Bio Exam 2 Review

How much rain do rainforests get?

At least 80 in. per year, up to 430 in

Give a specific example of how global warming impacting our world.

Bangladesh has lost thousands of acres to sea level rise, causing a huge humanitarian crisis as people lose their lands and farms.

Where are tropical rainforest restricted to in the world?

Between the Tropic of Cancer and the Tropic of Capricorn

It is not just sunshine that makes the tropical rain forest so diverse, but there are other factors such as seasonality. Please explain the research and conclusions discussed in "Seasonality, the latitudinal gradient of diversity, and Eocene insects"

Biotic diversity is higher in areas of plentiful light & heat. Seasonality reduces the amount of species diversity in insects

Most ecologists disagree with the "Top to Bottom" theory as an explanation as to 'Why The World is Green.' Instead some ecologist prefer the "Bottom Up" theory. Explain what theory and the ramifications, and give two specific examples support this theory.

Bottom Up Theory Theory that lower trophic levels limit the trophic level above them. So, primary producers limit herbivores who limit carnivores. This is the most commonly accepted theory. Ex. Plants create defenses to limit herbivores such as structural adaptations like thorns. Ex. Caterpillar destroys crops, plants send out chemicals to attract wasp that kills the caterpillar.

What are two things affecting the water cycle of tropical rainforests?

Deforestation and Climate Change

Drought makes rainforests susceptible to what?

Die-offs of trees, forest fires

How do rainforests create their own rain?

During photosynthesis, plants release water from their leaves through transpiration. This water is then absorbed into the sky and then forms clouds and therefore rain.

What is the difference between fundamental and realized niche?

Fundamental niche - entire niche that a species capable of using, based on physiological tolerance limits and resource needs Realized niche - actual set of environmental conditions, presence or absence of other species, in which the species can establish a stable population Other causes of niche restriction - predator absence or presence, absence of pollinators, presence of herbivores

Back in 1960, Hairston, Smith and Slobodkin proposed the 'Green World Hypothesis', however, it was not until 2006 that John Terborgh and researchers were able to test this hypothesis. State what the "Green World hypothesis" states and the ramifications of this.

Hypothesis: islands without predators will have a decline in plant production. -Researchers looked at individual island-like sites near a reservoir. Small islands had no predators, medium islands had no vertebrate predators, and large islands had vertebrate predators. They looked at relationships and plants being eaten. Results: islands with no predators had huge proportion of stems being eaten and almost no plants left because herbivores weren't kept in check. In the islands with predators, the predators kept herbivores in check, and plants remained populated. Conclusion : The data supported the Green World Hypothesis, meaning top-down works. Predators are necessary to keep herbivores in check who then keep plants in check.

The world is a competitive place, and if you can avoid putting energy into competing for a needed resource you might win out. Discuss one species that lives in Madagascar and how they avoid direct completion. Explain why resource partitioning is important in evolution and give an example

In the rainforests of Madagascar, the greater bamboo lemur and the golden bamboo lemur are much more selective in choosing which species of bamboo they will feed on, and this certainly accounts for their extremely limited distribution. Both species prefer feeding on Madagascar's endemic giant bamboo which is not at all common. However, to avoid feeding competition when occupying the same forest, which these two species sometimes do, each lemur feeds on a different part of the giant bamboo. The golden bamboo lemur prefers leaf petioles and new shoots, while the greater bamboo lemur is highly selective towards the tender inner pith, and will literally shred the toughest and most mature stalks to get access to the tasty pith within. Only the golden bamboo lemur can eat the shoots because it is immune to the concentration of cyanide that it has. Due to the low energy content in the bamboo, abundance of bamboo, and lack of competition, little energy expenditure is required

Above is a biomass pyramid. Please draw an inverted pyramid. What is a good example of an inverted pyramid?

Inverted biomass pyramids represent food chains that require relatively low weight producers to support heavy apex predators that have a lot of biomass.

Why are the brown leaf chameleon important to the ecosystem?

It camouflages to look like a dead leaf and it also has horns. It uses its camouflage to hide from predators and to hunt prey. It is also endangered.

What niche do the tenrecs occupy and why are they important?

It eats worms, which its teeth are specialized for. Semi-aquatic which is kinda cool. It's threatened and it is the only one of its genus -- if they disappear we lose it

Explain John Terborgh et al research testing this hypothesis. - What was he testing? Do not say Green World Hypothesis- explain it.

John Terborgh was testing whether herbivore populations are kept in check by plant defenses or through predation.

Please explain the equation NPP = GPP - R , and why this is important to ecosystems

Net Primary Production= Gross Primary Production (amount of C02 fixed by plants in photosynthesis) - costs of plant respiration (CO2 lost): Almost all life on earth is directly or indirectly reliant on primary production

How has predation influenced the evolution of animals and plants? Please give 4 specific examples.

