scholarly journals Contribution to the characteristic of Cladium mariscus (L.) Pohl population in the initial zone of floating mat on an oligo-humotrophic lake in north-eastern Poland

2011 ◽  
Vol 74 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Anna Namura-Ochalska
Keyword(s):  
Open Water ◽  
Natural Conditions ◽  
Hard Seed ◽  
Rhizome Growth ◽  
North Eastern ◽  
Mother Plants ◽  
Initial Zone ◽  
Seed Coats ◽  
Natural Barrier ◽  
Floating Mat

In the initial phase of growth in an oligo-humotrophic lake, <em>Cladium mariscus</em> forms a dense and tall sawgrass bed invading the open water in the form of a floating mat. High densities of submerged evergreen perennial stems of <em>C. mariscus</em>, over two metres high and abundantly fruiting, ensure its persistence, and form a natural barrier to the invasion of other species. Dense mats of sawgrass are formed as a result of clonal and rhizome growth. Although diaspore production is abundant under natural conditions, only vegetative propagation of stems was observed. In different variants of the experiment only seeds wintering on stems of mother plants were capable of germinating. Hard seed coats had an important effect on the germination capacity of seeds.

Some physical and chemical features of two upland crater lakes in tropical north-eastern Australia

1999 ◽  
Vol 50 (2) ◽  
pp. 159 ◽  
Author(s):  
D. Walker
Keyword(s):  
Thermal Stability ◽  
Meteorological Data ◽  
Euphotic Zone ◽  
Open Water ◽  
Crater Lakes ◽  
Ground Temperatures ◽  
Eastern Australia ◽  
North Eastern ◽  
Physical And Chemical ◽  
Continuous Deposition

Lakes Barrine and Eacham, ~1.0 and 0.5 km2 area, 67 and 63 m depth respectively, lie at ~740 m a.s.l., ~17°S in north-eastern Australia. Seasonal changes in their volumes modelled from meteorological data correspond well with observations at Eacham. Temperature profiles through 6 years show summer stratification with a metalimnion at 20–30 m; in winter, near isothermy is usually attained. At Barrine, thermal stability varies between winter and summer (<500 and >4000 g-cm cm-2 respectively). Mixing is related to low ground temperatures during periods of generally low thermal stability; exceptionally it penetrates to >60 m. Oxygen saturation decreases from the surface to ~20% at the base of the euphotic zone (15–21 m) but oxygen is carried lower by mixing after which anoxia commonly rises to ~40 m. At Barrine, Fe-reducing redox (<200 mV) usually occurs below 50 m, but during mixing this boundary falls to within 1 m of the mud–water interface. The Barrine solution is dilute (total dissolved solids 55–58 mg L-1), and that of Eacham is more so. A concentrated monimolimnion has developed in the lowermost 2–3 m at Barrine but not at Eacham. Sedimentation at the middle of each lake results from the continuous deposition of open-water products punctuated by the redistribution of coarser detritus from the ‘shallows’ at times of deep mixing. The resultant laminations are preserved only at Barrine, protected by the chemical stability of the monimolimnion.

scholarly journals A PHYSIOLOGICAL APPROACH TO CONSERVATION OF FOUR PALM SPECIES: ARENGA AUSTRALASICA, CALAMUS AUSTRALIS, HYDRI- ASTELE WENDLANDIANA AND LICUALA RAMSAYI

REINWARDTIA ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 237
Author(s):  
Dian Latifah ◽  
Robert A. Congdon ◽  
Joseph A. Holtum
Keyword(s):  
Economic Value ◽  
Red Light ◽  
Tropical Rainforests ◽  
Light Conditions ◽  
Marginal Lands ◽  
Hard Seed ◽  
Palm Species ◽  
Physiological Approach ◽  
Physical Treatments ◽  
Seed Coats

Palms (Arecaceae) are an important component of many tropical rainforests. Many have also been cultivated widely for agricultural commodities with high economic value. They are also important components in rehabilitation of disturbed or marginal lands. Knowledge and application of germination strategies are essential in the cultivation of palms. Many species have seeds that do not germinate readily, even when light conditions are favourable. This research determined the effects of seed coats, light and temperature on germination of Arenga australasica (H. Wendl. & Drude) S. T. Blake ex H. E. Moore, Calamus australis Mart., Hydriastele wendlandiana (F. Muell.) H. Wendl. & Drude and Licuala ramsayi var. tuckeri Barford & Dowe. We examined physical treatments to promote germination or break dormancy, as well as different light and temperature conditions. The results showed that the hard seed coats of the four species slowed imbibition. Scarified seeds germinated best for A. australasica, C. australis and L. ramsayi. The germination of all seeds was inhibited by far red light. The red light requirement suggests that these species prefer to colonise open areas. This implies that dispersal agents, canopy gaps and forest margins may play important roles in promoting regeneration as well as conservation of these palm species.

