An Integrated Methodology to Study Riparian Vegetation Dynamics: From Field Data to Impact Modeling. (19th August 2020) - Latella, M.
Abstract: Riparian environments are highly dynamic ecosystems that support biodiversity and numerous services and that are conditioned by anthropogenic activities and climate change. In this work, we propose an integrated methodology that combines different research approaches—field studies and numerical and analytical modeling—in order to calibrate an ecohydrological stochastic model for riparian vegetation. The model yields vegetation biomass statistics and requires hydrological, topographical, and biological data as input. The biological parameters, namely, the carrying capacity and the flood‐related decay rate, are the target of the calibration as they are related to intrinsic features of vegetation and site‐specific environmental conditions. The calibration is here performed for two bars located within the riparian zone of the Cinca River (Spain). According to our results, the flood‐related decay rate has a spatial dependence that reflects the zonation of different plant species over the study site. The carrying capacity depends on the depth of the phreatic surface, and it is adequately described by a right‐skewed curve. The calibrated model well reproduces the actual biogeography of the Cinca riparian zone. The overall percentage absolute difference between the real and the computed biomass amounts to 9.3% and 3.3% for the two bars. The model is further used to predict the future evolution of riparian vegetation in a climate‐change scenario. The results show that the change of hydrological regime forecast by future climate projections may induce dramatic reduction of vegetation biomass and strongly modify the Cinca riparian biogeography. Plain Language Summary: The riparian area is the transitional zone between a river and the land. This area hosts an elaborate ecosystem that supports high‐biodiversity and several natural and anthropic services. The physical processes governing the riparian area are so complex and interdependent that researchers have so far developed different scientific approaches to study them. In this paper, we combine some of these approaches (numeric, mathematical modeling, and field observations) in a unique methodology. The aim is to eventually provide a theoretical model for the riparian vegetation calibrated onto real data. The calibration regards the quantitative characterization of vegetation response to flood and drought. The calibrated model can consequently be used to study the spatial distribution of riparian vegetation in present and future climate scenarios. We show, for example, how the riparian vegetation of the Cinca River (Spain) will probably be affected by the variations in the hydrological regime induced by climate change. Key Points: We combined remote sensing, field data, and numerical and stochastic modeling to study a riparian area Topography and water level fluctuations condition the long‐term distribution of riparian vegetation Spatial clusters based on the probability of inundation detect areas of homogeneous vegetation