scholarly journals Leaf Habit and Stem Hydraulic Traits Determine Functional Segregation of Multiple Oak Species along a Water Availability Gradient

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 894
Author(s):  
Maribel Arenas-Navarro ◽  
Felipe García-Oliva ◽  
Teresa Terrazas ◽  
Andrés Torres-Miranda ◽  
Ken Oyama
Keyword(s):  
Water Availability ◽  
Species Coexistence ◽  
Regional Scale ◽  
Functional Space ◽  
Niche Overlap ◽  
Functional Trait ◽  
Leaf Life Span ◽  
Leaf Habit ◽  
Wide Range ◽  
Species Segregation

Oaks are a dominant woody plant genus in the northern hemisphere that occupy a wide range of habitats and are ecologically diverse. We implemented a functional trait approach that included nine functional traits related to leaves and stems in order to explain the species coexistence of 21 oak species along a water availability gradient in a temperate forest in Mexico. This particular forest is characterized as a biodiversity hotspot, with many oak species including some endemics. Our main aim was to investigate whether the different oak species had specific trait associations that allow them to coexist along an environmental gradient at regional scale. First, we explored trait covariation and determined the main functional dimensions in which oaks were segregated. Second, we explored how environmental variation has selected for restricted functional dimensions that shape oak distributions along the gradient, regardless of their leaf life span or phylogeny (section level). Third, we quantified the niche overlap between the oak functional spaces at different levels. The analyzed species showed three functional dimensions of trait variation: a primary axis related to the leaf economic spectrum, which corresponds to the segregation of the species according to leaf habit; a second axis that reflects the stem hydraulic properties and corresponds to species segregation followed by phylogenetic segregation, reflecting some degree of trait conservatism, and a third axis, represented mainly by leaf area and plant height, that corresponds to species segregation. Finally, our findings indicated that the functional space measured with leaf traits and stem traits such as hydraulic capacity was integrally linked to niche differentiation. This linkage suggests that the earliest mechanism of species segregation was related to habitat suitability and that the stem hydraulic trade-off reflects differences between phylogenetic sections; these traits may promote coexistence between distantly related oak species.

scholarly journals Energetic increases lead to niche packing in deep-sea wood falls

2018 ◽  
Vol 14 (9) ◽  
pp. 20180294 ◽  
Author(s):  
Craig R. McClain ◽  
Clifton Nunnally ◽  
Abbie S. A. Chapman ◽  
James P. Barry
Keyword(s):  
Species Richness ◽  
Deep Sea ◽  
Species Coexistence ◽  
Functional Space ◽  
Niche Overlap ◽  
Niche Space ◽  
Environmental Capacity ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Space Expansion

Mechanisms leading to variation in diversity over energetic gradients continue to challenge ecologists. Changes in diversity may reflect the environmental capacity to support species' coexistence through increased niche packing or niche space expansion. Current ecological theory predicts that increases in energy may lead to both scenarios but not their relative strengths. We use experimental deep-sea, wood-fall communities, where energy supply can be controlled, to test for the importance of niche expansion and packing in functional space over an energetic gradient. Invertebrate communities were identified and counted from 16 Acacia sp. logs ranging in size from 0.6 to 20.6 kg in mass (corresponding to energy availability) deployed at 3203 m in the Pacific Ocean for 5 years. We use four fundamental energetic species-level functional traits—food source, trophic category, motility and tiering—to characterize species niches. Increases in energy on wood falls lead to increases in species richness. This higher species richness resulted from a substantial increase in mean niche overlap, suggesting that increases in energy may afford reduced competition.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

scholarly journals Holocene changes in African vegetation: tradeoff between climate and water availability

2014 ◽  
Vol 10 (2) ◽  
pp. 681-686 ◽  
Author(s):  
C. Hély ◽  
A.-M. Lézine ◽  
APD contributors
Keyword(s):  
West Africa ◽  
Water Availability ◽  
Regional Scale ◽  
Plant Distribution ◽  
Climate Conditions ◽  
Tropical Plants ◽  
Plant Migration ◽  
Spatio Temporal ◽  
The Individual ◽  
Instrumental Records

