Assessing Clark's nutcracker seed-caching flights using maternally inherited mitochondrial DNA of whitebark pine

Maternally inherited mitochondrial DNA haplotypes in whitebark pine (Pinus albicaulis Engelm.) were used to examine the maternal genetic structure at three hierarchical spatial scales: fine scale, coarse scale, and inter population. These data were used to draw inferences into Clark's nutcracker (Nucifraga columbiana Wilson) seed-caching flight distances. Statistical analyses of fine-scale and coarse-scale distribution of haplotypes showed no apparent signs of deviation from a random pattern. This suggests nutcrackers are effective in dispersal of seed within populations, which is consistent with data gathered on nutcracker seed-caching behavior. However, the lack of homogeneity in haplotype frequencies among populations indicates nutcrackers rarely disperse seeds across large gaps (>20 km) in subalpine habitat.

Download Full-text

Hybrid motion illusions as examples of perceptual conflict

Journal of Illusion ◽

10.47691/joi.v2.7084 ◽

2021 ◽

Vol 2 ◽

Author(s):

Arthur Shapiro

Keyword(s):

Spatial Frequency ◽

Spatial Scales ◽

High Spatial Frequency ◽

Natural World ◽

Fine Scale ◽

Frequency Content ◽

Coarse Scale ◽

Trade Offs ◽

Spatial Frequencies ◽

Contrast Information

Shapiro and Hedjar (2019) proposed a shift in the definition of illusion, from ‘differences between perception and reality’ to ‘conflicts between possible constructions of reality’. This paper builds on this idea by presenting a series of motion hybrid images that juxtapose fine scale contrast (high spatial frequency content) with coarse scale contrast-generated motion (low spatial frequency content). As is the case for static hybrid images, under normal viewing conditions the fine scale contrast determines the perception of motion hybrid images; however, if the motion hybrid image is blurred or viewed from a distance, the perception is determined by the coarse scale contrast. The fine scale contrast therefore masks the perception of motion (and sometimes depth) produced by the coarser scale contrast. Since the unblurred movies contain both fine and coarse scale contrast information, but the blurred movies contain only coarse scale contrast information, cells in the brain that respond to low spatial frequencies should respond equally to both blurred and unblurred movies. Since people undoubtedly differ in the optics of their eyes and most likely in the neural processes that resolve conflict across scales, the paper suggests that motion hybrid images illustrate trade-offs between spatial scales that are important for understanding individual differences in perceptions of the natural world.

Download Full-text

Extreme environmental variation sharpens selection that drives the evolution of a mutualism

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2007.0449 ◽

2007 ◽

Vol 274 (1620) ◽

pp. 1799-1805 ◽

Cited By ~ 25

Author(s):

Adam M Siepielski ◽

Craig W Benkman

Keyword(s):

Adaptive Evolution ◽

Species Interactions ◽

Evolutionary Dynamics ◽

Phenotypic Selection ◽

Whitebark Pine ◽

Nucifraga Columbiana ◽

Seed Predator ◽

Clark's Nutcracker ◽

Small Seed ◽

Seed Crops

The importance of infrequent events for both adaptive evolution and the evolution of species interactions is largely unknown. We investigated how the infrequent production of large seed crops (masting) of a bird-dispersed tree (whitebark pine, Pinus albicaulis ) influenced phenotypic selection exerted by its primary avian seed predator–disperser, the Clark's nutcracker ( Nucifraga columbiana ). Selection was not evident during common years of low seed abundance, whereas it was replicated among areas and favoured traits facilitating seed dispersal during infrequent years of high seed abundance. Since nutcrackers act mostly as seed predators during small seed crops but as seed dispersers during the largest seed crops, trees experienced strong selection from nutcrackers only during infrequent years when the interaction was most strongly mutualistic. Infrequent events can thus be essential to both adaptive evolution and the evolutionary dynamics of species interactions.

