Modeling Soil Water Dynamics and Pasture Growth in the Montado Ecosystem Using MOHID Land

Abstract

The southern Iberian Peninsula is characterized by evergreen oak woodlands (locally known as montado), which constitute an important savanna-type agro-silvo-pastoral ecosystem. This ecosystem is facing a progressive decline for several reasons, with the foremost being overgrazing. Better management tools are necessary to accurately quantify the systems' carrying capacity and the sustainable stocking rates that prevent land degradation. The purpose of this study was to determine whether the MOHID-Land model could adequately simulate soil water dynamics and pasture growth in the montado ecosystem. The study area was located in the Alentejo region of southern Portugal. The model successfully simulated soil water contents and aboveground biomass during the 2010-2011 and 2011-2012 growing seasons, producing acceptable errors of the estimates (0.015 ≤ RMSE ≤ 0.026 cm 3 cm −3 ; 279 ≤ RMSE ≤ 1286.5 kg ha −1), and relatively high modeling efficiencies (0.481 ≤ EF ≤ 0.882). The model was further used to simulate the same variables for a longer period (1979/2009 seasons), to account for the effect of climate variability on model estimates. Water balance and dry biomass estimates were found to be significantly different between rainfed and irrigated pastures, as well as between the ten driest and ten wettest seasons, with the model responding well to climate variability. The results showed the potential of using the MOHID-Land model for improving pasture management in the montado ecosystem.

An Integrated Modelling Approach to Study Future Water Demand Vulnerability in the Montargil Reservoir Basin, Portugal

“…Higher temperatures, which result in an increase of potential evapotranspiration, also concur with this situation (Figure 12). The baseline monthly actual evapotranspiration values are in accordance with the detailed work developed by Simionesei et al [48] to pasture and Ramos et al [49] to maize grown in the Sorraia basin. Vegetation growth in the region may be compromised due to higher water stress as a result of higher evapotranspiration demand and limitations in water available for irrigation.…”

The Effects on Greenhouse Gas Emissions of Ecological Intensification of Meat Production with Rainfed Sown Biodiverse Pastures

“…This approach also has limitations, such as, for example, the influence of tree cover. This effect is particularly relevant in these "Montado" agri-forestry regions due to high tree cover density (e.g., 170 trees/ha of Quercus suber [57]), 2 as trees also influence aboveground biomass productivity [58]. Here, we used the process-based model RothC calibrated for SBP (root to shoot ratio, livestock intake fraction, livestock excretion during grazing, and easily decomposable plant material (DPM)/resistant plant material (RPM) ratio), which can consider some site-specific conditions if available-such as regionalized aboveground productivity and stocking rate.…”

Modelação da rega deficitária em vinha com o MOHID-Land

“…Para o período de validação (2018), os erros das estimativas mantiveram-se na mesma ordem de grandeza dos obtidos durante a calibração do modelo (RMSE = 0.029 m 3 m -3 ; NRMSE = 0.012), o modelo subestimou os dados observados em 3.25%, enquanto que a EF aumentou consideravelmente (EF = 0.706). Considerou-se, assim, que o modelo MOHID-Land conseguiu reproduzir com sucesso os valores do teor de água no solo observados na rega da vinha durante dois anos, apresentando indicadores estatísticos semelhantes aos obtidos noutras aplicações do mesmo género [4,20,21].…”