scholarly journals Effect of Organic and Botanicals Priming on Seed Quality Parameter of Pigeonpea (Cajanuscajan (L.) Millspaugh)

2021 ◽  
pp. 1-5
Author(s):  
A. Divij Reddy ◽  
A. K. Chaurasia ◽  
P. K. Shukla ◽  
Ram Pal Singh
Keyword(s):  
Growth Regulators ◽  
Leaf Extract ◽  
Seed Quality ◽  
Quality Parameters ◽  
Quality Parameter ◽  
The Other ◽  
Hard Seed ◽  
Normal Seedling ◽  
Seed Coats ◽  
Moringa Leaf Extract

Presence of hard seed coats and several seed borne pathogens hinder the normal seedling establishment in legumes. Earlier seed enhancement is mainly achieved though synthetics and growth regulators. To evaluate the effect of organics and botanicals on quality parameters of the seed an experiment was conducted in Sam Higginbottom University of Agriculture, Technology and Sciences. Treatments in the experiment comprised of Panchagavya at 3%, 5% and 7% for 12 hrs., Beejamrutha at 5%, 7% and 9% for 12 hrs., Coconut water at 6% and 8% for 12hrs., Moringa leaf extract at 5% and 7% for 12hrs and Sea weed extract at 3% and 5% for 12hrs.Priming with the selected organics and botanicalsis found to enhance the quality parameters compared to untreated control. The treatment Panchagavya at 7% for duration of 12 hours was found to be superior compared to the other treatments in the study.

Mechanical Scarification of Dodder Seeds with a Handheld Rotary Tool

2012 ◽  
Vol 26 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Katherine M. Ghantous ◽  
Hilary A. Sandler
Keyword(s):  
Seed Weight ◽  
Field Research ◽  
Batch Size ◽  
Research Projects ◽  
Hard Seed ◽  
Rotary Tool ◽  
Reliable Methods ◽  
Seed Coats ◽  
Grinding Stone ◽  
Germinated Seeds

Dodder seeds are physically dormant because of hard seed coats and do not readily germinate without scarification. Reliable methods of scarification for small lots of dodder seed are needed to facilitate laboratory, greenhouse, and field research projects. Dodder seed was scarified for varying times using a handheld rotary tool at the 10,000 rpm setting with a conical grinding-stone bit attached. Percentage of germination and weight change of seeds were assessed using scarification times between 0 and 4 min at 0.5-min increments. Mean seed weight loss and mean number of germinated seeds increased quadratically as scarification time increased. Scarifying for 2.5 min was judged the shortest time with maximal germination. Another study evaluated the effect of seed number (100 to 400 seeds sample−1) on the efficacy of rotary tool scarification when scarification time was held constant at 2.5 min. Percentage of germination decreased linearly as seed batch size increased. The handheld rotary tool provides consistent and repeatable scarification of dodder seed with germination rates greater than 80%.

Anatomical structure and nutritive value of lupin seed coats

2001 ◽  
Vol 52 (10) ◽  
pp. 985 ◽  
Author(s):  
Z. H. Miao ◽  
J. A. Fortune ◽  
J. Gallagher
Keyword(s):  
Seed Coat ◽  
Nutritive Value ◽  
Crude Fibre ◽  
Hard Seed ◽  
Anatomical Analysis ◽  
Lupin Seed ◽  
Series Of Experiments ◽  
Selection For ◽  
Growing Conditions ◽  
Seed Coats

