Field Experiments & Instrumentation / Workshops                    --- Making Things Happen ---     


Las Majadas del Tietar (Spain)


Location

Dehesa - open holm oak woodland with traditional grazing management

Latitude 39.94
Longitude -5.77
Elevation 260 m a.s.l.

Overview

  • Since 2014 until now
  • CEAM-Eddy since 2003)
  • MaNiP - field manipulation experiment
  • Tree growth
  • Meteorology
  • Soil conditions
  • Chamber measurements
  • Lysimeter

Project

Collaboration

Dr. Arnaud Carrara, Research Scientist; Ramón Lopez, Industrial Engineer/ Technician

CEAM- MAJADAS (in Spanish)

Description & History

The site is located in an open holm oak woodland (dehesa) in Majadas del Tietar, Caceres, Spain (39°56′ N; 5°46′ W, 260 m a.s.l.).

The soil is classified as Cambisol (Dystric) [IUSS Working Group WRB, 2006] and originated from Pliocene‐Miocene alluvial deposits. The soil profile is about 90 cm deep with a clay horizon upper limit at a depth between 30 and 60 cm; in contrast, the texture in the upper horizons is sandy (9.3% clay, 10.7% silt, 80.0% sand). The pH (H2O) is about 5.6 in the first 15 cm. Soil organic matter and associated extractable C fractions decrease sharply in the first 15 cm of soil.

The climate is continental Mediterranean with temperate winters. Mean annual temperature is 16.7°C and mean annual precipitation is 528 mm, with less than 6% of precipitation occurring during summer. Occasional rainfalls occur during five to ten summer days per year with usually less than 20 mm per day.

The open tree stratum (24.8 trees ha−1) is composed of evergreen holm oak (Quercus ilex ssp ballota Lam.) with occasional presence of Q. suber L. or Q. faginea Lam. (<5%). Tree canopy fraction is 19.8% on average. The herbaceous stratum is mainly composed of annual species (Vulpia bromoides (L.) SF Grey; V. geniculata (L.) Link; Trifolium subterraneum L., Ornithopus compressus L.), that senesce by the end of May.

The site is subjected to traditional grazing management (see Lopez‐Sangil et al. [2011]).

In March 2014 two identical Eddy covariance flux measurement towers were erectet. A third smaller tower, a so called subcanopy eddy covariance tower, was built in June 2014.

June 20, 2014, A new subcanopy eddy covariance system has been installed in Las Majadas!!

The vegetation period in 2014 serves as status quo before in 2015 the P and N manipulation experiment starts.

Mid of October 2015: travel to Majadas and build up of 6 additional towers (2 subcanopy eddy towers, 3 radiation towers and a mobile tower at a dryer site) and the various sensors belonging to them

Variables & Instruments

Fluxes

  • Eddy
  • Subcanopy Eddy
  • Profile at 7 heights - CO2

Meteorology

  • Wind velocity and wind direction - USA-1, Metek
  • Air pressure - pressure transmitter 61302V, Young
  • Air temperature and humidity - temperature-humidity-sensor KPK1_5-ME, Mela
  • Precipitation - tipping bucket rain gauge, Thies
  • Solar radiation - net radiometer CNR4, Kipp & Zonen
  • Terrestrial radiation - net radiometer CNR4, Kipp & Zonen
  • Photosynthetically active radiation - PAR sensor PQS1, Kipp & Zonen
  • PRI / NDVI - PRI Sensors

Soil conditions

  • Soil temperature - soil temperature sensors PT100, home-made
  • Soil moisture - soil moisture probes ML-2x, Delta-T
  • Soil moisture (profile/ grid)- Soil Moisture Probe EnviroSCAN , Sentek Easy AG
  • Soil temperature profile (5, 10, 20, 30, 50 & 100 cm) - Soil Temperature Profile ProbeTh3, UMS

Data acquisition

  • Meteorological data - datalogger CR3000, Campbell Scientific
  • CO2 -Profile - datalogger CR3000, Campbell Scientific

Publication

Casals, P., L. Lopez‐Sangil, A. Carrara, C. Gimeno, and S. Nogués (2011). Autotrophic and heterotrophic contributions to short‐term soil CO2 efflux following simulated summer precipitation pulses in a Mediterranean dehesa. Global Biogeochem. Cycles, 25, GB3012, doi:10.1029/2010GB003973.

Lopez‐Sangil, L., J. Rousk, H. Wallander, and P. Casals (2011). Microbial growth rate measurements reveal that land‐use abandonment promotes a fungal dominance of SOM decomposition in grazed Mediterranean ecosystems. Biol. Fertil. Soils, 47, 129–138, doi:10.1007/s00374-010-0510-8.