Fire and water: global fire impacts on physicochemical properties of freshwater ecosystems

doi:10.21203/rs.3.rs-1233463/v1

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Fire and water: global fire impacts on physicochemical properties of freshwater ecosystems

https://doi.org/10.21203/rs.3.rs-1233463/v1

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Freshwater ecosystems are intensely endangered, entailing declines in the biodiversity and ecosystem services. Fire may affect physicochemical water quality parameters of these environments by transference of ash and toxic substances into water bodies, altering nutrient and oxygen concentrations, temperature or turbidity. However, major knowledge gaps in the impacts of fire on freshwater habitats are prevalent. We conducted a global systematic review by searching articles in the Web of Science related to the impacts of fire on the physicochemical water properties of freshwater ecosystems. We estimated ecological and geographic biases, quantified the set of physicochemical parameters investigated, and provided an overview of fire-mediated alterations. We found 54 articles published between 1976 and 2019, with a significant increase during the last decade. Research was strongly biased towards a few western countries, mostly across North America, Europe and Australia. Lotic systems were considerably more studied than lentic systems. Overall, 57 chemical and 17 physical parameters were evaluated, comprising 304 and 77 cases, respectively. Fire altered 68% of the cases studied and this alteration was proportionally similar between chemical (66%) and physical (75%) properties. Nutrient concentration, metal ions, alkalinity, turbidity and temperature were recurrently increased parameters by fire, whereas oxygen mostly decreased. Our study demonstrates that fire commonly affects water quality parameters of freshwater ecosystems. Biases and resulting gaps may steer future sampling efforts and promote a broader understanding of the impacts of fire on these environments. Our results may ultimately guide applicable conservation policies for biodiversity and water management strategies of freshwater habitats.

Alterations of water properties

chemical water parameters

indirect effects of fire

knowledge gaps

physical water parameters

water quality

Fire causes large disruptions and changes in the diversity, functioning and services of many ecosystems (Kelly et al. 2020; Shakesby and Doerr 2006). Burning of vegetation has become increasingly more frequent, intense and severe in recent decades (Halofsky et al. 2020; Jolly et al. 2015; Pausas and Keeley 2009; but see Andela et al. 2017 for savannas and grasslands). While the effects of fire are broadly studied across different terrestrial ecosystems worldwide (Pausas and Ribeiro 2017), their effects on aquatic ecosystems are relatively less known (Bixby et al. 2015). However, the disturbance of vegetation and soil structure related to fire may severely alter the local microclimate, the hydrological processes and water quality of aquatic environments (e.g., Gustine et al., 2021; Pettit and Naiman 2007; Smith et al. 2011; Townsend and Douglas 2004). Ultimately, fire-induced impacts on aquatic habitats may produce major perturbation on their biodiversity, dynamic and structure (Bixby et al. 2015).

Continental aquatic ecosystems (i.e., freshwater ecosystems) are among the most diverse ecological communities worldwide and provide essential services to human societies, yet they are intensely endangered environments with an increased loss of biodiversity and ecosystem services (e.g., Baggio et al. 2021; Dudgeon et al. 2006; Harrison et al. 2018; Reid et al. 2019; Vörösmarty et al. 2010). However, major knowledge gaps in biodiversity and ecosystem functioning of freshwater environments are noticeable, because of a strong bias toward marine and terrestrial ecosystems in biological samplings and conservation research (Barros et al. 2020; Carrizo et al. 2017; Clark and May 2002; Darwall et al. 2011). Determining sampling biases and knowledge gaps in fire-related research of these vulnerable aquatic habitats is crucial to steer future research efforts and provide suitable conservation policies.

In freshwater ecosystems, fires cause direct effects by reducing surrounding (e.g., riparian forest) or interspersed (e.g., wetland) vegetation, and altering biological and physicochemical soil properties. Bordering soil and vegetation provide essential ecosystem functions to freshwater habitats, buffering nutrient discharge, avoiding excessive erosion and sedimentation, and subsequently preventing the entry of waste and allochthonous material (Boerner et al. 2009; Lathrop 1994; Pereira et al. 2019; Townsend and Douglas 2004). Fire-driven soil and vegetation alteration may thus cause indirect effects on freshwater ecosystems. Indirect effects are mostly related to changes in the local microclimate and the transfer of ash and toxic substances into water bodies, inducing shifts in the physicochemical characteristics of water (i.e., water quality parameters), such as increased nutrients, sediments, temperature, turbidity, alkalinity and electrical conductivity, or a decrease, for example, in dissolved oxygen (Belillas and Rodà 1993; Brito et al. 2021; Carignan and Lamontagne 2000; Hitt 2003; Hohner et al. 2016; Smith et al. 2011). These changes can ultimately stimulate the proliferation of primary producers such as phytoplankton, periphyton and macrophytes, promoting the eutrophication of freshwater ecosystems, that in turn affects water quality and biological integrity (Carignan and Lamontagne 2000; Monaghan et al. 2019; Oliver et al. 2012; Rhea et al. 2021). Altogether, fire-related hydrological changes can lead to the mortality of aquatic biota, including plant communities, plankton, macroinvertebrates and fishes (Carvalho et al. 2019; Hitt 2003; Silva et al. 2015). Likewise, such changes may entail major restrictions on water availability and demand for agricultural, domestic and industrial purposes (Baggio et al. 2021; Emelko et al. 2011; Hallema et al. 2018). Understanding the effect of fire on water quality parameters in freshwater ecosystems can help to guide more targeted and applicable conservation actions on these vulnerable environments, their associated biodiversity, and water needs for humans.

In this study, we aim to provide a comprehensive and critical global systematic review related to the effect of fire on water quality in freshwater ecosystems. We considered fires in a broad sense, including wildfires (i.e., natural and human-sparked) and controlled fires (i.e., prescribed and experimental). To do this, we conducted an exhaustive literature review of the publications about this topic. Physical and chemical water parameters may be differentially affected by fire and generate diverse impacts on aquatic biota (Bixby et al. 2015; Rust et al. 2019; Smith et al. 2011). Consequently, the identification of gaps and the variation in the response of water quality parameters to fire are also crucial to provide useful information to better support conservation decisions. Specifically, our objectives were to: (1) estimate biases and gaps in the ecological and geographic patterns of water quality parameters investigated; and (2) provide an overview of the impact of fire on the physical and chemical parameters of water quality.

Data source and collection

We searched the articles evaluating the effects of fire on water quality parameters of freshwater ecosystems in the Web of Science database (ISI Web of Knowledge – http://apps.webofknowledge.com; hereafter, WOS) on 26 November 2019. Our survey included high-sensitivity and low-specificity terms (see Pullin and Stewart 2006) related to this topic. Thus, we searched for ("water quality" OR “water component*” OR “water parameter*” OR “water propert*”) AND (*fire* OR soot* OR ash* OR smoke* OR burn* OR combustion*) AND (freshwater OR “aquatic ecosystem*”) anywhere in the full record by using the “All fields” (ALL) field tag. We considered all articles provided at the time of the survey (most recent papers from December 2019).

