scholarly journals Precipitation's complicated role in driving the abundance of an emerging disease vector in an urban, arid landscape

2021 ◽  
Author(s):  
Erica Newman ◽  
Xiao Feng ◽  
Kathleen Walker ◽  
Steven Young ◽  
Kirk Smith ◽  
...  
Keyword(s):  
Water Availability ◽  
Daily Precipitation ◽  
Emerging Diseases ◽  
Local Scale ◽  
Anthropogenic Sources ◽  
Disease Vectors ◽  
Maricopa County ◽  
Disease Vector ◽  
Oviposition Sites ◽  
Landscape Level

Understanding population dynamics of disease vectors is a pressing challenge for human health. A major challenge is that landscape-level models for organisms like mosquitoes must also account for the highly local scale of their reproductive biology. Aedes aegypti, a vector of multiple emerging diseases, has been increasing in abundance and range in desert population centers, where water availability may be limiting. We examined daily precipitation and Ae. aegypti abundance in the urbanized Maricopa County (metropolitan Phoenix), Arizona, USA for >660 trapping locations over 3 years. By connecting daily precipitation to subsequent trapped abundances of mosquitoes through kriging, we determined the timing and amount of precipitation that lead to large outbreaks, and thresholds of interference with mosquito development. In this context, anthropogenic sources of water likely supersede the limiting effect of precipitation by providing constantly available oviposition sites, and could therefore be targeted for disease management.

scholarly journals On observational and modelling strategies targeted at regional carbon exchange over continents

2009 ◽  
Vol 6 (1) ◽  
pp. 1317-1343 ◽  
Author(s):  
C. Gerbig ◽  
A. J. Dolman ◽  
M. Heimann
Keyword(s):  
Spatial Scales ◽  
Regional Scale ◽  
Local Scale ◽  
Anthropogenic Sources ◽  
Carbon Exchange ◽  
Top Down ◽  
Bottom Up ◽  
Modelling Strategies ◽  
The Impact ◽  
Up Scaling

Abstract. Estimating carbon exchange at regional scales is paramount to understanding feedbacks between climate and the carbon cycle, but also to verifying climate change mitigation such as emission reductions and strategies compensating for emissions such as carbon sequestration. This paper discusses evidence for a number of important shortcomings of current generation modelling frameworks designed to provide regional scale budgets. Current top-down and bottom-up approaches targeted at deriving consistent regional scale carbon exchange estimates for biospheric and anthropogenic sources and sinks are hampered by a number of issues: We show that top-down constraints using point measurements made from tall towers, although sensitive to larger spatial scales, are however influenced by local areas much stronger than previously thought. On the other hand, classical bottom-up approaches using process information collected at the local scale, such as from eddy covariance data, need up-scaling and validation on larger scales. We therefore argue for a combination of both approaches, implicitly providing the important local scale information for the top-down constraint, and providing the atmospheric constraint for up-scaling of flux measurements. Combining these data streams necessitates quantifying their respective representation errors, which are discussed. The impact of these findings on future network design is highlighted, and some recommendations are given.

scholarly journals Risk of Chagas disease vectors' presence at a local scale in Central Chile

Medwave ◽  
2016 ◽  
Vol 16 (Suppl6) ◽  
pp. 6727-6727
Author(s):  
Antonella Bacigalupo Bacigalupo ◽  
Alberto Alaniz Baeza ◽  
Patricio Arroyo Saldías ◽  
Héctor Jaime Hernández Palma ◽  
Pedro Cattan Ayala
Keyword(s):  
Chagas Disease ◽  
Local Scale ◽  
Disease Vectors ◽  
Central Chile ◽  
Chagas Disease Vectors

Local-scale secondary water resources modulate seasonal water limitation across Africa

2021 ◽  
Author(s):  
Çağlar Küçük ◽  
Sujan Koirala ◽  
Nuno Carvalhais ◽  
Diego G. Miralles ◽  
Markus Reichstein ◽  
...  
Keyword(s):  
Water Resources ◽  
Spatial Variation ◽  
Decay Rate ◽  
Water Availability ◽  
Land Surface ◽  
Spatial Scales ◽  
Shallow Groundwater ◽  
Local Scale ◽  
Gradient Boosting ◽  
Water Limitation

