scholarly journals Decreased Temperature with Increasing Elevation Decreases the End-Season Leaf-to-Wood Reallocation of Resources in Deciduous Betula ermanii Cham. Trees

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 166 ◽  
Author(s):  
Yu Cong ◽  
Mai-He Li ◽  
Kai Liu ◽  
Yong-Cai Dang ◽  
Hu-Dong Han ◽  
...  
Keyword(s):  
Global Warming ◽  
Management Strategies ◽  
Resource Limitation ◽  
Elevational Gradient ◽  
High Elevation ◽  
Tissue Type ◽  
Betula Ermanii ◽  
Plant Resource ◽  
Wood Resource ◽  
Warming World

Global air temperature has increased and continues to increase, especially in high latitude and high altitude areas, which may affect plant resource physiology and thus plant growth and productivity. The resource remobilization efficiency of plants in response to global warming is, however, still poorly understood. We thus assessed end-season resource remobilization from leaves to woody tissues in deciduous Betula ermanii Cham. trees grown along an elevational gradient ranging from 1700 m to 2187 m a.s.l. on Changbai Mountain, northeastern China. We hypothesized that end-season resource remobilization efficiency from leaves to storage tissues increases with increasing elevation or decreasing temperature. To test this hypothesis, concentrations of non-structural carbohydrates (NSCs), nitrogen (N), phosphorus (P), and potassium (K) during peak shoot growth (July) were compared with those at the end of growing season (September on Changbai Mt.) for each tissue type. To avoid leaf phenological effects on parameters, fallen leaves were collected at the end-season. Except for July-shoot NSC and July-leaf K, tissue concentrations of NSC, N, P, and K did not decrease with increasing elevation for both July and September. We found that the end-season leaf-to-wood reallocation efficiency decreased with increasing elevation. This lower reallocation efficiency may result in resource limitation in high-elevation trees. Future warming may promote leaf-to-wood resource reallocation, leading to upward shift of forests to higher elevations. The NSC, N, P, and K accumulated in stems and roots but not in shoots, especially in trees grown close to or at their upper limit, indicating that stems and roots of deciduous trees are the most important storage tissues over winter. Our results contribute to better understand the resource-related ecophysiological mechanisms for treeline formation, and vice versa, to better predict forest dynamics at high elevations in response to global warming. Our study provides resource-related ecophysiological knowledge for developing management strategies for high elevation forests in a rapidly warming world.

scholarly journals Protective Role of Ice Barriers: How Reproductive Organs of Early Flowering and Mountain Plants Escape Frost Injuries

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1031
Author(s):  
Clara Bertel ◽  
Jürgen Hacker ◽  
Gilbert Neuner
Keyword(s):  
Management Strategies ◽  
Woody Species ◽  
Reproductive Organs ◽  
High Elevation ◽  
Protective Role ◽  
Early Spring ◽  
Early Flowering ◽  
Ice Formation ◽  
Species Vulnerability ◽  
Infrared Video

In the temperate zone of Europe, plants flowering in early spring or at high elevation risk that their reproductive organs are harmed by episodic frosts. Focusing on flowers of two mountain and three early-flowering colline to montane distributed species, vulnerability to ice formation and ice management strategies using infrared video thermography were investigated. Three species had ice susceptible flowers and structural ice barriers, between the vegetative and reproductive organs, that prevent ice entrance from the frozen stems. Structural ice barriers as found in Anemona nemorosa and Muscari sp. have not yet been described for herbaceous species that of Jasminum nudiflorum corroborates findings for woody species. Flowers of Galanthus nivalis and Scilla forbesii were ice tolerant. For all herbs, it became clear that the soil acts as a thermal insulator for frost susceptible below ground organs and as a thermal barrier against the spread of ice between individual flowers and leaves. Both ice barrier types presumably promote that the reproductive organs can remain supercooled, and can at least for a certain time-period escape from effects of ice formation. Both effects of ice barriers appear significant in the habitat of the tested species, where episodic freezing events potentially curtail the reproductive success.

Effects of plant availability on population size and dynamics of an insect community: diamondback moth and two of its parasitoids

2014 ◽  
Vol 104 (4) ◽  
pp. 418-431 ◽  
Author(s):  
M. Soufbaf ◽  
Y. Fathipour ◽  
J. Karimzadeh ◽  
M.P. Zalucki
Keyword(s):  
Population Size ◽  
Extinction Risk ◽  
Diamondback Moth ◽  
Resource Limitation ◽  
Insect Community ◽  
Specialist Herbivore ◽  
Plant Availability ◽  
Plant Resource ◽  
Limited Variation ◽  
Density Process

