445 research outputs found
Realized ecological forecast through an interactive Ecological Platform for Assimilating Data (EcoPAD, v1.0) into models
Predicting future changes in ecosystem services is not only highly
desirable but is also becoming feasible as several forces (e.g., available big
data, developed data assimilation (DA) techniques, and advanced
cyber-infrastructure) are converging to transform ecological research into
quantitative forecasting. To realize ecological forecasting, we have
developed an Ecological Platform for
Assimilating Data (EcoPAD, v1.0) into models. EcoPAD (v1.0)
is a web-based software system that automates data transfer and processing
from sensor networks to ecological forecasting through data management,
model simulation, data assimilation, forecasting, and visualization. It
facilitates interactive data–model integration from which the model is
recursively improved through updated data while data are systematically
refined under the guidance of model. EcoPAD (v1.0) relies on data from
observations, process-oriented models, DA techniques, and the web-based
workflow.
We applied EcoPAD (v1.0) to the Spruce and Peatland Responses Under Climatic
and Environmental change (SPRUCE) experiment in northern Minnesota. The
EcoPAD-SPRUCE realizes fully automated data transfer, feeds meteorological
data to drive model simulations, assimilates both manually measured and
automated sensor data into the Terrestrial ECOsystem (TECO) model, and
recursively forecasts the responses of various biophysical and biogeochemical
processes to five temperature and two CO2 treatments in near-real time
(weekly). Forecasting with EcoPAD-SPRUCE has revealed that mismatches in
forecasting carbon pool dynamics are more related to model (e.g., model
structure, parameter, and initial value) than forcing variables, opposite to
forecasting flux variables. EcoPAD-SPRUCE quantified acclimations of methane
production in response to warming treatments through shifted posterior
distributions of the CH4:CO2 ratio and the temperature sensitivity
(Q10) of methane production towards lower values. Different case
studies indicated that realistic forecasting of carbon dynamics relies on
appropriate model structure, correct parameterization, and accurate external
forcing. Moreover, EcoPAD-SPRUCE stimulated active feedbacks between
experimenters and modelers to identify model components to be improved and
additional measurements to be taken. It has become an interactive
model–experiment (ModEx) system and opens a novel avenue for interactive
dialogue between modelers and experimenters. Altogether, EcoPAD (v1.0) acts
to integrate multiple sources of information and knowledge to best inform
ecological forecasting.</p
Predicting malaria dynamics under climate change
Malaria dynamics are closely tied to climate, as rainfed water pools provide the habitat for the Anopheles mosquitoes, and temperature influences this vector's ability to spread disease. Climate change drives shifts in microtopographic controls on the persistence of mosquito habitat and the life cycles of Anopheles vector and Plasmodium parasite, which affect the transmission of malaria. The ability to accurately predict malaria dynamics in the future requires the consideration of the impacts of modifications in ecohydrologic system under climate change on these shifts.
The primary goal of this research is to investigate the relationships between the dynamics of malaria and changes in the ecohydrologic system due to the acclimation of vegetation under elevated atmospheric CO2 condition and temperature increase. We also aim to understand how the dominant controls of malaria interact under environmental perturbations by quantitatively analyzing changes in malaria incidence rates. Here, a coupled ecohydrology-malaria dynamics model is developed to predict malaria dynamics under projected climate change. The impacts of ecologic acclimation on soil moisture and persistence of ponded water that provide habitat for mosquitoes are captured using a coupled multi-layer canopy and physically-based flow surface-subsurface modeling approach. The transmission of malaria in response to these impacts and temperature increase are assessed by using a stochastic meta-popolation simulation model. We show that impacts of elevated CO2 and temperature have opposing effects on malaria prevalence. While air temperature increase shortens the life cycles of Anopheles and Plasmodium and increases the risk of spreading the disease, lower soil moisture resulting from increasing evapotranspiration reduces the habitat suitability for mosquitoes. The interplay between air temperature increases and soil moisture reduction under climate change leads to a smaller net increase in environmental suitability for malaria transmission than previously thought. In addition, we found larger net increase of malaria incidence under high temperature increase due to its nonlinear effects on the life cycles of vectors and parasites. The models and methods used are generalized and can be applied to other mosquito-borne diseases
Customization, extension and reuse of outdated hydrogeological software
Each scientist is specialized in his or her field of research and in the tools that he or she uses during the research in a specified site. Thus, he or she is the most suitable person for improving the tools by overcoming their limitations to realize faster and higher quality analysis. However, most scientists are not software developers. Hence, it is necessary to provide them with an easy approach that enables non-software developers to improve and customize their tools. This paper presents an approach for easily improving and customizing any hydrogeological software. It is the result of experiences with updating several interdisciplinary case studies. The main insights of this approachhave been demonstrated using four examples: MIX (FORTRAN-based), BrineMIX (C++-based), EasyQuim and EasyBal (both spreadsheet-based). The improved software has been proven to be a better tool for enhanced analysis by substantially reducing the computation time and the tedious processing of the input and output data files
2016 International Land Model Benchmarking (ILAMB) Workshop Report