<p>Drylands contribute strongly to global biogeochemical cycles and their variability. While precipitation is the main driver of plant water availability, secondary water resources like shallow groundwater and lateral convergence of soil moisture may play important roles in supporting ecosystems against water limitation at the local scale. Despite their strong relevance, the effects of secondary water resources are often ignored or highly uncertain in studies over large spatial domains. </p><p>Here, we aimed to quantify the degree to which land properties control secondary water resources over water-limited regions in Africa. To do so, we first detected the seasonal decay periods of Fractional Vegetation Cover (FVC) time series from the changes in FVC over time at daily temporal resolution. FVC data is provided by the EUMETSAT from the image acquisitions from the geostationary satellite MSG. We then calculated the seasonal decay rate of FVC (λ) and used it with other climate, land and vegetation properties at 5 km spatial resolution. We hypothesized that any secondary water resource should slow down vegetation decays in drylands. We used gradient boosting machine learning to model λ and constrained the model according to the hypothesis. Finally, we used Shapley additive explanations in order to quantify the effects of land properties on spatial variation of the modelled λ.</p><p>Model output (NSE = 0.55) revealed that over drylands of Africa, ∼1/3 of spatial variation of λ is attributed to land properties, half of which is attributed to direct land effects while the rest is attributed to the land interactions with climate and vegetation. Though at local scales, this attribution gets much stronger over hotspots with strong secondary water resources, i.e., shallow groundwater. Spatially, land attributed variations of λ show that vegetation decays slower in regions with shallow groundwater and faster in regions where land surface is disconnected from the groundwater. Topographic complexity is another important factor, with slower vegetation decay in complex terrain, likely due to enhanced lateral moisture convergence. Moreover, these responses intensify with increasing climatological water limitation. </p><p>We found strong effects of land parameters on seasonal vegetation decay rate, spatially structured but at local scales. This highlights the importance of local scale processes affecting water availability in drylands not only at local but also continental to global scales and shows the need of bridging processes across spatial scales in regional-to-global hydrological and vegetation models.</p>

Leaf tissue water relations in tree species from contrasting habitats within the upper Rio Negro forests of the Amazon region

2012 ◽  
Vol 28 (5) ◽  
pp. 519-522 ◽  
Author(s):  
M. A. Sobrado
Keyword(s):  
Water Relations ◽  
Water Availability ◽  
Tree Species ◽  
Leaf Tissue ◽  
Soil Characteristics ◽  
Local Scale ◽  
Tissue Water ◽  
Rio Negro ◽  
Contrasting Habitats ◽  
Species Specific

The landscape of the upper Rio Negro basin (North Amazon) exhibits distinctive habitats that are associated with differential soil characteristics and topographical conditions as well as species composition (Herrera et al. 1978). The mixed forests thrive on well-structured oxisols on slightly more elevated areas. The valleys with sandy podzols are occupied by the ‘Amazon caatinga’ complex with three distinct zones: the bottom valley and the gentle slopes, both of which have closed forests, and the sandy domes with open forests (‘bana’ or sclerophyllous forest; Breimer 1985). From the mixed forest towards the caatinga valley-slope-dome habitats, the leaf δ15N signatures become increasingly negative, suggesting a trend in N limitation in the same direction (Sobrado 2010). Thus, negative leaf δ15N signatures depleted in 15N compared with the soil indicate a very tight N cycle in all of the habitats. Water availability follows a similar pattern from the top of the oxisol towards the flooded valley bottom of the caatinga, with extreme water-table fluctuations in the sandy domes (Klinge 1978). Thus, parallel variation in nutrient and water availabilities exist in this area that are associated with soil characteristics and topography. Under such contrasting habitats, species-specific responses would be linked to particular conditions of the habitat at a local scale (Comita & Engelbrecht 2009, Engelbrecht et al. 2007). A number of studies in these habitats have shown that this is the case for soil fertility (Coomes 1997, Medina et al. 1990, Sobrado 2010, Sobrado & Medina 1980). Similarly, the hydraulic characteristics and long-term water use are species specific and related to particular conditions of the habitat at the local scale (Sobrado 2010). In this report, it was hypothesized that the leaf tissue water relations of species thriving in different habitats may reflect the water availability at the particular sites as well. The leaf tissue water relations of species thriving in the extreme nutrient and water-supply conditions of the sandy domes from the caatinga complex have been previously studied in detail (Sobrado 2009a). However, these data are currently not available for the species that thrive in the surrounding area of the closed forests, and importantly, such information would allow for a comparison across habitats. Therefore, the present study assessed the minimum leaf water potential (midday) under field conditions as well as the leaf tissue water relations by using pressure-volume analysis of dominant tree species in the top canopy of these high-stature forests.

scholarly journals Association of functional trait variation of Quercus castanea with temperature and water availability gradients at the landscape level

2020 ◽  
Vol 98 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Libny Ingrid Lara-De La Cruz ◽  
Felipe García-Oliva ◽  
Ken Oyama ◽  
Antonio González Rodríguez
Keyword(s):  
Functional Traits ◽  
Water Availability ◽  
Phenotypic Variability ◽  
Chlorophyll Concentration ◽  
Geographical Area ◽  
Leaf Thickness ◽  
Leaf Mass Per Area ◽  
Altitudinal Distribution ◽  
Precipitation Seasonality ◽  
Landscape Level

