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Methods for Experiment 014 -

Baseline information for abandoned farm fields

Note: a. Fields in which quadrats were located along the edge of unmanipulated control plots rather than on permanent transects. b. Sample size is 150 rather than 100. "Historical": Last cultivated date based on historical documents and personal accounts. "Aerial Photographs": Last cultivated date based on assessment in 1993 using a time series of aerial photographs.

Field Operations: Prescribed Burning

In 2006 each field was divided in half, and one half randomly chosen for periodic prescribed burning (approximately a fire every other year), see table below. All transects in Field 26 are excluded from burning.

Transect and Plot Information

Four permanent 40m long transects were laid out in each field, except for fields 22 and 29 where 6 transects were laid out (labeled A,B,C,D,E,F). The parallel transects were labeled green, red, white and yellow and placed in alphabetical order and 25m apart. In field 21, however, transects were not parallel to each other nor 25m apart. In this field transects ran along the edge of the treatment I macroplots described in E004. The "zero" end of a transect is the end where the green transect is on the left as you face the transects. Twenty-five quadrats (plots), 1 by 0.5 m, were permanently marked every 1.5m along each transect. The 0.5m side of the plot was parallel to the transect line. The first plot is 1.5m from the zero end of the transect. These plots were made permanent in 1993 and designated by rebars placed at 2 diagonal corners of the plot.

Burn Treatment: 1 = transect included in prescribed burn when applied, 0 = transect is not burned.

Transects E014 and Plots E054 - E054 is a separate experiment with plots located near the ends of E014 transects in some Old Fields as mapped in this schematic:

abwe014 - Supplemental Old Field Grasshopper Sampling

Supplemental Old Field Grasshopper Sampling

Approximately 20 old agricultural fields which were abandoned at various times make up the core of e014. In these core fields four permanent sampling transects were laid out in each field. Fields 22 and 29 have 6 transects but these fields are not generally considered part of the core group. In addition to these core old fields, many other similar abandoned fields exist at Cedar Creek and a subset was also sampled for grasshoppers. For the purpose of the grasshopper sampling these fields have been labeled as ?supplemental? old fields. The supplemental fields did not have permanent transects in them and grasshopper sampling methods were adjusted accordingly. Supplemental fields were sampled in such a way as to be complementary to the grasshopper sampling in the 21 core e014 old fields. Grasshoppers in the supplemental old fields were sampled by sweepnet mid-month from June through September from 1989-1992 and 1994-2006. Between 1989 and 1994 some fields were sampled inconsistently. See Table: Supplemental Old Fields Grasshopper Sampling, plots and dates. Three additional fields, 67, 537, 556, were also sampled in 1 year, 1990. In each sampling period, the supplemental fields received 100 sweeps per plot through a grid 40 x 75 meters in size (corresponds to size of the transect grid in the core old fields). The total number of sweeps for each field in each sample period was 100, with an annual total of 400 sweeps/field (ie half of the total sweeps in the core old fields). All sweeps were taken with a 15-inch muslin sweep net and each sweep consisted of a rapid approximately 2m-long horizontal swing of the net through the vegetation. Sweeps were generally collected between 10am-4pm during a two day period when it had not rained and weather was fair with sunny skies, modest breezes, and temperatures above 70?F. The samples were bagged in 1-gallon plastic bag and frozen until Orthoptera could be counted and identified to genus and species (where possible). All identifications were done by John Haarstad.*Note about comparing experiments: morphological notes may not indicate the same species/group in different experiments.

Supplemental Old Field Grasshopper Sampling: Data Preparation

Data preparation was begun by John Haarstad and others and completed by Colleen Satyshur by using the Arnett Codes John assigned and the matching taxonomic information from early subsets of data completed by John.

Supplemental Old Field Grasshopper: Sampling Irregularities

Irregularities to Note with Supplemental Old Field Grasshopper Sampling 1) All Orthoptera families were sorted and identified every time plots were sampled. 2) See detailed plot sampling schedule in Table: Supplemental Old Fields Grasshopper Sampling, plots and dates. 3) During the first three years of this study (1989-1991) John Haarstad was unable to distinguish several species of Melanoplus nymphs and they were lumped under the identification: ?Melanoplus undet nymphs?. No other serious difficulties in identification were encountered.

