Passage:
In coastal ecosystem restoration, seagrass beds (*Zostera marina*) are frequently replanted to mitigate shoreline erosion and sequester blue carbon. Standard restoration protocols historically prioritized high-density planting of mature shoots in sheltered estuaries, operating under the premise that immediate canopy cover provides essential resistance against wave action. However, longitudinal studies reveal that high-density plots in sheltered zones frequently experience localized nutrient exhaustion within three years, leading to sudden canopy die-offs.
Conversely, sparse plantings in moderately exposed coastal zones—historically considered too unstable for sapling survival—exhibit significantly higher long-term root biomass accumulation. Researchers attribute this paradox to fluid dynamics: low-frequency wave movement stimulates the secretion of rooting hormones, prompting deeper rhizome anchoring systems that tap into sub-surface nutrient reservoirs unavailable to shallow-rooted sheltered vegetation. Furthermore, whereas sheltered beds rely predominantly on vegetative cloning, exposed beds demonstrate elevated rates of sexual reproduction and seed dispersal, fostering higher genetic diversity across generations.
Consequently, marine conservationists increasingly favor 'dynamic disturbance planting,' a strategy that deliberately subjects restored beds to moderate hydro-dynamic stress. Although dynamic disturbance planting incurs higher mortality rates during the initial growing season, the surviving meadows exhibit double the climate resilience of traditional sheltered beds during acute marine heatwaves.
Based on the passage, which of the following can be inferred regarding seagrass beds established using traditional restoration protocols?
- AThey fail to sequester blue carbon effectively because vegetative cloning reduces the carbon-absorption capacity of individual seagrass shoots.
- BThey suffer higher sapling mortality during their initial growing season than beds planted using dynamic disturbance techniques.
- Their vulnerability to nutrient exhaustion is due in part to the absence of wave-induced stress that triggers deeper root penetration into sub-surface soil layers.Cevap
- DThey develop deep rhizome anchoring networks over three years that eventually consume all surrounding surface-level nutrients.
- EThey are completely incapable of surviving marine heatwaves because of their total reliance on asexual cloning.