Turnover of Lecanoroid Mycobionts and Their Trebouxia Photobionts Along an Elevation Gradient in Bolivia Highlights the Role of Environment in Structuring the Lichen Symbiosis

Shifts in climate along elevation gradients structure mycobiont–photobiont associations in lichens. We obtained mycobiont (lecanoroid Lecanoraceae) and photobiont (Trebouxia alga) DNA sequences from 89 lichen thalli collected in Bolivia from a ca. 4,700 m elevation gradient encompassing diverse natural communities and environmental conditions. The molecular dataset included six mycobiont loci (ITS, nrLSU, mtSSU, RPB1, RPB2, and MCM7) and two photobiont loci (ITS, rbcL); we designed new primers to amplify Lecanoraceae RPB1 and RPB2 with a nested PCR approach. Mycobionts belonged to Lecanora s.lat., Bryonora, Myriolecis, Protoparmeliopsis, the “Lecanora” polytropa group, and the “L.” saligna group. All of these clades except for Lecanora s.lat. occurred only at high elevation. No single species of Lecanoraceae was present along the entire elevation gradient, and individual clades were restricted to a subset of the gradient. Most Lecanoraceae samples represent species which have not previously been sequenced. Trebouxia clade C, which has not previously been recorded in association with species of Lecanoraceae, predominates at low- to mid-elevation sites. Photobionts from Trebouxia clade I occur at the upper extent of mid-elevation forest and at some open, high-elevation sites, while Trebouxia clades A and S dominate open habitats at high elevation. We did not find Trebouxia clade D. Several putative new species were found in Trebouxia clades A, C, and I. These included one putative species in clade A associated with Myriolecis species growing on limestone at high elevation and a novel lineage sister to the rest of clade C associated with Lecanora on bark in low-elevation grassland. Three different kinds of photobiont switching were observed, with certain mycobiont species associating with Trebouxia from different major clades, species within a major clade, or haplotypes within a species. Lecanoraceae mycobionts and Trebouxia photobionts exhibit species turnover along the elevation gradient, but with each partner having a different elevation threshold at which the community shifts completely. A phylogenetically defined sampling of a single diverse family of lichen-forming fungi may be sufficient to document regional patterns of Trebouxia diversity and distribution.

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Elevation Gradient Altered Soil C, N, and P Stoichiometry of Pinus taiwanensis Forest on Daiyun Mountain

Forests ◽

10.3390/f10121089 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1089

Author(s):

Lan Jiang ◽

Zhongsheng He ◽

Jinfu Liu ◽

Cong Xing ◽

Xinguang Gu ◽

...

Keyword(s):

Elevation Gradient ◽

C:N Ratio ◽

Phosphate Fertilizer ◽

High Elevation ◽

Driving Factors ◽

Slope Position ◽

Elevation Gradients ◽

Soil C ◽

Soil P ◽

C And N

Researches focused on soil carbon (C), nitrogen (N), and phosphorus (P) content and the stoichiometry characteristics along elevation gradients are important for effective management of forest ecosystems. Taking the soil of different elevations from 900 to 1700 m on Daiyun Mountain as the object, the elevation distribution of total C, N, and P in soil and their stoichiometry characteristics were studied. Also, the driving factors resulting in the spatial heterogeneity of soil stoichiometry are presented. The results show the following: (1) The average soil C and N content was 53.03 g·kg−1 and 3.82 g·kg−1, respectively. The content of C and N at high elevation was higher than that of at low elevation. Soil phosphorus fluctuated with elevation. (2) With increasing elevation, soil C:N ratio increased initially to 17.40 at elevation between 900–1000 m, and then decreased to 12.02 at elevation 1600 m. The changing trends of C:P and N:P were similar, and they all fluctuated with elevation. (3) Elevation, soil bulk density, and soil temperature were the main factors influencing the variation of soil C, N, and C:N. Soil pH and slope position were the driving factors for soil P, C:P, and N:P. The soil is rich in C and N, and has less total phosphorus on Daiyun Mountain. Raising the level of phosphate fertilizer appropriately can help to improve soil fertility and promote plant growth as well. In light of this information, in the near future, it will be necessary to conduct separation management of C, N, and P with regular monitoring systems to maintain favorable conditions for soil.