Selection and breeding for yield and adaptation to environmental conditions often changes a number of characteristics of crops, and may influence the value of seed for animals. A series of experiments was conducted to evaluate the effect of breeding and growing conditions on the structure and degradability of lupin seed coats. Breeding has had significant influences on both seed size and seed coat structure of lupins. For instance, cultivars of Lupinus angustifolius released in 1987 and 1988 tended to have smaller seeds with a thicker seed coat than those released in 1971 (P < 0.05). Selection for soft seeds has resulted in a reduction of seed coat thickness in L. angustifolius. Hardseeded and roughseeded lines of L. cosentinii had thicker coats (P < 0.05) than softseeded and smoothseeded, respectively. The main contributor to the thick seed coat of hardseeded lines was a layer of cells known as the hourglass layer, which is located between the outer palisade and inner parenchyma. Anatomical analysis revealed that the soft seed coat tended to have short and round cells, whereas the hard seed tended to have long cells in the palisade layer. Smooth seeds had round cells in the subpalisade, but rough seeds had long cells in this layer. Although the seed coats of lupins contained about 80% crude fibre, with L. cosentinii and L. pilosus having more fibre than L. angustifolius, the fibre in lupin seed coats was highly digestible by sheep.

scholarly journals A Review on the environmental and health impacts due to electronic waste disposal in Bangladesh

2021 ◽  
Vol 8 (2) ◽  
pp. 116-125
Author(s):  
Romana Afrose Meem ◽  
Arif Ahmed ◽  
Md. Shamim Hossain ◽  
Ruhul Amin Khan
Keyword(s):  
Electronic Waste ◽  
Open Water ◽  
Health Impact ◽  
North Eastern ◽  
Open Land ◽  
Hazardous Compounds ◽  
Insight Into ◽  
Dust Ingestion ◽  
Land Filling

Bangladesh is one of the main importer countries of e-waste in the world. Moreover, country also generates e-waste about 2.81 million metric tons per year. However, majority of e-waste is being dumped into the open soil, open land, or open water bodies resulting problem on environment (i.e., pollution) and human population (i.e., health). Therefore, present review summarizes the environmental and health impact due to disposal of e-waste. Poorly management of e-waste during the collection, processing, recycling, and land filling causing environmental impact followed by air pollution, soil pollution, water pollution, and degradation of the beach because hazardous compounds spread to the surrounding or environment. Furthermore, e-waste also creates lots of health problems. Humans can be exposed to e-waste contaminants by the inhalation, dietary intake, dust ingestion, and dermic contact. In north eastern part of Bangladesh, about 36.3% women who lives near recycling sites experienced the death of a baby. Again, about 15% child laborers die, and 83% child laborers are affected by long term health problem because of e-waste mismanagement practice. There are about 120,000 Bhangaries who may be exposed to e-waste contaminants more seriously. The result of the study would provide us important insight into the growing concern of e-waste and would help policy maker for designing policy measure to recycle e-waste in a hazard free manner.

Possum extinctions at the marsupial frontier: the status of the northern common cuscus Phalanger orientalis on Santa Ana Island, Makira Province, Solomon Islands.

2002 ◽  
Vol 24 (2) ◽  
pp. 247 ◽  
Author(s):  
TE Heinsohn
Keyword(s):  
Scientific Literature ◽  
Solomon Islands ◽  
Open Water ◽  
Oceanic Islands ◽  
Santa Cruz ◽  
Santa Ana ◽  
The North ◽  
North Eastern ◽  
The Status ◽  
Far Eastern

ON zoogeographic maps, the Solomon Islands are shown as the north-eastern limit of Australidelphian marsupial distribution in Australasia. This distinction is due to the presence of a single New Guinean marsupial, the northern common cuscus Phalanger orientalis, which was probably introduced via the Bismarck Archipelago by prehistoric human agency (Flannery 1995; Spriggs 1997; Heinsohn 1998; Wickler 2001). P. orientalis is found across most of the principal Solomon Islands, with the exception of the remote far-eastern oceanic islands of Santa Cruz (Temotu) Province. In the scientific literature, the exact eastern limit of distribution for P. orientalis is generally given as San Cristobal (Makira) Island in Makira Province (Laurie and Hill 1954; Flannery 1995), the eastern most peninsula of which extends to 162� 23' E. The next landmass to the east is the small 5 km diameter and 143 m high limestone atoll of Santa Ana (Owa Rafa) which lies across a 7.5 km open water crossing.

scholarly journals The crypsis hypothesis explained: a reply to Jayasuriya et al. (2015)

2015 ◽  
Vol 25 (4) ◽  
pp. 402-408 ◽  
Author(s):  
Torbjørn R. Paulsen ◽  
Louise Colville ◽  
Matthew I. Daws ◽  
Sigrunn Eliassen ◽  
Göran Högstedt ◽  
...  
Keyword(s):  
Seed Coat ◽  
Generation Time ◽  
Dormancy Release ◽  
Hard Seed ◽  
Theory Of Evolution ◽  
Key Features ◽  
Evolution By Natural Selection ◽  
Hard Seed Coat ◽  
Seed Coats ◽  
By Products