Abstract. Although past climate change is well documented in West Africa through instrumental records, modeling activities, and paleo-data, little is known about regional-scale ecosystem vulnerability and long-term impacts of climate on plant distribution and biodiversity. Here we use paleohydrological and paleobotanical data to discuss the relation between available surface water, monsoon rainfall and vegetation distribution in West Africa during the Holocene. The individual patterns of plant migration or community shifts in latitude are explained by differences among tolerance limits of species to rainfall amount and seasonality. Using the probability density function methodology, we show here that the widespread development of lakes, wetlands and rivers at the time of the "Green Sahara" played an additional role in forming a network of topographically defined water availability, allowing for tropical plants to migrate north from 15 to 24° N (reached ca. 9 cal ka BP). The analysis of the spatio–temporal changes in biodiversity, through both pollen occurrence and richness, shows that the core of the tropical rainbelt associated with the Intertropical Convergence Zone was centered at 15–20° N during the early Holocene wet period, with comparatively drier/more seasonal climate conditions south of 15° N.

scholarly journals Quantitative Trait Loci for Grain Yield and Adaptation of Durum Wheat (Triticum durumDesf.) Across a Wide Range of Water Availability

Genetics ◽  
2008 ◽  
Vol 178 (1) ◽  
pp. 489-511 ◽  
Author(s):  
Marco Maccaferri ◽  
Maria Corinna Sanguineti ◽  
Simona Corneti ◽  
José Luis Araus Ortega ◽  
Moncef Ben Salem ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Grain Yield ◽  
Durum Wheat ◽  
Water Availability ◽  
Quantitative Trait ◽  
Wide Range ◽  
Trait Loci

scholarly journals Leaf Traits of Trees in Tropical Dry Evergreen Forests of Peninsular India

Ecologies ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 268-284
Author(s):  
Muthulingam Udayakumar ◽  
Thangavel Sekar
Keyword(s):  
Negative Relationship ◽  
Leaf Traits ◽  
Functional Trait ◽  
Matter Content ◽  
Evergreen Forest ◽  
Leaf Life Span ◽  
Dry Matter Content ◽  
Evergreen Species ◽  
Peninsular India ◽  
Plant Functional Trait

A plant functional trait study was conducted to know the existing relationship between important leaf traits namely, specific leaf area (SLA), leaf dry matter content (LDMC), and leaf life span (LL) in tropical dry evergreen forest (TDEFs) of Peninsular India. Widely accepted methodologies were employed to record functional traits. The relationships between SLA and LDMC, LDMC and LL, and SLA and LL were measured. Pearson’s coefficient of correlation showed a significant negative relationship between SLA and LDMC, and SLA and LL, whereas a significant positive relationship was prevailed between LDMC and LL. The mean trait values (SLA, LDMC, and LL) of evergreens varied significantly from deciduous species. SLA had a closer relationship with LDMC than LL. Similarly, LL had a closer relationship with SLA than LDMC. Species with evergreen leaf habits dominated forest sites under study. Evergreen species dominate the study area with a high evergreen-deciduous ratio of 5.34:1. The S strategy score of trees indicated a relatively higher biomass allocation to persistent tissues. TDEFs occur in low elevation, semiarid environment, but with the combination of oligotrophic habitat, high temperature and longer dry season these forests were flourishing as a unique evergreen ecosystem in the drier environment. The relationships found between leaf traits were in concurrence with earlier findings. Trees of TDEFs survive on the poor-nutrient habitat with a low SLA, high LDMC, and LL. This study adds baseline data on key leaf traits to plant functional trait database of India.

scholarly journals Abundance and Sources of Atmospheric Halocarbons in the Eastern Mediterranean

2017 ◽  
Author(s):  
Fabian Schoenenberger ◽  
Stephan Henne ◽  
Matthias Hill ◽  
Martin K. Vollmer ◽  
Giorgos Kouvarakis ◽  
...  
Keyword(s):  
Western Europe ◽  
Atmospheric Transport ◽  
Eastern Mediterranean ◽  
Stratospheric Ozone ◽  
Regional Scale ◽  
Top Down ◽  
Inversion Domain ◽  
Hfc 134A ◽  
Wide Range ◽  
Hfc 152A

