
Location 5: Old trail west of power line.
Trap 24, 10 paces north of Hills Cabin, south of Niwot Ridge road. 
(453889.168,4431718.485)
Trap 25, 100 paces south on trail past Trap 24. (453833.402,4431674.441)
Trap 26, 120 paces south on trap from Trap 25, 3 paces west of trail. 
(453831.280,4431597.866)
Trap 27, 120 paces south-southeast on trail past Trap 26, 5 paces south 
of trail. (453882.294,4431557.223)

TIMING.  Traps were initially established in summer 1996.  The first 
collection date was October 1996.  Collections took place twice a 
year (July and October) from 1997 through 1999.

CITATIONS. 

COMMENTS. Initially, 27 litterfall traps, 50cm * 50cm (0.25m2) were 
constructed and placed into the field in summer 1996.  Litter from 
each trap was obtained, dried at about 70C for two days, sorted into 
three categories, leaves and buds, wood and bark, and other (largely 
conifer needles and cones) and weighed. No data are collected from 
damaged collectors, and users of these data must be careful not to 
use collectors with missing values in annual estimates.
Field notes are as follows:
961015, Trap 15 knocked over, probably spilled most contents.
970702, Trap 7 flashing destroyed (removed).
970702, Trap 21 surrounded by tall flowers.
970702, Trap 22 flooded and removed.
970702, Trap 23 1 large stick collected.
971022, Trap 1 moved and damaged by hikers?  Repaired and set near 
original location.
971022, Trap 3 destroyed, removed.
980709, Trap 1 removed.

\type

statistical.

\header

COL1. label=Collection date, type=string, units=yymmdd, missing value 
indicator=, minimum=961015, maximum=991014, precision=

COL2. label=Trap ID, type=string, units=none, missing value indicator=, 
minimum=01, maximum=27, precision=

COL3. label=Aspen leaves and buds, type=string, units=grams, missing 
value indicator=., minimum=0.05, maximum=53.01, precision=.01

COL4. label=Aspen wood and bark, type=string, units=grams, missing value 
indicator=., minimum=0, maximum=32.00, precision=.01 

COL5. label=Other (conifer needles and cones), type=string, units=grams, 
missing value indicator=., minimum=0, maximum=5.99, precision=.01

{*********************************************************************

If the data section below contains no data then you will need to 
obtain permission from the investigator listed in the documentation 
section of this file. If you have obtained permission or if the data 
are already contained in this file, include the following 
acknowledgment (in addition to an acknowledgment of the investigator)
in any published use of these data: "Logistical support 
and/or data were provided by the Niwot Ridge Long-Term Ecological 
Research project (NSF DEB 0423662) and the Mountain Research Station 
(BIR 9115097)." Please send 4 reprints or high-quality copies of any
such publications to Todd Ackerman, NWT LTER data manager, 
INSTAAR, CB 450, University of Colorado, Boulder, CO, 80309-0450.
The data contained in these files have many sources. Generally,
data collected prior to 1993 would have been subjected to quality
control standards imposed by the investigator. Data after 1992 
were likely to have been manually entered and/or processed in the
NWT LTER central data management laboratory. Detailed information
on the quality control protocols and programs associated with any
data routed through the NWT LTER data management laboratory will 
be supplied upon request. The user of these data should be aware
that, while efforts have been taken to ensure that these data are 
of the highest quality, there is no guarantee of perfection for
the data contained herein and the possibility of errors exists.
If you encounter questionable data, please contact the NWT LTER
data manager (todda@culter.colorado.edu; (303) 492-4771) so that
the data can be corrected or qualified. Thus, these data should
be considered dynamic in that past data may be modified and future
data will be appended.