Our review exclusively focused on studies related to the effect of fire on water quality parameters (1) in freshwater ecosystems as study area, (2) considering natural, human-started, prescribed or experimental fires, (3) published in scientific articles, and (4) reporting the effects based on statistical tests (e.g., generalised linear models) or ordination methods (e.g., correspondence analysis). Thus, we excluded articles from marine environments, reviews, meta-analyses and modelling, and publications that did not provide information on water quality parameters (e.g., indirect effects of fire on aquatic biota), that evaluated the effect of transfer of ashes and toxic substances unrelated to fire on water quality (e.g., volcanic eruptions), and that showed the impacts of fire in a different context (e.g., paleoecological studies).

From the selected articles, we extracted the following information: (1) year of the publication, (2) country where the study was conducted, (3) type of studied aquatic environment: lotic or lentic, (4) fire origin: wildfire (natural or human-started), prescribed or experimental, (5) water quality parameter(s) recorded, (6) category(ies) of the water quality parameter(s) recorded: physical or chemical (Omer 2019), and (7) response to fire of the water quality parameter(s) recorded: altered (significant increase or decrease) or unaltered (non-significant differences). Most articles conducted statistical analyses for multiple water quality parameters, so each relationship studied between a particular parameter and a specific response within an article was termed as a case, the sample unit in our database.

Data analysis

To test differences in the frequency of responses to fire between physical and chemical water quality parameters, we analysed a contingency table considering the category of the water quality parameter recorded (2 rows; physical or chemical) × altered/unaltered responses of each water parameter (2 columns). We analysed significant departures from expected frequencies with the Fisher exact test, performed with R software (R Development Core Team 2020). Contingency tables allow the inclusion of the simplest and standard response that can be extracted from the articles (altered –increase, decrease– and unaltered –neutral–; see Teixido et al. 2021). Thus, we included as many studies as possible in our assessment, and the many different ways in which results were reported, by testing for significant differences in the observed frequency of the responses of water quality parameters to fire.

Global research patterns

We found 54 articles published between 1976 and 2019 studying the effects of fire on physical and chemical water quality parameters of freshwater ecosystems (Supplementary Information). The number of publications positively increased over time (Fig. 1). This increase was sizable in the last decade; whereas from 1976 to 2009 the number of published articles was relatively low (18 studies; mean ± SE = 1.1 ± 0.6 studies per year), publications were doubled between 2010 and 2019 (36 studies; mean ± SE = 3.2 ± 1.7 studies per year). Research showed a clear bias towards the West and extensive geographic gaps. Studies were only conducted across nine countries and the Latin American region was overlooked (Fig. 2). The United States comprised the highest percentage of publications (51%), followed by Australia (20%), Portugal (9%), Canada (6%), Singapore and the United Kingdom (4% each), and Russia, South Africa and Spain (2% each, corresponding with one article).

The lotic systems, including rivers, streams and hydrographic basins were the environments with the highest number of studies (78%), whereas research in lentic systems was conducted in 20% of the publications. Only one article included both lentic and lotic environments (2% of the total). Most of the publications considered wildfires (72%), while studies addressing the effects of prescribed or controlled fire accounted for 20% of research. Only 8% of the studies represented the effect of experimental fire, conducted either in the field or the laboratory.

Effects of fire on water quality parameters

Overall, 57 chemical and 17 physical water quality parameters were evaluated. Accordingly, the number of cases reported for chemical parameters (304) was about 4-times higher than for physical parameters (77) (Table 1). Among the 57 chemical parameters analysed, ten comprised about 60% of the 304 cases studied: nitrate (28 cases), total phosphorus (24), total nitrogen (23), ammonium (17), pH (17), calcium (16), magnesium (16), potassium (15), sodium (15) and dissolved organic carbon (13). For the physical parameters, electric conductivity (19 cases), turbidity (15), temperature (11) and total suspended solids (11) comprised about 75% of the cases (Table 1).

On average, fire altered ca. 68% of the cases reported for all water quality parameters and this alteration was proportionally similar between chemical and physical properties (66% vs 75%; Fisher exact test: P = 0.134; Fig. 3). Among the chemical parameters, the concentration of nutrients (nitrate, total nitrogen, total phosphorus), metal ions (aluminium, iron), alkalinity and dissolved organic carbon were the most frequently increased parameters by fire, whereas dissolved oxygen mostly decreased. On the other hand, nutrient metal ions (calcium, magnesium, potassium, sodium), nutrient salts (ammonium, phosphate, sulphate) and pH showed similar frequencies of altered and unaltered responses to fire (Table 1). Fire-induced alterations of physical parameters were mostly mediated by increases in electrical conductivity, turbidity, total suspended solids, temperature and sediment concentration. Otherwise, depth, Secchi transparency and substrate diameter decreased, although these parameters were only reported by one case (Table 1).

Global research patterns

The low number of publications analysed in our review shows that the impacts of fire on freshwater ecosystems are less considered when compared to the effects on functioning, soil properties and biodiversity of terrestrial environments (e.g., Butler et al. 2018; Pastro et al. 2014; Vasconcelos et al. 2017; Wan et al. 2001). Moreover, a growing body of studies has reviewed the effects of fire on composition, structure and transformation of terrestrial ecosystems and their biodiversity (e.g., Certini et al. 2021; González-Pérez et al. 2004; He et al. 2019; Kelly et al. 2020; Santín and Doerr 2016). Our study encompasses a global synthesis of the current state of knowledge and impacts of fire on freshwater ecosystems, adding new insights to the underrepresentation of studies about fire and aquatic environments (Brixby et al. 2015). However, the temporal distribution of studies revealed a disproportionate increase in the publications during the last decade. Concern about the risks of the increased frequency and severity of wildfires to water supply is growing across the scientific community (Robinne et al. 2021). The widespread interest over recent years on the impacts of fire is related to climate-associated perturbations, such as high temperatures and prolonged droughts, where substantial increases in the probability of wildfires and area of burned vegetation are expected (Jolly et al. 2015; Robinne et al. 2021). Impacts of fire intensity on freshwater ecosystems based on climate change projections include alterations on the structure and resilience of these environments, recreational use of water bodies, and drinking water treatment (Loiselle et al. 2020). Under the unceasing global warming scenario and resulting water availability, we encourage the scientific community to broaden knowledge of fire impacts on freshwater systems.

