scholarly journals Variation in Xylem Hydraulic Structure and Function of Two Mangrove Species across a Latitudinal Gradient in Eastern Australia

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 850
Author(s):  
Xin Jiang ◽  
Brendan Choat ◽  
Yong-Jiang Zhang ◽  
Xin-Yi Guan ◽  
Wen Shi ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Latitudinal Gradient ◽  
Hydraulic Structure ◽  
Structure And Function ◽  
Adaptive Plasticity ◽  
Hydraulic Efficiency ◽  
Mangrove Species ◽  
Eastern Australia ◽  
Embolism Resistance ◽  
And Function

Mangroves growing in tropical and subtropical intertidal zones face challenges from warming and altered rainfall patterns associated with global climate change. Intraspecific variation in hydraulic traits may allow a mangrove species to acclimate to novel climatic conditions, yet little is known regarding the potential for adaptive plasticity in these traits. In this study, we aimed to quantify the variation in plant hydraulic traits of two widespread mangrove species growing across a latitudinal gradient. We investigated the xylem hydraulic structure and function of Avicennia marina and Aegiceras corniculatum, across three sites spanning a latitudinal gradient of 17.45° in eastern Australia. We found that both species were highly resistant to xylem embolism and that there was significant intraspecific variation in hydraulic traits between sites. The highest embolism resistance and sapwood-specific hydraulic conductivity (KS) were found at the lowest latitude site that had the highest mean annual temperature and precipitation. A. marina showed no differences in vessel size and density among sites. It has other special features such as successive cambia enhancing its ability to adapt to a large environmental gradient. In contrast, A. corniculatum showed higher vessel densities at lower latitudes. There was a significant and positive correlation (R2 = 0.72, p < 0.05) between KS and embolism resistance across species and sites, suggesting the absence of a tradeoff between hydraulic efficiency and safety. Both embolism resistance and KS were negatively correlated with wood density but positively with vessel wall reinforcement. This study reveals that these two widespread mangrove species were adapted to warmer climates by enhancing both hydraulic efficiency and safety.

scholarly journals Sexual dimorphism in a top predator ( Notophthalmus viridescens ) drives aquatic prey community assembly

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181717 ◽  
Author(s):  
Denon Start ◽  
Stephen De Lisle
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Intraspecific Variation ◽  
Structure And Function ◽  
Sexually Dimorphic ◽  
Ecological Communities ◽  
Top Predator ◽  
Aquatic Mesocosms ◽  
And Function ◽  
The Impact

Intraspecific variation can have important consequences for the structure and function of ecological communities, and serves to link community ecology to evolutionary processes. Differences between the sexes are an overwhelmingly common form of intraspecific variation, but its community-level consequences have never been experimentally investigated. Here, we manipulate the sex ratio of a sexually dimorphic predacious newt in aquatic mesocosms, then track their impact on prey communities. Female and male newts preferentially forage in the benthic and pelagic zones, respectively, causing corresponding reductions in prey abundances in those habitats. Sex ratio differences also explained a large proportion (33%) of differences in the composition of entire pond communities. Ultimately, we demonstrate the impact of known patterns of sexual dimorphism in a predator on its prey, uncovering overlooked links between evolutionary adaptation and the structure of contemporary communities. Given the extreme prevalence of sexual dimorphism, we argue that the independent evolution of the sexes will often have important consequences for ecological communities.

Ecological role of grapsid crabs in mangrove ecosystems: a review

1998 ◽  
Vol 49 (4) ◽  
pp. 335 ◽  
Author(s):  
S. Y. Lee
Keyword(s):  
Organic Matter ◽  
Structure And Function ◽  
Mangrove Species ◽  
Organic Matter Production ◽  
Mangrove Ecosystems ◽  
Matter Production ◽  
Feeding Activities ◽  
And Function ◽  
Growth And Reproduction

Recent research on Indo–Pacific mangroves has confirmed the significant role played by grapsid crabs in the structure and function of these ecosystems. Through the feeding activities of the crabs, large proportions of organic matter production, i.e. mangrove leaves, are recycled within the forest. This initial retention of production in the forest refines earlier estimates of tidal export from the mangroves. Crab-processed organic matter could also form the basis of a coprophagous food chain involving small invertebrates, or be re-exported as micro-particulates. Differential consumption by crabs of mangrove propagules also affects mangrove community structure by diminishing the relative abundance of species whose propagules are preferred foods. Bioturbation by the crabs also results in changes in surface topography, particle size distribution and degree of aeration and, thus, the concentration of phytotoxins in the substratum. Such changes could affect growth and production of the mangroves. Growth and reproduction of the crabs may in turn be influenced by the associated mangrove species, mainly through the provision of food. The semi-terrestrial and air-breathing habit of the grapsid crabs probably makes them tolerant of deoxygenation caused by organic enrichment, but development of the landward mangroves will strongly affect survival of the crabs.

