Ecology Answers

I'm supposed to study properties and principles of ecosystem.

I've gathered some information from a book called Ecosystem Ecology that mentioned the following points under the heading fundamental laws(i.e. principles):
1.The components of ecosystem are connected to each other.
2.All ecosystems are open systems embedded in environment , i.e they receive energy and discharge energy.
3.Ecosystems have levels of organisation and operate hierarchically.
4.Mass including biomass and energy are conserved.
5.All ecosystem processes are irreversible.
6.An ecosystem can grow and develop by increase in biomass, increase in cycling and genetic information.
But I'm not sure if these points qualify for properties as well.

Ecosystems have many levels of organisation and operate hierarchically.

What is meant by to operate hierarchically?

Is there anything called biological oscillation in ethology?

Please reply with a no if it is so.

Is there anything called biological oscillation in ecology?

Please reply even though the answer is no.

Is there books to study basic concepts of biodiversity like Alpha,beta, gamma, genetic, species and ecosystem biodiversities?

It would be great if you could name some available online.

One indication that a population is in a period of exponential growth is that..?
A. The birth rate is slightly higher than the death rate
B. The death rate is almost equal to the birth rate
C. The death rate exceeds the birth rate
D. The birth rate far exceeds the death rate

The characteristics that scientists use to distinguish different freshwater environments from each other are...?
A. Depth of water and rate of water movement
B. Temperature and water depth
C. Rate of water movement and availability of light
D. Precipitation and availability of light

In spite of natural factors that might influence human population growth rates, population growth in some countries appears to be declining because ..?
A. Humans have exceeded their carrying capacity
B. The incidence of disease epidemics has increased worldwide
C. Families and individuals make choices to have fewer children
D. Nutrition has declined in many populations