Plants and animals that can stay alive longer and disguise themselves from predators have a better chance to survive and pass on their genes. Over time, this leads to adaptations for defense mechanisms that allow for species to hide from their predators. The predators kill the prey that is more easily found. Examples: 1. Grasshoppers looking like a part of a leaf 2. Flat tailed horned lizard which has evolved to camouflage and not give off a shadow 3. Poison dart frogs that aren't actually poisonous but look poisonous because they look like other species 4. Butterflies that evolved to look like monarchs but aren't-Viceroy

Recently researchers, Dr. Grosberg and Vermeij, have proposed an interesting trigger for this diversification. Please explain their discovery and how this relates to NPP of an ecosystem, and how it explains the biodiversity of landlubbers.

Researchers found that veins on leaves increased, so this allowed more photosynthesis and therefore more energy. As a result, bigger animals could develop to live off plants that supplied greater energy and greater NPP

What ecosystem service do the rainforests serve our world?

Storing hundreds of billions of tons of carbon Buffering against flood and drought Stabilizing soils Influencing rainfall patterns Providing a home to wildlife and indigenous people Rainforests are also the source of many useful products upon which local communities depend.

What is the 6th mass extinction? What is the difference between mass extinction and background extinction?

The 6th mass extinction is currently on going and is the result of human's impact on the environment through the destruction of ecosystems and committing land to development. Thousands of species are going extinct every year, and this trend does not seem to be slowing down. The difference between mass extinction and background extinction is the rate of species that are going extinct, with an unusually high rate during mass extinctions and background extinction being the normal, accepted rate of extinction

Where do the majority of animals live in the rain forest?

The Canopy

Explain in ecological terms of the Coexistence Principle, and what is the ramification of this principle. Use a specific example from Madagascar

The coexistence principle is that niche differences between species hinder competitive exclusion, helping maintain species diversity- competitive exclusion -lemurs that all eat bamboo but eat different parts of it -resources have been partitioned- don't compete -lots of species can live in the same place because they occupy different niches

Terborgh Results and Conclusions

The islands without predators had considerably less vegetation than the islands with herbivores and predators. There is absolutely a Top Down relationship between species, but this does not rule out a Bottom Up relationship as well.

For more information please see a report discussing this paper can be found in "Crafting the Pieces of the Diversity Jigsaw Puzzle." R. L. Kitching, Science 25 August 2006: 1055-1057

There was no difference in the distribution of host specificities between the two regions. The huge richness of herbivorous insects in tropical rainforests is driven by the phylogenetic diversity of the plant assemblage in those forests and not by any fundamental differences in the nature of the niches of the herbivores

How was Terborgh's experiments done?

They all examined small islands that had formed in a lake because it was dammed. These small islands created a variety of ecosystems. Some of these ecosystems had predators while others only have herbivores.

Ring tailed lemurs live where?

They mostly live on the ground and in trees, but they can also live in high rocky areas. How do they drink? By eating cactus, drinking condensed fog on leaves or by coming down from higher areas to to find small pools of water.

How can three species of Bamboo lemurs occupy the same area eating bamboo as their main source of nutrition

Two of them eat the lower parts of the bamboo that's tough but has low concentrations of cyanide while one species eat the shoots, the only one capable of digesting higher concentrations of cyanide

What is the general structure of a rainforest?

Vertical layers: overstory, canopy, understory, shrub layer, and ground level

Understanding why there is such pronounced biodiversity in the tropics has been a conundrum. There has been many hypotheses proposed over the years but one of the most fascinating ones reveals that the tropics are both a cradle and a museum of species. "Fossil Record Reveals Tropics as Cradle and Museum" Charles R. Marshall Science 6 October 2006: 66-67 Explain the research supporting this:

Why the researchers are looking at this issue? Most groups of organisms show a pronounced decrease in biodiversity from the tropics to the poles. This means that extinction in the tropics could have vast effects worldwide. The hypothesis: Much of the diversity of bivalves outside of the tropics is driven by the expansion of the geographic ranges of species that originated in the tropics. Thus, they argue that the tropics are both a cradle (high speciation rates) of biodiversity and a museum (low extinction rates). The experiment: They analyzed the fossil record of 163 genera and subgenera of bivalve mollusks that originated since the beginning of the late Miocene, 11 million years ago ... genera from only the best-preserved families, those that have at least 75% of their living genera represented in the fossil record. The conclusion: They show that ∼80% of genera that originated in the tropics later expanded into the extratropic... This represents so many taxa that only about a third of extratropical genera actually had their origins there. Strikingly, there are virtually no cases of the reverse scenario—extratropical origins followed by range expansions into the tropics. What are the ramifications of this research? That a major extinction in the tropics would have a major effect on the extratropics as well. This raises interesting questions about the effect of tropical invasions in the extratropics. If there were no tropical invasions, would the diversity in the extratropics be greatly reduced or would there simply be a greater number of extratropical originations?

