Geophysical, evolutionary and ecological processes interact to drive phylogenetic dispersion in angiosperm assemblages along the longest elevational gradient in the world

AbstractEcologists have embraced phylogenetic measures of assemblage structure, in large part for the promise of better mechanistic inferences. However, phylogenetic structure is driven by a wide array of factors from local biotic interactions to biogeographical history, complicating the mechanistic interpretation of a pattern. This may be particularly problematic along elevational gradients, where rapidly changing physical and biological conditions overlap with geological and biogeographical history, potentially producing complex patterns of phylogenetic dispersion (relatedness). We focus on the longest elevational gradient of vegetation in the world (i.e. c. 6000 m in Nepal) to explore patterns of phylogenetic dispersion for angiosperms (flowering plants) along this elevational gradient. We used the net relatedness index to quantify phylogenetic dispersion for each elevational band of 100 m. We found a zig-zag pattern of phylogenetic dispersion along this elevational gradient. With increasing elevation, the phylogenetic relatedness of species decreased for the elevational segment between 0 and c. 2100 m, increased for the elevational segment between 2100 and c. 4200 m, and decreased for the elevational segment above c. 4200 m. We consider this pattern to be a result of the interaction of geophysical (e.g. plate tectonics) and eco-evolutionary processes (e.g. niche conservatism and trait convergence). We speculate on the mechanisms that might have generated this zig-zag pattern of phylogenetic dispersion.

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Floral colour structure in two Australian herbaceous communities: it depends on who is looking

Annals of Botany ◽

10.1093/aob/mcz043 ◽

2019 ◽

Vol 124 (2) ◽

pp. 221-232 ◽

Cited By ~ 8

Author(s):

Mani Shrestha ◽

Adrian G Dyer ◽

Jair E Garcia ◽

Martin Burd

Keyword(s):

Flowering Plants ◽

Floral Colour ◽

Random Structure ◽

Phylogenetic Structure ◽

Colour Perception ◽

Phylogenetic Relatedness ◽

Herbaceous Communities ◽

Hymenopteran Species ◽

Complex Landscape ◽

Colour Signals

Abstract Background and Aims Pollinator-mediated interactions between plant species may affect the composition of angiosperm communities. Floral colour signals should play a role in these interactions, but the role will arise from the visual perceptions and behavioural responses of multiple pollinators. Recent advances in the visual sciences can be used to inform our understanding of these perceptions and responses. We outline the application of appropriate visual principles to the analysis of the annual cycle of floral colour structure in two Australian herbaceous communities. Methods We used spectrographic measurements of petal reflectance to determine the location of flowers in a model of hymenopteran colour vision. These representations of colour perception were then translated to a behaviourally relevant metric of colour differences using empirically calibrated colour discrimination functions for four hymenopteran species. We then analysed the pattern of colour similarity in terms of this metric in samples of co-flowering plants over the course of a year. We used the same method to analyse the annual pattern of phylogenetic relatedness of co-flowering plants in order to compare colour structure and phylogenetic structure. Key Results Co-flowering communities at any given date seldom had colour assemblages significantly different from random. Non-random structure, both dispersion and clustering, occurred occasionally, but depended on which bee observer is considered. The degree of colour similarity was unrelated to phylogenetic similarity within a co-flowering community. Conclusions Perceived floral colour structure varied with the sensory capabilities of the observer. The lack of colour structure at most sample dates, particularly the rarity of strong dispersion, suggests that plants do not use chromatic signals primarily to enable bees to discriminate between co-flowering species. It is more likely that colours make plants detectable in a complex landscape.

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Family Legacy: Depicting Diversity-Elevation Relationships of Tropical Tree Communities

10.21203/rs.3.rs-1236838/v1 ◽

2022 ◽

Author(s):

Vitor de Andrade Kamimura ◽

Gabriel Mendes Marcusso ◽

Gabriel Pavan Sabino ◽

Marco Antonio Assis ◽

Carlos Alfredo Joly ◽

...

