Papers by Fallon Tanentzap
Heavy metals influence plant traits that are relevant to its internal water status. Therefore, kn... more Heavy metals influence plant traits that are relevant to its internal water status. Therefore, knowledge of metal effects on a plant's ability to tolerate other stresses such as drought is important to ensure sustainability of restoration efforts in contaminated landscapes, often prone to drought. The aim of this thesis was to gain understanding how heavy metal contamination influences plant-water relationships and how this interacts with effects of a simultaneous drought. Levels ranging from organs to ecosystem processes were investigated. Chapter 1 briefly reviews published studies on interactions between metal and drought stress and highlights potential gaps in literature. Chapter 2 presents results of a 2-year outdoor lysimeter study on the effects of Cu-Ni toxicity on plant-water relationships using saplings of Acer rubrum, Betula papyrifera, and Quercus rubra. The study shows that under elevated metal levels the plants use less water but suffer drought symptoms even if there is water available. Chapter 3 investigates, using B. papyrifera, whether such metal effects on water use are a result of short-term exposure of roots on their water uptake capacity, or due to long-term structural damage e.g. on hydraulic architecture. Both effects were found, but were smaller than hypothesized. In Chapter 4 influence of metals on plant's vulnerability to xylem embolisms in Acer rubrum saplings is found to be higher in the metal contaminated region of Sudbury, Ontario, compared to surrounding uncontaminated regions. Chapter 5 establishes guidelines and limitations for transporting leaves from field to laboratory when measuring leaf relative water content, a method that is important for studying plant water relations in the field. Finally, I conclude with a general overall summary of results and proposed suggestions for reclamation projects.
Paste ..., 2023
The need for projects to focus on permitting and environmental, social and governance (ESG) consi... more The need for projects to focus on permitting and environmental, social and governance (ESG) considerations is increasingly prioritised over the technical and economic aspects of backfill and tailings solutions. This includes not only environmental permitting, but also takes into account public perception and responses to a project, as well as local community engagement and support. To optimise the success of a project, it is essential to incorporate and understand both the mining companies' ESG frameworks and the local and governmental permitting requirements from the beginning. There is a need to pull these more advanced backfill and tailings designs earlier into the process to satisfy permitting requirements rather than the usual execution schedule. Permitting timelines may also lead to temporary backfill solutions such as cemented rockfill until paste backfill can be permitted and implemented. Comparing surface versus underground permitting requirements can lead to a more strategic approach by evaluating alternative solutions for infrastructure placement. For example, some facilities can be located underground if surface is perceived to be contentious. This can also lead to an approach where facility placement that might be better suited underground, but a more conservative approach is to start on surface and move underground as the project progresses. Given the focus on ESG and permitting and the timelines involved, it is more important than ever to provide a narrative which conveys a responsible integrated tailings solution for mining projects, both for permitting and to ensure public support.
Heavy metals influence plant traits that are relevant to its internal water status. Therefore, kn... more Heavy metals influence plant traits that are relevant to its internal water status. Therefore, knowledge of metal effects on a plant's ability to tolerate other stresses such as drought is important to ensure sustainability of restoration efforts in contaminated landscapes, often prone to drought. The aim of this thesis was to gain understanding how heavy metal contamination influences plant-water relationships and how this interacts with effects of a simultaneous drought. Levels ranging from organs to ecosystem processes were investigated. Chapter 1 briefly reviews published studies on interactions between metal and drought stress and highlights potential gaps in literature. Chapter 2 presents results of a 2-year outdoor lysimeter study on the effects of Cu-Ni toxicity on plant-water relationships using saplings of Acer rubrum, Betula papyrifera, and Quercus rubra. The study shows that under elevated metal levels the plants use less water but suffer drought symptoms even if there is water available. Chapter 3 investigates, using B. papyrifera, whether such metal effects on water use are a result of short-term exposure of roots on their water uptake capacity, or due to long-term structural damage e.g. on hydraulic architecture. Both effects were found, but were smaller than hypothesized. In Chapter 4 influence of metals on plant's vulnerability to xylem embolisms in Acer rubrum saplings is found to be higher in the metal contaminated region of Sudbury, Ontario, compared to surrounding uncontaminated regions. Chapter 5 establishes guidelines and limitations for transporting leaves from field to laboratory when measuring leaf relative water content, a method that is important for studying plant water relations in the field. Finally, I conclude with a general overall summary of results and proposed suggestions for reclamation projects.
Environmental and Experimental Botany, 2015
The effects of smelter-damaged environment on embolism resistance in red maple (Acer rubrum L.) w... more The effects of smelter-damaged environment on embolism resistance in red maple (Acer rubrum L.) were investigated with stems of saplings collected in situ from within either the metal-contaminated (mainly Cu and Ni) region of Sudbury, Ontario, or from within the uncontaminated surrounding regions. Current levels of aerial pollution in all regions are low. Hydraulic conductivity was measured after stems were flushed for 40 min and then being spun using the centrifuge technique at −3 MPa. Red maple saplings from within the metal contaminated region had about twice the percent loss of conductivity, due to embolisms, as saplings from outside the contaminated region. Sapling vulnerability to embolism shows contrasting trends with age in contaminated and non-contaminated regions. The increased vulnerability of trees to catastrophic xylem dysfunction under drought may contribute to the observed stunted growth and periodic stem-dieback of trees in metal-contaminated landscapes, the effects being exacerbated by the thin soils.
Botany, 2015
Relative water content (RWC) is widely used to describe plant water status, and is commonly measu... more Relative water content (RWC) is widely used to describe plant water status, and is commonly measured gravimetrically. The ephemeral nature of leaf fresh mass poses severe constraints for such measurements in field-grown plants. These constraints can be overcome by transporting the leaves in waterproof containers into the lab. However, even then, leaves lose water, and other changes may happen. The effects of a delay on the measurement of RWC have not been quantified so far. In this study, the influence of duration of storage up to 96 h and storage temperature on RWC and its components was investigated for four species. Alnus incana subsp. rugosa (Du Roi) R.T. Clausen, Impatiens capensis Meerb., and Scirpus microcarpus J.Presl & C.Presl leaves were stored in plastic bags, whereas those of Comptonia peregrina (L.) J.M.Coult. were stored in plastic vials. RWC remained within 5% of the initial value during 24 h cool storage, but after that, larger changes were observed. The effects of s...
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Papers by Fallon Tanentzap