NRE 3105 Lecture Notes - Lecture 13: Invasive Species, Phragmites, Typha
26 Jan 2019
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Document Summary
Invasive species: non-native species that become widely spread and dominant: change wetland structure and function. Introduced deliberately or accidentally: growth-limiting factors are absent, allowing them to flourish (predators, disease, competitors, major ecological and economic effects, one of the biggest threats to biodiversity. Wetlands cover 5% of the land surface, but have 25% of the world"s most invasive plant species. Why: often sinks for nutrients, they accumulate, sediments, water, nutrients, propagules (seeds, rhizomes, salt, debris, disturbed hydroperiods. Sedimentation smothers diverse community, fills in microtopography, and promotes invasive grass: excess nutrient loading shifts marsh plant communities, often promotes invasive like hybrid typha. Mechanisms of invasive plants that reduce biodiversity and increase carbon storage. Chemical: grow tall, cast shade, capture nutrients, produce copious biomass, homogenize habitat, reduce temperature, create recalcitrant litter. Wetlands have carbon rich soils: wetlands only cover ~5% of the global land area, but contain 1/3 of the global soil"s carbon (mostly.
