scholarly journals Local adaptation primes cold-edge populations for range expansion but not warming-induced range shifts

2018 ◽  
Author(s):  
Anna L. Hargreaves ◽  
Christopher G. Eckert
Keyword(s):  
Range Expansion ◽  
Seed Quality ◽  
Regional Scale ◽  
High Elevation ◽  
Range Shifts ◽  
Relative Fitness ◽  
Transplant Experiment ◽  
Experimental Warming ◽  
Heat Accumulation ◽  
Edge Populations

AbstractAccording to theory, edge populations may be the best suited to initiate range expansions and climate-driven range shifts if they are locally adapted to extreme edge conditions, or the worst suited to colonize beyond-range habitat if their offspring are genetically and competitively inferior. We tested these contrasting predictions by comparing fitness of low, mid, and high-elevation (edge) populations of the annual Rhinanthus minor, transplanted throughout and above its elevational distribution under natural and experimentally-warmed conditions. Seed from low-quality edge habitat had inferior emergence across sites, but high-elevation seeds were also locally adapted. High-elevation plants initiated flowering earlier than plants from lower populations, required less heat accumulation to mature seed, and so achieved higher lifetime fitness at high elevations. Fitness was strongly reduced above the range, but adaptive phenology enhanced the relative fitness of high-elevation seeds. Experimental warming improved fitness above the range, confirming climate’s importance in limiting R. minor’s distribution, but eliminated the advantage of local cold-edge populations. These results provide experimental support for recent models in which cold-adapted edge populations do not always facilitate warming-induced range shifts. The highest fitness above the range was achieved by a ‘super edge phenotype’ from a neighboring mountain, suggesting key adaptations exist at the regional scale even if absent from local edge populations. Our results demonstrate that assessing the value of edge populations will not be straightforward, but suggest that a regional approach to their conservation, potentially enhancing gene flow among them, might maximize species’ ability to respond to global change.SignificanceIndividuals from range-edge populations are the most likely to disperse to habitat beyond the species current range, but are they best suited to colonize it? Our multi-year transplant experiment throughout and above the elevational range of an annual herb in the Canadian Rocky Mountains found that adaptive flowering phenology enhanced the fitness of high-edge seeds above the range, outweighing detrimental effects of poor seed quality. However, only one edge population maintained its advantage over central populations under experimental warming. While edge populations were most likely to drive range expansion, adaptation to cold climates may not help them initiate range shifts in response to climate warming, unless superior genotypes spread among isolated edge populations.

scholarly journals Effect of Different Packaging Materials and Storage Environments on Seed Quality of Sesame (Sesamum Indicum L.)

2019 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Hnin Thida Nyo ◽  
Nyein Nyein Htwe ◽  
Kyaw Kyaw Win
Keyword(s):  
Moisture Content ◽  
Seed Quality ◽  
Carbon Dioxide Concentration ◽  
Sesame Seed ◽  
Germination Percentage ◽  
Release Time ◽  
Packaging Materials ◽  
Dormancy Release ◽  
Heat Accumulation ◽  
And Storage

The speed of the deterioration of oil-seeds depends on conditions of the storage environment and understanding dormancy release time is important to increase the amount and uniformity in germination. Therefore, the present study was conducted to evaluate the effect of different packaging materials and storage environments on viability and dormancy of sesame. The black sesame seed was stored in three packaging materials (woven polypropylene bag, IRRI super bag, metal bin) under two environment conditions (ambient and cold storage) for eight-month (initial storage, 2-month, 4-month, 6-month and 8-month). The effect of storage environments, packaging materials and storage durations on germination percentage, germination index, seedling vigor index I and II were significant. The moisture content decreased in the early parts of storage periods and then increased in later. The moisture content of seeds in the packaging materials increased in long storage due to the effect of seed respiration and heat accumulation in a package. Higher viability was observed in ambient storage, and in a woven polypropylene bag. Because the dormancy release was slow in low- temperature condition and the carbon dioxide concentration in the airtight package inhibited the dormancy break. It also increased during storage and the earliest fully dormancy break has occurred in six-month of woven polypropylene bag storage under ambient condition. Therefore, the germination and dormancy release of sesame were influenced by storage environments packaging materials and storage durations.

