Date
2015
Abstract
Climate models predict that water limited regions around the world will become drier and warmer in the near future, including southwestern North America. We developed a large-scale experimental system that allows testing of the ecosystem impacts of precipitation changes. Four treatments were applied to 1600 m2 plots (40 m × 40 m), each with three replicates in a piñon pine (Pinus edulis) and juniper (Juniper monosperma) ecosystem. These species have extensive root systems, requiring large-scale manipulation to effectively alter soil water availability. Treatments consisted of: 1) irrigation plots that receive supplemental water additions, 2) drought plots that receive 55% of ambient rainfall, 3) cover-control plots that receive ambient precipitation, but allow determination of treatment infrastructure artifacts, and 4) ambient control plots. Our drought structures effectively reduced soil water potential and volumetric water content compared to the ambient, cover-control, and water addition plots. Drought and cover control plots experienced an average increase in maximum soil and air temperature at ground level of 1-4° C during the growing season compared to ambient plots, and concurrent short-term diurnal increases in maximum air temperature were also observed directly above and below plastic structures. Our drought and irrigation treatments significantly influenced tree predawn water potential, sap-flow, and net photosynthesis, with drought treatment trees exhibiting significant decreases in physiological function compared to ambient and irrigated trees. Supplemental irrigation resulted in a significant increase in both plant water potential and xylem sap-flow compared to trees in the other treatments. This experimental design effectively allows manipulation of plant water stress at the ecosystem scale, permits a wide range of drought conditions, and provides prolonged drought conditions comparable to historical droughts in the past – drought events for which wide-spread mortality in both these species was observed.A micrometeorological station was used to document the climatic conditions at the study site. Monitoring the ambient environment in this way allowed us to more easily determine which tree growth responses were driven by changes in the native climate as opposed to those resulting from the rainfall manipulation treatments. Environmental factors such as temperature, relative humidity, and photosynthetically active radiation (PAR) have a huge impact on the physiological processes that are being explored in this project. The data collected by the station created a local climatic record which was needed to provide the context in which the treatment effects can be examined and sensor readings can be interpreted.
Handle
http://hdl.handle.net/1928/29951
Other Identifier
SEV273
Knowledge Network for Biocomplexity (KNB) Identifier
knb-lter-sev.273.386143
Document Type
Dataset
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/72e87ec43be131a9be28c2dbfddae29c
Temporal coverage
2007-01-01 - 2013-12-31
Spatial coverage
Location: The Cerro Montosa Pinyon-Juniper site has been the location of major Sevilleta LTER research since 1989. Meteorological trends, net primary productivity, rodent and ground-dwelling arthropod populations, mycorrhizal responses to fertilizer, pinyon-juniper fruit and nut production, and pinyon mortality are all being investigated at this site. Previous studies have included analyses of pinyon tree rings for regional climate reconstruction.Vegetation: The vegetation is New Mexico Pinyon-Juniper Woodland, dominated by Colorado pinyon (Pinus edulis) and one-seed juniper (Juniperus monosperma), and accompanied by gray oak (Quercus grisea). There is a diverse shrub component, including scrub live oak (Q. turbinella), mountain mahogany (Cercocarpus montanus), broom snakeweed (Gutierrezia sarothrae), sacahuista (Nolina microcarpa), red barberry (Mahonia haematocarpa), Apache plume (Fallugia paradoxa), tree cholla (Opuntia imbricata), skunkbush (Rhus trilobata), and banana yucca (Yucca baccata). Grass diversity is also high, and open spaces between trees are dominated by blue grama (Bouteloua gracilis), with hairy and sideoats grama (B. hirsuta and B. curtipendula) and black grama (B. eriopoda) also being significant. Other common grasses include purple threeawn (Aristida purpurea), wolftail (Lycurus phleoides), mountain and ring muhly (M. montanus and M. torreyi), and New Mexican porcupinegrass (Heterostipa neomexicana). Common forbs include small-flowered milkvetch (Astragalus nuttallianus), white sagebrush (Artemesia ludoviciana), Fendler’s arabis (Arabis fendleri), Fendler’s sandmat (Chamaesyce fendleri), New Mexico thistle (Cirsium neomexicanum), false pennyroyal (Hedeoma oblongifolia), bastard sage (Eriogonum wrightii), pingüe rubberweed (Hymenoxys richardsonii), large four o’clock (Mirabilis multiflora), Fendler's penstemon (Penstemon fendleri), and globemallows (Sphaeralcea hastulata and S. wrightii).
DOI
doi:10.6073/pasta/72e87ec43be131a9be28c2dbfddae29c
Permanent URL
http://dx.doi.org/10.6073/pasta/72e87ec43be131a9be28c2dbfddae29c
Recommended Citation
Pockman, William; McDowell, Nathan (2015): Ecosystem-Scale Rainfall Manipulation in a Piñon-Juniper Forest at the Sevilleta National Wildlife Refuge, New Mexico: Meteorological Data (2006-2013 ). Long Term Ecological Research Network. http://dx.doi.org/10.6073/pasta/72e87ec43be131a9be28c2dbfddae29c
Show full metadata
knb-lter-sev.273.386143-provenance.xml (4 kB)
Show provenance metadata
knb-lter-sev.273.386143-report.html (26 kB)
Show original LTER Network Data Portal ingest report
sev273_pjmet_20150508.csv (32616 kB)
Data in CSV format
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/72e87ec43be131a9be28c2dbfddae29c, and may be accessed at http://dx.doi.org/10.6073/pasta/72e87ec43be131a9be28c2dbfddae29c. 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.