Shrub colonization regulates δ13C enrichment between soil and vegetation in deserts by affecting edaphic variables

Oat, Avena sativa, is an important crop traditionally grown in cool-temperate regions. However, its cultivated area in the Mediterranean rim steadily increased during the last 20 years due to its good adaptation to a wide range of soils. Nevertheless, under Mediterranean cultivation conditions, oats have to face high temperatures and drought episodes that reduce its yield as compared with northern regions. Therefore, oat crop needs to be improved for adaptation to Mediterranean environments. In this work, we investigated the influence of climatic and edaphic variables on a collection of 709 Mediterranean landraces and cultivars growing under Mediterranean conditions. We performed genotype–environment interaction analysis using heritability-adjusted genotype plus genotype–environment biplot analyses to determine the best performing accessions. Further, their local adaptation to different environmental variables and the partial contribution of climate and edaphic factors to the different agronomic traits was determined through canonical correspondence, redundancy analysis, and variation partitioning. Here, we show that northern bred elite cultivars were not among the best performing accessions in Mediterranean environments, with several landraces outyielding these. While all the best performing cultivars had early flowering, this was not the case for all the best performing landraces, which showed different patterns of adaption to Mediterranean agroclimatic conditions. Thus, higher yielding landraces showed adaptation to moderate to low levels of rain during pre- and post-flowering periods and moderate to high temperature and radiation during post-flowering period. This analysis also highlights landraces adapted to more extreme environmental conditions. The study allowed the selection of oat genotypes adapted to different climate and edaphic factors, reducing undesired effect of environmental variables on agronomic traits and highlights the usefulness of variation partitioning for selecting genotypes adapted to specific climate and edaphic conditions.

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Flooding effects on grassland species composition in the Azul creek basin, Argentina

The Rangeland Journal ◽

10.1071/rj16034 ◽

2017 ◽

Vol 39 (3) ◽

pp. 245 ◽

Cited By ~ 2

Author(s):

Ilda Entraigas ◽

Natalia Vercelli ◽

Guadalupe Ares ◽

Marcelo Varni ◽

Sofía Zeme

Keyword(s):

Land Surface ◽

Digital Terrain Model ◽

Floristic Composition ◽

Point Of View ◽

Buenos Aires Province ◽

Grassland Species ◽

Terrain Model ◽

Shallow Wells ◽

Edaphic Variables ◽

Surface And Groundwater

From a hydrological point of view, the characteristic of the water behaviour in catchments so depressed as the Azul creek basin (centre of Buenos Aires province, Argentina) is water accumulation above the land surface. Thus, water on the ground does not have a single runoff direction, but moves in a disorderly, indefinite and unpredictable way. Considering that periodic floods are a typical disturbance of the region, the objective of this study is to analyse, under field conditions, the transformative effect of prolonged flooding on floristic composition, taking into account the different vegetation patches and their relative position over the relief, the chemical characteristics and the groundwater fluctuation, and some edaphic properties in each site. Vegetation samplings were performed during three consecutive springs, when the grassland was on different hydrological conditions due to very different rainfall precedent histories. A digital terrain model of the study area was built and a flow accumulation map was created from it. Pits were dug to describe edaphic variables and shallow wells were drilled for monitoring the groundwater characteristics. Flooding, in relation with surface and groundwater dynamics and soil characteristics, is the factor that determines and promotes the differentiation among sites that are relatively close, contiguous and even topographically in almost identical positions. So, some patches of vegetation get their differentiation through the limiting conditions of their soils, while others receive greater influence from the hydrodynamics to which they are subject. Thus, in this study it becomes evident how certain stands are floristically homogenised or differentiated over time according to their flooding conditions and, hence, according to the area from which they receive surface and groundwater flow. Also, results corroborate the way the water regime determines the structure and heterogeneity of plant communities in such environments.

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Climate Defined but Not Soil-restricted: The Distribution of a Neotropical tree through Space and Time

10.21203/rs.3.rs-333060/v1 ◽

2021 ◽

Author(s):

Facundo Alvarez ◽

Paulo S Morandi ◽

Ben Hur Marimon-Junior ◽

Reginal Exavier ◽

Igor Araújo ◽

...

