scholarly journals Annoying neighbors: Multi-scale distribution determinants of two sympatric sibling species of birds

2015 ◽  
Vol 61 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Alban Guillaumet ◽  
Guillaume Leotard
Keyword(s):  
Sibling Species ◽  
Species Distribution ◽  
Spatial Scales ◽  
Sand Dunes ◽  
Regional Scale ◽  
Local Scale ◽  
Range Limit ◽  
White Sand ◽  
Ecological Predictors ◽  
Moroccan Coast

Abstract We tested the role of interspecific competition in driving species distribution at multiple spatial scales using two sibling species of Galerida larks (G. cristata and G. theklae) in Morocco (sympatry), Balearic islands (G. theklae only) and Israel (G. cristata only). We first investigated regional-scale determinants by contrasting allopatric versus sympatric patterns in five distinct habitat types. We next focused on a single habitat used by both species, the coastal sand dunes. Dune quadrats were established along the Moroccan coast and completed by a quadrat in the nearest distinct landscape habitat. Poisson regressions were used to model Galerida counts together with ecological predictors as concerns the climate, topography, vegetation structure and soil gra-nulometry. At the local scale, both species preferred grey dunes over white sand dunes, and both were negatively affected by the abundance of the congeneric species in the dune. However, we found that G. theklae tended to replace G. cristata in more arid sand dunes, even if the transition was not strictly clinal. Instead, the transition occurred when the surrounding landscape changed from coastal wetlands to bathas (grasslands with shrubs), highlighting the importance of habitat composition at the landscape scale. The fact that G. cristata used bathas in allopatry, but not in sympatry, suggested that the competitive environment contributed to determine sand dune occupancy. We suggest that landscape-level effects may be pivotal in explaining species distribution not only at the local scale, by affecting the pool of potential immigrants, but also at the regional scale, by contributing to species’ range limit.

scholarly journals Exploring the Interplay Between Local and Regional Drivers of Distribution of a Subterranean Organism

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 119 ◽  
Author(s):  
Stefano Mammola ◽  
Shlomi Aharon ◽  
Merav Seifan ◽  
Yael Lubin ◽  
Efrat Gavish-Regev
Keyword(s):  
Species Distribution ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Regional Scale ◽  
Regional Distribution ◽  
Ecological Factors ◽  
Local Scale ◽  
Model Systems ◽  
Mean Annual Temperature ◽  
Distribution Models

Caves are excellent model systems to study the effects of abiotic factors on species distributions due to their selective conditions. Different ecological factors have been shown to affect species distribution depending on the scale of analysis, whether regional or local. The interplay between local and regional factors in explaining the spatial distribution of cave-dwelling organisms is poorly understood. Using the troglophilic subterranean spider Artema nephilit (Araneae: Pholcidae) as a model organism, we investigated whether similar environmental predictors drive the species distribution at these two spatial scales. At the local scale, we monitored the abundance of the spiders and measured relevant environmental features in 33 caves along the Jordan Rift Valley. We then extended the analysis to a regional scale, investigating the drivers of the distribution using species distribution models. We found that similar ecological factors determined the distribution at both local and regional scales for A. nephilit. At a local scale, the species was found to preferentially occupy the outermost, illuminated, and warmer sectors of caves. Similarly, mean annual temperature, annual temperature range, and solar radiation were the most important drivers of its regional distribution. By investigating these two spatial scales simultaneously, we showed that it was possible to achieve an in-depth understanding of the environmental conditions that governs subterranean species distribution.

scholarly journals Local-scale Arctic tundra heterogeneity affects regional-scale carbon dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
M. J. Lara ◽  
A. D. McGuire ◽  
E. S. Euskirchen ◽  
H. Genet ◽  
S. Yi ◽  
...  
Keyword(s):  
Spatial Scale ◽  
Spatial Scales ◽  
Regional Scale ◽  
Hierarchical Cluster ◽  
Carbon Dynamics ◽  
Local Scale ◽  
Reduced Representation ◽  
Soil Carbon Dynamics ◽  
Biogeochemical Models ◽  
Northern Alaska

