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Breitkreutz A, Coleman LJM, Martone PT. Less Than the Sum of Its Parts: Blade Clustering Reduces Drag in the Bull Kelp, Nereocystis luetkeana (Phaeophyceae). JOURNAL OF PHYCOLOGY 2022; 58:603-611. [PMID: 35582822 DOI: 10.1111/jpy.13258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
Nereocystis luetkeana is a large, canopy-forming kelp that is commonly found in nearshore waters between Alaska and California. Despite regularly reaching lengths in excess of 30 m, this alga demonstrates a remarkable ability to endure hydrodynamically stressful environments without being dislodged by waves or currents. While morphological aspects of this kelp, including its long flexible stipe, have been shown to reduce drag, blade clustering has never been directly tested. In this study, we examined how the distinctive multi-bladed morphology of Nereocystis thalli limits drag in flow. We measured drag on whole kelps in a large recirculating flume and quantified how drag was affected by serial removal of blades. We then compared measured drag with predictions of "additive drag", which we defined as the sum of the drag that each blade experiences in isolation. We found that, on average, intact thalli experience only 37% of the predicted additive drag when subjected to a flow rate of 0.40-0.50 m · s-1 . Our results indicate that the subdivision of the photosynthetic area into multiple blades has a drag-reducing effect on Nereocystis thalli. We found drag increases less than proportionally with the cumulative area, meaning the contribution of individual blades to overall drag decreases with increasing blade number. That is, as thalli develop, each additional blade incurs a reduced hydrodynamic cost, perhaps lending insight into how thalli can grow so large.
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Affiliation(s)
- Alana Breitkreutz
- Department of Botany & Biodiversity Research Centre, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Liam J M Coleman
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S6, Canada
| | - Patrick T Martone
- Department of Botany & Biodiversity Research Centre, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, V6T 1Z4, Canada
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2
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Dai X, Yu X, Zheng J, Yang X, Pan J, Zhang X, Min J. A kelp‐inspired polyester fabric surface of
UV
grafted hydrogel for drag reduction. J Appl Polym Sci 2022. [DOI: 10.1002/app.51634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xianghui Dai
- College of Chemistry, Chemical Engineering and Biotechnology Donghua University Shanghai China
| | - Xia Yu
- College of Chemistry, Chemical Engineering and Biotechnology Donghua University Shanghai China
| | - Jian Zheng
- College of Chemistry, Chemical Engineering and Biotechnology Donghua University Shanghai China
| | - Xiaoxu Yang
- College of Chemistry, Chemical Engineering and Biotechnology Donghua University Shanghai China
| | | | | | - Jie Min
- College of Chemistry, Chemical Engineering and Biotechnology Donghua University Shanghai China
- Key Laboratory of Textile Science & Technology Ministry of Education Shanghai China
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3
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Morphological complexity affects the diversity of marine microbiomes. ISME JOURNAL 2020; 15:1372-1386. [PMID: 33349654 DOI: 10.1038/s41396-020-00856-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 11/06/2020] [Accepted: 11/24/2020] [Indexed: 02/06/2023]
Abstract
Large eukaryotes support diverse communities of microbes on their surface-epibiota-that profoundly influence their biology. Alternate factors known to structure complex patterns of microbial diversity-host evolutionary history and ecology, environmental conditions and stochasticity-do not act independently and it is challenging to disentangle their relative effects. Here, we surveyed the epibiota from 38 sympatric seaweed species that span diverse clades and have convergent morphology, which strongly influences seaweed ecology. Host identity explains most of the variation in epibiont communities and deeper host phylogenetic relationships (e.g., genus level) explain a small but significant portion of epibiont community variation. Strikingly, epibiota community composition is significantly influenced by host morphology and epibiota richness increases with morphological complexity of the seaweed host. This effect is robust after controlling for phylogenetic non-independence and is strongest for crustose seaweeds. We experimentally validated the effect of host morphology by quantifying bacterial community assembly on latex sheets cut to resemble three seaweed morphologies. The patterns match those observed in our field survey. Thus, biodiversity increases with habitat complexity in host-associated microbial communities, mirroring patterns observed in animal communities. We suggest that host morphology and structural complexity are underexplored mechanisms structuring microbial communities.
