Paul Moorcroft - Academia.edu (original) (raw)

Papers by Paul Moorcroft

Research paper thumbnail of The changing carbon balance of tundra ecosystems: results from a vertically-resolved peatland biosphere model

Environmental Research Letters, Dec 30, 2021

An estimated 1700 Pg of carbon is frozen in the Arctic permafrost and the fate of this carbon is ... more An estimated 1700 Pg of carbon is frozen in the Arctic permafrost and the fate of this carbon is unclear because of the complex interaction of biophysical, ecological and biogeochemical processes that govern the Arctic carbon budget. Two key processes determining the region’s long-term carbon budget are: (a) carbon uptake through increased plant growth, and (b) carbon release through increased heterotrophic respiration (HR) due to warmer soils. Previous predictions for how these two opposing carbon fluxes may change in the future have varied greatly, indicating that improved understanding of these processes and their feedbacks is critical for advancing our predictive ability for the fate of Arctic peatlands. In this study, we implement and analyze a vertically-resolved model of peatland soil carbon into a cohort-based terrestrial biosphere model to improve our understanding of how on-going changes in climate are altering the Arctic carbon budget. A key feature of the formulation is that accumulation of peat within the soil column modifies its texture, hydraulic conductivity, and thermal conductivity, which, in turn influences resulting rates of HR within the soil column. Analysis of the model at three eddy covariance tower sites in the Alaskan tundra shows that the vertically-resolved soil column formulation accurately captures the zero-curtain phenomenon, in which the temperature of soil layers remain at or near 0 °C during fall freezeback due to the release of latent heat, is critical to capturing observed patterns of wintertime respiration. We find that significant declines in net ecosystem productivity (NEP) occur starting in 2013 and that these declines are driven by increased HR arising from increased precipitation and warming. Sensitivity analyses indicate that the cumulative NEP over the decade responds strongly to the estimated soil carbon stock and more weakly to vegetation abundance at the beginning of the simulation.

Research paper thumbnail of Erratum: Monitoring plant functional diversity from space

Nature plants, Mar 14, 2016

Research paper thumbnail of Ecosystem Demography Model, version 2.2 (ED-2.2)

This version contains all the model developments for ED-2.2 and described in Longo et al. (2019) ... more This version contains all the model developments for ED-2.2 and described in Longo et al. (2019) (https://dx.doi.org/10.5194/gmd-2019-45).

Research paper thumbnail of Ecological and Behavioral Drivers of Supplemental Feeding Use by Roe Deer Capreolus capreolus in a Peri-Urban Context

Animals, 2020

Winter supplemental feeding of ungulates potentially alters their use of resources and ecological... more Winter supplemental feeding of ungulates potentially alters their use of resources and ecological interactions, yet relatively little is known about the patterns of feeding sites use by target populations. We used camera traps to continuously monitor winter and spring feeding site use in a roe deer population living in a peri-urban area in Northern Italy. We combined circular statistics with generalized additive and linear mixed models to analyze the diel and seasonal pattern of roe deer visits to feeding sites, and the behavioral drivers influencing visit duration. Roe deer visits peaked at dawn and dusk, and decreased from winter to spring when vegetation regrows and temperature increases. Roe deer mostly visited feeding sites solitarily; when this was not the case, they stayed longer at the site, especially when conspecifics were eating, but maintained a bimodal diel pattern of visits. These results support an opportunistic use of feeding sites, following seasonal cycles and the ...

Research paper thumbnail of The impacts of Amazon forest degradation and fragmentation on energy, water, and carbon cycles

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Research paper thumbnail of Cluster-based trajectory segmentation with local noise

Data Mining and Knowledge Discovery, 2018

We present a framework for the partitioning of a spatial trajectory in a sequence of segments bas... more We present a framework for the partitioning of a spatial trajectory in a sequence of segments based on spatial density and temporal criteria. The result is a set of temporally separated clusters interleaved by sub-sequences of unclustered points. A major novelty is the proposal of an outlier or noise model based on the distinction between intra-cluster (local noise) and inter-cluster noise (transition): the local noise models the temporary absence from a residence while the transition the definitive departure towards a next residence. We analyze in detail the properties of the model and present a comprehensive solution for the extraction of temporally ordered clusters. The effectiveness of the solution is evaluated first qualitatively and next quantitatively by contrasting the segmentation with ground truth. The ground truth consists of a set of trajectories of labeled points simulating animal movement. Moreover, we show that the approach can streamline the discovery of additional derived patterns, by presenting a novel technique for the analysis of periodic movement. From a methodological perspective, a valuable aspect of this research is that it combines the theoretical investigation with the application and external validation of the segmentation framework. This paves the way to an effective deployment of the solution in broad and challenging fields such as e-science.

