Fine-scale monitoring of climate change effects on the high-mountain
grassland ecosystem in the Romanian Carpathians

Project leader: Pavel Dan Turtureanu
Mentor: Mihai Pușcaș (BBU Romania), Collaborators: Philippe Choler (CNRS France, BBU Romania)
Postdoc project funded by: UEFISCDI – Executive Agency for Higher Education, Research, Development and Innovation Funding, Romania (2018-2020)

The main purpose of this work is to empirically examine the consequences of climate shifts on grassland ecosystems in the Romanian Carpathians. In order to achieve its ambition, the project will address three main objectives:

(i) Establishing new sites for long-term monitoring of high-mountain grassland response to climate change in the Romanian Carpathians. The Romanian Carpathians offers great opportunities to examine fascinating ecological settings. Therefore, for the success in our effort to understand and preserve the still largely extended and well preserved areas here, MEMOIRE will concentrate on recording original data from new representative grassland community types in these mountains.

(ii) Cross-validating remote sensing with ground-measured data of snow cover regime and ecosystem phenology in high-mountains of the Romanian Carpathians. This objective will seek to improve our ability to rely on digital satellite imagery to examine the effects of snow cover on ecosystem phenology and productivity (see Choler 2015). Thus, we expect to be able to enlarge the study of snow effects at a regional scale and time series not covered by information from the field. It has been determined that in the Northern Hemisphere, the snow-covered areas decreased since the borne optical sensors have been started to monitor the surface at the end of the 1970s. Then, in the Alps for example, altered snow regimes have been observed during recent decades by means of earlier melt dates (Hantel et al. 2012). In the high-mountain environments, snow cover regime plays a major role in determining ecosystem functions such as primary productivity (Choler 2015). During snow covered periods, subsurface soil temperatures exhibit very low variation, usually between -0.5 °C and 0.5°C, and this has been successfully determined by data loggers in all our monitoring projects. Although using data loggers is a relatively low-cost strategy to monitor the snow melting periods, it is beyond the bounds of possibility to fully cover the terrain with such devices.

Fig. 1 – (A) The sampling design with targeted high-elevated regions in the Romanian Carpathians – grid resolution ~ 100 km x 100 km; (B) Snowmelt patterns in the Făgăraș Mountains; (C) Snow cover indicated by constant temperatures in soil, recorded with a data logger in the Carpathians (winter 2014-2015).

(iii) Modelling the response of the high-mountain grassland ecosystems to climate change in the Romanian Carpathians. MEMOIR will use data collected from in situ and driven from satellite imagery products to quantify the impact of climate change on important ecosystem properties, such as species richness and above- and belowground biomass nutrient C:N:P ratios, and functions, such as primary productivity. Importantly, the study will benefit from the advantages provided by the use of temperature data loggers to calculate of biologically meaningful local parameters (e.g. temperature during summer, winter frost, snow duration, snowmelt date). We will make use a combined approach including: (i) interannual variations of ecosystem responses (through remote sensing) and (ii) along topographical fine scale spatial gradients for one or two years of investigation. In high-mountain settings, topography is known to regulate the microclimate, particularly the snowmelt regime.