scholarly journals Pit and tracheid anatomy explain the hydraulic safety- but not the hydraulic efficiency of 28 conifer species

2021 ◽  
Author(s):  
Yanjun Song ◽  
Lourens Poorter ◽  
Angelina Horsting ◽  
Sylvain Delzon ◽  
Frank Sterck
Keyword(s):  
Hydraulic Conductivity ◽  
Vascular System ◽  
Common Garden ◽  
Hydraulic Efficiency ◽  
Conifer Species ◽  
Hydraulic Safety ◽  
Valve Effect ◽  
Embolism Resistance ◽  
Underlying Mechanisms ◽  
And Function

Abstract Conifers face increased drought mortality risks because of drought-induced embolism in their vascular system. Variation in embolism resistance may result from species differences in pit structure and function, as pits control the air seeding between water transporting conduits. This study quantifies variation in embolism resistance and hydraulic conductivity for 28 conifer species grown in a 50-year-old common garden experiment and assesses the underlying mechanisms. Conifer species with a small pit aperture, high pit aperture resistance and large valve effect were more resistant to embolism, as they all may reduce air seeding. Surprisingly, hydraulic conductivity was only negatively correlated with tracheid cell wall thickness. Embolism resistance and its underlying pit traits related to pit size and sealing were stronger phylogenetically controlled than hydraulic conductivity and anatomical tracheid traits. Conifers differed in hydraulic safety and hydraulic efficiency, but there was no trade-off between safety and efficiency because they are driven by different xylem anatomical traits that are under different phylogenetic control.

Biophysical Perspectives of Xylem Evolution: is there a Tradeoff of Hydraulic Efficiency for Vulnerability to Dysfunction?

IAWA Journal ◽  
1994 ◽  
Vol 15 (4) ◽  
pp. 335-360 ◽  
Author(s):  
Melvin T. Tyree ◽  
Stephen D. Davis ◽  
Hervè Cochard
Keyword(s):  
Water Transport ◽  
Negative Pressure ◽  
Structure And Function ◽  
Land Plants ◽  
Air Bubbles ◽  
Hydraulic Efficiency ◽  
Xylem Structure ◽  
Vessel Lumen ◽  
Metastable Water ◽  
And Function

In this review, we discuss the evolution of xylem structure in the context of our current understanding of the biophysics of water transport in plants. Water transport in land plants occurs while water is under negative pressure and is thus in a metastable state. Vessels filled with metastable water are prone to dysfunction by cavitation whenever gas-filled voids appear in the vessel lumen. Cavitated vessels fill with air and are incapable of water transport until air bubbles dissolve. We know much more about how cavitations occur and the conditions under which air bubbles (embolisms) dissolve. This gives us an improved understanding of the relations hip between xylem structure and function.

Functional morphology of the balanomorph barnacles Tesseropora rosea (Krauss) and Tetraclitella purpurascens (Wood) (Tetraclitidae)

1985 ◽  
Vol 36 (1) ◽  
pp. 87 ◽  
Author(s):  
DT Anderson ◽  
JT Anderson
Keyword(s):  
Structure And Function ◽  
Minor Role ◽  
Rocky Shores ◽  
Water Currents ◽  
The Third ◽  
Extended Position ◽  
Eastern Australia ◽  
Respiratory Pumping ◽  
And Function ◽  
Small Valve