scholarly journals Scale-dependent portfolio effects explain growth inflation and volatility reduction in landscape demography

2017 ◽  
Vol 114 (47) ◽  
pp. 12507-12511 ◽  
Author(s):  
Cang Hui ◽  
Gordon A. Fox ◽  
Jessica Gurevitch
Keyword(s):  
Invasive Species ◽  
Time Series ◽  
Regional Scale ◽  
Scaling Up ◽  
Range Shifts ◽  
Attainable Set ◽  
Local Populations ◽  
Accumulation Curve ◽  
Invasive Organisms ◽  
Regional Population

Population demography is central to fundamental ecology and for predicting range shifts, decline of threatened species, and spread of invasive organisms. There is a mismatch between most demographic work, carried out on few populations and at local scales, and the need to predict dynamics at landscape and regional scales. Inspired by concepts from landscape ecology and Markowitz’s portfolio theory, we develop a landscape portfolio platform to quantify and predict the behavior of multiple populations, scaling up the expectation and variance of the dynamics of an ensemble of populations. We illustrate this framework using a 35-y time series on gypsy moth populations. We demonstrate the demography accumulation curve in which the collective growth of the ensemble depends on the number of local populations included, highlighting a minimum but adequate number of populations for both regional-scale persistence and cross-scale inference. The attainable set of landscape portfolios further suggests tools for regional population management for both threatened and invasive species.

scholarly journals Rapid changes in phenotype distribution during range expansion in a migratory bird

2011 ◽  
Vol 279 (1727) ◽  
pp. 411-416 ◽  
Author(s):  
Tómas Grétar Gunnarsson ◽  
William J. Sutherland ◽  
José A. Alves ◽  
Peter M. Potts ◽  
Jennifer A. Gill
Keyword(s):  
Population Growth ◽  
Range Expansion ◽  
Migratory Bird ◽  
Relative Fitness ◽  
Conservation Strategies ◽  
Small Male ◽  
New Locations ◽  
Phenotype Distribution ◽  
Dispersal Probability ◽  
Male Morphology

The capacity of species to track changing environmental conditions is a key component of population and range changes in response to environmental change. High levels of local adaptation may constrain expansion into new locations, while the relative fitness of dispersing individuals will influence subsequent population growth. However, opportunities to explore such processes are rare, particularly at scales relevant to species-based conservation strategies. Icelandic black-tailed godwits, Limosa limosa islandica , have expanded their range throughout Iceland over the last century. We show that current male morphology varies strongly in relation to the timing of colonization across Iceland, with small males being absent from recently occupied areas. Smaller males are also proportionately more abundant on habitats and sites with higher breeding success and relative abundance of females. This population-wide spatial structuring of male morphology is most likely to result from female preferences for small males and better-quality habitats increasing both small-male fitness and the dispersal probability of larger males into poorer-quality habitats. Such eco-evolutionary feedbacks may be a key driver of rates of population growth and range expansion and contraction.

scholarly journals Thermal-metabolic phenotypes of the lizard Podarcis muralis differ across elevation, but converge in high elevation hypoxia

2021 ◽  
Author(s):  
Brooke L. Bodensteiner ◽  
Eric J. Gangloff ◽  
Laura Kouyoumdjian ◽  
Martha M. Muñoz ◽  
Fabien Aubret
Keyword(s):  
Sea Level ◽  
Elevational Gradient ◽  
High Elevation ◽  
Oxygen Availability ◽  
Metabolic Phenotype ◽  
Transplant Experiment ◽  
Range Limit ◽  
Podarcis Muralis ◽  
Metabolic Phenotypes ◽  
Preferred Temperatures

