scholarly journals MAT drives the variation in maximum potential species richness and frost organizes the residual variation

2019 ◽  
Author(s):  
Ricardo A. Segovia
Keyword(s):  
Species Richness ◽  
Upper Bound ◽  
Large Scale ◽  
Explanatory Power ◽  
Mean Annual Temperature ◽  
Natural Logarithm ◽  
Residual Variation ◽  
Limited Support ◽  
Main Driver ◽  
The Relationship

AbstractThe kinetic hypothesis of biodiversity proposes that Mean Annual Temperature (MAT) is the main driver of variation in species richness, given its exponential effect on rates of energy flux and thus, potentially, on rates of biological interaction and diversification. However, limited support for this hypothesis has been found to date. We tested the fit of this model on the variation of tree species richness across the Americas. We found that the kinetic hypothesis accurately predicts the upper bound of the relationship between the inverse of temperature (1,000/kK) and the natural logarithm of species richness. In addition, we found that the number of frost days organizes a substantial portion of the residual variation. Historically, attempts to explain large-scale variation of species richness has focused on gradients of independent variables, but explanatory power has been limited. More than a gradient, the fit of the upper bound of the exponential Boltzmann temperature model of variation of observed species richness can be seen as an upper limit on the species richness per unit of MAT. Likewise, the distribution of the residuals of the upper bound model in function of the number of days with freezing temperatures, shows the importance of environmental thresholds, rather than gradients driving species richness variation.

scholarly journals Testing Seven Hypotheses to Determine What Explains the Current Planthopper (Fulgoridae) Geographical and Species Richness Patterns in China

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 892
Author(s):  
Zheng-Xue Zhao ◽  
Lin Yang ◽  
Jian-Kun Long ◽  
Zhi-Min Chang ◽  
Zheng-Xiang Zhou ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Model Averaging ◽  
Ordinary Least Squares ◽  
Environmental Variable ◽  
Vital Role ◽  
Mean Annual Temperature ◽  
Spatial Error ◽  
Richness Patterns

Although many hypotheses have been proposed to understand the mechanisms underlying large-scale richness patterns, the environmental determinants are still poorly understood, particularly in insects. Here, we tested the relative contributions of seven hypotheses previously proposed to explain planthopper richness patterns in China. The richness patterns were visualized at a 1° × 1° grid size, using 14,722 distribution records for 1335 planthoppers. We used ordinary least squares and spatial error simultaneous autoregressive models to examine the relationships between richness and single environmental variables and employed model averaging to assess the environmental variable relative roles. Species richness was unevenly distributed, with high species numbers occurring in the central and southern mountainous areas. The mean annual temperature change since the Last Glacial Maximum was the most important factor for richness patterns, followed by mean annual temperature and net primary productivity. Therefore, historical climate stability, ambient energy, and productivity hypotheses were supported strongly, but orogenic processes and geological isolation may also play a vital role.

scholarly journals Patterns, determinants and models of woody plant diversity in China

2010 ◽  
Vol 278 (1715) ◽  
pp. 2122-2132 ◽  
Author(s):  
Zhiheng Wang ◽  
Jingyun Fang ◽  
Zhiyao Tang ◽  
Xin Lin
Keyword(s):  
Species Richness ◽  
Woody Plants ◽  
Large Scale ◽  
Explanatory Power ◽  
Woody Species ◽  
Tropical Species ◽  
Controversial Issues ◽  
Strongly Correlated ◽  
Distribution Maps ◽  
The Mean

What determines large-scale patterns of species richness remains one of the most controversial issues in ecology. Using the distribution maps of 11 405 woody species in China, we compared the effects of habitat heterogeneity, human activities and different aspects of climate, particularly environmental energy, water–energy dynamics and winter frost, and explored how biogeographic affinities (tropical versus temperate) influence richness–climate relationships. We found that the species richness of trees, shrubs, lianas and all woody plants strongly correlated with each other, and more strongly correlated with the species richness of tropical affinity than with that of temperate affinity. The mean temperature of the coldest quarter was the strongest predictor of species richness, and its explanatory power for species richness was significantly higher for tropical affinity than for temperate affinity. These results suggest that the patterns of woody species richness mainly result from the increasing intensity of frost filtering for tropical species from the equator/lowlands towards the poles/highlands, and hence support the freezing-tolerance hypothesis. A model based on these results was developed, which explained 76–85% of species richness variation in China, and reasonably predicted the species richness of woody plants in North America and the Northern Hemisphere.