******************************************************************}

\data

961015,01,14.68,4.49,4.83
961015,02,12.26,11.41,0.65
961015,03,18.52,9.39,0.01
961015,04,12.73,8.67,
961015,05,14.92,7.88,
961015,06,15.11,11.59,
961015,07,25.23,2.86,
961015,08,13.58,2.27,0.52
961015,09,23.47,2.89,0.53
961015,10,8.63,1.19,0.08
961015,11,8.21,0.34,0.03
961015,12,12.67,3.6,1.82
961015,13,30.24,2.67,0
961015,14,24.51,0.81,0.16
961015,15,15.97,0.51,0.04
961015,16,18.67,1.3,0.05
961015,17,17.06,2.16,0.9
961015,18,6.3,0.39,3.71
961015,19,7.49,1.41,0.65
961015,20,12.35,8.09,0.45
961015,21,23.22,5.46,0.17
961015,22,21.81,5.52,0.41
961015,23,11.77,0.44,1.25
961015,24,10.39,1.87,1.27
961015,25,13.45,1.32,0.2
961015,26,25.39,0.39,0.52
961015,27,12.03,1.27,0.41
970702,01,0.78,2.45,5.99
970702,03,0.59,3.22,0.14
970702,04,0.7,1.2,0.04
970702,05,0.66,0.04,
970702,06,0.82,1.95,
970702,07,0.19,3.46,
970702,08,0.84,1.24,0.31
970702,09,0.12,1.17,1.7
970702,10,0.17,1.94,0.05
970702,11,0.25,0.22,0.15
970702,12,0.76,2.19,1.77
970702,13,1.7,1.34,0.25
970702,14,0.7,0.24,0.09
970702,15,0.05,0.91,0.06
970702,16,1.34,1.1,0.15
970702,17,0.49,2.36,1.06
970702,18,0.33,,3.14
970702,19,0.28,1.19,2.41
970702,20,,2.23,1.15
970702,21,,2.42,0.41
970702,23,0.1,17.11,3.31
970702,24,0.21,0.31,0.57
970702,25,0.42,4.18,0.23
970702,26,3.88,0.57,0.65
970702,27,0.92,0.03,1.46
971022,01,0.33,0,0.59
971022,02,31.44,5.74,0.69
971022,04,41.17,0.25,0
971022,05,27.96,1.6,0
971022,06,44.31,0.65,0
971022,07,37.69,10.86,
971022,08,26.69,6.44,3.89
971022,09,40.08,2.12,2.07
971022,10,15.38,1.19,0
971022,11,15.87,1.12,0
971022,12,29.17,1.65,1.33
971022,13,53.01,15.68,0.03
971022,14,48.17,2.4,0.04
971022,15,43.15,10.13,0
971022,16,42.22,1.47,0.05
971022,17,31.37,4.75,1.15
971022,18,10.46,0.47,2.47
971022,19,16.15,0.39,0.5
971022,20,24.18,1.75,0.17
971022,21,51.58,10.91,0.15
971022,23,30.46,3.16,0.63
971022,24,25.2,0.81,0.31
971022,25,28.05,4.5,0.15
971022,26,34.9,9.66,0.13
971022,27,23.91,2.34,0.54
980709,02,1.17,1.98,0.89
980709,04,0.18,0.99,0.05
980709,05,0.67,0.4,
980709,06,1.24,0.57,0.07
980709,07,1.94,7.6,
980709,08,0.89,1.49,0.88
980709,09,1.54,3.43,2.09
980709,10,0.88,0.15,0.07
980709,11,0.54,1.01,0.35
980709,12,0.52,1.34,2.32
980709,13,0.95,1.71,0.19
980709,14,0.91,5.6,0.09
980709,15,0.69,3.62,0.16
980709,16,1.84,1.88,0.17
980709,17,0.63,0.84,1.53
980709,18,1.61,0.26,4.48
980709,19,3.07,0.99,1.84
980709,20,1.08,1.76,1.18
980709,23,1.74,2,2.01
980709,24,2.07,2.16,2.57
980709,25,2.41,3.92,0.44
980709,26,2.63,1.37,0.55
980709,27,2.41,1.21,4.51
981022,02,35.45,1.28,0.5
981022,04,43.2,19.64,0
981022,05,19.9,1.65,0
981022,06,35.76,4.3,0
981022,09,31.06,2.57,0
981022,10,10.4,0.61,0
981022,11,6.98,1.47,0.12
981022,12,21.65,0.1,1.8
981022,13,46.57,2.76,0
981022,14,35.6,3.61,0.1
981022,15,37.54,3.44,0
981022,16,32.33,9.47,0
981022,18,3.88,0.1,1.91
981022,19,7.17,1.08,0.87
981022,20,13.68,0.9,0.22
981022,21,30.94,6.4,0.9
981022,22,37.21,0.14,0
981022,23,17.44,4.53,0.25
981022,24,13.13,0.79,0.16
981022,25,15.5,1.49,0
981022,26,17.91,2.49,0.14
981022,27,12.47,0.9,0.49
990702,02,0.76,1.28,1.15
990702,04,0.92,3.65,0
990702,05,0.42,3.4,0
990702,06,1.27,3.05,0
990702,07,1.32,32,0.09
990702,08,0.75,4.41,1.32
990702,09,2.47,10.68,5.02
990702,10,0.26,0.71,0.29
990702,11,0.46,0.93,0.19
990702,12,1.22,23.92,2.41
990702,13,2.78,10.66,0.36
990702,14,1.43,14.14,0.44
990702,15,1.91,30.9,0.2
990702,16,1.83,7.68,0.41
990702,17,1.35,4.87,2.43
990702,18,0.29,0.56,4.23
990702,19,0.58,2.44,4.28
990702,20,0.7,1.52,2.45
990702,21,2.81,6.02,2.39
990702,23,0.64,5.44,1.26
990702,24,0.29,0.34,1.2
990702,25,0.36,28.64,0.26
990702,26,1.11,0.71,0.37
990702,27,0.64,1.56,0.88
991014,02,17.33,2.19,0.4
991014,04,33.05,2.73,0.3
991014,05,24.37,9.08,0.1
991014,06,38.01,3.08,0.03
991014,07,34.74,3.14,0
991014,08,25.03,1.47,3.88
991014,09,9.21,0.51,0.33
991014,10,8.67,0.8,0.21
991014,11,8.54,1.15,0
991014,12,25.3,0.3,2.8
991014,13,50.51,5.27,0.17
991014,14,32.71,8.31,0.46
991014,15,40.56,2.21,0.95
991014,16,32.5,2.56,0.57
991014,17,26.54,1.05,1.33
991014,18,11.25,0.95,0.23
991014,19,9.3,2.5,1.48
991014,20,46,1.3,0.2
991014,21,13.4,5.35,1.2
991014,23,27.89,5.36,0.61
991014,24,18.01,1.35,0.17
991014,25,32.3,2.03,0.35
991014,26,39.52,2.57,1.89
991014,27,23.02,1.33,0.25