Drought Frequency Research Articles

Capacity development training workshop on crop simulation modelling and effects of climate risks on agricultural production systems in Southeast Asia

Southeast Asia (SEA) has experienced frequent floods and droughts, posing severe challenges for farmers, agricultural scientists and extension officers. Consequently, crop modelling has become imperative in developing agricultural production systems and making informed decisions at the field level. The Decision Support System for Agrotechnology Transfer (DSSAT) can be effectively utilised at both farm and regional levels to assess the influence of climate change on production across different spatial scales. Moreover, it supports planning adaptation strategies tailored to the needs of farmers. The one-week hands-on training workshop aims to enhance technical and scientific proficiency in crop simulation modelling and evaluate the effects of climate risks on agricultural production systems in Southeast Asian countries such as Cambodia, Lao PDR, Thailand and Vietnam. A total of 62 participants from the selected countries, including Singapore and Ethiopia, were joined in the training. Among them were 48 male and 24 female individuals, comprising researchers, students, scientists, academicians and extension officers. The participants predominantly acquired knowledge of crop simulation modelling techniques by utilising existing case examples and lecture materials from the DSSAT foundation. Furthermore, the training workshops establish research networks and collaborations among the participant countries, facilitating the exchange of scientific knowledge related to innovative farm management practices and fostering interactions between local agricultural communities and scientists.

Assessment of drought changes, trends, frequency and duration in the Gulf of Guinea region (west africa)

Assessment of drought changes, trends, frequency and duration in the Gulf of Guinea region (west africa)

The impacts of climate change on meteorological drought in the Central Highlands region of Vietnam

ABSTRACT This study aimed to analyse the characteristics of drought under the impacts of climate change in the Central Highlands of Vietnam. The standardized precipitation indices at 3-, 6-, 9- and 12-month time scales were calculated based on the average monthly precipitation at 11 meteorological stations between 1985–2014. The drought characteristics were analysed based on the modified Mann-Kendall test, Theil-Sen methods and the theory of runs. Analysing the impact of climate change on drought events, four CMIP6 GCM models, namely, CNRM-CM6-1-HR, MRI-ESM2-0, BCC-CSM2-MR and MIROC6, under the SSP2-4.5 and SSP5-8.5 scenarios were used to obtain the average monthly precipitation for the period 2031-2060 to compute the SPI3, SPI6, SPI9 and SPI12. The results indicate that the drought frequency under the SSP5-8.5 scenario ranges from moderate to severe. The BCC-CSM2-MR, CNRM-CM6-1-HR and MIROC6 models showed an increase in drought frequency from 2 to 4% for SPI3 and SPI6 and from 4 to 6% for SPI9 and SPI12. Under the SSP2-4.5 scenario, the frequency of severe droughts also increases by 2-4% compared with that in the 1985-2014 baseline periods for SPI6, SPI9 and SPI12. Consequently, moderate to severe drought episodes are predicted to occur more frequently in the research area.

The Impact of Changing Climate on an Endangered Epiphytic Orchid (Pleione formosana) in a Montane Cloud Forest and the Conservation Challenge Ahead.

Pleione formosana Hayata is an endemic orchid that was once widely distributed across the mid-elevations of Taiwan. However, populations of this orchid have steadily shrunk due to orchid poaching in most of its habitats. By correlating data from micrometeorological stations that we installed in the cloud forest canopy at the study site, Yuanyang Lake (YYL) from 2017, we discovered the critical role of spring rainfall in triggering flowering and summer rainfall in promoting the growth of new bulbs. We found that rising temperatures and frequent drought events threaten orchid growth, potentially leading to pathogen infections. We climbed old-growth yellow cypresses to collect seed capsules of P. formosana for in vitro germination at YYL beginning in the autumn of 2018. Orchid plantlets were reintroduced to the study site in mid-August of 2022. However, the seedlings failed to survive the summer of 2023. This study is the first persistent monitoring of this rare orchid in the forest canopy of this old-growth cloud forest. Based on the result, we propose conservation strategies and directions for protecting this orchid on a regional scale. Our study highlights the mounting challenge to conservation efforts posed by global climate change.

