Lluís Gómez-GenerCREAF Centre for Ecological Research and Forestry Applications | CREAF · Department of Ecology
Lluís Gómez-Gener
Ph.D. in Ecology - M.Sc. in Water Sciences - Degree in Environmental Chemistry
About
41
Publications
20,560
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1,129
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Citations since 2017
Introduction
My research focuses on understanding how carbon (C) moves and cycle across different scales in catchments. This integrates:
1) the identification of regimes for different C species (e.g., CO2, DIC, or DOC) in river networks;
2) the study of processes at ecohydrological interfaces (e.g., land-water, or water-atmosphere);
3) the evaluation of changes in watershed C dynamics as a consequence of human- and climate-driven hydrological changes (e.g., droughts, snowmelt changes or glacier retreat)
Additional affiliations
January 2019 - present
June 2017 - December 2018
November 2012 - February 2017
Publications
Publications (41)
A longstanding challenge in stream ecology is to understand how landscape configuration organizes spatial patterns of ecosystem function via lateral groundwater connections. We combined laboratory bioassays and field additions of a metabolic tracer (resazurin) to test how groundwater‐stream confluences, or “discrete riparian inflow points” (DRIPs),...
River networks represent the largest biogeochemical nexus between the continents, ocean and atmosphere. Our current understanding of the role of rivers in the global carbon cycle remains limited, which makes it difficult to predict how global change may alter the timing and spatial distribution of riverine carbon sequestration and greenhouse gas em...
Hypoxia in coastal waters and lakes is widely recognized as a detrimental environmental issue, yet we lack a comparable understanding of hypoxia in rivers. We investigated controls on hypoxia using 118 million paired observations of dissolved oxygen (DO) concentration and water temperature in over 125,000 locations in rivers from 93 countries. We f...
The flux of terrestrial carbon across land‐water boundaries influences the overall carbon balance of landscapes and the ecology and biogeochemistry of aquatic ecosystems. The local consequences and broader fate of carbon delivered to streams is determined by the overall composition of carbon inputs, including the balance of organic and inorganic fo...
• Primary production is a fundamental ecosystem process that influences nutrient and carbon cycling, and trophic structure in streams. The magnitude and timing of gross primary production (GPP) are typically controlled by hydrology, light, nutrient availability and grazers. Estimates of GPP and its drivers in high-mountain streams remain elusive at...
Surface-groundwater interactions in intermittent rivers and ephemeral streams (IRES), waterways which do not flow year-round, are spatially and temporally dynamic because of alternations between flowing, non-flowing and dry hydrological states. Interactions between surface and groundwater often create mixing zones with distinct redox gradients, pot...
Carbon dioxide (CO2) emissions to the atmosphere from running waters are estimated to be four times greater than the total carbon (C) flux to the oceans. However, these fluxes remain poorly constrained because of substantial spatial and temporal variability in dissolved CO2 concentrations. Using a global compilation of high-frequency CO2 measuremen...
High‐resolution time series of dissolved oxygen (DO) have revealed different ecosystem energetics regimes across various stream types. Ecosystem energetic regimes are relevant to better understand the transformation and retention of nutrients and carbon in stream ecosystems. However, the patterns and controls of stream energetics in high‐mountain l...
The seasonality of gross primary production (GPP) in streams is driven by multiple physical and chemical factors , yet incident light is often thought to be most important. In Arctic tundra streams, however, light is available in saturating amounts throughout the summer, but sharp declines in nutrient supply during the terrestrial growing season ma...
The origin and reactivity of dissolved organic matter (DOM) have received attention for decades due to the key role DOM plays in global carbon cycling and the ecology of aquatic systems. However, DOM dynamics in river networks remain unresolved, hampered by the lack of data integrating the spatial and temporal dimensions inherent to riverine ecosys...
Many inland waters exhibit complete or partial desiccation, or have vanished due to global change, exposing sediments to the atmosphere. Yet, data on carbon dioxide (CO 2) emissions from these sediments are too scarce to upscale emissions for global estimates or to understand their fundamental drivers. Here, we present the results of a global surve...