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Untangling cryptic diversity in the High Andes: Revision of the Scytalopus [magellanicus] complex (Rhinocryptidae) in Peru reveals three new species

The Auk ◽

10.1093/auk/ukaa003 ◽

2020 ◽

Vol 137 (2) ◽

Cited By ~ 4

Author(s):

Niels K Krabbe ◽

Thomas S Schulenberg ◽

Peter A Hosner ◽

Kenneth V Rosenberg ◽

Tristan J Davis ◽

...

Keyword(s):

New Species ◽

Dna Sequences ◽

Species Turnover ◽

High Elevation ◽

Species Limits ◽

Peruvian Andes ◽

Tropical Mountains ◽

Avian Biodiversity ◽

Three New Species ◽

Diverse Data

Abstract Tropical mountains feature marked species turnover along elevational gradients and across complex topography, resulting in great concentrations of avian biodiversity. In these landscapes, particularly among morphologically conserved and difficult to observe avian groups, species limits still require clarification. One such lineage is Scytalopus tapaculos, which are among the morphologically most conserved birds. Attention to their distinctive vocal repertoires and phylogenetic relationships has resulted in a proliferation of newly identified species, many of which are restricted range endemics. Here, we present a revised taxonomy and identify species limits among high-elevation populations of Scytalopus tapaculos inhabiting the Peruvian Andes. We employ an integrated framework using a combination of vocal information, mitochondrial DNA sequences, and appearance, gathered from our own fieldwork over the past 40 yr and supplemented with community-shared birdsong archives and museum specimens. We describe 3 new species endemic to Peru. Within all 3 of these species there is genetic differentiation, which in 2 species is mirrored by subtle geographic plumage and vocal variation. In a fourth species, Scytalopus schulenbergi, we document deep genetic divergence and plumage differences despite overall vocal similarity. We further propose that an extralimital taxon, Scytalopus opacus androstictus, be elevated to species rank, based on a diagnostic vocal character. Our results demonstrate that basic exploration and descriptive work using diverse data sources continues to identify new species of birds, particularly in tropical environs.

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Patterns of floral allocation along an elevation gradient: variation in Senecio subalpinus growing in the Tatra Mountains

Alpine Botany ◽

10.1007/s00035-021-00247-w ◽

2021 ◽

Vol 131 (1) ◽

pp. 117-124

Author(s):

Piotr Kiełtyk

Keyword(s):

Elevation Gradient ◽

High Elevation ◽

Tatra Mountains ◽

Ecological Gradient ◽

Elevation Gradients ◽

Allocation Patterns ◽

Abiotic And Biotic Factors ◽

Elevational Shift ◽

The Tatra Mountains ◽

Gradient Variation

AbstractThis study examined the morphological variation in Senecio subalpinus W.D.J. Koch. (Asteraceae) along a 950-m elevation gradient in the Tatra Mountains, Central Europe, with emphasis on floral allocation patterns. Fifteen morphological traits were measured in 200 plants collected in the field from 20 sites then the findings were modelled by elevation using linear mixed-effects models. Plant aboveground biomass and height decreased steadily with increasing elevation; however, the most distinctive feature was the elevational shift in floral allocation patterns. Low-elevation plants had greater numbers of smaller flower heads with a lower overall number of flowers, while high-elevation plants had smaller numbers of bigger flower heads and a greater overall number of flowers. Accordingly, the mean individual flower mass increased significantly with increasing elevation. Interestingly, the width of the outer ligulate flowers also increased considerably with increasing elevation, increasing the fill of the overall circumference of the flower head. Results of this study confirmed that elevation is an important ecological gradient driving variation in vegetative and floral traits of S. subalpinus. Possible causes of the observed variations are subsequently discussed, including the varying effects of both abiotic and biotic factors with elevation gradients.

