Anatomical aspects of xeromorphy in arid-adapted plants of Australia

2020 ◽  
Vol 68 (3) ◽  
pp. 245 ◽  
Author(s):  
V. M. Dörken ◽  
P. G. Ladd ◽  
R. F. Parsons
Keyword(s):  
Close Association ◽  
Arid Environments ◽  
Arid Areas ◽  
Tissue Formation ◽  
Terrestrial Plants ◽  
Shrub Species ◽  
Structural Support ◽  
Dry Conditions ◽  
Broad Leaved Species ◽  
Sclerophyllous Plants

Plants from arid environments have some of the most diverse morphological and anatomical modifications of any terrestrial plants. Most perennials are classified as xerophytes, and have structures that limit water loss during dry weather, provide structural support to help prevent cell collapse during dry periods or store water in photosynthetic tissues. Some of these traits are also found in sclerophyllous plants and traits that may have developed due to evolution of taxa on nutrient poor soils may also benefit the plants under arid conditions. We examined the morpho-anatomical features of photosynthetic organs of three tree and four shrub species with reduced leaves or photosynthetic stems that occur in arid or semiarid sites in Australia to see if there were patterns of tissue formation particularly associated with xeromorphy. In addition, we reviewed information on succulent and resurrection species. In the tree species (Callitris spp.) with decurrent leaves clothing the stems, the close association between the water transport system and stomata, along with anisotropic physiology would allow the species to fix carbon under increasingly dry conditions in contrast to more broad-leaved species. The shrub species (Tetratheca species and Glischrocaryon flavescens) with photosynthetic stems had extensive sclerenchyma and very dense chlorenchyma. The lack of major anatomical differences between leafless species of Tetratheca from arid areas compared with more mesic sites indicates that quite extreme morphological modifications may not exclude species from growing successfully in competition with species from less arid areas. The sclerophyll flora now characteristic of Australian vegetation from seasonally arid climates may have evolved during mesic times in the past but with relatively minor modifications was able to adjust to the gradually drying climate of much of Australia up to the present time.

Terrestrial plants and marine algae from the Late Jurassic lithographic limestone of the Causse Méjean (Lozère, southern France)

2016 ◽  
Vol 187 (2) ◽  
pp. 121-127
Author(s):  
Jean-David Moreau ◽  
Louis Baret ◽  
Gérard Lafaurie ◽  
Carmela Chateau-Smith
Keyword(s):  
Late Jurassic ◽  
Marine Algae ◽  
Coastal Areas ◽  
Land Plants ◽  
Fossil Plants ◽  
Terrestrial Plants ◽  
Southern France ◽  
Lithographic Limestone ◽  
Dry Conditions ◽  
Marine Lagoon

Abstract A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Méjean, Lozère (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a flat, homogeneous, protected environment, perhaps a brackish or marine lagoon, influenced by both continental and marine inputs. This discovery complements the few existing reports of European Late Jurassic floras, and indicates that coastal habitats were dominated by sub-arborescent vegetation, consisting of bennettitaleans and pteridosperms, and arborescent plants, such as conifers. Both the palaeoenvironmental context and certain xerophytic features suggest that these terrestrial plants from the Causse Méjean were well adapted to the hot, dry conditions of coastal areas.

Distribution of fluvial sediment yields in hyper-arid areas, exemplified by Nahal Nehushtan, Israel 

2021 ◽  
Author(s):  
Rachel Armoza-Zvuloni ◽  
Yanai Shlomi ◽  
Itay Abadi ◽  
Rachamim Shem-Tov ◽  
Jonathan B. Laronne
Keyword(s):  
Sediment Yield ◽  
Flash Flood ◽  
Flood Frequency ◽  
Drainage Area ◽  
Stratigraphic Correlation ◽  
Rain Event ◽  
Arid Environments ◽  
Arid Areas ◽  
Fluvial Sediment ◽  
Sediment Yields

