However, the greater biomass and depth of tree roots may have greater potential for promoting environmental conditions that can improve rhizoremediation, such as increased metabolizable organic carbon, oxygen, and water. Grasses were more heavily represented in the literature and therefore demonstrated a wider range of effectiveness. The objective of this review was to compare the effectiveness of trees and grasses for rhizoremediation of hydrocarbons and address the advantages of each vegetation type.
Trees and grasses are commonly used for phytoremediation, with trees typically being chosen for remediation of BTEX while grasses are more commonly used for remediation of PAHs and total petroleum hydrocarbons. Rhizoremediation of petroleum contaminants is a phytoremediation process that depends on interactions among plants, microbes, and soils.
Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).Ĭomparison of trees and grasses for rhizoremediation of petroleum hydrocarbons. CAM plants transpire during the night and thus perform HR during the day. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. The modeling results show that deep-rooted CAM plants in CAM- grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants.
#Selina dispersio Patch
We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM- grass, and tree-CAM associations at the growing season to yearly timescale. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM- grass, and tree-CAM associations). Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. Modeled hydraulic redistribution in tree-grass, CAM- grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM). The ability to simulate the bistability and transition of trees and grass throughout the tropics is critical to representing vegetation dynamics in response to changing climate and CO2. If trees are able to escape mortality a tree-grass bistable area is successful. Within the forest- grass transition area there is a critical time during which grass fuels fire spread and prevents the establishment of trees. Results for simulation scenarios where vegetation is represented by all trees, all grass, or a combination of competing trees and grass are compared to assess changes in biomass, fire regime and tree-grass coexistence. As a size-structured model, FATES allows for variable mortality based on the size of tree cohorts, where larger trees experience lower morality compared to small trees. Fire occurs within the model with variable intensity that kills trees according to the combined effects of cambial damage and crown scorch due to flame height and fire intensity. FATES-Spitfire tracks fire ignition, spread and impact based on fuel state and combustion. FATES has been updated to use a fire module based on Spitfire.
#Selina dispersio simulator
Utilizing the Functionally Assembled Terrestrial Ecosystem Simulator (FATES), a demographic vegetation model, and the CESM ESM, we explore the coexistence of trees and grass across the tropics with an active fire regime. The cause of this transition and bistability has been linked to the interacting effects of climate, vegetation structure and fire behavior. Tropical forests are characterized by transition zones where dominance shifts between trees and grasses with some areas exhibiting bistability of the two. Coexistence of Trees and Grass: Importance of climate and fire within the tropics
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