scholarly journals Spatial scale changes the relationship between beta diversity, species richness and latitude

2018 ◽  
Vol 5 (9) ◽  
pp. 181168 ◽  
Author(s):  
Rachakonda Sreekar ◽  
Masatoshi Katabuchi ◽  
Akihiro Nakamura ◽  
Richard T. Corlett ◽  
J. W. Ferry Slik ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Scale ◽  
Large Scale ◽  
Spatial Scales ◽  
Asia Pacific ◽  
Β Diversity ◽  
Sample Representativeness ◽  
Tree Communities ◽  
Tree Data ◽  
The Relationship

The relationship between β-diversity and latitude still remains to be a core question in ecology because of the lack of consensus between studies. One hypothesis for the lack of consensus between studies is that spatial scale changes the relationship between latitude and β-diversity. Here, we test this hypothesis using tree data from 15 large-scale forest plots (greater than or equal to 15 ha, diameter at breast height ≥ 1 cm) across a latitudinal gradient (3–30 o ) in the Asia-Pacific region. We found that the observed β-diversity decreased with increasing latitude when sampling local tree communities at small spatial scale (grain size ≤0.1 ha), but the observed β-diversity did not change with latitude when sampling at large spatial scales (greater than or equal to 0.25 ha). Differences in latitudinal β-diversity gradients across spatial scales were caused by pooled species richness (γ-diversity), which influenced observed β-diversity values at small spatial scales, but not at large spatial scales. Therefore, spatial scale changes the relationship between β-diversity, γ-diversity and latitude, and improving sample representativeness avoids the γ-dependence of β-diversity.

scholarly journals Modeling Spatial Innovation Diffusion from Radiocarbon Dates and Regression Residuals: The Case of Early Old World Pottery

Radiocarbon ◽  
2014 ◽  
Vol 56 (02) ◽  
pp. 723-732 ◽  
Author(s):  
Fabio Silva ◽  
James Steele ◽  
Kevin Gibbs ◽  
Peter Jordan
Keyword(s):  
Innovation Diffusion ◽  
Large Scale ◽  
Explanatory Power ◽  
Lower Latitude ◽  
Mean Annual Temperature ◽  
Radiocarbon Dates ◽  
Old World ◽  
Spatiotemporal Trends ◽  
Regression Residuals ◽  
Early Pottery

This article introduces a method of exploratory analysis of the geographical factors influencing large-scale innovation diffusion, and illustrates its application to the case of early pottery dispersal in the Old World. Regression techniques are used to identify broad-scale spatiotemporal trends in the innovation's first occurrence, and regression residuals are then analyzed to identify geographical variation (climate, biomes) that may have influenced local rates of diffusion. The boundaries between the modeled diffusion zones segregate the western half of the map into a Eurasian hunter-gatherer pottery-using zone affiliated by cultural descent to the Siberian center of innovation, and a lower-latitude farming and pastoralist zone affiliated by cultural descent to the north African center of innovation. However, the correlation coefficients suggest that this baseline model has limited explanatory power, with geographical patterning in the residuals indicating that habitat also greatly affected rates of spread of the new technology. Earlier-than-predicted ages for early pottery tend to occur in locations with mean annual temperature in the range approximately 0–15°. This favorable temperature range typically includes Mediterranean, grassland, and temperate forest biome types, but of these, the Mediterranean and the temperate deciduous forest biomes are the only ones on which regression residuals indicate earlier-than-predicted first observed pottery dates.

scholarly journals Modeling Spatial Innovation Diffusion from Radiocarbon Dates and Regression Residuals: The Case of Early Old World Pottery

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 723-732 ◽  
Author(s):  
Fabio Silva ◽  
James Steele ◽  
Kevin Gibbs ◽  
Peter Jordan
Keyword(s):  
Innovation Diffusion ◽  
Large Scale ◽  
Explanatory Power ◽  
Lower Latitude ◽  
Mean Annual Temperature ◽  
Radiocarbon Dates ◽  
Old World ◽  
Spatiotemporal Trends ◽  
Regression Residuals ◽  
Early Pottery

This article introduces a method of exploratory analysis of the geographical factors influencing large-scale innovation diffusion, and illustrates its application to the case of early pottery dispersal in the Old World. Regression techniques are used to identify broad-scale spatiotemporal trends in the innovation's first occurrence, and regression residuals are then analyzed to identify geographical variation (climate, biomes) that may have influenced local rates of diffusion. The boundaries between the modeled diffusion zones segregate the western half of the map into a Eurasian hunter-gatherer pottery-using zone affiliated by cultural descent to the Siberian center of innovation, and a lower-latitude farming and pastoralist zone affiliated by cultural descent to the north African center of innovation. However, the correlation coefficients suggest that this baseline model has limited explanatory power, with geographical patterning in the residuals indicating that habitat also greatly affected rates of spread of the new technology. Earlier-than-predicted ages for early pottery tend to occur in locations with mean annual temperature in the range approximately 0–15°. This favorable temperature range typically includes Mediterranean, grassland, and temperate forest biome types, but of these, the Mediterranean and the temperate deciduous forest biomes are the only ones on which regression residuals indicate earlier-than-predicted first observed pottery dates.

Geographic variation in the relationship between large-scale environmental determinants and bat species richness

2018 ◽  
Vol 27 ◽  
pp. 1-8 ◽  
Author(s):  
Davi Mello Cunha Crescente Alves ◽  
José Alexandre Felizola Diniz-Filho ◽  
Kelly da Silva e Souza ◽  
Sidney Feitosa Gouveia ◽  
Fabricio Villalobos
Keyword(s):  
Species Richness ◽  
Geographic Variation ◽  
Large Scale ◽  
Environmental Determinants ◽  
The Relationship

scholarly journals Land cover drives large scale productivity-diversity relationships in Irish vascular plants

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7035 ◽  
Author(s):  
Hannah J. White ◽  
Willson Gaul ◽  
Dinara Sadykova ◽  
Lupe León-Sánchez ◽  
Paul Caplat ◽  
...  
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Large Scale ◽  
Vegetation Index ◽  
Scale Effects ◽  
Spatial Scales ◽  
Vascular Plant ◽  
Regional Scale ◽  
The Impact ◽  
The Relationship

The impact of productivity on species diversity is often studied at small spatial scales and without taking additional environmental factors into account. Focusing on small spatial scales removes important regional scale effects, such as the role of land cover heterogeneity. Here, we use a regional spatial scale (10 km square) to establish the relationship between productivity and vascular plant species richness across the island of Ireland that takes into account variation in land cover. We used generalized additive mixed effects models to relate species richness, estimated from biological records, to plant productivity. Productivity was quantified by the satellite-derived enhanced vegetation index. The productivity-diversity relationship was fitted for three land cover types: pasture-dominated, heterogeneous, and non-pasture-dominated landscapes. We find that species richness decreases with increasing productivity, especially at higher productivity levels. This decreasing relationship appears to be driven by pasture-dominated areas. The relationship between species richness and heterogeneity in productivity (both spatial and temporal) varies with land cover. Our results suggest that the impact of pasture on species richness extends beyond field level. The effect of human modified landscapes, therefore, is important to consider when investigating classical ecological relationships, particularly at the wider landscape scale.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

New ''Cold War''

2020 ◽  
pp. 27-34
Author(s):  
Vladimir Batiuk
Keyword(s):  
Cold War ◽  
Nuclear Weapons ◽  
Armed Conflict ◽  
Large Scale ◽  
Arms Race ◽  
Ideological Struggle ◽  
Nuclear Arms Race ◽  
The Cold War ◽  
The Relationship ◽  
Nuclear Arms

In this article, the ''Cold War'' is understood as a situation where the relationship between the leading States is determined by ideological confrontation and, at the same time, the presence of nuclear weapons precludes the development of this confrontation into a large-scale armed conflict. Such a situation has developed in the years 1945–1989, during the first Cold War. We see that something similar is repeated in our time-with all the new nuances in the ideological struggle and in the nuclear arms race.

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