Niches

decrease competition- specific organisms develop their own survival necessities that differentiate them from other organisms so that they don't have to compete for the same resources roles that an organism plays in a community, factors limiting its life and how it acquires food. How an organism functions in its environment

Trophic levels

each level of producer and consumers is a trophic level 1. Ecological pyramid- producer at bottom, highest level consumer at top 2. Pyramid of numbers- how many organisms occupy each level 3. Pyramid of biomass- multiplies average weight for each organism times the number of orgs at each level 4. Energy pyramid- shows decrease energy at each trophic level moving up

Who are the most successful mammals of Madagascar and why?

mammals like lemurs who have found distinct niches

Competition

organisms compete for resources, habitats, mates, reproduction, etc. and natural selection takes course- survival of the fittest

Predation

predators reduce prey. An interaction between two organisms that results in a flow of energy between them

Predator-prey interactions

prey adapt defenses like fighting, escaping, armor, intimidation techniques, masting/herding, camouflage. Predators reduce prey in order to increase species richness as seen in Yellowstone with the rise of the wolf population

Flow of energy into ecosystems

producers absorb solar energy and transformed into energy via nutrients. All energy is eventually lost as heat Starts with producers, ends with consumers

Pyramids

shows biomass at each trophic level in a given ecosystem /shows the relative number of organisms at each stage of a food chain.

Explain global warming

the recent and ongoing rise in global average temperature near Earth's surface

Tropical rainforests sustain as much as 50 percent of the species on our earth. Ecologists have been searching for the holy grail: The answer to why are there so many species in the tropics. One hypothesis is that there is the more plant diversity the more and in turn more animal diversity. Novotony et al researched this question in his article "Why Are There So Many Species of Herbivorous Insects in Tropical Rainforests?" Science 25 August 2006: Vol. 313 no. 5790 pp. 1115-1118. Please be able to explain the rationale behind this research, what he was testing the basic experiment and conclusion of the research. Lastly, what does the phrase "Escape and Radiate" have to do with this work.

*bottom up* Rationale: herbivore species coexistence in more diverse communities could reflect narrow host specificity relative to less diverse communities Experiment: Studied species diversity temperal and tropic sites Conclusion: Latitudinal gradient in insect species richness could be a direct function of plant diversity Meaning: Diverse insects because there are diverse plants, not because of host specificity Escape and radiate: an organism under constraints from other organisms will develop new defenses, allowing it to "escape" and then "radiate" into differing species. After a novel defense has been acquired, an organism is able to escape predation and rapidly multiply into new species because of relaxed selective pressure

Predators are often viewed as the meanest and ugliest. But this is not always true. Be able to identify and give a Madagascar example of four types of predators.

1. Carnivores- kill prey during attack (fossas eat lemurs) 2. Herbivores- remove parts of many prey, rarely lethal (lemurs eat fruit) 3. Parasites- consume parts of one or few prey, rarely lethal (blood parasites in birds) 4. Parasitoids- kill one prey during prolonged attack (wasps lay eggs inside caterpillar)

Name three types of competition and define each.

1. Interspecific competition - occurs when two species attempt to use the same resource and there is not enough resources to satisfy them both 2. Interference competition - two species physically interfere with one another by aggressively attempting to exclude one another from particular- defining your area and doing something about it (pheromones, behavior) 3. Exploitative competition -consumption of a limiting resource by one species makes that resource unavailable for consumption by another- two species use a resource until it's depleted- one gets all of it the other gets none

Since formalizing conservation biology as a true science, we have been working towards a unified pathway to approaching issues in conservation. Given our limited resources, conservationists have drawn up a list of "hot spots. What are the criteria for these regions. Where are they found and why is this concept needed. Buts what is the most glaring issue with conserving "hot spots."

1. Lost 70% of habitat 2. Contain plant endemic species comprising 0.5% of plant species worldwide. Found mostly in the tropics, and most are coastal or islands. Lots of impoverished places. Problem is what we are missing - missing the arctic, tundra, desert, savannah

There is a common perception that all tropical rainforest are the same lush green environment. This is a sad misconception. Please describe three differences and two similarities of the of Madagascar, and Hawaii. (climate and evolutionary history etc.) Please give a specific example how this affects the flora and fauna.

1. Madagascar broke off from land, whereas Hawaiian islands developed in isolation in the ocean (hawaiian species developed in isolation) 2. Hawaiian islands are new, while madagascar is the oldest island 3. Hawaii is volcanic and Madagascar isn't 1. Both have many endemic species 2. Both have mountains that create a rain-shadow effect (Balboa trees dry side, Lemurs wet side in Madagascar) (need an example for Hawaii)

List 5 of the IPCC (Intergovernmental Panel on Climate Change) projected impacts on our world.

1. Sea level rise 2. Increased global temperatures 3. Prolonged drought 4. Warming of the oceans 5. Extreme weather events

Give three lines of evidence for Global Warming

1. Temperature trends over the past thousand years 2. Massive glaciers melting in Greenland and Antarctica 3. Ocean warming

A few thousand years ago, tropical rainforests covered as much as 12 percent of the Earth's land surface, today how much is rainforest?

5%

Today, what is the percentage of 'landlubbers" compared to sea dwellers?

95% landlubbers