Stressor II transect line point intercept data

Data Access: 

Unrestricted

Dataset status: 

Study number: 

461

Data set ID: 

210461001

Date range: 

1996-02-27 to 2009-10-27

Original investigator: 

Kris Havstad

Abstract: 

The goal of this sampling effort is to describe the vegetation response to treatments.  Data were collected following the line-point intercept method (Herrick et al.

2009).  Although the original LPI data set was in multivariate form with separate columns for canopy layers and soil surface, this data set has been transposed into vertical form, implementing a “layer” variable, so that all species and soil surface codes appear in one column.  Within each exclosure, 4837 points were sampled with the following exceptions:

year

exclosure

total_points_sampled

1996

5

4825

1996

7

4836

1996

9

4836

1996

10

4836

1997

1

4830

1997

2

4830

1997

3

4830

1997

4

4830

1997

5

4830

1997

6

4830

1997

7

4830

1997

8

4830

1997

9

4830

1997

10

4830

1997

11

4830

1997

12

4830

1997

13

4830

1997

14

4830

1997

15

4830

1997

16

4830

1997

17

4830

1997

18

4830

2002

12

4835

 

Data download: 

Methods: 

Methods of recording

Field data sheets and field/tablet computers

Methodology

Data were collected following the line-point intercept method (Herrick et al. 2009).  Sampling has been conducted 4 times: in 1996, 1997, 2002, and 2009.  The 1996 sampling occurred before any treatments had been applied.  The 1997 sampling occurred after treatments had been applied once.  Treatment application stopped in 2000, so the 2002 and 2009 took place after treatments had been discontinued.  Each plot was sampled with 7 70 m transects, each running parallel and spaced 10 m apart.  On each transect, LPI data were collected at 10 cm intervals, beginning at 100 cm and generally ending at 7000 cm.  Transects were strung and sampled from the northeast side to the southwest side.  Treatment application was at the plot level, so each transect represents a subsample.  See “Multiple Stressor Site Exclosures – Layout.word.doc” for treatment scheme (note that the document includes Stressor I as well, which isn’t part of this data set).  Also see sampling notes in “StressorII LPI methods 2002.doc” and “StressorII LPI methods 2009.doc”

Quality assurance: 

 Data entry program validates entries for species code and acceptable range for cover. Visual validation for post-entry data.

Additional information: 

All data are from Stressor II, located in Pasture 9 near the southwest corner of Jornada Experimental Range.  The site is composed of 18 square plots (about 70 m x 70 m) fenced with barbed wire and arranged in a 9 x 2 grid that runs northwest to southeast.  In WGS84, UTM Zone 13N, the site boundaries are:

Corner    X coordinate         Y coordinate

North      326115.649147       3607532.037330

South     326467.761357       3606979.711190

East        326567.230873       3607079.337500

West      326014.308920       3607430.571700

Maintenance: 

Frequency of measurement

once per year in 1996, 1997, 2002, and 2009

Long-term dataset: 

Signature dataset: 

LTER Core Area(s): 

Data category: 

LTER VI Proposal Category: