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Species traits and climate velocity explain geographic range shifts in an ocean‐warming hotspot 下载免费PDF全文
Jennifer M. Sunday Gretta T. Pecl Stewart Frusher Alistair J. Hobday Nicole Hill Neil J. Holbrook Graham J. Edgar Rick Stuart‐Smith Neville Barrett Thomas Wernberg Reg A. Watson Dan A. Smale Elizabeth A. Fulton Dirk Slawinski Ming Feng Ben T. Radford Peter A. Thompson Amanda E. Bates 《Ecology letters》2015,18(9):944-953
Species' ranges are shifting globally in response to climate warming, with substantial variability among taxa, even within regions. Relationships between range dynamics and intrinsic species traits may be particularly apparent in the ocean, where temperature more directly shapes species' distributions. Here, we test for a role of species traits and climate velocity in driving range extensions in the ocean‐warming hotspot of southeast Australia. Climate velocity explained some variation in range shifts, however, including species traits more than doubled the variation explained. Swimming ability, omnivory and latitudinal range size all had positive relationships with range extension rate, supporting hypotheses that increased dispersal capacity and ecological generalism promote extensions. We find independent support for the hypothesis that species with narrow latitudinal ranges are limited by factors other than climate. Our findings suggest that small‐ranging species are in double jeopardy, with limited ability to escape warming and greater intrinsic vulnerability to stochastic disturbances. 相似文献
224.
Fei‐Xue Fu Mark E. Warner Yaohong Zhang Yuanyuan Feng David A. Hutchins 《Journal of phycology》2007,43(3):485-496
Little is known about the combined impacts of future CO2 and temperature increases on the growth and physiology of marine picocyanobacteria. We incubated Synechococcus and Prochlorococcus under present‐day (380 ppm) or predicted year‐2100 CO2 levels (750 ppm), and under normal versus elevated temperatures (+4°C) in semicontinuous cultures. Increased temperature stimulated the cell division rates of Synechococcus but not Prochlorococcus. Doubled CO2 combined with elevated temperature increased maximum chl a–normalized photosynthetic rates of Synechococcus four times relative to controls. Temperature also altered other photosynthetic parameters (α, Φmax, Ek, and ) in Synechococcus, but these changes were not observed for Prochlorococcus. Both increased CO2 and temperature raised the phycobilin and chl a content of Synechococcus, while only elevated temperature increased divinyl chl a in Prochlorococcus. Cellular carbon (C) and nitrogen (N) quotas, but not phosphorus (P) quotas, increased with elevated CO2 in Synechococcus, leading to ~20% higher C:P and N:P ratios. In contrast, Prochlorococcus elemental composition remained unaffected by CO2, but cell volume and elemental quotas doubled with increasing temperature while maintaining constant stoichiometry. Synechococcus showed a much greater response to CO2 and temperature increases for most parameters measured, compared with Prochlorococcus. Our results suggest that global change could influence the dominance of Synechococcus and Prochlorococcus ecotypes, with likely effects on oligotrophic food‐web structure. However, individual picocyanobacteria strains may respond quite differently to future CO2 and temperature increases, and caution is needed when generalizing their responses to global change in the ocean. 相似文献
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Molecular and morphological diversity of Trebouxia microalgae in sphaerothallioid Circinaria spp. lichens1 下载免费PDF全文
Arántzazu Molins Francisco J. García‐Breijo José Reig‐Armiñana Eva Barreno 《Journal of phycology》2018,54(4):494-504
Three vagrant (Circinaria hispida, Circinaria gyrosa, and Circinaria sp. ‘paramerae’) and one crustose (semi‐vagrant, Circinaria sp. ‘oromediterranea’) lichens growing in very continental areas in the Iberian Peninsula were selected to study the phycobiont diversity. Mycobiont identification was checked using nrITS DNA barcoding: Circinaria sp. ‘oromediterranea’ and Circinaria sp. ‘paramerae’ formed a new clade. Phycobiont diversity was analyzed in 50 thalli of Circinaria spp. using nrITS DNA and LSU rDNA, with microalgae coexistence being found in all the species analyzed by Sanger sequencing. The survey of phycobiont diversity showed up to four different Trebouxia spp. as the primary phycobiont in 20 thalli of C. hispida, in comparison with the remaining Circinaria spp., where only one Trebouxia was the primary microalga. In lichen species showing coexistence, some complementary approaches are needed (454 pyrosequencing and/or ultrastructural analyses). Five specimens were selected for high‐throughput screening (HTS) analyses: 22 Trebouxia OTUs were detected, 10 of them not previously known. TEM analyses showed three different cell morphotypes (Trebouxia sp. OTU A12, OTU S51, and T. cretacea) whose ultrastructure is described here in detail for the first time. HTS revealed a different microalgae pool in each species studied, and we cannot assume a specific pattern between these pools and the ecological and/or morphological characteristics. The mechanisms involved in the selection of the primary phycobiont and the other microalgae by the mycobiont are unknown, and require complex experimental designs. The systematics of the genus Circinaria is not yet well resolved, and more analyses are needed to establish a precise delimitation of the species. 相似文献
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Length‐weight relationships for five Clupeiformes species from the Persian Gulf and Oman Sea 下载免费PDF全文
H. Mousavi‐Sabet H. Homayouni M. Marjani A. Heidari 《Zeitschrift fur angewandte Ichthyologie》2016,32(1):169-170
Length‐weight relationships (LWRs) were determined for five Clupeiformes species representing three families collected from the Persian Gulf and Oman Sea. These are the first references on length‐weight relationships for two of these species (Ilisha megaloptera and Sardinella sindensis). A new maximum length record was obtained for one species (Ilisha melastoma). 相似文献
229.
Carina Proença Marisa Freitas Daniela Ribeiro Eduardo F. T. Oliveira Joana L. C. Sousa Sara M. Tomé 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):1216-1228
α-Glucosidase inhibitors are described as the most effective in reducing post-prandial hyperglycaemia (PPHG) from all available anti-diabetic drugs used in the management of type 2 diabetes mellitus. As flavonoids are promising modulators of this enzyme’s activity, a panel of 44 flavonoids, organised in five groups, was screened for their inhibitory activity of α-glucosidase, based on in vitro structure–activity relationship studies. Inhibitory kinetic analysis and molecular docking calculations were also applied for selected compounds. A flavonoid with two catechol groups in A- and B-rings, together with a 3-OH group at C-ring, was the most active, presenting an IC50 much lower than the one found for the most widely prescribed α-glucosidase inhibitor, acarbose. The present work suggests that several of the studied flavonoids have the potential to be used as alternatives for the regulation of PPHG. 相似文献
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