We found major gaps in the global distribution of studies, mostly concentrated in North America, Australia and a few European countries. Geographic biases are pervasive issues in ecology and conservation biology that result in oversampled areas, countries and ecosystems (Cook et al. 2013; Nuñez et al. 2021). Some non-exclusive reasons are feasible to account for the predominance of fire-related studies across the reported regions, associated with more research institutions, science investment, native English speak and fire intensity. Overall, ecological research is disproportionately skewed to western or economically developed countries, especially to the United States (Nuñez et al. 2021). In parallel, the dominance of studies for this country may be induced by the general increase of burned area in the last decades due to high fuel loads (i.e., plant material), human-population growth in urban areas, and climate change (Doerr and Santín 2013). In the United States, wildfires between 1984 and 2014 affected approximately 6% of the total length of lotic ecosystems, becoming one of the major drivers of deterioration of freshwater systems (Ball et al. 2021). Moreover, both the United States and Canada are listed among the countries most affected by wildfire events and subsequent economic damage recorded (Doerr and Santín 2013). Similarly, Australia is constantly affected by wildfires, which are expected to increase due to global warming (Yu et al. 2020). Fires in this country largely deteriorate the soil, water and air quality, with severe impacts on biodiversity and water supply (Silva et al. 2020). Across the European countries, Portugal, Russia and Spain are traditionally three of the most affected countries by wildfires (Doerr and Santín 2013; Migiro 2018). Specifically, Portugal and Russia record an annual average of ca. 18,000 fires and, in 2016, fires destroyed about 10% of Portugal's forests and 2.5 M ha of protected areas in Russia (Migiro 2018).

Still, some regions of the world extensively prone to wildfires such as Central and South America, Sub-Saharan Africa and Southern Asia (see Fig. 4 in Doerr and Santín 2013; see also historical records at https://firms.modaps.eosdis.nasa.gov/map) were overlooked. The deficiency of studies in these regions is worrying not only in terms of aquatic wildlife conservation, but also for human needs. Neglected research may lead to less assertive institutional responses and decision makings about water conservation and supply, while hydric requirements are incessantly increasing and water availability decreasing, especially in water-deficit countries from Africa and Asia (Baggio et al. 2021; Leal Filho et al. 2022). However, the interplay between hydrographic characteristics and scientific logistics of some countries may be suitable to encourage researchers to conduct fire-related studies and, ultimately, understand the impacts of fire on freshwater ecosystems in the neglected regions. For example, Brazil, China and India are among the ten countries with the most freshwater bodies and resources (Gleick et al. 2006; Misachi 2018) and with an advanced and growing ecological research in terms of articles published (Nuñez et al. 2021). We call future studies to consider the impacts of fire on freshwater ecosystems across neglected regions of Latin America, Africa and Asia, and encourage the scientific community of leading countries such as Brazil, China and India to promote this research.

We also recorded ecological biases based on the freshwater environments evaluated, as lotic systems (e.g., rivers) were mostly considered in relation to lentic systems (e.g., lakes). Although lentic systems cover a much greater volume of freshwater on Earth than lotic systems (ca. 43:1; Shiklomanov 1993; USGS 2013), research on ecology and biodiversity is commonly biased to rivers and streams when compared to lakes and other lentic environments (e.g., Veach et al. 2021; Wurtsbaugh et al. 2015). Although the responses to the effect of fire on water quality may be similar in both environments (e.g., nutrients and temperature; Naylor et al. 2012; Sundarambal et al. 2010), fire effects on lentic watersheds have not still been properly addressed and require further consideration (McCullough et al. 2019). We therefore propose additional sampling efforts on lakes and other lentic systems to improve our knowledge of how fire may impact the physicochemical characteristics of these ecosystems in a changing world.

Effects of fire on water quality parameters

Water is an essential resource and its quality classified according to physical, chemical and biological characteristics, establishing environmental change-sensitive parameters (Omer 2019). However, the quality of water attributed to freshwater ecosystems is very dynamic and variable over time, space and use of this resource (Wyk and Scarpa 1999). For example, although the same set of parameters can be utilised to characterise water quality across different environments (e.g., ponds, rivers, lakes), similar parameter values would be unexpected. In brief, water quality is intrinsically associated with its use, region and environment of origin, with variable parameters associated with human activities and the functionality and conservation of aquatic ecosystems (Brooks et al. 2015; Keeler et al. 2012; Wyk and Scarpa 1999). In this review, we compiled an extensive set of water quality parameters, mostly chemical, used to capture their sensitivity to fire, linking a typically terrestrial disturbance to freshwater ecosystems. From this set, a few parameters were mostly used as chemical water properties in the studies, especially nitrogen and phosphorus. Publications considering these nutrients essential in freshwater systems cover a broad range of scopes beyond fire impact, from drinking water quality (e.g., Nieder et al. 2018) to trophic status (e.g., Sager 2009). Across the physical variables, electrical conductivity and temperature were recurrent, as these are relevant parameters for ecosystem functioning and widely used in environmental monitoring of aquatic habitats (Hayashi 2004).

Interestingly, physical and chemical water quality parameters were equally vulnerable to the effects of fire. Our results also revealed a predominance of increased responses of these parameters following wildfires (e.g., metal ions, nutrient concentration, temperature, turbidity). In limnological terms, increases in chemical parameters such as nutrient concentrations, metal ions, dissolved organic carbon, and subsequent increases in alkalinity derived from sediment fluxes, runoff and ash deposition after fires, are also associated with decreases in dissolved oxygen, as well as higher values of several physical parameters as electrical conductivity, sediment concentration, temperature, total solids and turbidity (Brito et al. 2021; Hohner et al. 2016; Smith et al. 2011). Wildfires are a major driver of nitrogen cycling and its export from terrestrial to aquatic systems, consequently degrading water quality (Gustine et al. 2021). High fire-mediated concentrations of nitrogenous compounds in freshwater ecosystems can remain elevated for decades. Thus, the transfer of nutrients (e.g., nitrate) into these environments may ultimately exceed the demand of the biota, increasing their susceptibility to eutrophication and harmful algal blooms until the recovery of terrestrial vegetation, when plant demand for nutrients reduces nitrogen availability (Rhea et al. 2021). Subsequently, eutrophication of freshwater ecosystems and proliferation of primary producers may largely affect water quality by decreasing dissolved oxygen and light absorbance, or increasing temperature and turbidity (Carignan and Lamontagne 2000; Monaghan et al. 2019; Oliver et al. 2012). Therefore, the set of physicochemical properties of freshwater ecosystems are interconnected and mutually dependent water quality parameters mostly sensitive to and indirectly affected by fire. Evaluating the interplay between these chemical and physical characteristics following wildfires is crucial to fully understand the functioning, resilience and vulnerability of continental aquatic environments worldwide.

Implications for biodiversity and human needs

Alterations in water physicochemical conditions following fire can lead to freshwater pollution and subsequent changes in aquatic biota and ecosystem services. For example, fire causes short-term declines in microalgae and periphyton communities due to accumulations of contaminants and polycyclic aromatic hydrocarbons (Silva et al. 2015). However, benthic algae populations have a long-term potential to recolonize and increase following fire disturbance (Rugenski and Minshall 2014). The effects of fire-mediated environmental disturbance reduce both the biomass and the composition of decomposer organisms, such as bacteria and aquatic fungi, and therefore indirectly affect the trophic networks of aquatic ecosystems (Carvalho et al. 2019). Similarly, chemical composition and toxicity of fire-produced ashes induce acute immobility of zooplankton (Harper et al. 2019). In addition, fire impacts commonly affect macroinvertebrate diversity, replacing rare species by tolerant, more generalist, species (Monaghan et al. 2019; Xu et al. 2014). Post-fire runoff also causes anomalies in the feeding behaviour of shredder macroinvertebrates, consequently affecting ecological processes, since aquatic shredders play an important role in detritus-based food webs of lotic ecosystems (Pradhan et al. 2020). Likewise, the experimental exposure to an aqueous extract of ash solutions increases the mortality rates of a mollusc species (Silva et al. 2016). For fishes, fire-induced water toxicity negatively affects resource-specialist stream species (e.g., Salmo trutta), whereas generalist cyprinids remain unaltered (Monaghan et al. 2016). In fact, fishes can interestingly be fire-resilient, decreasing abundance and recolonizing the river after years from the disturbance (Caldwell et al. 2013; Dudham et al. 2007). Other indirect effects of fire on fish assemblages include increased water temperatures and turbidity, resulting in declines of trout populations (Hitt 2003; Rust et al. 2019).