Table: Supplemental Old Fields Grasshopper Sampling, plots and dates

aihe014 - In situ soil N mineralization in gopher mounds and soil under gopher mounds

Instrumentation - lab

The ammonium-nitrogen NH₄+-N and nitrate-nitrogen NO₃--N were analyzed with QuikChem 8500 Series 2 FIA System (Lachat Instruments, Loveland, CO).

Sampling and lab analysis

In situ net N mineralization rates of gopher mound soil and the soil under mounds (0-20 cm) were determined in 6 of the 7 fields over the growing season in 2016, as no new gopher mounds were found in early spring in one of the fields. Four mounds and four locations in the undisturbed area were selected in each field. The in situ net N mineralization rates were measured twice: from late May to early July, and from early July to mid-August. At each mound, mound height was first measured (usually around 10 - 15 cm), then a PVC pipe (35 cm tall, 7.6 cm inner diameter) was inserted from the top of the mound until it reached 20 cm depth from the surrounding soil surface. The PVC pipe was loosely covered to allow gas exchange. Additional soil cores that corresponded to the same depths were collected adjacent to the PVC pipe to analyze for initial NH₄+-N + NO₃--N and total soil Carbon and Nitrogen. At the end of 5 weeks, soil samples were collected from PVC pipes and analyzed for final NH₄+-N + NO₃--N. 1 mol KCl solution was used to extract NH₄+-N + NO₃--N.

aiie014 - Aboveground biomass on and around gopher mounds 2017

Sampling

In August of 2017, aboveground biomass samples were collected on and adjacent to gopher mounds that were created in 2014, 2015, 2016 and 2017, and the undisturbed areas (with no apparent old mounds) in each of the 7 old fields. In each field, 8 gopher mounds were randomly selected for each age group (0, 1, 2, 3-year-old). At each mound, vegetation on the mound was collected in a quadrat that depends on the size of the mound, and the exact side length was recorded. Vegetation adjacent to the mound was collected in four 20 by 20 cm quadrat in 4 directions. In 8 randomly selected area within each field, vegetation samples were collected in 50 by 50 cm quadrats. Samples were sorted to litter and live biomass, dried and weighed.

ghe014 - Core Old Field Grasshopper Sampling

Core Old Field Grasshopper Sampling

Core Old Field Grasshopper Sampling Approximately 20 old agricultural fields which were abandoned at various times make up the core of e014. In these core fields four permanent sampling transects were laid out in each field. Fields 22 and 29 have 6 transects but these fields are not generally considered part of the core group. In addition to these core old fields, many other similar abandoned fields exist at Cedar Creek and a subset was also sampled for grasshoppers. For the purpose of the grasshopper sampling these fields have been labeled as ?supplemental? old fields. The supplemental fields did not have permanent transects in them and grasshopper sampling methods were adjusted accordingly. Grasshoppers in 19 core E014 old fields were sampled by sweepnet mid-month from June through September from 1989-2006. Field 28 was added in 1997 and field 11 was added in 2002, bringing the total core field count to 21. Sampling dates are summarized in Table: Core Old Fields Grasshopper Sampling, fields and dates. In each sampling period, 50 sweeps were taken with a 15-inch muslin sweep net along four 40m transects (labeled G, R, W, Y) near the center of each plot. The total number of sweeps for each field in each sample period was 200, with an annual total of 800 sweeps/field. A sweep consisted of a rapid approximately 2m-long horizontal swing of the net through the vegetation. Sweeps were generally collected between 10am-4pm during a two day period when it had not rained and weather was fair with sunny skies, modest breezes, and temperatures above 70?F. The contents for each transect were bagged separately in 1-gallon plastic bag, but counts in this data set are pooled by sampling period. Samples where frozen until Orthoptera could be counted and identified to genus and species (where possible). All identifications were done by John Haarstad. *Note about comparing experiments: morphological notes may not indicate the same species/group in different experiments.

Core Old Field Grasshopper Sampling: Data Preparation

Data preparation was begun by John Haarstad and others and completed by Colleen Satyshur by using the Arnett Codes John assigned and the matching taxonomic information from early subsets of data completed by John.

