... What is a bottom-up cascade? The elimination of apex predators destabilizes ecosystems, setting off chain reactions that eventually cascade down the trophic ladder (or food web) to the lowest rung, often reducing habitat complexity and species diversity. We quantify the economic damages of the degradation of an important ecosystem service, water clarity, caused by invasion by … The idea of a particular area or resource being of local significance or being integral to, or improving the ecology as a whole has become central to my scenario for Tinsley. These may include having the students work through one of the case studies in the Exploring Trophic Cascades Click & Learn to determine if they can correctly apply the concepts to other scenarios, or using a quiz through your learning management system as an assessment. An effect on apex predators caused by a … fishes Humans Otters (1) California Otters (1) Urchins (1) Kelp (3) ALASKA whales (? Fishes (4) Lobster Pred. Which of these scenarios does not describe a trophic cascade? Despite these challenges, trophic cascades have now been documented in all of the world’s major biomes—from the poles to the tropics and in terrestrial, freshwater, and marine systems (table S1). Paine coined the term trophic cascade to describe such multi-level trophic interactions. Although investment in the prevention of species invasions may sustain ecosystem services, these effects of invasions are rarely measured in monetary terms useful to decision makers. The theory which describes the relative importance of nutrients (bottom-up) or species composition (top-down) on ecosystem function has never been tested in detritus-based aquatic systems earlier. After learning about the terms keystone species and trophic cascades I fell in love with ecology a little more (if that is possible). Trophic cascades scenario of a detritus-based stage-structured model in marine ecology. These cascades are an example of how a single entity can improve an ecology as a whole with effects that propagate downward thorough webs across multiple trophic levels. The 1995/1996 reintroduction of gray wolves (Canis lupus) into Yellowstone National Park after a 70 year absence has allowed for studies of tri-trophic cascades involving wolves, elk (Cervus elaphus), and plant species such as aspen (Populus tremuloides), cottonwoods (Populus spp. Trophic level, step in a nutritive series, or food chain, of an ecosystem.The organisms of a chain are classified into these levels on the basis of their feeding behaviour.The first and lowest level contains the producers, green plants.The plants or their products are consumed by the second-level organisms—the herbivores, or plant eaters. Invasive species represent a largely unquantified threat to ecosystem services. These topics are so fascinating to me and I love teaching them to my students. The students will separate the listed elements of the Wyoming ecosystem into these groups and create their own example of a potential trophic cascade in Wyoming. Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. Start studying Labster - Endocrinology, Labster, Labster answers. ), and willows (Salix spp. Trophic Cascades. Learn vocabulary, terms, and more with flashcards, games, and other study tools.