Keyword(s):

Elevational Gradient ◽

Species Selection ◽

Southeastern Brazil ◽

Tropical Rainforests ◽

Ecological Processes ◽

Phylogenetic Structure ◽

Diversity Pattern ◽

Tree Communities ◽

Fern Species ◽

Unimodal Pattern

Abstract Unveiling the ecological processes driving diversity and its relationship to the environment remains a central goal in ecological studies. Here, we investigated the elevation effect on plant diversity patterns of tropical rainforests, using beta-, phylogenetic and alpha diversities. To do so, we compiled a forest dataset with 22,236 trees (DBH ≥ 4.8 cm) from 17 plots of 1 ha each along an elevational gradient (0 – 1,200 m a.s.l) in the Atlantic Forest of Southeastern Brazil. We found high phylogenetic and species rates of turnover – beta-diversity - along the elevational gradient. Alpha phylodiversity showed a monotonic decrease with increasing elevation, including or not fern species (a distantly related clade usually ignored in tropical ecology studies), while the phylogenetic structure was highly affected by the inclusion of fern trees. Species diversity showed a unimodal pattern for the whole community, and different patterns for the richest families. The diversity pattern of the whole community emerges from differences among species distribution of the richest families, while phylogenetic diversity seems to be gradually filtered by elevation. At intermediate elevations, higher species diversification within families might have led to different strategies and cooccurrence in tropical rainforests. We also showed that intricate effects of elevation in species assemblages can be better assessed using both ecological and evolutionary approaches, stressing the importance of species selection in diversity analyzes. Finally, we demonstrate that elevation has different effects on the species distributions of the richest families and warn that these differences should be considered in conservation planning.

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Meta-analysis reveals severe pollen limitation for the flowering plants growing in East Himalaya-Hengduan Mountains region

BMC Ecology ◽

10.1186/s12898-020-00322-6 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Xianfeng Jiang ◽

Yanping Xie

Keyword(s):

Confidence Interval ◽

Pollen Limitation ◽

Meta Analysis ◽

Flowering Plants ◽

Biodiversity Hotspot ◽

Clear Relationship ◽

Hengduan Mountains ◽

Independent Data ◽

The World ◽

Global Biodiversity

Abstract Background Pollen limitation occurs widely and has an important effect on flowering plants. The East Himalaya-Hengduan Mountains region is a global biodiversity hotspot. However, to our knowledge, no study has synthetically assessed the degree of pollen limitation in this area. The present study aims to reveal the degree of pollen limitation for the flowering plants growing on East Himalaya-Hengduan Mountains and to test whether the reproductive features or the elevation is closely correlated with the degree of pollen limitation in this area. Results We complied data from 76 studies, which included 96 species and 108 independent data records. We found that the flowering plants in this area undergo severe pollen limitation [overall Hedges’ d = 2.004, with a 95% confidence interval (1.3264, 2.6743)] that is much higher than that of the flowering plants growing in many other regions around the world. The degree of pollen limitation was tested to determine the correlation with the capacity for autonomous self-reproduction and with the pollination pattern (generalized vs. specialized pollination) of plants. In addition, we found a clear relationship between elevation and the degree of pollen limitation, which indicates that plants might undergo more severe pollen limitation in relatively high places. Conclusions This paper is the first to address the severe pollen limitation of the flowering plants growing in East Himalaya-Hengduan Mountains region. Moreover, we reveal the positive correlation between elevation and the degree of pollen limitation.

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A global assessment of the potential distribution of naturalized and planted populations of the ornamental alien tree Schinus molle

NeoBiota ◽

10.3897/neobiota.68.68572 ◽

2021 ◽

Vol 68 ◽

pp. 105-126

Author(s):

Jorge E. Ramírez-Albores ◽

David M. Richardson ◽

Valdir M. Stefenon ◽

Gustavo A. Bizama ◽

Marlín Pérez-Suárez ◽

...

