Insect herbivory on snow gum (Eucalyptus pauciflora, Myrtaceae) saplings near the alpine treeline: the influence of local- and landscape-scale processes

2017 ◽  
Vol 65 (7) ◽  
pp. 582 ◽  
Author(s):  
Citra D. Dashiell ◽  
Shannon LeBel ◽  
Peter T. Green ◽  
Susanna E. Venn ◽  
John W. Morgan
Keyword(s):  
Leaf Area ◽  
Insect Herbivory ◽  
High Elevation ◽  
Leaf Thickness ◽  
Canopy Openness ◽  
High Mountain ◽  
Transplant Experiment ◽  
Plant Vigour ◽  
Alpine Treeline ◽  
Australian Alps

The distribution and abundance of plant species in high mountain ecosystems are thought to depend largely on abiotic factors that play out at both landscape scales (e.g. steep environmental gradients affected by increasing elevation) and local scales (e.g. changes in topography, aspect and canopy cover). However, relatively little attention has been paid to biotic interactions, and how these might also change with landscape-wide and local factors. Ecological interactions between plants and insect herbivores are likely to alter species performance and affect local abundance, but their role in the Australian Alps remains largely unexplored. Here, we examine the prediction that the amount of herbivory on saplings of the dominant high elevation tree, snow gum Eucalyptus pauciflora Sieb. ex Spreng. (Myrtaceae), are lower at higher elevation because of increasing environmental stress. Using a reciprocal transplant experiment, we tested the prediction that origin of seed (low, mid, high elevation) has less effect on insect herbivory than environmentally-driven changes in plant morphology (height, leaf thickness, specific leaf area). Across all mountains studied, herbivory was best explained by a combination of plant height, canopy openness, leaf thickness and elevation, but not seed origin. This study highlights the individuality of each mountain environment, at landscape and local scales, as well as the complexity of relationships between environmental change, plants and insects. Given the factors that best explain herbivory across mountains, herbivory may decrease with decreasing productivity associated with increasing elevation, a trend in broad agreement with hypotheses associating leaf area loss to the availability of resources and plant vigour.

Premature losses of leaf area in response to drought and insect herbivory through a leaf lifespan gradient

2021 ◽  
Author(s):  
Sonia Mediavilla ◽  
Montserrat Martínez-Ortega ◽  
Santiago Andrés ◽  
Javier Bobo ◽  
Alfonso Escudero
Keyword(s):  
Leaf Area ◽  
Insect Herbivory ◽  
Leaf Lifespan

scholarly journals How much leaf area do insects eat? A data set of insect herbivory sampled globally with a standardized protocol

Ecology ◽  
2021 ◽  
Author(s):  
Gisele M. Mendes ◽  
Fernando A.O. Silveira ◽  
Carolina Oliveira ◽  
Wesley Dáttilo ◽  
Roger Guevara ◽  
...  
Keyword(s):  
Leaf Area ◽  
Insect Herbivory ◽  
Data Set ◽  
Standardized Protocol

scholarly journals Late-Holocene forest resilience in the central Pyrenean highlands as deduced from pollen analysis of Lake Sant Maurici sediments

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Valentí Rull ◽  
Núria Cañellas-Boltà ◽  
Teresa Vegas-Vilarrúbia
Keyword(s):  
Bronze Age ◽  
Middle Ages ◽  
Iron Age ◽  
Late Holocene ◽  
High Elevation ◽  
Roman Period ◽  
High Mountain ◽  
Southern Central ◽  
Central Pyrenees ◽  
The Middle Ages

Palynological analysis of the last ca. 4300 cal year BP using a sediment core taken from high mountain (ca. 1900 m elevation) Lake Sant Maurici sediments (southern-central Pyrenees) showed remarkable vegetation constancy during the Bronze Age and the Middle Ages. Records of the Iron Age and the Roman period were missing due to a major sedimentary gap. During the studied periods, the vegetation around the lake was largely dominated by pine ( Pinus) forests with birch ( Betula), oak ( Quercus) and hazel ( Corylus) trees, as is the case today. The composition of these forests and the abundance of their components remained quite stable, despite the occurrence of temperature and moisture shifts. The degree of human disturbance, notably that of pastoralism and cereal cultivation by scattered and temporary settlements, was very low and had little or no effect on the dominant forests. This situation contrasts with most high-elevation (subalpine and alpine) environments of the central Pyrenees that were massively anthropized during the Middle Ages. Further research should be aimed at finding sediments corresponding to the Iron Age and the Roman period to verify whether the vegetation constancy can be extended throughout the Late-Holocene. Past records of this type may allow the estimation of natural and anthropogenic thresholds for irreversible forest changes, which would be useful for conservation purposes.