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Species richness and β-diversity patterns of macrolichens along elevation gradients across the Himalayan Arc

Scientific Reports ◽

10.1038/s41598-021-99675-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Subzar Ahmad Nanda ◽

Manzoor-ul Haq ◽

S. P. Singh ◽

Zafar A. Reshi ◽

Ranbeer S. Rawal ◽

...

Keyword(s):

Species Richness ◽

Species Turnover ◽

Elevation Gradient ◽

Conservation Strategies ◽

Elevational Gradients ◽

Elevation Gradients ◽

Diversity Patterns ◽

Β Diversity ◽

Shaped Pattern ◽

The Himalaya

AbstractUnderstanding the species richness and β-diversity patterns along elevation gradients can aid in formulating effective conservation strategies particularly in areas where local anthropogenic stresses and climate change are quite significant as in the Himalaya. Thus, we studied macrolichen richness and β-diversity along elevational gradients at three sites, namely Kashmir (2200 to 3800 m a.m.s.l), Uttarakhand (2000–3700 m a.m.s.l) and Sikkim (1700 to 4000 m a.m.s.l) which cover much of the Indian Himalayan Arc. In all, 245 macrolichen species belonging to 77 genera and 26 families were collected from the three sites. Only 11 species, 20 genera and 11 families were common among the three transects. Despite the differences in species composition, the dominant functional groups in the three sites were the same: foliose, fruticose and corticolous forms. The hump-shaped elevation pattern in species richness was exhibited by most of the lichen groups, though an inverse hump-shaped pattern was also observed in certain cases. β-diversity (βsor) based on all pairs of comparisons along an elevation gradient varied from 0.48 to 0.58 in Kashmir, 0.03 to 0.63 in Uttarakhand and 0.46 to 0.77 in Sikkim. The contribution of turnover to β-diversity was more than nestedness at all the three transects. Along elevation β-diversity and its components of turnover and nestedness varied significantly with elevation. While species turnover increased significantly along the elevation in all the three transects, nestedness decreased significantly in Kashmir and Sikkim transects but increased significantly in the Uttarakhand transect. Except for the Kashmir Himalayan elevation transect, stepwise β-diversity and its components of turnover and nestedness did not vary significantly with elevation. The present study, the first of its kind in the Himalayan region, clearly brings out that macrolichen species richness, β-diversity, and its components of turnover and nestedness vary along the elevation gradients across the Himalayan Arc. It also highlights that contribution of turnover to β-diversity is higher in comparison to nestedness at all the three transects. The variations in species richness and diversity along elevation gradients underpin the importance of considering elevational gradients in planning conservation strategies.

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Variation in ant-mediated seed dispersal along elevation gradients

10.7287/peerj.preprints.26783 ◽

2018 ◽

Author(s):

Israel Del Toro ◽

Relena R Ribbons

Keyword(s):

Seed Dispersal ◽

Elevation Gradient ◽

High Elevation ◽

Seed Removal ◽

Species Identity ◽

Insect Communities ◽

Removal Rates ◽

Elevation Gradients ◽

Ant Community ◽

Lower Elevation

Ant-mediated seed dispersal, also known as myrmecochory, is a widespread and important mutualism that structures both plant and insect communities. However the extent to which myrmecochory is driven by abiotic and biotic environmental factors remains unclear. We used a replicated standardized seed removal experiment along elevation gradients in four mountain ranges in the southwestern United States to test predictions that: (1) seed removal rates would be greater at lower elevations, and (2) seed species identity influences seed removal rates, (i.e. seeds from their native elevation range would be removed at higher rates than seeds outside of their range). Both predictions were supported. Seed removal rates were ~25% higher at lower elevation sites than at higher elevation sites. The low elevation Datura and high elevation Iris were removed at higher rates in their respective native ranges. We attribute observed differences in dispersal rates to changes in ant community composition, functional diversity, and abundance, suggesting that temperature variation along the elevation gradient.