<p>Floods rarely occur in hyper-arid deserts and little is known about the magnitude and frequency of sediment delivery from their basins, despite their importance to changes to the landscape as well as to infrastructures and engineering activities. Sediment yield from the Nahal Nehushtan watershed (15.7 km<sup>2</sup>) located in the Timna Valley in southern Israel, was determined by assessing stratigraphic sections in its 60-year reservoir deposits. Stratigraphic correlation between event couplets allowed quantification of sediment yields representing 13 former flash-flood events. Based on the sediment volume in the reservoir, the 24.6 t km<sup>-2</sup> y<sup>-1</sup> average sediment yield is the lowest among other studied warm deserts. Among the event layers, five are voluminously small and seven are medium-sized. The thickest layer, deposited by a flash flood caused by a single short rain event, contributed 29% of the total sediment yield. This demonstrates the overarching effect of medium magnitude events on the rate of sediment production in a hyper-arid setting. Based on event reservoir sedimentation from watersheds located in several hyper-arid areas in the Middle East and North America, sediment load increases with drainage area as expected; however, sediment yield does not decrease with drainage area, as was shown for arid environments. Overall, mean annual sediment yield is very low and increases with flood frequency, with considerable variation generated by local characteristics. Our quantitative results together with previous studies of hyper-arid areas, provide complementary evidence of fluvial sediment transport - the main landscape designer in fluvial desert landscapes.</p>

First evidence of prehistoric humans-induced fire in India: clues from macro-charcoal, biomarkers distribution and compound-specific stable isotopes

2020 ◽  
Author(s):  
Deepak Kumar Jha ◽  
Rahul Samrat ◽  
Prasanta Sanyal
Keyword(s):  
Close Association ◽  
Fire Disturbance ◽  
Short Chain ◽  
Anthropogenic Factors ◽  
Archaeological Sites ◽  
Average Chain Length ◽  
Agricultural Activity ◽  
Ecosystem Structure ◽  
Terrestrial Plants ◽  
Fire Event

<p>Fire disturbance appears to be one of the vital processes in shaping vegetation composition and landscape dynamics of an area. It is an essential driver of ecosystem structure, in close association with environmental conditions. Environmental factors, as well as human, can equally induce the fire at the stand. Untying the natural vs. anthropogenic factors is important to comprehend the paleoclimatic conditions at a regional and global scale. Therefore, identifying the fire events from chronologically well-constrained archaeological sites would provide an ideal opportunity to decode its cause and impact on the terrestrial environment. Hence, the present study is conducted on the fluvial cliff sections, which preserved the tools and artefacts from Lower Paleolithic (~100 ka) to Neolithic (~3 ka) phases in the Belan valley, north-central India.</p><p>In this study, paleosols samples (n=49) were collected from six sedimentary sections of archaeological sites. Paleosols were analysed for <em>n</em>-alkane distribution pattern, <em>n</em>-alkane ratio (C<sub>16</sub>/C<sub>29</sub> and C<sub>16</sub>/C<sub>31</sub>), δD<em><sub>n</sub></em><sub>-alkane </sub>values, δ<sup>13</sup>C<em><sub>n</sub></em><sub>-alkane</sub> values and macro-charcoal (CHAR) to reconstruct the vegetation, climate and fire events. The n-alkane (C<sub>15</sub> to C<sub>35</sub>) distribution signature, average chain length (ACL<sub>15-33</sub>) and carbon preference index (CPI<sub>25-33</sub>) values are used to distinguish the aquatic vs. terrestrial contribution in the organic matter (OM). The higher CPI<sub>25-33 </sub>and ACL<sub>15-33</sub> values suggest terrestrial plants derived OM dominance in the paleosols. Four samples with lower CPI<sub>25-33</sub> (~1.0) and ACL<sub>15-33</sub> (~23.0) suggests higher degradation of OM. Moreover, the lower CPI<sub>25-33</sub> samples also showed a dominance of short-chain even-numbered alkanes (maximum at C<sub>16</sub> or C<sub>18</sub>). A similar observation in short-chain <em>n</em>-alkanes was reported from the archaeological site with known fire events (Eckmeier and Wiesenberg, 2009). Also, the CHAR analyses (n=40) suggests that the degraded paleosols (lower CPI and ACL) have suffered thermal alteration. The CHAR and <em>n</em>-alkane ratio suggest paleofire events in the Belan valley during i) ~100 to 95 ka, ii) ~60 to 55 ka, iii) ~42 to 37 ka, iv) ~26 to 20 ka and v) ~8 to 3 ka. δD<em><sub>n</sub></em><sub>-alkane</sub> values suggested lower rainfall conditions during Large Glacial Maximum (LGM; ~25 to 18 ka). The intensification in rainfall observed during i) ~100 to 75 ka and iii) ~18 to 3 ka, which also corresponds to some fire events. The δ<sup>13</sup>C<em><sub>n</sub></em><sub>-alkane</sub> values suggest the dominance of grassland during LGM, which was favourable for wildfires. Further, the fire event during ~26 to 20 ka identified at Main Belan temporarily overlays with Mahagara and Koldihwa site. The lack of any significant signature of thermal degradation of paleosols (supported by <em>n</em>-alkanes) in Koldihwa and Mahagara suggests the extra-local nature of the fire. The higher rainfall is an unfavourable condition for natural wildfires. Further, the fire disturbance increases in the early-Holocene, which overlaps with the timing of high rainfall condition and agricultural activity in the Belan valley. Therefore, this study postulates that the prehistoric humans-induced fire from ~60 ka onwards.</p><p>Eckmeier, E. and Wiesenberg, G.L., 2009. Short-chain <em>n</em>-alkanes (C16–20) in ancient soil are useful molecular markers for prehistoric biomass burning. Journal of Archaeological Science, 36(7), 1590-1596.</p>

