PTN01 Aboveground net primary productivity along transects spanning topographic gradients on an annually burned and unburned watershed at Konza Prairie

Abstract:

In 1989, single transects spanning upland-lowland-upland topographic positions were established in a long-term unburned (0020B) and an annually burned (001D) watershed. Standing crop biomass data were collected in late season at 11 sites along each transect and sorted into live graminoids, forbs and woody plants, current year's dead, and previous years dead vegetation. Four 0.1 m2 quadrats were harvested at each of the 11 sites per watershed and all data except previous years' dead were combined to provide an estimate of aboveground NPP. In 1993, soil moisture measurements began along each transect at 15 and 30 cm depths (where possible) with a Time Domain Reflectomerty (TDR) system. Measurements were made twice a month from March - October and intermittently during the winter months.

Core Areas:

Data set ID:

Short name:

PTN01

Purpose:

To assess patterns in above ground biomass production and soil water content across topographic gradients in two watersheds: one annually burned and one unburned.

Methods:

Location of Sampling Stations: Cross-watershed transects were established in two watersheds in 1989, one annually burned (001D) and one unburned (020B). Transects were numbered west to east in an annually burned watershed (001D; grid S-25, S-26) and east to west in an unburned watershed (020B; grid N-29), see Fig. 21. Eleven sampling locations were located along each transect on both watersheds, and marked with 4-foot tall conduit markers. These positions were used for aboveground plant biomass sampling and measurements for soil water content. TDR probes were located adjacent to the conduit and used to estimate soil water content at 15 cm depths across the entire transects, and 30 cm depths where soil depth was sufficient (lowland sites).

Frequency of Sampling: Aboveground biomass was sampled, using standard LTER clipping methods, in late August-September from 1989-1997 (data are missing from 1992). Soil moisture was sampled approximately every two weeks during the growing season of 1993-1996. Discontinued September 1996.

Variable Measured: Total aboveground biomass per unit area and associated sub-categories as in PAB01. Soil moisture was measured by Time Domain Relectrometry (TDR).

Methods: Standing crop biomass data was collected in late season at 11 sites along each transect and sorted in to live graminoids, forbs and woody plants, current year's dead, and previous year dead vegetation. All data except previous years' dead are combined to provide an estimate of aboveground NPP. Four 0.1m2 quadrats were harvested at each of the 11 sites per watershed near the end of the growing season. Data for individual quadrats are reported for 1989 and 1991-1997. Data from 1990 are reported as mean values for each transect point location (see PTN01 metadata for more information on data formats). In 1993, soil moisture measurements began along each transect at 15 and 30 cm depths (where possible) using permanently installed probes and a portable Time Domain Reflectometry system. Soil moisture measurements were made at approximately two-week intervals from April-October.

For additional metadata information see: http://lter.konza.ksu.edu/sites/default/files/DC.pdf

For additional methods information see: http://lter.konza.ksu.edu/sites/default/files/MM.pdf