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Coleman LJM, Martone PT. Morphological plasticity in the kelp Nereocystis luetkeana (Phaeophyceae) is sensitive to the magnitude, direction, and location of mechanical loading. JOURNAL OF PHYCOLOGY 2020; 56:1414-1427. [PMID: 32602559 DOI: 10.1111/jpy.13043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Nereocystis luetkeana is a canopy-forming kelp that exhibits morphological plasticity across hydrodynamic gradients, producing broad, undulate blades in slow flow and narrow, flattened blades in fast flow, enabling thalli to reduce drag while optimizing photosynthesis. While the functional significance of this phenomenon has been well studied, the developmental and physiological mechanisms that facilitate the plasticity remain poorly understood. In this study, we conducted three experiments to characterize how the (1) magnitude, (2) direction, and (3) location of plasticity-inducing mechanical stimuli affect the morphology of Nereocystis blades. We found that applying a gradient of tensile force caused blades to grow progressively longer, narrower, less ruffled, and heavier in a linear fashion, suggesting that Nereocystis is equally well adapted for all conditions within its hydrodynamic niche. We also found that applying tension transversely across blades caused the growth response to rotate 90°, indicating that there is no substantial separation between the sites of stimulus perception and response and suggesting that a long-distance signaling mechanism, such as a hormone, is unlikely to mediate this phenomenon. Meristoderm cells showed morphological changes that paralleled those of their respective blades in this experiment, implying that tissue-level morphology is influenced by cell growth. Finally, we found that plasticity was only induced when tension was applied directly to the growing tissue, reinforcing that long-distance signaling is probably not involved and possibly indicating that the mechanism on display generally requires an intercalary meristem to facilitate mechanoperception.
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Affiliation(s)
- Liam J M Coleman
- Department of Botany & Biodiversity Research Centre, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Patrick T Martone
- Department of Botany & Biodiversity Research Centre, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, V6T 1Z4, Canada
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5
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Best RJ. The evolution of community assembly in marine foundation species. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rebecca J. Best
- School of Earth & Sustainability Northern Arizona University Flagstaff AZ USA
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6
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Starko S, Demes KW, Neufeld CJ, Martone PT. Convergent evolution of niche structure in Northeast Pacific kelp forests. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13621] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Samuel Starko
- Department of Botany & Biodiversity Research Centre University of British Columbia Vancouver BC Canada
- Department of Biology University of Victoria Victoria BC Canada
- Bamfield Marine Sciences Centre Bamfield BC Canada
| | - Kyle W. Demes
- Institutional Strategic Awards Simon Fraser University Burnaby BC Canada
| | | | - Patrick T. Martone
- Department of Botany & Biodiversity Research Centre University of British Columbia Vancouver BC Canada
- Bamfield Marine Sciences Centre Bamfield BC Canada
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7
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Gosselin FP. Mechanics of a plant in fluid flow. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3533-3548. [PMID: 31198946 DOI: 10.1093/jxb/erz288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
Plants live in constantly moving fluid, whether air or water. In response to the loads associated with fluid motion, plants bend and twist, often with great amplitude. These large deformations are not found in traditional engineering application and thus necessitate new specialized scientific developments. Studying fluid-structure interaction (FSI) in botany, forestry, and agricultural science is crucial to the optimization of biomass production for food, energy, and construction materials. FSIs are also central in the study of the ecological adaptation of plants to their environment. This review paper surveys the mechanics of FSI on individual plants. I present a short refresher on fluid mechanics then dive into the statics and dynamics of plant-fluid interactions. For every phenomenon considered, I examine the appropriate dimensionless numbers to characterize the problem, discuss the implications of these phenomena on biological processes, and propose future research avenues. I cover the concept of reconfiguration while considering poroelasticity, torsion, chirality, buoyancy, and skin friction. I also assess the dynamical phenomena of wave action, flutter, and vortex-induced vibrations.
