Rehabilitation of kimberlite tailings in the afro‐alpine zone of Lesotho: seed germination and plant performance of native grassland species across different topsoil mixtures

In grassland biodiversity experiments the positive biodiversity−ecosystem functioning relationship generally increases over time. However, we know little about the underlying short-term evolutionary processes. Using five plant species selected for twelve years in a biodiversity experiment in mixture or monoculture and plants without such a selection history, we assessed whether differential selection altered productivity, biodiversity effects, and functional trait differences within newly assembled monocultures and 2-species mixtures. Plants without past community selection history produced the lowest assemblage biomass and showed the weakest biodiversity effects. In newly assembled mixtures, plants with a selection history in mixtures produced more biomass than plants with a monoculture selection history. Biodiversity effects were generally positive and differed significantly between selection histories. However, contrary to our expectations, biodiversity effects were not stronger for mixture-type plants. Biodiversity effects were influenced by both trait differences between plants and community-weighted means, but these relationships were mostly independent of selection history. Our findings suggest that twelve years of selection history in monocultures or species mixtures differentiated plants of each species into monoculture-and mixture-types. Such rapid evolution of different community-types within grassland species and its effect on ecosystem services and functioning are likely to be important for species conservation practice.

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INFLUENCE OF LIGNITE-ACTIVATED WATER ON SEED GERMINATION, CUTTING PROPAGATION, AND PLANT PERFORMANCE

HortScience ◽

10.21273/hortsci.31.5.744a ◽

1996 ◽

Vol 31 (5) ◽

pp. 744a-744

Author(s):

Rachel Emrick ◽

D. L. Creech ◽

G. Bickerstaff

Keyword(s):

Seed Germination ◽

Woody Species ◽

Dry Weight ◽

Echinacea Purpurea ◽

Germination Percentage ◽

Plant Performance ◽

Cutting Propagation ◽

Meta Silicate ◽

Rapid City ◽

Sodium Meta Silicate

This project tested rates of lignite-activated water (LAW) for its influence on seed germination, cutting propagation, and plant performance. LAW is a product of CAW Industries, Rapid City, S.D. LAW is water-activated by lignite in a process that includes the addition of sulfated castor oil, calcium chloride, magnesium sulfate, sodium meta silicate, and fossilized organics from refined lignite. LAW is reported to improve many plant performance traits. Four rates were used in this study. Seed germination trials indicated no significant differences in germination percentage with LAW applications with the two species tested, Echinacea purpurea and Hibiscus dasycalyx. In a “closed” system, LAW enhanced cutting propagation success of Aster caroliniana, Cuphea micropetala, and Verbena `Homestead Purple', as measured by percent rooting and dry weight of roots produced. Cutting propagation of two woody species, Illicium henryi and Rosa banksiae, was not improved with LAW additions. In the SFASU Arboretum, pansy performance, as measured by plant dry weight, was improved one month after establishment.

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