AbstractTo understand the effect of plant availability/structure on the population size and dynamics of insects, a specialist herbivore in the presence of two of its parasitoids was studied in four replicated time-series experiments with high and low plant availabilities; under the latter condition, the herbivore suffered from some periods of resource limitation (starvation) and little plant-related structural refuges. Population dynamics of the parasitoid Cotesia vestalis was governed mainly by the delayed density-dependent process under both plant setups. The parasitoid, Diadegma semiclausum, under different plant availabilities and different coexistence situations (either +competitor or –competitor) showed dynamics patterns that were governed mainly by the delayed density process (significant lags at weeks 2–4). Both the competing parasitoids did not experience beneficial or costly interferences from each other in terms of their own population size when the plant resource was limited. Variation in the Plutella xylostella population under limited plant availability is higher than that under the other plant setup. For both parasitoids, under limited plant setup, the extinction risk was lower when parasitoids were engaged in competition, while under the unlimited plant setup, the mentioned risk was higher when parasitoids competed. In this situation, parasitoids suffered from two forces, competition and higher escaped hosts.

scholarly journals Climate Change and Goat Production: Enteric Methane Emission and Its Mitigation

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 235 ◽  
Author(s):  
Pratap Pragna ◽  
Surinder S. Chauhan ◽  
Veerasamy Sejian ◽  
Brian J. Leury ◽  
Frank R. Dunshea
Keyword(s):  
Global Warming ◽  
Heat Stress ◽  
Management Strategies ◽  
Climate Scenario ◽  
Rumen Fermentation ◽  
Ch4 Emission ◽  
Changing Climate ◽  
Ch4 Production ◽  
Enteric Methane ◽  
The Impact

The ability of an animal to cope and adapt itself to the changing climate virtually depends on the function of rumen and rumen inhabitants such as bacteria, protozoa, fungi, virus and archaea. Elevated ambient temperature during the summer months can have a significant influence on the basic physiology of the rumen, thereby affecting the nutritional status of the animals. Rumen volatile fatty acid (VFA) production decreases under conditions of extreme heat. Growing recent evidence suggests there are genetic variations among breeds of goats in the impact of heat stress on rumen fermentation pattern and VFA production. Most of the effects of heat stress on rumen fermentation and enteric methane (CH4) emission are attributed to differences in the rumen microbial population. Heat stress-induced rumen function impairment is mainly associated with an increase in Streptococcus genus bacteria and with a decrease in the bacteria of Fibrobactor genus. Apart from its major role in global warming and greenhouse effect, enteric CH4 is also considered as a dietary energy loss in goats. These effects warrant mitigating against CH4 production to ensure optimum economic return from goat farming as well as to reduce the impact on global warming as CH4 is one of the more potent greenhouse gases (GHG). The various strategies that can be implemented to mitigate enteric CH4 emission include nutritional interventions, different management strategies and applying advanced biotechnological tools to find solution to reduce CH4 production. Through these advanced technologies, it is possible to identify genetically superior animals with less CH4 production per unit feed intake. These efforts can help the farming community to sustain goat production in the changing climate scenario.

scholarly journals High turn-over rates at the upper range limit and elevational source-sink dynamics in a widespread songbird

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin U. Grüebler ◽  
Johann von Hirschheydt ◽  
Fränzi Korner-Nievergelt
Keyword(s):  
Environmental Gradients ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limit ◽  
Apparent Survival ◽  
Breeding Sites ◽  
Mobile Species ◽  
Source Sink ◽  
Turn Over ◽  
High Elevations

AbstractThe formation of an upper distributional range limit for species breeding along mountain slopes is often based on environmental gradients resulting in changing demographic rates towards high elevations. However, we still lack an empirical understanding of how the interplay of demographic parameters forms the upper range limit in highly mobile species. Here, we study apparent survival and within-study area dispersal over a 700 m elevational gradient in barn swallows (Hirundo rustica) by using 15 years of capture-mark-recapture data. Annual apparent survival of adult breeding birds decreased while breeding dispersal probability of adult females, but not males increased towards the upper range limit. Individuals at high elevations dispersed to farms situated at elevations lower than would be expected by random dispersal. These results suggest higher turn-over rates of breeding individuals at high elevations, an elevational increase in immigration and thus, within-population source-sink dynamics between low and high elevations. The formation of the upper range limit therefore is based on preference for low-elevation breeding sites and immigration to high elevations. Thus, shifts of the upper range limit are not only affected by changes in the quality of high-elevation habitats but also by factors affecting the number of immigrants produced at low elevations.

scholarly journals Provenance Geographical and Climatic Characteristics Influence Budburst Phenology of Southwestern Ponderosa Pine Seedlings

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1067
Author(s):  
Aalap Dixit ◽  
Thomas Kolb ◽  
Owen Burney
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Common Garden ◽  
Elevational Gradient ◽  
High Elevation ◽  
Mean Annual Precipitation ◽  
Positive Trend ◽  
Provenance Variation ◽  
Pine Seedlings ◽  
Budburst Phenology