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Affiliation(s)
- Frédérick P Gosselin
- Laboratory for Multiscale Mechanics, Department of Mechanical Engineering, Polytechnique Montréal, Montréal, QC, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
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Starko S, Soto Gomez M, Darby H, Demes KW, Kawai H, Yotsukura N, Lindstrom SC, Keeling PJ, Graham SW, Martone PT. A comprehensive kelp phylogeny sheds light on the evolution of an ecosystem. Mol Phylogenet Evol 2019; 136:138-150. [PMID: 30980936 DOI: 10.1016/j.ympev.2019.04.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/24/2022]
Abstract
Reconstructing phylogenetic topologies and divergence times is essential for inferring the timing of radiations, the appearance of adaptations, and the historical biogeography of key lineages. In temperate marine ecosystems, kelps (Laminariales) drive productivity and form essential habitat but an incomplete understanding of their phylogeny has limited our ability to infer their evolutionary origins and the spatial and temporal patterns of their diversification. Here, we reconstruct the diversification of habitat-forming kelps using a global genus-level phylogeny inferred primarily from organellar genome datasets, and investigate the timing of kelp radiation. We resolve several important phylogenetic features, including relationships among the morphologically simple kelp families and the broader radiation of complex kelps, demonstrating that the initial radiation of the latter resulted from an increase in speciation rate around the Eocene-Oligocene boundary. This burst in speciation rate is consistent with a possible role of recent climatic cooling in triggering the kelp radiation and pre-dates the origin of benthic-foraging carnivores. Historical biogeographical reconstructions point to a northeast Pacific origin of complex kelps, with subsequent colonization of new habitats likely playing an important role in driving their ecological diversification. We infer that complex morphologies associated with modern kelp forests (e.g. branching, pneumatocysts) evolved several times over the past 15-20 MY, highlighting the importance of morphological convergence in establishing modern upright kelp forests. Our phylogenomic findings provide new insights into the geographical and ecological proliferation of kelps and provide a timeline along which feedbacks between kelps and their food-webs could have shaped the structure of temperate ecosystems.
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Affiliation(s)
- Samuel Starko
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Bamfield Marine Sciences Centre, 100 Pachena Rd., Bamfield V0R 1B0, Canada; Hakai Institute, Heriot Bay, Quadra Island, Canada.
| | - Marybel Soto Gomez
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Hayley Darby
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Kyle W Demes
- Department of Zoology, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Hiroshi Kawai
- Department of Biology, Kobe University, Rokkodaicho 657-8501, Japan
| | - Norishige Yotsukura
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo 060-0809, Japan
| | - Sandra C Lindstrom
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Patrick J Keeling
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Department of Zoology, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Sean W Graham
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Patrick T Martone
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Bamfield Marine Sciences Centre, 100 Pachena Rd., Bamfield V0R 1B0, Canada; Hakai Institute, Heriot Bay, Quadra Island, Canada
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9
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Demes KW, Pruitt JN. Individuality in seaweeds and why we need to care. JOURNAL OF PHYCOLOGY 2019; 55:247-256. [PMID: 30802959 DOI: 10.1111/jpy.12845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Documenting the causes and consequences of intraspecific variation forms the foundation of much of evolutionary ecology. In this Perspectives piece, we review the importance of individual variation in ecology and evolution, argue that contemporary phycology often overlooks this foundational biological unit, and highlight how this lack of attention has potentially constrained our understanding of seaweeds. We then provide some suggestions of promising but underrepresented approaches, for instance: conducting more studies and analyses at the level of the individual; designing studies to evaluate heritability and genetic regulation of traits; and measuring associations between individual variation in functional traits and ecological outcomes. We close by highlighting areas of phycological research (e.g., population biology, ecology, aquaculture, climate change management) that could benefit immediately from including a focus on individual variation. Algae, for their part, provide us with a powerful and diverse set of ecological and evolutionary traits to explore these topics. There is much to be discovered.
