scholarly journals Avian community structure and habitat use of Polylepis forests along an elevation gradient

2016 ◽  
Author(s):  
C Steven Sevillano-Rios ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Bird Diversity ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations

Background. As one of the highest and most unique systems in the world, Polylepis forests are recognized both as center of endemism and diversity along the Andes and as a system under serious threat from human activities, fragmentation, and climate change. Effective conservation efforts are limited, in part, by our poor understanding of the habitat needs of the system’s flora and fauna. Methods. In 2014-2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. Birds were surveyed in dry (May-August) and wet (January-April) seasons at 130 points distributed along an elevational gradient (3,300-4,700 masl) and analyzed using Canonical Correspondence Analysis (CCA). Results. A total of 50 species of birds, including 13 species of high conservation concern, were associated with four basic habitat types: (1) Polylepis sericea forests at low elevations, (2) P. weberbaueri forests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Poospiza alticola) were strongly associated with large forest patches (~10-ha) dominated by P. sericea at lower elevations (<3,800 masl), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests of P. weberbaueri at upper elevations (>4,200 masl). Discussion. Results suggest that, in addition to conserving large (>10-ha) P. sericea forests at lower elevations as the cornerstone for maintaining bird diversity, any high elevation (>4,200 masl) relicts of P. weberbaueri, irrespective of size, should be prioritized for conservation.

scholarly journals Avian community structure and habitat use of Polylepis forests along an elevation gradient

2016 ◽  
Author(s):  
C Steven Sevillano-Rios ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Bird Diversity ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations

Background. As one of the highest and most unique systems in the world, Polylepis forests are recognized both as center of endemism and diversity along the Andes and as a system under serious threat from human activities, fragmentation, and climate change. Effective conservation efforts are limited, in part, by our poor understanding of the habitat needs of the system’s flora and fauna. Methods. In 2014-2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. Birds were surveyed in dry (May-August) and wet (January-April) seasons at 130 points distributed along an elevational gradient (3,300-4,700 masl) and analyzed using Canonical Correspondence Analysis (CCA). Results. A total of 50 species of birds, including 13 species of high conservation concern, were associated with four basic habitat types: (1) Polylepis sericea forests at low elevations, (2) P. weberbaueri forests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Poospiza alticola) were strongly associated with large forest patches (~10-ha) dominated by P. sericea at lower elevations (<3,800 masl), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests of P. weberbaueri at upper elevations (>4,200 masl). Discussion. Results suggest that, in addition to conserving large (>10-ha) P. sericea forests at lower elevations as the cornerstone for maintaining bird diversity, any high elevation (>4,200 masl) relicts of P. weberbaueri, irrespective of size, should be prioritized for conservation.

scholarly journals Avian community structure and habitat use ofPolylepisforests along an elevation gradient

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3220 ◽  
Author(s):  
C. Steven Sevillano-Ríos ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations ◽  
Avian Community Structure ◽  
Landscape Attributes

BackgroundAs one of the highest forest ecosystems in the world,Polylepisforests are recognized both as center of endemism and diversity along the Andes and as an ecosystem under serious threat from habitat loss, fragmentation, and climate change due to human activities. Effective conservation efforts are limited, in part, by our poor understanding of the ecology and habitat needs of the ecosystem’s flora and fauna.MethodsIn 2014–2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. We surveyed birds during the dry (May–August) and wet (January–April) seasons at 130 points distributed along an elevational gradient (3,300–4,700 m) and analyzed our data using Canonical Correspondence Analysis (CCA).ResultsWe associated a total of 50 species of birds, including 13 species of high conservation concern, with four basic habitat types: (1)Polylepis sericeaforests at low elevations, (2)P. weberbaueriforests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Microspingus alticola) were strongly associated with large forest patches (∼10-ha) ofP. sericeaat lower elevations (<3,800 m), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests ofP. weberbaueriat higher elevations (>4,200 m).DiscussionResults suggest two key strategies form the cornerstones of conservation efforts: (a) protect large remnant (>10-ha)P. sericeaforests at lower elevations and (b) maintain all relicts ofP. weberbaueri, irrespective of size, at high elevations (>4,200 m).

