scholarly journals Colony-Level 3D Photogrammetry Reveals That Total Linear Extension and Initial Growth Do Not Scale With Complex Morphological Growth in the Branching Coral, Acropora cervicornis

2021 ◽  
Vol 8 ◽  
Author(s):  
Wyatt C. Million ◽  
Sibelle O’Donnell ◽  
Erich Bartels ◽  
Carly D. Kenkel

The ability to quantify changes in the structural complexity of reefs and individual coral colonies that build them is vital to understanding, managing, and restoring the function of these ecosystems. However, traditional methods for quantifying coral growth in situ fail to accurately quantify the diversity of morphologies observed both among and within species that contribute to topographical complexity. Three-dimensional (3D) photogrammetry has emerged as a powerful tool for the quantification of reefscape complexity but has yet to be broadly adopted for quantifying the growth and morphology of individual coral colonies. Here we debut a high-throughput method for colony-level 3D photogrammetry and apply this technique to explore the relationship between linear extension and other growth metrics in Acropora cervicornis. We fate-tracked 156 individual coral transplants to test whether initial growth can be used to predict subsequent patterns of growth. We generated photographic series of fragments in a restoration nursery immediately before transplanting to natural reef sites and re-photographed coral at 6 months and 1 year post-transplantation. Photosets were used to build 3D models with Agisoft Metashape, which was automated to run on a high-performance computing system using a custom script to serially process models without the need for additional user input. Coral models were phenotyped in MeshLab to obtain measures of total linear extension (TLE), surface area, volume, and volume of interstitial space (i.e., the space between branches). 3D-model based measures of TLE were highly similar to by-hand measurements made in the field (r = 0.98), demonstrating that this method is compatible with established techniques without additional in water effort. However, we identified an allometric relationship between the change in TLE and the volume of interstitial space, indicating that growth in higher order traits is not necessarily a linear function of growth in branch length. Additionally, relationships among growth measures weakened when comparisons were made across time points, implying that the use of early growth to predict future performance is limited. Taken together, results show that 3D photogrammetry is an information rich method for quantifying colony-level growth and its application can help address contemporary questions in coral biology.

2003 ◽  
Vol 33 (1) ◽  
pp. 164-170 ◽  
Author(s):  
John D Marshall ◽  
Robert A Monserud

Specific leaf area (SLA), the ratio of projected leaf area to leaf dry mass, is a critical parameter in many forest process models. SLA describes the efficiency with which the leaf captures light relative to the biomass invested in the leaf. It increases from top to bottom of a canopy, but it is unclear why. We sampled stands with low and elevated canopies (young and old stands) to determine whether SLA is related to water potential, as inferred from branch height and length, or shade, as inferred from branch position relative to the rest of the canopy, or both. We studied western white pine (Pinus monticola Dougl. ex D. Don), ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.), and interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca) in northern Idaho. SLA decreased with branch height (P < 0.0001) at rates that varied among species (P < 0.0001). Branch length had no influence on SLA (P = 0.85). We detected no differences with canopy elevation (P = 0.90), but the slopes of lines relating SLA to branch height may have differed between the canopy elevation classes (P = 0.039). The results are consistent with predictions based on the hypothesis that SLA decreases as the gravitational component of water potential falls. The lack of a strong shading effect simplifies the estimation of canopy SLA for process models, requiring only species and branch heights.


2018 ◽  
Vol 29 (2) ◽  
pp. 275
Author(s):  
Ricardo Vinicio Abril Saltos ◽  
Tomás Elías Ruiz Vázquez ◽  
Jatnel Alonso Lazo ◽  
Génova Marjorie Cabrera Murillo ◽  
Olivier Angel Meric

Agriculture has been one of the causes of deforestation, causing environmental impact and soil degeneration, which leads to lower income earned by farmers; hence the need to implement agroforestry systems .This research aims to describe fromthe initial growth of Eugenia stipitata, Inga edulis, and Inga spectabilis to 320 days after emergence. The study took place at the Amazon Research and Conservation Center of the Amazonas State University, during 2014 and 2015. The growth process was evaluated in regards to plant height, stem diameter, number of leaves, and branch length. Plant height and stem diameter were compared over time applying variance analysis. Precipitation was also compared to analyze whether its variations had a direct influence on plant growth. The linear and polynomial models fitted better for thespecies regarding plant height and sprout diameter. Predominance of green leaves compared to yellow and dry ones, as branch length showed significant differences over all the sampling periods. The two-way analysis of variance showed significant differences in the correlation between age and precipitation over plant height and stem diameter. The outcomes led to conclude that Eugenia stipitata had a lower growth than both Inga edulis and Inga spectabilis. Branch production and growth and the number of leaves were also important elements of the growth process.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252593
Author(s):  
Ian R. Combs ◽  
Michael S. Studivan ◽  
Ryan J. Eckert ◽  
Joshua D. Voss