Background: Phenotypic variability of tree species is often associated to environmental factors. Quercus castanea is a Mexican red oak with a wide geographical and altitudinal distribution along contrasting environments. It is the most abundant oak species in the Cuitzeo basin, which is characterized by highly heterogeneous environmental conditions.  Hypothesis: We hypothesized that gradients in temperature, precipitation and soil characteristics across the distribution of Q. castanea within the Cuitzeo basin promote variability in functional traits related to the adjustment to differential water availability at a landscape level. Studied species: Quercus castanea Née (Fagaceae). Study site and years of study: Cuitzeo basin in Central Mexico. 2015-2016. Methods: We quantified leaf chlorophyll concentration (CC), leaf area (LA), leaf thickness (LT), leaf mass per area (LMA) and the Huber value (HV) in 10 individuals from 22 populations of Q. castanea throughout the basin. Results: Despite the relatively small geographical area (4,000 km2), our results revealed significant differentiation among populations in the studied functional traits. The strongest variation found was in LT, which was negatively correlated with precipitation seasonality. This pattern is opposite to previous reports on Mediterranean oaks but similar to tropical oaks and suggests that the combination with other traits such as leaf phenology is important in the response to water availability. Conclusions:  Significant functional differences exist among populations of Q. castanea separated by a few kilometers in the heterogenous landscape of the Cuitzeo basin. This species shows clearly sclerophyllous leaves, but leaf thickness varies to a considerable degree across populations.

The AWESOME Project: A decision analytic framework for managing Water Energy Food and Ecosystems across sectors and scales in the South Mediterranean

2021 ◽  
Author(s):  
Elena Matta ◽  
Matteo Giuliani ◽  
Ruslana Palatnik ◽  
Morderchai Shechter ◽  
Christiane Pyka ◽  
...  
Keyword(s):  
River Basin ◽  
Water Availability ◽  
Systems Analysis ◽  
Local Scale ◽  
Local Economy ◽  
Nile River ◽  
Analytic Framework ◽  
The South ◽  
Macro Scale ◽  
Nile River Basin

<p>Rapid population growth and rising economic prosperity are imperatively challenging the South Mediterranean and the African North-East to a point where they may compromise the sustainable use of natural resources. In those regions, the demand for water, energy, food, and the preservation of ecosystems are expected to increase relevantly. Transboundary rivers like the Nile River Basin represent an enormous source of water, energy, food, and ecosystems (WEFE), which often brings conflicts and individualistic policies among the sharing countries. The adoption of integrated and participatory approaches that explicitly account for the WEFE Nexus are necessary to explore multisectoral synergies and tradeoffs and to generate shared economic, environmental, and societal benefits.</p><p>Focused on the Nile River Basin and born in this context, we present here the AWESOME project (i.e. mAnaging Water, Ecosystems and food across sectors and Scales in the sOuth Mediterranean), whose main objective is developing a decision-analytic framework based on a multi-level, integrated WEFE model to address the Nexus and explore the interdependencies and feedbacks across a hierarchy of spatial scales, from the macroeconomic development (macro), to regional planning (meso), down to the single farm (local).</p><p>At the local scale, a demo-site of smart agricultural solutions (soilless agriculture, e.g., hydroponics, aquaponics) is currently under construction, and it will provide indicators on effectiveness and sustainability of these new technologies to back up existing systems in a dryer future. The study on site will also demonstrate the performance of such a technology within its local economy and ecosystem. At the meso scale, we are developing a decision-analytic framework covering the course of the Nile River Basin, from the Grand Renaissance Dam (GERD) in Ethiopia up to the Nile Delta, based on hydrological models and combined with the results of systems analysis methods with advanced a-posteriori multi-objective optimization algorithms. We plan to simulate existing water availability, water distributions system and new agricultural technologies, upscaling the local scale assessments while downscaling the climate, energy, crop, and ecosystems projections at the macro scale. This approach allows the design of a set of efficient solutions and associated performance with respect to the WEFE multidimensional assessment space, where stakeholders and policy makers will be able to explore multisectoral tradeoffs and negotiate potential compromise alternatives.</p><p>We expect that AWESOME will make substantial progress in complex systems analysis to support the transition towards a more sustainable and resilient agriculture along the Nile River Basin under diverging water availability and demand due to the projected impacts of changing climate and society.</p>

scholarly journals Streamflow Alterations, Attributions, and Implications in Extended East Rapti Watershed, Central-Southern Nepal

2020 ◽  
Vol 12 (9) ◽  
pp. 3829 ◽  
Author(s):  
Vishnu Prasad Pandey ◽  
Dibesh Shrestha ◽  
Mina Adhikari ◽  
Shristi Shakya
Keyword(s):  
Water Availability ◽  
Anthropogenic Activities ◽  
Water Security ◽  
Anthropogenic Sources ◽  
Groundwater Abstraction ◽  
River Health ◽  
Aquatic Biodiversity ◽  
Floods And Droughts ◽  
Relationship Of