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 The Within-Population Formation of the Upper Range Limit in a Songbird

2021 ◽  
Author(s):  
Martin Grüebler ◽  
Johann von Hirschheydt ◽  
Fränzi Korner-Nievergelt
Keyword(s):  
Environmental Gradients ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limit ◽  
Apparent Survival ◽  
Breeding Sites ◽  
Factors Affecting ◽  
Mobile Species ◽  
Random Dispersal ◽  
High Elevations

Abstract The formation of the upper distributional range limit of species at mountain slopes is often based on environmental gradients resulting in changing demographic rates towards high elevations. However, we still lack an empiric 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 lower elevations 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 Odonata (Insecta) communities along an elevational gradient in the Atlantic forest of southeastern Brazil, with the description of the female of Heteragrion mantiqueirae Machado, 2006

2021 ◽  
Vol 24 ◽  
pp. 178-196
Author(s):  
G. Stefani-Santos ◽  
W.F. Ávila Jr ◽  
M.A. Clemente ◽  
N.R. Henriques ◽  
A.S.B. Souza ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Elevational Gradient ◽  
High Elevation ◽  
Minas Gerais ◽  
Southeastern Brazil ◽  
Lack Of Information ◽  
Minas Gerais State ◽  
Environmental Protection Area ◽  
Protection Area ◽  
High Elevations

Despite the important role of the order Odonata in ecosystems, there is a lack of information about dragonfly communities in several regions, high elevation sites, and environmentally protected areas in Minas Gerais State, Brazil. Our objective was to assess the abundance and richness of dragonfly and damselfly communities along an elevational gradient in the Atlantic Forest,southeastern Brazil. This study was conducted in the Fernão Dias Environmental Protection Area,Mantiqueira Mountain region, Gonçalves, Minas Gerais State, in sites covered by Seasonal Semideciduous and mixed forests. This is the first study of Odonata communities in the region. Samplings were carried out on 17 days from October 2019 to March 2020 at three elevation ranges (low,mid, and high). A total of 293 specimens, distributed in 39 species and 9 families, were sampled. Elevation did not influence the richness or abundance of dragonflies but altered community composition. Some species were found to be exclusive to high-elevation sites, such as Heteragrion mantiqueirae Machado, 2006, which was recorded for the first time in Minas Gerais and we provide a description and diagnosis of the single female collected in tandem. A novel species of the genus Brechmorhoga was found to occur at mid and high elevations. The composition of dragonfly communities depends on the degree of preservation and extension of forest areas. Therefore, conservation of forests in Gonçalves is crucial for preserving Odonata diversity in Minas Gerais State.

scholarly journals Life-history characteristics influence physiological strategies to cope with hypoxia in Himalayan birds

2016 ◽  
Vol 283 (1843) ◽  
pp. 20162201 ◽  
Author(s):  
S. Barve ◽  
A. A. Dhondt ◽  
V. B. Mathur ◽  
Z. A. Cheviron
Keyword(s):  
Life Histories ◽  
Haemoglobin Concentration ◽  
Elevational Gradient ◽  
High Elevation ◽  
Blood Oxygen ◽  
Migration Patterns ◽  
Migratory Patterns ◽  
Physiological Stressor ◽  
Migratory Strategy ◽  
High Elevations

Hypobaric hypoxia at high elevation represents an important physiological stressor for montane organisms, but optimal physiological strategies to cope with hypoxia may vary among species with different life histories. Montane birds exhibit a range of migration patterns; elevational migrants breed at high elevations but winter at low elevations or migrate further south, while high-elevation residents inhabit the same elevation throughout the year. Optimal physiological strategies to cope with hypoxia might therefore differ between species that exhibit these two migratory patterns, because they differ in the amount time spent at high elevation. We examined physiological parameters associated with blood-oxygen transport (haemoglobin concentration and haematocrit, i.e. the proportion of red blood cells in blood) in nine species of elevational migrants and six species of high-elevation residents that were sampled along a 2200 m (1000–3200 m) elevational gradient. Haemoglobin concentration increased with elevation within species regardless of migratory strategy, but it was only significantly correlated with haematocrit in elevational migrants. Surprisingly, haemoglobin concentration was not correlated with haematocrit in high-elevation residents, and these species exhibited higher mean cellular haemoglobin concentration than elevational migrants. Thus, alternative physiological strategies to regulate haemoglobin concentration and blood O 2 carrying capacity appear to differ among birds with different annual elevational movement patterns.

Comparative demography of a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

2006 ◽  
Vol 84 (12) ◽  
pp. 1789-1795 ◽  
Author(s):  
Xin Lu ◽  
Bin Li ◽  
Juan Juan Liang
Keyword(s):  
Life History ◽  
Northern China ◽  
Elevational Gradient ◽  
High Elevation ◽  
Life History Strategies ◽  
Adult Males ◽  
Rana Chensinensis ◽  
Demographic Traits ◽  
Comparative Demography ◽  
High Elevations

Rana chensinensis (David, 1875) is a temperate anuran endemic to northern China. We examined differences in demographic traits of the populations from three elevations (1400, 1700, and 2000 m) along a montane river in 2002. We found that frogs from higher elevations had delayed maturity, a larger size at maturity, and slower growth rates compared with frogs at lower elevations. This life-history model is similar to observations of other amphibians living in montane areas. However, discordance with the expected model occurred between neighboring populations and the variation was sex-specific. Mid-elevation adult males were significantly older and larger than their low-elevation congeners, but they were statistically similar in age and size to frogs from high elevations; females from mid elevations were not statistically different in age and size from females from our low-elevation site, but they were significantly younger and smaller than high-elevation females. These variations may be related to sexual differences in life-history strategies, which might not covary systematically when elevational gradients are set at a finer scale. At each elevation, the sex ratio was skewed towards females; females also matured later, lived longer, and were larger. Age was a major factor related to size, but other factors played a role in shaping size differences both between populations and between sexes.

Tallow tree allocates contrasting secondary chemicals in response to varying environments along elevational gradients

2020 ◽  
Vol 13 (3) ◽  
pp. 295-303
Author(s):  
Li Xiao ◽  
Jialiang Zhang ◽  
Wei Huang ◽  
Juli Carrillo ◽  
Evan Siemann ◽  
...  
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Feeding Guilds ◽  
Ecological Strategies ◽  
Elevational Gradients ◽  
Chinese Tallow ◽  
Tallow Tree ◽  
Secondary Chemicals ◽  
Varying Environments

Abstract Aims Understanding how tree species regulate multiple types of secondary chemicals along elevational gradients is critical for elucidating the physiological and ecological strategies of plants in response to varying biotic and/or abiotic environments. This study aims to examine how Chinese tallow tree (Triadica sebifera) allocates resources to the production of different secondary chemicals in response to varying environments across elevational gradients. Methods We conducted field surveys of different herbivore feeding guilds and their damage rates on Chinese tallow trees along an elevational gradient in China and measured secondary chemicals (tannins and flavonoids) in damaged and undamaged leaves. Important Findings The odds of a leaf being damaged (chewing or scarring) decreased with elevation. Flavonoid concentrations increased with elevation in undamaged leaves but decreased with elevation in damaged leaves, with quercitrin contributing most strongly to this pattern, likely as results of plant responding to changing biotic or abiotic stresses along elevational gradients. Tannin concentrations did not vary with elevation, so undamaged leaves had relatively lower tannin to flavonoid ratios at high elevation than at low elevation. Our study reveals variation in herbivory and contrasting trends in plant secondary metabolism along an elevation gradient and highlights the importance of simultaneously considering multiple types of secondary chemicals in plant physiological and ecological strategies.

scholarly journals Aposematic Coloration of Moths Decreases Strongly along an Elevational Gradient in the Andes

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 903
Author(s):  
Konrad Fiedler ◽  
Gunnar Brehm
Keyword(s):  
Light Trap ◽  
Elevational Gradient ◽  
Montane Forest ◽  
Taxonomic Composition ◽  
Tropical Andes ◽  
Tropical Mountains ◽  
Aposematic Coloration ◽  
The Andes ◽  
High Elevations ◽  
Trap Catches

On tropical mountains, predation pressure decreases with elevation. Accordingly, one expects an elevational decay in the prevalence of costly defensive traits such as aposematic coloration. Using light-trap catches of Arctiinae moths (353 species, 4466 individuals), assembled along a forested gradient in the megadiverse tropical Andes of southern Ecuador, we show that the incidence of aposematic coloration decreases strongly between 1040 and 2670 m asl. While over 60% of Arctiinae moths were warningly colored at lowest sites, this fraction decreased to less than 20% in montane forest, yet increased slightly again at the highest sites in the very open Purdiaea nutans forest. In parallel, the incidence of hymenopteran mimics and of species that mimic chemically defended beetles decreased with elevation. Hymenopteran mimics accounted for less than 5% of Arctiinae moths at sites above 2100 m, and beetle mimics were essentially lacking at high elevations. These patterns coincide with a change in gross taxonomic composition of Arctiinae ensembles and with an increase in average body size towards higher elevations. Representatives of Euchromiina and Ctenuchina became scarce with altitude, whereas the prevalence of Lithosiinae increased. Our findings suggest that the variable selective pressures along the elevational gradient favor warning coloration primarily at lower sites, whereas cryptic appearance of adult moths dominates in the tropical upper montane forest.

scholarly journals Species groups distributed across elevational gradients reveal convergent and continuous genetic adaptation to high elevations

2018 ◽  
Vol 115 (45) ◽  
pp. E10634-E10641 ◽  
Author(s):  
Yan-Bo Sun ◽  
Ting-Ting Fu ◽  
Jie-Qiong Jin ◽  
Robert W. Murphy ◽  
David M. Hillis ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Positive Selection ◽  
Rapid Change ◽  
Elevational Gradient ◽  
High Elevation ◽  
Individual Gene ◽  
Evolutionary Changes ◽  
Species Groups ◽  
The Individual ◽  
High Elevations

Although many cases of genetic adaptations to high elevations have been reported, the processes driving these modifications and the pace of their evolution remain unclear. Many high-elevation adaptations (HEAs) are thought to have arisen in situ as populations rose with growing mountains. In contrast, most high-elevation lineages of the Qinghai-Tibetan Plateau appear to have colonized from low-elevation areas. These lineages provide an opportunity for studying recent HEAs and comparing them with ancestral low-elevation alternatives. Herein, we compare four frogs (three species ofNanoranaand a close lowland relative) and four lizards (Phrynocephalus) that inhabit a range of elevations on or along the slopes of the Qinghai-Tibetan Plateau. The sequential cladogenesis of these species across an elevational gradient allows us to examine the gradual accumulation of HEA at increasing elevations. Many adaptations to high elevations appear to arise gradually and evolve continuously with increasing elevational distributions. Numerous related functions, especially DNA repair and energy metabolism pathways, exhibit rapid change and continuous positive selection with increasing elevations. Although the two studied genera are distantly related, they exhibit numerous convergent evolutionary changes, especially at the functional level. This functional convergence appears to be more extensive than convergence at the individual gene level, although we found 32 homologous genes undergoing positive selection for change in both high-elevation groups. We argue that species groups distributed along a broad elevational gradient provide a more powerful system for testing adaptations to high-elevation environments compared with studies that compare only pairs of high-elevation versus low-elevation species.

Sign in / Sign up

Export Citation Format

Share Document