As earth system models (ESMs) become increasingly complex, there is a growing need for comprehensive and multi-faceted evaluation of model projections. To advance understanding of terrestrial biogeochemical processes and their interactions with hydrology and climate under conditions of increasing atmospheric carbon dioxide, new analysis methods are required that use observations to constrain model predictions, inform model development, and identify needed measurements and field experiments. Better representations of biogeochemistryclimate feedbacks and ecosystem processes in these models are essential for reducing the acknowledged substantial uncertainties in 21st century climate change projections
Assessing the agricultural system and the Carbon cycle under climate change in Europe using a dynamic global vegetation model
Several recent studies predicted changes in the climatic conditions in Europe driven by the increased atmospheric CO2 concentration due anthropogenic activities. The climate change can affect the agriculture through many aspects of crop production over the European continent. Not only plant productivity, but also geographical shifts of cultivation areas, changes in crop phenology, in land use, and in soil carbon stocks have to be taken into account for assessments of the next future. This study provides a potentially powerful baseline to perform integrated assessments on the impacts of the changing climate by assessing crop production with a single integrated framework for large-scale studies. Not only crops and natural vegetation in a single Dynamic Global Vegetation Model, the LPJ-C, but also potential and water-limited crop production are included within the same biosphere scheme. The LPJ-C is extended to simulate not only natural biomes, but also crops. We perform an optimization procedure, which provides a set of crop parameters used in the regional assessment over Europe. Further, we used the resulting modelling framework to study the changes of potential production of maize and wheat together with the shift in their potential growing area. The results show that wheat yield will suffer from a decline, but fertilization due to the CO2 enriched atmosphere will compensate this effect. For maize, cultivation will clearly expand towards north and east. Since maize, as a C4 plant, is mostly unaffected by the CO2 fertilization effect, the shorter growing season will lead to a lower net primary productivity, while the mean over the continent will increase according to the large geographical spread. Furthermore, LPJ-C is able to reproduce the observed relative increase of water use efficiency under water-limited conditions and a CO2 fertilization effect. The improved water use efficiency of wheat leads to a relatively smaller transpiration per unit of biomass, so that precipitation will partially satisfy the transpiration demand. On the other hand, wheat will suffer from an increase of yield variability and a higher frequency of extreme crop failures. Even though maize potential distribution will be enlarged, the yield will be affected by strong losses, unless largely improved irrigation will satisfy the increased water demand. We perform also the coupling of LPJ-C with the land-use model KLUM, as a connection between a profit maximization procedure for land allocation and a process-based description of crop production. The coupled system showed that temperature would play a major role in the soil carbon dynamics over the expected northward shift of crops. However, important changes have to be expected for distribution of "warm" cereals as rice and maiz
Modelação de pradarias marinhas intertidais numa laguna costeira mesotidal
Seagrass meadows are important habitats of marine plants, adapted to
the colonization of coastal and estuarine environments, which provide
important functions within the ecosystem. The remarkable decline of
seagrass meadows at regional/local (Ria de Aveiro) and global scales
has presented however negative implications for the sustainability of the
ecosystems where they follow this trend. In this context, the main
objective of this work was to improve the present knowledge about
seagrass dynamics in the Ria de Aveiro, from a multidisciplinary
viewpoint (experimental data collection and treatment and numerical
modelling), as well as to anticipate potential changes at the system level
in these communities. Therefore, it is intended to contribute to the
promotion of adequate management and conservation strategies to
minimize its decline and enhance its recovery. From the application of a
conceptual DSPIR framework (Drivers-Pressures-State-Impacts-
Responses), the results pointed that gradual changes in hydrodynamic
characteristics are the basis of the local decline of these communities,
presently colonized by monospecific intertidal meadows of Zostera
noltei. The scarce availability of seagrass models is even more
prominent when dealing with intertidal communities, subject to
alternating periods of exposure to air and submergence. As so, the
inherent peculiarities of intertidal seagrass Z. noltei communities were
investigated, showing a greater influence of the sedimentary
characteristics on the relative water content of the plant, rather than the
air exposure time. Afterwards, it was developed a seagrass biological
model together with a desiccation model of the plant, in order to
suppress the previously identified gap, both of which were later coupled
to the water quality model (Delft3D-WAQ). The numerical model was
calibrated using experimental data collected in the study area (Mira
Channel), showing a reliable reproduction of the state variables
described by means of above and belowground biomass. However, the
present set up needs to be improved, namely in what regards sedimentplant
interface and internal nutrient dynamics, before it can be applied to
other systems with similar challenges. The performance of the
numerical model was analysed through different methodologies that
presented divergent results, which suggests the application of further
approaches for a robust conclusion. A sensitivity analysis was
computed, showing that the parameters used to describe the
dependence of the ambient temperature (water and air) are the most
sensitive, suggesting that these should be particularly addressed in
future experimental surveys, by increasing the frequency of the in situ
measurements. Two exploratory simulations of extreme event, extreme
river flow and heat-wave, respectively showed a decrease in the
favourable conditions for seagrass presence, according to the water
velocity and salinity; and clear negative impacts on seagrass growth.