Abstract In northern Alaska nearly 65% of the terrestrial surface is composed of polygonal ground, where geomorphic tundra landforms disproportionately influence carbon and nutrient cycling over fine spatial scales. Process-based biogeochemical models used for local to Pan-Arctic projections of ecological responses to climate change typically operate at coarse-scales (1km2–0.5°) at which fine-scale (<1km2) tundra heterogeneity is often aggregated to the dominant land cover unit. Here, we evaluate the importance of tundra heterogeneity for representing soil carbon dynamics at fine to coarse spatial scales. We leveraged the legacy of data collected near Utqiaġvik, Alaska between 1973 and 2016 for model initiation, parameterization, and validation. Simulation uncertainty increased with a reduced representation of tundra heterogeneity and coarsening of spatial scale. Hierarchical cluster analysis of an ensemble of 21st-century simulations reveals that a minimum of two tundra landforms (dry and wet) and a maximum of 4km2 spatial scale is necessary for minimizing uncertainties (<10%) in regional to Pan-Arctic modeling applications.

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.

The modulating role of traits on the biogeographic dynamics of chondrichthyans from the Neogene to the present

Paleobiology ◽  
2018 ◽  
Vol 44 (2) ◽  
pp. 251-262 ◽  
Author(s):  
Jaime A. Villafaña ◽  
Marcelo M. Rivadeneira
Keyword(s):  
Life History ◽  
Spatial Scales ◽  
Regional Scale ◽  
Local Scale ◽  
Range Shifts ◽  
Similar Proportion ◽  
Random Forest Models ◽  
Body Sizes ◽  
Exogenous Factors

AbstractThe environmental transformations that occurred during the Neogene had profound effects on spatiotemporal biodiversity patterns, yet the modulating role of traits (i.e., physiological, ecological, and life-history traits) remains little understood. We tested this idea using the Neogene fossil record of chondrichthyans along the temperate Pacific coast of South America (TPSA). Information for georeferenced occurrences and ecological and life-history information of 38 chondrichthyan fossil genera in 42 Neogene sites was collected. Global georeferenced records were used to estimate present-day biogeographic distributions of the genera and to characterize the range of oceanographic conditions in which each genus lives as a proxy of their realized niche. Biogeographic range shifts (Neogene–present) were evaluated at regional and local scales. The role of traits as drivers of different range dynamics was evaluated using random forest models. The magnitude and direction of biogeographic range shifts were different at both spatial scales. At a regional scale, 34% of genera contracted their ranges, disappearing from the TPSA. At a local scale, a similar proportion of genera expanded and contracted their southern endpoints of distribution. The models showed a high precision at both spatial scales of analyses, but the relative importance of predictor variables differed. At a regional scale, disappearing genera tended to have a higher tolerance to salinity, lower sea surface temperature (SST) range, and smaller body sizes. At a local scale, genera contracting their ranges tended to live at greater depths, tolerate lower levels of primary productivity, and show a reduced tolerance to higher and lower SST ranges. The magnitude and direction of the changes in the range distribution were scale dependent and variable across the genera. Hence, multiple environmental exogenous factors interacted with taxon traits during the Neogene, creating a mosaic of biogeographic dynamics.

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.

Tree-ring evidence extends the historic northern range limit of severe defoliation by insects in the aspen stands of western Quebec, Canada

2008 ◽  
Vol 38 (9) ◽  
pp. 2535-2544 ◽  
Author(s):  
Jian-Guo Huang ◽  
Jacques Tardif ◽  
Bernhard Denneler ◽  
Yves Bergeron ◽  
Frank Berninger
Keyword(s):  
Tree Ring ◽  
Populus Tremuloides ◽  
Host Species ◽  
Spatial Scales ◽  
Regional Scale ◽  
Trembling Aspen ◽  
Range Limit ◽  
Insect Outbreaks ◽  
Northern Latitudes ◽  
Northern Range Limit

A dendrochronological reconstruction of insect outbreaks was conducted along a latitudinal gradient from 46°N to 54°N in the boreal forest of western Quebec, Canada. Tree-ring chronologies of the host species, trembling aspen ( Populus tremuloides Michx.), were constructed to identify periods of severe defoliation and comparisons were made with tree-ring chronologies of nonhost species. In addition, the frequency of white and narrow rings was used to further confirm the occurrence of insect outbreaks at these latitudes. Some major outbreaks occurred in relatively close synchrony at the regional scale, but the initiation year, intensity, and extent of the outbreaks varied spatially. For example, the 1950s outbreaks were observed from 1951 to 1952 at 46°N, from 1953 to 1954 at 47°N, and from 1954 to 1956 at 48°N. Other major outbreaks like the 1964 and 1980 outbreaks were fairly well synchronized at northern latitudes. The observed outbreaks in trembling aspen stands at 54°N also provided clear evidence that severe insect defoliation occurs much further north than the currently reported range limit, that is, between 49°N and 51°N, of the most important trembling aspen defoliator, the forest tent caterpillar ( Malacosoma disstria Hubner). Our study demonstrated that careful identification of white rings in host species can provide valid information allowing the expansion of the forestry insect inventory database both at temporal and spatial scales.

