Seed banks can help to maintain the diversity of interacting phytoplankton species

This paper describes a newly developed combined water temperature-ecological (WT-ECO) model which is employed to simulate the effects of global warming on lake and reservoir ecosystems. The WT model includes (i) variations in the eddy diffusion coefficient based on the degree of thermal stratification and the velocity of wind, and (ii) a sub-model for simulating the freezing and thawing processes of surface water, water temperatures, and the mixing rates between two adjacent layers of water. The ECO model then uses these results to calculate the resultant effect on a lake's ecological dynamics, e.g., composition of phytoplankton species, their respective concentrations, and nutrient concentrations. When the model was benchmarked against Lake Yunoko, a dimictic lake, fairly good agreement was obtained over a 4-yr period; thereby indicating it is suitably calibrated. In addition, to assess the effects of global warming on a lake ecosystem, changes in Lake Yunoko's water temperature/quality were simulated in response to an increase in air temperature of 2 - 4°C. Results indicate that such an increase will (i) increase thermal stratification in summer, which increases the nutrient concentrations in bottom water due to nutrient release from bottom sediment, (ii) increase the concentration of phytoplankton at the beginning of the autumn circulation period, and (iii) change the composition of phytoplankton species.

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The Influence of Perenniality and Seed Banks on Polymorphism in Plant-Parasite Interactions

The American Naturalist ◽

10.2307/27735893 ◽

2009 ◽

Vol 174 (6) ◽

pp. 769

Author(s):

Tellier ◽

Brown

Keyword(s):

Seed Banks ◽

Plant Parasite

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Effect of period of sugarcane cultivation on the abundance and distribution of weed seeds in the soil profile

Planta Daninha ◽

10.1590/s0100-83582014000300006 ◽

2014 ◽

Vol 32 (3) ◽

pp. 507-513

Author(s):

R.O. Adereti ◽

F.O Takim ◽

Y.A. Abayomi

Keyword(s):

Land Use ◽

Soil Depth ◽

Seed Banks ◽

Soil Samples ◽

Soil Tillage ◽

Fallow Period ◽

Tillage Practices ◽

Weed Seeds ◽

Seed Distribution ◽

Screen House

An experiment was laid down in a screen house to determine the distribution of weed seeds at different soil depths and periods of cultivation of sugarcane in Ilorin, Nigeria. Soil samples from different depth levels (0-10 cm, 11-20 cm and 21-30 cm) were collected after harvesting of canes from three different land use fields (continuous sugarcane cultivation for > 20 years, continuous sugarcane cultivation for < 10 years after long fallow period and continuous sugarcane cultivation for < 5 years after long fallow period) in November, 2012. One kilogram of the sieved composite soil samples was arranged in the screen house and watered at alternate days. Germinating weed seedlings were identified, counted and then pulled out for the period of 8 months. Land use and soil depth had a highly significant (p £ 0.05) effect on the total number of weeds that emerged from the soil samples. The 010 cm of the soil depth had the highest weed seedlings that emerged. There was an equal weed seed distribution at the 11-20 cm and 21-30 cm depths of the soil. Sugarcane fields which have been continuously cultivated for a long period of time with highly disturbing soil tillage practices tend to have larger seed banks in deeper soil layers (11-20 cm and 21-30 cm) while recently opened fields had significantly larger seed banks at the 0-10 cm soil sampling depth.

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Classification of Post-Fire Responses of Woody Plants to include Pyrophobic Communities

Fire ◽

10.3390/fire3020015 ◽

2020 ◽

Vol 3 (2) ◽

pp. 15 ◽

Cited By ~ 1

Author(s):

Lynda D. Prior ◽

David M. J. S. Bowman

Keyword(s):

Woody Plants ◽

Seed Banks ◽

Classification Systems ◽

Woody Vegetation ◽

General Category ◽

Conifer Species ◽

Soil Seed Banks ◽

Obligate Seeder ◽

In Fire

Developing standardised classification of post-fire responses is essential for globally consistent comparisons of woody vegetation communities. Existing classification systems are based on responses of species growing in fire-prone environments. To accommodate species that occur in rarely burnt environments, we have suggested some important points of clarification to earlier schemes categorizing post-fire responses. We have illustrated this approach using several Australasian conifer species as examples of pyrophobic species. In particular, we suggest using the term “obligate seeder” for the general category of plants that rely on seed to reproduce, and qualifying this to “post-fire obligate seeder” for the narrower category of species with populations that recover from canopy fire only by seeding; the species are typically fire-cued, with large aerial or soil seed banks that germinate profusely following a fire, and grow and reproduce rapidly in order to renew the seed bank before the next fire.

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Effect of different treatments on the seed bank of grazed and ungrazed Baltic seashore meadows

Canadian Journal of Botany ◽

10.1139/b98-102 ◽

1998 ◽

Vol 76 (7) ◽

pp. 1188-1197 ◽

Cited By ~ 2

Author(s):

Heli M. Jutila b. Erkkilä

Keyword(s):

Seed Bank ◽

Brackish Water ◽

Salt Water ◽

Tap Water ◽

Cold Treatment ◽

Abundant Species ◽

Seed Banks ◽

The West ◽

Pesticide Treatment ◽

Juncus Gerardii

Seed banks of two seashore meadows were studied on the west coast of Finland (latitude 61°30'-61°33'N, longitude 21°28'-21°41'E). Samples were taken in June to a depth of 10 cm in the geolittoral zone of the grazed and ungrazed transects. The grazed samples were halved lengthwise: one half was grown immediately, the other after cold treatment. One third of the all samples was treated as controls, one third was watered with brackish water, and one third was given a pesticide treatment. Altogether, 13 926 seedlings germinated and 25 species were identified (three annuals, two biennials, and the rest perennials). Most seedlings were perennial monocots, with Juncus gerardii Loisel. the most abundant species. The seed bank was significantly larger and richer in the ungrazed site than in the grazed site. Cold treatment reduced the number of germinating species and seedlings. In the grazed and non-cold-treated samples, the numbers of species and seedlings were highest in the pesticide treatment. In ungrazed samples there were no significant differences among treatments. After the cold treatment, the least number of species and seedlings was produced by the salt-water treatment. Changing brackish water to tap water led to a burst of germination, especially of J. gerardii. The seed bank of the upper geolittoral zone was richer than that of the middle geolittoral. The multivariate classification and ordination groupings are based on the abundances of J. gerardii and Glaux maritima L.; different treatments were not distinguishable. There was a low resemblance between the seed bank and the aboveground vegetation.Key words: seed bank, salinity, pesticide, seashore meadow, cold treatment, vegetation.

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