We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean ...basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in Lagrange+, a modified version of the ML-based parametric biogeographic program Lagrange. DO is measured in units of "wallaces" (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto–Orinoco–Amazon river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America during the Paleocene–Eocene (ca. 58–45 Ma), potentially during the existence of an incomplete Paleogene Arc (∼59 Ma) or Lesser Antilles Arc (∼45 Ma), but predating the GAARlandia land bridge (∼34–33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) plate margin did not serve as a dispersal corridor until the Late Neogene (12–0 Ma), and contributed relatively little to the formation of modern distributions.
Sticking around Ottaviani, Gianluigi; Méndez-Castro, Francisco E.; Conti, Luisa ...
Diversity & distributions,
09/2022, Letnik:
28, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Aim
Species on islands are at high risk of extinction due to environmental changes, including global warming, land‐use alterations and invasions. At local scales, extinctions can be offset by ...strategies promoting in situ persistence. We explored how persistence‐related traits of plants—that is, linked to belowground resource conservation, growth, size and longevity—on edaphic islands respond to variation in insularity and the environment (soil and microclimate), including intraspecific variability, which is rarely considered in functional island biogeography. We hypothesised that plants facing strong insularity and harsh soil conditions are characterised by enhanced persistence abilities.
Location
Shallow‐soil temperate dry grasslands on granite outcrops, Central Europe.
Methods
We focussed on edaphic island specialist species belonging to different life histories, namely clonal and non‐clonal perennial plants. We used linear and linear mixed‐effect models to examine intra‐ and interspecific trait patterns versus variation in insularity, soil and microclimate.
Results
Insularity tended to promote smaller plants (non‐clonal species) and belowground resource‐conservative strategies (both clonal and non‐clonal species), increasing the likelihood of local persistence. Soil also contributed largely to explaining persistence‐related trait patterns: plants growing in harsh soil conditions tended to be resource conservative. Clonal species are distinguished by highly consistent responses to variation in insularity and soil conditions, whereas non‐clonal plants showed distinct species‐specific responses.
Main conclusions
Our findings have important implications for the conservation biogeography of edaphic island plant specialists. Clonal species may be susceptible to local extinction should insularity or soil conditions vary, for example, due to abrupt changes in the geographical setting (e.g. habitat loss) or local environmental factors (e.g. N‐deposition). Non‐clonal species may instead face environmental changes differently; some will go extinct, whereas others will survive, depending on the prevailing abiotic pressures. This seems to challenge previous views that predicted clonal species to be the winners and non‐clonal species the losers against local extinction.
Functional island biogeography can provide eco–evolutionary insights into which main drivers contribute to shaping the distribution of organisms' forms and functions on islands. It does so by ...examining trait patterns. As a result, traits are increasingly studied on islands, either along insularity gradients or by comparing patterns of island versus mainland biota. So far, functional island biogeography has investigated trends of trait values (i.e., average, functional diversity), whereas coordination between pairs of traits remains unexplored along insularity gradients. Yet, trait coordination analyses constitute the foundational tool to detect main functional spectra and strategies of organisms. In this perspective, we set out to offer a conceptual and analytical framework that should facilitate the inclusion of trait coordination (i.e., the co–variation of traits both at the intra– and interspecific level) in functional island biogeography. We illustrate, with a case study focused on persistence traits of edaphic island plant specialists, what type of insights can be gained by examining the response of trait coordination to variation in insularity. We asked two questions, namely whether, with increasing insularity, the strength of the relationship (R2) increases (Q1), and the direction of the relationship (slope) decreases (Q2). We positively answered our research questions, with lines of evidence suggesting a selective “forcing” towards tighter and more strongly coordinated strategies (Q1), and functional trade‐offs (Q2). We infer which ecological and biogeographic drivers could be behind the observed patterns, while acknowledging possible drawbacks. We conclude by identifying three main take–home messages and related future directions for integrating trait coordination in functional island biogeography to further advance the field.
Driscoll et al. (Journal of Biogeography, 2019, 46, 2850–2859) provide a critique of ‘Countryside Biogeography’, but also include ‘Conservation Biogeography’ and ‘Agriculture Biogeography’ in their ...criticisms. Their main thesis is that these new sub‐disciplines offer a ‘conceptual wrapper’ rather than distinctive frameworks and that the consequent redundancy of terms has the potential to sow confusion among biogeographers and slow progress. Here we argue that, far from sowing confusion Conservation Biogeography, for example, has provided important focal points for emerging scientific discourse, promoting new research, spawning undergraduate and graduate courses, and facilitating the formation of new scientific collaborations. The success or failure of a new sub‐discipline depends on its utility. If new framings sow confusion, introduce redundancy and provide no new insights they will not be widely adopted and cited. The development of new sub‐disciplines is a strong indicator of a vibrant, socially relevant and intellectually adventurous research area.
Recent work in island biogeography has shown that back-colonization (‘boomerang’ events) from islands to continents have occurred more frequently than previously understoodWe report possibly the ...earliest inference of this pattern, by John Ball and Joseph Dalton Hooker in a book published in 1878.