Otherwise, less is known about the effects of fire on herpetofauna, birds and mammals that use or temporarily inhabit freshwater ecosystems, regardless of being permanent-resident species. The impacts of fire on amphibians are spatially and temporally variable, and mostly focused on terrestrial species or terrestrial life stages of aquatic breeding species (Hossack and Pilliod 2011; Pilliod et al. 2003). Still, evidence shows that stream amphibian species are more negatively affected by fire than terrestrial amphibians (Bury 2004). More recent studies have also demonstrated that breeding occurrence and species richness significantly decline across rivers and streams after fire (Larson 2014; Muñoz et al. 2019). For reptiles, Lovich et al. (2017) recorded high mortality rates in the southwestern pond turtle related to low levels of dissolved oxygen and high salinity in a lake in California following a large wildfire. Piscivorous and water-feeding birds and mammals may also indirectly suffer the impacts that fire causes on water physicochemical conditions of rivers and lakes. For example, high fire-related mercury concentrations have been found in both herring gull eggs (Hebert et al. 2021) and semi-aquatic mustelid fur and stomach content (Eccles et al. 2020). However, prescribed fire enhanced foraging success and prey captures of long-legged wading birds in a grass-dominated wetland by creating burned areas with short-term shallow water habitats (Venne and Frederick 2013). We suggest that further water-fire research on semi-aquatic and non-fish aquatic vertebrates would be recommended to ultimately improve our understanding of how fire indirectly impacts top trophic levels, food webs and ecological complexity of freshwater ecosystems.

An extensive array of ecosystem services may be affected by fire, among which water quantity, soil retention, pest management and natural hazard regulation have been largely considered (Vukomanovic and Steelman 2019). For freshwater ecosystem services, major concerns of the impacts of fire are focused on water availability and demands for human requirements (e.g., Hallema et al. 2018; Robinne et al. 2018; Robinne et al. 2021). Constant declines in water quantity and quality have become a growing global challenge to human health and sustainable development, especially under the projected drought scenarios associated with climate change and the exponential population growth (Baggio et al. 2021; Emelko et al. 2011; Hallema et al. 2018). Following fire, the increased concentrations of contaminants and toxic constituents (e.g., arsenic, cyanides, heavy metals) and alterations in the composition of organic matter deposited in watersheds, which can form disinfection by-products related to cancer and reproductive development during water treatment process, impact drinking water supplies (e.g., Hohner et al. 2016; Pennino et al. 2022; Smith et al. 2011). Although wildfires can endanger potable water resources, little is still known about the global assessment of the impacts on water supplies. This is particularly important to achieve the Agenda 2030’s Goal 6, that seeks to protect and restore freshwater ecosystems, increase water quality, reduce the number of people suffering from water scarcity, and achieve universal and equitable access to drinking water (UN General Assembly 2015).

Our study demonstrates that fire frequently affects water quality parameters of freshwater ecosystems. A broad set of chemical and physical parameters were analysed, which were altered by fire in similar proportions. However, fire-mediated effects on freshwater ecosystems are still poorly considered in relation to terrestrial environments and research strongly biased towards a few western countries. Freshwater ecosystems harbour a large biodiversity worldwide, but are habitats highly vulnerable to anthropogenic actions that are increasingly undergoing the impacts of global environmental change. Our review brings key findings to steer future sampling efforts and subsequently promote a more in-depth understanding of the impacts of fire on freshwater ecosystems. Overall, considering the biased research and the flawed knowledge on the effects of fire on water quality of freshwater ecosystems and subsequent impacts on biodiversity and human needs, the persistent vulnerability of these environments under the climate change scenarios, and the exponential human population growth, is essential to ensure sustainable development, fostering progress while protecting the freshwater systems. Our results may ultimately guide applicable conservation policies for wildlife, water management strategies and sustainability of these environments.

Acknowledgements

We thank Thiago J. Izzo for the suggestions provided during the earlier versions of the manuscript. We are also grateful to Gisele F. P. Assis and Josilene S. Santos for their contributions on article selection.

Declarations

Funding

The National Coordination for the Improvement of Higher Education Personnel – Brazil (CAPES) – Finance Code 001, granted doctoral scholarships to JJM, NDSP and ACMS.

Competing interests

We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. Our research is based on data from literature, so we confirm that did not conduct any work with wild or captive animals. Therefore, no ethical policy relative to conservation considerations is applicable (e.g. BOU ethical policy).

Data availability statement

The raw data that support the findings of this study will be available in a repository once the article is accepted. The references used in this review are available within the supplementary information file.

Andela N, Morton DC, Giglio L, Chen Y, Van der Werf GR, Kasibhatla PS, DeFries RS et al (2017) A human-driven decline in global burned area. Science 356:1356-1362. https://doi.org/10.1126/science.aal4108

Baggio G, Qadir M, Smakhtin V (2021) Freshwater availability status across countries for human and ecosystem needs. Sci Total Environ 792:148230. https://doi:10.1016/j.scitotenv.2021.1482

Ball G, Regier P, González-Pinzón R, Reale J, Van Horn D (2021) Wildfires increasingly impact western US fluvial networks. Nat Commun 12:1-8. https://doi.org/10.1038/s41467-021-22747-3

Barros G, da Silva Brito MT, Peluso LM, de Faria É, Izzo TJ, Teixido AL (2020) Biased research generates large gaps on invertebrate biota knowledge in Brazilian freshwater ecosystems. Perspect Ecol Conserv 18:190-196. https://doi.org/10.1016/j.pecon.2020.06.003

Belillas CM, Rodà F (1993) The effects of fire on water quality, dissolved nutrient losses and the export of particulate matter from dry heathland catchments. J Hydrol 150:1-17. https://doi.org/10.1016/0022-1694(93)90153-Z

Bixby RJ, Cooper SD, Gresswell RE, Brown LE, Dahm CN, Dwire KA (2015) Fire effects on aquatic ecosystems: an assessment of the current state of the science. Freshw Sci 34:1340-1350. https://doi.org/10.1086/684073

Boerner RE, Huang J, Hart SC (2009) Impacts of Fire and Fire Surrogate treatments on forest soil properties: a meta‐analytical approach. Ecol Appl 19:338-358. https://doi.org/10.1890/07-1767.1

Brito DQ, Santos LH, Passos CJ, Oliveira-Filho EC (2021) Short‐term effects of wildfire ash on water quality parameters: a laboratory approach. Bull Environ Contam Toxicol 107:500-505. https://doi.org/10.1007/s00128-021-03220-9