Core Old Field Grasshopper Sampling: Irregularities to Note

1) Only the family Acrididae was recorded throughout the entire survey period (1989-2006). Other families were sorted and identified in all years except 1992 and 1993. 2) Two newly abandoned fields were added to the core old field survey after it began in 1989. Field 28 was added in 1997 and field 11 was added in 2002. 3) In 2003, samples were lost from 7 fields in June (21, 24, 26, 27, 32, 39, 40) and 4 fields in August (47, 45, 53, 76). The total counts for these fields were augmented by proportional additions from remaining samples by John Haarstad and crew. 4) During the first three years of this study (1989-1991) John Haarstad was unable to distinguish several species of Melanoplus nymphs and they were lumped under the identification: ?Melanoplus undet nymphs?. No other serious difficulties in identification were encountered.

Table: Core Old Fields Grasshopper Sampling, fields and dates

lpe014 - Percent light penetration

Light Penetration

Light meter readings for E014 were taken in 1984 and 1989. In 1984, a pair of light meter readings was taken 10cm to the left (towards the transect) of the clipped strip, one reading at ground level and one reading above the vegetation. In 1989, a pair of light meter readings was taken in the middle of each plot, one at ground level and one above the vegetation. The light readings for E014 were taken between 8:00 A.M. and 5:00 P.M. (in 1989). There was not enough time to restrict the reading times to two hours before and after solar noon only on cloudless days. The light readings had to be done when the researchers were in the field. Shading due to clouds was avoided when possible, but readings were taken when the sky was completely (and uniformly) overcast.

Light Penetration Measurements

From 1982 to 1988, light meter readings were taken using a Li-Cor, Inc. Integrating Quantum/Radiometer/Photometer, model LI-188B. Two people were needed to take light readings with this system. One would hold the control box and record data and the other would hold the light sensor. The batteries would be checked before starting each session. If the batteries were OK, they would proceed to take readings. The sensor was connected to the control box by a relatively short cord, so the two people taking readings were required to stay close together. When taking readings, it was necessary to get a range value for each light value entered. If the integrating time of 1 second was not sufficient, it was increased to 10 seconds. This was also recorded. In 1989, two new light meters were acquired. These are SF Sunfleck Ceptometers, model SF-40 (40cm probe). They were purchased from Decagon Devices, Inc., P.O. Box 835, Pullman, WA 99163. One person can easily handle a ceptometer alone. This makes is possible for three people to get the readings done more quickly and easily. One person records data while the other two take readings from the plots simultaneously. No range values are needed. To take readings a person needs to select function #1 (PAR readings), position the probe (see below) and press ``A' (read value). More than one reading can be taken and then averaged by pressing a certain sequence of letters (A, A, B, B, A). Measurements are taken within a 4 hour period, 2 hours on either side of solar noon. (Solar noon is half way between sunrise and sunset; it is not 1200 hours). Solar noon is at 1315 hours, Central Daylight Time. Samples are taken between 1115 hours and 1515 hours. Measurements are not taken when the plot being sampled is shaded. Light readings are done when the sky is clear, whenever possible. If a cloud passes over the plot being sampled, assistants wait for the cloud to pass before taking the readings. If the sky is mostly cloudy, light meter readings are not taken. Two measurements are taken in each plot. Each measurement consists of one reading above the vegetation and a second reading at ground level. Both values are taken to get the percent of sunlight above the vegetation that reaches ground level. In taking the above vegetation reading, the sensor must be kept level, held high above all vegetation, kept out of the shade (of plants and people) and it must be clean. When taking the below vegetation reading, at ground level, the sensor must be kept level, out of the soil and out of the shade created by people. In 1991, light meter readings were only taken in E026 and E055. Light profiles were taken using an A-shaped frame made of aluminum. Wires were strung across the frame at 10cm intervals. The frame was placed over the subplot being metered. A reading was taken over the top of the frame, and then at each 10cm level, by placing the light meter across the wires, starting at 90cm above the ground. Readings were taken every 10cm down the frame and again at ground level. Light Data Transformations: Light readings are transformed to obtain percent light penetration which represents the percent of light above the vegetation that reaches the ground surface. In cases where the experiment involves shading, another variable is computed to reflect the percent of sun light that reaches above the canopy. This variable is called light available. In the case of absence of artificial shades, the latter is set to 1. percent light penetration = ( Light below canopy / Light above canopy ). percent light available = ( Light below shade / Light above shade ).