Research paper thumbnail of How close are we to a predictive science of the biosphere?

Trends in Ecology & Evolution, 2006

In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipli... more In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipline to a central area of modern climate change research. The development of terrestrial biosphere models that predict the responses of ecosystems to climate and increasing CO 2 levels has highlighted several mechanisms by which changes in ecosystem composition and function might alter regional and global climate. However, results from empirical studies suggest that ecosystem responses can differ markedly from the predictions of terrestrial biosphere models. As I discuss here, the challenge now is to connect terrestrial biosphere models to empirical ecosystem measurements. Only by systematically evaluating the predictions of terrestrial biosphere models against suites of ecosystem observations and experiments measurements will a true predictive science of the biosphere be achieved.

Research paper thumbnail of Building the bridge between animal movement and population dynamics

Philosophical Transactions of the Royal Society B: Biological Sciences, 2010

While the mechanistic links between animal movement and population dynamics are ecologically obvi... more While the mechanistic links between animal movement and population dynamics are ecologically obvious, it is much less clear when knowledge of animal movement is a prerequisite for understanding and predicting population dynamics. GPS and other technologies enable detailed tracking of animal location concurrently with acquisition of landscape data and information on individual physiology. These tools can be used to refine our understanding of the mechanistic links between behaviour and individual condition through ‘spatially informed’ movement models where time allocation to different behaviours affects individual survival and reproduction. For some species, socially informed models that address the movements and average fitness of differently sized groups and how they are affected by fission–fusion processes at relevant temporal scales are required. Furthermore, as most animals revisit some places and avoid others based on their previous experiences, we foresee the incorporation of ...

Research paper thumbnail of Evaluation Of The Ecosystem Demography Model Version 2 (ED2) In North America

Research paper thumbnail of High temperature sensitivity of peat decomposition due to physical-biogeochemical feedback

Research paper thumbnail of Southeast Asian peatland drainage emits 220 Mt of carbon per year, equivalent to 2.2% of global fossil-fuel emissions

Southeast Asian peatlands are climatically important ecosystems, storing approximately 70 billion... more Southeast Asian peatlands are climatically important ecosystems, storing approximately 70 billion tons of carbon. Natural and human-induced droughts are lowering peatland water tables, increasing decomposition and the risk of peat-burning wildfires. The rapid nature of carbon losses arising from peatland drainage and accompanying fire-related losses compared to the slow accumulation of peat means that the effects of peatland drainage are essentially irreversible on human timescales. Here, we use a terrestrial biosphere model incorporating vertically-resolved peatland carbon and water dynamics to predict decomposition and fire in Southeast Asia as a result drainage-induced drying. The model captures observed patterns of interannual and seasonal variation in soil moisture and its soil moisture estimates are a better predictor of observed burned area fraction than either precipitation or remotely-sensed estimates of surface soil moisture (r2=0.63, 0.50, 0.56 respectively). Simulations ...

Research paper thumbnail of Linking tropical forest structure from regional-scale airborne lidar data to terrestrial ecosystem models

HAL (Le Centre pour la Communication Scientifique Directe), 2019

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of ED-2.2-hydro

ED2 codes for site-level VOD comparison

Research paper thumbnail of Revision

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Research paper thumbnail of Moorcroft northeastern North America evaluation of a terrestrial biosphere model for the forests of Predicting ecosystem dynamics at regional scales : an Supplementary data

This article cites 34 articles, 3 of which can be accessed free Subject collections (145 articles... more This article cites 34 articles, 3 of which can be accessed free Subject collections (145 articles) environmental science (335 articles) ecology Articles on similar topics can be found in the following collections Email alerting service here right-hand corner of the article or click Receive free email alerts when new articles cite this article-sign up in the box at the top http://rstb.royalsocietypublishing.org/subscriptions

Research paper thumbnail of Leaf surface water, not plant water stress, drives diurnal variation in tropical forest canopy water content

