The effect of the taxon and geographic range size of host eucalypt species on the species richness of gall-forming insects

1996 ◽  
Vol 21 (3) ◽  
pp. 332-335 ◽  
Author(s):  
K. ROSALIND BLANCHE ◽  
MARK WESTOBY
2021 ◽  
Author(s):  
Ingmar Staude ◽  
Henrique Pereira ◽  
Gergana N. Daskalova ◽  
Markus Bernhardt-Römermann ◽  
Martin Diekmann ◽  
...  

The direction and magnitude of long-term changes in local plant species richness are highly variable among studies, while species turnover is ubiquitous. However, it is unknown whether the nature of species turnover is idiosyncratic or whether certain types of species are consistently gained or lost across different habitats. To address this question, we analyzed the trajectories of 1,827 vascular plant species over time intervals of up to 78 years at 141 sites in three habitats in Europe – mountain summits, forests, and lowland grasslands. Consistent across all habitats, we found that plant species with small geographic ranges tended to be replaced by species with large ranges, despite habitat-specific trends in species richness. Our results point to a predictable component of species turnover, likely explained by aspects of species’ niches correlated with geographic range size. Species with larger ranges tend to be associated with nutrient-rich sites and we found community composition shifts towards more nutrient-demanding species in all three habitats. Global changes involving increased resource availability are thus likely to favor large-ranged, nutrient-demanding species, which are typically strong competitors. Declines of small-ranged species could reflect not only abiotic drivers of global change, but also biotic pressure from increased competition. Our study highlights the need to consider the traits of species such as the geographic range size when predicting how ecological communities will respond to global change.


Paleobiology ◽  
2021 ◽  
pp. 1-15
Author(s):  
Dana S. Friend ◽  
Brendan M. Anderson ◽  
Warren D. Allmon

Abstract Rates of speciation and extinction are often linked to many ecological factors, traits (emergent and nonemergent) such as environmental tolerance, body size, feeding type, and geographic range. Marine gastropods in particular have been used to examine the role of larval dispersal in speciation. However, relatively few studies have been conducted placing larval modes in species-level phylogenetic context. Those that have, have not incorporated fossil data, while landmark macroevolutionary studies on fossil clades have not considered both phylogenetic context and net speciation (speciation–extinction) rates. This study utilizes Eocene volutid Volutospina species from the U.S. Gulf Coastal Plain and the Hampshire Basin, U.K., to explore the relationships among larval mode, geographic range, and duration. Based on the phylogeny of these Volutospina, we calculated speciation and extinction rates in order to compare the macroevolutionary effects of larval mode. Species with planktotrophic larvae had a median duration of 9.7 Myr, which compared significantly to 4.7 Myr for those with non-planktotrophic larvae. Larval mode did not significantly factor into geographic-range size, but U.S. and U.K. species do differ, indicating a locality-specific component to maximum geographic-range size. Non-planktotrophs (NPTs)were absent among the Volutospina species during the Paleocene–early Eocene. The relative proportions of NPTs increased in the early middle Eocene, and the late Eocene was characterized by disappearance of planktotrophs (PTs). The pattern of observed lineage diversity shows an increasing preponderance of NPTs; however, this is clearly driven by a dramatic extinction of PTs, rather than higher NPT speciation rates during the late Eocene. This study adds nuance to paleontology's understanding of the macroevolutionary consequences of larval mode.


Paleobiology ◽  
2020 ◽  
pp. 1-14
Author(s):  
Michelle M. Casey ◽  
Erin E. Saupe ◽  
Bruce S. Lieberman

Abstract Geographic range size and abundance are important determinants of extinction risk in fossil and extant taxa. However, the relationship between these variables and extinction risk has not been tested extensively during evolutionarily “quiescent” times of low extinction and speciation in the fossil record. Here we examine the influence of geographic range size and abundance on extinction risk during the late Paleozoic (Mississippian–Permian), a time of “sluggish” evolution when global rates of origination and extinction were roughly half those of other Paleozoic intervals. Analyses used spatiotemporal occurrences for 164 brachiopod species from the North American midcontinent. We found abundance to be a better predictor of extinction risk than measures of geographic range size. Moreover, species exhibited reductions in abundance before their extinction but did not display contractions in geographic range size. The weak relationship between geographic range size and extinction in this time and place may reflect the relative preponderance of larger-ranged taxa combined with the physiographic conditions of the region that allowed for easy habitat tracking that dampened both extinction and speciation. These conditions led to a prolonged period (19–25 Myr) during which standard macroevolutionary rules did not apply.


Author(s):  
Katherine E Dale ◽  
Arturo Ramírez-Valdez ◽  
John E McCosker ◽  
Milton S Love

Under the influence of climate stressors, species distributions of fishes in the eastern Pacific are shifting, with many species moving poleward. Moray eels (family Muraenidae) are ecologically important predators inhabiting coastal reefs. Due to their cryptic nature and lack of commercial importance, the species distributions of muraenids in the tropical and subtropical eastern Pacific are poorly understood. Here, we document the geographic range size of 33 muraenid species in the eastern Pacific and also report a shift in the established population range of Muraena argus based on recent trapping efforts. We found that 17 species demonstrated shifts in geographic range size, including sampled-range expansions and new occurrences at offshore islands. Eleven species were observed in new biogeographic provinces, primarily in the northward direction to the San Diegan province. Trapping data and local knowledge gathered from fishing cooperatives suggest that M. argus has established populations at least 300 km further north than previously reported. Both the yearly number of reported observations and geographic extent of sampling have increased over time, but the number of recorded extensions has not. These results highlight the importance of compiling data from diverse sources (including museum records, local ecological knowledge, and the non-English scientific literature) as well as the continued value of biodiversity surveys in the eastern Pacific.


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