AbstractIn imbibing seeds, resumption of metabolism leads to the unavoidable release of volatile by-products that are perceived as cues by rodent seed predators. The crypsis hypothesis proposes that the primary function of a water-impermeable, hard seed coat is to reduce rodent seed predation by rendering seeds olfactorily cryptic. In an opinion paper, Jayasuriya et al. (2015) find the crypsis hypothesis unscientific and ‘not consistent with Darwin's theory of evolution by natural selection’. It is unfortunate that Jayasuriya et al. (2015) did not appreciate that the crypsis hypothesis offers an alternative explanation for the evolution of water-impermeable seeds: released seed volatiles are cues used by rodents to locate seeds, and variation in seed-coat permeability leading to differences in seed volatile release represents the variable under selection. Furthermore, the sealing of water-impermeable seed coats imposes a cost of increased generation time and, therefore, dormancy-release mechanisms are expected to subsequently evolve in response to local environmental conditions. We also disagree with most other claims by Jayasuriya et al. (2015), who failed to appreciate how species with dimorphic seeds – one morph with permeable and the other with impermeable seed coats – benefit from rodent caching behaviour and population dynamics. We welcome this opportunity to clarify and elaborate on key features and the evolution of water-impermeable seed coats according to the crypsis hypothesis.

scholarly journals Summer fluxes of methane and carbon dioxide from a pond and floating mat in a continental Canadian peatland

2016 ◽  
Author(s):  
M. Burger ◽  
S. Berger ◽  
I. Spangenberg ◽  
C. Blodau
Keyword(s):  
Carbon Dioxide ◽  
Hot Spot ◽  
Open Water ◽  
Small Scale ◽  
Co2 Uptake ◽  
Bubble Frequency ◽  
Closed Chamber ◽  
Ch4 Emissions ◽  
Carbon Dioxide Co2 ◽  
Floating Mat

Abstract. Ponds smaller than 10000 m2 likely account for about one third of the global lake perimeter. The release of methane (CH4) and carbon dioxide (CO2) from these ponds is often high and significant on the landscape scale. We measured CO2 and CH4 fluxes in a temperate peatland in southern Ontario, Canada, in summer 2014 along a transect from the open water of a small pond (847 m2) towards the surrounding floating mat (5993 m2) and in a peatland reference area. We used a high-frequency closed chamber technique and distinguished between diffusive and ebullitive CH4 fluxes. CH4 fluxes and CH4 bubble frequency increased from a median of 0.14 (0.00 to 0.43) mmol m−2 h−1 and 4 events m−2 h−1 on the open water to a median of 0.80 (0.20 to 14.97) mmol m−2 h−1 and 168 events m−2 h−1 on the floating mat. The mat was a summer hot spot of CH4 emissions. Fluxes were one order of magnitude higher than at an adjacent peatland site. During daytime the pond was a net source of CO2 equivalents to the atmosphere amounting to 0.13 (−0.02 to 1.06) g CO2 equivalents m−2 h−1, whereas the adjacent peatland site acted as a sink of −0.78 (−1.54 to 0.29) g CO2 equivalents m−2 h−1. The photosynthetic CO2 uptake on the floating mat did not counterbalance the high CH4 emissions, which turned the floating mat into a strong net source of 0.21 (−0.11 to 2.12) g CO2 equivalents m−2h−1. This study highlights the large small-scale variability of CH4 fluxes and CH4 bubble frequency at the peatland-pond interface and the importance of the often large ecotone areas surrounding small ponds as a source of greenhouse gases to the atmosphere.

Security Eating, and Diet in the Large Rock-Rat, Zyzomys Woodwardi (Rodentia:Muridae).

1980 ◽  
Vol 7 (1) ◽  
pp. 63 ◽  
Author(s):  
RJ Begg ◽  
CR Dunlop
Keyword(s):  
Northern Territory ◽  
Food Hoarding ◽  
Hard Seed ◽  
Seed Coats

The diet of Zyzomys woodwardi was studied by the identification of seeds eaten and accumulated in crevices at Nangaloar Caves, Northern Territory. Seeds of 11 species of plants of nutritional significance were identified; the most frequent were Canarium australianum, Terminalia carpentariae and Buchanania obovata. It was concluded that the accumulations of seeds did not represent caches or food hoarding but were the results of seeds being carried by rats to secure positions which provided protection from predators while the hard seed coats were gnawed through.

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