New Phytologist, 2021

Variation in canopy water content (CWC) that can be detected from microwave remote sensing of veg... more Variation in canopy water content (CWC) that can be detected from microwave remote sensing of vegetation optical depth (VOD) has been proposed as an important measure of vegetation water stress. However, the contribution of leaf surface water (LW s), arising from dew formation and rainfall interception, to CWC is largely unknown, particularly in tropical forests and other high-humidity ecosystems. We compared VOD data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) and CWC predicted by a plant hydrodynamics model at four tropical sites in Brazil spanning a rainfall gradient. We assessed how LW s influenced the relationship between VOD and CWC. The analysis indicates that while CWC is strongly correlated with VOD (R 2 = 0.62 across all sites), LW s accounts for 61-76% of the diurnal variation in CWC despite being < 10% of CWC. Ignoring LW s weakens the near-linear relationship between CWC and VOD and reduces the consistency in diurnal variation. The contribution of LW s to CWC variation, however, decreases at longer, seasonal to inter-annual, time scales. Our results demonstrate that diurnal patterns of dew formation and rainfall interception can be an important driver of diurnal variation in CWC and VOD over tropical ecosystems and therefore should be accounted for when inferring plant diurnal water stress from VOD measurements.

Research paper thumbnail of Understanding water and energy fluxes in the Amazonia: Lessons from an observation‐model intercomparison

Global Change Biology, 2021

Tropical forests are an important part of global water and energy cycles, but the mechanisms that... more Tropical forests are an important part of global water and energy cycles, but the mechanisms that drive seasonality of their land-atmosphere exchanges have proven challenging to capture in models. Here, we (1) report the seasonality of fluxes of latent heat (LE), sensible heat (H), and outgoing short and longwave radiation at four diverse tropical forest sites across Amazonia-along the equator from the Caxiuanã and Tapajós National Forests in the eastern Amazon to a forest near Manaus, and from the equatorial zone to the southern forest in Reserva Jaru; (2) investigate how vegetation and climate influence these fluxes; and (3) evaluate land surface model performance by comparing simulations to observations. We found that previously identified failure of models to capture observed dry-season increases in evapotranspiration (ET) was | 1803 RESTREPO-COUPE ET al. 1 | INTRODUC TI ON Tropical forests play a major role in the global water and energy cycles, and modulate tropical atmospheric circulation processes,

Research paper thumbnail of Partitioning evapotranspiration with concurrent eddy covariance measurements in a mixed forest

Agricultural and Forest Meteorology, 2020

Research paper thumbnail of Land cover change explains the increasing discharge of the Paraná River

Regional Environmental Change, 2018

Over the past 40 years, the discharge in South America's Paraná River basin has increased despite... more Over the past 40 years, the discharge in South America's Paraná River basin has increased despite no evidence of significant rainfall increases in the basin. In this analysis, we show that the observed multi-decadal increase in discharge can be explained by concomitant changes in land cover that have occurred within the basin during this period. Our analysis also indicates that the peak discharge timing may have shifted concurrently from January/February in the 1970s to March in more recent decades. While land-use effect dominantly alters the long-term temporal dynamics of the river discharge over multi-decades, the change in the seasonality of the discharge can be attributable to the combined effect of the land-use and climate variability. This study suggests that the mean annual discharge is likely to change in the other South American River basins where land transformation is currently taking place, and the shift of the month of peak discharge needs to be taken into consideration to forecast the hydropower generation under changing climate and land conversion. Keywords Land cover change. River discharge. Paraná River basin. Shift of the peak discharge timing. Hydroelectricity generation in Brazil

Research paper thumbnail of Ecosystem heterogeneity and diversity mitigate Amazon forest resilience to frequent extreme droughts

The New phytologist, Jan 22, 2018

The impact of increases in drought frequency on the Amazon forest's composition, structure an... more The impact of increases in drought frequency on the Amazon forest's composition, structure and functioning remain uncertain. We used a process- and individual-based ecosystem model (ED2) to quantify the forest's vulnerability to increased drought recurrence. We generated meteorologically realistic, drier-than-observed rainfall scenarios for two Amazon forest sites, Paracou (wetter) and Tapajós (drier), to evaluate the impacts of more frequent droughts on forest biomass, structure and composition. The wet site was insensitive to the tested scenarios, whereas at the dry site biomass declined when average rainfall reduction exceeded 15%, due to high mortality of large-sized evergreen trees. Biomass losses persisted when year-long drought recurrence was shorter than 2-7 yr, depending upon soil texture and leaf phenology. From the site-level scenario results, we developed regionally applicable metrics to quantify the Amazon forest's climatological proximity to rainfall regime...