Following a prospective viewpoint, different evolutionary scenarios to
the future, resulting from the foreseen climate change, were set
according to the more and less pessimistic projection (RCP 4.5 and
RCP 8.5). The numerical model projections pointed out for a noticeable
loss of colonised areas by seagrass (between around 30 and 70%,
respectively) compared to the present situation. The multiple stressors analysed generally showed a synergistic effect
on the loss of the relative area of seagrass, compared to the isolated
sum of each of the factors, which highlights the complex and intrinsic
relations established between them. The areas colonized by seagrass
meadows that showed greater resilience, to the two simulated climate
change scenarios, are located in the south and northwest areas of the
central lagoon. The spatial distribution of the anomalies between the
reference and the climate change scenarios, showed no uniform pattern
of variation, occurring areas with descreased favourable conditions for
seagrass presence, but also some areas that verified an improvement of
these conditions. For a more effective and holistic approach to the
natural evolution and modelling of these systems, a wider spatial and
temporal coverage of biotic and abiotic descriptors of these communities
should be performed. Moreover, the overview of the ongoing and
forthcoming anthropogenic actions must also be included, in the context
of the socio-economic development of the region, as well as the
framework of the future scenarios in the scope of climate change
(temporal scale referred to the end of the century). As so, the
management actions can be implemented to promote the resilience of
these habitats and assure the services provided by the ecosystem.As pradarias marinhas constituem importantes habitats de plantas
superiores, adaptadas à colonização de ambientes costeiros e
estuarinos, que desempenham importantes funções nestes
ecossistemas. O seu declÃnio acentuado verificado a escalas
regionais/locais (Ria de Aveiro) e globais tem, no entanto, apresentado
implicações nefastas para a sustentabilidade dos ecossistemas onde
estão inseridas. Neste contexto, o objectivo principal deste trabalho
consistiu em aprofundar o conhecimento presente da dinâmica das
pradarias marinhas na Ria de Aveiro, sob o ponto de vista
multidisciplinar (colheita e tratamento de dados experimentais e
modelação numérica), bem como prever as potenciais alterações ao
nÃvel do sistema nestas comunidades. Desta forma, pretende-se
contribuir para a promoção de estratégias de conservação adequadas
para minimizar o seu declÃnio e potenciar a sua recuperação. Partindo
da aplicação de um modelo conceptual DPSIR (Drivers-Pressures-
State-Impacts-Responses), concluiu-se que as alterações graduais nas
caracterÃsticas hidrodinâmicas estão na base do declÃnio local destas
comunidades, presentemente colonizadas por pradarias
monoespecÃficas intertidais de Zostera noltei. A escassez de modelos
numéricos de pradaria é acentuada, sendo ainda mais proeminente
quando se tratam de comunidades intertidais, sujeitas a perÃodos
alternados de exposição ao ar e submersão. Desta forma, as
particularidades inerentes às comunidades de pradarias intertidais
foram investigadas, mostrando maior influência das caracterÃsticas
sedimentares no teor relativo de água da planta, em detrimento do
tempo de exposição ao ar. Posteriormente, foi desenvolvido um modelo
biológico de pradaria, juntamente com um modelo de dessecação da
planta, com vista a suprimir a lacuna previamente identificada, sendo
ambos posteriormente acoplados ao modelo de qualidade da água
(Delft3D-WAQ). Utilizando os dados experimentais colhidos na área de
estudo (Canal de Mira) calibrou-se o modelo numérico, tendo-se
verificado uma reprodução fiável das variáveis-estado descritas pela
biomassa aérea e subterrânea. Porém, a presente configuração requer
melhorias adicionais, nomeadamente no que respeita à interface
sedimento-planta e dinâmica interna de nutrientes, previamente a ser
passÃvel de ser aplicado a outros sistemas com desafios semelhantes.
