Date

2010

Abstract

Our objective was to evaluate the effects of kangaroo rat mounds on species diversity and composition at a semiarid-arid grassland ecotone. We expected that source populations of plants occurring on kangaroo rat mounds have important influences on the species composition of vegetation at the landscape scale, and that these influences differ by grassland type. Our study was conducted at the Sevilleta LTER in New Mexico, where a grassland type dominated by Bouteloua gracilis, a shortgrass steppe species, and a grassland type dominated by B. eriopoda, a desert grassland species, meet to form patches across the landscape.Four 0.4 ha plots were sampled for species diversity and composition in a regular 7m x 7m grid in each grassland type. Kangaroo rat mounds were also mapped and sampled for vegetation measures in four areas of 1.6 ha in each type. The landscape scale abundance of many subordinate species was increased significantly by populations occurring on kangaroo rat mounds in both grassland types. However, the area affected by the burrowing activity of kangaroo rats was twice as large in the B. eriopoda dominated grassland type. Furthermore, dominant plants on mounds in the B. eriopoda type were also abundant in off-mound areas whereas dominant plants on mounds in the B. gracilis type were not as abundant off-mound. These results indicate that the presence of mounds in the B. gracilis dominated type is creating islands of plant communities that are distinct from the rest of the grassland. Therefore, the occurrence of certain plant species in this grassland type may be intimately associated with the disturbance regime at this ecotone. This study demonstrates that effects of small burrowing animals may facilitate the coexistence of species at this ecotone.

Handle

http://hdl.handle.net/1928/30034.1

Other Identifier

SEV169

Knowledge Network for Biocomplexity (KNB) Identifier

knb-lter-sev.169.1

Document Type

Dataset

Comments

This dataset was originally published on the Long Term Ecological Research (LTER) Network Data Portal, https://portal.lternet.edu, and potentially via other repositories or portals as described. The Digital Object Identifier (DOI) of the source data package is doi:10.6073/pasta/98d1cf86bfa105cb649c2e5658c0210a, and may be accessed at http://dx.doi.org/10.6073/pasta/98d1cf86bfa105cb649c2e5658c0210a. Metadata and files included in this record mirror as closely as possible the source data and documentation, with the provenance metadata and quality report generated by the LTER portal reproduced here as '*-provenance.xml' and *-report.html' files, respectively.

Rights

Data Policies: This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. Datasets must be cited as in the example provided. A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager. By downloading any data you implicitly acknowledge the LTER Data Policy (http://www.lternet.edu/data/netpolicy.html).

Source

http://dx.doi.org/10.6073/pasta/98d1cf86bfa105cb649c2e5658c0210a

Temporal coverage

1999-08-01

Spatial coverage

Location: Deep Well is located on McKenzie Flats and is site of the longest running SEV LTER met station, number 40, which has been active since 1988. In addition to studies of meteorological variables, core line-intercept vegetation transects and line-intercept transects from the 1995 and 2001 Deep Well fires are sampled here. The mini-rhizotron study, blue and black grama compositional comparison, blue and black grama patch dynamics investigation, and kangaroo rat population assessement are all ongoing here. Deep Well Blue/Black Grama Mixed is also the location of the warming and monsoon experiments, as well as portions of the line-intercept and vegetation removal studies. On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge. By August 5, 2009, the fire had reached the area of Deep Well Blue/Black Grama Mixed. While portions of this site were burned, the entirety was not. See individual projects for further information on the effects of the fire.Vegetation: The vegetation of Deep Well Blue/Black Grama Mixed is Chihuahuan Desert Grassland, dominated by black grama (Bouteloua eriopoda) and blue grama (B. gracilis). Other grasses found at the site include dropseeds (Sporobolus spp.) and threeawns (Aristida spp.). Shrubs are uncommon but those that occur include Yucca glauca, Ephedra torreyi, and four-wing saltbush (Atriplex canescens). Herbaceous plants include Plantago purshii, Hymenopappus filifolius, and globe mallows (Sphaeralcea spp.). , Location: McKenzie Flats is located within the northeastern section of the Sevilleta NWR, encompassing an area from Black Butte south to Palo Duro Canyon and east to the Los Pinos.Landform: McKenzie Flats is a broad, nearly flat grassland plain between the Los Pinos Mountains and the breaks on the east side of the Rio Grande., Geology: Deep (20,000 ft) alluvial and aeolian deposits., Soils: Turney Series: fine-loamy, mixed, thermic Typic Calciorthids. Berino Series: fine-loamy, mixed, thermic Typic Haplargids., Hydrology: Surface water only during rain events, no arroyos. Run-on plain for Los Pinos Mountains., Vegetation: The terrain is generally a mixed-species desert grassland, dominated by black grama (Bouteloua eriopoda), blue grama (B. gracilis), sand muhly (Muhlenbergia arenicola), various drop seeds and sacatons (Sporobolus spp.), purple three-awn (Aristida purpurea), and burrow grass (Scleropogon brevifolia). Shrubs are common in the area around Five Points, including creosote bush (Larrea tridentata) and snakeweed (Gutierrezia sarothrae)., Climate: Long-term mean annual precipitation is 243 mm, about 60% of which occurs during the summer. Long-term mean monthly temperatures for January and July are 1.5 degrees C and 25.1 degrees C, respectively., History: McKenzie Flats encompasses an area of approximately 50 square miles and was one of the primary livestock grazing areas within what is now the Sevilleta NWR. Cattle have been excluded from the site since 1974-76. The ranch headquarters buildings and corrals were located at the junction of Legs C and D of the coyote survey, siteid: 25

DOI

doi:10.6073/pasta/98d1cf86bfa105cb649c2e5658c0210a

Permanent URL

http://dx.doi.org/10.6073/pasta/98d1cf86bfa105cb649c2e5658c0210a

knb-lter-sev.169.1-metadata.html (177 kB)
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knb-lter-sev.169.1-provenance.xml (5 kB)
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knb-lter-sev.169.1-report.html (25 kB)
Show original LTER Network Data Portal ingest report

sev169_krat_07312012.txt (50 kB)
Data in TXT format

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