Brooks BW, Lazorchak JM, Howard MD, Johnson MV, Morton SL, Perkins DA, Reavie ED et al (2015) Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems? Environ Toxicol Chem 35:6-13. https://doi.org/10.1002/etc.3220

Bury RB (2004) Wildfire, fuel reduction, and herpetofaunas across diverse landscape mosaics in northwestern forests. Conserv Biol 18:968-975. https://doi.org/10.1111/j.1523-1739.2004.00522.x

Butler OM, Elser JJ, Lewis T, Mackey B, Chen C (2018) The phosphorus-rich signature of fire in the soil-plant system: a global meta-analysis. Ecol Lett 21:335-344. https://doi.org/10.1111/ele.12896

Caldwell CA, Jacobi GZ, Anderson MC, Parmenter RR, McGann J, Gould WR, DuBey R et al (2013) Prescribed-fire effects on an aquatic community of a southwest montane grassland system. N Am J Fish Manag 33:1049-1062. https://doi.org/10.1080/02755947.2013.824934

Carignan R. D'Arcy P, Lamontagne S (2000) Comparative impacts of fire and forest harvesting on water quality in Boreal Shield lakes. Can J Fish Aquat 57:105-117. https://doi.org/10.1139/f00-125

Carrizo SF, Lengyel S, Kapusi F, Szabolcs M, Kasperidus HD, Scholz M, Markovic D et al (2017) Critical catchments for freshwater biodiversity conservation in Europe: identification, prioritisation and gap analysis. J Appl Ecol 54:1209-1218. https://doi.org/10.1111/1365-2664.12842

Carvalho F, Pradhan A, Abrantes N, Campos I, Keizer JJ, Cássio F, Pascoal C (2019) Wildfire impacts on freshwater detrital food webs depend on runoff load, exposure time and burnt forest type. Sci Total Environ 692:691-700. https://doi.org/10.1016/j.scitotenv.2019.07.265

Certini G, Moya D, Lucas-Borja ME, Mastrolonardo G (2021) The impact of fire on soil-dwelling biota: A review. For Ecol Manag 488:118989. https://doi.org/10.1016/j.foreco.2021.118989

Clark JA, May RM (2002) Taxonomic bias in conservation research. Science 297:191-193. https://doi.org/10.1126/science.297.5579.191b

Cook CN, Possingham HP, Fuller RA (2013) Contribution of systematic reviews to management decisions. Conserv Biol 27:902-915. https://doi.org/10.1111/cobi.12114

Darwall WR, Holland RA, Smith KG, Allen D, Brooks EG, Katarya V, Pollock CM et al (2011) Implications of bias in conservation research and investment for freshwater species. Conserv Lett 4:474-482. https://doi.org/10.1111/j.1755-263X.2011.00202.x

Doerr SH, Santín C (2013) Wildfire: A burning issue for insurers? Global fire patterns, trends, impacts and perceptions. Lloyd’s, London

Dudgeon D, Arthington AH, Gessner MO, Kawabata ZI, Knowler DJ, Lévêque C, Naiman RJ et al (2006) Freshwater biodiversity: importance, threats, status and conservation challenges. Biol Rev 81:163-182. https://doi.org/10.1017/S1464793105006950

Dunham JB, Rosenberger AE, Luce CH, Rieman BE (2007) Influences of wildfire and channel reorganization on spatial and temporal variation in stream temperature and the distribution of fish and amphibians. Ecosystems 10:335-346. https://doi.org/10.1007/s10021-007-9029-8

Eccles KM, Thomas PJ, Chan HM (2020) Relationships between mercury concentrations in fur and stomach contents of river otter (Lontra canadensis) and mink (Neovison vison) in Northern Alberta Canada and their applications as proxies for environmental factors determining mercury bioavailability. Environ Res 181:108961. https://doi.org/ 10.1016/j.envres.2019.108961

Emelko MB, Silins U, Bladon KD, Stone M (2011) Implications of land disturbance on drinking water treatability in a changing climate: demonstrating the need for “source water supply and protection” strategies. Water Res 45:461-472. https://doi.org/10.1016/j.watres.2010.08.051

Gleick PH, Wolff GH, Cooley H, Palaniappan M, Samulon A, Lee E, Morrison J et al (2006) The world’s water 2006-2007. The biennial report on freshwater resources. Island Press, Washington

González-Pérez JA, González-Vila FJ, Almendros G, Knicker H (2004) The effect of fire on soil organic matter–a review. Environ Int 30:855-870. https://doi.org/10.1016/j.envint.2004.02.003

Gustine RN, Hanan EJ, Robichaud PR, Elliot WJ (2021) From burned slopes to streams: how wildfire affects nitrogen cycling and retention in forests and fire-prone watersheds. Biogeochemistry 157:51-68. https://doi.org/10.1007/s10533-021-00861-0

Hallema DW, Robinne FN, Bladon KD (2018) Reframing the challenge of global wildfire threats to water supplies. Earth's Future 6:772-776. https://doi.org/10.1029/2018ef000867

Halofsky JE, Peterson DL, Harvey BJ (2020) Changing wildfire, changing forests: the effects of climate change on fire regimes and vegetation in the Pacific Northwest, USA. Fire Ecol 16:1-26. https://doi.org/10.1186/s42408-019-0062-8

Harper AR, Santin C, Doerr SH, Froyd CA, Albini D, Otero XL, Viñas L et al (2019) Chemical composition of wildfire ash produced in contrasting ecosystems and its toxicity to Daphnia magna. International Journal of Wildland Fire 28:726. https://doi.org/10.1071/wf18200

Harrison I, Abell R, Darwall W, Thieme ML, Tickner D, Timboe I (2018) The freshwater biodiversity crisis. Science 362:1369-1369. https://doi.org/10.1126/science.aav9242

Hayashi M (2004) Temperature-electrical conductivity relation of water for environmental monitoring and geophysical data inversion. Environmental Monitoring and Assessment 96:119-128. https://doi.org/10.1023/b:emas.0000031719.83065.68

He T, Lamont BB, Pausas JG (2019) Fire as a key driver of Earth's biodiversity. Biol Rev 94:1983-2010. https://doi.org/10.1111/brv.12544

Hebert CE, Chételat J, Beck R, Dolgova S, Fordy K, Kirby P, Martin P et al (2021) Inter-annual variation of mercury in aquatic bird eggs and fish from a large subarctic lake under a warming climate. Sci Total Environ 766:144614. https://doi.org/10.1016/j.scitotenv.2020.144614

Hitt NP (2003) Immediate effects of wildfire on stream temperature. Journal of Freshwater Ecology 18:171-173. https://doi.org/10.1080/02705060.2003.9663964

Hohner AK, Cawley K, Oropeza J, Summers RS, Rosario-Ortiz FL (2016) Drinking water treatment response following a Colorado wildfire. Water Res 105:187-198. https://doi.org/10.1016/j.watres.2016.08.034