In response to a warming climate, many montane species are shifting upslope to track the emergence of preferred temperatures. Characterizing patterns of variation in metabolic, physiological, and thermal traits along an elevational gradient, and the plastic potential of these traits, is necessary to understand current and future responses to abiotic constraints at high elevations, including limited oxygen availability. We performed a transplant experiment with the upslope-colonizing common wall lizard (Podarcis muralis) in which we measured nine aspects of thermal physiology and aerobic capacity in lizards from replicate low- (400 m above sea level [ASL]) and high-elevation (1700 m ASL) populations. We first measured traits at their elevation of origin and then transplanted half of each group to extreme high elevation (2900 m ASL; above the current elevational range limit of this species), where oxygen availability is reduced by ∼25% relative to sea level. After three weeks of acclimation, we again measured these traits in both the transplanted and control groups. The multivariate thermal-metabolic phenotypes of lizards originating from different elevations differed clearly when measured at the elevation of origin. For example, high-elevation lizards are more heat tolerant than low-elevation counterparts (countergradient variation). Yet, these phenotypes converged after exposure to reduced oxygen availability at extreme high elevation, suggesting limited plastic responses under this novel constraint. Our results suggest that high-elevation populations are well-suited to their oxygen environments, but that plasticity in the thermal-metabolic phenotype does not pre-adapt these populations to colonize more hypoxic environments at higher elevations.

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 Carbon Limitation and Drought Sensitivity at Contrasting Elevation and Competition of Abies pinsapo Forests. Does Experimental Thinning Enhance Water Supply and Carbohydrates?

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1132 ◽  
Author(s):  
Victor Lechuga ◽  
Vinicio Carraro ◽  
Benjamín Viñegla ◽  
José Antonio Carreira ◽  
Juan Carlos Linares
Keyword(s):  
Regional Scale ◽  
Secondary Growth ◽  
Stand Density ◽  
High Elevation ◽  
Carbon Limitation ◽  
Flow Density ◽  
Xylem Water Potential ◽  
Local Climate ◽  
Water Balances ◽  
Abies Pinsapo

Stand-level competition and local climate influence tree responses to increased drought at the regional scale. To evaluate stand density and elevation effects on tree carbon and water balances, we monitored seasonal changes in sap-flow density (SFD), gas exchange, xylem water potential, secondary growth, and non-structural carbohydrates (NSCs) in Abies pinsapo. Trees were subjected to experimental thinning within a low-elevation stand (1200 m), and carbon and water balances were compared to control plots at low and high elevation (1700 m). The hydraulic conductivity and the resistance to cavitation were also characterized, showing relatively high values and no significant differences among treatments. Trees growing at higher elevations presented the highest SFD, photosynthetic rates, and secondary growth, mainly because their growing season was extended until summer. Trees growing at low elevation reduced SFD during late spring and summer while SFD and secondary growth were significantly higher in the thinned stands. Declining NSC concentrations in needles, branches, and sapwood suggest drought-induced control of the carbon supply status. Our results might indicate potential altitudinal shifts, as better performance occurs at higher elevations, while thinning may be suitable as adaptive management to mitigate drought effects in endangered Mediterranean trees.

Causes and consequences of deer browsing on red trillium (Trillium erectum) along an elevational gradient

Botany ◽  
2020 ◽  
Vol 98 (8) ◽  
pp. 469-478
Author(s):  
Diane Auberson-Lavoie ◽  
Mark Vellend
Keyword(s):  
Growth Rates ◽  
Range Expansion ◽  
Negative Impact ◽  
Elevational Gradient ◽  
High Elevation ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Deer Herbivory ◽  
One Year ◽  
Elevational Range

Models of ecological responses to climate warming predict species’ migration towards higher latitudes or elevations. However, models often neglect nonclimatic factors, such as herbivory, which could slow down or prevent geographic range expansion. A previous study in Mont Mégantic National Park (Quebec) found that in one year (2016), browsing by white-tailed deer on Trillium erectum L. was substantially higher at high elevations than low elevations. Under the hypothesis that deer herbivory could limit the upper elevational range expansion of T. erectum, here we ask (i) whether herbivory increased with elevation during two additional years (2017 and 2018), (ii) whether the rate of deer visitation increases with elevation, and (iii) whether the effect of herbivory on relative growth rates increases with elevation. Contrary to the earlier study, we did not find a significant trend of herbivory with elevation, although there was a weak positive relationship between deer visitation and elevation. We found a strong negative impact of browsing on relative growth rates, but the magnitude of this effect did not vary with elevation. Our results thus do not support the hypothesis that herbivory limits the range of T. erectum at high elevation, but herbivory could have a negative impact on populations in general if the browsing rate remains high.