Keyword(s):

Spatial Distribution ◽

Environmental Variables ◽

Distribution Patterns ◽

Distribution Models ◽

Climatic Fluctuations ◽

Space And Time ◽

Predictive Variables ◽

Soil Variables ◽

Neotropical Tree ◽

Edaphic Variables

Abstract AimsBrosimum rubescens, a tree species with a Neotropical distribution, can achieve local monodominance in Southern Amazonia forests. Understanding how and why this species varies across space and time is important because the monodominance of some species alters ecosystems complexity. Here we evaluate the fundamental ecological niche of B. rubescens by species distribution models (SDM), combining predictive environmental variables with occurrence points. We specifically aim to 1) determine how the spatial distribution patterns of B. rubescens vary with different environmental predictive variables, and 2) evaluate the temporal and spatial persistence of B. rubescens in the Neotropics. MethodsTo generate the SDMs, the predictive environmental variables were incorporated as main components of climatic, hydric and soil variables. ResultsAll algorithms show higher performance in spatial predictions for hydric variables and for the combination of climatic, hydric and edaphic variables. We identified that the potential niches of B. rubescens seem to be defined by climatic fluctuations, with the edaphic conditions being predictive variables that are not restrictive of their presence on the evaluated spatial scale. From the LMG (Last Glacial Maximum) to the present, the species seems to have increased its spatial amplitude; however, from the present to the future, predictions suggest that B. rubescens will experience a considerable loss of its range. ConclusionsOur findings show the independent and combined effects of different environmental variables, allowing us to identify which limit or facilitate the spatial distribution of B. rubescens. We corroborate the spatial persistence and geographical fidelity of the species' spatial patterns over time.

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Environmental structure and relationships in the setting of natural water springs in a Lower Highland Seasonal Forest in Brazilian South

Ciência Rural ◽

10.1590/0103-8478cr20170857 ◽

2018 ◽

Vol 48 (11) ◽

Author(s):

Paulo Alfonso Floss ◽

Solon Jonas Longhi ◽

Malcon do Prado Costa ◽

Elzira Cecília Serafini Floss

Keyword(s):

Natural Water ◽

Riparian Forest ◽

Forest Recovery ◽

Physical Analysis ◽

Soil Variables ◽

Environmental Structure ◽

Calcium Magnesium ◽

Initial Recovery ◽

Edaphic Variables ◽

Water Springs

ABSTRACT: The aim of this research was to characterize an environmental structure in the setting of tree natural water springs in a Lower Highland Seasonal Forest, and to verify the relationship between community demography and soil variables as subsidies for species identification in riparian forest recovery programs in similar environments. The research was carried out in the National Forest of Chapecó, located in the west of the state of Santa Catarina in the southern region of Brazil. For this, three water springs were demarcated, where 26 plots of 200m² in each were allocated. All individuals with diameter at 1.30m of soil height ≥5.0cm were measured. Soil samples (0 to 20cm depth) were collected in the plots for chemical and physical analysis. To relate the abundance of the species to the edaphic variables, the Canonical Correspondence Analysis (CCA) was used. A total of 76 species belonging to 64 genera of 36 botanical families were reported in the study area. The families Fabaceae and Myrtaceae presented greater floristic richness. The edaphic variables that most influenced the distribution of the species were aluminum saturation and calcium, magnesium and potassium contents. Specific groups of indicator species were formed for each water spring. The species designated as generalists are the most recommended for the initial filling and recovery of degraded springs. Further rare species and with low density must be included after the initial recovery to increase diversity.

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Maxent Data Mining Technique and Its Comparison with a Bivariate Statistical Model for Predicting the Potential Distribution of Astragalus Fasciculifolius Boiss. in Fars, Iran

Sustainability ◽

10.3390/su11123452 ◽

2019 ◽

Vol 11 (12) ◽

pp. 3452 ◽

Cited By ~ 6

Author(s):

Marjaneh Mousazade ◽

Gholamabbas Ghanbarian ◽

Hamid Reza Pourghasemi ◽

Roja Safaeian ◽

Artemi Cerdà

Keyword(s):

