Habitat Changes along Ipoly River Valley (Hungary) in Extreme Wet and Dry Years

Ildikó T.-Járdi,Eszter S.-Falusi,Zalán Zachar,Károly Penksza,Réka Láposi,Gergő Péter Kovács,Dénes Saláta

doi:10.3390/w14050787

Abstract

The Ipoly Valley is a natural habitat along the Ipoly River, only slightly affected by water management; therefore, this is an especially sensitive area and reflects well the vegetation changes in the driest (2020) and wettest (2010) years. The study’s aim is to identify natural changes within habitats and the evaluation of habitat types’ boundaries. For the study, a hand-held GPS device was applied on-site. The habitat identification is based on the General National Habitat Classification System (Á-NÉR). In addition to on-site data, Sentinel-2A satellite data were used to compare different extreme years 2020 and 2021—changes in different habitat patches using different vegetation indices. A change in precipitation causes shifts in the vegetation, this is shown on a map. As we predicted, decreasing the precipitation results in a decrease of the area of wet habitat patches. The satellite image shows a more accurate picture of the real location of the associations, which is important for long-term research. In addition, we can get accurate data on the situation of areas (roads and paths) affected by anthropogenic factors.

Highlights

An increase in climate extremes has been observed in Europe due to global climate change [2], more frequent droughts and floods were measured in the Carpathian Basin [3,4]
Our questions were the following: Could we identify the effects of precipitation on vegetation based on habitat maps from the extreme years 2010 and 2020? Could we identify habitat transformation and if a change is detected, what kind of vegetation and habitat types are affected and in what way? In addition, we would like to confirm the finding of what differences or similarities can be found when using a non-traditional method when comparing 2 years between different precipitation conditions
We observed in wet patches of the habitat that the species change as well; some indicators of the dry habitats are Achillea collina, Plantago lanceolata, Dactylis glomerata, Agropyron repens, and Festuca arundinacea

Summary

Introduction

It can be seen in a previous study that the Ipoly region is sensitive to environmental changes, in which it has been shown that certain wetlands change significantly [1]. The vegetation and habitats of flood-basin areas along the rivers, which are known to react the most sensitively to environmental changes (in this case to the change in water table) [1,8,13,14], as the Ipoly Valley. It has a linear nature, Ipoly Valley harbors especially mosaic-like vegetation, mainly because it is a nonregulated, natural watercourse [1]; Ipoly River is one of the last rivers least affected by water management in Hungary. Based on the NDVI and GNDVI index data, the water space shows the lowest value due to the low biological activity. Comparing the satellite images from 2020 (Figure 4a) and 2021 (Figure 4e), it can be seen that the eu- and mesotrophic reed and Typha beds (B1a) habitat in a large area in the middle of the map show a higher

Methods

Results

Discussion

Conclusion