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Affiliation(s)
- Kyle W Demes
- Department of Institutional Strategic Awards, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada, V5A 1S6
- Department of Zoology, The University of British Columbia, 2329 West Mall, Vancouver, British Columbia, Canada, V6T 1Z4
| | - Jonathan N Pruitt
- Department of Psychology, Neurobiology and Behaviour, McMaster University, Hamilton, Ontario, Canada, L8S 4K1
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93117, USA
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Liggan LM, Martone PT. Under pressure: biomechanical limitations of developing pneumatocysts in the bull kelp (Nereocystis luetkeana, Phaeophyceae). JOURNAL OF PHYCOLOGY 2018; 54:608-615. [PMID: 30098020 DOI: 10.1111/jpy.12776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
Maintaining buoyancy with gas-filled floats (pneumatocysts) is essential for some subtidal kelps to achieve an upright stature and compete for light . However, as these kelps grow up through the water column, pneumatocysts are exposed to substantial changes in hydrostatic pressure, which could cause complications as internal gases may expand or contract, potentially causing them to rupture, flood, and lose buoyancy. In this study, we investigate how pneumatocysts of Nereocystis luetkeana resist biomechanical stress and maintain buoyancy as they develop across a hydrostatic gradient. We measured internal pressure, material properties, and pneumatocyst geometry across a range of thallus sizes and collection depths to identify strategies used to resist pressure-induced mechanical failure. Contrary to expectations, all pneumatocysts had internal pressures less than atmospheric pressure, ensuring that thalli are always exposed to a positive pressure gradient and compressional loads, indicating that they are more likely to buckle than rupture at all depths. Small pneumatocysts collected from depths between 1 and 9 m (inner radius = 0.4-1.0 cm) were demonstrated to have elevated wall stresses under high compressive loads and are at greatest risk of buckling. Although small kelps do not adjust pneumatocyst material properties or geometry to reduce wall stress as they grow, they are ~3.4 times stronger than they need to be to resist hydrostatic buckling. When tested, pneumatocysts buckled around 35 m depth, which agrees with previous measures of lower limits due to light attenuation, suggesting that hydrostatic pressure may also define the lower limit of Nereocystis in the field.
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Affiliation(s)
- Lauran M Liggan
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
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11
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Starko S, Martone PT. An empirical test of 'universal' biomass scaling relationships in kelps: evidence of convergence with seed plants. THE NEW PHYTOLOGIST 2016; 212:719-729. [PMID: 27479188 DOI: 10.1111/nph.14120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/16/2016] [Indexed: 06/06/2023]
Abstract
Biomass allocation patterns have received substantial consideration, leading to the recognition of several 'universal' interspecific trends. Despite efforts to understand biomass partitioning among embryophytes, few studies have examined macroalgae that evolved independently, yet function ecologically in much the same ways as plants. Kelps allocate photosynthate among three organs (the blade(s), stipe(s) and holdfast) that are superficially convergent with organs of land plants, providing a unique opportunity to test the limits of 'universal' trends. In this study, we used an allometric approach to quantify interspecific biomass partitioning patterns in kelps and assess whether embryophyte-based predictions of biomass scaling can be applied to marine macrophytes that lack root-to-leaf hydraulic transport. Photosynthetic area and dry mass were found to scale to approximately the ¾ power and kelp biomass allocation patterns were shown to match closely to empirical measures of allometric scaling among woody plants. Larger kelp species were found to have increased relative stipe and holdfast mass than smaller species, highlighting important consequences of size for marine macroalgae. Our study provides insights into the evolution of size in the largest marine macrophytes and corroborates previous work suggesting that the morphology of divergent lineages of photoautotrophs may reflect similar selective pressures.
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Affiliation(s)
- Samuel Starko
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada.
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada.
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada.
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada
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