scholarly journals Laparoscopic Vaginoplasty Procedure Using a Modified Peritoneal Pull-Down Technique with Uterine Strand Incision in Patients with Mayer–Rokitansky–Küster–Hauser Syndrome: Kisu Modification

2021 ◽  
Vol 10 (23) ◽  
pp. 5510
Author(s):  
Iori Kisu ◽  
Miho Iida ◽  
Kanako Nakamura ◽  
Kouji Banno ◽  
Tetsuro Shiraishi ◽  
...  
Keyword(s):  
Case Series ◽  
Tissue Formation ◽  
Granulation Tissue Formation ◽  
Mrkh Syndrome ◽  
Structural Support ◽  
Age At Surgery ◽  
The Mean ◽  
Safe Approach ◽  
Anatomical Success

Various vaginoplasty procedures have been developed for patients with Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome. Here, we describe a novel laparoscopic vaginoplasty procedure, known as the Kisu modification, using a pull-down technique of the peritoneal flaps with additional structural support to the neovaginal apex using the incised uterine strand in patients with MRKH syndrome. Ten patients with MRKH syndrome (mean age at surgery: 23.9 ± 6.5 years, mean postoperative follow-up period: 17.3 ± 3.7 months) underwent construction of a neovagina via laparoscopic vaginoplasty. All surgeries were performed successfully without complications. The mean neovaginal length at discharge was 10.3 ± 0.5 cm. Anatomical success was achieved in all patients, as two fingers were easily introduced, the neovagina was epithelialized, and the mean neovaginal length was 10.1 ± 1.0 cm 1 year postoperatively. No obliteration, granulation tissue formation at the neovaginal apex, or neovaginal prolapse was recorded. Five of the 10 patients attempted sexual intercourse and all five patients were satisfied with the sexual activity, indicating functional success. Although the number of cases in this case series is few, our favorable experience suggests that the Kisu modification of laparoscopic vaginoplasty procedure is an effective, feasible, and safe approach for neovaginal creation in patients with MRKH syndrome.

scholarly journals Evaluation and Distribution of Onagraceae Species in the Texas Panhandle and Texas South Plains

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 670a-670
Author(s):  
Sandra A. Balch ◽  
Cynthia B. McKenney ◽  
Dick L. Auld
Keyword(s):  
Native Species ◽  
Oil Content ◽  
Arid Environments ◽  
Oenothera Biennis ◽  
Evening Primrose ◽  
Distribution Maps ◽  
Texas Panhandle ◽  
Dry Conditions ◽  
Gravelly Soils ◽  
Commercial Sources

Oenothera biennis, common evening primrose, produces seeds that have a high oil content containing gamma-linolenic acid (GLA), a fatty acid of medicinal, and dietary importance. These plants are commonly found in sandy or gravelly soils and have the ability to tolerate hot, dry conditions. Plants containing economically important oils such as GLA are potential crops for arid environments with minimal irrigation. Many native species of evening primrose have not yet been evaluated for oil content. In this project, a systematic survey of native Onagraceae species was conducted in the Texas Panhandle and the Texas South Plains. Six species of Oenothera and two species of Calylophus were found. Locations were recorded with a Global Positioning System (GPS) to facilitate relocation and collection. Distribution maps were made for each species. The occurrence of species varied greatly from north to south, with the exception of one species that occurred throughout the area surveyed. Seeds were collected from each species and from various locations within the range of each species. Germination percentages were determined for each species and had a wide variation. Evaluation of the oil content of this native germplasm could possibly lead to development of new commercial sources of GLA.