Download Full-text

Variability in forest floor at different spatial scales in a natural forest in the Carpathians: effect of windthrows and mesorelief

Canadian Journal of Forest Research ◽

10.1139/x08-100 ◽

2008 ◽

Vol 38 (10) ◽

pp. 2596-2606 ◽

Cited By ~ 27

Author(s):

P. Šamonil ◽

K. Král ◽

J. Douda ◽

B. Šebková

Keyword(s):

Spatial Variability ◽

Spatial Dependence ◽

Forest Floor ◽

Spatial Scales ◽

Beech Forest ◽

High Variability ◽

Organic Horizon ◽

Fine Scale ◽

Coarse Scale ◽

Organic Horizons

Spatial variability of humus properties in a natural fir–beech forest was studied along with the influence of windthrows and mesorelief on this variability. In 1720 windthrows the thickness and form of the organic horizons were studied in three positions — mound, pit, and undisturbed control. On undisturbed sites, substantial variability of thickness and forms of the organic horizons was found on a fine scale (0–10 m). Close spatial dependence of some humus characteristics was found on a coarser scale (20–120 m). The mesorelief was found to be one of the key autocorrelation factors. The level of spatial dependence was not uniform; it differed between the fermented and humification horizons and among their forms. The presence of windthrows increased the variability of humus thickness on both fine (0–10 m) and coarse (level of entire locality, i.e., 11 ha) scales. However, windthrows did not increase the variability of organic horizon forms (OHFs) on a fine scale. High variability of OHFs is probably a property of fully developed mature humus in a natural fir–beech forest. On a coarse scale, the presence of pits increased the frequency of fermented zoogenous and humification residual horizons on the study area.

Download Full-text

Water availability drives signatures of local adaptation in whitebark pine (Pinus albicaulis Englm.) across fine spatial scales of the Lake Tahoe Basin, USA

10.1101/056317 ◽

2016 ◽

Author(s):

Brandon M. Lind ◽

Christopher J Friedline ◽

Jill L. Wegrzyn ◽

Patricia E. Maloney ◽

Detlev R. Vogler ◽

...

Keyword(s):

Genetic Variation ◽

Local Adaptation ◽

Water Availability ◽

Spatial Scales ◽

Lake Tahoe ◽

Allele Frequencies ◽

Fine Scale ◽

Whitebark Pine ◽

Lake Tahoe Basin ◽

Tahoe Basin

ABSTRACTPatterns of local adaptation at fine spatial scales are central to understanding how evolution proceeds, and are essential to the effective management of economically and ecologically important forest tree species. Here, we employ single and multilocus analyses of genetic data (n = 116,231 SNPs) to describe signatures of fine-scale adaptation within eight whitebark pine (Pinus albicaulis Engelm.) populations across the local extent of the environmentally heterogeneous Lake Tahoe Basin, USA. We show that despite highly shared genetic variation (FST = 0.0069) there is strong evidence for adaptation to the rain shadow experienced across the eastern Sierra Nevada. Specifically, we build upon evidence from a common garden study and find that allele frequencies of loci associated with four phenotypes (mean = 236 SNPs), 18 environmental variables (mean = 99 SNPs), and those detected through genetic differentiation (n = 110 SNPs) exhibit significantly higher signals of selection (covariance of allele frequencies) than could be expected to arise, given the data. We also provide evidence that this covariance tracks environmental measures related to soil water availability through subtle allele frequency shifts across populations. Our results replicate empirical support for theoretical expectations of local adaptation for populations exhibiting strong gene flow and high selective pressures, and suggest that ongoing adaptation of many P. albicaulis populations within the Lake Tahoe Basin will not be constrained by the lack of genetic variation. Even so, some populations exhibit low levels of heritability for the traits presumed to be related to fitness. These instances could be used to prioritize management to maintain adaptive potential. Overall, we suggest that established practices regarding whitebark pine conservation be maintained, with the additional context of fine-scale adaptation.

Download Full-text

Assessing trends and vulnerabilities in the mutualism between whitebark pine (Pinus albicaulis) and Clark’s nutcracker (Nucifraga columbiana) in national parks of the Sierra-Cascade region

PLoS ONE ◽

10.1371/journal.pone.0227161 ◽

2020 ◽

Vol 15 (10) ◽

pp. e0227161

Author(s):

Chris Ray ◽

Regina M. Rochefort ◽

Jason I. Ransom ◽

Jonathan C. B. Nesmith ◽

Sylvia A. Haultain ◽

...