Impact of projected climate variability on agricultural water demand of key crops in drought-prone central India region

ABSTRACT Water scarcity predominantly affects agriculture production. It is mandatory to save future water to prevent its shortage due to variations in climate. Variation in climate is a significant factor responsible for frequent droughts over the Bundelkhand region in central India. It is necessary to obtain early warning studies in this region to manage and arrange future agricultural water. Out of best Regional Climate Models (RCMs) under the Coordinated Regional Downscaling Experiment (CORDEX) and their driving Coupled Model Intercomparison Project Phase 5 (CMIP5), General Circulation Models (GCMs) for India, the most effective model has been found based on the observed multiscale data for the region. The daily projected data (2021–2100) of best GCM, Earth System Model, ESM-2M have been used to evaluate the future water requirements for major rabi and hot weather crops grown in the region. The climate change effect is seen in the majority, especially in the upper Bundelkhand part. Most of the crops will need more water than the present condition, especially from 2071 to 2100. The findings will also help researchers and policymakers to utilize the future projected data to propose suitable water management strategies for agriculture.

Exploring climate shifts in the Ganga-Brahmaputra basin based on rainfall and temperature variability.

Climate change has a significant impact on the Ganga-Brahmaputra (GB) basin, the major food belt of India, which frequently experiences flooding and varied incidences of drought. The current study examines the changing trend of rainfall and temperature in the GB basin over a period of 30years to identify areas at risk with an emphasis on the Paris Agreement's mandate to keep increasing temperatures below 2°C. The maximum temperature anomaly in the middle Ganga plains recorded an increase of more than 1.5°Cyear-1 in 1999, 2005, and 2009. Some extreme events were observed in the Brahmaputra basin during 1999, 2009, and 2010, where a prominent temperature increase of 1.5°Cyear-1 was observed. The minimum temperature revealed an increasing trend for the G-B basin with an anomalous increase of 0.04 to 0.06°Cyear-1. The rainfall variability across the Ganga basin shows a rising tendency over the lower Ganga region while the Brahmaputra basin showed a downward trend. To identify the statistical relation between the Global climatic oscillations and regional climate, Standardized Precipitation Index (SPI) and Niño 3.4 were used. The wet and dry period estimation shows a rise in flood conditions in the Ganga basin whereas, in the Brahmaputra basin, an increase in drought frequency was observed. The correlation based on Niño 3.4 and SPI3 presents a negative relation for the monsoon season in the G-B basin revealing a situation of drought occurrence (SPI3 below 0) with increased Nino 3.4 values (El Niño above + 0.4C).

The Response of NDVI to Drought at Different Temporal Scales in the Yellow River Basin from 2003 to 2020

Ecological protection in the Yellow River Basin (YRB) is a major strategy for China’s sustainable development. Amid global warming, droughts have occurred more frequently, severely affecting vegetation growth. Based on the Standardized Precipitation Evapotranspiration Index (SPEI) and Normalized Difference Vegetation Index (NDVI) at different time scales from 2003 to 2020, this study employed the linear trend method and the Spearman correlation coefficient method to calculate the trends and correlation coefficients of NDVI and SPEI at different scales at the pixel scale and explored the spatial distribution pattern of the sensitivity of vegetation growth in the YRB to drought. The results show that: (1) NDVI and SPEI are positively correlated in 77% of the area, negatively correlated in 9%, and are positively correlated in the arid and semi-arid areas, while negatively correlated in the humid and subhumid areas. The significant negative correlation between NDVI and drought at high altitudes may be due to the fact that Gramineae vegetation is more sensitive to drought, with heat being more affected than water. (2) Urbanization has a relatively obvious impact on the distribution of drought. Extreme drought mainly occurs in the middle and upper reaches of the Wei River; severe drought mainly occurs in the central area of the Guanzhong Plain centered on Xi’an; the central area of the Loess Plateau; and the surrounding areas of the Zhengzhou-centered Central Plains City Group. (3) The NDVI showed an upward trend from 2003 to 2020, indicating an increase in vegetation density or an expansion of vegetation coverage. From the temporal trend, SPEI decreased at a rate of −0.17/decade, indicating that the entire watershed has a drought trend on an annual scale. (4) Spring NDVI is more sensitive to the water supply provided by SPEI-1, while the positive correlation between SPEI and NDVI begins to rise in June and reaches its peak in July, then starts to decline in August. In autumn and winter, NDVI is more sensitive to 3–6-month accumulated drought. (5) From the dynamic transmission laws of different levels of positive correlation, the positive impact of the 3-month accumulated drought on NDVI is most significant, and the influence of SPEI-1 on the negative correlation between SPEI and NDVI is most significant. This paper aims to clarify the sensitivity of vegetation to different time-scale droughts, provide a basis for alleviating drought in the YRB, and promote sustainable development of ecological environmental protection. The research findings enable us to gain a profound insight into the responsiveness of vegetation growth to drought in the context of global warming and offer a valuable theoretical foundation for devising pertinent measures to alleviate stress on vegetation growth in regions prone to frequent droughts.

