Biodiversity of coral reef cryptobiota shuffles but does not decline under the combined stressors of ocean warming and acidification

Ocean-warming and acidification are predicted to reduce coral reef biodiversity, but the combined effects of these stressors on overall biodiversity are largely unmeasured. Here, we examined the individual and combined effects of elevated temperature (+2 °C) and reduced pH (−0.2 units) on the biodiversity of coral reef communities that developed on standardized sampling units over a 2-y mesocosm experiment. Biodiversity and species composition were measured using amplicon sequencing libraries targeting the cytochrome oxidase I (COI) barcoding gene. Ocean-warming significantly increased species richness relative to present-day control conditions, whereas acidification significantly reduced richness. Contrary to expectations, species richness in the combined future ocean treatment with both warming and acidification was not significantly different from the present-day control treatment. Rather than the predicted collapse of biodiversity under the dual stressors, we find significant changes in the relative abundance but not in the occurrence of species, resulting in a shuffling of coral reef community structure among the highly species-rich cryptobenthic community. The ultimate outcome of altered community structure for coral reef ecosystems will depend on species-specific ecological functions and community interactions. Given that most species on coral reefs are members of the understudied cryptobenthos, holistic research on reef communities is needed to accurately predict diversity–function relationships and ecosystem responses to future climate conditions.

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Experimental reef communities persist under future ocean acidification and warming

10.21203/rs.3.rs-640089/v1 ◽

2021 ◽

Author(s):

Christopher Jury ◽

Keisha Bahr ◽

Evan Barba ◽

Russell Brainard ◽

Annick Cros ◽

...

Keyword(s):

Experimental Study ◽

Species Richness ◽

Coral Reef ◽

Coral Reefs ◽

Ocean Acidification ◽

Community Composition ◽

Functional State ◽

Reef Communities ◽

Paris Climate Agreement

Abstract Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to acidification (-0.2 pH units), warming (+ 2°C), and combined future ocean (-0.2 pH, + 2°C) treatments. We show that under future ocean conditions, net calcification rates declined yet remained positive, corals showed reduced abundance yet were not extirpated, and community composition shifted while species richness was maintained. Our results suggest that under Paris Climate Agreement targets, coral reefs could persist in an altered functional state rather than collapse.

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Herbivore species richness and feeding complementarity affect community structure and function on a coral reef

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0801946105 ◽

2008 ◽

Vol 105 (42) ◽

pp. 16201-16206 ◽

Cited By ~ 268

Author(s):

D. E. Burkepile ◽

M. E. Hay

Keyword(s):

Species Richness ◽

Community Structure ◽

Coral Reef ◽

Structure And Function ◽

Herbivore Species ◽

And Function

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Faculty Opinions recommendation of Connectivity and the development of population genetic structure in Indo-West Pacific coral reef communities.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13364959.14735059 ◽

2011 ◽

Author(s):

Nicholas Graham

Keyword(s):

Coral Reef ◽

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

West Pacific ◽

Reef Communities ◽

Coral Reef Communities

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Winter Wheat Adaptation to Climate Change in Turkey

Agronomy ◽

10.3390/agronomy11040689 ◽

2021 ◽

Vol 11 (4) ◽

pp. 689

Author(s):

Yuksel Kaya

Keyword(s):

Climate Change ◽

Winter Wheat ◽

Grain Yield ◽

Spring Wheat ◽

Control Treatment ◽

Climate Change Scenarios ◽

Combined Effects ◽

Adaptation To Climate Change ◽

Wheat Genotypes ◽

Plant Characteristics

Climate change scenarios reveal that Turkey’s wheat production area is under the combined effects of heat and drought stresses. The adverse effects of climate change have just begun to be experienced in Turkey’s spring and the winter wheat zones. However, climate change is likely to affect the winter wheat zone more severely. Fortunately, there is a fast, repeatable, reliable and relatively affordable way to predict climate change effects on winter wheat (e.g., testing winter wheat in the spring wheat zone). For this purpose, 36 wheat genotypes in total, consisting of 14 spring and 22 winter types, were tested under the field conditions of the Southeastern Anatolia Region, a representative of the spring wheat zone of Turkey, during the two cropping seasons (2017–2018 and 2019–2020). Simultaneous heat (>30 °C) and drought (<40 mm) stresses occurring in May and June during both growing seasons caused drastic losses in winter wheat grain yield and its components. Declines in plant characteristics of winter wheat genotypes, compared to those of spring wheat genotypes using as a control treatment, were determined as follows: 46.3% in grain yield, 23.7% in harvest index, 30.5% in grains per spike and 19.4% in thousand kernel weight, whereas an increase of 282.2% in spike sterility occurred. On the other hand, no substantial changes were observed in plant height (10 cm longer than that of spring wheat) and on days to heading (25 days more than that of spring wheat) of winter wheat genotypes. In general, taller winter wheat genotypes tended to lodge. Meanwhile, it became impossible to avoid the combined effects of heat and drought stresses during anthesis and grain filling periods because the time to heading of winter wheat genotypes could not be shortened significantly. In conclusion, our research findings showed that many winter wheat genotypes would not successfully adapt to climate change. It was determined that specific plant characteristics such as vernalization requirement, photoperiod sensitivity, long phenological duration (lack of earliness per se) and vulnerability to diseases prevailing in the spring wheat zone, made winter wheat difficult to adapt to climate change. The most important strategic step that can be taken to overcome these challenges is that Turkey’s wheat breeding program objectives should be harmonized with the climate change scenarios.