Abstract. A wide range of anthropogenic halocarbons is released to the atmosphere, contributing to stratospheric ozone depletion and global warming. Using measurements of atmospheric abundances for the estimation of halocarbon emissions on the global and regional scale has become an important top-down tool for emission validation in the recent past, but many populated and developing areas of the world are only poorly covered by the existing atmospheric halocarbon measurement network. Here we present six months of continuous halocarbon observations from Finokalia on the island of Crete in the Eastern Mediterranean. The gases measured are the hydrofluorocarbons (HFCs), HFC-134a (CH2FCF3), HFC-125 (CHF2CF3), HFC-152a (CH3CHF2) and HFC-143a (CH3CF3), and the hydrochlorofluorocarbons (HCFCs), HCFC-22 (CHClF2) and HCFC-142b (CH3CClF2). The Eastern Mediterranean is home to 250 million inhabitants, consisting of a number of developed and developing countries, for which different emission regulations exist under the Kyoto and Montreal Protocols. Regional emissions of halocarbons were estimated with Lagrangian atmospheric transport simulations and a Bayesian inverse modelling system, using measurements at Finokalia in conjunction with those from Advanced Global Atmospheric Gases Experiment (AGAGE) sites at Mace Head (Ireland), Jungfraujoch (Switzerland) and Monte Cimone (Italy). Measured peak mole fractions at Finokalia showed generally smaller amplitudes for HFCs than at the European AGAGE sites, except periodic peaks of HFC-152a, indicating strong upwind sources. Higher peak mole fractions were observed for HCFCs, suggesting continued emissions from nearby developing regions such as Egypt and the Middle East. For 2013, the Eastern Mediterranean inverse emission estimates for the four analysed HFCs and the two HCFCs were 14.7 (6.7–23.3) Tg CO2eq yr-1 and 9.7 (4.3–15.7) Tg CO2eq yr-1, respectively. These emissions contributed 17.3 % (7.9–27.4 %) and 53 % (23.5–86%) to the total inversion domain, which covers the Eastern Mediterranean as well as Central and Western Europe. Greek bottom-up HFC emissions reported to the UNFCCC were much smaller than our top-down estimates, whereas for Turkey our estimates agreed with UNFCCC-reported values for HFC-125 and HFC-143a, but were much and slightly smaller for HFC-134a and HFC-152a, respectively. Sensitivity estimates suggest an improvement of the a posteriori emission estimates, i.e. a reduction of the uncertainties by 40–80 %, compared to an inversion using only the existing Central European AGAGE observations.

scholarly journals Selection and integration of Earth Observation-based data for an operational disease forecasting system

2020 ◽  
Author(s):  
Eleanor A Ainscoe ◽  
Barbara Hofmann ◽  
Felipe Colon ◽  
Iacopo Ferrario ◽  
Quillon Harpham ◽  
...  
Keyword(s):  
Land Cover ◽  
Dengue Fever ◽  
Water Availability ◽  
Land Surface ◽  
Warning System ◽  
Earth Observation ◽  
Disease Forecasting ◽  
Current Increase ◽  
Disease Case ◽  
Wide Range

&lt;p&gt;The current increase in the volume and quality of Earth Observation (EO) data being collected by satellites offers the potential to contribute to applications across a wide range of scientific domains. It is well established that there are correlations between characteristics that can be derived from EO satellite data, such as land surface temperature or land cover, and the incidence of some diseases. Thanks to the reliable frequent acquisition and rapid distribution of EO data it is now possible for this field to progress from using EO in retrospective analyses of historical disease case counts to using it in operational forecasting systems.&lt;/p&gt;&lt;p&gt;However, bringing together EO-based and non-EO-based datasets, as is required for disease forecasting and many other fields, requires carefully designed data selection, formatting and integration processes. Similarly, it requires careful communication between collaborators to ensure that the priorities of that design process match the requirements of the application.&lt;/p&gt;&lt;p&gt;Here we will present work from the D-MOSS (Dengue forecasting MOdel Satellite-based System) project. D-MOSS is a dengue fever early warning system for South and South East Asia that will allow public health authorities to identify areas at high risk of disease epidemics before an outbreak occurs in order to target resources to reduce spreading of epidemics and improve disease control. The D-MOSS system uses EO, meteorological and seasonal weather forecast data, combined with disease statistics and static layers such as land cover, as the inputs into a dengue fever model and a water availability model. Water availability directly impacts dengue epidemics due to the provision of mosquito breeding sites. The datasets are regularly updated with the latest data and run through the models to produce a new monthly forecast. For this we have designed a system to reliably feed standardised data to the models. The project has involved a close collaboration between remote sensing scientists, geospatial scientists, hydrologists and disease modelling experts. We will discuss our approach to the selection of data sources, data source quality assessment, and design of a processing and ingestion system to produce analysis-ready data for input to the disease and water availability models.&lt;/p&gt;

scholarly journals Тематическое исследование всемирного наследия Центральной Азии Primary tabs

