Potential Nitrogen Fixation During Primary Succession in Hawai`i Volcanoes National Park

Biotropica ◽  
1994 ◽  
Vol 26 (3) ◽  
pp. 234 ◽  
Author(s):  
Peter M. Vitousek
1993 ◽  
Vol 23 (3) ◽  
pp. 197-215 ◽  
Author(s):  
Peter M. Vitousek ◽  
Lawrence R. Walker ◽  
Louis D. Whiteaker ◽  
Pamela A. Matson

1993 ◽  
Vol 71 (8) ◽  
pp. 1093-1096 ◽  
Author(s):  
D. J. Blundon ◽  
D. A. MacIsaac ◽  
M. R. T. Dale

A study of nucleation during primary succession was carried out on age sequences of communities at two sites in the Canadian Rocky Mountains: one at the Mount Robson moraines, British Columbia, the other at Southeast Lyell Glacier, Alberta. The study concentrated on the associations of species with the nitrogen-fixing plants Hedysarum boreale var. mackenzii at Mount Robson moraines and Dryas drummondii at Southeast Lyell Glacier because those plants might serve as nuclei for colonization by other species, thus facilitating succession. The data show that recruitment of later successional species is greater in patches of the two pioneer species, but the fact that recruitment takes place away from the plants also suggests that although there is nucleation, it is not necessary for succession at these sites. Key words: colonization, nitrogen fixation, nucleation, succession.


2021 ◽  
Vol 160 ◽  
pp. 103850
Author(s):  
Laura Pulido-Suárez ◽  
Francisco Díaz-Peña ◽  
Jesús Notario-del Pino ◽  
Ayose Medina-Cabrera ◽  
Milagros León-Barrios

2006 ◽  
Vol 22 (5) ◽  
pp. 609-612 ◽  
Author(s):  
Tetsushi Inoue ◽  
Yoko Takematsu ◽  
Akinori Yamada ◽  
Yuichi Hongoh ◽  
Toru Johjima ◽  
...  

Termites are dominant invertebrates in tropical soils (Wood & Sands 1978) and are important mediators of decomposition in terrestrial ecosystems (Abe & Matsumoto 1979, Lawton et al. 1996, Lee & Wood 1971, Matsumoto & Abe 1979, Wood & Sands 1978, Yamada et al. 2005). Furthermore, these processes, such as carbon mineralization and nitrogen fixation, are dependent on the species assemblage structure of the termite community (Lawton et al. 1996, Yamada et al. 2005, 2006). Feeding habits of termites reflect their metabolic processes. The three major isopteran groups – wood-feeders, fungus-growers (fungus-growing wood/litter feeders), soil-feeders – appear to play very different roles in the decomposition process (Tayasu et al. 1997, Wood 1976, Wood & Sands 1978, Yamada et al. 2005). Consequently, the relative abundance of each feeding group provides useful information on the function of the termite assemblage in an ecosystem.


2020 ◽  
Author(s):  
Annastacia C. Bennett ◽  
Senthil K. Murugapiran ◽  
Eric D. Kees ◽  
Trinity L. Hamilton

ABSTRACTAlkaline hot springs in Yellowstone National Park (YNP) provide a framework to study the relationship between photoautotrophs and temperature. Previous work has focused on cyanobacteria (oxygenic phototrophs), but anoxygenic phototrophs are critical parts of the evolutionary history of life on Earth and and are abundant across temperature gradients in alkaline hot springs. However, many questions remain regarding the ecophysiology of anoxygenic photosynthesis due to the taxonomic and metabolic diversity of these taxa. Here, we examined the distribution of genes involved in phototrophy and carbon and nitrogen fixation in eight alkaline (pH 7.3-9.4) hot spring sites approaching the upper temperature limit of photosynthesis (~72°C) in YNP using metagenome sequencing. Genes associated with cyanobacteria are abundant throughout our data and more diverse at temperatures > 63°C, genes for autotrophic Chloroflexi are more abundant in sites > 63°C and genes associated with phototrophic Chloroflexi are abundant throughout. Additionally, we recovered deep branching nitrogen fixation genes from our metagenomes, which could inform the evolutionary history of nitrogen fixation. Lastly, we recovered 25 metagenome assembled genomes of Chloroflexi. We found distinct differences in carbon fixation genes in Roseiflexus and Chloroflexus bins, in addition to several novel Chloroflexi bins. Our results highlight the physiological diversity and evolutionary history of the understudied, anoxygenic autotrophic Chloroflex. Furthermore, we provide evidence that genes involved in nitrogen fixation in Chloroflexi is more widespread than previously assumed.IMPORTANCEPhotosynthetic bacteria in hot springs are of great importance to both microbial evolution and ecology because they are responsible for the rise of oxygen and are critical to nutrient cycling. While a large body of work has focused on the oxygenic photosynthesis in cyanobacteria, many questions remain regarding the metabolic potential of anoxygenic phototrophs but are further compounded by their metabolic and taxonomic diversity. Here, we have recovered several novel metagenome bins and quantified the distribution of key genes involved in carbon and nitrogen metabolism in both oxygenic and anoxygenic phototrophs. Together, our results add to the body of work focusing on photosynthetic bacteria in hot springs in Yellowstone National Park.


Author(s):  
M. R. Edwards ◽  
J. D. Mainwaring

Although the general ultrastructure of Cyanidium caldarium, an acidophilic, thermophilic alga of questionable taxonomic rank, has been extensively studied (see review of literature in reference 1), some peculiar ultrastructural features of the chloroplast of this alga have not been noted by other investigators.Cells were collected and prepared for thin sections at the Yellowstone National Park and were also grown in laboratory cultures (45-52°C; pH 2-5). Fixation (glutaraldehyde-osmium), dehydration (ethanol), and embedding (Epon 812) were accomplished by standard methods. Replicas of frozenfracture d- etched cells were obtained in a Balzers apparatus. In addition, cells were examined after disruption in a French Press.


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