Drought is a global phenomenon, with widespread implications for freshwater ecosystems. While droughts receive much attention at lower latitudes, their effects on northern river networks remain unstudied. We combine a reach-scale manipulation experiment, observations during the extreme 2018 drought, and historical monitoring data to examine the imp...
Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and...
Carbon dioxide (CO 2 ) evasion from streams greatly contributes to global carbon fluxes. Despite this, the temporal dynamics of CO 2 and its drivers remain poorly understood to date. This is particularly true for high-altitude streams. Using high-resolution time series of CO 2 concentration and specific discharge from sensors in twelve streams in t...
Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of...
Coordinated distributed experiments (CDEs) allow the study of large-scale ecological patterns in geographically dispersed areas, providing at the same time broad benefits for the participants. However, the effective involvement of early-stage career researchers (ECRs) confronts major challenges. Here, we analyze the benefits and challenges of the f...
Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and peri...
A large part of the world's inland waters, including streams, rivers, ponds, lakes and reservoirs is subject to occasional, recurrent or even permanent drying. Moreover, the occurrence and intensity of drying events are increasing in many areas of the world because of climate change, water abstraction, and land use alteration. Yet, information on t...
The impoundment of running waters through the construction of large dams is recognised as one of the most important factors determining the transport, transformation, and outgassing of carbon (C) in fluvial networks. However, the effects of small and very small water retention structures (SWRS) on the magnitude and spatiotemporal patterns of C emis...
Large variability in dissolved organic carbon (DOC) uptake rates has been reported for headwater streams, but the causes of this variability are still not well understood. Here we assessed acetate uptake rates across 11 European streams comprising different ecoregions by using whole-reach pulse acetate additions. We evaluated the main climatic and...
Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES),which sometimes cease to flow and can dry completely, is largely ignored although theymay represent over half the global river network. Substantial amounts of terrestrialplant...
Stream water quality and greenhouse gas production are both influenced by the metabolic activity of stream ecosystems. Understanding the temporal and spatial variability of metabolism is paramount for the implementation of effective mitigation measures aimed to improve stream water quality. We analysed the influence of various stream segments on th...
Global change is dramatically altering flow regimes worldwide. Among the most important consequences are the transition of many permanent waterways to temporary waterways, the increase in duration and frequency of non-flow periods of temporary streams, and the increase in the severity (i.e. irradiance, temperature and humidity) of the non-flow peri...
Despite the increasing understanding of the magnitude and drivers of carbon gas emissions from inland waters, the relevance of water fluctuation and associated drying on their dynamics is rarely addressed. Here, we quantified CO 2 and CH 4 fluxes from a set of temporary ponds across seasons. The ponds were in all occasion net CO 2 emitters irrespec...
Streams play a key role in the global biogeochemical cycles, processing material from adjacent terrestrial systems and transporting it downstream. However, the drivers of stream metabolism, especially those acting at broad spatial scales, are still not well understood. Moreover, stream metabolism can be affected by hydrological changes associated w...
Many lakes exhibit seasonal stratification, during which they develop strong thermal and chemical gradients. An expansion of depth-integrated monitoring programs has provided insight into the importance of organic carbon processing that occurs below the upper mixed layer. However, the chemical and physical drivers of metabolism and metabolic coupli...
Inland waters are active components of the global carbon (C) cycle that transform, store and outgas more than half of the C they receive from adjacent terrestrial ecosystems. In particular, C emissions from fluvial networks to the atmosphere represent a substantial flux in the global C cycle. However, fundamental uncertainties regarding the spatiot...
The potential for rivers to alter the flux of dissolved organic matter (DOM) from land to ocean is widely accepted. Yet anticipating when and where rivers behave as active reactors vs. passive pipes of DOM stands as a major knowledge gap in river biogeochemistry, resulting in uncertainties for global carbon models. Here, we investigate the controls...
Inland waters are significant sources of carbon dioxide (CO2) to the atmosphere. CO2 supersaturation and subsequent CO2 emissions from inland waters can be driven by internal metabolism, external inputs of dissolved inorganic carbon (DIC) derived from the catchment and other processes (e.g., internal geochemical reactions of calcite precipitation o...