mre014 - Nitrogen mineralization rate

Soil sampling

In 1983 soil cores were taken at the center of each plot that was censused for percent cover. The first and last plots in each of the 4 transects in each field were cored to a depth of 60cm and subdivided into 0-5cm 5-10cm 10-20cm 20-40cm and 40-60cm. All other plots were cored to a depth of 10cm. Bags were marked with the depth, field, transect, plot and date sampled. The bags were placed in a drying oven. The contents were analyzed for total nitrogen content, nitrogen mineralization and pH. In 1984 a soil core was taken in the center of each clipped strip. The cores were divided into 0-10, 10-20, and 20-30cm fractions, bagged separately, and frozen until they were analysed. (I have no data.) In 1985 soil samples were analyzed for total nitrogen and carbon. In 1986 soil samples were analyzed for available nitrogen and nitrogen mineralization. In 1989 contrary to web was soil sampled or was 1983 data reanalyzed (total N and C)? In 1995 soil samples were analyzed for available nitrogen and nitrogen mineralization.

mse014 - Small mammal abundance

Small mammal abundance

In 1984 small mammals were trapped. Snap traps were baited with oatmeal/peanut butter and a trap placed at each stake (0, 10, 20, 30, 40, 50m). All transects in 1 field were trapped on the same night. One trapping session for 1 field consisted of 3 consecutive nights of trapping. Fields were trapped twice (2 sessions) in August and once in September.

ne014 - Soil nitrogen

Soil sampling

In 1983 soil cores were taken at the center of each plot that was censused for percent cover. The first and last plots in each of the 4 transects in each field were cored to a depth of 60cm and subdivided into 0-5cm 5-10cm 10-20cm 20-40cm and 40-60cm. All other plots were cored to a depth of 10cm. Bags were marked with the depth, field, transect, plot and date sampled. The bags were placed in a drying oven. The contents were analyzed for total nitrogen content, nitrogen mineralization and pH. In 1984 a soil core was taken in the center of each clipped strip. The cores were divided into 0-10, 10-20, and 20-30cm fractions, bagged separately, and frozen until they were analysed. (I have no data.) In 1985 soil samples were analyzed for total nitrogen and carbon. In 1986 soil samples were analyzed for available nitrogen and nitrogen mineralization. In 1989 contrary to web was soil sampled or was 1983 data reanalyzed (total N and C)? In 1995 soil samples were analyzed for available nitrogen and nitrogen mineralization.

ome014 - Soil organic matter

Soil sampling

In 1983 soil cores were taken at the center of each plot that was censused for percent cover. The first and last plots in each of the 4 transects in each field were cored to a depth of 60cm and subdivided into 0-5cm 5-10cm 10-20cm 20-40cm and 40-60cm. All other plots were cored to a depth of 10cm. Bags were marked with the depth, field, transect, plot and date sampled. The bags were placed in a drying oven. The contents were analyzed for total nitrogen content, nitrogen mineralization and pH. In 1984 a soil core was taken in the center of each clipped strip. The cores were divided into 0-10, 10-20, and 20-30cm fractions, bagged separately, and frozen until they were analysed. (I have no data.) In 1985 soil samples were analyzed for total nitrogen and carbon. In 1986 soil samples were analyzed for available nitrogen and nitrogen mineralization. In 1989 contrary to web was soil sampled or was 1983 data reanalyzed (total N and C)? In 1995 soil samples were analyzed for available nitrogen and nitrogen mineralization.

pce014 - Plant species percent cover data

Vegetation Sampling

Percent cover of vegetation, bare ground and litter has been estimated for every plot approximately every five years, starting in 1983. The vegetation cover has been recorded for each species. In 1989 estimates of cover were performed in all plots except that the only plots surveyed in field 22 were plots 1 to 19 in transects A(1) and B(2) and the only plots surveyed in field 69 were plot 1-10 in transects 1, 2, 3, 4. Since 1994 fields 22(B), 29(A) and 69(C) have been excluded. In 1983 the number of Oenothera plants in each plot was recorded. In 1984 the height of the tallest plant within a 50cm radius circle at 0, 10, 20, 30, 40, and 50 m along each transect was recorded. Aboveground biomass was collected in 1984. A 1m by 10cm strip was clipped 1 meter to the right of the transect from 9-10m, 19-20m and 29-30m. The biomass was sorted to grasses, forbs and litter, dried and weighed.