scholarly journals Setting the Flow Accumulation Threshold Based on Environmental and Morphologic Features to Extract River Networks from Digital Elevation Models

2021 ◽  
Vol 10 (3) ◽  
pp. 186
Author(s):  
HuiHui Zhang ◽  
Hugo A. Loáiciga ◽  
LuWei Feng ◽  
Jing He ◽  
QingYun Du
Keyword(s):  
Spatial Scales ◽  
Digital Elevation Models ◽  
Regional Scale ◽  
Drainage Density ◽  
River Network ◽  
Landscape Patterns ◽  
Estimation Methods ◽  
River Networks ◽  
Flow Accumulation ◽  
Digital Elevation

Determining the flow accumulation threshold (FAT) is a key task in the extraction of river networks from digital elevation models (DEMs). Several methods have been developed to extract river networks from Digital Elevation Models. However, few studies have considered the geomorphologic complexity in the FAT estimation and river network extraction. Recent studies estimated influencing factors’ impacts on the river length or drainage density without considering anthropogenic impacts and landscape patterns. This study contributes two FAT estimation methods. The first method explores the statistical association between FAT and 47 tentative explanatory factors. Specifically, multi-source data, including meteorologic, vegetation, anthropogenic, landscape, lithology, and topologic characteristics are incorporated into a drainage density-FAT model in basins with complex topographic and environmental characteristics. Non-negative matrix factorization (NMF) was employed to evaluate the factors’ predictive performance. The second method exploits fractal geometry theory to estimate the FAT at the regional scale, that is, in basins whose large areal extent precludes the use of basin-wide representative regression predictors. This paper’s methodology is applied to data acquired for Hubei and Qinghai Provinces, China, from 2001 through 2018 and systematically tested with visual and statistical criteria. Our results reveal key local features useful for river network extraction within the context of complex geomorphologic characteristics at relatively small spatial scales and establish the importance of properly choosing explanatory geomorphologic characteristics in river network extraction. The multifractal method exhibits more accurate extracting results than the box-counting method at the regional scale.

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

scholarly journals Large but decreasing effect of ozone on the European carbon sink

2018 ◽  
Vol 15 (13) ◽  
pp. 4245-4269 ◽  
Author(s):  
Rebecca J. Oliver ◽  
Lina M. Mercado ◽  
Stephen Sitch ◽  
David Simpson ◽  
Belinda E. Medlyn ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Primary Productivity ◽  
Carbon Sink ◽  
Spatial Scales ◽  
Stomatal Closure ◽  
Regional Scale ◽  
Surface Model ◽  
Background Concentrations ◽  
Tropospheric O3 ◽  
The Impact

Abstract. The capacity of the terrestrial biosphere to sequester carbon and mitigate climate change is governed by the ability of vegetation to remove emissions of CO2 through photosynthesis. Tropospheric O3, a globally abundant and potent greenhouse gas, is, however, known to damage plants, causing reductions in primary productivity. Despite emission control policies across Europe, background concentrations of tropospheric O3 have risen significantly over the last decades due to hemispheric-scale increases in O3 and its precursors. Therefore, plants are exposed to increasing background concentrations, at levels currently causing chronic damage. Studying the impact of O3 on European vegetation at the regional scale is important for gaining greater understanding of the impact of O3 on the land carbon sink at large spatial scales. In this work we take a regional approach and update the JULES land surface model using new measurements specifically for European vegetation. Given the importance of stomatal conductance in determining the flux of O3 into plants, we implement an alternative stomatal closure parameterisation and account for diurnal variations in O3 concentration in our simulations. We conduct our analysis specifically for the European region to quantify the impact of the interactive effects of tropospheric O3 and CO2 on gross primary productivity (GPP) and land carbon storage across Europe. A factorial set of model experiments showed that tropospheric O3 can suppress terrestrial carbon uptake across Europe over the period 1901 to 2050. By 2050, simulated GPP was reduced by 4 to 9 % due to plant O3 damage and land carbon storage was reduced by 3 to 7 %. The combined physiological effects of elevated future CO2 (acting to reduce stomatal opening) and reductions in O3 concentrations resulted in reduced O3 damage in the future. This alleviation of O3 damage by CO2-induced stomatal closure was around 1 to 2 % for both land carbon and GPP, depending on plant sensitivity to O3. Reduced land carbon storage resulted from diminished soil carbon stocks consistent with the reduction in GPP. Regional variations are identified with larger impacts shown for temperate Europe (GPP reduced by 10 to 20 %) compared to boreal regions (GPP reduced by 2 to 8 %). These results highlight that O3 damage needs to be considered when predicting GPP and land carbon, and that the effects of O3 on plant physiology need to be considered in regional land carbon cycle assessments.