Analysis of the Impact of Climate Change on the Safety of Water Conservancy Facilities

This study analyzes the impact of climate change on the safety of water conservancy facilities, focusing on dams, levees, reservoirs, and water supply systems. Climate change induces increased flood risks, more frequent droughts, sea level rise, and extreme weather events, which challenge the integrity and functionality of these infrastructures. The research highlights the need for resilient designs, advanced technologies, and improved management practices to mitigate these impacts. By adopting flexible design standards, utilizing innovative materials, and enhancing emergency response plans, water conservancy facilities can better withstand climate-related stresses, ensuring water security and sustainability.

Intensity, frequency and coverage of hydro-meteorological droughts and agriculture in the semi-arid basins of Maharashtra (India)

Intensity, frequency and coverage of hydro-meteorological droughts and agriculture in the semi-arid basins of Maharashtra (India)

The effects of climate change and regional water supply capacity on integrated drought risk

Due to climate change, the frequency and duration of meteorological drought have increased. In addition, local water supply capacity has not met water demand in many regions, which will eventually lead to serious water shortages. To mitigate the effects of drought on sustainable water use, it is necessary to understand how climate change affects regional water supply capacity and drought risk. To this end, this study evaluated the drought response capacity of regional water supply systems and assessed the comprehensive drought risk in terms of drought hazard, vulnerability, and response capacity. To avoid subjectivity in risk analysis, structural equation modeling was used to select primary indicators and probability and statistical methods were used to assign weights to the indicators. The changes in drought risk in different climate change scenarios were assessed using sensitivity analyses. The overall results indicate that the future drought risks in Gyeonggi, Gyeongsang, Chungcheong, Jeolla, and Gangwon are 18, 12, 13, 9, and 10% higher, respectively, than the current risk level. The sensitivity analyses showed that Jinju in Gyeongsang province, which has a high drought response capacity, had the largest decreasing rate in drought risk. The quantified changes in drought risk under future climate change scenarios will be useful for identifying areas with a high drought risk and making decisions about drought mitigation under climate change.

Spruce suffers most from drought at low elevations in the Carpathians, though shows high resilience

More frequent and severe droughts have affected forest ecosystems throughout Europe in recent decades. In Central Europe, large-scale dieback of Norway spruce has, for example, been observed, whereas Norway spruce decline was so far less widespread in Eastern Europe. To assess the potential future impacts of drought on Norway spruce in the southeastern part of its natural distribution, studies on drought resilience are urgently needed. Here, we use a tree-ring network consisting of more than 3000 trees from 158 managed Norway spruce stands of different ages distributed along elevational gradients in the Eastern Carpathians to assess growth responses to drought. Specifically, we analyzed differences in resilience components (e.g., resistance, recovery, resilience, recovery period) with elevation and tree age, and used the ‘line of full resilience’ concept to comprehensively assess drought resilience. Our results show that Norway spruce at low elevations (<800 m) is characterized by the lowest resistance to drought, though has a high recovery, while at high elevations (>1400 m), a higher resistance is associated with a low recovery. In general, older trees were found to need more time to recover. Resilience decreases with a higher water deficit, suggesting that Norway spruce is at risk in the Carpathians with ongoing climate change, urging the need for adaptative forest management.

EVALUATING REMOTE SENSING-BASED DROUGHT INDICES: STRENGTHS, LIMITATIONS, AND APPLICABILITY ACROSS SUB-SAHARAN AFRICA'S AGRO-ECOLOGICAL ZONES: A REVIEW

This study reviews the application and effectiveness of various remote sensing (RS) indices for drought monitoring in Sub-Saharan Africa (SSA). Given the region’s diverse climatic zones and frequent drought occurrences, accurate and timely assessment tools are crucial. The study examines indices from different spectral regions, including optical, thermal infrared, and microwave bands, focusing on their spatial and temporal resolutions, data availability, strengths, and limitations. Optical indices such as the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Water Index (NDWI) are effective in semi-arid and sub-humid zones where vegetation density varies. Thermal infrared indices, including the Temperature Condition Index (TCI), the Vegetation Health Index (VHI), and the Temperature Vegetation Dryness Index (TVDI), provide insights into thermal anomalies and vegetation health, with TCI particularly suited for semi-arid zones and TVDI useful in both semi-arid and sub-humid zones. Microwave indices, such as the Normalized Backscatter Moisture Index (NBMI), Vegetation Optical Depth (VOD), and the Microwave Polarization Difference Index (MPDI), excel in capturing soil moisture and vegetation water content, proving useful in humid forest and semi-arid zones. The integration of these indices with other meteorological and hydrological data enhances drought monitoring and management strategies. Recommendations are made for the optimal use of these indices across different SSA agroecological zones.

