scholarly journals Disentangling nutritional pathways linking leafcutter ants and their co-evolved fungal symbionts using stable isotopes

Ecology ◽  
2018 ◽  
Vol 99 (9) ◽  
pp. 1999-2009 ◽  
Author(s):  
Jonathan Z. Shik ◽  
Winnie Rytter ◽  
Xavier Arnan ◽  
Anders Michelsen
2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.


Author(s):  
J. BERRY, ◽  
C. COOK, ◽  
T.F. DOMINGUES, ◽  
J. EHLERINGER, ◽  
L. FLANAGAN, ◽  
...  

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.


IJOHMN ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 22-52
Author(s):  
Jalal Uddin Khan

Overlapping and interconnected, interdisciplinary and heterogeneous, amorphous and multi-layered, and deep and broad as it is, countless topics on ecoliterature make ecocriticism a comprehensive catchall term that proposes to look at a text--be it social, cultural, political, religious, or scientific--from naturalist perspectives and moves us from “the community of literature to the larger biospheric community which […] we belong to even as we are destroying it” (William Rueckert). As I was in the middle of writing and researching for this article, I was struck by a piece of nature writing by an eleven year old sixth grader born to his (South Asian and American) mixed parents, both affiliated with Johns Hopkins and already proud to belong to the extended family of a Nobel Laureate in Physics. The young boy, Rizwan Thorne-Lyman, wrote, as his science story project, an incredibly beautiful essay, “A Day in the Life of the Amazon Rainforest.” Reading about the rainforest was one of his interests, I was told. In describing the day-long activities of birds and animals among the tall trees and small plants, the 2 pp.-long narrative actually captures the eternally continuing natural cycle of the Amazon. The budding naturalist’s neat classification of the wild life into producers (leafy fruit and flowering plants and trees), consumers (caimans/crocodiles, leafcutter ants, capuchin monkey), predators (macaws, harpy eagles, jaguars, green anaconda), decomposers (worms, fungi and bacteria), parasites (phorid flies) and scavengers (millipedes) was found to be unforgettably impressive. Also the organization of the essay into the Amazon’s mutually benefitting and organically functioning flora and fauna during the day--sunrise, midday, and sunset--was unmistakably striking. I congratulated him as an aspiring environmentalist specializing in rain forest. I encouraged him that he should try to get his essay published in a popular magazine like Reader’s Digest (published did he get in no time indeed![i]) and that he should also read about (and visit) Borneo in Southeast Asia, home to other great biodiverse rainforests of the world. I called him “soft names” as a future Greenpeace and Environmental Protection leader and theorist, a soon-to-be close friend of Al Gore’s. The promising boy’s understanding, however short, of the Amazon ecology and ecosystem and the biological phenomena of its living organisms was really amazing. His essay reminded me of other famous nature writings, especially those by Fiona Macleod (see below), that are the pleasure of those interested in the ecocriticism of the literature of place--dooryards, backyards, outdoors, open fields, parks and farms, fields and pastures, and different kinds of other wildernesses.   [i] https://stonesoup.com/post/a-day-in-the-life-in-the-amazon-rainforest/


Author(s):  
В М. Андреянов ◽  
В. В. Русин ◽  
В. А. Удод ◽  
І. В. Хіміч ◽  
Л. М. Шомко

Sign in / Sign up

Export Citation Format

Share Document