Streamflow alteration and subsequent change in long-term average, seasonality, and extremes (e.g., floods and droughts) may affect water security, which is a major concern in many watersheds across the globe. Both climatic and anthropogenic activities may contribute to such changes. Therefore, this study assesses: (i) Streamflow and precipitation trends to identify streamflow alterations in the Extended East Rapti (EER) watershed in central-southern Nepal; (ii) relationship of the alterations to climatic and anthropogenic sources; and (iii) implications of streamflow changes to the socio-environmental system. The trends in streamflow were analyzed for pre-and post-1990 periods considering the abrupt shift in temperature trend in 1990. Results showed a general decreasing trends in discharge post-1990 in the EER watershed. Human activities have significantly contributed in altering streamflow in the EER. Human-induced streamflow alterations have affected the water availability, food security, river health, aquatic biodiversity, and groundwater abstraction in the EER watershed.

scholarly journals A native annual forb locally excludes a closely related introduced species that co-occurs in oak-savanna habitat remnants

AoB Plants ◽  
2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Jens C Johnson ◽  
Jennifer L Williams
Keyword(s):  
Introduced Species ◽  
Water Availability ◽  
Native Species ◽  
Environmental Influence ◽  
Direct Interaction ◽  
Local Scale ◽  
Vital Rates ◽  
Native Plant ◽  
Average Fitness

Abstract Despite the ubiquity of introduced species, their long-term impacts on native plant abundance and diversity remain poorly understood. Coexistence theory offers a tool for advancing this understanding by providing a framework to link short-term individual measurements with long-term population dynamics by directly quantifying the niche and average fitness differences between species. We observed that a pair of closely related and functionally similar annual plants with different origins—native Plectritis congesta and introduced Valerianella locusta—co-occur at the community scale but rarely at the local scale of direct interaction. To test whether niche and/or fitness differences preclude local-scale long-term coexistence, we parameterized models of competitor dynamics with results from a controlled outdoor pot experiment, where we manipulated densities of each species. To evaluate the hypothesis that niche and fitness differences exhibit environmental dependency, leading to community-scale coexistence despite local competitive exclusion, we replicated this experiment with a water availability treatment to determine if this key limiting resource alters the long-term prediction. Water availability impacted population vital rates and intensities of intraspecific versus interspecific competition between P. congesta and V. locusta. Despite environmental influence on competition our model predicts that native P. congesta competitively excludes introduced V. locusta in direct competition across water availability conditions because of an absence of stabilizing niche differences combined with a difference in average fitness, although this advantage weakens in drier conditions. Further, field data demonstrated that P. congesta densities have a negative effect on V. locusta seed prediction. We conclude that native P. congesta limits abundances of introduced V. locusta at the direct-interaction scale, and we posit that V. locusta may rely on spatially dependent coexistence mechanisms to maintain coexistence at the site scale. In quantifying this competitive outcome our study demonstrates mechanistically how a native species may limit the abundance of an introduced invader.

scholarly journals On observational and modelling strategies targeted at regional carbon exchange over continents

2009 ◽  
Vol 6 (10) ◽  
pp. 1949-1959 ◽  
Author(s):  
C. Gerbig ◽  
A. J. Dolman ◽  
M. Heimann
Keyword(s):  
Spatial Scales ◽  
Regional Scale ◽  
Local Scale ◽  
Anthropogenic Sources ◽  
Carbon Exchange ◽  
Top Down ◽  
Bottom Up ◽  
Modelling Strategies ◽  
The Impact ◽  
Up Scaling

Abstract. Estimating carbon exchange at regional scales is paramount to understanding feedbacks between climate and the carbon cycle, but also to verifying climate change mitigation such as emission reductions and strategies compensating for emissions such as carbon sequestration. This paper discusses evidence for a number of important shortcomings of current generation modelling frameworks designed to provide regional scale budgets from atmospheric observations. Current top-down and bottom-up approaches targeted at deriving consistent regional scale carbon exchange estimates for biospheric and anthropogenic sources and sinks are hampered by a number of issues: we show that top-down constraints using point measurements made from tall towers, although sensitive to larger spatial scales, are however influenced by local areas much more strongly than previously thought. On the other hand, classical bottom-up approaches using process information collected at the local scale, such as from eddy covariance data, need up-scaling and validation on larger scales. We therefore argue for a combination of both approaches, implicitly providing the important local scale information for the top-down constraint, and providing the atmospheric constraint for up-scaling of flux measurements. Combining these data streams necessitates quantifying their respective representation errors, which are discussed. The impact of these findings on future network design is highlighted, and some recommendations are given.

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