Climatic limitations of nearly endangered Juniperus rigida populations at their range edges in semiarid China

The treat of climate warming is expected to increase the frequency and severity of droughts and significantly affect tree growth and distribution ranges, particularly in regions without monsoons. The distribution limits of tree species are highly susceptible to climate change. A deeper understanding of how tree species respond to climate across their distribution ranges is crucial for accurately predicting forest dynamics in the face of climate warming. Using tree ring width data from 586 trees at 19 sites spanning the northernmost and southernmost limits of Juniperus rigida (near-threatened, IUCN: NT), we assessed the growth responses of J. rigida to climate at different distribution range limits. We observed significant differences in tree-growth variability between the southern and northern populations of J. rigida, characterized by an increasing growth trend at the southern range limit, but a decreasing trend at the northern limit since 1996. Moreover, tree growth at their northern limit was hindered by high temperatures and SPEI during summer months, whereas it was constrained by low temperatures in March and precipitation in June at the southern limit. Particularly noteworthy is the increased sensitivity of growth to SPEI and precipitation in recent decades (1996–2018) compared to previous decades (1961–1995), particularly at their northern distribution edge. We therefore conclude that the growth of J. rigida trees at the southern limit could benefit from climate warming, while increasing warming and drought could limit tree growth or even cause tree mortality at the northern range limits. These findings may serve as an early warning for the growth and survival of J. rigida trees in open forests at their northern distribution edges in the face of future climate warming.

Impact of deficit irrigation and planting density on grain yield and water productivity of maize grown under temperate continental climatic conditions

Variable frequent drought periods in Vojvodina region (the southeastern part of the Pannonian Plain, Serbia), severely limit maize (Zea mays L.) production under rainfed conditions. A four-year field experiment was conducted to investigate the effects of sprinkler deficit irrigation and plant density on yield and water use efficiency of maize grown on silty clay loam soil under temperate continental climate. The experiment included fully irrigated crop (I1), three deficit irrigation treatments (I2, I3 and I4 corresponding to 80, 50 and 40 % of crop evapontranspiration, respectively) and non-irrigated treatment (I0), and three plant densities (LPD: 54,900 plants ha–1; MPD: 64,900 plants ha–1; HPD: 75,200 plants ha–1) in four replicates. The results showed that grain yield, CWP (crop water productivity) and IWP (irrigation water productivity) varied significantly with irrigation amounts, plant densities and seasons. The irrigation rates and plant density interact significantly. MPD and HPD differed significantly from LPD in almost all seasons. With increasing irrigation and plant density, yield and CWP showed an increasing trend. The relative values of IWP increased with the rise of plant density and decreased with the amount of irrigation. The highest four-year average yield (15.03 t ha–1) was obtained in the I1-HPD treatment, while the lowest (9.30 t ha–1) was obtained in the I0-HPD treatment. The highest average values of CWP and IWP were recorded at I3-HPD or/and I2-HPD. The lowest CWP and IWP values were determined for I4-HPD and I4-MPD, respectively. In the pedo-climatic conditions of Vojvodina and similar regions, we recommend growing maize under the I1-HPDtreatment to achieve high yields. Under the water shortage conditions, the application of I2-HPD treatment is a favorable strategy saving 37 % of irrigation water, while reducing maize grain yield by ∼10 %.

