Determining the factors affecting seed germination in Livistona australis (Arecaceae) for the recovery of fragmented populations

2012 ◽  
Vol 60 (7) ◽  
pp. 575 ◽  
Author(s):  
Nicholas Carlile ◽  
David Priddel ◽  
Tony D. Auld ◽  
David A. Morrison
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seed Viability ◽  
Factors Affecting ◽  
Light Levels ◽  
In Situ Experiments ◽  
Germination Success ◽  
Buried Seed ◽  
Potential Success

Understanding seed germination and seedling recruitment is important for managing long-lived plant species, particularly palms that are transplanted from the wild and where regeneration is suppressed by seed predators and exotic herbivores. Seed viability, the timing of germination, and the factors influencing germination were investigated for the cabbage tree palm, Livistona australis (R.Br.) Mart. Greenhouse studies were combined with in situ experiments conducted on the Australian mainland and on a nearby mammal-free island. Under greenhouse conditions, >90% of seed germinated within 4 months. In the field, burial rather than surface sowing of seed increased germination success. Seed without mesocarp and in sunlight had increased germination when compared with fruits in shade on the island, whereas neither presence/absence of mesocarp or light levels had any effect on the mainland. Germination success was substantially lower on the mainland, primarily because of high seed predation from the native bush rat, Rattus fuscipes. When caged to exclude vertebrates, 44% of seed were damaged over time by pathogens and invertebrates, with losses greater in sunlight than in shade. Results from the present study indicate that freshly buried seed with the mesocarp removed would have the greatest potential success in promoting the restoration of L. australis at degraded sites.

scholarly journals Factors affecting arsenic mobility from hydrothermally altered rock in impoundment-type in situ experiments

2010 ◽  
Vol 23 (3) ◽  
pp. 238-248 ◽  
Author(s):  
Carlito B. Tabelin ◽  
Toshifumi Igarashi ◽  
Shuichi Tamoto
Keyword(s):  
Altered Rock ◽  
Factors Affecting ◽  
Arsenic Mobility ◽  
In Situ Experiments

Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 854-860 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Gurjeet Gill ◽  
Christopher Preston
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Field Experiments ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Factors Affecting ◽  
Control Programs ◽  
Buried Seed ◽  
Ph Range

Annual sowthistle has become more abundant under no-till systems in southern Australia. Increased knowledge of germination biology of annual sowthistle would facilitate development of effective weed control programs. The effects of environmental factors on germination and emergence of annual sowthistle seeds were examined in laboratory and field experiments. Seeds of annual sowthistle were able to germinate over a broad range of temperatures (25/15, 20/12, and 15/9 C day/night temperatures). Seed germination was favored by light; however, some germination occurred in the dark as well. Greater than 90% of seeds germinated at a low level of salinity (40 mM NaCl), and some seeds germinated even at 160 mM NaCl (7.5%). Germination decreased from 95% to 11% as osmotic potential increased from 0 to −0.6 MPa and was completely inhibited at osmotic potential greater than −0.6 MPa. Seed germination was greater than 90% over a pH range of 5 to 8, but declined to 77% at pH 10. Seedling emergence was the greatest (77%) for seeds present on the soil surface but declined with depth, and no seedlings emerged from a soil depth of 5 cm. In another experiment in which seeds were after-ripened at different depths in a field, seed decay was greater on the soil surface than at 2 or 5 cm depth. At the end of the growing season, there was a much greater persistence of buried seed (32 to 42%) than seeds present on the soil surface (8%). Greater persistence of buried seed could be due to dormancy enforced by dark in this species.

scholarly journals Factors affecting germination and establishment success of an endemic cactus of the Chihuahuan Desert

2020 ◽  
Author(s):  
Eder Ortiz-Martínez ◽  
Jordan Golubov ◽  
María C. Mandujano ◽  
Gabriel Arroyo-Cosultchi
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Developmental Stages ◽  
Seedling Recruitment ◽  
Chihuahuan Desert ◽  
Exclusion Experiment ◽  
Factors Affecting ◽  
Nurse Plants ◽  
Predator Exclusion ◽  
Storage Times