Dispersal of Goeppertia marantifolia clonal offspring increases with greater canopy openness and larger plant size

2017 ◽  
Vol 33 (2) ◽  
pp. 107-113 ◽  
Author(s):  
David P. Matlaga ◽  
Rachel K. Snyder ◽  
Carol C. Horvitz
Keyword(s):  
Leaf Area ◽  
Light Availability ◽  
Plant Size ◽  
Dispersal Distance ◽  
Permanent Plots ◽  
Canopy Openness ◽  
Parent Plant ◽  
Analysis Model ◽  
Corcovado National Park ◽  
Positive Effect

Abstract:Many plants within the neotropical understorey produce both seeds and clonal offspring. Plant attributes (i.e. size) and variability in light can influence seed dispersal but it is not known if these factors influence the dispersal of clonal offspring. Our goal was to determine if canopy openness and plant size influence clonal-offspring dispersal of the herb Goeppertia marantifolia, which produces clonal bulbils on above-ground shoots. We monitored plants in permanent plots with varying levels of canopy openness in Corcovado National Park, Costa Rica. We recorded canopy openness, leaf area and the distance clonal offspring travelled from their parent plant (N = 283). Our path analysis model demonstrated that canopy openness had a strong positive effect on dispersal distance, while the association between clonal-offspring dispersal distance and parent plant leaf area was only weakly positive. On average, plants experiencing high canopy openness dispersed their clonal offspring further than plants under low canopy openness (124 cm vs. 79 cm, respectively). Contrary to studies on species that utilize rhizomes and stolons for clonal reproduction, we found that in this bulbil-producing species light availability is positively associated with clonal dispersal distance. Therefore, the influence of resource availability on spatial population dynamics of clonal species may be influenced by the species’ growth-form.

Interdisciplinary Approaches to Reconstructing Early Population History in the High Himalayas of Nepal

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Jacqueline Eng ◽  
Mark Aldenderfer
Keyword(s):  
Material Culture ◽  
Cultural Practices ◽  
Interdisciplinary Approach ◽  
High Elevation ◽  
Population History ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Low Frequencies ◽  
Mountain Environments ◽  
Interdisciplinary Approaches

Anthropological research in the high-elevation regions of northwestern Nepal offers insights into the populationhistory of the Himalayan arc through a multi- and interdisciplinary approach that includes not only archaeologicaldata and historic and ethnographic accounts but also genomic, isotopic, and bioarchaeologicaldata, as well as innovative use of thermal niche modeling for paleoclimate reconstruction. Together these linesof evidence have allowed us to address project questions about human settlement into the region, including(1) sources of population movements into high-elevation environments of the Himalayan arc and (2) bioculturaladaptations to high-mountain environments. In this paper we compare research at several communalmortuary sites, each with a rich assemblage of material culture and human burials: Mebrak (400 B.C.–A.D. 50),Kyang (400–175 B.C.), and Samdzong (A.D. 450–650), as well as intriguing insights from finds in the earlier (ca.1250–450 B.C.) sites of Lubrak, Chokhopani, and Rhirhi. Our genomic findings demonstrate population originsfrom the Tibetan plateau, despite South Asian material culture recovered in early sites. Bioarchaeological findingsof low frequencies of non-specific stress and trauma indicate successful biocultural adaptation to highaltitudeconditions of hypoxia, cold, and low resource availability, potentially through buffering from exchangenetworks and local cultural practices, alongside high-altitude selected alleles. An integrative, multidisciplinaryapproach thus offers significantly greater opportunities for developing a more nuanced understanding of thepast processes of migration, settlement, and biocultural adaptation in the region. La investigación antropológica de las alturas del noroeste de Nepal nos proporciona conocimientos de la historiade la población del arco Himalaya a través de un enfoque multidisciplinario e interdisciplinario que incluyeno solamente datos arqueológicos y relatos históricos y etnográficos, sino también datos genómicos, isotópicos,y bioarqueológicos, tanto como uso innovador del modelado del nicho térmico para la reconstrucción paleoclimática.En conjunto, estas líneas de evidencia nos han permitido abordar temas sobre el asentamiento humanade la región, como: (1) los orígenes del movimiento hacia ambientes en las alturas del arco del Himalaya;y (2) las adaptaciones bioculturales necesarias para vivir en las alturas. En este artículo comparamos las investigacionesde varios mortuorios comunales que ofrecen conjuntos abundantes de entierros humanos y artefactosrelacionados: Mebrak (400 a.C.–d.C. 50), Kyang (400–175 a.C.), and Samdzong (d.C. 450–650), así como loshallazgos intrigantes de sitios anteriores (ca. 1250–450 a.C.) de Lubrak, Chokhopani, y Rhirhi. Nuestros datosgenómicos sugieren orígenes de le población del altiplano tibetano, a pesar del material que deriva del sur de Asia que se ha recuperado de los sitios mas tempranos. Los hallazgos bioarqueológicos demuestran niveles bajosde estrés y trauma inespecífico, y sugieren éxito en adaptación biocultural, a pesar de las condiciones de hipoxia,frio, y los recursos escasos en este ambiente. Es posible que alelos seleccionados a las alturas, junto con sistemasde intercambio y las costumbres locales contribuyeron al éxito de la adaptación. Por lo tanto, un enfoque multidisciplinarioque integra todas las evidencias ofrece una comprensión mas detallada de los procesos de migración,asentamiento, y adaptación biocultural de la región.