Spatial and temporal variability of meteorological droughts including atmospheric circulation in Central Europe

Drought is one of the natural phenomena influencing many aspects of human activities like water scarcity, food production, agriculture, industry and ecological conditions of the environment. For decades, drought has caused huge financial losses in Europe and around the world. In the area of the Polish Carpathians, there are periods with a deficit of rainwater and increasing frequency of dry months especially in the cold half-year. However, only a limited number of studies exist about the spatial and temporal variability of meteorological drought and the main mechanisms determining its performance in Central Europe. The aim of this work is to perform the spatial and temporal analysis of drought, expressed as SPI, in a heterogenous area of the Polish Carpathian and the highland region in the East-Central part of Europe based on long-term precipitation data. Moreover, for the first time in this work drought characteristics assessed by means of the SPI were discussed considering the atmospheric circulation calendar. In this work monthly precipitation from 55 rainfall stations were analysed from 1961 to 2022. The 3-, 6-, 9-, and 12-month Standardized Precipitation Index (SPI) was used as indicators of meteorological drought. For the 3-month SPI, the main climatic mechanisms determining extreme droughts were defined based on the calendar of synoptic circulations. The Mann-Kendall test was used to detect the trend of extreme droughts. Statistically significant trends of SPI were observed on 52.7% of all analyzed stations and, in most cases, a positive trend was observed, indicating an increase in water resources in the Upper Vistula Basin. Statistically significant trends were more frequently observed in stations located in the western part of the analyzed region. Long-term droughts, represented by the 12-month SPI, occurred in all stations but not in all years. Short-term droughts (3-month SPI) were most frequent in the winter season, 6- and 9-month SPI in winter and spring, and 12-month SPI in winter and autumn. The spatial distribution of droughts was highly diverse. The most intensive drought occurred in 1984, with the 6-month SPI covering 98% of the analyzed region, and the 9- and 12-month SPI covering 90% of the entire region. Droughts exhibit a seasonal pattern, with a dominant 10-year periodicity for all analyzed variants of SPI. Additionally, Fourier analysis revealed a 2-year periodicity for the 3-, 6-, and 9-month SPI and a 31-year periodicity for the 12-month SPI. The results provide insights into the typical climatic conditions in Poland, with strong seasonality in precipitation. The study highlighted that short-term extreme droughts, represented by the 3-month SPI, are often caused by anticyclonic situations with high-pressure wedges Ka and Wa, as observed in 52.3% of cases. These findings are crucial for understanding the spatial and temporal variability of short and long-term extreme droughts in Central Europe, particularly for the agriculture sector which is dominant in the northern part of the analyzed region, where drought frequency is highest.

The Assessment of Precipitation and Droughts in the Aegean Region Using Stochastic Time Series and Standardized Precipitation Index

This study analyzes drought conditions in the Aegean region using monthly precipitation data from nine stations between 1972 and 2020. The Standardized Precipitation Index (SPI) was calculated for 1-, 3-, 6-, 9-, and 12-month periods to evaluate drought conditions at different timescales and station-specific conditions. The results indicate that short-term droughts are more frequent but shorter in duration, while longer periods exhibit fewer but more prolonged droughts. The relative frequency of drought across all periods ranges between 9% and 27%. The İzmir and Denizli stations were highlighted due to their representation of coastal and inner regions, respectively. The findings show that coastal stations, like İzmir, experience more frequent wet years compared to inner stations like Denizli, which have more dry years. Time series linear autoregressive (AR) models, using SPI-12 data, were developed to represent long-term drought trends and forecasts. The best-fitting models were determined using AIC, AICC, FPE, and Var(e) criteria, with AR(2) generally being the most suitable, except for Denizli. This integrated analysis of SPI and AR models provides a robust basis for understanding regional precipitation regimes and predicting future droughts, aiding in the development of effective drought mitigation strategies and water resource management. Future research is anticipated to extend this analysis to encompass all of Turkey and explore various time series models’ applicability.

Increasing drought frequency in the central Zagros Mountains of western Iran over the past two centuries

The Zagros region in western Iran has experienced prolonged drought, significantly impacting water resource and forest ecosystems over the past few centuries. Understanding historical prolonged drought is crucial for making precise forecasts of shifts in regional drought in the Zagros region. Due to the lack of comprehensive historical records, the use of proxy records is considered a valuable tool for reconstructing past drought variations. We aimed to construct a tree-ring chronology of Juniper (Juniperus polycarpus) in the central Zagros region to comprehend its growth response to climate variables. We cored 25 J. polycarpus trees from the Keygooran forest reserve in western Iran and developed the tree ring chronology (1802–2022) using dplR. The relationships between tree growth and climate variables of monthly mean temperature, precipitation, PDSI (Palmer Drought Severity Index), and SPEI (Standardized Precipitation Evapotranspiration Index) were examined. The analysis revealed a strong positive correlation between tree growth and SPEI March-September of 1990–2018 on a 48-month timescale with a 2-year lag (r = 0.61, p < 0.05) which was included in the transfer model. Consequently, the SPEI-48 March-September was reconstructed for the period 1802–2022. On this reconstruction, several extremely dry years in 1832, 1867, and 1876 and extremely wet years in 1807, 1814, 1838, 1850, 1907, and 1908 years were identified, some of them aligning with historical records in Iran. Furthermore, there was a relationship between SPEI-48 March-September and teleconnection events suggesting that certain drought occurrences in the area were associated with the El Niño-Southern Oscillation (ENSO). Consequently, this reconstruction can serve as a reliable proxy for large-scale drought variability in the Zagros region of western Iran. Moreover, our research underscores the utility of SPEI in reconstructing the history of semi-arid climate conditions.