Research paper thumbnail of The changing carbon balance of tundra ecosystems: results from a vertically-resolved peatland biosphere model

Environmental Research Letters, Dec 30, 2021

An estimated 1700 Pg of carbon is frozen in the Arctic permafrost and the fate of this carbon is ... more An estimated 1700 Pg of carbon is frozen in the Arctic permafrost and the fate of this carbon is unclear because of the complex interaction of biophysical, ecological and biogeochemical processes that govern the Arctic carbon budget. Two key processes determining the region’s long-term carbon budget are: (a) carbon uptake through increased plant growth, and (b) carbon release through increased heterotrophic respiration (HR) due to warmer soils. Previous predictions for how these two opposing carbon fluxes may change in the future have varied greatly, indicating that improved understanding of these processes and their feedbacks is critical for advancing our predictive ability for the fate of Arctic peatlands. In this study, we implement and analyze a vertically-resolved model of peatland soil carbon into a cohort-based terrestrial biosphere model to improve our understanding of how on-going changes in climate are altering the Arctic carbon budget. A key feature of the formulation is that accumulation of peat within the soil column modifies its texture, hydraulic conductivity, and thermal conductivity, which, in turn influences resulting rates of HR within the soil column. Analysis of the model at three eddy covariance tower sites in the Alaskan tundra shows that the vertically-resolved soil column formulation accurately captures the zero-curtain phenomenon, in which the temperature of soil layers remain at or near 0 °C during fall freezeback due to the release of latent heat, is critical to capturing observed patterns of wintertime respiration. We find that significant declines in net ecosystem productivity (NEP) occur starting in 2013 and that these declines are driven by increased HR arising from increased precipitation and warming. Sensitivity analyses indicate that the cumulative NEP over the decade responds strongly to the estimated soil carbon stock and more weakly to vegetation abundance at the beginning of the simulation.

Research paper thumbnail of Erratum: Monitoring plant functional diversity from space

Nature plants, Mar 14, 2016

Research paper thumbnail of Ecosystem Demography Model, version 2.2 (ED-2.2)

This version contains all the model developments for ED-2.2 and described in Longo et al. (2019) ... more This version contains all the model developments for ED-2.2 and described in Longo et al. (2019) (https://dx.doi.org/10.5194/gmd-2019-45).

Research paper thumbnail of Ecological and Behavioral Drivers of Supplemental Feeding Use by Roe Deer Capreolus capreolus in a Peri-Urban Context

Animals, 2020

Winter supplemental feeding of ungulates potentially alters their use of resources and ecological... more Winter supplemental feeding of ungulates potentially alters their use of resources and ecological interactions, yet relatively little is known about the patterns of feeding sites use by target populations. We used camera traps to continuously monitor winter and spring feeding site use in a roe deer population living in a peri-urban area in Northern Italy. We combined circular statistics with generalized additive and linear mixed models to analyze the diel and seasonal pattern of roe deer visits to feeding sites, and the behavioral drivers influencing visit duration. Roe deer visits peaked at dawn and dusk, and decreased from winter to spring when vegetation regrows and temperature increases. Roe deer mostly visited feeding sites solitarily; when this was not the case, they stayed longer at the site, especially when conspecifics were eating, but maintained a bimodal diel pattern of visits. These results support an opportunistic use of feeding sites, following seasonal cycles and the ...

Research paper thumbnail of The impacts of Amazon forest degradation and fragmentation on energy, water, and carbon cycles

&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;... more 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

Research paper thumbnail of Cluster-based trajectory segmentation with local noise

Data Mining and Knowledge Discovery, 2018

We present a framework for the partitioning of a spatial trajectory in a sequence of segments bas... more We present a framework for the partitioning of a spatial trajectory in a sequence of segments based on spatial density and temporal criteria. The result is a set of temporally separated clusters interleaved by sub-sequences of unclustered points. A major novelty is the proposal of an outlier or noise model based on the distinction between intra-cluster (local noise) and inter-cluster noise (transition): the local noise models the temporary absence from a residence while the transition the definitive departure towards a next residence. We analyze in detail the properties of the model and present a comprehensive solution for the extraction of temporally ordered clusters. The effectiveness of the solution is evaluated first qualitatively and next quantitatively by contrasting the segmentation with ground truth. The ground truth consists of a set of trajectories of labeled points simulating animal movement. Moreover, we show that the approach can streamline the discovery of additional derived patterns, by presenting a novel technique for the analysis of periodic movement. From a methodological perspective, a valuable aspect of this research is that it combines the theoretical investigation with the application and external validation of the segmentation framework. This paves the way to an effective deployment of the solution in broad and challenging fields such as e-science.