scholarly journals Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

2010 ◽  
Vol 67 (6) ◽  
pp. 624-632 ◽  
Author(s):  
Keila Rego Mendes ◽  
Ricardo Antonio Marenco
Keyword(s):  
Gas Exchange ◽  
Nitrogen Content ◽  
Leaf Area ◽  
Tree Species ◽  
Leaf Traits ◽  
Leaf Nitrogen ◽  
Dry Season ◽  
Leaf Thickness ◽  
Rainfall Regime ◽  
Leaf Nitrogen Content

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

Elevational gradients of bryophyte diversity, life forms, and community assemblage in the southern Appalachian Mountains

2010 ◽  
Vol 40 (11) ◽  
pp. 2164-2174 ◽  
Author(s):  
Sarah E. Stehn ◽  
Christopher R. Webster ◽  
Janice M. Glime ◽  
Michael A. Jenkins
Keyword(s):  
Community Composition ◽  
Elevation Gradient ◽  
Light Availability ◽  
Basal Area ◽  
Life Forms ◽  
High Elevation ◽  
Canopy Openness ◽  
Fine Scale ◽  
Elevational Gradients ◽  
Community Assemblage

We investigated the influence of fine-scale elevational gradients and overstory disturbance on bryophyte distribution, diversity, and community composition. Bryophyte species cover and richness were sampled across 60 randomly selected plots within high-elevation spruce–fir ( Picea – Abies ) forests of Great Smoky Mountains National Park. Ordination and regression analyses revealed a fine-scale elevation gradient (700 m) in bryophyte community composition. Observed changes in bryophyte diversity and community composition were also associated with variation in deciduous basal area and thus litter composition, the prevalence of herbaceous plants, and the degree of canopy openness resulting from balsam woolly adelgid ( Adelges piceae Ratz.) infestation. Although overstory disturbances, such as those caused by the adelgid, create suitable substrate for bryophyte colonization, the corresponding increase in light availability and deciduous basal area may alter bryophyte diversity and community assemblages.

IV.—The Absence of Glacial Phenomena in large Parts of Western Asia and Eastern Europe, Etc

1892 ◽  
Vol 9 (2) ◽  
pp. 54-64
Author(s):  
Henry H. Howorth
Keyword(s):  
Eastern Europe ◽  
New World ◽  
High Elevation ◽  
High Mountain ◽  
Glacial Period ◽  
Altai Mountains ◽  
Western Asia ◽  
Interesting Area ◽  
Geological Magazine

In some papers which you have done me the favour to print in the GEOLOGICAL MAGAZINE, I have endeavoured to apply a new touchstone to test the age of high mountain chains and of land of high elevation, namely, the presence or absence of distinct and prominent traces of former glaciation, and I have argued that where such traces are not forthcoming in a very unmistakable manner, we are justified in concluding that these highlands have been elevated since the so-called Glacial Period. I have endeavoured to apply the touchstone in question to the Ural and Altai Mountains, to the Thian Shan and Himalaya ranges in Asia, and to the great Cordillera which binds together the two continents forming the New World. I wish to make my survey more complete by an examination of an interesting area comprising Eastern Europe and South Western Asia.

scholarly journals Does insect herbivory suppress ecosystem productivity? Evidence from a temperate woodland

2021 ◽  
Author(s):  
Kristiina Visakorpi ◽  
Sofia Gripenberg ◽  
Yadvinder Malhi ◽  
Terhi Riutta
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Leaf Gas Exchange ◽  
Insect Herbivory ◽  
Ecosystem Productivity ◽  
Area Loss ◽  
Leaf Area Loss ◽  
The Relationship

AbstractOur current understanding of the relationship between insect herbivory and ecosystem productivity is limited. Previous studies have typically quantified only leaf area loss, or have been conducted during outbreak years. These set-ups often ignore the physiological changes taking place in the remaining plant tissue after insect attack, or may not represent typical, non-outbreak herbivore densities. Here, we estimate the amount of carbon lost to insect herbivory in a temperate deciduous woodland both through leaf area loss and, notably, through changes in leaf gas exchange in non-consumed leaves under non-outbreak densities of insects. We calculate how net primary productivity changes with decreasing and increasing levels of herbivory, and estimate what proportion of the carbon involved in the leaf area loss is transferred further in the food web. We estimate that the net primary productivity of an oak stand under ambient levels of herbivory is 54 - 69% lower than that of a completely intact stand. The effect of herbivory quantified only as leaf area loss (0.1 Mg C ha−1 yr−1) is considerably smaller than when the effects of herbivory on leaf physiology are included (8.5 Mg C ha−1 yr−1). We propose that the effect of herbivory on primary productivity is non-linear and mainly determined by changes in leaf gas exchange. We call for replicated studies in other systems to validate the relationship between insect herbivory and ecosystem productivity described here.

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