An Assessment of Woody Plant Water Source Studies from across the Globe: What Do We Know after 30 Years of Research and Where Do We Go from Here?

Abstract

In the face of global climate change, water availability and its impact on forest productivity is becoming an increasingly important issue. It is therefore necessary to evaluate the advancement of research in this field and to set new research priorities. A systematic literature review was performed to evaluate the spatiotemporal dynamics of global research on woody plant water sources and to determine a future research agenda. Most of the reviewed studies were from the United States, followed by China and Australia. The research indicates that there is a clear variation in woody plant water sources in forests due to season, climate, leaf phenology, and method of measurement. Much of the research focus has been on identifying plant water sources using a single isotope approach. Much less focus has been given to the nexus between water source and tree size, tree growth, drought, water use efficiency, agroforestry systems, groundwater interactions, and many other topics. Therefore, a new set of research priorities has been proposed that will address these gaps under different vegetation and climate conditions. Once these issues are resolved, the research can inform forest process studies in new ways.

Sap flux and stable isotopes of water show contrasting tree water uptake strategies in two co‐occurring tropical rainforest tree species

“…In this regard, existing water extraction method and analysing techniques also has limitations (Millar et al, 2022). As different researchers employ varying methods, there is an immediate need for standardization in the investigation of plant water sources (Millar et al, 2022; Sohel et al, 2019). More research on evaporative enrichment using the dual isotope approach is needed for better understanding of isotope composition dynamics during transpiration.…”

Research hotspot and trend of plant water use in karst: A bibliometric analysis from 1984 to 2022

“…To ensure that all aspects are fully represented in the keyword search, we included three search strings, as follows: TS=(vegetation OR plant OR plants OR forest OR tree OR trees OR plant OR planted OR reforest OR afforest OR "mixed plantation" OR agroforest OR "grassland" OR grass OR turf OR meadow OR shrubs OR bush OR coppice ) AND TS=("water source" OR "water use" OR "water e ciency" OR ecohydrology OR "plant ecophysiology") AND TS=(carbonate OR limestone OR dolomite OR dolostone OR karst OR karstic NOT "Picea abies Karst" NOT "Picea abies (L.) Karst"). The keywords were chosen based on previous literature reviews on similar topics, the authors' own research experience, and the views of experts from this eld (Sohel et al, 2019). The plant-related content yielded by the terms "ecohydrology" and "plant ecophysiology" will contain information on plant water use (Urli et al, 2013).…”

“…In this study, we used the VOSviewer analysis software package to analyze the current status and hotspots of plant water use research in karst areas, and used Origin2021 to analyze the overall posting trends and numbers of high-frequency keywords (Rabbani et al, 2021;Sohel et al, 2019). This paper analyzes the number of publications each year, as well as the keywords, citations, journal of publication, authors, countries and institutions of each article, and we used this information to analyze research trends, determine leading journals, undertake keyword co-occurrence analysis and co-citation analysis, and derive author, country and institutional cooperation networks relating to plant water use in karst regions.…”

Assessment of Carbon Sequestration in Private Forests across Two Different Physiographic Regions of Nepal: Implications for Conservation and Climate Change Mitigation

“…Forests can efectively capture and store atmospheric carbon in both aboveground and belowground biomass through photosynthesis. Forests also have a vital role in the climate system [5], serving as both sources and sinks of carbon on a global scale [6,7]. Te growth of forests is believed to have signifcant potential for carbon sequestration and is considered a cost-efective approach to mitigating global climate change [8][9][10].…”