Coupling the delta-h parametrization with melt beneath a supraglacial debris cover: an evaluation across 54 glaciers in the southern European Alps

2021 ◽  
Author(s):  
Francesco Avanzi ◽  
Simone Gabellani ◽  
Edoardo Cremonese ◽  
Umberto Morra di Cella ◽  
Matthias Huss
Keyword(s):  
Mass Balance ◽  
Regional Scale ◽  
High Elevation ◽  
Glacier Mass Balance ◽  
European Alps ◽  
Hydrological Models ◽  
Elevation Gradients ◽  
Ice Flow ◽  
Thickness Change ◽  
Debris Cover

<p>Glacier mass balance is an essential component of the water budget of high-elevation and high-latitude regions, and yet this process is rather oversimplified in most hydrological models. This oversimplification is particularly relevant when it comes to representing two mechanisms: ice flow dynamics and melt beneath a supraglacial debris cover. In 2010, Huss et al. proposed a parsimonious approach to account for  glacier dynamics in hydrological models without solving complex equations of three-dimensional ice flow, the so-called delta-h parametrization. On the other hand, accounting for melt of debris-covered ice is still challenging as  estimates of debris thickness are rare. </p><p>Here, we leveraged a distributed dataset of glacier-thickness change to derive a glacier-specific delta-h parametrization for 54 glaciers across the Aosta Valley (Italy), as well as  develop a novel approach for modeling melt beneath supraglacial debris based on residuals between locally observed change in thickness and that expected by regional elevation gradients. This approach does not require any on-the-ground data on debris cover, and as such it is particularly suited for ungauged regions where remote sensing is the only, feasible source of information for modeling. </p><p>We found an expected, significant variability in both the delta-h parametrization and residuals over debris-covered ice across glaciers, with somewhat steeper orographic gradients in the former compared to the curves originally proposed by Huss et al. for Swiss glaciers. At a regional scale, the glacier mass balance showed a clear transition between a regime dominated by active glacier flow above 2,300 m ASL and a debris-dominated regime below this elevation threshold, which makes accounting for melt in the debris-covered area essential to correctly capture the future fate of low-elevation glaciers. Implementing the delta-h parametrization and our proposed approach to melt beneath supraglacial debris into S3M, a distributed cryospheric model, yielded an improved realism in estimates of future changes in glacier geometry  compared to assuming non-dynamic downwasting.</p>

Postglacial vegetation, fire, and climate history of the Siskiyou Mountains, Oregon, USA

2005 ◽  
Vol 64 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Christy E. Briles ◽  
Cathy Whitlock ◽  
Patrick J. Bartlein
Keyword(s):  
Environmental History ◽  
Fire Regime ◽  
Regional Scale ◽  
Natural Disturbance ◽  
High Elevation ◽  
Early Holocene ◽  
Climate History ◽  
Fire Activity ◽  
History Of ◽  
Siskiyou Mountains

AbstractThe forests of the Siskiyou Mountains are among the most diverse in North America, yet the long-term relationship among climate, diversity, and natural disturbance is not well known. Pollen, plant macrofossils, and high-resolution charcoal data from Bolan Lake, Oregon, were analyzed to reconstruct a 17,000-yr-long environmental history of high-elevation forests in the region. In the late-glacial period, the presence of a subalpine parkland of Artemisia, Poaceae, Pinus, and Tsuga with infrequent fires suggests cool dry conditions. After 14,500 cal yr B.P., a closed forest of Abies, Pseudotsuga, Tsuga, and Alnus rubra with more frequent fires developed which indicates more mesic conditions than before. An open woodland of Pinus, Quercus, and Cupressaceae, with higher fire activity than before, characterized the early Holocene and implies warmer and drier conditions than at present. In the late Holocene, Abies and Picea were more prevalent in the forest, suggesting a return to cool wet conditions, although fire-episode frequency remained relatively high. The modern forest of Abies and Pseudotsuga and the present-day fire regime developed ca. 2100 cal yr B.P. and indicates that conditions had become slightly drier than before. Sub-millennial-scale fluctuations in vegetation and fire activity suggest climatic variations during the Younger Dryas interval and within the early Holocene period. The timing of vegetation changes in the Bolan Lake record is similar to that of other sites in the Pacific Northwest and Klamath region, and indicates that local vegetation communities were responding to regional-scale climate changes. The record implies that climate-driven millennial- to centennial-scale vegetation and fire change should be considered when explaining the high floristic diversity observed at present in the Siskiyou Mountains.

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