Hossack BR Pilliod DS (2011) Amphibian responses to wildfire in the western United States: Emerging patterns from short-term studies. Fire Ecol 7:129-144. https://doi.org/10.4996/fireecology.0702129

Jolly WM, Cochrane MA, Freeborn PH, Holden ZA, Brown TJ, Williamson GJ, Bowman DM (2015) Climate-induced variations in global wildfire danger from 1979 to 2013. Nat Commun 6:1-11. https://doi.org/10.1038/ncomms8537

Keeler BL, Polasky S, Brauman KA, Johnson KA, Finlay JC, O’Neill A, Kovacs K et al (2012) Linking water quality and well-being for improved assessment and valuation of ecosystem services. Proceedings of the National Academy of Sciences 109: 18619-18624. https://doi.org/10.1073/pnas.1215991109

Kelly LT, Giljohann KM, Duane A, Aquilué N, Archibald S, Batllori E, Bennett AF et al (2020) Fire and biodiversity in the Anthropocene. Science 370:eabb0355. https://doi.org/10.1126/science.abb0355

Larson DM (2014) Grassland fire and cattle grazing regulate reptile and amphibian assembly among patches. Environmental Management 54:1434-1444. https://doi.org/10.1007/s00267-014-0355-2

Lathrop Jr, RG (1994) Impacts of the 1988 wildfires on the water quality of Yellowstone and Lewis Lakes, Wyoming. International Journal of Wildland Fire 4:169-175. https://doi.org/10.1071/WF9940169

Leal Filho, Totin E, Franke JA, Andrew SM, Abubakar IR, Azadi H, Nunn PD et al (2022) Understanding responses to climate-related water scarcity in Africa. Sci Total Environ 806:150420. https://doi.org/10.1016/j.scitotenv.2021.150420

Loiselle D, Du X, Alessi DS, Bladon KD, Faramarzi M (2020) Projecting impacts of wildfire and climate change on streamflow, sediment, and organic carbon yields in a forested watershed. J Hydrol 590:125403. https://doi.org/10.1016/j.jhydrol.2020.125403

Lovich JE, Quillman M, Zitt B, Schroeder A, Green DE, Yackulic C, Gibbons P et al (2017) The effects of drought and fire in the extirpation of an abundant semi-aquatic turtle from a lacustrine environment in the southwestern USA. Knowl Manag Aquat Ecosyst 418:1-11. https://doi.org/10.1051/kmae/2017008

McCullough IM, Cheruvelil KS, Lapierre JF, Lottig NR, Moritz MA, Stachelek J, Soranno PA (2019) Do lakes feel the burn? Ecological consequences of increasing exposure of lakes to fire in the continental United States. Global Change Biol 25:2841-2854. https://doi.org/10.1111/gcb.14732

Migiro G (2018) European countries with the most forest fires. WorldAtlas. https://www.worldatlas.com/articles/european-countries-with-the-most-forest-fires.html. Accessed 15 December 2021

Misachi J (2018) Which country has the most fresh water? WorldAtlas. https://www.worldatlas.com/articles/countries-with-the-most-freshwater-resources.html. Accessed 23 December 2021

Monaghan KA, Machado AL, Corado M, Wrona FJ, Soares AM (2019) Seasonal time-series reveal the impact and rapid recovery in richness, abundance and community structure of benthic macroinvertebrates following catchment wildfire. Sci Total Environ 651:3117-3126. https://doi.org/10.1016/j.scitotenv.2018.10.176

Monaghan KA, Machado AL, Wrona FJ, Soares AM (2016) The impact of wildfire on stream fishes in an Atlantic-Mediterranean climate: evidence from an 18-year chronosequence. Knowledge and Management of Aquatic Ecosystems 417:1-11. https://doi.org/10.1051/kmae/2016015

Muñoz A, Felicísimo ÁM, Santos X (2019) Assessing the resistance of a breeding amphibian community to a large wildfire. Acta Oecol 99:103439. https://doi.org/10.1016/j.actao.2019.06.002

Naylor BJ, Mackereth RW, Kreutzweiser DP, Sibley PK (2012) Merging END concepts with protection of fish habitat and water quality in new direction for riparian forests in Ontario: a case study of science guiding policy and practice. Freshw Sci 31:248-257.

Nieder R, Benbi DK, Reichi FX (2018) Reactive water-soluble forms of nitrogen and phosphorus and their impacts on environment and human health. In: Nieder R, Benbi DK, Reichl FX (eds) Soil components and human health. Springer, Dordrecht, pp 223-225

Nuñez MA, Chiuffo MC, Pauchard A, Zenni RD (2021) Making ecology really global. Trends Ecol Evol 36:766-769. https://doi.org/10.1016/j.tree.2021.06.004

Oliver AA, Bogan MT, Herbst DB, Dahlgren RA (2012) Short-term changes in-stream macroinvertebrate communities following a severe fire in the Lake Tahoe basin, California. Hydrobiologia 694:117-130. https://doi.org/10.1007/s10750-012-1136-7

Omer NH (2019) Water quality parameters. In: Summers JK (ed) Water quality: science, assessments and policy. IntechOpen, London, pp 3⎼19.

Pastro LA, Dickman CR, Letnic M (2014) Fire type and hemisphere determine the effects of fire on the alpha and beta diversity of vertebrates: a global meta-analysis. Global Ecol Biogeog 23:1146-1156. https://doi.org/10.1111/geb.12195

Pausas JG, Keeley JE (2009) A burning story: the role of fire in the history of life. BioScience 59:593-601. https://doi.org/10.1525/bio.2009.59.7.10

Pausas JG, Ribeiro E (2017) Fire and plant diversity at the global scale. Global Ecol Biogeog 26:889-897. https://doi.org/10.1111/geb.12596

Pennino MJ, Leibowitz SG, Compton JE, Beyene MT, LeDuc SD (2022) Wildfires can increase regulated nitrate, arsenic, and disinfection byproduct violations and concentrations in public drinking water supplies. Sci Total Environ 804: 149890. https://doi.org/10.1016/j.scitotenv.2021.149890

Pereira P, Úbeda X, Francos M (2019) Laboratory fire simulations: plant litter and soils. In: Pereira P, Mataix-Solera J, Úbeda X, Rein G, Cerdà A (eds) Fire effects on soil properties. CSIRO Publishing, Clayton South, pp 15-38.