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Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory

Plants ◽

10.3390/plants10081522 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1522

Author(s):

Hikaru Endo ◽

Toru Sugie ◽

Yukiko Yonemori ◽

Yuki Nishikido ◽

Hikari Moriyama ◽

...

Keyword(s):

Growth Rate ◽

High Temperature ◽

Nutrient Availability ◽

Vegetative Reproduction ◽

Ocean Warming ◽

Regeneration Ability ◽

Combined Effects ◽

Regeneration Rate ◽

Fish Herbivory ◽

C 30

Ocean warming and the associated changes in fish herbivory have caused polarward distributional shifts in the majority of canopy-forming macroalgae that are dominant in temperate Japan, but have little effect on the alga Sargassum fusiforme. The regeneration ability of new shoots from holdfasts in this species may be advantageous in highly grazed environments. However, little is known about the factors regulating this in Sargassum species. Moreover, holdfast tolerance to high-temperature and nutrient-poor conditions during summer has rarely been evaluated. In the present study, S. fusiforme holdfast responses to the combined effects of temperature and nutrient availability were compared to those of sexually reproduced propagules. The combined effects of holdfast fragmentation and irradiance on regeneration were also evaluated. Propagule growth rate values changed from positive to negative under the combination of elevated temperature (20 °C–30 °C) and reduced nutrient availability, whereas holdfasts exhibited a positive growth rate even at 32 °C in nutrient-poor conditions. The regeneration rate increased with holdfast fragmentation (1 mm segments), but was unaffected by decreased irradiance. These results suggest that S. fusiforme holdfasts have a higher tolerance to high-temperature and nutrient-poor conditions during summer than propagules, and regenerate new shoots even if 1-mm segments remain in shaded refuges for fish herbivory avoidance.

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Microbial Community Structure in Arctic Lake Sediments Reflect Variations in Holocene Climate Conditions

Frontiers in Microbiology ◽

10.3389/fmicb.2020.01520 ◽

2020 ◽

Vol 11 ◽

Author(s):

Tor Einar Møller ◽

Willem G.M. van der Bilt ◽

Desiree L. Roerdink ◽

Steffen L. Jørgensen

Keyword(s):

Community Structure ◽

Microbial Community ◽

Lake Sediments ◽

Microbial Community Structure ◽

Holocene Climate ◽

Climate Conditions ◽

Arctic Lake

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Glacier ice archives nearly 15,000-year-old microbes and phages

Microbiome ◽

10.1186/s40168-021-01106-w ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Zhi-Ping Zhong ◽

Funing Tian ◽

Simon Roux ◽

M. Consuelo Gazitúa ◽

Natalie E. Solonenko ◽

...

Keyword(s):

Climate Change ◽

Ice Core ◽

Ice Cores ◽

Single Species ◽

Amplicon Sequencing ◽

Future Climate Change ◽

Climate Conditions ◽

Glacier Ice ◽

Sampling Procedures ◽

Functional Genome

Abstract Background Glacier ice archives information, including microbiology, that helps reveal paleoclimate histories and predict future climate change. Though glacier-ice microbes are studied using culture or amplicon approaches, more challenging metagenomic approaches, which provide access to functional, genome-resolved information and viruses, are under-utilized, partly due to low biomass and potential contamination. Results We expand existing clean sampling procedures using controlled artificial ice-core experiments and adapted previously established low-biomass metagenomic approaches to study glacier-ice viruses. Controlled sampling experiments drastically reduced mock contaminants including bacteria, viruses, and free DNA to background levels. Amplicon sequencing from eight depths of two Tibetan Plateau ice cores revealed common glacier-ice lineages including Janthinobacterium, Polaromonas, Herminiimonas, Flavobacterium, Sphingomonas, and Methylobacterium as the dominant genera, while microbial communities were significantly different between two ice cores, associating with different climate conditions during deposition. Separately, ~355- and ~14,400-year-old ice were subject to viral enrichment and low-input quantitative sequencing, yielding genomic sequences for 33 vOTUs. These were virtually all unique to this study, representing 28 novel genera and not a single species shared with 225 environmentally diverse viromes. Further, 42.4% of the vOTUs were identifiable temperate, which is significantly higher than that in gut, soil, and marine viromes, and indicates that temperate phages are possibly favored in glacier-ice environments before being frozen. In silico host predictions linked 18 vOTUs to co-occurring abundant bacteria (Methylobacterium, Sphingomonas, and Janthinobacterium), indicating that these phages infected ice-abundant bacterial groups before being archived. Functional genome annotation revealed four virus-encoded auxiliary metabolic genes, particularly two motility genes suggest viruses potentially facilitate nutrient acquisition for their hosts. Finally, given their possible importance to methane cycling in ice, we focused on Methylobacterium viruses by contextualizing our ice-observed viruses against 123 viromes and prophages extracted from 131 Methylobacterium genomes, revealing that the archived viruses might originate from soil or plants. Conclusions Together, these efforts further microbial and viral sampling procedures for glacier ice and provide a first window into viral communities and functions in ancient glacier environments. Such methods and datasets can potentially enable researchers to contextualize new discoveries and begin to incorporate glacier-ice microbes and their viruses relative to past and present climate change in geographically diverse regions globally.

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