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Differential phenotypic and genetic expression of defence compounds in a plant–herbivore interaction along elevation

Royal Society Open Science ◽

10.1098/rsos.160226 ◽

2016 ◽

Vol 3 (9) ◽

pp. 160226 ◽

Cited By ~ 5

Author(s):

Ana L. Salgado ◽

Tomasz Suchan ◽

Loïc Pellissier ◽

Sergio Rasmann ◽

Anne-Lyse Ducrest ◽

...

Keyword(s):

Gene Expression ◽

Host Plant ◽

De Novo ◽

Alternative Hypothesis ◽

Elevation Gradient ◽

High Elevation ◽

Elevation Gradients ◽

Tissue Replacement ◽

Plant Herbivore ◽

Optimal Defence

Elevation gradients impose large differences in abiotic and biotic conditions over short distances, in turn, likely driving differences in gene expression more than would genetic variation per se , as natural selection and drift are less likely to fix alleles at such a narrow spatial scale. As elevation increases, the pressure exerted on plants by herbivores and on arthropod herbivores by predators decreases, and organisms spanning the elevation gradient are thus expected to show lower levels of defence at high elevation. The alternative hypothesis, based on the optimal defence theory, is that defence allocation should be higher in low-resource habitats such as those at high elevation, due to higher costs associated with tissue replacement. In this study, we analyse variation with elevation in (i) defence compound content in the plant Lotus corniculatus and (ii) gene expression associated with defence against predators in the specific phytophagous moth, Zygaena filipendulae . Both species produce cyanogenic glycosides (CNglcs) such as lotaustralin and linamarin as defence mechanisms, with the moth, in addition, being able to sequester CNglcs from its host plant. Specifically, we tested the assumption that the defence-associated phenotype in plants and the gene expression in the insect herbivore should covary between low- and high-elevation environments. We found that L. corniculatus accumulated more CNglcs at high elevation, a result in agreement with the optimal defence theory. By contrast, we found that the levels of expression in the defence genes of Z. filipendulae larvae were not related to the CNglc content of their host plant. Overall, expression levels were not correlated with elevation either, with the exception of the UGT33A1 gene, which showed a marginally significant trend towards higher expression at high elevation when using a simple statistical framework. These results suggest that the defence phenotype of plants against herbivores, and subsequent herbivore sequestration machineries and de novo production, are based on a complex network of interactions.

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Climate Sensitivity of Tropical Trees Along an Elevation Gradient in Rwanda

Forests ◽

10.3390/f9100647 ◽

2018 ◽

Vol 9 (10) ◽

pp. 647 ◽

Cited By ~ 1

Author(s):

Myriam Mujawamariya ◽

Aloysie Manishimwe ◽

Bonaventure Ntirugulirwa ◽

Etienne Zibera ◽

Daniel Ganszky ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Climate Sensitivity ◽

Elevation Gradient ◽

High Elevation ◽

Dry Season ◽

Nutrient Ratios ◽

Wet Season ◽

Elevation Gradients ◽

Use Efficiency

Elevation gradients offer excellent opportunities to explore the climate sensitivity of vegetation. Here, we investigated elevation patterns of structural, chemical, and physiological traits in tropical tree species along a 1700–2700 m elevation gradient in Rwanda, central Africa. Two early-successional (Polyscias fulva, Macaranga kilimandscharica) and two late-successional (Syzygium guineense, Carapa grandiflora) species that are abundant in the area and present along the entire gradient were investigated. We found that elevation patterns in leaf stomatal conductance (gs), transpiration (E), net photosynthesis (An), and water-use efficiency were highly season-dependent. In the wet season, there was no clear variation in gs or An with elevation, while E was lower at cooler high-elevation sites. In the dry season, gs, An, and E were all lower at drier low elevation sites. The leaf-to-air temperature difference was smallest in P. fulva, which also had the highest gs and E. Water-use efficiency (An/E) increased with elevation in the wet season, but not in the dry season. Leaf nutrient ratios indicated that trees at all sites are mostly P limited and the N:P ratio did not decrease with increasing elevation. Our finding of strongly decreased gas exchange at lower sites in the dry season suggests that both transpiration and primary production would decline in a climate with more pronounced dry periods. Furthermore, we showed that N limitation does not increase with elevation in the forests studied, as otherwise most commonly reported for tropical montane forests.