Surviving in semi-arid environments: functional coordination and trade-offs in shrubs from Argentina

IAWA Journal ◽  
2021 ◽  
pp. 1-19
Author(s):  
Natalia Delbón ◽  
Lucía V. Castello ◽  
Alejandro Rios-Villamil ◽  
María T. Cosa ◽  
Laura Stiefkens
Keyword(s):  
Small Diameter ◽  
Leaf Traits ◽  
Human Action ◽  
Survival Strategies ◽  
Arid Environments ◽  
Leaf Trait ◽  
Seasonally Dry ◽  
Trade Offs ◽  
Dry Conditions ◽  
Wood Traits

Abstract Human action has led to an increase in aridification, making water a progressively scarcer resource. In angiosperms, different species resolve this challenge in diverse ways, mainly through modifications of the xylem network, which is responsible for water efficiency and safety. Xerophytes generally show similar characteristics, but exceptions are rather frequent. One possible explanation for this lack of similarity among cohabiting species is that trade-offs and/or functional coordination between their organs occur and shape alternative survival strategies. Studying species that inhabit a common area can help to identify key traits that determine those diverse strategies and to predict which species might tolerate further environmental change. We here examined the morpho-anatomical wood and bark traits of a group of species that live in a seasonally dry environment in Argentina. In a previous study, we described the leaf traits of these species and we thus aim to complement our findings and outline their strategies to manage water deficits. Our results show that there are different degrees of xeromorphism within this group. Clear xeromorphic traits, such as high vessel frequency and small diameter, were found in most species. However, some presented traits that were appropriate for mesic environments. An overview of leaf and wood traits indicates that the absence of a typical xeric characteristic in the wood might be compensated by the presence of a xeric leaf trait, and vice versa. Collectively, these trait combinations allow these species to survive in dry conditions and could influence their tolerance to increasing aridity.

Stable-isotope paleoclimate records for southern Ontario, Canada: comparison of results from marl and wood

1988 ◽  
Vol 25 (9) ◽  
pp. 1397-1406 ◽  
Author(s):  
T. W. D. Edwards ◽  
P. Fritz
Keyword(s):  
Meteoric Water ◽  
Terrestrial Plants ◽  
Southern Ontario ◽  
Midwest United States ◽  
Water Composition ◽  
Dry Conditions ◽  
Evaporative Enrichment ◽  
Paleoclimate Records ◽  
Data Yield

Profiles of δ18O in two marl cores from southern Ontario, Canada, are compared in detail with the records of meteoric water isotopic composition and photosynthetic humidity obtained from previous isotopic studies using wood cellulose at Brampton, Ontario. By accounting for the inferred changes in meteoric water composition and temperature, the changes in the oxygen-isotope content of the marl arising from fluctuations in the evaporative enrichment of the lakewater can be estimated. The resulting synthetic profiles of relative evaporative enrichment from both marl cores exhibit strong correspondence to the photosynthetic humidity profile generated from the studies at Brampton, which substantiates the importance of evaporation in the water budgets of these two lakes. A striking analogy exists between the isotopic evaporative enrichment response of such lakewaters and that of the waters in terrestrial plants; both of the marl lakes approach close to isotopic steady state during the summer season, when carbonate precipitation occurs.The results of these studies strengthen the basis for paleoclimatic interpretations suggested in previous reports. Most notably, the marl data yield further evidence for relatively dry conditions in southern Ontario during the early part of the Hypsithermal interval, at a time that coincides with maximum eastward extension of prairie in the midwest United States.

scholarly journals Above and belowground carbon pools are affected by dominant floral species in hyper-arid environments

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1043
Author(s):  
Taoufik S. Ksiksi ◽  
Rebecca Trueman ◽  
Mahmoud Abdelfattah ◽  
Mohamed Taher Mousa ◽  
Abdullah Yousif Almarzouqi ◽  
...  
Keyword(s):  
Good Reason ◽  
Arid Environment ◽  
Arid Environments ◽  
Desert Ecosystems ◽  
Shrub Species ◽  
C Storage ◽  
C Pools ◽  
Below Ground ◽  
Belowground Carbon ◽  
Average Contribution