Pettit NE, Naiman RJ (2007) Fire in the riparian zone: Characteristics and ecological consequences. Ecosystems 10:673-687. https://doi.org/10.1007/s10021-007-9048-5

Pilliod DS, Bury RB, Hyde EJ, Pearl CA, Corn PS (2003) Fire and amphibians in North America. For Ecol Manag 178:163-181. https://doi.org/10.1016/s0378-1127(03)00060-4

Pradhan A, Carvalho F, Abrantes N, Campos I, Keizer JJ, Cássio F, Pascoal C (2020) Biochemical and functional responses of stream invertebrate shredders to post-wildfire contamination. Environ Poll 267:115433. https://doi.org/10.1016/j.envpol.2020.115433

Pullin AS, Stewart GB (2006) Guidelines for systematic review in conservation and environmental management. Conserv Biol 20:1647-1656. https://doi.org/10.1111/j.1523-1739.2006.00485.x

R Development Core Team (2020) R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. https://www.R-project.org/

Reid AJ, Carlson AK, Creed IF, Eliason EJ, Gell PA, Johnson PT, Kidd KA et al (2019) Emerging threats and persistent conservation challenges for freshwater biodiversity. Biol Rev 94:849-873. https://doi.org/10.1111/brv.12480

Rhea AE, Covino TP, Rhoades CC (2021) Reduced N‐limitation and increased in‐stream productivity of autotrophic biofilms 5 and 15 years after severe wildfire. Journal of Geophysical Research: Biogeosciences 126:e2020JG006095. https://doi.org/10.1029/2020jg006095

Robinne FN, Bladon KD, Miller C, Parisien MA, Mathieu J, Flannigan MD (2018) A spatial evaluation of global wildfire-water risks to human and natural systems. Sci Total Environ 610-611:1193-1206. https://doi.org/10.1016/j.scitotenv.2017.08.112

Robinne FN, Hallema DW, Bladon KD, Flannigan MD, Boisramé G, Bréthaut CM, Doerr SH et al (2021) Scientists' warning on extreme wildfire risks to water supply. Hydrol Process 35:1-11. https://doi.org/10.1002/hyp.14086

Rugenski AT, Minshall GW (2014) Climate-moderated responses to wildfire by macroinvertebrates and basal food resources in montane wilderness streams. Ecosphere 5:1Hydrological Processes24. https://doi.org/10.1890/ES13-00236.1

Rust AJ, Randell J, Todd AS, Hogue TS (2019) Wildfire impacts on water quality, macroinvertebrate, and trout populations in the Upper Rio Grande. For Ecol Manag 453:117636. https://doi.org/10.1016/j.foreco.2019.117636

Santín C, Doerr SH (2016) Fire effects on soils: the human dimension. Philos Trans R Soc B: Biol Sci 371:20150171. https://doi.org/10.1098/rstb.2015.0171

Shakesby RA, Doerr SH (2006) Wildfire as a hydrological and geomorphological agent. Earth-Sci Rev 74:269-307. https://doi.org/10.1016/j.earscirev.2005.10.006

Shiklomanov IA (1993) World fresh water resources. In: Gleik PH (ed) Water in crisis: a guide to the world’s fresh water resources. Oxford University Press, New York, pp 13-24.

Silva LG, Doyle KE, Duffy D, Humphries P, Horta A, Baumgartner LJ (2020) Mortality events resulting from Australia's catastrophic fires threaten aquatic biota. Global Change Biol 26:5345-5350. https://doi.org/10.1111/gcb.15282

Silva V, Abrantes N, Costa R, Keizer JJ, Goncalves F, Pereira JL (2016) Effects of ash-loaded post-fire runoff on the freshwater clam Corbicula fluminea. Ecol Eng 90:180-189. https://doi.org/10.1016/j.ecoleng.2016.01.043

Silva V, Pereira JL, Campos I, Keizer JJ, Gonçalves F, Abrantes N (2015) Toxicity assessment of aqueous extracts of ash from forest fires. Catena 135:401-408. https://doi.org/10.1016/j.catena.2014.06.021

Smith HG, Sheridan GJ, Lane PN, Nyman P, Haydon S (2011) Wildfire effects on water quality in forest catchments: A review with implications for water supply. J Hydrol 396:170-192. https://doi.org/10.1016/j.jhydrol.2010.10.043

Sundarambal P, Balasubramanian R, Tkalich P, He J (2010) Impact of biomass burning on ocean water quality in Southeast Asia through atmospheric deposition: field observations. Atmos Chem Phys 10:11323-11336.

Teixido AL, Sehn H, Quintanilla LG, Gonçalves SR, Fernández‐Arellano GJ, Dáttilo W, Izzo TJ et al (2021) A meta‐analysis of the effects of fragmentation on the megadiverse herpetofauna of Brazil. Biotropica 53:726-737. https://doi.org/10.1111/btp.12955

Townsend SA, Douglas M (2004) The effect of a wildfire on stream water quality and catchment water yield in a tropical savanna excluded from fire for 10 years (Kakadu National Park, North Australia). Water Res 38:3051-3058. https://doi.org/10.1016/j.watres.2004.04.009

UN General Assembly (2015) Transforming our world: the 2030 Agenda for sustainable development, 21 October 2015, A/RES/70/1. https://www.refworld.org/docid/57b6e3e44.html. Accessed 22 December 2021

USGS (2013) Where is Earth’s water? United States Geological Survey. United States Department of the Interior. http://ga.water.usgs.gov/edu/earthwherewater.html. Accessed 17 december 2021

Vasconcelos HL, Maravalhas JB, Cornelissen T (2017) Effects of fire disturbance on ant abundance and diversity: a global meta-analysis. Biodivers Conserv 26:177-188. https://doi.org/10.1007/s10531-016-1234-3

Veach AM, Troia MJ, Cregger MA (2021) Assessing biogeographic survey gaps in bacterial diversity knowledge: A global synthesis of freshwaters. Fresh Biol 66:1595-1605. https://doi.org/10.1111/fwb.13777

Venne LS, Frederick PC (2013) Foraging wading bird (Ciconiiformes) attraction to prescribed burns in an oligotrophic wetland. Fire Ecol 9:78-95. https://doi.org/10.4996/fireecology.0901078

Vörösmarty CJ, McIntyre PB, Gessner MO, Dudgeon D, Prusevich A, Green P, Glidden S et al (2010) Global threats to human water security and river biodiversity. Nature 467:555-561. https://doi.org/10.1038/nature09440

Vukomanovic J, Steelman T (2019) A systematic review of relationships between mountain wildfire and ecosystem services. Landsc Ecol 34:1179-1194. https://doi.org/10.1007/s10980-019-00832-9

Wan S, Hui D, Luo Y (2001) Fire effects on nitrogen pools and dynamics in terrestrial ecosystems: a meta-analisis. Ecol Appl 11:1349-1365. https://doi.org/10.1890/1051-0761(2001)011[1349:feonpa]2.0.co;2

Wurtsbaugh WA, Heredia NA, Laub BG, Meredith CS. Mohn HE, Null SE, Pluth DA et al (2015) Approaches for studying fish production: Do river and lake researchers have different perspectives? Can J Fish Aquat 72:149-160. https://doi.org/10.1139/cjfas-2014-0210

Wyk PT, Scarpa J (1999) Water quality requirements and management. In: Wyk PT, Davis-Hodgkins M, Laramore R, Main KL, Mountain J, Scarpa J (eds) Farming marine shrimp in recirculating freshwater systems. Florida Department of Agriculture and Consumer Services, St. Lucie, pp 141-161.

