Abstract Detail



Ecophysiology

Elkin, Lucy [1], Kilgore, Jason [2].

Physiology and growth of little bluestem (Schizachyrium scoparium) on abandoned coal mine waste.

Abandoned coal mine waste has low nutrients and high heavy metal content, thus limiting plant colonization. Characterizing plant responses in these environments can inform improved reclamation practices. This study aimed to (1) understand the physiology of the C4 grass little bluestem (Schizachyrium scoparium) already growing on coal mine waste and (2) experimentally determine the combination of plant species and soil amendments that best promotes revegetation of mine waste. Chlorophyll content, plant height, and photosynthetic parameters associated with instantaneous responses to varying carbon dioxide (CO2) and light levels were measured across two types of waste sites – oxidized and unoxidized – and one reclaimed site early and late in the little bluestem growing season. Vegetative stalk height was higher in June than August for the unoxidized site (p=0.009), and chlorophyll content was greater in June than August at the oxidized site (p=0.037), but there were no significant differences across sites. For all sites, Phi was higher in August (p=0.002), while Θ was lower in August across all sites (p=0.016), suggesting higher photosynthetic efficiency in August. Additionally, the light saturating level for photosynthesis (Qsat) was higher in the reclaimed site than the waste sites in June (p<0.001), while Θ was lower in the reclaimed site for June (p<0.001). Thus, photosynthetic efficiency at mid-light levels was higher in the little bluestem plants on the reclaimed site compared to the waste sites. There was no difference in Vcmaxbetween sites or across sites between seasons (p>0.064). On the other hand, plants at the reclaimed site had a higher photosynthetic electron transport rate (Jmax) compared to the two waste sites in July (p<0.002). Overall, we found little evidence that little bluestem is negatively affected by the mine waste since there was a lack of differences across sites. In addition, in Fall 2018, we established an experimental planting with combinations of plants (little bluestem, annual rye (Lolium multiflorum), strip mine seed mix, or lavender (Lavandula angustifolia andL. grosso) and soil amendments (lime, straw, mycorrhizal fungi, all, or none) on unoxidized coal mine waste. Annual rye was the only species that had germinated, regardless of soil treatment. There was no detected difference in germination across treatments (p>0.175), although lime provided the best results with the highest mean germination. Overall, little bluestem is not substantially impacted by the negative environmental conditions associated with coal mine waste, and annual rye germinates very efficiently, especially in plots treated with lime.


1 - Washington and Jefferson College, Biology, 50 South Lincoln St Box520, Washington , PA, 15301, USA
2 - Washington & Jefferson College, Biology, 60 South Lincoln Street, Washington, PA, 15301, United States

Keywords:
Schizachyrium scoparium
Physiology
coal mining
reclamation
revegetation.

Presentation Type: Oral Paper
Number: 0008
Abstract ID:247
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation


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