Introduction: Carbon (C) pools in desert ecosystems have not been well investigated, especially in relation to quantitative assessment for different compartments. In many ecosystems C uptake may increase, which leads to accelerated C cycling belowground. Methods: Therefore there is a strong need for C storage in compartments such as phytomass and/or within soils. In the present study we assessed C pools of different soil/vegetation associations as affected by the dominant tree and shrub species. Results: Mountain valleys had the highest C pool in the phytomass compartment with an average of 3.6 tons per hectare, of which 1.32 tons per hectare were contained aboveground. The introduced Prosopis juliflora had by far the highest average contribution of 3.47 tons of C per hectare. Most of which is in the above ground parts (83.3%) and the remaining is sequestered below ground. Halopeplis perfoliata, however, contributed the least C to the desert systems of the UAE. Some land forms, such as mountain valleys, were shown to sequester more C than others, which constitute a good reason to improve their conditions. Conclusions: Few shrub/tree species, such as P. juliflora, were also reported to have high potentials as a C pool in the hyper-arid environment of the UAE.

scholarly journals Status and Diversity of Terrestrial plants in Ghodaghodi Lake Complex, Nepal

2021 ◽  
Vol 9 (1) ◽  
pp. 38-44
Author(s):  
Ramesh Bhandari ◽  
Mahamad Sayab Miya ◽  
Sachin Timilsina
Keyword(s):  
Tree Species ◽  
Hot Spot ◽  
Terrestrial Plants ◽  
Shrub Species ◽  
The Family ◽  
The Status ◽  
Aerva Lanata ◽  
The Right ◽  
Important Value Index ◽  
Herb Species

Among the Ramsar sites of Nepal, Ghodaghodi Lake Complex (GLC) is a biodiversity hot spot. This study was carried out to assess the status and diversity of terrestrial plants in GLC. Employing purposive sampling, altogether 38 plots were taken along the right hand side of the foot trails around the GLC. Collected data were analyzed using formulas and Important Value Index (IVI) was calculated. A total of 50 terrestrial species from 27 families were recorded, among which 35 were trees, 8 shrubs, and 7 herbs. Terminalia tomentosa (Saj) has highest IVI (46.53) among tree species. Similarly, Aerva lanata (Khari) has highest IVI (54.13) among herb species and Calotropis gigantea (Aank) has highest IVI (68.56) among the shrub species. The family Fabaceae family (n=7) represented the maximum numbers of plants species followed by Moraceae family. Int. J. Appl. Sci. Biotechnol. Vol 9(1): 38-44

scholarly journals Pectin-Based Scaffolds for Tissue Engineering Applications

2021 ◽  
Author(s):  
Anna Lapomarda ◽  
Aurora De Acutis ◽  
Carmelo De Maria ◽  
Giovanni Vozzi
Keyword(s):  
Tissue Engineering ◽  
Wound Healing ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Tissue Formation ◽  
Fabrication Technology ◽  
Engineering Applications ◽  
Structural Support ◽  
Interdisciplinary Field ◽  
Alternative Approaches

Tissue engineering (TE) is an interdisciplinary field that was introduced from the necessity of finding alternative approaches to transplantation for the treatment of damaged and diseased organs or tissues. Unlike the conventional procedures, TE aims at inducing the regeneration of injured tissues through the implantation of customized and functional engineered tissues, built on the so-called ‘scaffolds’. These provide structural support to cells and regulate the process of new tissue formation. The properties of the scaffold are essentials, and they can be controlled by varying the biomaterial formulation and the fabrication technology used to its production. Pectin is emerging as an alternative biomaterial to non-degradable and high-cost petroleum-based biopolymers commonly used in this field. It shows several promising properties including biocompatibility, biodegradability, non-toxicity and gelling capability. Pectin-based formulations can be processed through different fabrication approaches into bidimensional and three-dimensional scaffolds. This chapter aims at highlighting the potentiality in using pectin as biomaterial in the field of tissue engineering. The most representative applications of pectin in preparing scaffolds for wound healing and tissue regeneration are discussed.

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