Data Mining ◽

Statistical Model ◽

Habitat Suitability ◽

Environmental Variables ◽

Potential Distribution ◽

Data Mining Technique ◽

Mining Technique ◽

Suitability Map ◽

Habitat Suitability Map ◽

Edaphic Variables

The identification of geographical distribution of a plant species is crucial for understanding the importance of environmental variables affecting plant habitat. In the present study, the spatial potential distribution of Astragalus fasciculifolius Boiss. as a key specie was mapped using maximum entropy (Maxent) as data mining technique and bivariate statistical model (FR: frequency ratio) in marl soils of southern Zagros, Iran. The A. fasciculifolius locations were identified and recorded by intensive field campaigns. Then, localities points were randomly split into a 70% training dataset and 30% for validation. Two climatic, four topographic, and eight edaphic variables were used to model the A. fasciculifolius distribution and its habitat potential. Maps of environmental variables were generated using Geographic Information System (GIS). Next, the habitat suitability index (HSI) maps were produced and classified by means of Maxent and FR approaches. Finally, the area under the receiver operating characteristic (AUC-ROC) curve was used to compare the performance of maps produced by Maxent and FR models. The interpretation of environmental variables revealed that the climatic and topographic parameters had less impact compared to edaphic variables in habitat distribution of A. fasciculifolius. The results showed that bulk density, nitrogen, acidity (pH), sand, and electrical conductivity (EC) of soil are the most significant variables that affect distribution of A. fasciculifolius. The validation of results showed that AUC values of Maxent and FR models are 0.83 and 0.76, respectively. The habitat suitability map by the better model (Maxent) showed that areas with high and very high suitable classes cover approximately 22% of the study area. Generally, the habitat suitability map produced using Maxent model could provide important information for conservation planning and a reclamation project of the degraded habitat of intended plant species. The distribution of the plants identifies the water, soil, and nutrient resources and affects the fauna distribution, and this is why it is relevant to research and to understand the plant distribution to properly improve the management and to achieve a sustainable management.

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Silvicultural strategies for adapting planted forests to climate change: from theory to practice

Journal of Forest Science ◽

10.17221/105/2011-jfs ◽

2012 ◽

Vol 58 (No. 6) ◽

pp. 265-277 ◽

Cited By ~ 10

Author(s):

W.L. Mason ◽

M. Petr ◽

S. Bathgate

Keyword(s):

Climate Change ◽

Sitka Spruce ◽

Site Classification ◽

Planted Forests ◽

Mixed Stands ◽

Actual Performance ◽

First Case ◽

Long Term Experiment ◽

Small Change ◽

Edaphic Variables

Adapting forests to climate change involves silvicultural measures such as use of a range of species and the fostering of mixed stands. We tested these in a Sitka spruce forest in southern Scotland, employing the Ecological Site Classification to match suitability of 24 species to six climatic and edaphic variables under values of accumulated temperature and moisture deficit projected for a medium emissions scenario for the present century. Both median and 90<sup>th</sup> percentile values were contrasted. In the first case there was a small change in species suitability with Sitka spruce, noble fir, downy birch, sycamore and aspen being the most suitable species. When the 90<sup>th</sup> percentile values were employed, the suitability of Sitka spruce and similar conifers had declined by the 2050’s due to soil moisture deficits. The actual performance of a range of species in a long-term experiment on a similar, warmer site showed several productive conifers including Sitka spruce that maintained reasonable growth when planted in mixture. Mixed plots were developing into pure stands of the most productive species. Species diversification was the most practical adaptation measure for this forest and should concentrate on areas of the greatest risk like south-facing slopes with free-draining soils.  

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Topographic and edaphic effects on the distribution of terrestrially reproducing anurans in Central Amazonia: mesoscale spatial patterns

Journal of Tropical Ecology ◽

10.1017/s0266467407004269 ◽

2007 ◽

Vol 23 (5) ◽

pp. 539-547 ◽

Cited By ~ 43

Author(s):

Marcelo Menin ◽

Albertina P. Lima ◽

William E. Magnusson ◽

Fabiano Waldez

Keyword(s):

Leaf Litter ◽

Environmental Gradients ◽

Free Water ◽

Clay Content ◽

Soil Characteristics ◽

Environmental Predictors ◽

Anuran Species ◽

Habitat Variation ◽

Central Amazonia ◽

Edaphic Variables

Many studies suggest that edaphic variables are major determinants of frog distributions. However, leaf-litter depth and soil characteristics are influenced by distance from streams, so the apparent relationship between edaphic characteristics and species distributions could be an artefact of the dependence of species on free water for reproduction. Therefore, we investigated the effect of edaphic variables on the mesoscale distribution of frog species not dependent on free water for reproduction. We evaluated the effects of soil texture, pH, slope, number of trees and leaf-litter volume on the distribution of nine terrestrially reproducing anuran species in the Reserva Ducke, a 100-km2 terra firme forest preserve in central Amazonia. Diurnal and nocturnal assemblages of anuran species were sampled in 72 plots systematically distributed across the reserve. We sampled the diurnal anuran assemblage by visual encounter in 250 × 1-m plots and the nocturnal assemblage in 250 × 20-m plots using both auditory and visual surveys. The majority of terrestrially breeding anuran species were influenced by topographic and/or edaphic variables, such as slope, soil clay content and pH. However, responses to environmental predictors differed among species. Most species occurred throughout all environmental gradients and relationships with soil characteristics were subtle, indicating that these species occur in the majority of habitats in Reserva Ducke. The results of this study indicate that terrestrially breeding frogs are habitat generalists that show little mesoscale beta diversity associated with habitat variation.

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