Research paper thumbnail of How close are we to a predictive science of the biosphere?

Trends in Ecology & Evolution, 2006

In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipli... more In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipline to a central area of modern climate change research. The development of terrestrial biosphere models that predict the responses of ecosystems to climate and increasing CO 2 levels has highlighted several mechanisms by which changes in ecosystem composition and function might alter regional and global climate. However, results from empirical studies suggest that ecosystem responses can differ markedly from the predictions of terrestrial biosphere models. As I discuss here, the challenge now is to connect terrestrial biosphere models to empirical ecosystem measurements. Only by systematically evaluating the predictions of terrestrial biosphere models against suites of ecosystem observations and experiments measurements will a true predictive science of the biosphere be achieved.

Research paper thumbnail of Building the bridge between animal movement and population dynamics

Philosophical Transactions of the Royal Society B: Biological Sciences, 2010

While the mechanistic links between animal movement and population dynamics are ecologically obvi... more While the mechanistic links between animal movement and population dynamics are ecologically obvious, it is much less clear when knowledge of animal movement is a prerequisite for understanding and predicting population dynamics. GPS and other technologies enable detailed tracking of animal location concurrently with acquisition of landscape data and information on individual physiology. These tools can be used to refine our understanding of the mechanistic links between behaviour and individual condition through ‘spatially informed’ movement models where time allocation to different behaviours affects individual survival and reproduction. For some species, socially informed models that address the movements and average fitness of differently sized groups and how they are affected by fission–fusion processes at relevant temporal scales are required. Furthermore, as most animals revisit some places and avoid others based on their previous experiences, we foresee the incorporation of ...

Research paper thumbnail of Evaluation Of The Ecosystem Demography Model Version 2 (ED2) In North America

Research paper thumbnail of High temperature sensitivity of peat decomposition due to physical-biogeochemical feedback

Research paper thumbnail of Southeast Asian peatland drainage emits 220 Mt of carbon per year, equivalent to 2.2% of global fossil-fuel emissions

Southeast Asian peatlands are climatically important ecosystems, storing approximately 70 billion... more Southeast Asian peatlands are climatically important ecosystems, storing approximately 70 billion tons of carbon. Natural and human-induced droughts are lowering peatland water tables, increasing decomposition and the risk of peat-burning wildfires. The rapid nature of carbon losses arising from peatland drainage and accompanying fire-related losses compared to the slow accumulation of peat means that the effects of peatland drainage are essentially irreversible on human timescales. Here, we use a terrestrial biosphere model incorporating vertically-resolved peatland carbon and water dynamics to predict decomposition and fire in Southeast Asia as a result drainage-induced drying. The model captures observed patterns of interannual and seasonal variation in soil moisture and its soil moisture estimates are a better predictor of observed burned area fraction than either precipitation or remotely-sensed estimates of surface soil moisture (r2=0.63, 0.50, 0.56 respectively). Simulations ...

Research paper thumbnail of Linking tropical forest structure from regional-scale airborne lidar data to terrestrial ecosystem models

HAL (Le Centre pour la Communication Scientifique Directe), 2019

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of ED-2.2-hydro

ED2 codes for site-level VOD comparison

Research paper thumbnail of Revision

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Research paper thumbnail of Moorcroft northeastern North America evaluation of a terrestrial biosphere model for the forests of Predicting ecosystem dynamics at regional scales : an Supplementary data

This article cites 34 articles, 3 of which can be accessed free Subject collections (145 articles... more This article cites 34 articles, 3 of which can be accessed free Subject collections (145 articles) environmental science (335 articles) ecology Articles on similar topics can be found in the following collections Email alerting service here right-hand corner of the article or click Receive free email alerts when new articles cite this article-sign up in the box at the top http://rstb.royalsocietypublishing.org/subscriptions

Research paper thumbnail of Leaf surface water, not plant water stress, drives diurnal variation in tropical forest canopy water content