Since 2014, stony coral tissue loss disease (SCTLD) has contributed to substantial declines of reef-building corals in Florida. The emergence of this disease, which impacts over 20 scleractinian coral species, has generated a need for widespread reef monitoring and the implementation of novel survey and disease mitigation strategies. This study paired SCTLD prevalence assessments with colony-level monitoring to help improve understanding of disease dynamics on both individual coral colonies and at reef-wide scales. Benthic surveys were conducted throughout the northern Florida Reef Tract to monitor the presence/absence of disease, disease prevalence, and coral species affected by SCTLD. Observed SCTLD prevalence was lower in Jupiter and Palm Beach than in Lauderdale-by-the-Sea or St. Lucie Reef, but there were no significant changes in prevalence over time. To assess colony-level impacts of the disease, we optimized a low-cost, rapid 3D photogrammetry technique to fate-track infected Montastraea cavernosa coral colonies over four time points spanning nearly four months. Total colony area and healthy tissue area on fate-tracked colonies decreased significantly over time. However disease lesion area did not decrease over time and was not correlated with total colony area. Taken together these results suggest that targeted intervention efforts on larger colonies may maximize preservation of coral cover. Traditional coral surveys combined with 3D photogrammetry can provide greater insights into the spatiotemporal dynamics and impacts of coral diseases on individual colonies and coral communities than surveys or visual estimates of disease progression alone.


2016 ◽  
Vol 74 (4) ◽  
pp. 1103-1112 ◽  
Author(s):  
Hayley E. Bedwell-Ivers ◽  
Marguerite S. Koch ◽  
Katherine E. Peach ◽  
Luke Joles ◽  
Elizabeth Dutra ◽  
...  

Previous studies suggest uniform reductions in coral calcification under ocean acidification (OA); however, greater tolerance has been observed under natural diel metabolic signals present on reefs. In addition, few studies have examined the role of in hospite zooxanthellae energetics on coral OA tolerance. In this study, we examined zooxanthellae photosynthesis and coral calcification responses using seawater with natural metabolic dissolved inorganic carbon (DIC) dynamics from a fringing back reef on Little Cayman Island, Caribbean. The experimental design included Acropora cervicornis and Porites divaricata microcolonies grown in continuously flowing seawater with (∼1000 μatm) and without (∼500 μatm) CO2 enrichment to year 2100 predicted levels. Calcification rates were measured weekly, while linear extension and zooxanthellae photosynthesis were determined at the termination of the 28 d experiment. Results showed A. cervicornis microcolonies maintained both photosynthesis and calcification under elevated CO2 partial pressure (pCO2) relative to controls. However, photosynthesis and calcification rates of P. divaricata microcolonies were reduced by ∼80 and 20%, respectively, under relatively high [DIC]:[H+] ratios and aragonite saturation states (Ωarag). Porites divaricata calcification response to elevated pCO2 was linked to photophysiological dysfunction of the algal symbiont, an indicator that this species was metabolically depressed under elevated pCO2. In contrast to calcification, linear extension rates were unaffected by pCO2 in both species. Future studies should investigate how elevated pCO2 may compromise zooxanthellae–coral interactions with an emphasis on DIC uptake pathways.


2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.


Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.


Author(s):  
Xianghong Tong ◽  
Oliver Pohland ◽  
J. Murray Gibson

The nucleation and initial stage of Pd2Si crystals on Si(111) surface is studied in situ using an Ultra-High Vacuum (UHV) Transmission Electron Microscope (TEM). A modified JEOL 200CX TEM is used for the study. The Si(111) sample is prepared by chemical thinning and is cleaned inside the UHV chamber with base pressure of 1x10−9 τ. A Pd film of 20 Å thick is deposited on to the Si(111) sample in situ using a built-in mini evaporator. This room temperature deposited Pd film is thermally annealed subsequently to form Pd2Si crystals. Surface sensitive dark field imaging is used for the study to reveal the effect of surface and interface steps.The initial growth of the Pd2Si has three stages: nucleation, growth of the nuclei and coalescence of the nuclei. Our experiments shows that the nucleation of the Pd2Si crystal occurs randomly and almost instantaneously on the terraces upon thermal annealing or electron irradiation.


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