plants

Dataset: 

Study number: 

11

Data set ID: 

210011003

Date range: 

1990-01-01 to 2015-12-31

Original investigator: 

Laura Huenneke

Data contact: 

Abstract: 

Summarizes mean aboveground net primary production, in g/m2/yr, by year for each of 15 sites. Annual totals derived by summing seasonal production values for winter (October - February), spring (February - May), and fall (May - October) increments for a single calendar year.

Please refer to these publications to evaluate the appropriateness of these data for your intended use prior to contacting Debra Peters, Responsible Investigator, with a data request.

Attention: These data are not appropriate for estimates of percentage cover. NPP-associated percent cover measurements were developed for and are used solely to provide the best estimate of biomass production. Becuase the methodology results in measurements of overlapping subcanopy systems and canopies of adjacent individuals, NPP percent cover measurements are not an appropriate measure of actual aerial plant cover. Doing so will result in inflated numbers for the "actual" vegetative cover.

Attention: Data through 2003 was replaced online per below on 9/22/2011. Analyses and results for ANPP differ from previous uses of the data from 1989-1998 (Huenneke et al., 2002) in three ways: (1) Yucca elata was removed prior to analysis because its growth form results in large errors in biomass estimates from year-to-year, (2) regressions between biomass and plant volume used an intercept equal to 0 to be consistent with a recent study in a similar system (Muldavin et al., 2008), and (3) reference harvests obtained in extreme years resulted in adjusted regression coefficents through time that reflect year-to-year variation in ANPP. These changes result in ANPP values that are smaller compared (Peters et al. submitted) with previous studies (Huenneke et al., 2002).

Data download: 

Description: 

LTER Core Area(s): 

Dataset: 

Study number: 

11

Data set ID: 

210011002

Date range: 

1989-05-09 to 2015-09-21

Original investigator: 

Laura Huenneke

Data contact: 

Abstract: 

Standing biomass is sampled three times a year: in winter (February - March), before shrubs begin spring growth; in spring (May), when shrubs and spring annuals have reached peak biomass; in fall (late summer; October), when summer annuals have reached peak biomass but before killing frosts.

At each sample date, each site is visited (order of sampling may vary, according to phenological stage of sites) and the dimensions of each plant on each quadrat are measured and recorded. Recorded for each observation are: date, zone, plot, quadrat #, species (4 letter acronym), observation # (one for each measurement of that species in that quadrat), cover (percentage of quadrat covered by canopy of that individual or species), height (vertical extent of that individual or species), count (if multiple individuals with the same dimensions are present), and phenological stage (Flowering/fruiting or Vegetative). Attention: These data are not appropriate for estimates of percentage cover. NPP-associated percent cover measurements were developed for and are used solely to provide the best estimate of biomass production. Becuase the methodology results in measurements of overlapping subcanopy systems and canopies of adjacent individuals, NPP percent cover measurements are not an appropriate measure of actual aerial plant cover. Doing so will result in inflated numbers for the "actual" vegetative cover.

Data download: 

Description: 

<p>Data file information for the following Jornada data set: NPP Study: Quadrat field measurement data</p>

LTER Core Area(s): 

Keywords: 

Dataset: 

Study number: 

28

Data set ID: 

210287001

Date range: 

1992-07-15 to 2015-12-15

Original investigator: 

Laura Huenneke

Data contact: 

Abstract: 

The phenological stage of all perennial plant species on the 15 NPP sites is recorded on a monthly basis. This allows us to track the influence of weather and of site differences on plant reproduction.

The boundaries of the (80m x 80m) study plot are walked and each individual plant of any perennial species in a 1-m belt is examined and its phenology noted (non-reproductive, in bud, in flower, in fruit, or dormant).

Data download: 

Description: 

Data file information for the following Jornada data set: Plant phenology transect at NPP sites

LTER Core Area(s): 

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