Climate Change and Violent Conflict in the Sahel and Lake Chad Basin

The purpose of this article is to analyse how climate change is a major threat to security in the Sahel and Lake Chad basin. The region is already experiencing the effects of climate change, such as more frequent droughts, floods, and desertification and to expatiate how these effects are leading to food insecurity, water scarcity, and displacement, which are in turn creating conditions that can lead to violent conflict, using the descriptive cum exploratory research design. The paper relied on qualitative data collected from secondary sources. Findings in the paper revealed that, the link between climate change and violent conflict is complex and there are many other factors that contribute to conflict in the region. However, climate change is a major threat that can exacerbate existing tensions and make it more difficult to resolve conflicts peacefully. The paper recommended measures to address the threat of climate change and violent conflict in the Sahel and Lake Chad basin, it is important to take a comprehensive approach that addresses both the root causes of conflict and the effects of climate change: investing in sustainable development and climate adaptation programme, promoting peacebuilding and conflict resolution, providing humanitarian assistance to those affected by climate change and building the resilience of communities to the effects of climate change, by taking a comprehensive approach, which is possible to mitigate the threat of climate change and violent conflict in the Sahel and Lake Chad basin to build a more peaceful and sustainable future for the region.

Performance assessment of indicators of a multi-hazards early warning system in an urban mountain region

The urban basins in the mountainous Andean regions are exposed to rapid and poorly planned urbanization processes, causing drastic changes in the landscape, climate, and hydrology. These factors have led to an intensification in the frequency of floods, landslides, falling trees, and droughts, among many other disasters. Therefore, the city of Manizales has implemented an Early Warning System (EWS) to address emergencies and prevent deaths and damage from some of these disasters. However, these hazards can occur simultaneously, further complicating emergency response efforts and requiring the EWS to address multiple hazards; therefore, it has become the Multi-Hazards Early Warning System (MHEWS), which requires indicators and thresholds to generate alerts within sufficient time. The MHEWS implemented in Manizales addresses initially the hazards of floods and landslides, using indicators and thresholds related to recent rainfall and river levels. This article evaluates these proposed indicators by assessing their forecasting capability, effectiveness, and efficiency in increasing warning times, the alarm duration compared to the event duration, and their forecasting ability based on the location of rainfall triggering floods, landslides and other hazards identify. The analyzed indicators focus on hazards and do not consider exposure or vulnerability in communities. The results indicate that a single hazard indicator is not enough, and including multiple indicators based on complementary sources of information improves the performance of MHEWS in addressing emergencies caused by rain.

Photosynthetic Response to Phosphorus Fertilization in Drought-Stressed Common Beech and Sessile Oak from Different Provenances.

Increasingly frequent and severe droughts pose significant threats to forest ecosystems, particularly affecting photosynthesis, a crucial physiological process for plant growth and biomass production. This study investigates the impact of phosphorus fertilization on the photosynthesis of common beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.). In a common garden experiment, saplings originating from two provenances (wetter KA and drier SB provenances) were exposed to regular watering and drought in interaction with moderate and high phosphorus concentrations in the growing substrate. Results indicated that drought significantly reduced pre-dawn leaf water potential (ΨPD), net photosynthesis (Anet), stomatal conductance (gs) and photosynthetic performance index (PIabs) in both species. Phosphorus fertilization had a negative impact on Anet and PIabs, thus exacerbating the negative impact of drought on photosynthetic efficiency, potentially due to excessive phosphorus absorption by saplings. Provenance differences were notable, with the KA provenance showing better drought resilience. This research highlights the complexity of nutrient-drought interactions and underscores the need for cautious application of fertilization strategies in reforestation efforts under changing climatic conditions.