•The spatial variation of plankton in multi-tributary river was unveiled.•Water quality and hydro-morphological factors determined the variation of plankton.•Obvious variations in plankton assembly ...were observed from upstream to downstream.•The stability of plankton network decreased from upstream to downstream.
Revealing the spatial variation in phytoplankton and zooplankton communities, along with their responses to water flow, climate, and water quality from headwaters to downstream, is crucial for grasping their evolutionary dynamics and crafting ecological preservation strategies. Here, the spatial distribution, assembly processes, and stability changes of phytoplankton and zooplankton in the tributaries from headwaters to downstream reaches of the Danjiang River and the upper Hanjiang River (China) were analyzed using environmental DNA (eDNA) technology. Geographic factors accounted for over 60% of the variation in the distribution of phytoplankton and zooplankton, although environmental factors also played a significant role. From upstream to downstream, the proportion of phytoplankton Bacillariophyta decreased from 37.12% to 33.07% in March and from 27.68% to 25.36% in August. Euglenophyta decreased from 1.04% to 0.53% in March and 10.48% to 2.16% in August. The proportion of zooplankton Ciliophora increased from 67.17% to 85.04%, while Amoebozoa decreased by approximately 9.83% in August. Phytoplankton and zooplankton richness initially increased, then declined from upstream to downstream. The assembly of zooplankton and phytoplankton communities was mainly driven by deterministic processes, with values ranging from 0.2 to 0.5. Furthermore, the upstream community showed a stronger dominance of deterministic processes, while the mainstream community exhibited weaker determinism than the tributaries. In both March and August, zooplankton were more influenced by deterministic processes than phytoplankton. From upstream to downstream, the stability and complexity of phytoplankton and zooplankton networks decreased, significantly influenced by river width, flow velocity, agricultural land proportion, and nutrient concentration. Maintaining diverse phytoplankton was crucial for sustaining zooplankton diversity and ensuring network stability. Furthermore, the growth duration of phytoplankton and zooplankton was influenced by the spatial distribution of sampling points in the river, contributing to complex interactions with environmental factors. The complexity of these interactions necessitates careful consideration in future studies on spatial patterns in riverine plankton communities.
Habitat islands can be defined as distinct patches of habitat surrounded by less contrasting matrix types. In contrast to true island biogeography (traditionally the study of islands surrounded by ...water), there have been less efforts to synthesize the myriad habitat island biogeography studies that have been published, particularly syntheses that cover the full range of habitat island types. By building on previous work, I aim to provide a review of habitat island biogeography in order to provide a blueprint for future research on habitat islands, including both naturally and anthropogenically fragmented systems. The review is organized into three main parts. First, the differences between habitat and true islands are summarized. Second, the main theoretical frameworks currently used to analyze habitat island systems are reviewed. Third, the findings of habitat island studies focused on various biological patterns are synthesized. Drawing on this synthesis, I put forward two main points regarding improving our understanding of habitat island biogeography: first, increasing the integration of matrix properties (including matrix variation across space and time) into habitat island biogeographic models and, second, testing for, and understanding the implications of, the potential prevalence of mass effects and source-sink dynamics in habitat island systems.
Species of wolf spiders considered in the
Pardosa
atrata
group are surveyed, and comparative figures of all species included in the group are presented for the first time. A new species,
P.
armeniaca
...sp. nov.
, is described from the shore of Lake Sevan (Armenia) based on both sexes.
Pardosa
narymica
Savelyeva, 1972 from East Kazakhstan Oblast’ is synonymized with the trans-Palaearctic
P.
atrata
(Thorell, 1873). It was found that the record of
P.
atrata
(sub
P.
lapponica
) by Schenkel from British Columbia and reflected in the World Spider Catalog in fact refers to
P.
concinna
(Thorell, 1877), a member of the
P.
lapponica
group. The distribution of three species consideredin the
atrata
group are mapped. The discovery of
P.
armeniaca
sp. nov.
has led to a re-evaluation of the distribution range, previously thought to be continuous, now showing a disjunctive pattern.
Island biogeography Whittaker, Robert J.; Fernández-Palacios, José María; Matthews, Thomas J. ...
Science,
09/2017, Letnik:
357, Številka:
6354
Journal Article
Recenzirano
Odprti dostop
Islands provide classic model biological systems. We review how growing appreciation of geoenvironmental dynamics of marine islands has led to advances in island biogeographic theory accommodating ...both evolutionary and ecological phenomena. Recognition of distinct island geodynamics permits general models to be developed and modified to account for patterns of diversity, diversification, lineage development, and trait evolution within and across island archipelagos. Emergent patterns of diversity include predictable variation in island species-area relationships, progression rule colonization from older to younger land masses, and syndromes including loss of dispersability and secondary woodiness in herbaceous plant lineages. Further developments in Earth system science, molecular biology, and trait data for islands hold continued promise for unlocking many of the unresolved questions in evolutionary biology and biogeography.
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