EJR01 Foraging decisions underlying restricted space-use: effects of fire and forage maturation on large herbivore nutrient uptake on Konza Prairie

Summary

Short name: 

EJR01

Abstract: 

Recent models suggest that herbivores optimize nutrient intake by selecting patches of low to intermediate vegetation biomass. We assessed the application of this hypothesis to plains bison (Bison bison) in an experimental grassland managed with fire by estimating daily rates of nutrient intake in relation to grass biomass and by measuring patch selection in experimental watersheds in which grass biomass was manipulated by prescribed burning. Digestible crude protein content of grass declined linearly with increasing biomass, and the mean digestible protein content relative to grass biomass was greater in burned watersheds than watersheds not burned that spring (intercept; F1,251 = 50.57, P < 0.0001). Linking these values to published functional response parameters, ad libitum protein intake, and protein expenditure parameters, Fryxell's (Am. Nat., 1991, 138, 478) model predicted that the daily rate of protein intake should be highest when bison feed in grasslands with 400–600 kg/ha. In burned grassland sites, where bison spend most of their time, availability of grass biomass ranged between 40 and 3650 kg/ha, bison selected foraging areas of roughly 690 kg/ha, close to the value for protein intake maximization predicted by the model. The seasonal net protein intake predicted for large grazers in this study suggest feeding in burned grassland can be more beneficial for nutrient uptake relative to unburned grassland as long as grass regrowth is possible. Foraging site selection for grass patches of low to intermediate biomass help explain patterns of uniform space use reported previously for large grazers in fire-prone systems.

This data set was used to test the forage maturation hypothesis in the Konza Prairie bison enclosure from 2012-2013. Our objectives were to quantify foraging site selection of Plains bison in order to determine if bison in a fire-prone grassland selected sites of low-to-intermediate forage biomass as posited by Fryxell’s (1991) forage maturation hypothesis. Additionally, to understand how foraging patterns shifted when grass regrowth was not possible, we quantified the annual diet of four GPS-collared bison via stable isotope analysis of tail hair plucked during roundup.

DOI: 

10.6073/pasta/830c75a07a9adb9d8bfb7aade8659d50

Data set ID: 

400

Data sources: 

Variables: 

DataCode
  • Label:
  • Definition: Dataset Code
  • Type: Nominal
  • Missing values: None specified
RecType
  • Label:
  • Definition: Record Type
  • Type: Nominal
  • Missing values: None specified
Recyear
  • Label:
  • Definition: Year that data was collected
  • Type: Physical quantity
  • Unit: Year (YYYY)
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
RecMonth
  • Label:
  • Definition: Month that data was collected
  • Type: Nominal
  • Missing values: None specified
RecDate
  • Label:
  • Definition: Date that data was collected
  • Type: Date/time
  • Date format: MM:DD:YYYY
  • Missing values: None specified
DaysSinceMay1
  • Label:
  • Definition: The number of days since 1 May of that year
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Strata
  • Label:
  • Definition: sample group
  • Type: Nominal
  • Missing values: None specified
Status
  • Label:
  • Definition: On for grazed site, Off for site not grazer during observation
  • Type: Nominal
  • Missing values: None specified
Biomass
  • Label:
  • Definition: Dried biomass(averaged across three sub-plots) of all vegetation in 0.1 m2 clipping extrapolated to g/m2
  • Type: Physical quantity
  • Unit: gramsPerSquareMeter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
CP
  • Label:
  • Definition: Graminoid crude protein content derived from NIRS analysis, percentage
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
DCP
  • Label:
  • Definition: Graminoid adjusted crude protein content derived from NIRS analysis
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Watershed
  • Label:
  • Definition: Name of bison watershed that sample was collected
  • Type: Nominal
  • Missing values: None specified
Green
  • Label:
  • Definition: Percentage of green of all vegetation in plot (averaged)
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Grass
  • Label:
  • Definition: Percentage of grass in plot (averaged).
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Forbs
  • Label:
  • Definition: Percentage of forbs in plot (averaged).
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Litter
  • Label:
  • Definition: Percentage of litter in plot (averaged)
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Burn
  • Label:
  • Definition: Whether or not watershed burned that spring
  • Type: Nominal
  • Missing values: None specified
Grassweight
  • Label:
  • Definition: Mass of 0.1 g/m2 grass clippings extrapolated to g m2 for use in FMH simulation.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified

Variables: 

DataCode
  • Label:
  • Definition: Data set Code
  • Type: Nominal
  • Missing values: None specified
RecType
  • Label:
  • Definition: Record Type
  • Type: Nominal
  • Missing values: None specified
RecYear
  • Label:
  • Definition: Year that data was collected
  • Type: Physical quantity
  • Unit: Year (YYYY)
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Animal
  • Label:
  • Definition: animal ear tag number
  • Type: Nominal
  • Missing values: None specified
Increment_fr_follicle
  • Label:
  • Definition: increment is section of hair analyzed
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
d13C
  • Label:
  • Definition: Value of d13C from the segement analyzed.
  • Type: Nominal
  • Missing values: None specified

Categories

Core Areas: 

Dates

Date Range: 

Sunday, April 1, 2012 to Tuesday, December 31, 2013

Publication Date: 

Tuesday, August 30, 2016
People

Owner/Creator: 

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