Tesseropora rosea of eastern Australia inhabits exposed, wave-washed rocks, is an extension feeder in fast currents, and has monometric growth, with orifice enlargement by erosion. It has a deep, mobile operculum. Tergal depressor muscles are large, scutal depressors moderately large. The opercular valves play an active part in respiratory pumping beat. Tergal depressors effect opercular withdrawal. Rostral scutal depressors assist in pumping beat. Lateral scutal depressors assist in opercular opening. Cim IV-VI of T. rosea unfurl rapidly in response to fast water currents and are captorial, either singly or in concert. The antenniform third maxillipeds (cirrus 111) turn back laterally in the extended position but fold over and hold down the captorial cirri in the curled position. Tetraclitella purpurascens of southern Australia inhabits crevices and overhangs on rocky shores, is an extension feeder in moderate currents, and has diametric growth, with orifice enlargement by circumferential growth of radii and parietes. It has a shallow operculum with only slight mobility. Tergal depressors are large, scutal depressors small. Valve action is mainly hinge-like and slow, with little apicobasal movement. The small scutal depressors assist the large tergal depressors in opercular withdrawal and have only a very minor role in pumping beat. Cirri IV-VI of T. purpurascens are held erect for long periods in moderate water currents. Captorial movements are similar to but slower than those of T. rosea. The third maxillipeds have short rami involved in forward food transfer. Setation correlates with function on the cirri of both species. The oral cone of T. rosea is broader and the mouthparts relatively larger than those of T. purpurascens, possibly mediating a more powerful triturating mechanism. A comparison of structure and function shows that T. purpurascens retains many primitive balanomorph features, whereas T. rosea has a more advanced functional configuration. In the evolution of tetraclitids, it seems likely that the tetraclitellines diverged early, before the austrobalanines gave rise to the tetraclitines. The four-plated wall may have evolved independently in tetraclitellines and austrobalanines.

Evidence that branches of evergreen angiosperm and coniferous trees differ in hydraulic conductance but not in Huber values

2007 ◽  
Vol 85 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Christopher H. Lusk ◽  
Mylthon Jiménez-Castillo ◽  
Nicolás Salazar-Ortega
Keyword(s):  
Leaf Area ◽  
Rain Forest ◽  
Temperate Forests ◽  
Hydraulic Conductance ◽  
Structure And Function ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Hydraulic Efficiency ◽  
Cross Sectional ◽  
And Function

The hydraulic efficiency conferred by vessels is regarded as one of the key innovations explaining the historical rise of the angiosperms at the expense of the gymnosperms. Few studies, however, have compared the structure and function of xylem and their relationships with foliage traits in evergreen representatives of both groups. We measured sapwood cross-sectional area, conduit diameters, hydraulic conductance, and leaf area of fine branches (2.5–7.5 mm diameter) of five conifers and eight evergreen angiosperm trees in evergreen temperate forests in south-central Chile. Conductance of both lineages was higher at Los Lleuques, a warm temperate site with strong Mediterranean influence, than in a cool temperate rain forest at Puyehue. At a common sapwood cross-sectional area, angiosperm branches at both sites had greater hydraulic conductance (G) than conifers, but similar leaf areas. Branch conductance normalized by subtended leaf area (GL) at both sites was, therefore, higher in angiosperms than in conifers. Hydraulically weighted mean conduit diameters were much larger in angiosperms than in conifers, although this difference was less marked at Puyehue, the cooler of the two sites. Conduits of the vesselless rain forest angiosperm Drimys winteri J.R. & G. Forst were wider than those of coniferous associates, although narrower than angiosperm vessels. However, GL of D. winteri was within the range of values measured for vesselbearing angiosperms at the same site. The observed differences in xylem structure and function correlate with evidence that evergreen angiosperms have higher average stomatal conductance and photosynthetic capacity than their coniferous associates in southern temperate forests. Comparisons of conifers and angiosperm branches thus suggest that the superior capacity of angiosperm conduits is attributable to the development of higher gas-exchange rates per unit leaf area, rather than to a more extensive leaf area. Results also suggest that the tracheary elements of some vesselless angiosperms differ in width and hydraulic efficiency from conifer tracheids.

Consequences of intraspecific variation for the structure and function of ecological communities Part 2: Linking diversity and function

2007 ◽  
Vol 207 (2-4) ◽  
pp. 277-285 ◽  
Author(s):  
Elizaveta Pachepsky ◽  
James L. Bown ◽  
Alistair Eberst ◽  
Ursula Bausenwein ◽  
Peter Millard ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Structure And Function ◽  
Ecological Communities ◽  
And Function

Consequences of intraspecific variation for the structure and function of ecological communities

2007 ◽  
Vol 207 (2-4) ◽  
pp. 264-276 ◽  
Author(s):  
James L. Bown ◽  
Elizaveta Pachepsky ◽  
Alistair Eberst ◽  
Ursula Bausenwein ◽  
Peter Millard ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Structure And Function ◽  
Ecological Communities ◽  
And Function

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

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