New Phytologist, 2021

Variation in canopy water content (CWC) that can be detected from microwave remote sensing of veg... more Variation in canopy water content (CWC) that can be detected from microwave remote sensing of vegetation optical depth (VOD) has been proposed as an important measure of vegetation water stress. However, the contribution of leaf surface water (LW s), arising from dew formation and rainfall interception, to CWC is largely unknown, particularly in tropical forests and other high-humidity ecosystems. We compared VOD data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) and CWC predicted by a plant hydrodynamics model at four tropical sites in Brazil spanning a rainfall gradient. We assessed how LW s influenced the relationship between VOD and CWC. The analysis indicates that while CWC is strongly correlated with VOD (R 2 = 0.62 across all sites), LW s accounts for 61-76% of the diurnal variation in CWC despite being < 10% of CWC. Ignoring LW s weakens the near-linear relationship between CWC and VOD and reduces the consistency in diurnal variation. The contribution of LW s to CWC variation, however, decreases at longer, seasonal to inter-annual, time scales. Our results demonstrate that diurnal patterns of dew formation and rainfall interception can be an important driver of diurnal variation in CWC and VOD over tropical ecosystems and therefore should be accounted for when inferring plant diurnal water stress from VOD measurements.

Research paper thumbnail of Understanding water and energy fluxes in the Amazonia: Lessons from an observation‐model intercomparison

Global Change Biology, 2021

Tropical forests are an important part of global water and energy cycles, but the mechanisms that... more Tropical forests are an important part of global water and energy cycles, but the mechanisms that drive seasonality of their land-atmosphere exchanges have proven challenging to capture in models. Here, we (1) report the seasonality of fluxes of latent heat (LE), sensible heat (H), and outgoing short and longwave radiation at four diverse tropical forest sites across Amazonia-along the equator from the Caxiuanã and Tapajós National Forests in the eastern Amazon to a forest near Manaus, and from the equatorial zone to the southern forest in Reserva Jaru; (2) investigate how vegetation and climate influence these fluxes; and (3) evaluate land surface model performance by comparing simulations to observations. We found that previously identified failure of models to capture observed dry-season increases in evapotranspiration (ET) was | 1803 RESTREPO-COUPE ET al. 1 | INTRODUC TI ON Tropical forests play a major role in the global water and energy cycles, and modulate tropical atmospheric circulation processes,

Research paper thumbnail of Partitioning evapotranspiration with concurrent eddy covariance measurements in a mixed forest

Agricultural and Forest Meteorology, 2020

Research paper thumbnail of Land cover change explains the increasing discharge of the Paraná River

Regional Environmental Change, 2018

Over the past 40 years, the discharge in South America's Paraná River basin has increased despite... more Over the past 40 years, the discharge in South America's Paraná River basin has increased despite no evidence of significant rainfall increases in the basin. In this analysis, we show that the observed multi-decadal increase in discharge can be explained by concomitant changes in land cover that have occurred within the basin during this period. Our analysis also indicates that the peak discharge timing may have shifted concurrently from January/February in the 1970s to March in more recent decades. While land-use effect dominantly alters the long-term temporal dynamics of the river discharge over multi-decades, the change in the seasonality of the discharge can be attributable to the combined effect of the land-use and climate variability. This study suggests that the mean annual discharge is likely to change in the other South American River basins where land transformation is currently taking place, and the shift of the month of peak discharge needs to be taken into consideration to forecast the hydropower generation under changing climate and land conversion. Keywords Land cover change. River discharge. Paraná River basin. Shift of the peak discharge timing. Hydroelectricity generation in Brazil

Research paper thumbnail of Ecosystem heterogeneity and diversity mitigate Amazon forest resilience to frequent extreme droughts

The New phytologist, Jan 22, 2018

The impact of increases in drought frequency on the Amazon forest's composition, structure an... more The impact of increases in drought frequency on the Amazon forest's composition, structure and functioning remain uncertain. We used a process- and individual-based ecosystem model (ED2) to quantify the forest's vulnerability to increased drought recurrence. We generated meteorologically realistic, drier-than-observed rainfall scenarios for two Amazon forest sites, Paracou (wetter) and Tapajós (drier), to evaluate the impacts of more frequent droughts on forest biomass, structure and composition. The wet site was insensitive to the tested scenarios, whereas at the dry site biomass declined when average rainfall reduction exceeded 15%, due to high mortality of large-sized evergreen trees. Biomass losses persisted when year-long drought recurrence was shorter than 2-7 yr, depending upon soil texture and leaf phenology. From the site-level scenario results, we developed regionally applicable metrics to quantify the Amazon forest's climatological proximity to rainfall regime...