Xu M, Wang Z, Duan X, Pan B (2014) Effects of pollution on macroinvertebrates and water quality bio-assessment. Hydrobiologia 729:247-259. https://doi.org/10.1007/s10750-013-1504-y

Yu P, Xu R, Abramson MJ, Li S, Guo Y (2020) Bushfires in Australia: a serious health emergency under climate change. Lancet Planet Health 4:e7-e8. https://doi.org/10.1016/s2542-5196(19)30267-0

Table 1. Set of all the analysed chemical and physical water quality parameters and number of cases reported for altered (i.e., increase or decrease) or unaltered (i.e., neutral) responses to fire of these parameters across the 54 publications included in this review. Numbers in brackets indicate the percentage of cases over the total number of cases reported for each parameter.

Water quality parameters	Type of water quality parameters	Response
		Altered		Unaltered
		Increase	Decrease	Unaltered
Acid neutralising capacity (mEq/L)	Chemical	-	1(100)	-
AI - Autotrophic Index (g/m²)	Chemical	1(100)	-	-
Alkalinity (mg CaCO₃/L)	Chemical	5(71.4)	1(14.3)	1(14.3)
Aluminium (Al3+) (mg/L)	Chemical	4(80.0)	1(20.0)	-
Ammonium (NH₄+) (mg/L)	Chemical	7(41.2)	4(23.5)	6(35.3)
Antimony (Sb3+) (mg/L)	Chemical	1(100)	-	-
Arsenic (AsH₃O₄) (mg/L)	Chemical	1(50.0)	-	1(50.0)
Benthic organic matter (g/m²)	Chemical	2(100)	-	-
Bicarbonate (HCO₃) (mg/L)	Chemical	1(33.3)	1(33.3)	1(33.3)
Bromine (Br₋) (mg/L)	Chemical	-	1(50)	1(50)
Calcium (Ca2+) (mg/L)	Chemical	7(43.8)	2(12.4)	7(43.8)
Chlorine (Cl₋) (mg/L)	Chemical	3(33.3)	2(22.2)	4(44.5)
Chromium (Cr3+) (mg/L)	Chemical	1(100)	-	-
Copper (Cu2+) (mg/L)	Chemical	1(50.0)	-	1(50.0)
Dissolved black carbon (mg C/L)	Chemical	1(100)	-	-
Dissolved inorganic carbon (ppm)	Chemical	1(100)	-	-
Dissolved organic carbon (ppm)	Chemical	7(53.8)	2(15.4)	4(30.8)
Dissolved organic phosphorus (mg/L)	Chemical	-	-	1(100)
Dissolved oxygen (mg/L)	Chemical	1(10.0)	7(70.0)	2(20.0)
Dissolved silica (SiO₂) (mg/L)	Chemical	-	1(33.3)	2(66.7)
Filterable reactive phosphate (mg/L)	Chemical	2(100)	-	-
Fine particulate organic matter (mg/L)	Chemical	1(100)	-	-
Fluorine (F₋) (mg/L)	Chemical	-	-	2(100)
Hardness (mg CaCO₃/L)	Chemical	1(25.0)	1(25.0)	2(50.0)
Heavy metals (mg/L)	Chemical	-	-	1(100)
Iron (Fe2+) (mg/L)	Chemical	4(57.1)	1(14.3)	2(28.6)
Lead (Pb2+) (mg/L)	Chemical	1(100)	-	-
Lithium (Li+) (mg/L)	Chemical	1(100)	-	-
Magnesium (Mg2+) (mg/L)	Chemical	9(56.2)	-	7(43.8)
Major ions (mg/L)	Chemical	1(100)	-	-
Manganese (Mn2+) (mg/L)	Chemical	2(66.7)	-	1(33.3)
Mercury (Hg2+) (mg/L)	Chemical	-	-	1(100)
Nickel (Ni2+) (mg/L)	Chemical	-	-	1(100)
Nitrate (NO₃₋) (mg/L)	Chemical	16(57.1)	3(10.7)	9(32.2)
Orthophosphate (mg/L)	Chemical	2(66.7)	-	1(33.3)
Oxidized nitrogen (NO) (mg/L)	Chemical	-	-	1(100)
Particulate black carbon (mg C/L)	Chemical	1(100)	-	-
pH (H+)	Chemical	6(35.3)	3(17.6)	8(47.1)
Phenols (C₆H₅OH) (mg/L)	Chemical	1(100)	-	-
Phosphate (PO₄3₋) (mg/L)	Chemical	2(25.0)	1(12.5)	5(62.5)
Polycyclic aromatic hydrocarbons (ng/L)	Chemical	3(100)	-	-
Potassium (K+) (mg/L)	Chemical	8(53.3)	-	7(46.7)
Selenium (Se) (mg/L)	Chemical	1(100)	-	-
Silver (Ag+) (mg/L)	Chemical	-	-	1(100)
Sodium (Na+) (mg/L)	Chemical	4(26.7)	3(20.0)	8(53.3)
Soluble reactive phosphorus (mg/L)	Chemical	3(100)	-	-
Sulphur (S2₋) (mg/L)	Chemical	2(100)	-	-
Sulphate (SO₄2₋) (mg/L)	Chemical	3(30.0)	2(20.0)	5(50.0)
Suspended organic carbon (mg/L)	Chemical	1(100)	-	-
Thick particulate organic matter (mg/L)	Chemical	1(100)	-	-
Titanium (Ti4+) (mg/L)	Chemical	1(100)	-	-
Total inorganic solutes (mg/L)	Chemical	1(100)	-	-
Total Kjeldahl nitrogen (mg/L)	Chemical	2(66.7)	-	1(33.3)
Total nitrogen (mg/L)	Chemical	16(69.6)	4(17.4)	3(13.0)
Total phosphorus (mg/L)	Chemical	16(66.7)	2(8.3)	6(25.0)
Vanadium (V2+) (mg/L)	Chemical	1(100)	-	-
Zinc (Zn2+) (mg/L)	Chemical	1(100)	-	-
Depth (m)	Physical	-	1(100)	-
Electric conductivity (μs/cm)	Physical	14(73.7)	-	5(26.3)
Light attenuation coefficient (εPAR)	Physical	1(100)	-	-
Refractory black carbon nanoparticles (μg/L)	Physical	-	-	1(100)
Secchi transparency (cm)	Physical	-	1(100)	-
Sediment concentration (mg/L)	Physical	4(100)	-	-
Sedimentation rate (kg/s)	Physical	1(100)	-	-
Specific conductance (µS/cm)	Physical	-	-	1(100)
Streamflow (m³/s)	Physical	2(100)	-	-
Substrate diameter (cm)	Physical	-	1(100)	-
Temperature (°C)	Physical	8(72.7)	-	3(27.3)
Thick inorganic sediment (mg/L)	Physical	-	-	1(100)
Total dissolved solids (mg/L)	Physical	3(75.0)	-	1(25.0)
Total suspended solids (mg/L)	Physical	9(81.8)	-	2(18.2)
Turbidity (NTU)	Physical	12(80.0)	-	3(20.0)
Ultraviolet absorbance (SUVA254) (L/mg-m)	Physical	-	-	1(100)
Volatile suspended sediments (mg/L)	Physical	1(50.0)	-	1(50.0)
Total	-	213(55.9%)	46(12.1%)	122(32.0%)

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Fire and water: global fire impacts on physicochemical properties of freshwater ecosystems

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