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The recent colonization history of the most widespread Podocarpus tree species in Afromontane forests

Annals of Botany ◽

10.1093/aob/mcaa049 ◽

2020 ◽

Vol 126 (1) ◽

pp. 73-83

Author(s):

Jérémy Migliore ◽

Anne-Marie Lézine ◽

Olivier J Hardy

Keyword(s):

Dna Sequences ◽

Demographic History ◽

Central Africa ◽

Single Species ◽

High Elevation ◽

Nuclear Ribosomal Dna ◽

Afromontane Forests ◽

Wide Range ◽

History Of ◽

Sub Saharan

Abstract Background and Aims Afromontane forests host a unique biodiversity distributed in isolated high-elevation habitats within a matrix of rain forests or savannahs, yet they share a remarkable flora that raises questions about past connectivity between currently isolated forests. Here, we focused on the Podocarpus latifolius–P. milanjianus complex (Podocarpaceae), the most widely distributed conifers throughout sub-Saharan African highlands, to infer its demographic history from genetic data. Methods We sequenced the whole plastid genome, mitochondrial DNA regions and nuclear ribosomal DNA of 88 samples from Cameroon to Angola in western Central Africa and from Kenya to the Cape region in eastern and southern Africa to reconstruct time-calibrated phylogenies and perform demographic inferences. Key Results We show that P. latifolius and P. milanjianus form a single species, whose lineages diverged during the Pleistocene, mostly between approx, 200 000 and 300 000 years BP, after which they underwent a wide range expansion leading to their current distributions. Confronting phylogenomic and palaeoecological data, we argue that the species originated in East Africa and reached the highlands of the Atlantic side of Africa through two probable latitudinal migration corridors: a northern one towards the Cameroon volcanic line, and a southern one towards Angola. Although the species is now rare in large parts of its range, no demographic decline was detected, probably because it occurred too recently to have left a genetic signature in our DNA sequences. Conclusions Despite the ancient and highly fluctuating history of podocarps in Africa revealed by palaeobotanical records, the extended distribution of current P. latifolius/milanjianus lineages is shown to result from a more recent history, mostly during the mid-late Pleistocene, when Afromontane forests were once far more widespread and continuous.

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Variation in ant-mediated seed dispersal along elevation gradients

PeerJ ◽

10.7717/peerj.6686 ◽

2019 ◽

Vol 7 ◽

pp. e6686 ◽

Cited By ~ 1

Author(s):

Israel Del Toro ◽

Relena R. Ribbons

Keyword(s):

Seed Dispersal ◽

Environmental Gradients ◽

Elevation Gradient ◽

High Elevation ◽

Seed Removal ◽

Species Identity ◽

Removal Rates ◽

Ant Communities ◽

Elevation Gradients ◽

Elevation Range

Ant-mediated seed dispersal, also known as myrmecochory, is a widespread and important mutualism that structures both plant and ant communities. However, the extent to which ant functional types (e.g., granivorous generalists vs. myrmecochorous ants) across environmental gradients affect seed removal rates is not fully understood. We used a replicated, standardized seed removal experiment along elevation gradients in four mountain ranges in the southwestern United States to test predictions that: (1) seed removal rates would be greater at lower elevations, and (2) seed species identity influences seed removal rates (i.e., seeds from their native elevation range would be removed at higher rates than seeds outside of their native elevation range). Both predictions were supported. Seed removal rates were ∼25% higher at lower elevation sites than at higher elevation sites. The low elevation Datura and high elevation Iris were removed at higher rates in their respective native ranges. We attribute observed differences in dispersal rates to changes in ant community composition, functional diversity, and abundance. We also suggest that temperature variation along the elevation gradient may explain these differences in seed removal rates.

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