2021 ◽  
Author(s):  
Hervé Lethier
Keyword(s):  
Central Asia ◽  
Regional Scale ◽  
World Heritage ◽  
Initial Assessment ◽  
World Heritage List ◽  
Wide Range ◽  
The World ◽  
Level Of Knowledge ◽  
Primary Focus ◽  
Terrestrial Biodiversity

The World Heritage thematic study for Central Asia has been produced as a contribution to supporting the implementation of the World Heritage Convention in Central Asia. It provides a response to a Decision of the World Heritage Committee in order to identify outstanding areas with potential for future nomination to the World Heritage List with primary focus on criteria (ix) and (x) at the regional scale. The approach applied in this study, focusing on criteria (ix) and (x), follows that from the 2013 study on terrestrial biodiversity and the World Heritage List. Criteria (ix) and (x) are clearly the primary ones for recognition of extant biodiversity values, and they have been applied to a wide range of biodiversity features, including ecosystems, species, and ecological and/or biological processes. Although this study is an initial assessment, most areas and sites recommended here have appeared repeatedly as being of particular interest for biodiversity conservation during the work process, whether through literature analysis or in discussions with experts and specialists. The recommendations reflect the current level of knowledge that should be strengthened in the future, to ensure that the identified areas and sites are well supported with the necessary data and empirical evidence to address the requirements of the Operational Guidelines.

scholarly journals Resource partitioning and ecomorphological variation in two syntopic species of Lebiasinidae (Characiformes) in an Amazonian stream

2016 ◽  
Vol 46 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Nathália Carina dos Santos SILVA ◽  
Aluízio José Lopes da COSTA ◽  
José LOUVISE ◽  
Bruno Eleres SOARES ◽  
Vanessa Cristine e Souza REIS ◽  
...  
Keyword(s):  
Resource Partitioning ◽  
Trophic Ecology ◽  
Species Coexistence ◽  
Stomach Contents ◽  
Relative Length ◽  
Niche Overlap ◽  
The Body ◽  
Feeding Strategies ◽  
Relative Depth ◽  
Feeding Niche

ABSTRACTResource partitioning is important for species coexistence. Species with similar ecomorphology are potential competitors, especially when phylogenetically close, due to niche conservatism. The aim of this study was to investigate the resource partitioning among populations of two species of lebiasinids (Copella nigrofasciata and Pyrrhulina aff. brevis) that co-occur in a first-order Amazonian stream, analyzing the trophic ecology, feeding strategies and ecomorphological attributes related to the use of food and space by these species. Fish were captured in May and September 2010. The stomach contents of 60 individuals were analyzed and quantified volumetrically to characterize the feeding ecology of both species. Eleven morphological attributes were measured in 20 specimens and combined in nine ecomorphological indices. Both species had an omnivorous-invertivorous diet and consumed predominantly allochthonous items. Both showed a tendency to a generalist diet, but intrapopulational variation in resource use was also detected. Overall feeding niche overlap was high, but differed between seasons: low during the rainy season and high in the dry season. In the latter, the food niche overlap was asymmetric because C. nigrofasciata consumed several prey of P. aff. brevis, which reduced its food spectrum. The ecomorphological analysis suggests that C. nigrofasciatahas greater swimming capacity (greater relative length of caudal peduncle) than P. aff. brevis, which has greater maneuverability and tendency to inhabit lentic environments (greater relative depth of the body). Our results demonstrate that these species have similar trophic ecology and suggest a spatial segregation, given by morphological differences related to locomotion and occupation of habitat, favoring their coexistence.

scholarly journals Editorial of Special Issue “Advances in Groundwater Flow and Solute Transport: Pushing the Hidden Boundary”

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457
Author(s):  
Hongbin Zhan ◽  
Quanrong Wang ◽  
Zhang Wen
Keyword(s):  
Numerical Methods ◽  
Groundwater Flow ◽  
Solute Transport ◽  
Vadose Zone ◽  
Regional Scale ◽  
Chemical Transport ◽  
Low Permeability ◽  
Special Issue ◽  
Flow And Transport ◽  
Wide Range

The theme of this special issue is to explore the new territories beyond conventional subsurface flow and transport theories. We have selected 12 articles in this special issue and these articles cover a wide range of problems including (1) Non-Fickian chemical transport in various environments; (2) Non-Darcian flow; (3) Flow and transport in low-permeability media; (4) Vadose zone process; (5) Regional scale groundwater flow and groundwater-surface interaction; (6) Innovative numerical methods. The major contributions of these papers are summarized in this editorial.

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