AbstractSeed and seedling are the most critical stages of cacti life cycle. From the thousands of seeds produced in a reproductive season, only a small fraction gets to germinate, the rest gets lost due to predation or gets potentially buried in the seed bank. These early stages depend on facilitation by nurse plants for germination and seedling recruitment. In this paper, we aim to describe some aspects of the recruitment of Cephalocereus polylophus. We tested the viability of seeds with different storage times as an indicator of their potential to form a short-term seed bank. Through the analysis of seed germination and seedlings survival under the canopy of two nurse plant species and open areas, we aimed to assess the importance of facilitation for recruitment. A predator exclusion experiment was used to evaluate the intensity of herbivory on seeds and seedlings of different developmental stages. Seeds had germination rates above 90%, even after two years of storage. Seed germination was only registered under one of the two nurses. After two years, up to 19% of the seedlings planted under both nurse plants survived. Protection against herbivores increased survival chances from 30 to 52 % for all age-group seedlings. Considering that facilitation is a crucial interaction for C. polylophus, future conservation programs should include the protection of plant communities.

Seed Germination and Seedling Recruitment Behavior of Winged Sea Lavender (Limonium lobatum) in Southern Australia

Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Samuel G. L. Kleemann ◽  
Gurjeet Gill
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Base Temperature ◽  
Weed Species ◽  
Factors Affecting ◽  
Weed Seeds ◽  
Sea Lavender ◽  
C 50

AbstractWinged sea lavender [Limonium lobatum(L.f. Chaz)] is emerging as a significant weed of field crops in southern Australia. Several environmental factors affecting germination and seedling recruitment were examined to provide a better understanding of the behavior of its seedbank. At maturity, weed seeds were dormant for a period of around 2 mo, but dormancy was easily broken with scarification or by pretreatment with 564 mM NaOCL for 30 min, which confirms the role of the seed coat in regulating seed germination. Exposure to light significantly increased germination. Seeds were able to germinate over a broad range of temperatures (5 to 30 C), with maximum germination (~92%) at temperatures between 10 and 30 C. At 20 to 25 C, 50% germination was reached within 1.3 to 2 d, and the predicted base temperature for germination of the two populations ranged from 1.4 to 3.9 C. The NaCl concentration required to inhibit germination by 50% was 230 mM, with some seeds capable of germination at salinity levels as high as 480 mM. These results indicated greater tolerance to salinity inL. lobatumthan many other Australian agricultural weed species previously investigated. Seedling emergence was the highest (51% to 57%) for seeds present on the soil surface and was significantly reduced by burial at 1 cm (≤11%) and 2 cm (≤2%), with no emergence at 5 cm. Under field conditions, seedling recruitment varied considerably among the three experimental sites. The level of seedling recruitment was negatively associated with rainfall received at the site, organic carbon (OC) level, and microbial biomass of the soil. Rapid decay of weed seeds in high-OC soils appears to be an important determinant of seedling recruitment in this species and could explain greater occurrence ofL. lobatumon soils with low OC and low microbial activity in low-rainfall areas of southern Australia. Furthermore, many such soils in southern Australia are affected by salinity, which would enableL. lobatumto be more competitive with crops and other weeds present at a site.

scholarly journals Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species

2019 ◽  
Vol 20 (3) ◽  
pp. 704-711
Author(s):  
KAROLINE APARECIDA FELIX RIBEIRO ◽  
CRISTIAN MADEIRA DE MEDEIROS ◽  
JOSÉ ÁNGEL SÁNCHEZ-AGUDO ◽  
JOSÉ SÁNCHEZ-SÁNCHEZ
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
Ex Situ Conservation ◽  
Seed Viability ◽  
Potassium Nitrate ◽  
Ex Situ ◽  
Cold Stratification ◽  
Different Temperatures ◽  
Two Populations

Abstract. Ribeiro KAF, Madeira de Medeiros C, Agudo JAS, Sánchez JS. 2019. Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species. Biodiversitas 20: xxxx. Strategies to halt the decline of biodiversity include: in-situ and ex-situ conservation, the latter already considered at the global level essential in conservation programs. The results of the germinative responses of Carex lainzii Luceño, E. Rico & T. Romero (Cyperaceae), an endemic Spanish endangered species, are presented in this work, to different trials carried out in the laboratory with seeds harvested in the two known populations of that community. Treatments with and without 0.2% potassium nitrate (KNO3) were tested for four, six and eight months in cold stratification at 5 °C in two germination chambers at different temperatures (22/10 °C and 27/15 °C with a photoperiod of 12/12 hours). The results indicate that there is a large difference in germination rates between the two populations. The use of KNO3 did not increase germination rates in any case, but differences were found between periods of cold stratification, with six months being the most effective. On the other hand, the germination rates of both populations remain low (17.58% and 2%) compared to the obtained rate of seed viability. With this first approach to the understanding of the germination requirements of C. lainzii, it becomes clear that new essays are needed to obtain better results, in order to effectively implement the protection plans of C. lainzii populations.