Keyword(s):

National Parks ◽

Pinus Albicaulis ◽

Whitebark Pine ◽

Nucifraga Columbiana ◽

Clark's Nutcracker

Download Full-text

Clark's Nutcracker (Nucifraga columbiana)

10.2173/bna.331 ◽

1998 ◽

Cited By ~ 14

Author(s):

Diana F. Tomback

Keyword(s):

Nucifraga Columbiana ◽

Clark's Nutcracker

Download Full-text

Clark's Nutcracker (Nucifraga columbiana)

10.2173/bow.clanut.01 ◽

2020 ◽

Author(s):

Diana F. Tomback

Keyword(s):

Nucifraga Columbiana ◽

Clark's Nutcracker

Download Full-text

Repeated surveying over 6 years reveals that fine-scale habitat variables are key to tropical mountain ant assemblage composition and functional diversity

Scientific Reports ◽

10.1038/s41598-020-80077-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mulalo M. Muluvhahothe ◽

Grant S. Joseph ◽

Colleen L. Seymour ◽

Thinandavha C. Munyai ◽

Stefan H. Foord

Keyword(s):

Climate Change ◽

Species Composition ◽

High Altitude ◽

Functional Diversity ◽

Large Scale ◽

Climate Models ◽

Spatial Scales ◽

Abiotic Factors ◽

Composition Analysis ◽

Fine Scale

AbstractHigh-altitude-adapted ectotherms can escape competition from dominant species by tolerating low temperatures at cooler elevations, but climate change is eroding such advantages. Studies evaluating broad-scale impacts of global change for high-altitude organisms often overlook the mitigating role of biotic factors. Yet, at fine spatial-scales, vegetation-associated microclimates provide refuges from climatic extremes. Using one of the largest standardised data sets collected to date, we tested how ant species composition and functional diversity (i.e., the range and value of species traits found within assemblages) respond to large-scale abiotic factors (altitude, aspect), and fine-scale factors (vegetation, soil structure) along an elevational gradient in tropical Africa. Altitude emerged as the principal factor explaining species composition. Analysis of nestedness and turnover components of beta diversity indicated that ant assemblages are specific to each elevation, so species are not filtered out but replaced with new species as elevation increases. Similarity of assemblages over time (assessed using beta decay) did not change significantly at low and mid elevations but declined at the highest elevations. Assemblages also differed between northern and southern mountain aspects, although at highest elevations, composition was restricted to a set of species found on both aspects. Functional diversity was not explained by large scale variables like elevation, but by factors associated with elevation that operate at fine scales (i.e., temperature and habitat structure). Our findings highlight the significance of fine-scale variables in predicting organisms’ responses to changing temperature, offering management possibilities that might dilute climate change impacts, and caution when predicting assemblage responses using climate models, alone.

Download Full-text

Spatial Downscaling of TRMM Precipitation Using Geostatistics and Fine Scale Environmental Variables

Advances in Meteorology ◽

10.1155/2013/237126 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 33

Author(s):

No-Wook Park

Keyword(s):

Environmental Variables ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Tropical Rainfall Measuring Mission ◽

Predictive Performance ◽

Environmental Modeling ◽

Fine Scale ◽

Coarse Scale ◽

Uncertainty Measures ◽

Trmm Precipitation

A geostatistical downscaling scheme is presented and can generate fine scale precipitation information from coarse scale Tropical Rainfall Measuring Mission (TRMM) data by incorporating auxiliary fine scale environmental variables. Within the geostatistical framework, the TRMM precipitation data are first decomposed into trend and residual components. Quantitative relationships between coarse scale TRMM data and environmental variables are then estimated via regression analysis and used to derive trend components at a fine scale. Next, the residual components, which are the differences between the trend components and the original TRMM data, are then downscaled at a target fine scale via area-to-point kriging. The trend and residual components are finally added to generate fine scale precipitation estimates. Stochastic simulation is also applied to the residual components in order to generate multiple alternative realizations and to compute uncertainty measures. From an experiment using a digital elevation model (DEM) and normalized difference vegetation index (NDVI), the geostatistical downscaling scheme generated the downscaling results that reflected detailed characteristics with better predictive performance, when compared with downscaling without the environmental variables. Multiple realizations and uncertainty measures from simulation also provided useful information for interpretations and further environmental modeling.

Download Full-text