KKE03 The Konza-Kruger Experiment: Kruger species composition (2006-2010)

Summary

Short name: 

KKE03

Abstract: 

The distribution, structure and function of mesic savanna grasslands are strongly driven by fire regimes, grazing by large herbivores, and their interactions. This research addresses a general question about our understanding of savanna grasslands globally: Is our knowledge of fire and grazing sufficiently general to enable us to make accurate predictions of how these ecosystems will respond to changes in these drivers over time? Some evidence suggests that fire and grazing influence savanna grassland structure and function differently in South Africa (SA) compared to North America (NA). These differences have been attributed to the contingent factors of greater biome age, longer evolutionary history with fire and grazing, reduced soil fertility, and greater diversity of plants and large herbivores in SA. An alternative hypothesis is that differences in methods and approaches used to study these systems have led to differing perspectives on the role of these drivers. If the impacts of shared ecosystem drivers truly differ between NA and SA, this calls into question the generality of our understanding of these ecosystems and our ability to forecast how changes in key drivers will affect savanna grasslands globally. Since 2006, an explicitly comparative research program has been conducted to determine the degree of convergence in ecosystem (productivity, N and C cycling) and plant community (composition, diversity, dynamics) responses to fire and grazing in SA and NA. Thus far, initial support has been found for convergence at the ecosystem level and divergence at the community level in response to alterations in both fire regimes and grazing. However, there have also been two unexpected findings (1) the ways in which fire and grazing interact differed between NA and SA, and (2) the rate of change in communities when grazers were removed was much greater in NA than in SA. These unexpected findings raise a number of important new questions: (Q1) Will exclusion of grazing eventually affect community structure and composition across all fire regimes in SA? (Q2) Will these effects differ from those observed in NA? (Q3) What are the determinants of the different rates of community change? (Q4) How will these determinants influence future trajectories of change? (Q5) Will the different rates and trajectories of community change be mirrored by responses in ecosystem function over time? This project is based on a large herbivore exclusion study established within the context of long-term (25-50+ yr) experimental manipulations of fire frequency at the Konza Prairie Biological Station (KPBS) in NA and the Kruger National Park (KNP) in SA. The suite of core studies and measurements include plant community composition, ANPP, and herbivore abundance and distribution at both study sites to answer these research questions.

Published on EDI/LTER Data Portal

Citation Suggestion: 

Blair, J. M., Collins, S. L., Knapp, A. K., Smith, M. D. 2019. KKE03 The Konza-Kruger Experiment: Kruger species composition (2006-2010) . Environmental Data Initiative. http://dx.doi.org/0.6073/pasta/7d9467fe079f7dd83560f805e0f79b7e.

Data set ID: 

136

EML revision ID: 

1

Data sources: 

Variables: 

year
  • Label:
  • Definition: The year in which data was collected.
  • Type: Physical quantity
  • Unit: Year (YYYY)
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
block
  • Label:
  • Definition: Samples are located in three blocks (Marheya, Nwanetsi, or Satara) of seven sample points in each watershed.
  • Type: Nominal
  • Missing values: None specified
fire
  • Label:
  • Definition: fire
  • Type: Code list
  • Codes:
    • 20 = unburned control
    • 1 = annually burned
    • 4 = burned once every four years
  • Missing values: None specified
trt
  • Label:
  • Definition: A numeric code indicating grazing treatment.
  • Type: Code list
  • Codes:
    • 2 = grazed
    • 1 = ungrazed
  • Missing values: None specified
plot
  • Label:
  • Definition: A numeric value indicating plot numbers 1-8 within each block. There are a total of seven plots per block.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
spnum
  • Label:
  • Definition: A unique numeric value assigned to each of the species in the data set.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
genus
  • Label: genus
  • Definition: The genus as published in USDA PLANTS database.
  • Type: Nominal
  • Missing values: None specified
species
  • Label: species
  • Definition: Specific epithet.
  • Type: Nominal
  • Missing values: None specified
cover
  • Label:
  • Definition: The percent cover of an observation (or vegetative unit) for a given species.
  • Type: Physical quantity
  • Unit: percentage
  • Maximum: 100
  • Minimum: 0
  • Precision: 0.01
  • Missing values: None specified

Categories
Dates

Date Range: 

Monday, January 2, 2006 to Tuesday, November 30, 2010

Publication Date: 

Thursday, April 18, 2019
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