Keyword(s):

South Africa ◽

Potential Distribution ◽

Natural Populations ◽

High Survival ◽

Ecological Processes ◽

Coverage Area ◽

Schinus Molle ◽

Novel Approach ◽

The World ◽

Dry Climates

The Peruvian Peppertree (Schinus molle L.) is an evergreen tree native to semiarid environments of Peru and Bolivia in South America. This tree has been introduced and widely planted for ornamental and forestry purposes in several semiarid regions of the world because its seedlings are easily established and have a high survival rate; it also grows quickly, and it is tolerant of dry climates. We compared the global and regional niches of naturalized and planted populations of S. molle in order to examine the invasive stages and potential distribution of this species in four regions of the world. This work provides a novel approach for understanding the invasion dynamics of S. molle in these areas and elucidates the ecological processes that bring about such invasions. Most naturalized and planted populations were found to be in equilibrium with the environment. In its native range as well as in Australia and South Africa the models of the coverage area of habitat suitability for natural populations were the highest, whereas the coverage area of planted populations was lower. For planted populations in Australia and South Africa, a large percentage of predicted presences fell within sink populations. The invasion stages of S. molle vary across regions in its adventive range; this result may be attributable to residence time as well as climatic and anthropic factors that have contributed to the spread of populations.

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The World Flora Online 2020 project: will Cameroon come up to the expectation?

Rodriguésia ◽

10.1590/2175-7860201566403 ◽

2015 ◽

Vol 66 (4) ◽

pp. 961-972 ◽

Cited By ~ 2

Author(s):

Jean Michel Onana

Keyword(s):

Plant Species ◽

Flowering Plants ◽

West African ◽

Tropical Africa ◽

African Countries ◽

Red Data Book ◽

The World ◽

Data Book ◽

Plant Families ◽

High Level

Abstract Biodiverse Cameroon has been highlighted as the top country in tropical Africa for plant species diversity per degree square, with a higher diversity than all other West African countries added together, and including two of the top documented centres of plant diversity in Tropical Africa. Despite its reduced taxonomic capacity, with only six active taxonomists a high level of botanical activity in the country has resulted in accomplishments such as the databasing of the YA Herbarium (over 60,000 records), which has an in-country collection coverage of almost 95% of the known plant species that are recorded for Cameroon. Other accomplishments are the Red Data Book of the Flowering Plants of Cameroon, several local checklists and published volumes of the Flore du Cameroun which covers 37% of the country's species. Currently the checklist of Cameroon records 7,850 taxa at species and infraspecific level. Resources are needed to support and heighten the profile of this small botanical community. Already thanks to strong collaboration between Cameroon and renowned botanical institutes of others countries, in particular France and United Kingdom, one hundred and thirteen plant families have been published and would help this country to complete the recording of its biodiversity towards contributing to the World Flora Online 2020 project.

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Serpentine Plant Assemblages: A Global Overview

Serpentine Geoecology of Western North America ◽

10.1093/oso/9780195165081.003.0015 ◽

2007 ◽

Author(s):

Earl B. Alexander ◽

Roger G. Coleman ◽

Todd Keeler-Wolfe ◽

Susan P. Harrison

Keyword(s):