O desempenho do modelo numérico foi analisado por diferentes
metodologias que apresentaram resultados divergentes, o que sugere a
necessidade de desenvolvimento e aplicação de metodologias
adicionais para uma conclusão robusta. Foi realizada uma análise de
sensibilidade, que permitiu aferir que os parâmetros usados para
descrever a dependência da temperatura ambiente (água e ar) são os
mais sensÃveis. Deste modo, salienta-se a sua potencial importância e
sugere-se a sua consideração em planeamentos experimentais futuros
com maior frequência de amostragem nas medições in situ. Numa
abordagem exploratória, simularam-se dois eventos extremos, caudal
fluvial extremo e onda de calor, tendo os resultados apresentado,
respectivamente, uma diminuição das condições favoráveis para a
presença de pradarias em termos de velocidade da corrente e
salinidade, e um claro decréscimo no crescimento da planta. Seguindo uma abordagem prospectiva, estabeleceram-se diferentes
cenários evolutivos para o futuro, resultantes das expectáveis
alterações climáticas, de acordo com a projecção mais e menos
pessimista (RCP 4.5 e RCP 8.5). As previsões numéricas obtidas
indicam uma perda acentuada de áreas colonizadas por pradarias
marinhas (entre aproximadamente 30 e 70%, respectivamente)
comparativamente à situação presente. As áreas colonizadas por
pradarias que mostraram uma maior resiliência, nos dois cenários de
alterações climáticas, situam-se na zona sul e noroeste da laguna
central. Na análise espacial da anomalia entre o cenário de referência e
de alterações climáticas, não se verificou um padrão uniforme, havendo
áreas que apresentam um decréscimo nas condições favoráveis para a
presença de pradarias marinhas, simultaneamente à ocorrência de
áreas que apontam para um melhoramento das mesmas condições.
Para uma abordagem mais efectiva e holÃstica da evolução natural e
modelação destes sistemas, deve considerar-se uma maior cobertura
espacial e temporal dos descritores bióticos e abióticos destas
comunidades. Deve ser ainda incluÃdo o levantamento das actividades
antropogénicas decorrentes e previstas no contexto do
desenvolvimento socio-económico da região (escala temporal até meio
do século), e ainda, deve ser feito o enquadramento nos cenários
futuros no contexto das alterações climáticas (escala temporal até final
do século), para que medidas de gestão possam ser implementadas no
sentido de promover a resiliência destes habitats, de forma a garantir os
serviços prestados.Projecto LAGOONS – FP7/2007-2013;
Projecto AquiMap (MAR-02.01.01-FEAMP-0022)Programa Doutoral em Biologi
Modelling Human-Fire Interactions: Combining Alternative Perspectives and Approaches
Although it has long been recognised that human activities affect fire regimes, the interactions between humans and fire are complex, imperfectly understood, constantly evolving, and lacking any kind of integrative global framework. Many different approaches are used to study human-fire interactions, but in general they have arisen in different disciplinary contexts to address highly specific questions. Models of human-fire interactions range from conceptual local models to numerical global models. However, given that each type of model is highly selective about which aspects of human-fire interactions to include, the insights gained from these models are often limited and contradictory, which can make them a poor basis for developing fire-related policy and management practices. Here, we first review different approaches to modelling human-fire interactions and then discuss ways in which these different approaches could be synthesised to provide a more holistic approach to understanding human-fire interactions. We argue that the theory underpinning many types of models was developed using only limited amounts of data and that, in an increasingly data-rich world, it is important to re-examine model assumptions in a more systematic way. All of the models are designed to have practical outcomes but are necessarily simplifications of reality and as a result of differences in focus, scale and complexity, frequently yield radically different assessments of what might happen. We argue that it should be possible to combine the strengths and benefits of different types of model through enchaining the different models, for example from global down to local scales or vice versa. There are also opportunities for explicit coupling of different kinds of model, for example including agent-based representation of human actions in a global fire model. Finally, we stress the need for co-production of models to ensure that the resulting products serve the widest possible community
- …