scholarly journals Global patterns of seed germination after ingestion by mammals

2019 ◽  
Author(s):  
Diego A. Torres ◽  
John H. Castaño ◽  
Jaime A. Carranza-Quiceno
Keyword(s):  
Seed Germination ◽  
Plant Communities ◽  
Seedling Recruitment ◽  
Cumulative Effect ◽  
Future Research ◽  
Mammal Species ◽  
Plant Family ◽  
The World ◽  
Germination Success ◽  
Global Patterns

AbstractSeed germination is the first step in seedling recruitment. Understanding what factors determine germination success allows some predictions of the effect of climate change or defaunation on the dynamics of plant communities. Mammals play an important role on seed germination through the ingestion of fruit and seeds. However, the populations of many mammal species have been reduced throughout the world, affecting in many ways the dynamics of plant communities. To understand how the loss of mammal populations might impact the dynamics of plant communities first requires us to collect and synthetize all the available evidence on the effects of mammals on seedling recruitment. Here, we used meta-analytical methods to describe the global patterns of the ingestion of seeds by mammals and their effect on seed germination. Our results showed a positive cumulative effect of mammals on seed germination. However, this effect was not the same for all the mammal orders; it varied depending on the plant family and the bioregion. Additionally, increased seed germination was related to rapid germination. These data highlight the important role that some mammals such as Primates and Elephants have on seed germination, and this poses many questions about the mechanisms behind seed germination patterns that will help to guide future research efforts.

scholarly journals Factors Affecting Germination and Establishment Success of an Endemic Cactus of the Chihuahuan Desert

2021 ◽  
Author(s):  
Eder Ortiz Martínez ◽  
Jordan Golubov ◽  
Maria C. Mandujano ◽  
Gabriel Arroyo Cosultchi
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Chihuahuan Desert ◽  
Seedling Survival ◽  
Life Cycles ◽  
Exclusion Experiment ◽  
Factors Affecting ◽  
Nurse Plants ◽  
Predator Exclusion

Abstract Seeds and seedlings are the most critical stages of cacti life cycles. From the thousands of seeds produced in a reproductive season, only a small fraction successfully germinate, the rest are lost to predation, go dormant and remain viable in the seed bank or lose viability. These early stages often depend on facilitation by nurse plants for germination and seedling recruitment. We aim to prescribe actions for the conservation of Cephalocereus polylophus by improving recruitment in the population. The viability of seeds with different storage times was evaluated as an indicator of their potential to form a short-term seed bank. Through the analysis of seed germination and seedling survival under the canopy of two nurse plant species and open areas, we assessed the importance of facilitation for recruitment. A predator exclusion experiment evaluated the intensity of herbivory on seeds and seedlings of different ages. Seeds had germination rates above 90\% under laboratory conditions, even after two years of storage. Seed germination was only registered under one of the two nurses and after two years, up to 4 % of the seedlings planted under both nurse plants survived and protection against herbivores increased seedlings survival. Considering that facilitation and age are crucial for seedling survival of C. polylophus, future conservation programs should include the protection of plant communities and the introduction of seedlings instead of seeds.

scholarly journals Restoration of Citropsis articulata, a Species at Risk from Medicinal Overharvesting in a Ugandan Rainforest Reserve

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
William Olupot
Keyword(s):  
At Risk ◽  
Seed Germination ◽  
Success Rate ◽  
Species At Risk ◽  
Forest Reserve ◽  
Ongoing Effort ◽  
Germination Success ◽  
Forest Plants

Citropsis articulata, the African cherry orange, is considered to be threatened in Ugandan forests as a result of its purported aphrodisiac properties. This study, part of an ongoing effort to address restoration needs of Mabira Central Forest Reserve in Uganda, demonstrates the feasibility of restoring depleted C. articulata populations using seedlings transplanted from nursery-grown seeds. Phenology of 20 Mabira forest plants was monitored with the aim of collecting seeds. One hundred and fifty-six ripe fruits were collected, and 233 of the extracted seeds were planted in pots in a nursery during January–March 2019. During November-December 2019, seedlings were planted near the sites from which fruits were collected. Seed germination success rate was 89%, and fifteen months after transplanting, in situ survival was 100%. These results suggest that depleted C. articulata populations may be restored in situ using nursery-grown seeds.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

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