scholarly journals Are Distribution Patterns Correlated with Plant Traits?

2021 ◽  
Author(s):  
◽  
Benjamin Magana-Rodriguez
Keyword(s):  
Life History ◽  
Leaf Area ◽  
Spatial Patterns ◽  
Life History Traits ◽  
Multiple Scales ◽  
Spatial Scales ◽  
Regional Scale ◽  
Distribution Patterns ◽  
Spatial Arrangement ◽  
Scaling Relationship

<p>The current crisis in loss of biodiversity requires rapid action. Knowledge of species' distribution patterns across scales is of high importance in determining their current status. However, species display many different distribution patterns on multiple scales. A positive relationship between regional (broad-scale) distribution and local abundance (fine-scale) of species is almost a constant pattern in macroecology. Nevertheless interspecific relationships typically contain much scatter. For example, species that possess high local abundance and narrow ranges, or species that are widespread, but locally rare. One way to describe these spatial features of distribution patterns is by analysing the scaling properties of occupancy (e.g., aggregation) in combination with knowledge of the processes that are generating the specific spatial pattern (e.g., reproduction, dispersal, and colonisation). The main goal of my research was to investigate if distribution patterns correlate with plant life-history traits across multiple scales. First, I compared the performance of five empirical models for their ability to describe the scaling relationship of occupancy in two datasets from Molesworth Station, New Zealand. Secondly, I analysed the association between spatial patterns and life history traits at two spatial scales in an assemblage of 46 grassland species in Molesworth Station. The spatial arrangement was quantified using the parameter k from the Negative Binomial Distribution (NBD). Finally, I investigated the same association between spatial patterns and life-history traits across local, regional and national scales, focusing in one of the most diverse families of plant species in New Zealand, the Veronica sect. Hebe (Plantaginaceae). The spatial arrangement was investigated using the mass fractal dimension. Cross-species correlations and phylogenetically independent contrasts were used to investigate the relationships between plant life-history traits and spatial patterns on both data bases. There was no superior occupancy-area model overall for describing the scaling relationship, however the results showed that a variety of occupancy-area models can be fit to different data sets at diverse spatial scales using nonlinear regression. Additionally, here I showed that it is possible to deduce and extrapolate information on occupancy at fine scales from coarse-scale data. For the 46 plantassemblage in Molesworth Station, Specific leaf area (SLA) exhibits a positive association with aggregation in cross-species analysis, while leaf area showed a negative association, and dispersule mass a positive correlation with degree of aggregation in phylogenetic contrast analysis at a local-scale (20 × 20 m resolution). Plant height was the only life-history trait that was associated with degree of aggregation at a regional-scale (100 × 60 mresolution). For the Veronica sect. Hebe dataset, leaf area showed a positive correlation with aggregation while specific leaf area showed a negative correlation with aggregation at a fine local-scale (2.5-60 m resolution). Inflorescence length, breeding system and leaf area showed a negative correlation with degree of aggregation at a regional-scale (2.5-20 km resolution). Height was positively associated with aggregation at national-scale (20-100 km resolution). Although life-history traits showed low predictive ability in explaining aggregation throughout this thesis, there was a general pattern about which processes and traits were important at different scales. At local scales traits related to dispersal and completion such as SLA , leaf area, dispersule mass and the presence of structures in seeds for dispersal, were important; while at regional scales traits related to reproduction such as breeding system, inflorescence length and traits related to dispersal (seed mass) were significant. At national scales only plant height was important in predicting aggregation. Here, it was illustrated how the parameters of these scaling models capture an important aspect of spatial pattern that can be related to other macroecological relationships and the life-history traits of species. This study shows that when several scales of analysis are considered, we can improve our understanding about the factors that are related to species' distribution patterns.</p>

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