Fire History ◽

New Caledonia ◽

Physical Factors ◽

Ecological Processes ◽

Global Trends ◽

The World ◽

Serpentine Vegetation ◽

Global Patterns ◽

Plant Assemblages ◽

Local Levels

Serpentine substrates are found in many parts of the world, but there is considerable variation in the structure, composition, and diversity of the flora they support. To place western North America in a worldwide context, this chapter provides a brief sketch of global patterns in serpentine plant life, drawing on the reviews by Brooks (1987), Baker et al. (1992), and Roberts and Proctor (1992), as well as other sources. Following this is an overview of some of the main physical factors known to cause variation in the vegetation on serpentine both at the regional and local levels. Finally, we discuss what is known about the roles of competition, fire, herbivory, and other ecological processes in shaping plant assemblages on serpentine. The availability of botanical information varies considerably around the world. In most countries where serpentine occurs, it is possible to name at least some of the plant species and vegetation types found on it. But in countries where surveys are incomplete, or where information has not been synthesized at a national or larger level, it is generally not possible to estimate the number of serpentine-endemic taxa or to describe patterns of variation within the serpentine vegetation. Indonesia, Malaysia, the Phillippines, and Brazil are particularly notable as countries with serpentine floras that are potentially rich but in need of more study. With this caveat, however, some of the major global trends can be described based on available knowledge. Flora and vegetation of selected parts of the world are summarized in table 10-1, and global contrasts between the vegetation of serpentine and other soils are summarized in table 10-2. New Caledonia and Cuba lead the world in known serpentine endemic diversity with 900+ species each, >90% of which are also endemics to these islands. Depending on elevation, rainfall, and fire history, the serpentine vegetation on both islands varies from sclerophyllous scrubland that contrasts visibly with the neighboring vegetation, to medium-stature rainforest that is not strikingly different in appearance from the vegetation growing in other soils.

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Scale dependence in the phylogenetic relatedness of alien and native taxa

Journal of Plant Ecology ◽

10.1093/jpe/rtaa048 ◽

2020 ◽

Vol 13 (5) ◽

pp. 601-610

Author(s):

Chris M McGrannachan ◽

Gillis J Horner ◽

Melodie A McGeoch

Keyword(s):

Alien Species ◽

Spatial Scale ◽

Native Species ◽

Spatial Scales ◽

Pairwise Distance ◽

Phylogenetic Structure ◽

Phylogenetic Clustering ◽

Phylogenetic Relatedness ◽

Darwin's Naturalization Hypothesis ◽

Darwin’S Naturalization Hypothesis

Abstract Aims Darwin’s naturalization hypothesis proposes that successfully established alien species are less closely related to native species due to differences in their ecological niches. Studies have provided support both for and against this hypothesis. One reason for this is the tendency for phylogenetic clustering between aliens and natives at broad spatial scales with overdispersion at fine scales. However, little is known about how the phylogenetic relatedness of alien species alters the phylogenetic structure of the communities they invade, and at which spatial scales effects may manifest. Here, we examine if invaded understorey plant communities, i.e. containing both native and alien taxa, are phylogenetically clustered or overdispersed, how relatedness changes with spatial scale and how aliens affect phylogenetic patterns in understorey communities. Methods Field surveys were conducted in dry forest understorey communities in south-east Australia at five spatial scales (1, 20, 500, 1500 and 4500 m2). Standardized effect sizes of two metrics were used to quantify phylogenetic relatedness between communities and their alien and native subcommunities, and to examine how phylogenetic patterns change with spatial scale: (i) mean pairwise distance and (ii) mean nearest taxon distance (MNTD). Important Findings Aliens were closely related to each other, and this relatedness tended to increase with scale. Native species and the full community exhibited either no clear pattern of relatedness with increasing spatial scale or were no different from random. At intermediate spatial scales (20–500 m2), the whole community tended towards random whereas the natives were strongly overdispersed and the alien subcommunity strongly clustered. This suggests that invasion by closely related aliens shifts community phylogenetic structure from overdispersed towards random. Aliens and natives were distantly related across spatial scales, supporting Darwin’s naturalization hypothesis, but only when phylogenetic distance was quantified as MNTD. Phylogenetic dissimilarity between aliens and natives increased with spatial scale, counter to expected patterns. Our findings suggest that the strong phylogenetic clustering of aliens is driven by human-mediated introductions involving closely related taxa that can establish and spread successfully. Unexpected scale-dependent patterns of phylogenetic relatedness may result from stochastic processes such as fire and dispersal events and suggest that competition and habitat filtering do not exclusively dominate phylogenetic relationships at fine and coarse spatial scales, respectively. Distinguishing between metrics that focus on different evolutionary depths is important, as different metrics can exhibit different scale-dependent patterns.