Ponderosa pine (Pinus ponderosa Lawson & C. Lawson var. scopulorum Engelm.) forests of the southwestern US are threatened by climate change and deforestation. Information about geographic patterns of provenance variation in budburst phenology is needed to make decisions about selecting seed sources for future planting. In this study, provenance variation in the budburst phenology of ponderosa pine seedlings was examined using common garden studies. Seedlings from 21 provenances, representing an elevational gradient in Arizona and New Mexico, were planted in July 2018 at a ponderosa pine-dominated field site in northern Arizona. Field budburst was monitored weekly on all seedlings in the spring of 2019. Field budburst was compared with budburst timing of the same provenances measured under greenhouse conditions. The hypotheses for this study were that (1) budburst varies among provenances, with earlier budburst in low-elevation provenances, and (2) differences in budburst timing among provenances are consistent for seedlings grown in greenhouse and field environments. Field results show that provenances vary in budburst date and that low- and middle-elevation provenances break bud sooner than high-elevation provenances. Field budburst date had a moderate, positive correlation with provenance mean annual precipitation (r = 0.522) and a moderate, negative trend with latitude (r = −0.413). Budburst date of provenances in the greenhouse had a moderate, positive trend with budburst date in the field (r = 0.554), suggesting application of greenhouse results to field plantings. Such information about provenance variation and environmental and geographic trends in budburst timing will be useful for developing species-specific seed transfer guidelines and effective assisted migration strategies in a changing climate.

scholarly journals Range dynamics of mountain plants decrease with elevation

2018 ◽  
Vol 115 (8) ◽  
pp. 1848-1853 ◽  
Author(s):  
Sabine B. Rumpf ◽  
Karl Hülber ◽  
Günther Klonner ◽  
Dietmar Moser ◽  
Martin Schütz ◽  
...  
Keyword(s):  
Plant Species ◽  
Species Abundance ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limits ◽  
European Alps ◽  
Cold Adapted ◽  
Recent Climate ◽  
Range Dynamics ◽  
Mountain Plant

Many studies report that mountain plant species are shifting upward in elevation. However, the majority of these reports focus on shifts of upper limits. Here, we expand the focus and simultaneously analyze changes of both range limits, optima, and abundances of 183 mountain plant species. We therefore resurveyed 1,576 vegetation plots first recorded before 1970 in the European Alps. We found that both range limits and optima shifted upward in elevation, but the most pronounced trend was a mean increase in species abundance. Despite huge species-specific variation, range dynamics showed a consistent trend along the elevational gradient: Both range limits and optima shifted upslope faster the lower they were situated historically, and species’ abundance increased more for species from lower elevations. Traits affecting the species’ dispersal and persistence capacity were not related to their range dynamics. Using indicator values to stratify species by their thermal and nutrient demands revealed that elevational ranges of thermophilic species tended to expand, while those of cold-adapted species tended to contract. Abundance increases were strongest for nutriphilous species. These results suggest that recent climate warming interacted with airborne nitrogen deposition in driving the observed dynamics. So far, the majority of species appear as “winners” of recent changes, yet “losers” are overrepresented among high-elevation, cold-adapted species with low nutrient demands. In the decades to come, high-alpine species may hence face the double pressure of climatic changes and novel, superior competitors that move up faster than they themselves can escape to even higher elevations.

scholarly journals The Coupled Influence of Thermal Physiology and Biotic Interactions on the Distribution and Density of Ant Species along an Elevational Gradient

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 456
Author(s):  
Lacy D. Chick ◽  
Jean-Philippe Lessard ◽  
Robert R. Dunn ◽  
Nathan J. Sanders
Keyword(s):  
Observational Data ◽  
Species Interactions ◽  
Phylogenetic Signal ◽  
Environmental Filtering ◽  
Null Model ◽  
Biotic Interactions ◽  
Elevational Gradient ◽  
High Elevation ◽  
Elevational Range ◽  
Stressful Environments

A fundamental tenet of biogeography is that abiotic and biotic factors interact to shape the distributions of species and the organization of communities, with interactions being more important in benign environments, and environmental filtering more important in stressful environments. This pattern is often inferred using large databases or phylogenetic signal, but physiological mechanisms underlying such patterns are rarely examined. We focused on 18 ant species at 29 sites along an extensive elevational gradient, coupling experimental data on critical thermal limits, null model analyses, and observational data of density and abundance to elucidate factors governing species’ elevational range limits. Thermal tolerance data showed that environmental conditions were likely to be more important in colder, more stressful environments, where physiology was the most important constraint on the distribution and density of ant species. Conversely, the evidence for species interactions was strongest in warmer, more benign conditions, as indicated by our observational data and null model analyses. Our results provide a strong test that biotic interactions drive the distributions and density of species in warm climates, but that environmental filtering predominates at colder, high-elevation sites. Such a pattern suggests that the responses of species to climate change are likely to be context-dependent and more specifically, geographically-dependent.

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