![Figure 5. Mean (+1 SD, n = 6 [3/season]) combined spring and summer...](profile/Lorenzo-Proia/publication/308818453/figure/fig5/AS:667912549457922@1536254169143/Mean-1-SD-n-6-3-season-combined-spring-and-summer-total-community-benthic_Q320.jpg)
The hydrological continuum in rivers can be altered by the presence of small dams that modify the water residence time (WRT) and prevailing habitat, turning lotic river sections into lentic ones and influencing downstream reaches. The structure and activity of the microbial community occurring in the benthic and planktonic compartments can be modif...
Most fluvial networks worldwide include watercourses that recurrently cease to flow and run dry. The spatial and temporal extent of the dry phase of these temporary watercourses is increasing as a result of global change. Yet, current estimates of carbon emissions from fluvial networks do not consider temporary watercourses when they are dry. We ch...
The composition of dissolved organic matter (DOM) in rivers results from the different sources and in-stream transformations along the land to ocean aquatic continuum. Riverine DOM sources are highly dependent on the hydrological connection between the river channel and the surrounding terrestrial ecosystems, but how the lack of this connectivity (...
During summer drought, Mediterranean fluvial networks are transformed into highly heterogeneous landscapes characterized by different environments (i.e., running and impounded waters, isolated river pools and dry beds). This hydrological setting defines novel biogeochemically active areas that could potentially increase the rates of carbon emission...
Mediterranean rivers are extensively modified by flow regulation practises along their courses. An important part of the river impoundment in this area is related to the presence of small dams constructed mainly for water abstraction purposes. These projects drastically modified the ecosystem morphology, transforming lotic into lentic reaches and i...
Carbon dioxide efflux during the flooding phase of temporary ponds Small water bodies, such as temporary ponds, have a high carbon processing potential. Nevertheless, despite the global occurrence of these systems, the carbon effluxes from such water bodies have been largely overlooked. In this study, we examined the intra-and intersystem variabili...
Temporary watercourses that naturally cease to flow and run dry comprise a notable fraction of the world’s river
networks, yet estimates of global carbon dioxide (CO2) emissions from watercourses do not consider emissions from these systems when they are dry. Using data from a sampling campaign in a Mediterranean river during the summer drought per...
Projects
Projects (7)
The overarching goal of this project is to develop a new framework (integrating terrestrial-aquatic as well gradual-intermittent transitions) for understanding C transport dynamics in high-mountain headwaters and to confront ongoing debate on their significance to the broader C cycle.
The overall aim of this project is to elucidate the biogeochemical processes that control the pH-alkalinity variation at fine scales in mountain aquatic sistems (e.g. microhabitats, interannual and decadal tendencies and fluctuations, changes across vegetation gradients), providing the reference to characterize the fluctuations that local diatoms communities may experience. T
Streams and rivers are important players in the global carbon cycle. Whole-ecosystem gross primary production and respiration as key components of the carbon cycle in streams have received considerable attention over the last decades. However, biogeochemistry and ecosystem science have failed to appreciate and understand the metabolic regimes of streams. METALP will combine next-generation wireless sensor networks with state-of-the-art drone technology to monitor metabolism and CO2 dynamics in a stream network in the Swiss Alps. Data will be cast into an ecohydraulic framework, based of first principles from hydrology and geomorphology, to mechanistically explain and predict the metabolic regime of Alpine streams and ultimately of the networks they form. METALP will also assess the contribution of ecosystem respiration to CO2 evasion fluxes from streams to the atmosphere. Thereby, it will shed light on a major and ongoing debate on the source of CO2 outgassing from streams to the atmosphere. Establishing this link is fundamental to pinpoint the role of streams in the global carbon cycle. Findings from METALP will lay the foundation to explore nearby metabolic regime shifts and to use streams as sentinels for environmental change. Such an advancement of stream ecosystem science may be particularly relevant in the European Alps where climate change and local human pressures alter ecosystems at rapid pace.