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Phylogenetic overdispersion of plant species in southern Brazilian savannas

Brazilian Journal of Biology ◽

10.1590/s1519-69842009000400011 ◽

2009 ◽

Vol 69 (3) ◽

pp. 843-849 ◽

Cited By ~ 6

Author(s):

IA. Silva ◽

MA. Batalha

Keyword(s):

Phylogenetic Relationships ◽

Plant Traits ◽

Environmental Filtering ◽

Southeastern Brazil ◽

Ecological Communities ◽

Ecological Interactions ◽

Ecological Processes ◽

Phylogenetic Structure ◽

History Of ◽

Phylogenetic Overdispersion

Ecological communities are the result of not only present ecological processes, such as competition among species and environmental filtering, but also past and continuing evolutionary processes. Based on these assumptions, we may infer mechanisms of contemporary coexistence from the phylogenetic relationships of the species in a community. We studied the phylogenetic structure of plant communities in four cerrado sites, in southeastern Brazil. We calculated two raw phylogenetic distances among the species sampled. We estimated the phylogenetic structure by comparing the observed phylogenetic distances to the distribution of phylogenetic distances in null communities. We obtained null communities by randomizing the phylogenetic relationships of the regional pool of species. We found a phylogenetic overdispersion of the cerrado species. Phylogenetic overdispersion has several explanations, depending on the phylogenetic history of traits and contemporary ecological interactions. However, based on coexistence models between grasses and trees, density-dependent ecological forces, and the evolutionary history of the cerrado flora, we argue that the phylogenetic overdispersion of cerrado species is predominantly due to competitive interactions, herbivores and pathogen attacks, and ecological speciation. Future studies will need to include information on the phylogenetic history of plant traits.

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Building a Robust, Densely-Sampled Spider Tree of Life for Ecosystem Research

Diversity ◽

10.3390/d12080288 ◽

2020 ◽

Vol 12 (8) ◽

pp. 288

Author(s):

Nuria Macías-Hernández ◽

Marc Domènech ◽

Pedro Cardoso ◽

Brent C. Emerson ◽

Paulo Alexandre Vieira Borges ◽

...

Keyword(s):

Phylogenetic Trees ◽

Phylogenetic Diversity ◽

Dna Barcode ◽

Phylogenetic Reconstruction ◽

Local Communities ◽

Background Information ◽

Ecological Processes ◽

Phylogenetic Structure ◽

Topological Constraint ◽

Ecosystem Research

Phylogenetic relatedness is a key diversity measure for the analysis and understanding of how species and communities evolve across time and space. Understanding the nonrandom loss of species with respect to phylogeny is also essential for better-informed conservation decisions. However, several factors are known to influence phylogenetic reconstruction and, ultimately, phylogenetic diversity metrics. In this study, we empirically tested how some of these factors (topological constraint, taxon sampling, genetic markers and calibration) affect phylogenetic resolution and uncertainty. We built a densely sampled, species-level phylogenetic tree for spiders, combining Sanger sequencing of species from local communities of two biogeographical regions (Iberian Peninsula and Macaronesia) with a taxon-rich backbone matrix of Genbank sequences and a topological constraint derived from recent phylogenomic studies. The resulting tree constitutes the most complete spider phylogeny to date, both in terms of terminals and background information, and may serve as a standard reference for the analysis of phylogenetic diversity patterns at the community level. We then used this tree to investigate how partial data affect phylogenetic reconstruction, phylogenetic diversity estimates and their rankings, and, ultimately, the ecological processes inferred for each community. We found that the incorporation of a single slowly evolving marker (28S) to the DNA barcode sequences from local communities, had the highest impact on tree topology, closely followed by the use of a backbone matrix. The increase in missing data resulting from combining partial sequences from local communities only had a moderate impact on the resulting trees, similar to the difference observed when using topological constraints. Our study further revealed substantial differences in both the phylogenetic structure and diversity rankings of the analyzed communities estimated from the different phylogenetic treatments, especially when using non-ultrametric trees (phylograms) instead of time-stamped trees (chronograms). Finally, we provide some recommendations on reconstructing phylogenetic trees to infer phylogenetic diversity within ecological studies.

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

Diversity ◽

10.3390/d12120456 ◽

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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