Secondary Consumer In The Desert

Life on the Food Chain

Have you ever wondered why we can't seem to feed the world's hungry? It'southward a circuitous issue, but information technology might surprise you to learn that it'southward non because there isn't plenty nutrient; current agricultural chapters, based on current technology, exists to feed equally many as 10 billion people. The Earth's population is "only" almost 7 billion. The big question really is: If we want to feed anybody, what would anybody need to eat? To reply that question, download this excel spreadsheet and try plugging in some numbers.

Instance: Ane acre of a grain crop could be used to feed cattle, then the cattle could be used to feed people. If 50% of the energy is lost to the cattle, you could feed twice as many people if you fed them the grain directly. Another way of looking at it is that it would only take a half acre of country to feed the people grain, but a whole acre if y'all feed the grain to the cattle and the cattle to the people. A mutual exercise to abound cattle faster is to feed them footing up creature protein. This means that when nosotros eat the meat from the cow, nosotros're at the tertiary level or higher. The loss of energy between trophic levels may also exist even higher. Recent studies suggest that but ~10% of energy is converted to biomass from one trophic level to the adjacent!

The Food Chain: The respond has to do with trophic levels. Every bit you probably know, the organisms at the base of the food concatenation are photosynthetic; plants on land and phytoplankton (algae) in the oceans. These organisms are called the producers, and they get their free energy directly from sunlight and inorganic nutrients. The organisms that eat the producers are the primary consumers. They tend to be small in size and there are many of them. The primary consumers are herbivores (vegetarians). The organisms that eat the master consumers are meat eaters (carnivores) and are called the secondary consumers. The secondary consumers tend to exist larger and fewer in number. This continues on, all the way up to the superlative of the nutrient chain. About 50% of the energy (perchance as much as 90%) in food is lost at each trophic level when an organism is eaten, so information technology is less efficient to be a higher guild consumer than a main consumer. Therefore, the free energy transfer from one trophic level to the next, up the food chain, is like a pyramid; wider at the base and narrower at the top. Because of this inefficiency, there is only enough food for a few top level consumers, but there is lots of nutrient for herbivores lower downwards on the food chain. There are fewer consumers than producers.

Land and aquatic energy pyramids

Trophic Level	Desert Biome	Grassland Biome	Swimming Biome	Bounding main Biome
Producer (Photosynthetic)	Cactus	Grass	Algae	Phytoplankton
Primary Consumer (Plant eater)	Butterfly	Grasshopper	Insect Larva	Zooplankton
Secondary Consumer (Carnivore)	Lizard	Mouse	Minnow	Fish
Tertiary Consumer (Carnivore)	Ophidian	Ophidian	Frog	Seal
Fourth Consumer (Carnivore)	Roadrunner	Militarist	Raccoon	Shark

Food Spider web: At each trophic level, in that location may be many more species than indicated in the table above. Food webs can be very circuitous. Nutrient availability may vary seasonally or by fourth dimension of day. An organism like a mouse might play ii roles, eating insects on occasion (making it a secondary consumer), but likewise dining directly on plants (making it a primary consumer). A food web of who eats who in the southwest American desert biome might look something like this:

food web

paradigm source: http://iqa.evergreenps.org/science/biology/ecosystem_files/food-spider web.jpg

Keystone Species: In some food webs, at that place is one disquisitional "keystone species" upon which the entire organisation depends. In the same style that an curvation collapses when the keystone is removed, an entire food chain tin collapse if there is a decline in a keystone species. Ofttimes, the keystone species is a predator that keeps the herbivores in bank check, and prevents them from overconsuming the plants, leading to a massive dice off. When nosotros remove top predators like grizzly bears, orca whales, or wolves, for instance, in that location is prove that it affects not just the prey species, but even the physical environs.

Apex Predators: These species are at the height of the food chain and the healthy adults have no natural predators. The immature and old may in some cases be preyed upon, only they typically succumb to affliction, hunger, the effects of crumbling, or some combination of them. The also endure from competition with humans, who often eliminate the acme predators in order to have exclusive access to the prey species, or through habitat destruction, which is an indirect course of competition.

Decomposers: When organisms dice, they are sometimes eaten past scavengers but the remaining tissues are broken down past fungi and bacteria. In this way, the nutrients that were part of the body are returned to the bottom of the trophic pyramid.

Bioaccumulation: In addition to being less energy efficient, eating higher upwardly the food chain has its risks. Pesticides and heavy metals like mercury, arsenic, and lead tend to exist consumed in modest quantities past the main consumers. These toxins get stored in the fats of the animate being. When this fauna is eaten past a secondary consumer, these toxins go more concentrated because secondary consumers consume lots of primary consumers, and ofttimes live longer too. Swordfish and tuna are nigh the summit of the aquatic food chain and, when nosotros eat them, we are consuming all of the toxins that they have accumulated over a lifetime. For this reason, pregnant women are brash confronting eating these foods.

Solve the following problems mathematically.

1. Given: 10 billion people can be fed a basic vegetarian nutrition that is nutritionally complete. How many people could we feed at the American standard-a tertiary level of consumption (3rd club consumers?). fifty% of the energy is lost by each higher level.

ii. If there are 250 million people in the United States virtually of them eating at the 3rd (3rd) level of consumption, how many people could we feed at the Chief level?

3. Some animals similar sharks are fifth order consumers! Sharks eat tuna that eat mackerel that consume herring that eat copepods that consume diatoms. If nosotros were to make the reasonable assumption that each of these animals eats ii of its casualty each 24-hour interval, how many organisms died to feed the shark in one solar day?