phe014 - Soil pH

Soil sampling

In 1983 soil cores were taken at the center of each plot that was censused for percent cover. The first and last plots in each of the 4 transects in each field were cored to a depth of 60cm and subdivided into 0-5cm 5-10cm 10-20cm 20-40cm and 40-60cm. All other plots were cored to a depth of 10cm. Bags were marked with the depth, field, transect, plot and date sampled. The bags were placed in a drying oven. The contents were analyzed for total nitrogen content, nitrogen mineralization and pH. In 1984 a soil core was taken in the center of each clipped strip. The cores were divided into 0-10, 10-20, and 20-30cm fractions, bagged separately, and frozen until they were analysed. (I have no data.) In 1985 soil samples were analyzed for total nitrogen and carbon. In 1986 soil samples were analyzed for available nitrogen and nitrogen mineralization. In 1989 contrary to web was soil sampled or was 1983 data reanalyzed (total N and C)? In 1995 soil samples were analyzed for available nitrogen and nitrogen mineralization.

Soil sampling

In 1983 soil cores were taken at the center of each plot that was censused for percent cover. The first and last plots in each of the 4 transects in each field were cored to a depth of 60cm and subdivided into 0-5cm 5-10cm 10-20cm 20-40cm and 40-60cm. All other plots were cored to a depth of 10cm. Bags were marked with the depth, field, transect, plot and date sampled. The bags were placed in a drying oven. The contents were analyzed for total nitrogen content, nitrogen mineralization and pH. In 1984 a soil core was taken in the center of each clipped strip. The cores were divided into 0-10, 10-20, and 20-30cm fractions, bagged separately, and frozen until they were analysed. (I have no data.) In 1985 soil samples were analyzed for total nitrogen and carbon. In 1986 soil samples were analyzed for available nitrogen and nitrogen mineralization. In 1989 contrary to web was soil sampled or was 1983 data reanalyzed (total N and C)? In 1995 soil samples were analyzed for available nitrogen and nitrogen mineralization.

she014 - Shrub data

Woody transect methods for E014 (2006)

In each of the E14 old fields, two belt transects were established running parallel to the permanent percent cover plots, one passing between transects 1 and 2 and the other between 3 and 4. Each transect is 4 m wide and runs from one edge of each old field to the other, as determined by the presence of mature trees or other boundaries (such as roads). A blue-painted post was placed on one end of the field, then approximately every 50 m along the transect with an additional post marking the end of the transect if necessary. When conducting the survey, a tape measurer was stretched taughtly between these posts in order to mark the center of the transect and the distance along it. As the crew walked each transect, one person carried a 4 m long pole, held centered over the tape measurer and marked with 10 cm increments. This pole was used to estimate the position of trees within the width of the transect, with 0.0 representing the far left side of the transect and 4.0 indicating the far right side. This was the first year of this survey, and there was quite a bit of variation in numbering and orientation of the transects. Consult the plot map (following page) for details. Numbers used for naming the transects are indicated on the map, as are the directions in which transects were surveyed (distance along transect increases in the direction of each arrow). Also note that field 26 was not sampled in 2006. Tree survey: Within each transect, all woody individuals taller than breast height (1.3 m) were tagged, measured, and their position within the transect recorded. Individuals above BH but too small to have a nail hammered in were tag with wire. DBH was either measured with calipers or a DBH tape, depending on the size of the stem. If an individual branched belowground, all stems were tagged and measured separately. If a single stem was forked (split into two main stems) below BH, two DBH measurements were recorded. In a few instances a large, single-species clump (20+ stems above BH within a relatively small area) was encountered. In such cases the total number of stems above BH was noted, but only 10% of individuals (randomly selected) were tagged and measured. Shrub survey: Within each 10 m long section of the transect, the number of woody stems below breast height (1.3 m) was estimated for each species present. Stem counts were reported as abundance categories (1:1-5 stems within sample area, 2:6-40 stems, 3:>40 stems). Because transect lengths were not necessarily multiples of 10 meters, the last section of transect sampled was often not exactly 10 m long (stems were only counted if they fell within the transect). In cases where this last section was substantially different from 20 m long, the actual ending point of the transect was noted in the data. A few technically woody species (vines, subshrubs) were not included in the survey. These species are listed below: /Amorpha canescens/ /Ceanothus americana/ /Celastrus scandens/ /Parthenocissus vitacea/ /Rhus radicans/ /Ribes spp./ /Rosa// spp./ /Rubus spp./ /Spiraea spp./ /Vaccinium angustifolium/ /Vitis riparia/