The soil moisture regime and groundwater recharge in aged forests in the Sand Ridge region of Hungary after a decline in the groundwater level: an experimental case study

Abstract

The decline in groundwater levels is a cause of concern in many regions of the world, including the Sand Ridge of Hungary. The causes of the regional depletion range from rising air temperatures, changes in precipitation, domestic and agricultural groundwater use and past amelioration and recent afforestation, including the effects of drilling for crude oil exploration. The relations between the decline, the soil water regime and groundwater recharge under existing aged forests remained unclear thus far. Based on our monitoring of groundwater and soil moisture we aim to clarify this interplay in a new experimental site on the hilltop of the Sand Ridge. We compared three land-uses: a 41-year-old black locust (Robinia Pseudoacacia) offshoot forest, an 83-year-old first generation black pine (Pinus nigra) forest, and a grassland control site. The observed differences in the soil moisture profiles and dynamics were connected to the use of water by the given type of vegetation. We indicated a connection between the disruption of the groundwater recharge and the loss of contact of the rooting system of the forests with the deepening of the unconfined aquifer. Even if the aged forests could locally contribute to the decline, we conclude that the decline at the hilltop site that may be more strongly driven by other regional factors.

Groundwater Recharge from Below under Changing Hydro-Meteorological Conditions in a Forested and Grassland Site of the Great Hungarian Plain

“…Hence, it is of utmost importance to investigate the spatiotemporal dynamics of evapotranspiration and recharge rates in response to alterations in land use and climate conditions [2]. These topics have received continual attention in the literature around the globe [3][4][5][6][7][8].…”

Evaluation of the Compound Effects of the 2022 Drought and Heatwave on Selected Forest Monitoring Sites in Hungary in Relation to Its Multi-Year Drought Legacy

“…The drought was less typical and had no clearly detectable negative effects at the Scots pine (M15) and sessile oak (M16) forest stands in 2022. It had the greatest negative effect on the black locust forest stand (M19) in the Sand Ridge region in the Great Plain, where the lack of water was already typical in the past and is even increasing nowadays (Szabó et al, 2022) [66].…”

Soil Moisture Conservation through Crop Diversification and Related Ecosystem Services in a Blown-Sand Area with High Drought Hazard

“…Inorganic carbonates are found in medium amounts (3.5–4.5%). Soil fertility and the choice of agricultural crops are first of all limited by the low soil moisture content, as well as its extreme seasonal distribution and the low water retention capacity of the topsoil [ 35 , 36 , 37 ]. Frequent desiccation exposes the soil to sandstorms, which carry away large amounts of low-density humus particles.…”