In 1989, line-intercept transects were installed to evaluate temporal and spatial dynamics across vegetation transition zones. Currently, a 400m transect is sampled at a grassland site (Deep Well) which is dominated by Bouteloua eriopoda (black grama) and, near the southern end of the transect, B. gracilis (blue grama). A second grassland site (Five Points), dominated by B. eriopoda and, to the south, Larrea tridentata (creosote), is also sampled. Both sites are sampled twice a year, in May/June and September/October, and measurements are taken at a one-centimeter resolution. The biannual sampling protocol detects potential responses in both cool and warm season plants as well as pre- and post-monsoon dynamics. Several transects have been discontinued and data archived within SEV200.
Knowledge Network for Biocomplexity (KNB) Identifier
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).
1989-01-01 - 2015-12-08
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: Five Points is the area which encompasses the Five Points Black Grama and Five Points Creosote Core study sites and falls along the transition between Chihuahuan Desert Scrub and Desert Grassland habitats. Both sites are subject to intensive research activity, including NPP measurement, phenology observation, pollinator diversity studies, and ground dwelling arthropod and rodent population assessments. There are drought rain-out shelters in both the Black Grama and Creosote sites, as well as the mixed-ecotone, with co-located ET Towers.Vegetation: The Five Points Creosote site is characterized as Chihuahuan Desert Scrub, dominated by a creosotebush overstory with broom snakeweed, purple pricklypear (O. macrocentra) and soapweed yucca as notable shrubs. The site is also characterized by numerous dense grass dominated patches, reflecting proximity to the Five Points Black Grama site and the relatively recent appearance of creosotebush. Dominant grasses are black grama, fluffgrass (Dasyochloa pulchellum), burrograss (Scleropogon brevifolia), bush muhly (M. porteri), and galleta (Pleuraphis jamesii). Notable forb species include field bahia (Bahia absinthifolia), baby aster (Chaetopappa ericoides), plains hiddenflower (Cryptantha crassisepala), Indian rushpea (Hoffmannseggia glauca), Fendlers bladderpod (Lesquerella fendleri), and globemallow (Sphaeralcea spp.). Five Points Black Grama habitat is ecotonal in nature, bordering Chihuahuan Desert Scrub at its southern extent and Plains-Mesa Grassland at its northern, more mesic boundary. There is also a significant presence of shrubs, particularly broom snakeweed (Gutierrezia sarothrae), along with less abundant fourwing saltbush (Atriplex canescens), Mormon tea (Ephedra torreyana), winterfat (Krascheninnikovia lanata), tree cholla (Opuntia imbricata), club cholla (O. clavata), desert pricklypear (O. phaeacantha), soapweed yucca (Yucca glauca), and what are presumed to be encroaching, yet sparsely distributed, creosotebush (Larrea tridentata). Characteristically, the dominant grass is black grama (Bouteloua eriopoda). Spike, sand, and mesa dropseed grasses (Sporobolus contractus, S. cryptandrus, S. flexuosus) and sand muhly (Muhlenbergia arenicola) could be considered co-dominant throughout, along with blue grama (B. gracilis) in a more mesic, shallow swale on the site. Notable forb species include trailing four o’clock (Allionia incarnata), horn loco milkvetch (Astragalus missouriensis), sawtooth spurge (Chamaesyce serrula), plains hiddenflower (Cryptantha crassisepala), blunt tansymustard (Descarania obtusa), wooly plaintain (Plantago patagonica), globemallow (Sphaeralcea wrightii), and mouse ear (Tidestromia lanuginosa)., siteid: 2Location: The southern edge of Mckenzie Flats, about 2.5 km west-northwest of the Five-Points intersection, siteid: 17
Collins, Scott (2015): Grassland Vegetation Line-Intercept Transects at the Sevilleta National Wildlife Refuge, New Mexico (1989 - present). Long Term Ecological Research Network. http://dx.doi.org/10.6073/pasta/df79b8cd91fb5d3442ee3990506ce89f