Refresher for Exam 3

True or false The following graphic illustrates the negative consequences of additional nutrient input into an environment

• True

• False

The following image is best described as

• Character displacement

• Interspecific competition

• Intraspecific competition

• Parasitism

• Niche partitioning

Answer explanation

Character displacement is a little tricky to understand because the physiological changes are partially the result of interspecific competition and niche partitioning, but they are dependent on the presence of another species. Alone, the two finch species have a set average beak size, but when the two species are co-existing, there are shifts in their beak sizes to minimize their interactions with one another.

The effectiveness of an invasive species is typically attributed to the lack of ______ and ability to ______their environment

Species diversity is greater in homogeneous environments

• True

• False

The measure of diversity across a large area is

• Alpha diversity

• Gamma diversity

• Beta diversity

• Epsilon diversity

• Delta diversity

Illustrate the graph that shows NPP as a function of average annual precipitation

Answer explanation

You should have drawn something similar to this graph where we have a rapid rise in NPP rates as we increase in precipitation that then decreases after some point. This decrease is because the environment is now overwatered and diminishes NPP rates (leaching of nutrients, drowning plants, low sunlight, etc).

The following image describes an effect of higher community diversity

• Local extinction

• Community stability

• Overpopulation

• Competitive exclusion

• Succession

Answer explanation

A bit hard to interpret at a quick glance, but the cartoon is an example of community stability with higher species diversity. When both colored species are separated, their abundances are influenced by climate conditions, such that their population would decline in unfavorable climate (low blue in hot years while low green in cold years). Assuming these two species can occupy similar niches, the loss of the individual species when in isolated conditions can be catastrophic to their environment (if they were pollinators, then we would see noticeable decline in plant populations). However, if both species were present in the same environment, then the losses of one species can be buffered by the presence of the other.

Outside of leaching, the nitrogen cycle can lose nitrogen via this process

• Erosion

• Eutrophication

• Gaseous efflux

• Weathering

• Mineralization

If Litter A have a high lignin:N ratio compared to Litter B, then Litter B has a _____ decomposition rate

The types of efficiencies we calculate for are all the following EXCEPT (2 answers!)

• Assimilation efficiency

• Production efficiency

• Ingestion efficiency

• Consumption efficiency

• Respiration efficiency